^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * kernel/lockdep.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Runtime locking correctness validator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Started by Ingo Molnar:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * this code maps all the lock dependencies as they occur in a live kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * and will warn about the following classes of locking bugs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * - lock inversion scenarios
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * - circular lock dependencies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * - hardirq/softirq safe/unsafe locking bugs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * Bugs are reported even if the current locking scenario does not cause
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * any deadlock at this point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * I.e. if anytime in the past two locks were taken in a different order,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * even if it happened for another task, even if those were different
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * locks (but of the same class as this lock), this code will detect it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * Thanks to Arjan van de Ven for coming up with the initial idea of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * mapping lock dependencies runtime.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #define DISABLE_BRANCH_PROFILING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/sched/clock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/proc_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/seq_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/kallsyms.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <linux/stacktrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <linux/debug_locks.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <linux/irqflags.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <linux/utsname.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <linux/hash.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include <linux/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/stringify.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <linux/bitmap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #include <linux/gfp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #include <linux/random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #include <linux/jhash.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #include <linux/nmi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) #include <linux/rcupdate.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) #include <linux/kprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #include <asm/sections.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) #include "lockdep_internals.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) #define CREATE_TRACE_POINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) #include <trace/events/lock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) int prove_locking = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) module_param(prove_locking, int, 0644);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) #define prove_locking 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) #ifdef CONFIG_LOCK_STAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) int lock_stat = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) module_param(lock_stat, int, 0644);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) #define lock_stat 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) DEFINE_PER_CPU(unsigned int, lockdep_recursion);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) EXPORT_PER_CPU_SYMBOL_GPL(lockdep_recursion);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) static __always_inline bool lockdep_enabled(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) if (!debug_locks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (this_cpu_read(lockdep_recursion))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (current->lockdep_recursion)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * lockdep_lock: protects the lockdep graph, the hashes and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * class/list/hash allocators.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * This is one of the rare exceptions where it's justified
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * to use a raw spinlock - we really dont want the spinlock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * code to recurse back into the lockdep code...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) static arch_spinlock_t __lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static struct task_struct *__owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) static inline void lockdep_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) DEBUG_LOCKS_WARN_ON(!irqs_disabled());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) __this_cpu_inc(lockdep_recursion);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) arch_spin_lock(&__lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) __owner = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) static inline void lockdep_unlock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) DEBUG_LOCKS_WARN_ON(!irqs_disabled());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (debug_locks && DEBUG_LOCKS_WARN_ON(__owner != current))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) __owner = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) arch_spin_unlock(&__lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) __this_cpu_dec(lockdep_recursion);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) static inline bool lockdep_assert_locked(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) return DEBUG_LOCKS_WARN_ON(__owner != current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) static struct task_struct *lockdep_selftest_task_struct;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) static int graph_lock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) * Make sure that if another CPU detected a bug while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) * walking the graph we dont change it (while the other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * CPU is busy printing out stuff with the graph lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * dropped already)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) if (!debug_locks) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) static inline void graph_unlock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * Turn lock debugging off and return with 0 if it was off already,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * and also release the graph lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) static inline int debug_locks_off_graph_unlock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) int ret = debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) unsigned long nr_list_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) static DECLARE_BITMAP(list_entries_in_use, MAX_LOCKDEP_ENTRIES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * All data structures here are protected by the global debug_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * nr_lock_classes is the number of elements of lock_classes[] that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) * in use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) #define KEYHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) #define KEYHASH_SIZE (1UL << KEYHASH_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) static struct hlist_head lock_keys_hash[KEYHASH_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) unsigned long nr_lock_classes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) unsigned long nr_zapped_classes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) unsigned long max_lock_class_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) DECLARE_BITMAP(lock_classes_in_use, MAX_LOCKDEP_KEYS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) static inline struct lock_class *hlock_class(struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) unsigned int class_idx = hlock->class_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) /* Don't re-read hlock->class_idx, can't use READ_ONCE() on bitfield */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) barrier();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) if (!test_bit(class_idx, lock_classes_in_use)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * Someone passed in garbage, we give up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) DEBUG_LOCKS_WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) * At this point, if the passed hlock->class_idx is still garbage,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) * we just have to live with it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) return lock_classes + class_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) #ifdef CONFIG_LOCK_STAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) static inline u64 lockstat_clock(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) return local_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) static int lock_point(unsigned long points[], unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) for (i = 0; i < LOCKSTAT_POINTS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) if (points[i] == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) points[i] = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) if (points[i] == ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) static void lock_time_inc(struct lock_time *lt, u64 time)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) if (time > lt->max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) lt->max = time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) if (time < lt->min || !lt->nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) lt->min = time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) lt->total += time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) lt->nr++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) static inline void lock_time_add(struct lock_time *src, struct lock_time *dst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) if (!src->nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) if (src->max > dst->max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) dst->max = src->max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) if (src->min < dst->min || !dst->nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) dst->min = src->min;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) dst->total += src->total;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) dst->nr += src->nr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) struct lock_class_stats lock_stats(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) struct lock_class_stats stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) int cpu, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) memset(&stats, 0, sizeof(struct lock_class_stats));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) struct lock_class_stats *pcs =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) stats.contention_point[i] += pcs->contention_point[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) stats.contending_point[i] += pcs->contending_point[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) lock_time_add(&pcs->read_waittime, &stats.read_waittime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) lock_time_add(&pcs->write_waittime, &stats.write_waittime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) lock_time_add(&pcs->read_holdtime, &stats.read_holdtime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) lock_time_add(&pcs->write_holdtime, &stats.write_holdtime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) for (i = 0; i < ARRAY_SIZE(stats.bounces); i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) stats.bounces[i] += pcs->bounces[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) return stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) void clear_lock_stats(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) struct lock_class_stats *cpu_stats =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) memset(cpu_stats, 0, sizeof(struct lock_class_stats));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) memset(class->contention_point, 0, sizeof(class->contention_point));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) memset(class->contending_point, 0, sizeof(class->contending_point));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) static struct lock_class_stats *get_lock_stats(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) return &this_cpu_ptr(cpu_lock_stats)[class - lock_classes];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) static void lock_release_holdtime(struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) struct lock_class_stats *stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) u64 holdtime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) if (!lock_stat)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) holdtime = lockstat_clock() - hlock->holdtime_stamp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) stats = get_lock_stats(hlock_class(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) if (hlock->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) lock_time_inc(&stats->read_holdtime, holdtime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) lock_time_inc(&stats->write_holdtime, holdtime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) static inline void lock_release_holdtime(struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) * We keep a global list of all lock classes. The list is only accessed with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * the lockdep spinlock lock held. free_lock_classes is a list with free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * elements. These elements are linked together by the lock_entry member in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * struct lock_class.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) static LIST_HEAD(all_lock_classes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) static LIST_HEAD(free_lock_classes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) * struct pending_free - information about data structures about to be freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * @zapped: Head of a list with struct lock_class elements.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * @lock_chains_being_freed: Bitmap that indicates which lock_chains[] elements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * are about to be freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) struct pending_free {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) struct list_head zapped;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) DECLARE_BITMAP(lock_chains_being_freed, MAX_LOCKDEP_CHAINS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * struct delayed_free - data structures used for delayed freeing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) * A data structure for delayed freeing of data structures that may be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * accessed by RCU readers at the time these were freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * @rcu_head: Used to schedule an RCU callback for freeing data structures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) * @index: Index of @pf to which freed data structures are added.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * @scheduled: Whether or not an RCU callback has been scheduled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) * @pf: Array with information about data structures about to be freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) static struct delayed_free {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) struct rcu_head rcu_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) int index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) int scheduled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) struct pending_free pf[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) } delayed_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) * The lockdep classes are in a hash-table as well, for fast lookup:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) #define CLASSHASH_BITS (MAX_LOCKDEP_KEYS_BITS - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) #define CLASSHASH_SIZE (1UL << CLASSHASH_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) #define __classhashfn(key) hash_long((unsigned long)key, CLASSHASH_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) #define classhashentry(key) (classhash_table + __classhashfn((key)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) static struct hlist_head classhash_table[CLASSHASH_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * We put the lock dependency chains into a hash-table as well, to cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * their existence:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) #define CHAINHASH_BITS (MAX_LOCKDEP_CHAINS_BITS-1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) #define CHAINHASH_SIZE (1UL << CHAINHASH_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) #define __chainhashfn(chain) hash_long(chain, CHAINHASH_BITS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) #define chainhashentry(chain) (chainhash_table + __chainhashfn((chain)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) static struct hlist_head chainhash_table[CHAINHASH_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) * the id of held_lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) static inline u16 hlock_id(struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) BUILD_BUG_ON(MAX_LOCKDEP_KEYS_BITS + 2 > 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) return (hlock->class_idx | (hlock->read << MAX_LOCKDEP_KEYS_BITS));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) static inline unsigned int chain_hlock_class_idx(u16 hlock_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) return hlock_id & (MAX_LOCKDEP_KEYS - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * The hash key of the lock dependency chains is a hash itself too:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * it's a hash of all locks taken up to that lock, including that lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * It's a 64-bit hash, because it's important for the keys to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * unique.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) static inline u64 iterate_chain_key(u64 key, u32 idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) u32 k0 = key, k1 = key >> 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) __jhash_mix(idx, k0, k1); /* Macro that modifies arguments! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) return k0 | (u64)k1 << 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) void lockdep_init_task(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) task->lockdep_depth = 0; /* no locks held yet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) task->curr_chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) task->lockdep_recursion = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) static __always_inline void lockdep_recursion_inc(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) __this_cpu_inc(lockdep_recursion);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) static __always_inline void lockdep_recursion_finish(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) if (WARN_ON_ONCE(__this_cpu_dec_return(lockdep_recursion)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) __this_cpu_write(lockdep_recursion, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) void lockdep_set_selftest_task(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) lockdep_selftest_task_struct = task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * Debugging switches:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) #define VERBOSE 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) #define VERY_VERBOSE 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) #if VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) # define HARDIRQ_VERBOSE 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) # define SOFTIRQ_VERBOSE 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) # define HARDIRQ_VERBOSE 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) # define SOFTIRQ_VERBOSE 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) #if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) * Quick filtering for interesting events:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) static int class_filter(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) #if 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) /* Example */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) if (class->name_version == 1 &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) !strcmp(class->name, "lockname"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) if (class->name_version == 1 &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) !strcmp(class->name, "&struct->lockfield"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) /* Filter everything else. 1 would be to allow everything else */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) static int verbose(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) #if VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) return class_filter(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) static void print_lockdep_off(const char *bug_msg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) printk(KERN_DEBUG "%s\n", bug_msg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) printk(KERN_DEBUG "turning off the locking correctness validator.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) #ifdef CONFIG_LOCK_STAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) printk(KERN_DEBUG "Please attach the output of /proc/lock_stat to the bug report\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) unsigned long nr_stack_trace_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) * struct lock_trace - single stack backtrace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) * @hash_entry: Entry in a stack_trace_hash[] list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) * @hash: jhash() of @entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) * @nr_entries: Number of entries in @entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) * @entries: Actual stack backtrace.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) struct lock_trace {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) struct hlist_node hash_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) u32 hash;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) u32 nr_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) unsigned long entries[] __aligned(sizeof(unsigned long));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) #define LOCK_TRACE_SIZE_IN_LONGS \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) (sizeof(struct lock_trace) / sizeof(unsigned long))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) * Stack-trace: sequence of lock_trace structures. Protected by the graph_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) static unsigned long stack_trace[MAX_STACK_TRACE_ENTRIES];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) static struct hlist_head stack_trace_hash[STACK_TRACE_HASH_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) static bool traces_identical(struct lock_trace *t1, struct lock_trace *t2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) return t1->hash == t2->hash && t1->nr_entries == t2->nr_entries &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) memcmp(t1->entries, t2->entries,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) t1->nr_entries * sizeof(t1->entries[0])) == 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) static struct lock_trace *save_trace(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) struct lock_trace *trace, *t2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) struct hlist_head *hash_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) u32 hash;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) int max_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) BUILD_BUG_ON_NOT_POWER_OF_2(STACK_TRACE_HASH_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) BUILD_BUG_ON(LOCK_TRACE_SIZE_IN_LONGS >= MAX_STACK_TRACE_ENTRIES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) trace = (struct lock_trace *)(stack_trace + nr_stack_trace_entries);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) LOCK_TRACE_SIZE_IN_LONGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) if (max_entries <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) if (!debug_locks_off_graph_unlock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) print_lockdep_off("BUG: MAX_STACK_TRACE_ENTRIES too low!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) trace->nr_entries = stack_trace_save(trace->entries, max_entries, 3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) hash = jhash(trace->entries, trace->nr_entries *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) sizeof(trace->entries[0]), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) trace->hash = hash;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) hash_head = stack_trace_hash + (hash & (STACK_TRACE_HASH_SIZE - 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) hlist_for_each_entry(t2, hash_head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) if (traces_identical(trace, t2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) return t2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) nr_stack_trace_entries += LOCK_TRACE_SIZE_IN_LONGS + trace->nr_entries;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) hlist_add_head(&trace->hash_entry, hash_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) return trace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) /* Return the number of stack traces in the stack_trace[] array. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) u64 lockdep_stack_trace_count(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) struct lock_trace *trace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) u64 c = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) for (i = 0; i < ARRAY_SIZE(stack_trace_hash); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) hlist_for_each_entry(trace, &stack_trace_hash[i], hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) c++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) return c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) /* Return the number of stack hash chains that have at least one stack trace. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) u64 lockdep_stack_hash_count(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) u64 c = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) for (i = 0; i < ARRAY_SIZE(stack_trace_hash); i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) if (!hlist_empty(&stack_trace_hash[i]))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) c++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) return c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) unsigned int nr_hardirq_chains;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) unsigned int nr_softirq_chains;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) unsigned int nr_process_chains;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) unsigned int max_lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) * Various lockdep statistics:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) * Locking printouts:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) #define __USAGE(__STATE) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) [LOCK_USED_IN_##__STATE] = "IN-"__stringify(__STATE)"-W", \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) [LOCK_ENABLED_##__STATE] = __stringify(__STATE)"-ON-W", \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) [LOCK_USED_IN_##__STATE##_READ] = "IN-"__stringify(__STATE)"-R",\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) [LOCK_ENABLED_##__STATE##_READ] = __stringify(__STATE)"-ON-R",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) static const char *usage_str[] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) #define LOCKDEP_STATE(__STATE) __USAGE(__STATE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) #include "lockdep_states.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) #undef LOCKDEP_STATE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) [LOCK_USED] = "INITIAL USE",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) [LOCK_USED_READ] = "INITIAL READ USE",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) /* abused as string storage for verify_lock_unused() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) [LOCK_USAGE_STATES] = "IN-NMI",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) const char *__get_key_name(const struct lockdep_subclass_key *key, char *str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) static inline unsigned long lock_flag(enum lock_usage_bit bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) return 1UL << bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) * The usage character defaults to '.' (i.e., irqs disabled and not in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) * irq context), which is the safest usage category.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) char c = '.';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) * The order of the following usage checks matters, which will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) * result in the outcome character as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) * - '+': irq is enabled and not in irq context
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) * - '-': in irq context and irq is disabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) * - '?': in irq context and irq is enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) if (class->usage_mask & lock_flag(bit + LOCK_USAGE_DIR_MASK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) c = '+';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) if (class->usage_mask & lock_flag(bit))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) c = '?';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) } else if (class->usage_mask & lock_flag(bit))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) c = '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) return c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) int i = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) #define LOCKDEP_STATE(__STATE) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) #include "lockdep_states.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) #undef LOCKDEP_STATE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) usage[i] = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) static void __print_lock_name(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) char str[KSYM_NAME_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) name = class->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) if (!name) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) name = __get_key_name(class->key, str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) printk(KERN_CONT "%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) printk(KERN_CONT "%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) if (class->name_version > 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) printk(KERN_CONT "#%d", class->name_version);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) if (class->subclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) printk(KERN_CONT "/%d", class->subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) static void print_lock_name(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) char usage[LOCK_USAGE_CHARS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) get_usage_chars(class, usage);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) printk(KERN_CONT " (");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) __print_lock_name(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) printk(KERN_CONT "){%s}-{%d:%d}", usage,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) class->wait_type_outer ?: class->wait_type_inner,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) class->wait_type_inner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) static void print_lockdep_cache(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) char str[KSYM_NAME_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) name = lock->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) if (!name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) name = __get_key_name(lock->key->subkeys, str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) printk(KERN_CONT "%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) static void print_lock(struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) * We can be called locklessly through debug_show_all_locks() so be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) * extra careful, the hlock might have been released and cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) * If this indeed happens, lets pretend it does not hurt to continue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) * to print the lock unless the hlock class_idx does not point to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) * registered class. The rationale here is: since we don't attempt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) * to distinguish whether we are in this situation, if it just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) * happened we can't count on class_idx to tell either.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) struct lock_class *lock = hlock_class(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) if (!lock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) printk(KERN_CONT "<RELEASED>\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) printk(KERN_CONT "%px", hlock->instance);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) print_lock_name(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) printk(KERN_CONT ", at: %pS\n", (void *)hlock->acquire_ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) static void lockdep_print_held_locks(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) int i, depth = READ_ONCE(p->lockdep_depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) if (!depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) printk("no locks held by %s/%d.\n", p->comm, task_pid_nr(p));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) printk("%d lock%s held by %s/%d:\n", depth,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) depth > 1 ? "s" : "", p->comm, task_pid_nr(p));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) * It's not reliable to print a task's held locks if it's not sleeping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) * and it's not the current task.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) if (p->state == TASK_RUNNING && p != current)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) for (i = 0; i < depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) printk(" #%d: ", i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) print_lock(p->held_locks + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) static void print_kernel_ident(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) printk("%s %.*s %s\n", init_utsname()->release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) (int)strcspn(init_utsname()->version, " "),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) init_utsname()->version,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) print_tainted());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) static int very_verbose(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) #if VERY_VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) return class_filter(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) * Is this the address of a static object:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) #ifdef __KERNEL__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) static int static_obj(const void *obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) unsigned long start = (unsigned long) &_stext,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) end = (unsigned long) &_end,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) addr = (unsigned long) obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) if (arch_is_kernel_initmem_freed(addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) * static variable?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) if ((addr >= start) && (addr < end))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) if (arch_is_kernel_data(addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) * in-kernel percpu var?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) if (is_kernel_percpu_address(addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) * module static or percpu var?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) return is_module_address(addr) || is_module_percpu_address(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) * To make lock name printouts unique, we calculate a unique
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) * class->name_version generation counter. The caller must hold the graph
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) * lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) static int count_matching_names(struct lock_class *new_class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) if (!new_class->name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) list_for_each_entry(class, &all_lock_classes, lock_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) if (new_class->key - new_class->subclass == class->key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) return class->name_version;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) if (class->name && !strcmp(class->name, new_class->name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) count = max(count, class->name_version);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) return count + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) /* used from NMI context -- must be lockless */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) static noinstr struct lock_class *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) struct lockdep_subclass_key *key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) struct hlist_head *hash_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) instrumentation_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) printk(KERN_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) "BUG: looking up invalid subclass: %u\n", subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) printk(KERN_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) "turning off the locking correctness validator.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) instrumentation_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) * If it is not initialised then it has never been locked,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) * so it won't be present in the hash table.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) if (unlikely(!lock->key))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) * NOTE: the class-key must be unique. For dynamic locks, a static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) * lock_class_key variable is passed in through the mutex_init()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) * (or spin_lock_init()) call - which acts as the key. For static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) * locks we use the lock object itself as the key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) BUILD_BUG_ON(sizeof(struct lock_class_key) >
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) sizeof(struct lockdep_map));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) key = lock->key->subkeys + subclass;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) hash_head = classhashentry(key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) * We do an RCU walk of the hash, see lockdep_free_key_range().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) hlist_for_each_entry_rcu_notrace(class, hash_head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) if (class->key == key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) * Huh! same key, different name? Did someone trample
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) * on some memory? We're most confused.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) WARN_ON_ONCE(class->name != lock->name &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) lock->key != &__lockdep_no_validate__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) return class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) * Static locks do not have their class-keys yet - for them the key is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) * the lock object itself. If the lock is in the per cpu area, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) * canonical address of the lock (per cpu offset removed) is used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) static bool assign_lock_key(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) unsigned long can_addr, addr = (unsigned long)lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) #ifdef __KERNEL__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) * lockdep_free_key_range() assumes that struct lock_class_key
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) * objects do not overlap. Since we use the address of lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) * objects as class key for static objects, check whether the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) * size of lock_class_key objects does not exceed the size of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) * the smallest lock object.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(raw_spinlock_t));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) if (__is_kernel_percpu_address(addr, &can_addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) lock->key = (void *)can_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) else if (__is_module_percpu_address(addr, &can_addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) lock->key = (void *)can_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) else if (static_obj(lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) lock->key = (void *)lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) /* Debug-check: all keys must be persistent! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) pr_err("INFO: trying to register non-static key.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) pr_err("The code is fine but needs lockdep annotation, or maybe\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) pr_err("you didn't initialize this object before use?\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) pr_err("turning off the locking correctness validator.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) /* Check whether element @e occurs in list @h */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) static bool in_list(struct list_head *e, struct list_head *h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) struct list_head *f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) list_for_each(f, h) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) if (e == f)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) * Check whether entry @e occurs in any of the locks_after or locks_before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) * lists.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) static bool in_any_class_list(struct list_head *e)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) class = &lock_classes[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) if (in_list(e, &class->locks_after) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) in_list(e, &class->locks_before))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) static bool class_lock_list_valid(struct lock_class *c, struct list_head *h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) struct lock_list *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) list_for_each_entry(e, h, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) if (e->links_to != c) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) printk(KERN_INFO "class %s: mismatch for lock entry %ld; class %s <> %s",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) c->name ? : "(?)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) (unsigned long)(e - list_entries),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) e->links_to && e->links_to->name ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) e->links_to->name : "(?)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) e->class && e->class->name ? e->class->name :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) "(?)");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) static bool check_lock_chain_key(struct lock_chain *chain)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) u64 chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) for (i = chain->base; i < chain->base + chain->depth; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) chain_key = iterate_chain_key(chain_key, chain_hlocks[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) * The 'unsigned long long' casts avoid that a compiler warning
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) * is reported when building tools/lib/lockdep.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) if (chain->chain_key != chain_key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) printk(KERN_INFO "chain %lld: key %#llx <> %#llx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) (unsigned long long)(chain - lock_chains),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) (unsigned long long)chain->chain_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) (unsigned long long)chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) static bool in_any_zapped_class_list(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) struct pending_free *pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) for (i = 0, pf = delayed_free.pf; i < ARRAY_SIZE(delayed_free.pf); i++, pf++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) if (in_list(&class->lock_entry, &pf->zapped))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) static bool __check_data_structures(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) struct lock_chain *chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) struct hlist_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) struct lock_list *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) /* Check whether all classes occur in a lock list. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) class = &lock_classes[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) if (!in_list(&class->lock_entry, &all_lock_classes) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) !in_list(&class->lock_entry, &free_lock_classes) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) !in_any_zapped_class_list(class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) printk(KERN_INFO "class %px/%s is not in any class list\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) class, class->name ? : "(?)");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) /* Check whether all classes have valid lock lists. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) class = &lock_classes[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) if (!class_lock_list_valid(class, &class->locks_before))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) if (!class_lock_list_valid(class, &class->locks_after))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) /* Check the chain_key of all lock chains. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) for (i = 0; i < ARRAY_SIZE(chainhash_table); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) head = chainhash_table + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) hlist_for_each_entry_rcu(chain, head, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) if (!check_lock_chain_key(chain))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) * Check whether all list entries that are in use occur in a class
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) * lock list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) for_each_set_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) e = list_entries + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) if (!in_any_class_list(&e->entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) printk(KERN_INFO "list entry %d is not in any class list; class %s <> %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) (unsigned int)(e - list_entries),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) e->class->name ? : "(?)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) e->links_to->name ? : "(?)");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) * Check whether all list entries that are not in use do not occur in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) * a class lock list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) for_each_clear_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) e = list_entries + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) if (in_any_class_list(&e->entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) printk(KERN_INFO "list entry %d occurs in a class list; class %s <> %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) (unsigned int)(e - list_entries),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) e->class && e->class->name ? e->class->name :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) "(?)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) e->links_to && e->links_to->name ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) e->links_to->name : "(?)");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) int check_consistency = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) module_param(check_consistency, int, 0644);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) static void check_data_structures(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) static bool once = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) if (check_consistency && !once) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) if (!__check_data_structures()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) once = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) WARN_ON(once);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) #else /* CONFIG_DEBUG_LOCKDEP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) static inline void check_data_structures(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) #endif /* CONFIG_DEBUG_LOCKDEP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) static void init_chain_block_buckets(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) * Initialize the lock_classes[] array elements, the free_lock_classes list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) * and also the delayed_free structure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) static void init_data_structures_once(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) static bool __read_mostly ds_initialized, rcu_head_initialized;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) if (likely(rcu_head_initialized))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) if (system_state >= SYSTEM_SCHEDULING) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) init_rcu_head(&delayed_free.rcu_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) rcu_head_initialized = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) if (ds_initialized)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) ds_initialized = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) INIT_LIST_HEAD(&delayed_free.pf[0].zapped);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) INIT_LIST_HEAD(&delayed_free.pf[1].zapped);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) for (i = 0; i < ARRAY_SIZE(lock_classes); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) list_add_tail(&lock_classes[i].lock_entry, &free_lock_classes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) INIT_LIST_HEAD(&lock_classes[i].locks_after);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) INIT_LIST_HEAD(&lock_classes[i].locks_before);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) init_chain_block_buckets();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) static inline struct hlist_head *keyhashentry(const struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) unsigned long hash = hash_long((uintptr_t)key, KEYHASH_BITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) return lock_keys_hash + hash;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) /* Register a dynamically allocated key. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) void lockdep_register_key(struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) struct hlist_head *hash_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) struct lock_class_key *k;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) if (WARN_ON_ONCE(static_obj(key)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) hash_head = keyhashentry(key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) if (!graph_lock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) goto restore_irqs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) if (WARN_ON_ONCE(k == key))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) hlist_add_head_rcu(&key->hash_entry, hash_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) out_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) restore_irqs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) EXPORT_SYMBOL_GPL(lockdep_register_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) /* Check whether a key has been registered as a dynamic key. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) static bool is_dynamic_key(const struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) struct hlist_head *hash_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) struct lock_class_key *k;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) bool found = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) if (WARN_ON_ONCE(static_obj(key)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) * If lock debugging is disabled lock_keys_hash[] may contain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) * pointers to memory that has already been freed. Avoid triggering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) * a use-after-free in that case by returning early.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) if (!debug_locks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) hash_head = keyhashentry(key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) if (k == key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) found = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) return found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) * Register a lock's class in the hash-table, if the class is not present
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) * yet. Otherwise we look it up. We cache the result in the lock object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) * itself, so actual lookup of the hash should be once per lock object.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) static struct lock_class *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) struct lockdep_subclass_key *key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) struct hlist_head *hash_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) int idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) DEBUG_LOCKS_WARN_ON(!irqs_disabled());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) class = look_up_lock_class(lock, subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) if (likely(class))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) goto out_set_class_cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) if (!lock->key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) if (!assign_lock_key(lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) } else if (!static_obj(lock->key) && !is_dynamic_key(lock->key)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) key = lock->key->subkeys + subclass;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) hash_head = classhashentry(key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) if (!graph_lock()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) * We have to do the hash-walk again, to avoid races
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) * with another CPU:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) if (class->key == key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) goto out_unlock_set;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) init_data_structures_once();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) /* Allocate a new lock class and add it to the hash. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) class = list_first_entry_or_null(&free_lock_classes, typeof(*class),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) lock_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) if (!class) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) if (!debug_locks_off_graph_unlock()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) print_lockdep_off("BUG: MAX_LOCKDEP_KEYS too low!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) nr_lock_classes++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) __set_bit(class - lock_classes, lock_classes_in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) debug_atomic_inc(nr_unused_locks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) class->key = key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) class->name = lock->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) class->subclass = subclass;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) WARN_ON_ONCE(!list_empty(&class->locks_before));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) WARN_ON_ONCE(!list_empty(&class->locks_after));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) class->name_version = count_matching_names(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) class->wait_type_inner = lock->wait_type_inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) class->wait_type_outer = lock->wait_type_outer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) class->lock_type = lock->lock_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) * We use RCU's safe list-add method to make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) * parallel walking of the hash-list safe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) hlist_add_head_rcu(&class->hash_entry, hash_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) * Remove the class from the free list and add it to the global list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) * of classes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) list_move_tail(&class->lock_entry, &all_lock_classes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) idx = class - lock_classes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) if (idx > max_lock_class_idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) max_lock_class_idx = idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) if (verbose(class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) printk("\nnew class %px: %s", class->key, class->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) if (class->name_version > 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) printk(KERN_CONT "#%d", class->name_version);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) printk(KERN_CONT "\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) if (!graph_lock()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) out_unlock_set:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) out_set_class_cache:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) if (!subclass || force)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) lock->class_cache[0] = class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) else if (subclass < NR_LOCKDEP_CACHING_CLASSES)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) lock->class_cache[subclass] = class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) * Hash collision, did we smoke some? We found a class with a matching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) * hash but the subclass -- which is hashed in -- didn't match.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) return class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) * Allocate a lockdep entry. (assumes the graph_lock held, returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) * with NULL on failure)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) static struct lock_list *alloc_list_entry(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) int idx = find_first_zero_bit(list_entries_in_use,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) ARRAY_SIZE(list_entries));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) if (idx >= ARRAY_SIZE(list_entries)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) if (!debug_locks_off_graph_unlock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) print_lockdep_off("BUG: MAX_LOCKDEP_ENTRIES too low!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) nr_list_entries++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) __set_bit(idx, list_entries_in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) return list_entries + idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) * Add a new dependency to the head of the list:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) static int add_lock_to_list(struct lock_class *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) struct lock_class *links_to, struct list_head *head,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) unsigned long ip, u16 distance, u8 dep,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) const struct lock_trace *trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) struct lock_list *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) * Lock not present yet - get a new dependency struct and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) * add it to the list:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) entry = alloc_list_entry();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) entry->class = this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) entry->links_to = links_to;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) entry->dep = dep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) entry->distance = distance;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) entry->trace = trace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) * Both allocation and removal are done under the graph lock; but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) * iteration is under RCU-sched; see look_up_lock_class() and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) * lockdep_free_key_range().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) list_add_tail_rcu(&entry->entry, head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) * For good efficiency of modular, we use power of 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) #define MAX_CIRCULAR_QUEUE_SIZE 4096UL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) #define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) * The circular_queue and helpers are used to implement graph
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) * breadth-first search (BFS) algorithm, by which we can determine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) * whether there is a path from a lock to another. In deadlock checks,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) * a path from the next lock to be acquired to a previous held lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) * indicates that adding the <prev> -> <next> lock dependency will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) * produce a circle in the graph. Breadth-first search instead of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) * depth-first search is used in order to find the shortest (circular)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) * path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) struct circular_queue {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) struct lock_list *element[MAX_CIRCULAR_QUEUE_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) unsigned int front, rear;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) static struct circular_queue lock_cq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) unsigned int max_bfs_queue_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) static unsigned int lockdep_dependency_gen_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) static inline void __cq_init(struct circular_queue *cq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) cq->front = cq->rear = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) lockdep_dependency_gen_id++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) static inline int __cq_empty(struct circular_queue *cq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) return (cq->front == cq->rear);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) static inline int __cq_full(struct circular_queue *cq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) return ((cq->rear + 1) & CQ_MASK) == cq->front;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) static inline int __cq_enqueue(struct circular_queue *cq, struct lock_list *elem)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) if (__cq_full(cq))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) cq->element[cq->rear] = elem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) cq->rear = (cq->rear + 1) & CQ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) * Dequeue an element from the circular_queue, return a lock_list if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) * the queue is not empty, or NULL if otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) static inline struct lock_list * __cq_dequeue(struct circular_queue *cq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) struct lock_list * lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) if (__cq_empty(cq))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) lock = cq->element[cq->front];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) cq->front = (cq->front + 1) & CQ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) return lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) return (cq->rear - cq->front) & CQ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) static inline void mark_lock_accessed(struct lock_list *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) lock->class->dep_gen_id = lockdep_dependency_gen_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) static inline void visit_lock_entry(struct lock_list *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) struct lock_list *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) lock->parent = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) static inline unsigned long lock_accessed(struct lock_list *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) return lock->class->dep_gen_id == lockdep_dependency_gen_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) static inline struct lock_list *get_lock_parent(struct lock_list *child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) return child->parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) static inline int get_lock_depth(struct lock_list *child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) int depth = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) struct lock_list *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) while ((parent = get_lock_parent(child))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) child = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) depth++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) return depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) * Return the forward or backward dependency list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) * @lock: the lock_list to get its class's dependency list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) * @offset: the offset to struct lock_class to determine whether it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) * locks_after or locks_before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) static inline struct list_head *get_dep_list(struct lock_list *lock, int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) void *lock_class = lock->class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) return lock_class + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) * Return values of a bfs search:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) * BFS_E* indicates an error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) * BFS_R* indicates a result (match or not)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) * BFS_EINVALIDNODE: Find a invalid node in the graph.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) * BFS_EQUEUEFULL: The queue is full while doing the bfs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) * BFS_RMATCH: Find the matched node in the graph, and put that node into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) * *@target_entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) * BFS_RNOMATCH: Haven't found the matched node and keep *@target_entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) * _unchanged_.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) enum bfs_result {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) BFS_EINVALIDNODE = -2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) BFS_EQUEUEFULL = -1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) BFS_RMATCH = 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) BFS_RNOMATCH = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) * bfs_result < 0 means error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) static inline bool bfs_error(enum bfs_result res)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) return res < 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) * DEP_*_BIT in lock_list::dep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) * For dependency @prev -> @next:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) * SR: @prev is shared reader (->read != 0) and @next is recursive reader
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) * (->read == 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) * ER: @prev is exclusive locker (->read == 0) and @next is recursive reader
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) * SN: @prev is shared reader and @next is non-recursive locker (->read != 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) * EN: @prev is exclusive locker and @next is non-recursive locker
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) * Note that we define the value of DEP_*_BITs so that:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) * bit0 is prev->read == 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) * bit1 is next->read != 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) #define DEP_SR_BIT (0 + (0 << 1)) /* 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) #define DEP_ER_BIT (1 + (0 << 1)) /* 1 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) #define DEP_SN_BIT (0 + (1 << 1)) /* 2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) #define DEP_EN_BIT (1 + (1 << 1)) /* 3 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) #define DEP_SR_MASK (1U << (DEP_SR_BIT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) #define DEP_ER_MASK (1U << (DEP_ER_BIT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) #define DEP_SN_MASK (1U << (DEP_SN_BIT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) #define DEP_EN_MASK (1U << (DEP_EN_BIT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) static inline unsigned int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) __calc_dep_bit(struct held_lock *prev, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) return (prev->read == 0) + ((next->read != 2) << 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) static inline u8 calc_dep(struct held_lock *prev, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) return 1U << __calc_dep_bit(prev, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) * calculate the dep_bit for backwards edges. We care about whether @prev is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) * shared and whether @next is recursive.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) static inline unsigned int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) __calc_dep_bitb(struct held_lock *prev, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) return (next->read != 2) + ((prev->read == 0) << 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) static inline u8 calc_depb(struct held_lock *prev, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) return 1U << __calc_dep_bitb(prev, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) * Initialize a lock_list entry @lock belonging to @class as the root for a BFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) * search.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) static inline void __bfs_init_root(struct lock_list *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) lock->class = class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) lock->parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) lock->only_xr = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) * Initialize a lock_list entry @lock based on a lock acquisition @hlock as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) * root for a BFS search.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) * ->only_xr of the initial lock node is set to @hlock->read == 2, to make sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) * that <prev> -> @hlock and @hlock -> <whatever __bfs() found> is not -(*R)->
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) * and -(S*)->.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620) static inline void bfs_init_root(struct lock_list *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) __bfs_init_root(lock, hlock_class(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) lock->only_xr = (hlock->read == 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) * Similar to bfs_init_root() but initialize the root for backwards BFS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) * ->only_xr of the initial lock node is set to @hlock->read != 0, to make sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) * that <next> -> @hlock and @hlock -> <whatever backwards BFS found> is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) * -(*S)-> and -(R*)-> (reverse order of -(*R)-> and -(S*)->).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) static inline void bfs_init_rootb(struct lock_list *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) __bfs_init_root(lock, hlock_class(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) lock->only_xr = (hlock->read != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) static inline struct lock_list *__bfs_next(struct lock_list *lock, int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) if (!lock || !lock->parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) return list_next_or_null_rcu(get_dep_list(lock->parent, offset),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) &lock->entry, struct lock_list, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) * Breadth-First Search to find a strong path in the dependency graph.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) * @source_entry: the source of the path we are searching for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) * @data: data used for the second parameter of @match function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) * @match: match function for the search
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) * @target_entry: pointer to the target of a matched path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) * @offset: the offset to struct lock_class to determine whether it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) * locks_after or locks_before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) * We may have multiple edges (considering different kinds of dependencies,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) * e.g. ER and SN) between two nodes in the dependency graph. But
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) * only the strong dependency path in the graph is relevant to deadlocks. A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) * strong dependency path is a dependency path that doesn't have two adjacent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) * dependencies as -(*R)-> -(S*)->, please see:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) * Documentation/locking/lockdep-design.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) * for more explanation of the definition of strong dependency paths
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) * In __bfs(), we only traverse in the strong dependency path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) * In lock_list::only_xr, we record whether the previous dependency only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) * has -(*R)-> in the search, and if it does (prev only has -(*R)->), we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) * filter out any -(S*)-> in the current dependency and after that, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) * ->only_xr is set according to whether we only have -(*R)-> left.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) static enum bfs_result __bfs(struct lock_list *source_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) bool (*match)(struct lock_list *entry, void *data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) struct lock_list **target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) struct circular_queue *cq = &lock_cq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) struct lock_list *lock = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) struct lock_list *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) struct list_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) unsigned int cq_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) bool first;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) lockdep_assert_locked();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) __cq_init(cq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) __cq_enqueue(cq, source_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) while ((lock = __bfs_next(lock, offset)) || (lock = __cq_dequeue(cq))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) if (!lock->class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) return BFS_EINVALIDNODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) * Step 1: check whether we already finish on this one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) * If we have visited all the dependencies from this @lock to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) * others (iow, if we have visited all lock_list entries in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) * @lock->class->locks_{after,before}) we skip, otherwise go
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) * and visit all the dependencies in the list and mark this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) * list accessed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) if (lock_accessed(lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) mark_lock_accessed(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) * Step 2: check whether prev dependency and this form a strong
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) * dependency path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) if (lock->parent) { /* Parent exists, check prev dependency */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) u8 dep = lock->dep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) bool prev_only_xr = lock->parent->only_xr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) * Mask out all -(S*)-> if we only have *R in previous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) * step, because -(*R)-> -(S*)-> don't make up a strong
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) * dependency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) if (prev_only_xr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) dep &= ~(DEP_SR_MASK | DEP_SN_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) /* If nothing left, we skip */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) if (!dep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) /* If there are only -(*R)-> left, set that for the next step */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) lock->only_xr = !(dep & (DEP_SN_MASK | DEP_EN_MASK));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) * Step 3: we haven't visited this and there is a strong
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) * dependency path to this, so check with @match.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) if (match(lock, data)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) *target_entry = lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) return BFS_RMATCH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) * Step 4: if not match, expand the path by adding the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) * forward or backwards dependencis in the search
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) first = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) head = get_dep_list(lock, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) list_for_each_entry_rcu(entry, head, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) visit_lock_entry(entry, lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) * Note we only enqueue the first of the list into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) * queue, because we can always find a sibling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) * dependency from one (see __bfs_next()), as a result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) * the space of queue is saved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) if (!first)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) first = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) if (__cq_enqueue(cq, entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768) return BFS_EQUEUEFULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) cq_depth = __cq_get_elem_count(cq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771) if (max_bfs_queue_depth < cq_depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) max_bfs_queue_depth = cq_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) return BFS_RNOMATCH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) static inline enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780) __bfs_forwards(struct lock_list *src_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781) void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) bool (*match)(struct lock_list *entry, void *data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) struct lock_list **target_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) return __bfs(src_entry, data, match, target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) offsetof(struct lock_class, locks_after));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) static inline enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) __bfs_backwards(struct lock_list *src_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793) bool (*match)(struct lock_list *entry, void *data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) struct lock_list **target_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) return __bfs(src_entry, data, match, target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) offsetof(struct lock_class, locks_before));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) static void print_lock_trace(const struct lock_trace *trace,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) unsigned int spaces)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804) stack_trace_print(trace->entries, trace->nr_entries, spaces);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) * Print a dependency chain entry (this is only done when a deadlock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809) * has been detected):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811) static noinline void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812) print_circular_bug_entry(struct lock_list *target, int depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) printk("\n-> #%u", depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817) print_lock_name(target->class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) printk(KERN_CONT ":\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) print_lock_trace(target->trace, 6);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) print_circular_lock_scenario(struct held_lock *src,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) struct held_lock *tgt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) struct lock_list *prt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827) struct lock_class *source = hlock_class(src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) struct lock_class *target = hlock_class(tgt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829) struct lock_class *parent = prt->class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) * A direct locking problem where unsafe_class lock is taken
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) * directly by safe_class lock, then all we need to show
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834) * is the deadlock scenario, as it is obvious that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835) * unsafe lock is taken under the safe lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) * But if there is a chain instead, where the safe lock takes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) * an intermediate lock (middle_class) where this lock is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839) * not the same as the safe lock, then the lock chain is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840) * used to describe the problem. Otherwise we would need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) * to show a different CPU case for each link in the chain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842) * from the safe_class lock to the unsafe_class lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844) if (parent != source) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845) printk("Chain exists of:\n ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846) __print_lock_name(source);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847) printk(KERN_CONT " --> ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848) __print_lock_name(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) printk(KERN_CONT " --> ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) __print_lock_name(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) printk(KERN_CONT "\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) printk(" Possible unsafe locking scenario:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) printk(" CPU0 CPU1\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) printk(" ---- ----\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) __print_lock_name(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861) __print_lock_name(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) __print_lock_name(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867) __print_lock_name(source);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869) printk("\n *** DEADLOCK ***\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) * When a circular dependency is detected, print the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874) * header first:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876) static noinline void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) print_circular_bug_header(struct lock_list *entry, unsigned int depth,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) struct held_lock *check_src,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879) struct held_lock *check_tgt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887) pr_warn("======================================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) pr_warn("WARNING: possible circular locking dependency detected\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) pr_warn("------------------------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) pr_warn("%s/%d is trying to acquire lock:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892) curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893) print_lock(check_src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895) pr_warn("\nbut task is already holding lock:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) print_lock(check_tgt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) pr_warn("\nwhich lock already depends on the new lock.\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899) pr_warn("\nthe existing dependency chain (in reverse order) is:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) print_circular_bug_entry(entry, depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905) * We are about to add A -> B into the dependency graph, and in __bfs() a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) * strong dependency path A -> .. -> B is found: hlock_class equals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907) * entry->class.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) * If A -> .. -> B can replace A -> B in any __bfs() search (means the former
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910) * is _stronger_ than or equal to the latter), we consider A -> B as redundant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) * For example if A -> .. -> B is -(EN)-> (i.e. A -(E*)-> .. -(*N)-> B), and A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912) * -> B is -(ER)-> or -(EN)->, then we don't need to add A -> B into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913) * dependency graph, as any strong path ..-> A -> B ->.. we can get with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) * having dependency A -> B, we could already get a equivalent path ..-> A ->
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915) * .. -> B -> .. with A -> .. -> B. Therefore A -> B is reduntant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917) * We need to make sure both the start and the end of A -> .. -> B is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918) * weaker than A -> B. For the start part, please see the comment in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) * check_redundant(). For the end part, we need:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) * Either
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923) * a) A -> B is -(*R)-> (everything is not weaker than that)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925) * or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) * b) A -> .. -> B is -(*N)-> (nothing is stronger than this)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930) static inline bool hlock_equal(struct lock_list *entry, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) struct held_lock *hlock = (struct held_lock *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934) return hlock_class(hlock) == entry->class && /* Found A -> .. -> B */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935) (hlock->read == 2 || /* A -> B is -(*R)-> */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936) !entry->only_xr); /* A -> .. -> B is -(*N)-> */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940) * We are about to add B -> A into the dependency graph, and in __bfs() a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) * strong dependency path A -> .. -> B is found: hlock_class equals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942) * entry->class.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944) * We will have a deadlock case (conflict) if A -> .. -> B -> A is a strong
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) * dependency cycle, that means:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947) * Either
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) * a) B -> A is -(E*)->
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) * or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) * b) A -> .. -> B is -(*N)-> (i.e. A -> .. -(*N)-> B)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955) * as then we don't have -(*R)-> -(S*)-> in the cycle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957) static inline bool hlock_conflict(struct lock_list *entry, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959) struct held_lock *hlock = (struct held_lock *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) return hlock_class(hlock) == entry->class && /* Found A -> .. -> B */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) (hlock->read == 0 || /* B -> A is -(E*)-> */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963) !entry->only_xr); /* A -> .. -> B is -(*N)-> */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966) static noinline void print_circular_bug(struct lock_list *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) struct lock_list *target,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) struct held_lock *check_src,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) struct held_lock *check_tgt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) struct lock_list *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973) struct lock_list *first_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) if (!debug_locks_off_graph_unlock() || debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) this->trace = save_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) if (!this->trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983) depth = get_lock_depth(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985) print_circular_bug_header(target, depth, check_src, check_tgt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) parent = get_lock_parent(target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988) first_parent = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990) while (parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991) print_circular_bug_entry(parent, --depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) parent = get_lock_parent(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1995) printk("\nother info that might help us debug this:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1996) print_circular_lock_scenario(check_src, check_tgt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1997) first_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1998)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1999) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2001) printk("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2002) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2003) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2004)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2005) static noinline void print_bfs_bug(int ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2006) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2007) if (!debug_locks_off_graph_unlock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2008) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2009)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2010) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2011) * Breadth-first-search failed, graph got corrupted?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2012) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2013) WARN(1, "lockdep bfs error:%d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2014) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2015)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2016) static bool noop_count(struct lock_list *entry, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2017) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2018) (*(unsigned long *)data)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2019) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2020) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2022) static unsigned long __lockdep_count_forward_deps(struct lock_list *this)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2023) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2024) unsigned long count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2025) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2026)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2027) __bfs_forwards(this, (void *)&count, noop_count, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2028)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2029) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2030) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2031) unsigned long lockdep_count_forward_deps(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2032) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2033) unsigned long ret, flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2034) struct lock_list this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2035)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2036) __bfs_init_root(&this, class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2037)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2038) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2039) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2040) ret = __lockdep_count_forward_deps(&this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2041) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2042) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2043)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2044) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2045) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2046)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2047) static unsigned long __lockdep_count_backward_deps(struct lock_list *this)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2048) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2049) unsigned long count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2050) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2051)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2052) __bfs_backwards(this, (void *)&count, noop_count, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2054) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2055) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2056)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2057) unsigned long lockdep_count_backward_deps(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2058) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2059) unsigned long ret, flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2060) struct lock_list this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2061)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2062) __bfs_init_root(&this, class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2063)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2064) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2065) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2066) ret = __lockdep_count_backward_deps(&this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2067) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2068) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2069)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2070) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2071) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2073) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2074) * Check that the dependency graph starting at <src> can lead to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2075) * <target> or not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2076) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2077) static noinline enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2078) check_path(struct held_lock *target, struct lock_list *src_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2079) bool (*match)(struct lock_list *entry, void *data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2080) struct lock_list **target_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2081) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2082) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2083)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2084) ret = __bfs_forwards(src_entry, target, match, target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2085)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2086) if (unlikely(bfs_error(ret)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2087) print_bfs_bug(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2089) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2090) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2091)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2092) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2093) * Prove that the dependency graph starting at <src> can not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2094) * lead to <target>. If it can, there is a circle when adding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2095) * <target> -> <src> dependency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2096) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2097) * Print an error and return BFS_RMATCH if it does.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2098) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2099) static noinline enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2100) check_noncircular(struct held_lock *src, struct held_lock *target,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2101) struct lock_trace **const trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2103) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2104) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2105) struct lock_list src_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2107) bfs_init_root(&src_entry, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2109) debug_atomic_inc(nr_cyclic_checks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2111) ret = check_path(target, &src_entry, hlock_conflict, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2113) if (unlikely(ret == BFS_RMATCH)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2114) if (!*trace) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2115) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2116) * If save_trace fails here, the printing might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2117) * trigger a WARN but because of the !nr_entries it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2118) * should not do bad things.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2119) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2120) *trace = save_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2123) print_circular_bug(&src_entry, target_entry, src, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2126) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2127) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2129) #ifdef CONFIG_LOCKDEP_SMALL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2130) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2131) * Check that the dependency graph starting at <src> can lead to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2132) * <target> or not. If it can, <src> -> <target> dependency is already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2133) * in the graph.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2134) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2135) * Return BFS_RMATCH if it does, or BFS_RMATCH if it does not, return BFS_E* if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2136) * any error appears in the bfs search.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2137) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2138) static noinline enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2139) check_redundant(struct held_lock *src, struct held_lock *target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2140) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2141) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2142) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2143) struct lock_list src_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2145) bfs_init_root(&src_entry, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2146) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2147) * Special setup for check_redundant().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2148) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2149) * To report redundant, we need to find a strong dependency path that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2150) * is equal to or stronger than <src> -> <target>. So if <src> is E,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2151) * we need to let __bfs() only search for a path starting at a -(E*)->,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2152) * we achieve this by setting the initial node's ->only_xr to true in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2153) * that case. And if <prev> is S, we set initial ->only_xr to false
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2154) * because both -(S*)-> (equal) and -(E*)-> (stronger) are redundant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2155) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2156) src_entry.only_xr = src->read == 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2158) debug_atomic_inc(nr_redundant_checks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2160) ret = check_path(target, &src_entry, hlock_equal, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2162) if (ret == BFS_RMATCH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2163) debug_atomic_inc(nr_redundant);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2165) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2167) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2169) #ifdef CONFIG_TRACE_IRQFLAGS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2171) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2172) * Forwards and backwards subgraph searching, for the purposes of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2173) * proving that two subgraphs can be connected by a new dependency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2174) * without creating any illegal irq-safe -> irq-unsafe lock dependency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2175) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2176) * A irq safe->unsafe deadlock happens with the following conditions:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2177) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2178) * 1) We have a strong dependency path A -> ... -> B
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2179) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2180) * 2) and we have ENABLED_IRQ usage of B and USED_IN_IRQ usage of A, therefore
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2181) * irq can create a new dependency B -> A (consider the case that a holder
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2182) * of B gets interrupted by an irq whose handler will try to acquire A).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2183) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2184) * 3) the dependency circle A -> ... -> B -> A we get from 1) and 2) is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2185) * strong circle:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2186) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2187) * For the usage bits of B:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2188) * a) if A -> B is -(*N)->, then B -> A could be any type, so any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2189) * ENABLED_IRQ usage suffices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2190) * b) if A -> B is -(*R)->, then B -> A must be -(E*)->, so only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2191) * ENABLED_IRQ_*_READ usage suffices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2192) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2193) * For the usage bits of A:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2194) * c) if A -> B is -(E*)->, then B -> A could be any type, so any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2195) * USED_IN_IRQ usage suffices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2196) * d) if A -> B is -(S*)->, then B -> A must be -(*N)->, so only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2197) * USED_IN_IRQ_*_READ usage suffices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2198) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2200) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2201) * There is a strong dependency path in the dependency graph: A -> B, and now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2202) * we need to decide which usage bit of A should be accumulated to detect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2203) * safe->unsafe bugs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2204) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2205) * Note that usage_accumulate() is used in backwards search, so ->only_xr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2206) * stands for whether A -> B only has -(S*)-> (in this case ->only_xr is true).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2207) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2208) * As above, if only_xr is false, which means A -> B has -(E*)-> dependency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2209) * path, any usage of A should be considered. Otherwise, we should only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2210) * consider _READ usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2211) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2212) static inline bool usage_accumulate(struct lock_list *entry, void *mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2213) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2214) if (!entry->only_xr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2215) *(unsigned long *)mask |= entry->class->usage_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2216) else /* Mask out _READ usage bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2217) *(unsigned long *)mask |= (entry->class->usage_mask & LOCKF_IRQ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2219) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2222) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2223) * There is a strong dependency path in the dependency graph: A -> B, and now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2224) * we need to decide which usage bit of B conflicts with the usage bits of A,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2225) * i.e. which usage bit of B may introduce safe->unsafe deadlocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2226) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2227) * As above, if only_xr is false, which means A -> B has -(*N)-> dependency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2228) * path, any usage of B should be considered. Otherwise, we should only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2229) * consider _READ usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2230) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2231) static inline bool usage_match(struct lock_list *entry, void *mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2232) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2233) if (!entry->only_xr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2234) return !!(entry->class->usage_mask & *(unsigned long *)mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2235) else /* Mask out _READ usage bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2236) return !!((entry->class->usage_mask & LOCKF_IRQ) & *(unsigned long *)mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2239) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2240) * Find a node in the forwards-direction dependency sub-graph starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2241) * at @root->class that matches @bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2242) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2243) * Return BFS_MATCH if such a node exists in the subgraph, and put that node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2244) * into *@target_entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2245) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2246) static enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2247) find_usage_forwards(struct lock_list *root, unsigned long usage_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2248) struct lock_list **target_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2249) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2250) enum bfs_result result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2252) debug_atomic_inc(nr_find_usage_forwards_checks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2254) result = __bfs_forwards(root, &usage_mask, usage_match, target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2256) return result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2259) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2260) * Find a node in the backwards-direction dependency sub-graph starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2261) * at @root->class that matches @bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2262) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2263) static enum bfs_result
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2264) find_usage_backwards(struct lock_list *root, unsigned long usage_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2265) struct lock_list **target_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2266) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2267) enum bfs_result result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2269) debug_atomic_inc(nr_find_usage_backwards_checks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2271) result = __bfs_backwards(root, &usage_mask, usage_match, target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2273) return result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2276) static void print_lock_class_header(struct lock_class *class, int depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2277) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2278) int bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2280) printk("%*s->", depth, "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2281) print_lock_name(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2282) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2283) printk(KERN_CONT " ops: %lu", debug_class_ops_read(class));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2284) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2285) printk(KERN_CONT " {\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2287) for (bit = 0; bit < LOCK_TRACE_STATES; bit++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2288) if (class->usage_mask & (1 << bit)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2289) int len = depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2291) len += printk("%*s %s", depth, "", usage_str[bit]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2292) len += printk(KERN_CONT " at:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2293) print_lock_trace(class->usage_traces[bit], len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2294) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2295) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2296) printk("%*s }\n", depth, "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2298) printk("%*s ... key at: [<%px>] %pS\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2299) depth, "", class->key, class->key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2301)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2302) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2303) * Dependency path printing:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2304) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2305) * After BFS we get a lock dependency path (linked via ->parent of lock_list),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2306) * printing out each lock in the dependency path will help on understanding how
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2307) * the deadlock could happen. Here are some details about dependency path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2308) * printing:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2309) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2310) * 1) A lock_list can be either forwards or backwards for a lock dependency,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2311) * for a lock dependency A -> B, there are two lock_lists:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2312) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2313) * a) lock_list in the ->locks_after list of A, whose ->class is B and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2314) * ->links_to is A. In this case, we can say the lock_list is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2315) * "A -> B" (forwards case).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2316) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2317) * b) lock_list in the ->locks_before list of B, whose ->class is A
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2318) * and ->links_to is B. In this case, we can say the lock_list is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2319) * "B <- A" (bacwards case).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2320) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2321) * The ->trace of both a) and b) point to the call trace where B was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2322) * acquired with A held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2323) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2324) * 2) A "helper" lock_list is introduced during BFS, this lock_list doesn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2325) * represent a certain lock dependency, it only provides an initial entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2326) * for BFS. For example, BFS may introduce a "helper" lock_list whose
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2327) * ->class is A, as a result BFS will search all dependencies starting with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2328) * A, e.g. A -> B or A -> C.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2329) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2330) * The notation of a forwards helper lock_list is like "-> A", which means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2331) * we should search the forwards dependencies starting with "A", e.g A -> B
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2332) * or A -> C.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2333) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2334) * The notation of a bacwards helper lock_list is like "<- B", which means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2335) * we should search the backwards dependencies ending with "B", e.g.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2336) * B <- A or B <- C.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2337) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2339) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2340) * printk the shortest lock dependencies from @root to @leaf in reverse order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2341) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2342) * We have a lock dependency path as follow:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2343) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2344) * @root @leaf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2345) * | |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2346) * V V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2347) * ->parent ->parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2348) * | lock_list | <--------- | lock_list | ... | lock_list | <--------- | lock_list |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2349) * | -> L1 | | L1 -> L2 | ... |Ln-2 -> Ln-1| | Ln-1 -> Ln|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2350) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2351) * , so it's natural that we start from @leaf and print every ->class and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2352) * ->trace until we reach the @root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2353) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2354) static void __used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2355) print_shortest_lock_dependencies(struct lock_list *leaf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2356) struct lock_list *root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2357) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2358) struct lock_list *entry = leaf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2359) int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2361) /*compute depth from generated tree by BFS*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2362) depth = get_lock_depth(leaf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2364) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2365) print_lock_class_header(entry->class, depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2366) printk("%*s ... acquired at:\n", depth, "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2367) print_lock_trace(entry->trace, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2368) printk("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2370) if (depth == 0 && (entry != root)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2371) printk("lockdep:%s bad path found in chain graph\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2372) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2373) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2375) entry = get_lock_parent(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2376) depth--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2377) } while (entry && (depth >= 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2380) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2381) * printk the shortest lock dependencies from @leaf to @root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2382) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2383) * We have a lock dependency path (from a backwards search) as follow:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2384) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2385) * @leaf @root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2386) * | |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2387) * V V
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2388) * ->parent ->parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2389) * | lock_list | ---------> | lock_list | ... | lock_list | ---------> | lock_list |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2390) * | L2 <- L1 | | L3 <- L2 | ... | Ln <- Ln-1 | | <- Ln |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2391) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2392) * , so when we iterate from @leaf to @root, we actually print the lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2393) * dependency path L1 -> L2 -> .. -> Ln in the non-reverse order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2394) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2395) * Another thing to notice here is that ->class of L2 <- L1 is L1, while the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2396) * ->trace of L2 <- L1 is the call trace of L2, in fact we don't have the call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2397) * trace of L1 in the dependency path, which is alright, because most of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2398) * time we can figure out where L1 is held from the call trace of L2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2399) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2400) static void __used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2401) print_shortest_lock_dependencies_backwards(struct lock_list *leaf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2402) struct lock_list *root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2403) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2404) struct lock_list *entry = leaf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2405) const struct lock_trace *trace = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2406) int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2408) /*compute depth from generated tree by BFS*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2409) depth = get_lock_depth(leaf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2411) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2412) print_lock_class_header(entry->class, depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2413) if (trace) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2414) printk("%*s ... acquired at:\n", depth, "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2415) print_lock_trace(trace, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2416) printk("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2417) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2419) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2420) * Record the pointer to the trace for the next lock_list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2421) * entry, see the comments for the function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2422) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2423) trace = entry->trace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2425) if (depth == 0 && (entry != root)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2426) printk("lockdep:%s bad path found in chain graph\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2427) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2430) entry = get_lock_parent(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2431) depth--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2432) } while (entry && (depth >= 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2435) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2436) print_irq_lock_scenario(struct lock_list *safe_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2437) struct lock_list *unsafe_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2438) struct lock_class *prev_class,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2439) struct lock_class *next_class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2440) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2441) struct lock_class *safe_class = safe_entry->class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2442) struct lock_class *unsafe_class = unsafe_entry->class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2443) struct lock_class *middle_class = prev_class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2445) if (middle_class == safe_class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2446) middle_class = next_class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2447)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2448) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2449) * A direct locking problem where unsafe_class lock is taken
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2450) * directly by safe_class lock, then all we need to show
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2451) * is the deadlock scenario, as it is obvious that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2452) * unsafe lock is taken under the safe lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2453) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2454) * But if there is a chain instead, where the safe lock takes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2455) * an intermediate lock (middle_class) where this lock is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2456) * not the same as the safe lock, then the lock chain is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2457) * used to describe the problem. Otherwise we would need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2458) * to show a different CPU case for each link in the chain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2459) * from the safe_class lock to the unsafe_class lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2460) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2461) if (middle_class != unsafe_class) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2462) printk("Chain exists of:\n ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2463) __print_lock_name(safe_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2464) printk(KERN_CONT " --> ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2465) __print_lock_name(middle_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2466) printk(KERN_CONT " --> ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2467) __print_lock_name(unsafe_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2468) printk(KERN_CONT "\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2469) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2471) printk(" Possible interrupt unsafe locking scenario:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2472) printk(" CPU0 CPU1\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2473) printk(" ---- ----\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2474) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2475) __print_lock_name(unsafe_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2476) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2477) printk(" local_irq_disable();\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2478) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2479) __print_lock_name(safe_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2480) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2481) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2482) __print_lock_name(middle_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2483) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2484) printk(" <Interrupt>\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2485) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2486) __print_lock_name(safe_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2487) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2488) printk("\n *** DEADLOCK ***\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2489) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2491) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2492) print_bad_irq_dependency(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2493) struct lock_list *prev_root,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2494) struct lock_list *next_root,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2495) struct lock_list *backwards_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2496) struct lock_list *forwards_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2497) struct held_lock *prev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2498) struct held_lock *next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2499) enum lock_usage_bit bit1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2500) enum lock_usage_bit bit2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2501) const char *irqclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2502) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2503) if (!debug_locks_off_graph_unlock() || debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2504) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2506) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2507) pr_warn("=====================================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2508) pr_warn("WARNING: %s-safe -> %s-unsafe lock order detected\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2509) irqclass, irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2510) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2511) pr_warn("-----------------------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2512) pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2513) curr->comm, task_pid_nr(curr),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2514) lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2515) curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2516) lockdep_hardirqs_enabled(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2517) curr->softirqs_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2518) print_lock(next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2520) pr_warn("\nand this task is already holding:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2521) print_lock(prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2522) pr_warn("which would create a new lock dependency:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2523) print_lock_name(hlock_class(prev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2524) pr_cont(" ->");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2525) print_lock_name(hlock_class(next));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2526) pr_cont("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2527)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2528) pr_warn("\nbut this new dependency connects a %s-irq-safe lock:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2529) irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2530) print_lock_name(backwards_entry->class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2531) pr_warn("\n... which became %s-irq-safe at:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2533) print_lock_trace(backwards_entry->class->usage_traces[bit1], 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2535) pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2536) print_lock_name(forwards_entry->class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2537) pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2538) pr_warn("...");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2540) print_lock_trace(forwards_entry->class->usage_traces[bit2], 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2542) pr_warn("\nother info that might help us debug this:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2543) print_irq_lock_scenario(backwards_entry, forwards_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2544) hlock_class(prev), hlock_class(next));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2546) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2548) pr_warn("\nthe dependencies between %s-irq-safe lock and the holding lock:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2549) prev_root->trace = save_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2550) if (!prev_root->trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2551) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2552) print_shortest_lock_dependencies_backwards(backwards_entry, prev_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2554) pr_warn("\nthe dependencies between the lock to be acquired");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2555) pr_warn(" and %s-irq-unsafe lock:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2556) next_root->trace = save_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2557) if (!next_root->trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2558) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2559) print_shortest_lock_dependencies(forwards_entry, next_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2560)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2561) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2562) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2563) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2564)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2565) static const char *state_names[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2566) #define LOCKDEP_STATE(__STATE) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2567) __stringify(__STATE),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2568) #include "lockdep_states.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2569) #undef LOCKDEP_STATE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2570) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2571)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2572) static const char *state_rnames[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2573) #define LOCKDEP_STATE(__STATE) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2574) __stringify(__STATE)"-READ",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2575) #include "lockdep_states.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2576) #undef LOCKDEP_STATE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2577) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2579) static inline const char *state_name(enum lock_usage_bit bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2580) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2581) if (bit & LOCK_USAGE_READ_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2582) return state_rnames[bit >> LOCK_USAGE_DIR_MASK];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2583) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2584) return state_names[bit >> LOCK_USAGE_DIR_MASK];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2585) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2587) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2588) * The bit number is encoded like:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2589) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2590) * bit0: 0 exclusive, 1 read lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2591) * bit1: 0 used in irq, 1 irq enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2592) * bit2-n: state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2593) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2594) static int exclusive_bit(int new_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2595) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2596) int state = new_bit & LOCK_USAGE_STATE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2597) int dir = new_bit & LOCK_USAGE_DIR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2599) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2600) * keep state, bit flip the direction and strip read.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2601) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2602) return state | (dir ^ LOCK_USAGE_DIR_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2603) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2604)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2605) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2606) * Observe that when given a bitmask where each bitnr is encoded as above, a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2607) * right shift of the mask transforms the individual bitnrs as -1 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2608) * conversely, a left shift transforms into +1 for the individual bitnrs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2609) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2610) * So for all bits whose number have LOCK_ENABLED_* set (bitnr1 == 1), we can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2611) * create the mask with those bit numbers using LOCK_USED_IN_* (bitnr1 == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2612) * instead by subtracting the bit number by 2, or shifting the mask right by 2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2613) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2614) * Similarly, bitnr1 == 0 becomes bitnr1 == 1 by adding 2, or shifting left 2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2615) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2616) * So split the mask (note that LOCKF_ENABLED_IRQ_ALL|LOCKF_USED_IN_IRQ_ALL is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2617) * all bits set) and recompose with bitnr1 flipped.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2618) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2619) static unsigned long invert_dir_mask(unsigned long mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2620) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2621) unsigned long excl = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2623) /* Invert dir */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2624) excl |= (mask & LOCKF_ENABLED_IRQ_ALL) >> LOCK_USAGE_DIR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2625) excl |= (mask & LOCKF_USED_IN_IRQ_ALL) << LOCK_USAGE_DIR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2627) return excl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2628) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2629)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2630) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2631) * Note that a LOCK_ENABLED_IRQ_*_READ usage and a LOCK_USED_IN_IRQ_*_READ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2632) * usage may cause deadlock too, for example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2633) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2634) * P1 P2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2635) * <irq disabled>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2636) * write_lock(l1); <irq enabled>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2637) * read_lock(l2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2638) * write_lock(l2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2639) * <in irq>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2640) * read_lock(l1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2641) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2642) * , in above case, l1 will be marked as LOCK_USED_IN_IRQ_HARDIRQ_READ and l2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2643) * will marked as LOCK_ENABLE_IRQ_HARDIRQ_READ, and this is a possible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2644) * deadlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2645) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2646) * In fact, all of the following cases may cause deadlocks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2647) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2648) * LOCK_USED_IN_IRQ_* -> LOCK_ENABLED_IRQ_*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2649) * LOCK_USED_IN_IRQ_*_READ -> LOCK_ENABLED_IRQ_*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2650) * LOCK_USED_IN_IRQ_* -> LOCK_ENABLED_IRQ_*_READ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2651) * LOCK_USED_IN_IRQ_*_READ -> LOCK_ENABLED_IRQ_*_READ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2652) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2653) * As a result, to calculate the "exclusive mask", first we invert the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2654) * direction (USED_IN/ENABLED) of the original mask, and 1) for all bits with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2655) * bitnr0 set (LOCK_*_READ), add those with bitnr0 cleared (LOCK_*). 2) for all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2656) * bits with bitnr0 cleared (LOCK_*_READ), add those with bitnr0 set (LOCK_*).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2657) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2658) static unsigned long exclusive_mask(unsigned long mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2659) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2660) unsigned long excl = invert_dir_mask(mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2662) excl |= (excl & LOCKF_IRQ_READ) >> LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2663) excl |= (excl & LOCKF_IRQ) << LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2665) return excl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2666) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2667)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2668) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2669) * Retrieve the _possible_ original mask to which @mask is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2670) * exclusive. Ie: this is the opposite of exclusive_mask().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2671) * Note that 2 possible original bits can match an exclusive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2672) * bit: one has LOCK_USAGE_READ_MASK set, the other has it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2673) * cleared. So both are returned for each exclusive bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2674) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2675) static unsigned long original_mask(unsigned long mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2676) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2677) unsigned long excl = invert_dir_mask(mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2679) /* Include read in existing usages */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2680) excl |= (excl & LOCKF_IRQ_READ) >> LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2681) excl |= (excl & LOCKF_IRQ) << LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2683) return excl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2684) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2685)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2686) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2687) * Find the first pair of bit match between an original
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2688) * usage mask and an exclusive usage mask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2689) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2690) static int find_exclusive_match(unsigned long mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2691) unsigned long excl_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2692) enum lock_usage_bit *bitp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2693) enum lock_usage_bit *excl_bitp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2694) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2695) int bit, excl, excl_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2697) for_each_set_bit(bit, &mask, LOCK_USED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2698) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2699) * exclusive_bit() strips the read bit, however,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2700) * LOCK_ENABLED_IRQ_*_READ may cause deadlocks too, so we need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2701) * to search excl | LOCK_USAGE_READ_MASK as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2702) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2703) excl = exclusive_bit(bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2704) excl_read = excl | LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2705) if (excl_mask & lock_flag(excl)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2706) *bitp = bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2707) *excl_bitp = excl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2708) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2709) } else if (excl_mask & lock_flag(excl_read)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2710) *bitp = bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2711) *excl_bitp = excl_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2712) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2713) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2714) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2715) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2716) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2717)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2718) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2719) * Prove that the new dependency does not connect a hardirq-safe(-read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2720) * lock with a hardirq-unsafe lock - to achieve this we search
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2721) * the backwards-subgraph starting at <prev>, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2722) * forwards-subgraph starting at <next>:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2723) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2724) static int check_irq_usage(struct task_struct *curr, struct held_lock *prev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2725) struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2726) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2727) unsigned long usage_mask = 0, forward_mask, backward_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2728) enum lock_usage_bit forward_bit = 0, backward_bit = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2729) struct lock_list *target_entry1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2730) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2731) struct lock_list this, that;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2732) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2734) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2735) * Step 1: gather all hard/soft IRQs usages backward in an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2736) * accumulated usage mask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2737) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2738) bfs_init_rootb(&this, prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2740) ret = __bfs_backwards(&this, &usage_mask, usage_accumulate, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2741) if (bfs_error(ret)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2742) print_bfs_bug(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2743) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2744) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2746) usage_mask &= LOCKF_USED_IN_IRQ_ALL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2747) if (!usage_mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2748) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2750) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2751) * Step 2: find exclusive uses forward that match the previous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2752) * backward accumulated mask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2753) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2754) forward_mask = exclusive_mask(usage_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2756) bfs_init_root(&that, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2757)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2758) ret = find_usage_forwards(&that, forward_mask, &target_entry1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2759) if (bfs_error(ret)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2760) print_bfs_bug(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2761) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2762) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2763) if (ret == BFS_RNOMATCH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2764) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2766) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2767) * Step 3: we found a bad match! Now retrieve a lock from the backward
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2768) * list whose usage mask matches the exclusive usage mask from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2769) * lock found on the forward list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2770) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2771) * Note, we should only keep the LOCKF_ENABLED_IRQ_ALL bits, considering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2772) * the follow case:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2773) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2774) * When trying to add A -> B to the graph, we find that there is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2775) * hardirq-safe L, that L -> ... -> A, and another hardirq-unsafe M,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2776) * that B -> ... -> M. However M is **softirq-safe**, if we use exact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2777) * invert bits of M's usage_mask, we will find another lock N that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2778) * **softirq-unsafe** and N -> ... -> A, however N -> .. -> M will not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2779) * cause a inversion deadlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2780) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2781) backward_mask = original_mask(target_entry1->class->usage_mask & LOCKF_ENABLED_IRQ_ALL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2782)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2783) ret = find_usage_backwards(&this, backward_mask, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2784) if (bfs_error(ret)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2785) print_bfs_bug(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2786) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2787) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2788) if (DEBUG_LOCKS_WARN_ON(ret == BFS_RNOMATCH))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2789) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2790)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2791) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2792) * Step 4: narrow down to a pair of incompatible usage bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2793) * and report it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2794) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2795) ret = find_exclusive_match(target_entry->class->usage_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2796) target_entry1->class->usage_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2797) &backward_bit, &forward_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2798) if (DEBUG_LOCKS_WARN_ON(ret == -1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2799) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2801) print_bad_irq_dependency(curr, &this, &that,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2802) target_entry, target_entry1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2803) prev, next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2804) backward_bit, forward_bit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2805) state_name(backward_bit));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2806)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2807) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2808) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2810) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2812) static inline int check_irq_usage(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2813) struct held_lock *prev, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2814) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2815) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2816) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2817) #endif /* CONFIG_TRACE_IRQFLAGS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2819) static void inc_chains(int irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2820) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2821) if (irq_context & LOCK_CHAIN_HARDIRQ_CONTEXT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2822) nr_hardirq_chains++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2823) else if (irq_context & LOCK_CHAIN_SOFTIRQ_CONTEXT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2824) nr_softirq_chains++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2825) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2826) nr_process_chains++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2827) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2828)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2829) static void dec_chains(int irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2830) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2831) if (irq_context & LOCK_CHAIN_HARDIRQ_CONTEXT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2832) nr_hardirq_chains--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2833) else if (irq_context & LOCK_CHAIN_SOFTIRQ_CONTEXT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2834) nr_softirq_chains--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2835) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2836) nr_process_chains--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2837) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2838)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2839) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2840) print_deadlock_scenario(struct held_lock *nxt, struct held_lock *prv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2841) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2842) struct lock_class *next = hlock_class(nxt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2843) struct lock_class *prev = hlock_class(prv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2844)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2845) printk(" Possible unsafe locking scenario:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2846) printk(" CPU0\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2847) printk(" ----\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2848) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2849) __print_lock_name(prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2850) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2851) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2852) __print_lock_name(next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2853) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2854) printk("\n *** DEADLOCK ***\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2855) printk(" May be due to missing lock nesting notation\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2856) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2857)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2858) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2859) print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2860) struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2861) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2862) if (!debug_locks_off_graph_unlock() || debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2863) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2864)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2865) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2866) pr_warn("============================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2867) pr_warn("WARNING: possible recursive locking detected\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2868) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2869) pr_warn("--------------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2870) pr_warn("%s/%d is trying to acquire lock:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2871) curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2872) print_lock(next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2873) pr_warn("\nbut task is already holding lock:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2874) print_lock(prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2875)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2876) pr_warn("\nother info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2877) print_deadlock_scenario(next, prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2878) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2880) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2881) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2882) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2883)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2884) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2885) * Check whether we are holding such a class already.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2886) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2887) * (Note that this has to be done separately, because the graph cannot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2888) * detect such classes of deadlocks.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2889) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2890) * Returns: 0 on deadlock detected, 1 on OK, 2 if another lock with the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2891) * lock class is held but nest_lock is also held, i.e. we rely on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2892) * nest_lock to avoid the deadlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2893) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2894) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2895) check_deadlock(struct task_struct *curr, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2896) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2897) struct held_lock *prev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2898) struct held_lock *nest = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2899) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2901) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2902) prev = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2904) if (prev->instance == next->nest_lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2905) nest = prev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2906)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2907) if (hlock_class(prev) != hlock_class(next))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2908) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2910) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2911) * Allow read-after-read recursion of the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2912) * lock class (i.e. read_lock(lock)+read_lock(lock)):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2913) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2914) if ((next->read == 2) && prev->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2915) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2916)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2917) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2918) * We're holding the nest_lock, which serializes this lock's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2919) * nesting behaviour.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2920) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2921) if (nest)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2922) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2923)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2924) print_deadlock_bug(curr, prev, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2925) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2926) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2927) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2928) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2930) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2931) * There was a chain-cache miss, and we are about to add a new dependency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2932) * to a previous lock. We validate the following rules:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2933) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2934) * - would the adding of the <prev> -> <next> dependency create a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2935) * circular dependency in the graph? [== circular deadlock]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2936) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2937) * - does the new prev->next dependency connect any hardirq-safe lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2938) * (in the full backwards-subgraph starting at <prev>) with any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2939) * hardirq-unsafe lock (in the full forwards-subgraph starting at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2940) * <next>)? [== illegal lock inversion with hardirq contexts]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2941) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2942) * - does the new prev->next dependency connect any softirq-safe lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2943) * (in the full backwards-subgraph starting at <prev>) with any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2944) * softirq-unsafe lock (in the full forwards-subgraph starting at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2945) * <next>)? [== illegal lock inversion with softirq contexts]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2946) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2947) * any of these scenarios could lead to a deadlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2948) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2949) * Then if all the validations pass, we add the forwards and backwards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2950) * dependency.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2951) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2952) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2953) check_prev_add(struct task_struct *curr, struct held_lock *prev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2954) struct held_lock *next, u16 distance,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2955) struct lock_trace **const trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2956) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2957) struct lock_list *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2958) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2959)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2960) if (!hlock_class(prev)->key || !hlock_class(next)->key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2961) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2962) * The warning statements below may trigger a use-after-free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2963) * of the class name. It is better to trigger a use-after free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2964) * and to have the class name most of the time instead of not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2965) * having the class name available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2966) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2967) WARN_ONCE(!debug_locks_silent && !hlock_class(prev)->key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2968) "Detected use-after-free of lock class %px/%s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2969) hlock_class(prev),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2970) hlock_class(prev)->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2971) WARN_ONCE(!debug_locks_silent && !hlock_class(next)->key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2972) "Detected use-after-free of lock class %px/%s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2973) hlock_class(next),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2974) hlock_class(next)->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2975) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2976) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2977)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2978) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2979) * Prove that the new <prev> -> <next> dependency would not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2980) * create a circular dependency in the graph. (We do this by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2981) * a breadth-first search into the graph starting at <next>,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2982) * and check whether we can reach <prev>.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2983) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2984) * The search is limited by the size of the circular queue (i.e.,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2985) * MAX_CIRCULAR_QUEUE_SIZE) which keeps track of a breadth of nodes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2986) * in the graph whose neighbours are to be checked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2987) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2988) ret = check_noncircular(next, prev, trace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2989) if (unlikely(bfs_error(ret) || ret == BFS_RMATCH))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2990) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2992) if (!check_irq_usage(curr, prev, next))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2993) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2995) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2996) * Is the <prev> -> <next> dependency already present?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2997) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2998) * (this may occur even though this is a new chain: consider
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2999) * e.g. the L1 -> L2 -> L3 -> L4 and the L5 -> L1 -> L2 -> L3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3000) * chains - the second one will be new, but L1 already has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3001) * L2 added to its dependency list, due to the first chain.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3002) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3003) list_for_each_entry(entry, &hlock_class(prev)->locks_after, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3004) if (entry->class == hlock_class(next)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3005) if (distance == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3006) entry->distance = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3007) entry->dep |= calc_dep(prev, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3008)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3009) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3010) * Also, update the reverse dependency in @next's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3011) * ->locks_before list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3012) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3013) * Here we reuse @entry as the cursor, which is fine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3014) * because we won't go to the next iteration of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3015) * outer loop:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3016) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3017) * For normal cases, we return in the inner loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3018) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3019) * If we fail to return, we have inconsistency, i.e.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3020) * <prev>::locks_after contains <next> while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3021) * <next>::locks_before doesn't contain <prev>. In
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3022) * that case, we return after the inner and indicate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3023) * something is wrong.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3024) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3025) list_for_each_entry(entry, &hlock_class(next)->locks_before, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3026) if (entry->class == hlock_class(prev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3027) if (distance == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3028) entry->distance = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3029) entry->dep |= calc_depb(prev, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3030) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3031) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3032) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3033)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3034) /* <prev> is not found in <next>::locks_before */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3035) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3036) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3037) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3039) #ifdef CONFIG_LOCKDEP_SMALL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3040) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3041) * Is the <prev> -> <next> link redundant?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3042) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3043) ret = check_redundant(prev, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3044) if (bfs_error(ret))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3045) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3046) else if (ret == BFS_RMATCH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3047) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3048) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3049)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3050) if (!*trace) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3051) *trace = save_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3052) if (!*trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3053) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3054) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3055)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3056) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3057) * Ok, all validations passed, add the new lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3058) * to the previous lock's dependency list:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3059) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3060) ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3061) &hlock_class(prev)->locks_after,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3062) next->acquire_ip, distance,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3063) calc_dep(prev, next),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3064) *trace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3065)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3066) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3067) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3068)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3069) ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3070) &hlock_class(next)->locks_before,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3071) next->acquire_ip, distance,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3072) calc_depb(prev, next),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3073) *trace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3074) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3075) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3076)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3077) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3078) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3079)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3080) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3081) * Add the dependency to all directly-previous locks that are 'relevant'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3082) * The ones that are relevant are (in increasing distance from curr):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3083) * all consecutive trylock entries and the final non-trylock entry - or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3084) * the end of this context's lock-chain - whichever comes first.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3085) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3086) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3087) check_prevs_add(struct task_struct *curr, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3088) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3089) struct lock_trace *trace = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3090) int depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3091) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3092)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3093) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3094) * Debugging checks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3095) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3096) * Depth must not be zero for a non-head lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3097) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3098) if (!depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3099) goto out_bug;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3100) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3101) * At least two relevant locks must exist for this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3102) * to be a head:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3103) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3104) if (curr->held_locks[depth].irq_context !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3105) curr->held_locks[depth-1].irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3106) goto out_bug;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3108) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3109) u16 distance = curr->lockdep_depth - depth + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3110) hlock = curr->held_locks + depth - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3112) if (hlock->check) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3113) int ret = check_prev_add(curr, hlock, next, distance, &trace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3114) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3115) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3117) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3118) * Stop after the first non-trylock entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3119) * as non-trylock entries have added their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3120) * own direct dependencies already, so this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3121) * lock is connected to them indirectly:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3123) if (!hlock->trylock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3124) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3127) depth--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3128) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3129) * End of lock-stack?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3130) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3131) if (!depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3132) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3133) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3134) * Stop the search if we cross into another context:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3135) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3136) if (curr->held_locks[depth].irq_context !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3137) curr->held_locks[depth-1].irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3138) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3140) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3141) out_bug:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3142) if (!debug_locks_off_graph_unlock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3143) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3145) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3146) * Clearly we all shouldn't be here, but since we made it we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3147) * can reliable say we messed up our state. See the above two
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3148) * gotos for reasons why we could possibly end up here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3149) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3150) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3152) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3153) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3155) struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3156) static DECLARE_BITMAP(lock_chains_in_use, MAX_LOCKDEP_CHAINS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3157) static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3158) unsigned long nr_zapped_lock_chains;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3159) unsigned int nr_free_chain_hlocks; /* Free chain_hlocks in buckets */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3160) unsigned int nr_lost_chain_hlocks; /* Lost chain_hlocks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3161) unsigned int nr_large_chain_blocks; /* size > MAX_CHAIN_BUCKETS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3163) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3164) * The first 2 chain_hlocks entries in the chain block in the bucket
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3165) * list contains the following meta data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3166) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3167) * entry[0]:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3168) * Bit 15 - always set to 1 (it is not a class index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3169) * Bits 0-14 - upper 15 bits of the next block index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3170) * entry[1] - lower 16 bits of next block index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3171) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3172) * A next block index of all 1 bits means it is the end of the list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3173) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3174) * On the unsized bucket (bucket-0), the 3rd and 4th entries contain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3175) * the chain block size:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3176) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3177) * entry[2] - upper 16 bits of the chain block size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3178) * entry[3] - lower 16 bits of the chain block size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3179) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3180) #define MAX_CHAIN_BUCKETS 16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3181) #define CHAIN_BLK_FLAG (1U << 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3182) #define CHAIN_BLK_LIST_END 0xFFFFU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3184) static int chain_block_buckets[MAX_CHAIN_BUCKETS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3186) static inline int size_to_bucket(int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3187) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3188) if (size > MAX_CHAIN_BUCKETS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3189) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3191) return size - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3194) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3195) * Iterate all the chain blocks in a bucket.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3196) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3197) #define for_each_chain_block(bucket, prev, curr) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3198) for ((prev) = -1, (curr) = chain_block_buckets[bucket]; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3199) (curr) >= 0; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3200) (prev) = (curr), (curr) = chain_block_next(curr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3202) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3203) * next block or -1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3204) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3205) static inline int chain_block_next(int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3206) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3207) int next = chain_hlocks[offset];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3209) WARN_ON_ONCE(!(next & CHAIN_BLK_FLAG));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3211) if (next == CHAIN_BLK_LIST_END)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3212) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3214) next &= ~CHAIN_BLK_FLAG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3215) next <<= 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3216) next |= chain_hlocks[offset + 1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3218) return next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3219) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3221) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3222) * bucket-0 only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3223) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3224) static inline int chain_block_size(int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3226) return (chain_hlocks[offset + 2] << 16) | chain_hlocks[offset + 3];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3229) static inline void init_chain_block(int offset, int next, int bucket, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3230) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3231) chain_hlocks[offset] = (next >> 16) | CHAIN_BLK_FLAG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3232) chain_hlocks[offset + 1] = (u16)next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3234) if (size && !bucket) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3235) chain_hlocks[offset + 2] = size >> 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3236) chain_hlocks[offset + 3] = (u16)size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3240) static inline void add_chain_block(int offset, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3241) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3242) int bucket = size_to_bucket(size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3243) int next = chain_block_buckets[bucket];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3244) int prev, curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3246) if (unlikely(size < 2)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3247) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3248) * We can't store single entries on the freelist. Leak them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3249) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3250) * One possible way out would be to uniquely mark them, other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3251) * than with CHAIN_BLK_FLAG, such that we can recover them when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3252) * the block before it is re-added.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3253) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3254) if (size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3255) nr_lost_chain_hlocks++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3256) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3259) nr_free_chain_hlocks += size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3260) if (!bucket) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3261) nr_large_chain_blocks++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3263) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3264) * Variable sized, sort large to small.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3265) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3266) for_each_chain_block(0, prev, curr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3267) if (size >= chain_block_size(curr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3268) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3269) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3270) init_chain_block(offset, curr, 0, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3271) if (prev < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3272) chain_block_buckets[0] = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3273) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3274) init_chain_block(prev, offset, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3275) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3276) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3277) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3278) * Fixed size, add to head.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3279) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3280) init_chain_block(offset, next, bucket, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3281) chain_block_buckets[bucket] = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3282) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3284) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3285) * Only the first block in the list can be deleted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3286) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3287) * For the variable size bucket[0], the first block (the largest one) is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3288) * returned, broken up and put back into the pool. So if a chain block of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3289) * length > MAX_CHAIN_BUCKETS is ever used and zapped, it will just be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3290) * queued up after the primordial chain block and never be used until the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3291) * hlock entries in the primordial chain block is almost used up. That
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3292) * causes fragmentation and reduce allocation efficiency. That can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3293) * monitored by looking at the "large chain blocks" number in lockdep_stats.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3294) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3295) static inline void del_chain_block(int bucket, int size, int next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3296) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3297) nr_free_chain_hlocks -= size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3298) chain_block_buckets[bucket] = next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3300) if (!bucket)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3301) nr_large_chain_blocks--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3302) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3304) static void init_chain_block_buckets(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3305) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3306) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3308) for (i = 0; i < MAX_CHAIN_BUCKETS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3309) chain_block_buckets[i] = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3311) add_chain_block(0, ARRAY_SIZE(chain_hlocks));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3314) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3315) * Return offset of a chain block of the right size or -1 if not found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3316) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3317) * Fairly simple worst-fit allocator with the addition of a number of size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3318) * specific free lists.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3319) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3320) static int alloc_chain_hlocks(int req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3321) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3322) int bucket, curr, size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3324) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3325) * We rely on the MSB to act as an escape bit to denote freelist
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3326) * pointers. Make sure this bit isn't set in 'normal' class_idx usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3327) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3328) BUILD_BUG_ON((MAX_LOCKDEP_KEYS-1) & CHAIN_BLK_FLAG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3330) init_data_structures_once();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3332) if (nr_free_chain_hlocks < req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3333) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3335) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3336) * We require a minimum of 2 (u16) entries to encode a freelist
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3337) * 'pointer'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3338) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3339) req = max(req, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3340) bucket = size_to_bucket(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3341) curr = chain_block_buckets[bucket];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3343) if (bucket) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3344) if (curr >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3345) del_chain_block(bucket, req, chain_block_next(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3346) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3347) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3348) /* Try bucket 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3349) curr = chain_block_buckets[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3352) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3353) * The variable sized freelist is sorted by size; the first entry is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3354) * the largest. Use it if it fits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3355) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3356) if (curr >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3357) size = chain_block_size(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3358) if (likely(size >= req)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3359) del_chain_block(0, size, chain_block_next(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3360) add_chain_block(curr + req, size - req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3361) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3363) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3365) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3366) * Last resort, split a block in a larger sized bucket.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3367) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3368) for (size = MAX_CHAIN_BUCKETS; size > req; size--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3369) bucket = size_to_bucket(size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3370) curr = chain_block_buckets[bucket];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3371) if (curr < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3372) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3374) del_chain_block(bucket, size, chain_block_next(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3375) add_chain_block(curr + req, size - req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3376) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3377) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3379) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3382) static inline void free_chain_hlocks(int base, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3383) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3384) add_chain_block(base, max(size, 2));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3385) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3387) struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3388) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3389) u16 chain_hlock = chain_hlocks[chain->base + i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3390) unsigned int class_idx = chain_hlock_class_idx(chain_hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3392) return lock_classes + class_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3393) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3395) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3396) * Returns the index of the first held_lock of the current chain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3397) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3398) static inline int get_first_held_lock(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3399) struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3400) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3401) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3402) struct held_lock *hlock_curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3404) for (i = curr->lockdep_depth - 1; i >= 0; i--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3405) hlock_curr = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3406) if (hlock_curr->irq_context != hlock->irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3407) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3409) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3411) return ++i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3412) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3414) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3416) * Returns the next chain_key iteration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3417) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3418) static u64 print_chain_key_iteration(u16 hlock_id, u64 chain_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3419) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3420) u64 new_chain_key = iterate_chain_key(chain_key, hlock_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3421)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3422) printk(" hlock_id:%d -> chain_key:%016Lx",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3423) (unsigned int)hlock_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3424) (unsigned long long)new_chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3425) return new_chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3428) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3429) print_chain_keys_held_locks(struct task_struct *curr, struct held_lock *hlock_next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3430) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3431) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3432) u64 chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3433) int depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3434) int i = get_first_held_lock(curr, hlock_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3436) printk("depth: %u (irq_context %u)\n", depth - i + 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3437) hlock_next->irq_context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3438) for (; i < depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3439) hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3440) chain_key = print_chain_key_iteration(hlock_id(hlock), chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3442) print_lock(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3443) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3445) print_chain_key_iteration(hlock_id(hlock_next), chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3446) print_lock(hlock_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3449) static void print_chain_keys_chain(struct lock_chain *chain)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3450) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3451) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3452) u64 chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3453) u16 hlock_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3455) printk("depth: %u\n", chain->depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3456) for (i = 0; i < chain->depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3457) hlock_id = chain_hlocks[chain->base + i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3458) chain_key = print_chain_key_iteration(hlock_id, chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3460) print_lock_name(lock_classes + chain_hlock_class_idx(hlock_id));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3461) printk("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3462) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3463) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3464)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3465) static void print_collision(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3466) struct held_lock *hlock_next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3467) struct lock_chain *chain)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3468) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3469) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3470) pr_warn("============================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3471) pr_warn("WARNING: chain_key collision\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3472) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3473) pr_warn("----------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3474) pr_warn("%s/%d: ", current->comm, task_pid_nr(current));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3475) pr_warn("Hash chain already cached but the contents don't match!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3477) pr_warn("Held locks:");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3478) print_chain_keys_held_locks(curr, hlock_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3480) pr_warn("Locks in cached chain:");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3481) print_chain_keys_chain(chain);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3483) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3484) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3486) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3488) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3489) * Checks whether the chain and the current held locks are consistent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3490) * in depth and also in content. If they are not it most likely means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3491) * that there was a collision during the calculation of the chain_key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3492) * Returns: 0 not passed, 1 passed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3493) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3494) static int check_no_collision(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3495) struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3496) struct lock_chain *chain)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3497) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3498) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3499) int i, j, id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3501) i = get_first_held_lock(curr, hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3503) if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3504) print_collision(curr, hlock, chain);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3505) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3506) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3508) for (j = 0; j < chain->depth - 1; j++, i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3509) id = hlock_id(&curr->held_locks[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3511) if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3512) print_collision(curr, hlock, chain);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3513) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3514) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3515) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3516) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3517) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3518) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3519)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3520) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3521) * Given an index that is >= -1, return the index of the next lock chain.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3522) * Return -2 if there is no next lock chain.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3523) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3524) long lockdep_next_lockchain(long i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3525) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3526) i = find_next_bit(lock_chains_in_use, ARRAY_SIZE(lock_chains), i + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3527) return i < ARRAY_SIZE(lock_chains) ? i : -2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3528) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3530) unsigned long lock_chain_count(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3531) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3532) return bitmap_weight(lock_chains_in_use, ARRAY_SIZE(lock_chains));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3533) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3535) /* Must be called with the graph lock held. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3536) static struct lock_chain *alloc_lock_chain(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3537) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3538) int idx = find_first_zero_bit(lock_chains_in_use,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3539) ARRAY_SIZE(lock_chains));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3541) if (unlikely(idx >= ARRAY_SIZE(lock_chains)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3542) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3543) __set_bit(idx, lock_chains_in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3544) return lock_chains + idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3545) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3547) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3548) * Adds a dependency chain into chain hashtable. And must be called with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3549) * graph_lock held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3550) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3551) * Return 0 if fail, and graph_lock is released.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3552) * Return 1 if succeed, with graph_lock held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3553) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3554) static inline int add_chain_cache(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3555) struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3556) u64 chain_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3557) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3558) struct hlist_head *hash_head = chainhashentry(chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3559) struct lock_chain *chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3560) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3562) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3563) * The caller must hold the graph lock, ensure we've got IRQs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3564) * disabled to make this an IRQ-safe lock.. for recursion reasons
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3565) * lockdep won't complain about its own locking errors.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3566) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3567) if (lockdep_assert_locked())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3568) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3570) chain = alloc_lock_chain();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3571) if (!chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3572) if (!debug_locks_off_graph_unlock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3573) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3575) print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3576) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3577) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3578) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3579) chain->chain_key = chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3580) chain->irq_context = hlock->irq_context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3581) i = get_first_held_lock(curr, hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3582) chain->depth = curr->lockdep_depth + 1 - i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3583)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3584) BUILD_BUG_ON((1UL << 24) <= ARRAY_SIZE(chain_hlocks));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3585) BUILD_BUG_ON((1UL << 6) <= ARRAY_SIZE(curr->held_locks));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3586) BUILD_BUG_ON((1UL << 8*sizeof(chain_hlocks[0])) <= ARRAY_SIZE(lock_classes));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3588) j = alloc_chain_hlocks(chain->depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3589) if (j < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3590) if (!debug_locks_off_graph_unlock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3591) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3592)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3593) print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3594) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3595) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3596) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3598) chain->base = j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3599) for (j = 0; j < chain->depth - 1; j++, i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3600) int lock_id = hlock_id(curr->held_locks + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3602) chain_hlocks[chain->base + j] = lock_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3603) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3604) chain_hlocks[chain->base + j] = hlock_id(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3605) hlist_add_head_rcu(&chain->entry, hash_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3606) debug_atomic_inc(chain_lookup_misses);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3607) inc_chains(chain->irq_context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3609) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3610) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3612) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3613) * Look up a dependency chain. Must be called with either the graph lock or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3614) * the RCU read lock held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3615) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3616) static inline struct lock_chain *lookup_chain_cache(u64 chain_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3617) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3618) struct hlist_head *hash_head = chainhashentry(chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3619) struct lock_chain *chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3621) hlist_for_each_entry_rcu(chain, hash_head, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3622) if (READ_ONCE(chain->chain_key) == chain_key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3623) debug_atomic_inc(chain_lookup_hits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3624) return chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3625) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3626) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3627) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3628) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3629)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3630) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3631) * If the key is not present yet in dependency chain cache then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3632) * add it and return 1 - in this case the new dependency chain is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3633) * validated. If the key is already hashed, return 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3634) * (On return with 1 graph_lock is held.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3635) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3636) static inline int lookup_chain_cache_add(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3637) struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3638) u64 chain_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3639) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3640) struct lock_class *class = hlock_class(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3641) struct lock_chain *chain = lookup_chain_cache(chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3642)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3643) if (chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3644) cache_hit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3645) if (!check_no_collision(curr, hlock, chain))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3646) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3648) if (very_verbose(class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3649) printk("\nhash chain already cached, key: "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3650) "%016Lx tail class: [%px] %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3651) (unsigned long long)chain_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3652) class->key, class->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3653) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3655) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3656) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3658) if (very_verbose(class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3659) printk("\nnew hash chain, key: %016Lx tail class: [%px] %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3660) (unsigned long long)chain_key, class->key, class->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3661) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3662)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3663) if (!graph_lock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3664) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3666) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3667) * We have to walk the chain again locked - to avoid duplicates:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3668) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3669) chain = lookup_chain_cache(chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3670) if (chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3671) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3672) goto cache_hit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3673) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3675) if (!add_chain_cache(curr, hlock, chain_key))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3676) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3677)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3678) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3679) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3680)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3681) static int validate_chain(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3682) struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3683) int chain_head, u64 chain_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3684) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3685) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3686) * Trylock needs to maintain the stack of held locks, but it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3687) * does not add new dependencies, because trylock can be done
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3688) * in any order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3689) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3690) * We look up the chain_key and do the O(N^2) check and update of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3691) * the dependencies only if this is a new dependency chain.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3692) * (If lookup_chain_cache_add() return with 1 it acquires
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3693) * graph_lock for us)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3694) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3695) if (!hlock->trylock && hlock->check &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3696) lookup_chain_cache_add(curr, hlock, chain_key)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3697) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3698) * Check whether last held lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3699) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3700) * - is irq-safe, if this lock is irq-unsafe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3701) * - is softirq-safe, if this lock is hardirq-unsafe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3702) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3703) * And check whether the new lock's dependency graph
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3704) * could lead back to the previous lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3705) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3706) * - within the current held-lock stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3707) * - across our accumulated lock dependency records
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3708) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3709) * any of these scenarios could lead to a deadlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3710) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3711) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3712) * The simple case: does the current hold the same lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3713) * already?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3714) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3715) int ret = check_deadlock(curr, hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3717) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3718) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3719) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3720) * Add dependency only if this lock is not the head
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3721) * of the chain, and if the new lock introduces no more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3722) * lock dependency (because we already hold a lock with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3723) * same lock class) nor deadlock (because the nest_lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3724) * serializes nesting locks), see the comments for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3725) * check_deadlock().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3726) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3727) if (!chain_head && ret != 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3728) if (!check_prevs_add(curr, hlock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3729) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3730) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3731)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3732) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3733) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3734) /* after lookup_chain_cache_add(): */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3735) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3736) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3737) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3738)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3739) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3740) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3741) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3742) static inline int validate_chain(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3743) struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3744) int chain_head, u64 chain_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3745) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3746) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3747) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3748)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3749) static void init_chain_block_buckets(void) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3750) #endif /* CONFIG_PROVE_LOCKING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3752) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3753) * We are building curr_chain_key incrementally, so double-check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3754) * it from scratch, to make sure that it's done correctly:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3755) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3756) static void check_chain_key(struct task_struct *curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3757) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3758) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3759) struct held_lock *hlock, *prev_hlock = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3760) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3761) u64 chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3763) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3764) hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3765) if (chain_key != hlock->prev_chain_key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3766) debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3767) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3768) * We got mighty confused, our chain keys don't match
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3769) * with what we expect, someone trample on our task state?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3770) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3771) WARN(1, "hm#1, depth: %u [%u], %016Lx != %016Lx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3772) curr->lockdep_depth, i,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3773) (unsigned long long)chain_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3774) (unsigned long long)hlock->prev_chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3775) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3776) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3778) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3779) * hlock->class_idx can't go beyond MAX_LOCKDEP_KEYS, but is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3780) * it registered lock class index?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3781) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3782) if (DEBUG_LOCKS_WARN_ON(!test_bit(hlock->class_idx, lock_classes_in_use)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3783) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3784)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3785) if (prev_hlock && (prev_hlock->irq_context !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3786) hlock->irq_context))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3787) chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3788) chain_key = iterate_chain_key(chain_key, hlock_id(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3789) prev_hlock = hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3790) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3791) if (chain_key != curr->curr_chain_key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3792) debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3793) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3794) * More smoking hash instead of calculating it, damn see these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3795) * numbers float.. I bet that a pink elephant stepped on my memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3796) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3797) WARN(1, "hm#2, depth: %u [%u], %016Lx != %016Lx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3798) curr->lockdep_depth, i,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3799) (unsigned long long)chain_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3800) (unsigned long long)curr->curr_chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3801) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3802) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3803) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3805) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3806) static int mark_lock(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3807) enum lock_usage_bit new_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3809) static void print_usage_bug_scenario(struct held_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3810) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3811) struct lock_class *class = hlock_class(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3812)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3813) printk(" Possible unsafe locking scenario:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3814) printk(" CPU0\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3815) printk(" ----\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3816) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3817) __print_lock_name(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3818) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3819) printk(" <Interrupt>\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3820) printk(" lock(");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3821) __print_lock_name(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3822) printk(KERN_CONT ");\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3823) printk("\n *** DEADLOCK ***\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3824) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3825)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3826) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3827) print_usage_bug(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3828) enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3829) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3830) if (!debug_locks_off() || debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3831) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3832)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3833) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3834) pr_warn("================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3835) pr_warn("WARNING: inconsistent lock state\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3836) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3837) pr_warn("--------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3838)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3839) pr_warn("inconsistent {%s} -> {%s} usage.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3840) usage_str[prev_bit], usage_str[new_bit]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3841)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3842) pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3843) curr->comm, task_pid_nr(curr),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3844) lockdep_hardirq_context(), hardirq_count() >> HARDIRQ_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3845) lockdep_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3846) lockdep_hardirqs_enabled(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3847) lockdep_softirqs_enabled(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3848) print_lock(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3850) pr_warn("{%s} state was registered at:\n", usage_str[prev_bit]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3851) print_lock_trace(hlock_class(this)->usage_traces[prev_bit], 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3852)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3853) print_irqtrace_events(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3854) pr_warn("\nother info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3855) print_usage_bug_scenario(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3856)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3857) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3858)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3859) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3860) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3861) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3862)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3863) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3864) * Print out an error if an invalid bit is set:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3865) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3866) static inline int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3867) valid_state(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3868) enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3869) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3870) if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3871) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3872) print_usage_bug(curr, this, bad_bit, new_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3873) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3874) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3875) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3876) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3877)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3878)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3879) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3880) * print irq inversion bug:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3881) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3882) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3883) print_irq_inversion_bug(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3884) struct lock_list *root, struct lock_list *other,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3885) struct held_lock *this, int forwards,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3886) const char *irqclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3887) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3888) struct lock_list *entry = other;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3889) struct lock_list *middle = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3890) int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3891)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3892) if (!debug_locks_off_graph_unlock() || debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3893) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3894)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3895) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3896) pr_warn("========================================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3897) pr_warn("WARNING: possible irq lock inversion dependency detected\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3898) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3899) pr_warn("--------------------------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3900) pr_warn("%s/%d just changed the state of lock:\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3901) curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3902) print_lock(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3903) if (forwards)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3904) pr_warn("but this lock took another, %s-unsafe lock in the past:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3905) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3906) pr_warn("but this lock was taken by another, %s-safe lock in the past:\n", irqclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3907) print_lock_name(other->class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3908) pr_warn("\n\nand interrupts could create inverse lock ordering between them.\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3910) pr_warn("\nother info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3911)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3912) /* Find a middle lock (if one exists) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3913) depth = get_lock_depth(other);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3914) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3915) if (depth == 0 && (entry != root)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3916) pr_warn("lockdep:%s bad path found in chain graph\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3917) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3918) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3919) middle = entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3920) entry = get_lock_parent(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3921) depth--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3922) } while (entry && entry != root && (depth >= 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3923) if (forwards)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3924) print_irq_lock_scenario(root, other,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3925) middle ? middle->class : root->class, other->class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3926) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3927) print_irq_lock_scenario(other, root,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3928) middle ? middle->class : other->class, root->class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3930) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3931)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3932) pr_warn("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3933) root->trace = save_trace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3934) if (!root->trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3935) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3936) print_shortest_lock_dependencies(other, root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3938) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3939) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3940) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3941)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3942) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3943) * Prove that in the forwards-direction subgraph starting at <this>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3944) * there is no lock matching <mask>:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3945) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3946) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3947) check_usage_forwards(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3948) enum lock_usage_bit bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3949) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3950) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3951) struct lock_list root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3952) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3953) enum lock_usage_bit read_bit = bit + LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3954) unsigned usage_mask = lock_flag(bit) | lock_flag(read_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3956) bfs_init_root(&root, this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3957) ret = find_usage_forwards(&root, usage_mask, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3958) if (bfs_error(ret)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3959) print_bfs_bug(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3960) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3961) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3962) if (ret == BFS_RNOMATCH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3963) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3965) /* Check whether write or read usage is the match */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3966) if (target_entry->class->usage_mask & lock_flag(bit)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3967) print_irq_inversion_bug(curr, &root, target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3968) this, 1, state_name(bit));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3969) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3970) print_irq_inversion_bug(curr, &root, target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3971) this, 1, state_name(read_bit));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3972) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3973)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3974) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3975) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3976)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3977) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3978) * Prove that in the backwards-direction subgraph starting at <this>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3979) * there is no lock matching <mask>:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3980) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3981) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3982) check_usage_backwards(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3983) enum lock_usage_bit bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3984) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3985) enum bfs_result ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3986) struct lock_list root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3987) struct lock_list *target_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3988) enum lock_usage_bit read_bit = bit + LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3989) unsigned usage_mask = lock_flag(bit) | lock_flag(read_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3990)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3991) bfs_init_rootb(&root, this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3992) ret = find_usage_backwards(&root, usage_mask, &target_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3993) if (bfs_error(ret)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3994) print_bfs_bug(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3995) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3996) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3997) if (ret == BFS_RNOMATCH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3998) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3999)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4000) /* Check whether write or read usage is the match */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4001) if (target_entry->class->usage_mask & lock_flag(bit)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4002) print_irq_inversion_bug(curr, &root, target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4003) this, 0, state_name(bit));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4004) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4005) print_irq_inversion_bug(curr, &root, target_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4006) this, 0, state_name(read_bit));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4007) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4008)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4009) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4010) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4011)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4012) void print_irqtrace_events(struct task_struct *curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4013) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4014) const struct irqtrace_events *trace = &curr->irqtrace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4015)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4016) printk("irq event stamp: %u\n", trace->irq_events);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4017) printk("hardirqs last enabled at (%u): [<%px>] %pS\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4018) trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4019) (void *)trace->hardirq_enable_ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4020) printk("hardirqs last disabled at (%u): [<%px>] %pS\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4021) trace->hardirq_disable_event, (void *)trace->hardirq_disable_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4022) (void *)trace->hardirq_disable_ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4023) printk("softirqs last enabled at (%u): [<%px>] %pS\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4024) trace->softirq_enable_event, (void *)trace->softirq_enable_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4025) (void *)trace->softirq_enable_ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4026) printk("softirqs last disabled at (%u): [<%px>] %pS\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4027) trace->softirq_disable_event, (void *)trace->softirq_disable_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4028) (void *)trace->softirq_disable_ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4029) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4030)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4031) static int HARDIRQ_verbose(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4032) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4033) #if HARDIRQ_VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4034) return class_filter(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4035) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4036) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4037) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4039) static int SOFTIRQ_verbose(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4040) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4041) #if SOFTIRQ_VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4042) return class_filter(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4043) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4044) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4045) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4046)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4047) static int (*state_verbose_f[])(struct lock_class *class) = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4048) #define LOCKDEP_STATE(__STATE) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4049) __STATE##_verbose,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4050) #include "lockdep_states.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4051) #undef LOCKDEP_STATE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4052) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4054) static inline int state_verbose(enum lock_usage_bit bit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4055) struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4056) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4057) return state_verbose_f[bit >> LOCK_USAGE_DIR_MASK](class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4058) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4059)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4060) typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4061) enum lock_usage_bit bit, const char *name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4062)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4063) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4064) mark_lock_irq(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4065) enum lock_usage_bit new_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4066) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4067) int excl_bit = exclusive_bit(new_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4068) int read = new_bit & LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4069) int dir = new_bit & LOCK_USAGE_DIR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4070)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4071) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4072) * Validate that this particular lock does not have conflicting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4073) * usage states.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4074) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4075) if (!valid_state(curr, this, new_bit, excl_bit))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4076) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4077)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4078) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4079) * Check for read in write conflicts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4080) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4081) if (!read && !valid_state(curr, this, new_bit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4082) excl_bit + LOCK_USAGE_READ_MASK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4083) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4084)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4085)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4086) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4087) * Validate that the lock dependencies don't have conflicting usage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4088) * states.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4089) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4090) if (dir) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4091) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4092) * mark ENABLED has to look backwards -- to ensure no dependee
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4093) * has USED_IN state, which, again, would allow recursion deadlocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4094) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4095) if (!check_usage_backwards(curr, this, excl_bit))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4096) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4097) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4098) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4099) * mark USED_IN has to look forwards -- to ensure no dependency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4100) * has ENABLED state, which would allow recursion deadlocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4101) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4102) if (!check_usage_forwards(curr, this, excl_bit))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4103) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4106) if (state_verbose(new_bit, hlock_class(this)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4107) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4109) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4112) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4113) * Mark all held locks with a usage bit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4114) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4115) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4116) mark_held_locks(struct task_struct *curr, enum lock_usage_bit base_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4118) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4119) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4121) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4122) enum lock_usage_bit hlock_bit = base_bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4123) hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4125) if (hlock->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4126) hlock_bit += LOCK_USAGE_READ_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4128) BUG_ON(hlock_bit >= LOCK_USAGE_STATES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4130) if (!hlock->check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4131) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4133) if (!mark_lock(curr, hlock, hlock_bit))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4134) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4137) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4140) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4141) * Hardirqs will be enabled:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4142) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4143) static void __trace_hardirqs_on_caller(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4144) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4145) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4147) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4148) * We are going to turn hardirqs on, so set the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4149) * usage bit for all held locks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4150) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4151) if (!mark_held_locks(curr, LOCK_ENABLED_HARDIRQ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4152) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4153) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4154) * If we have softirqs enabled, then set the usage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4155) * bit for all held locks. (disabled hardirqs prevented
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4156) * this bit from being set before)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4157) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4158) if (curr->softirqs_enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4159) mark_held_locks(curr, LOCK_ENABLED_SOFTIRQ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4162) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4163) * lockdep_hardirqs_on_prepare - Prepare for enabling interrupts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4164) * @ip: Caller address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4165) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4166) * Invoked before a possible transition to RCU idle from exit to user or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4167) * guest mode. This ensures that all RCU operations are done before RCU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4168) * stops watching. After the RCU transition lockdep_hardirqs_on() has to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4169) * invoked to set the final state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4170) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4171) void lockdep_hardirqs_on_prepare(unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4172) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4173) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4174) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4176) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4177) * NMIs do not (and cannot) track lock dependencies, nothing to do.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4178) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4179) if (unlikely(in_nmi()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4180) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4182) if (unlikely(this_cpu_read(lockdep_recursion)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4183) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4185) if (unlikely(lockdep_hardirqs_enabled())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4186) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4187) * Neither irq nor preemption are disabled here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4188) * so this is racy by nature but losing one hit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4189) * in a stat is not a big deal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4190) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4191) __debug_atomic_inc(redundant_hardirqs_on);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4192) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4193) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4195) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4196) * We're enabling irqs and according to our state above irqs weren't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4197) * already enabled, yet we find the hardware thinks they are in fact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4198) * enabled.. someone messed up their IRQ state tracing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4199) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4200) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4201) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4203) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4204) * See the fine text that goes along with this variable definition.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4205) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4206) if (DEBUG_LOCKS_WARN_ON(early_boot_irqs_disabled))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4207) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4209) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4210) * Can't allow enabling interrupts while in an interrupt handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4211) * that's general bad form and such. Recursion, limited stack etc..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4212) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4213) if (DEBUG_LOCKS_WARN_ON(lockdep_hardirq_context()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4214) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4216) current->hardirq_chain_key = current->curr_chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4218) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4219) __trace_hardirqs_on_caller();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4220) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4222) EXPORT_SYMBOL_GPL(lockdep_hardirqs_on_prepare);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4224) void noinstr lockdep_hardirqs_on(unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4226) struct irqtrace_events *trace = ¤t->irqtrace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4228) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4229) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4231) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4232) * NMIs can happen in the middle of local_irq_{en,dis}able() where the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4233) * tracking state and hardware state are out of sync.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4234) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4235) * NMIs must save lockdep_hardirqs_enabled() to restore IRQ state from,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4236) * and not rely on hardware state like normal interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4237) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4238) if (unlikely(in_nmi())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4239) if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4240) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4242) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4243) * Skip:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4244) * - recursion check, because NMI can hit lockdep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4245) * - hardware state check, because above;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4246) * - chain_key check, see lockdep_hardirqs_on_prepare().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4247) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4248) goto skip_checks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4251) if (unlikely(this_cpu_read(lockdep_recursion)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4252) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4254) if (lockdep_hardirqs_enabled()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4255) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4256) * Neither irq nor preemption are disabled here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4257) * so this is racy by nature but losing one hit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4258) * in a stat is not a big deal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4259) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4260) __debug_atomic_inc(redundant_hardirqs_on);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4261) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4264) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4265) * We're enabling irqs and according to our state above irqs weren't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4266) * already enabled, yet we find the hardware thinks they are in fact
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4267) * enabled.. someone messed up their IRQ state tracing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4268) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4269) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4270) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4272) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4273) * Ensure the lock stack remained unchanged between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4274) * lockdep_hardirqs_on_prepare() and lockdep_hardirqs_on().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4275) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4276) DEBUG_LOCKS_WARN_ON(current->hardirq_chain_key !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4277) current->curr_chain_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4279) skip_checks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4280) /* we'll do an OFF -> ON transition: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4281) __this_cpu_write(hardirqs_enabled, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4282) trace->hardirq_enable_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4283) trace->hardirq_enable_event = ++trace->irq_events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4284) debug_atomic_inc(hardirqs_on_events);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4285) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4286) EXPORT_SYMBOL_GPL(lockdep_hardirqs_on);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4288) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4289) * Hardirqs were disabled:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4290) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4291) void noinstr lockdep_hardirqs_off(unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4292) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4293) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4294) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4296) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4297) * Matching lockdep_hardirqs_on(), allow NMIs in the middle of lockdep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4298) * they will restore the software state. This ensures the software
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4299) * state is consistent inside NMIs as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4300) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4301) if (in_nmi()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4302) if (!IS_ENABLED(CONFIG_TRACE_IRQFLAGS_NMI))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4303) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4304) } else if (__this_cpu_read(lockdep_recursion))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4305) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4307) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4308) * So we're supposed to get called after you mask local IRQs, but for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4309) * some reason the hardware doesn't quite think you did a proper job.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4310) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4311) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4312) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4314) if (lockdep_hardirqs_enabled()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4315) struct irqtrace_events *trace = ¤t->irqtrace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4317) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4318) * We have done an ON -> OFF transition:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4319) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4320) __this_cpu_write(hardirqs_enabled, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4321) trace->hardirq_disable_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4322) trace->hardirq_disable_event = ++trace->irq_events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4323) debug_atomic_inc(hardirqs_off_events);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4324) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4325) debug_atomic_inc(redundant_hardirqs_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4327) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4328) EXPORT_SYMBOL_GPL(lockdep_hardirqs_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4330) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4331) * Softirqs will be enabled:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4332) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4333) void lockdep_softirqs_on(unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4334) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4335) struct irqtrace_events *trace = ¤t->irqtrace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4337) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4338) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4340) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4341) * We fancy IRQs being disabled here, see softirq.c, avoids
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4342) * funny state and nesting things.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4343) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4344) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4345) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4347) if (current->softirqs_enabled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4348) debug_atomic_inc(redundant_softirqs_on);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4349) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4352) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4353) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4354) * We'll do an OFF -> ON transition:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4355) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4356) current->softirqs_enabled = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4357) trace->softirq_enable_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4358) trace->softirq_enable_event = ++trace->irq_events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4359) debug_atomic_inc(softirqs_on_events);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4360) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4361) * We are going to turn softirqs on, so set the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4362) * usage bit for all held locks, if hardirqs are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4363) * enabled too:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4364) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4365) if (lockdep_hardirqs_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4366) mark_held_locks(current, LOCK_ENABLED_SOFTIRQ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4367) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4370) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4371) * Softirqs were disabled:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4372) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4373) void lockdep_softirqs_off(unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4374) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4375) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4376) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4378) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4379) * We fancy IRQs being disabled here, see softirq.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4380) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4381) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4382) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4384) if (current->softirqs_enabled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4385) struct irqtrace_events *trace = ¤t->irqtrace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4387) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4388) * We have done an ON -> OFF transition:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4389) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4390) current->softirqs_enabled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4391) trace->softirq_disable_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4392) trace->softirq_disable_event = ++trace->irq_events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4393) debug_atomic_inc(softirqs_off_events);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4394) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4395) * Whoops, we wanted softirqs off, so why aren't they?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4396) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4397) DEBUG_LOCKS_WARN_ON(!softirq_count());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4398) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4399) debug_atomic_inc(redundant_softirqs_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4400) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4402) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4403) mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4404) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4405) if (!check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4406) goto lock_used;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4408) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4409) * If non-trylock use in a hardirq or softirq context, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4410) * mark the lock as used in these contexts:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4411) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4412) if (!hlock->trylock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4413) if (hlock->read) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4414) if (lockdep_hardirq_context())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4415) if (!mark_lock(curr, hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4416) LOCK_USED_IN_HARDIRQ_READ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4417) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4418) if (curr->softirq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4419) if (!mark_lock(curr, hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4420) LOCK_USED_IN_SOFTIRQ_READ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4421) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4422) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4423) if (lockdep_hardirq_context())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4424) if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4425) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4426) if (curr->softirq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4427) if (!mark_lock(curr, hlock, LOCK_USED_IN_SOFTIRQ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4428) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4429) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4431) if (!hlock->hardirqs_off) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4432) if (hlock->read) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4433) if (!mark_lock(curr, hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4434) LOCK_ENABLED_HARDIRQ_READ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4435) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4436) if (curr->softirqs_enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4437) if (!mark_lock(curr, hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4438) LOCK_ENABLED_SOFTIRQ_READ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4439) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4440) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4441) if (!mark_lock(curr, hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4442) LOCK_ENABLED_HARDIRQ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4443) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4444) if (curr->softirqs_enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4445) if (!mark_lock(curr, hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4446) LOCK_ENABLED_SOFTIRQ))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4447) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4448) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4449) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4450)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4451) lock_used:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4452) /* mark it as used: */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4453) if (!mark_lock(curr, hlock, LOCK_USED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4454) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4456) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4457) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4459) static inline unsigned int task_irq_context(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4460) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4461) return LOCK_CHAIN_HARDIRQ_CONTEXT * !!lockdep_hardirq_context() +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4462) LOCK_CHAIN_SOFTIRQ_CONTEXT * !!task->softirq_context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4463) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4464)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4465) static int separate_irq_context(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4466) struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4467) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4468) unsigned int depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4470) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4471) * Keep track of points where we cross into an interrupt context:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4472) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4473) if (depth) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4474) struct held_lock *prev_hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4476) prev_hlock = curr->held_locks + depth-1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4477) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4478) * If we cross into another context, reset the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4479) * hash key (this also prevents the checking and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4480) * adding of the dependency to 'prev'):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4481) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4482) if (prev_hlock->irq_context != hlock->irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4483) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4484) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4485) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4486) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4488) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4489) * Mark a lock with a usage bit, and validate the state transition:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4490) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4491) static int mark_lock(struct task_struct *curr, struct held_lock *this,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4492) enum lock_usage_bit new_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4493) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4494) unsigned int new_mask, ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4496) if (new_bit >= LOCK_USAGE_STATES) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4497) DEBUG_LOCKS_WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4498) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4499) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4501) if (new_bit == LOCK_USED && this->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4502) new_bit = LOCK_USED_READ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4504) new_mask = 1 << new_bit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4506) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4507) * If already set then do not dirty the cacheline,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4508) * nor do any checks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4509) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4510) if (likely(hlock_class(this)->usage_mask & new_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4511) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4513) if (!graph_lock())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4514) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4515) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4516) * Make sure we didn't race:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4517) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4518) if (unlikely(hlock_class(this)->usage_mask & new_mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4519) goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4520)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4521) if (!hlock_class(this)->usage_mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4522) debug_atomic_dec(nr_unused_locks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4524) hlock_class(this)->usage_mask |= new_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4526) if (new_bit < LOCK_TRACE_STATES) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4527) if (!(hlock_class(this)->usage_traces[new_bit] = save_trace()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4528) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4529) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4531) if (new_bit < LOCK_USED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4532) ret = mark_lock_irq(curr, this, new_bit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4533) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4534) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4535) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4537) unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4538) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4540) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4541) * We must printk outside of the graph_lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4542) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4543) if (ret == 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4544) printk("\nmarked lock as {%s}:\n", usage_str[new_bit]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4545) print_lock(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4546) print_irqtrace_events(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4547) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4548) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4550) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4551) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4553) static inline short task_wait_context(struct task_struct *curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4554) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4555) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4556) * Set appropriate wait type for the context; for IRQs we have to take
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4557) * into account force_irqthread as that is implied by PREEMPT_RT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4558) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4559) if (lockdep_hardirq_context()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4560) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4561) * Check if force_irqthreads will run us threaded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4562) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4563) if (curr->hardirq_threaded || curr->irq_config)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4564) return LD_WAIT_CONFIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4565)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4566) return LD_WAIT_SPIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4567) } else if (curr->softirq_context) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4568) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4569) * Softirqs are always threaded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4570) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4571) return LD_WAIT_CONFIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4572) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4574) return LD_WAIT_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4575) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4577) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4578) print_lock_invalid_wait_context(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4579) struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4580) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4581) short curr_inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4583) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4584) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4585) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4586) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4588) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4589) pr_warn("=============================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4590) pr_warn("[ BUG: Invalid wait context ]\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4591) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4592) pr_warn("-----------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4594) pr_warn("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4595) print_lock(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4596)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4597) pr_warn("other info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4599) curr_inner = task_wait_context(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4600) pr_warn("context-{%d:%d}\n", curr_inner, curr_inner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4602) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4603)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4604) pr_warn("stack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4605) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4607) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4608) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4609)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4610) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4611) * Verify the wait_type context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4612) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4613) * This check validates we takes locks in the right wait-type order; that is it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4614) * ensures that we do not take mutexes inside spinlocks and do not attempt to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4615) * acquire spinlocks inside raw_spinlocks and the sort.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4616) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4617) * The entire thing is slightly more complex because of RCU, RCU is a lock that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4618) * can be taken from (pretty much) any context but also has constraints.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4619) * However when taken in a stricter environment the RCU lock does not loosen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4620) * the constraints.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4621) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4622) * Therefore we must look for the strictest environment in the lock stack and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4623) * compare that to the lock we're trying to acquire.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4624) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4625) static int check_wait_context(struct task_struct *curr, struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4626) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4627) u8 next_inner = hlock_class(next)->wait_type_inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4628) u8 next_outer = hlock_class(next)->wait_type_outer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4629) u8 curr_inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4630) int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4631)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4632) if (!next_inner || next->trylock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4633) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4635) if (!next_outer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4636) next_outer = next_inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4637)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4638) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4639) * Find start of current irq_context..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4640) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4641) for (depth = curr->lockdep_depth - 1; depth >= 0; depth--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4642) struct held_lock *prev = curr->held_locks + depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4643) if (prev->irq_context != next->irq_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4644) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4645) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4646) depth++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4648) curr_inner = task_wait_context(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4650) for (; depth < curr->lockdep_depth; depth++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4651) struct held_lock *prev = curr->held_locks + depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4652) u8 prev_inner = hlock_class(prev)->wait_type_inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4653)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4654) if (prev_inner) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4655) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4656) * We can have a bigger inner than a previous one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4657) * when outer is smaller than inner, as with RCU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4658) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4659) * Also due to trylocks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4660) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4661) curr_inner = min(curr_inner, prev_inner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4662) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4663) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4664)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4665) if (next_outer > curr_inner)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4666) return print_lock_invalid_wait_context(curr, next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4667)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4668) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4669) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4670)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4671) #else /* CONFIG_PROVE_LOCKING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4673) static inline int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4674) mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4675) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4676) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4677) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4678)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4679) static inline unsigned int task_irq_context(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4680) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4681) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4682) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4684) static inline int separate_irq_context(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4685) struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4686) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4687) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4688) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4689)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4690) static inline int check_wait_context(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4691) struct held_lock *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4692) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4693) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4694) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4695)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4696) #endif /* CONFIG_PROVE_LOCKING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4698) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4699) * Initialize a lock instance's lock-class mapping info:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4700) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4701) void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4702) struct lock_class_key *key, int subclass,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4703) u8 inner, u8 outer, u8 lock_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4704) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4705) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4707) for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4708) lock->class_cache[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4709)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4710) #ifdef CONFIG_LOCK_STAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4711) lock->cpu = raw_smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4712) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4714) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4715) * Can't be having no nameless bastards around this place!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4716) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4717) if (DEBUG_LOCKS_WARN_ON(!name)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4718) lock->name = "NULL";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4719) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4720) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4722) lock->name = name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4723)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4724) lock->wait_type_outer = outer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4725) lock->wait_type_inner = inner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4726) lock->lock_type = lock_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4728) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4729) * No key, no joy, we need to hash something.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4730) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4731) if (DEBUG_LOCKS_WARN_ON(!key))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4732) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4733) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4734) * Sanity check, the lock-class key must either have been allocated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4735) * statically or must have been registered as a dynamic key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4736) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4737) if (!static_obj(key) && !is_dynamic_key(key)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4738) if (debug_locks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4739) printk(KERN_ERR "BUG: key %px has not been registered!\n", key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4740) DEBUG_LOCKS_WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4741) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4742) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4743) lock->key = key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4744)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4745) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4746) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4748) if (subclass) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4749) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4750)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4751) if (DEBUG_LOCKS_WARN_ON(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4752) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4753)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4754) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4755) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4756) register_lock_class(lock, subclass, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4757) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4758) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4759) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4760) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4761) EXPORT_SYMBOL_GPL(lockdep_init_map_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4763) struct lock_class_key __lockdep_no_validate__;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4764) EXPORT_SYMBOL_GPL(__lockdep_no_validate__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4766) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4767) print_lock_nested_lock_not_held(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4768) struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4769) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4770) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4771) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4772) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4773) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4774) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4776) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4777) pr_warn("==================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4778) pr_warn("WARNING: Nested lock was not taken\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4779) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4780) pr_warn("----------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4782) pr_warn("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4783) print_lock(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4784)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4785) pr_warn("\nbut this task is not holding:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4786) pr_warn("%s\n", hlock->nest_lock->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4787)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4788) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4789) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4790)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4791) pr_warn("\nother info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4792) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4794) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4795) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4796) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4797)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4798) static int __lock_is_held(const struct lockdep_map *lock, int read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4799)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4800) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4801) * This gets called for every mutex_lock*()/spin_lock*() operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4802) * We maintain the dependency maps and validate the locking attempt:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4803) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4804) * The callers must make sure that IRQs are disabled before calling it,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4805) * otherwise we could get an interrupt which would want to take locks,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4806) * which would end up in lockdep again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4807) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4808) static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4809) int trylock, int read, int check, int hardirqs_off,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4810) struct lockdep_map *nest_lock, unsigned long ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4811) int references, int pin_count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4812) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4813) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4814) struct lock_class *class = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4815) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4816) unsigned int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4817) int chain_head = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4818) int class_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4819) u64 chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4820)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4821) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4822) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4823)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4824) if (!prove_locking || lock->key == &__lockdep_no_validate__)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4825) check = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4826)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4827) if (subclass < NR_LOCKDEP_CACHING_CLASSES)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4828) class = lock->class_cache[subclass];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4829) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4830) * Not cached?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4831) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4832) if (unlikely(!class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4833) class = register_lock_class(lock, subclass, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4834) if (!class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4835) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4836) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4837)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4838) debug_class_ops_inc(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4839)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4840) if (very_verbose(class)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4841) printk("\nacquire class [%px] %s", class->key, class->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4842) if (class->name_version > 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4843) printk(KERN_CONT "#%d", class->name_version);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4844) printk(KERN_CONT "\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4845) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4846) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4848) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4849) * Add the lock to the list of currently held locks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4850) * (we dont increase the depth just yet, up until the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4851) * dependency checks are done)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4852) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4853) depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4854) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4855) * Ran out of static storage for our per-task lock stack again have we?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4856) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4857) if (DEBUG_LOCKS_WARN_ON(depth >= MAX_LOCK_DEPTH))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4858) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4859)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4860) class_idx = class - lock_classes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4862) if (depth) { /* we're holding locks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4863) hlock = curr->held_locks + depth - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4864) if (hlock->class_idx == class_idx && nest_lock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4865) if (!references)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4866) references++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4867)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4868) if (!hlock->references)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4869) hlock->references++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4870)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4871) hlock->references += references;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4872)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4873) /* Overflow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4874) if (DEBUG_LOCKS_WARN_ON(hlock->references < references))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4875) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4877) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4878) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4879) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4880)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4881) hlock = curr->held_locks + depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4882) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4883) * Plain impossible, we just registered it and checked it weren't no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4884) * NULL like.. I bet this mushroom I ate was good!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4885) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4886) if (DEBUG_LOCKS_WARN_ON(!class))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4887) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4888) hlock->class_idx = class_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4889) hlock->acquire_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4890) hlock->instance = lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4891) hlock->nest_lock = nest_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4892) hlock->irq_context = task_irq_context(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4893) hlock->trylock = trylock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4894) hlock->read = read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4895) hlock->check = check;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4896) hlock->hardirqs_off = !!hardirqs_off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4897) hlock->references = references;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4898) #ifdef CONFIG_LOCK_STAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4899) hlock->waittime_stamp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4900) hlock->holdtime_stamp = lockstat_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4901) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4902) hlock->pin_count = pin_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4904) if (check_wait_context(curr, hlock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4905) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4906)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4907) /* Initialize the lock usage bit */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4908) if (!mark_usage(curr, hlock, check))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4909) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4910)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4911) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4912) * Calculate the chain hash: it's the combined hash of all the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4913) * lock keys along the dependency chain. We save the hash value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4914) * at every step so that we can get the current hash easily
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4915) * after unlock. The chain hash is then used to cache dependency
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4916) * results.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4917) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4918) * The 'key ID' is what is the most compact key value to drive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4919) * the hash, not class->key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4920) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4921) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4922) * Whoops, we did it again.. class_idx is invalid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4923) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4924) if (DEBUG_LOCKS_WARN_ON(!test_bit(class_idx, lock_classes_in_use)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4925) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4926)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4927) chain_key = curr->curr_chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4928) if (!depth) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4929) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4930) * How can we have a chain hash when we ain't got no keys?!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4931) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4932) if (DEBUG_LOCKS_WARN_ON(chain_key != INITIAL_CHAIN_KEY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4933) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4934) chain_head = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4935) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4936)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4937) hlock->prev_chain_key = chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4938) if (separate_irq_context(curr, hlock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4939) chain_key = INITIAL_CHAIN_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4940) chain_head = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4941) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4942) chain_key = iterate_chain_key(chain_key, hlock_id(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4943)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4944) if (nest_lock && !__lock_is_held(nest_lock, -1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4945) print_lock_nested_lock_not_held(curr, hlock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4946) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4947) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4948)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4949) if (!debug_locks_silent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4950) WARN_ON_ONCE(depth && !hlock_class(hlock - 1)->key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4951) WARN_ON_ONCE(!hlock_class(hlock)->key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4952) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4953)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4954) if (!validate_chain(curr, hlock, chain_head, chain_key))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4955) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4956)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4957) curr->curr_chain_key = chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4958) curr->lockdep_depth++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4959) check_chain_key(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4960) #ifdef CONFIG_DEBUG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4961) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4962) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4963) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4964) if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4965) debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4966) print_lockdep_off("BUG: MAX_LOCK_DEPTH too low!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4967) printk(KERN_DEBUG "depth: %i max: %lu!\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4968) curr->lockdep_depth, MAX_LOCK_DEPTH);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4969)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4970) lockdep_print_held_locks(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4971) debug_show_all_locks();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4972) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4973)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4974) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4975) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4976)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4977) if (unlikely(curr->lockdep_depth > max_lockdep_depth))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4978) max_lockdep_depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4979)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4980) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4981) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4982)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4983) static void print_unlock_imbalance_bug(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4984) struct lockdep_map *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4985) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4986) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4987) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4988) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4989) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4990) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4992) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4993) pr_warn("=====================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4994) pr_warn("WARNING: bad unlock balance detected!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4995) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4996) pr_warn("-------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4997) pr_warn("%s/%d is trying to release lock (",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4998) curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4999) print_lockdep_cache(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5000) pr_cont(") at:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5001) print_ip_sym(KERN_WARNING, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5002) pr_warn("but there are no more locks to release!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5003) pr_warn("\nother info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5004) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5005)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5006) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5007) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5008) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5009)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5010) static noinstr int match_held_lock(const struct held_lock *hlock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5011) const struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5012) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5013) if (hlock->instance == lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5014) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5015)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5016) if (hlock->references) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5017) const struct lock_class *class = lock->class_cache[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5019) if (!class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5020) class = look_up_lock_class(lock, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5022) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5023) * If look_up_lock_class() failed to find a class, we're trying
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5024) * to test if we hold a lock that has never yet been acquired.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5025) * Clearly if the lock hasn't been acquired _ever_, we're not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5026) * holding it either, so report failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5027) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5028) if (!class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5029) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5030)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5031) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5032) * References, but not a lock we're actually ref-counting?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5033) * State got messed up, follow the sites that change ->references
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5034) * and try to make sense of it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5035) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5036) if (DEBUG_LOCKS_WARN_ON(!hlock->nest_lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5037) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5039) if (hlock->class_idx == class - lock_classes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5040) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5041) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5042)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5043) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5044) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5045)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5046) /* @depth must not be zero */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5047) static struct held_lock *find_held_lock(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5048) struct lockdep_map *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5049) unsigned int depth, int *idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5050) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5051) struct held_lock *ret, *hlock, *prev_hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5052) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5054) i = depth - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5055) hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5056) ret = hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5057) if (match_held_lock(hlock, lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5058) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5059)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5060) ret = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5061) for (i--, prev_hlock = hlock--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5062) i >= 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5063) i--, prev_hlock = hlock--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5064) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5065) * We must not cross into another context:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5066) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5067) if (prev_hlock->irq_context != hlock->irq_context) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5068) ret = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5069) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5070) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5071) if (match_held_lock(hlock, lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5072) ret = hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5073) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5074) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5075) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5076)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5077) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5078) *idx = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5079) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5080) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5081)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5082) static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5083) int idx, unsigned int *merged)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5084) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5085) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5086) int first_idx = idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5087)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5088) if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5089) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5090)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5091) for (hlock = curr->held_locks + idx; idx < depth; idx++, hlock++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5092) switch (__lock_acquire(hlock->instance,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5093) hlock_class(hlock)->subclass,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5094) hlock->trylock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5095) hlock->read, hlock->check,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5096) hlock->hardirqs_off,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5097) hlock->nest_lock, hlock->acquire_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5098) hlock->references, hlock->pin_count)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5099) case 0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5100) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5101) case 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5102) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5103) case 2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5104) *merged += (idx == first_idx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5105) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5106) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5107) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5108) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5111) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5114) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5115) __lock_set_class(struct lockdep_map *lock, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5116) struct lock_class_key *key, unsigned int subclass,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5117) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5118) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5119) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5120) unsigned int depth, merged = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5121) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5122) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5123) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5125) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5126) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5128) depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5129) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5130) * This function is about (re)setting the class of a held lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5131) * yet we're not actually holding any locks. Naughty user!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5132) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5133) if (DEBUG_LOCKS_WARN_ON(!depth))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5134) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5136) hlock = find_held_lock(curr, lock, depth, &i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5137) if (!hlock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5138) print_unlock_imbalance_bug(curr, lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5139) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5142) lockdep_init_map_waits(lock, name, key, 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5143) lock->wait_type_inner,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5144) lock->wait_type_outer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5145) class = register_lock_class(lock, subclass, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5146) hlock->class_idx = class - lock_classes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5148) curr->lockdep_depth = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5149) curr->curr_chain_key = hlock->prev_chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5151) if (reacquire_held_locks(curr, depth, i, &merged))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5152) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5154) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5155) * I took it apart and put it back together again, except now I have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5156) * these 'spare' parts.. where shall I put them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5157) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5158) if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - merged))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5159) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5160) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5163) static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5164) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5165) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5166) unsigned int depth, merged = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5167) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5168) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5170) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5171) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5173) depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5174) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5175) * This function is about (re)setting the class of a held lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5176) * yet we're not actually holding any locks. Naughty user!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5177) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5178) if (DEBUG_LOCKS_WARN_ON(!depth))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5179) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5181) hlock = find_held_lock(curr, lock, depth, &i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5182) if (!hlock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5183) print_unlock_imbalance_bug(curr, lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5184) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5187) curr->lockdep_depth = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5188) curr->curr_chain_key = hlock->prev_chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5190) WARN(hlock->read, "downgrading a read lock");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5191) hlock->read = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5192) hlock->acquire_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5194) if (reacquire_held_locks(curr, depth, i, &merged))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5195) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5197) /* Merging can't happen with unchanged classes.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5198) if (DEBUG_LOCKS_WARN_ON(merged))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5199) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5201) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5202) * I took it apart and put it back together again, except now I have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5203) * these 'spare' parts.. where shall I put them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5204) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5205) if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5206) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5208) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5211) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5212) * Remove the lock from the list of currently held locks - this gets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5213) * called on mutex_unlock()/spin_unlock*() (or on a failed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5214) * mutex_lock_interruptible()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5215) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5216) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5217) __lock_release(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5218) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5219) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5220) unsigned int depth, merged = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5221) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5222) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5224) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5225) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5227) depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5228) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5229) * So we're all set to release this lock.. wait what lock? We don't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5230) * own any locks, you've been drinking again?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5231) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5232) if (depth <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5233) print_unlock_imbalance_bug(curr, lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5234) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5237) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5238) * Check whether the lock exists in the current stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5239) * of held locks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5240) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5241) hlock = find_held_lock(curr, lock, depth, &i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5242) if (!hlock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5243) print_unlock_imbalance_bug(curr, lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5244) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5247) if (hlock->instance == lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5248) lock_release_holdtime(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5250) WARN(hlock->pin_count, "releasing a pinned lock\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5252) if (hlock->references) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5253) hlock->references--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5254) if (hlock->references) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5255) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5256) * We had, and after removing one, still have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5257) * references, the current lock stack is still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5258) * valid. We're done!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5259) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5260) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5264) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5265) * We have the right lock to unlock, 'hlock' points to it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5266) * Now we remove it from the stack, and add back the other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5267) * entries (if any), recalculating the hash along the way:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5268) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5269)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5270) curr->lockdep_depth = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5271) curr->curr_chain_key = hlock->prev_chain_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5273) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5274) * The most likely case is when the unlock is on the innermost
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5275) * lock. In this case, we are done!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5276) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5277) if (i == depth-1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5278) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5280) if (reacquire_held_locks(curr, depth, i + 1, &merged))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5281) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5283) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5284) * We had N bottles of beer on the wall, we drank one, but now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5285) * there's not N-1 bottles of beer left on the wall...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5286) * Pouring two of the bottles together is acceptable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5287) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5288) DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - merged);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5290) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5291) * Since reacquire_held_locks() would have called check_chain_key()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5292) * indirectly via __lock_acquire(), we don't need to do it again
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5293) * on return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5294) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5295) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5296) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5298) static __always_inline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5299) int __lock_is_held(const struct lockdep_map *lock, int read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5300) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5301) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5302) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5304) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5305) struct held_lock *hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5307) if (match_held_lock(hlock, lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5308) if (read == -1 || !!hlock->read == read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5309) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5311) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5313) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5315) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5316) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5318) static struct pin_cookie __lock_pin_lock(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5319) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5320) struct pin_cookie cookie = NIL_COOKIE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5321) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5322) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5324) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5325) return cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5327) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5328) struct held_lock *hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5330) if (match_held_lock(hlock, lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5331) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5332) * Grab 16bits of randomness; this is sufficient to not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5333) * be guessable and still allows some pin nesting in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5334) * our u32 pin_count.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5335) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5336) cookie.val = 1 + (prandom_u32() >> 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5337) hlock->pin_count += cookie.val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5338) return cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5339) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5342) WARN(1, "pinning an unheld lock\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5343) return cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5344) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5346) static void __lock_repin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5347) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5348) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5349) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5351) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5352) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5354) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5355) struct held_lock *hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5357) if (match_held_lock(hlock, lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5358) hlock->pin_count += cookie.val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5359) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5360) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5361) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5363) WARN(1, "pinning an unheld lock\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5366) static void __lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5367) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5368) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5369) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5371) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5372) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5374) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5375) struct held_lock *hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5377) if (match_held_lock(hlock, lock)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5378) if (WARN(!hlock->pin_count, "unpinning an unpinned lock\n"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5379) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5381) hlock->pin_count -= cookie.val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5383) if (WARN((int)hlock->pin_count < 0, "pin count corrupted\n"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5384) hlock->pin_count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5386) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5387) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5388) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5390) WARN(1, "unpinning an unheld lock\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5393) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5394) * Check whether we follow the irq-flags state precisely:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5395) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5396) static noinstr void check_flags(unsigned long flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5397) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5398) #if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5399) if (!debug_locks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5400) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5402) /* Get the warning out.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5403) instrumentation_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5405) if (irqs_disabled_flags(flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5406) if (DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5407) printk("possible reason: unannotated irqs-off.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5408) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5409) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5410) if (DEBUG_LOCKS_WARN_ON(!lockdep_hardirqs_enabled())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5411) printk("possible reason: unannotated irqs-on.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5412) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5413) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5416) * We dont accurately track softirq state in e.g.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5417) * hardirq contexts (such as on 4KSTACKS), so only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5418) * check if not in hardirq contexts:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5419) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5420) if (!hardirq_count()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5421) if (softirq_count()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5422) /* like the above, but with softirqs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5423) DEBUG_LOCKS_WARN_ON(current->softirqs_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5424) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5425) /* lick the above, does it taste good? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5426) DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5427) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5430) if (!debug_locks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5431) print_irqtrace_events(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5433) instrumentation_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5434) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5435) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5437) void lock_set_class(struct lockdep_map *lock, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5438) struct lock_class_key *key, unsigned int subclass,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5439) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5440) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5441) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5443) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5444) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5446) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5447) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5448) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5449) if (__lock_set_class(lock, name, key, subclass, ip))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5450) check_chain_key(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5451) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5452) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5453) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5454) EXPORT_SYMBOL_GPL(lock_set_class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5456) void lock_downgrade(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5457) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5458) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5460) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5461) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5463) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5464) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5465) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5466) if (__lock_downgrade(lock, ip))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5467) check_chain_key(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5468) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5469) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5471) EXPORT_SYMBOL_GPL(lock_downgrade);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5473) /* NMI context !!! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5474) static void verify_lock_unused(struct lockdep_map *lock, struct held_lock *hlock, int subclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5475) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5476) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5477) struct lock_class *class = look_up_lock_class(lock, subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5478) unsigned long mask = LOCKF_USED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5480) /* if it doesn't have a class (yet), it certainly hasn't been used yet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5481) if (!class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5482) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5484) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5485) * READ locks only conflict with USED, such that if we only ever use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5486) * READ locks, there is no deadlock possible -- RCU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5487) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5488) if (!hlock->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5489) mask |= LOCKF_USED_READ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5491) if (!(class->usage_mask & mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5492) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5494) hlock->class_idx = class - lock_classes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5496) print_usage_bug(current, hlock, LOCK_USED, LOCK_USAGE_STATES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5497) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5498) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5500) static bool lockdep_nmi(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5501) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5502) if (raw_cpu_read(lockdep_recursion))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5503) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5505) if (!in_nmi())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5506) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5508) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5509) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5511) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5512) * read_lock() is recursive if:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5513) * 1. We force lockdep think this way in selftests or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5514) * 2. The implementation is not queued read/write lock or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5515) * 3. The locker is at an in_interrupt() context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5516) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5517) bool read_lock_is_recursive(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5518) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5519) return force_read_lock_recursive ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5520) !IS_ENABLED(CONFIG_QUEUED_RWLOCKS) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5521) in_interrupt();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5522) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5523) EXPORT_SYMBOL_GPL(read_lock_is_recursive);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5525) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5526) * We are not always called with irqs disabled - do that here,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5527) * and also avoid lockdep recursion:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5528) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5529) void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5530) int trylock, int read, int check,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5531) struct lockdep_map *nest_lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5532) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5533) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5535) trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5537) if (!debug_locks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5538) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5540) if (unlikely(!lockdep_enabled())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5541) /* XXX allow trylock from NMI ?!? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5542) if (lockdep_nmi() && !trylock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5543) struct held_lock hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5544)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5545) hlock.acquire_ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5546) hlock.instance = lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5547) hlock.nest_lock = nest_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5548) hlock.irq_context = 2; // XXX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5549) hlock.trylock = trylock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5550) hlock.read = read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5551) hlock.check = check;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5552) hlock.hardirqs_off = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5553) hlock.references = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5555) verify_lock_unused(lock, &hlock, subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5556) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5557) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5558) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5559)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5560) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5561) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5563) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5564) __lock_acquire(lock, subclass, trylock, read, check,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5565) irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5566) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5567) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5568) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5569) EXPORT_SYMBOL_GPL(lock_acquire);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5570)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5571) void lock_release(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5572) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5573) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5575) trace_lock_release(lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5577) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5578) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5580) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5581) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5583) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5584) if (__lock_release(lock, ip))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5585) check_chain_key(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5586) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5587) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5588) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5589) EXPORT_SYMBOL_GPL(lock_release);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5591) noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5592) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5593) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5594) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5596) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5597) return 1; /* avoid false negative lockdep_assert_held() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5599) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5600) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5602) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5603) ret = __lock_is_held(lock, read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5604) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5605) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5607) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5608) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5609) EXPORT_SYMBOL_GPL(lock_is_held_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5610) NOKPROBE_SYMBOL(lock_is_held_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5612) struct pin_cookie lock_pin_lock(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5613) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5614) struct pin_cookie cookie = NIL_COOKIE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5615) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5617) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5618) return cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5620) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5621) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5623) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5624) cookie = __lock_pin_lock(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5625) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5626) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5628) return cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5629) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5630) EXPORT_SYMBOL_GPL(lock_pin_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5631)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5632) void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5633) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5634) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5636) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5637) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5638)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5639) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5640) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5642) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5643) __lock_repin_lock(lock, cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5644) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5645) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5646) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5647) EXPORT_SYMBOL_GPL(lock_repin_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5649) void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5650) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5651) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5653) if (unlikely(!lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5654) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5656) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5657) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5658)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5659) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5660) __lock_unpin_lock(lock, cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5661) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5662) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5663) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5664) EXPORT_SYMBOL_GPL(lock_unpin_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5666) #ifdef CONFIG_LOCK_STAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5667) static void print_lock_contention_bug(struct task_struct *curr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5668) struct lockdep_map *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5669) unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5670) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5671) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5672) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5673) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5674) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5676) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5677) pr_warn("=================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5678) pr_warn("WARNING: bad contention detected!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5679) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5680) pr_warn("---------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5681) pr_warn("%s/%d is trying to contend lock (",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5682) curr->comm, task_pid_nr(curr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5683) print_lockdep_cache(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5684) pr_cont(") at:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5685) print_ip_sym(KERN_WARNING, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5686) pr_warn("but there are no locks held!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5687) pr_warn("\nother info that might help us debug this:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5688) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5689)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5690) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5691) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5692) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5694) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5695) __lock_contended(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5696) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5697) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5698) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5699) struct lock_class_stats *stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5700) unsigned int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5701) int i, contention_point, contending_point;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5703) depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5704) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5705) * Whee, we contended on this lock, except it seems we're not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5706) * actually trying to acquire anything much at all..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5707) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5708) if (DEBUG_LOCKS_WARN_ON(!depth))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5709) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5710)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5711) hlock = find_held_lock(curr, lock, depth, &i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5712) if (!hlock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5713) print_lock_contention_bug(curr, lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5714) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5715) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5717) if (hlock->instance != lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5718) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5720) hlock->waittime_stamp = lockstat_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5722) contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5723) contending_point = lock_point(hlock_class(hlock)->contending_point,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5724) lock->ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5725)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5726) stats = get_lock_stats(hlock_class(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5727) if (contention_point < LOCKSTAT_POINTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5728) stats->contention_point[contention_point]++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5729) if (contending_point < LOCKSTAT_POINTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5730) stats->contending_point[contending_point]++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5731) if (lock->cpu != smp_processor_id())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5732) stats->bounces[bounce_contended + !!hlock->read]++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5733) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5734)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5735) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5736) __lock_acquired(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5737) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5738) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5739) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5740) struct lock_class_stats *stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5741) unsigned int depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5742) u64 now, waittime = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5743) int i, cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5744)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5745) depth = curr->lockdep_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5746) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5747) * Yay, we acquired ownership of this lock we didn't try to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5748) * acquire, how the heck did that happen?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5749) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5750) if (DEBUG_LOCKS_WARN_ON(!depth))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5751) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5753) hlock = find_held_lock(curr, lock, depth, &i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5754) if (!hlock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5755) print_lock_contention_bug(curr, lock, _RET_IP_);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5756) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5757) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5758)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5759) if (hlock->instance != lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5760) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5762) cpu = smp_processor_id();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5763) if (hlock->waittime_stamp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5764) now = lockstat_clock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5765) waittime = now - hlock->waittime_stamp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5766) hlock->holdtime_stamp = now;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5767) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5769) stats = get_lock_stats(hlock_class(hlock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5770) if (waittime) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5771) if (hlock->read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5772) lock_time_inc(&stats->read_waittime, waittime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5773) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5774) lock_time_inc(&stats->write_waittime, waittime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5775) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5776) if (lock->cpu != cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5777) stats->bounces[bounce_acquired + !!hlock->read]++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5778)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5779) lock->cpu = cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5780) lock->ip = ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5781) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5782)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5783) void lock_contended(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5784) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5785) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5786)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5787) trace_lock_contended(lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5788)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5789) if (unlikely(!lock_stat || !lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5790) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5792) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5793) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5794) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5795) __lock_contended(lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5796) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5797) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5798) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5799) EXPORT_SYMBOL_GPL(lock_contended);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5801) void lock_acquired(struct lockdep_map *lock, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5802) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5803) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5805) trace_lock_acquired(lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5806)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5807) if (unlikely(!lock_stat || !lockdep_enabled()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5808) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5810) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5811) check_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5812) lockdep_recursion_inc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5813) __lock_acquired(lock, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5814) lockdep_recursion_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5815) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5816) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5817) EXPORT_SYMBOL_GPL(lock_acquired);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5818) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5819)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5820) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5821) * Used by the testsuite, sanitize the validator state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5822) * after a simulated failure:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5823) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5824)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5825) void lockdep_reset(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5826) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5827) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5828) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5829)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5830) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5831) lockdep_init_task(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5832) memset(current->held_locks, 0, MAX_LOCK_DEPTH*sizeof(struct held_lock));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5833) nr_hardirq_chains = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5834) nr_softirq_chains = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5835) nr_process_chains = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5836) debug_locks = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5837) for (i = 0; i < CHAINHASH_SIZE; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5838) INIT_HLIST_HEAD(chainhash_table + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5839) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5840) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5841)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5842) /* Remove a class from a lock chain. Must be called with the graph lock held. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5843) static void remove_class_from_lock_chain(struct pending_free *pf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5844) struct lock_chain *chain,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5845) struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5846) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5847) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5848) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5850) for (i = chain->base; i < chain->base + chain->depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5851) if (chain_hlock_class_idx(chain_hlocks[i]) != class - lock_classes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5852) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5853) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5854) * Each lock class occurs at most once in a lock chain so once
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5855) * we found a match we can break out of this loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5856) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5857) goto free_lock_chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5858) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5859) /* Since the chain has not been modified, return. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5860) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5862) free_lock_chain:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5863) free_chain_hlocks(chain->base, chain->depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5864) /* Overwrite the chain key for concurrent RCU readers. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5865) WRITE_ONCE(chain->chain_key, INITIAL_CHAIN_KEY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5866) dec_chains(chain->irq_context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5867)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5868) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5869) * Note: calling hlist_del_rcu() from inside a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5870) * hlist_for_each_entry_rcu() loop is safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5871) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5872) hlist_del_rcu(&chain->entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5873) __set_bit(chain - lock_chains, pf->lock_chains_being_freed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5874) nr_zapped_lock_chains++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5875) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5876) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5877)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5878) /* Must be called with the graph lock held. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5879) static void remove_class_from_lock_chains(struct pending_free *pf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5880) struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5881) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5882) struct lock_chain *chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5883) struct hlist_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5884) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5885)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5886) for (i = 0; i < ARRAY_SIZE(chainhash_table); i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5887) head = chainhash_table + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5888) hlist_for_each_entry_rcu(chain, head, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5889) remove_class_from_lock_chain(pf, chain, class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5890) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5891) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5892) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5893)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5894) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5895) * Remove all references to a lock class. The caller must hold the graph lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5896) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5897) static void zap_class(struct pending_free *pf, struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5898) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5899) struct lock_list *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5900) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5901)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5902) WARN_ON_ONCE(!class->key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5904) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5905) * Remove all dependencies this lock is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5906) * involved in:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5907) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5908) for_each_set_bit(i, list_entries_in_use, ARRAY_SIZE(list_entries)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5909) entry = list_entries + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5910) if (entry->class != class && entry->links_to != class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5911) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5912) __clear_bit(i, list_entries_in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5913) nr_list_entries--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5914) list_del_rcu(&entry->entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5915) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5916) if (list_empty(&class->locks_after) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5917) list_empty(&class->locks_before)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5918) list_move_tail(&class->lock_entry, &pf->zapped);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5919) hlist_del_rcu(&class->hash_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5920) WRITE_ONCE(class->key, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5921) WRITE_ONCE(class->name, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5922) nr_lock_classes--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5923) __clear_bit(class - lock_classes, lock_classes_in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5924) if (class - lock_classes == max_lock_class_idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5925) max_lock_class_idx--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5926) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5927) WARN_ONCE(true, "%s() failed for class %s\n", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5928) class->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5929) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5930)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5931) remove_class_from_lock_chains(pf, class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5932) nr_zapped_classes++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5933) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5934)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5935) static void reinit_class(struct lock_class *class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5936) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5937) void *const p = class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5938) const unsigned int offset = offsetof(struct lock_class, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5939)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5940) WARN_ON_ONCE(!class->lock_entry.next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5941) WARN_ON_ONCE(!list_empty(&class->locks_after));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5942) WARN_ON_ONCE(!list_empty(&class->locks_before));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5943) memset(p + offset, 0, sizeof(*class) - offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5944) WARN_ON_ONCE(!class->lock_entry.next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5945) WARN_ON_ONCE(!list_empty(&class->locks_after));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5946) WARN_ON_ONCE(!list_empty(&class->locks_before));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5947) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5948)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5949) static inline int within(const void *addr, void *start, unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5950) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5951) return addr >= start && addr < start + size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5952) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5953)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5954) static bool inside_selftest(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5955) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5956) return current == lockdep_selftest_task_struct;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5957) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5958)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5959) /* The caller must hold the graph lock. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5960) static struct pending_free *get_pending_free(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5961) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5962) return delayed_free.pf + delayed_free.index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5963) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5965) static void free_zapped_rcu(struct rcu_head *cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5966)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5967) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5968) * Schedule an RCU callback if no RCU callback is pending. Must be called with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5969) * the graph lock held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5970) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5971) static void call_rcu_zapped(struct pending_free *pf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5972) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5973) WARN_ON_ONCE(inside_selftest());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5974)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5975) if (list_empty(&pf->zapped))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5976) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5977)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5978) if (delayed_free.scheduled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5979) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5980)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5981) delayed_free.scheduled = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5982)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5983) WARN_ON_ONCE(delayed_free.pf + delayed_free.index != pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5984) delayed_free.index ^= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5985)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5986) call_rcu(&delayed_free.rcu_head, free_zapped_rcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5987) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5989) /* The caller must hold the graph lock. May be called from RCU context. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5990) static void __free_zapped_classes(struct pending_free *pf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5991) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5992) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5993)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5994) check_data_structures();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5995)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5996) list_for_each_entry(class, &pf->zapped, lock_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5997) reinit_class(class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5998)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5999) list_splice_init(&pf->zapped, &free_lock_classes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6001) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6002) bitmap_andnot(lock_chains_in_use, lock_chains_in_use,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6003) pf->lock_chains_being_freed, ARRAY_SIZE(lock_chains));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6004) bitmap_clear(pf->lock_chains_being_freed, 0, ARRAY_SIZE(lock_chains));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6005) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6006) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6007)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6008) static void free_zapped_rcu(struct rcu_head *ch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6009) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6010) struct pending_free *pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6011) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6012)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6013) if (WARN_ON_ONCE(ch != &delayed_free.rcu_head))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6014) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6015)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6016) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6017) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6019) /* closed head */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6020) pf = delayed_free.pf + (delayed_free.index ^ 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6021) __free_zapped_classes(pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6022) delayed_free.scheduled = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6023)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6024) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6025) * If there's anything on the open list, close and start a new callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6026) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6027) call_rcu_zapped(delayed_free.pf + delayed_free.index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6028)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6029) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6030) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6031) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6032)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6033) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6034) * Remove all lock classes from the class hash table and from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6035) * all_lock_classes list whose key or name is in the address range [start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6036) * start + size). Move these lock classes to the zapped_classes list. Must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6037) * be called with the graph lock held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6038) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6039) static void __lockdep_free_key_range(struct pending_free *pf, void *start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6040) unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6041) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6042) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6043) struct hlist_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6044) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6045)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6046) /* Unhash all classes that were created by a module. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6047) for (i = 0; i < CLASSHASH_SIZE; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6048) head = classhash_table + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6049) hlist_for_each_entry_rcu(class, head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6050) if (!within(class->key, start, size) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6051) !within(class->name, start, size))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6052) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6053) zap_class(pf, class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6054) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6055) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6056) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6057)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6058) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6059) * Used in module.c to remove lock classes from memory that is going to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6060) * freed; and possibly re-used by other modules.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6061) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6062) * We will have had one synchronize_rcu() before getting here, so we're
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6063) * guaranteed nobody will look up these exact classes -- they're properly dead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6064) * but still allocated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6065) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6066) static void lockdep_free_key_range_reg(void *start, unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6067) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6068) struct pending_free *pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6069) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6070)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6071) init_data_structures_once();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6073) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6074) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6075) pf = get_pending_free();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6076) __lockdep_free_key_range(pf, start, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6077) call_rcu_zapped(pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6078) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6079) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6080)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6081) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6082) * Wait for any possible iterators from look_up_lock_class() to pass
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6083) * before continuing to free the memory they refer to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6084) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6085) synchronize_rcu();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6086) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6087)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6088) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6089) * Free all lockdep keys in the range [start, start+size). Does not sleep.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6090) * Ignores debug_locks. Must only be used by the lockdep selftests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6091) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6092) static void lockdep_free_key_range_imm(void *start, unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6093) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6094) struct pending_free *pf = delayed_free.pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6095) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6096)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6097) init_data_structures_once();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6098)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6099) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6100) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6101) __lockdep_free_key_range(pf, start, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6102) __free_zapped_classes(pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6103) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6104) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6107) void lockdep_free_key_range(void *start, unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6109) init_data_structures_once();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6111) if (inside_selftest())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6112) lockdep_free_key_range_imm(start, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6113) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6114) lockdep_free_key_range_reg(start, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6117) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6118) * Check whether any element of the @lock->class_cache[] array refers to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6119) * registered lock class. The caller must hold either the graph lock or the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6120) * RCU read lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6121) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6122) static bool lock_class_cache_is_registered(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6124) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6125) struct hlist_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6126) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6128) for (i = 0; i < CLASSHASH_SIZE; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6129) head = classhash_table + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6130) hlist_for_each_entry_rcu(class, head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6131) for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6132) if (lock->class_cache[j] == class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6133) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6136) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6139) /* The caller must hold the graph lock. Does not sleep. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6140) static void __lockdep_reset_lock(struct pending_free *pf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6141) struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6142) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6143) struct lock_class *class;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6144) int j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6146) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6147) * Remove all classes this lock might have:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6149) for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6150) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6151) * If the class exists we look it up and zap it:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6152) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6153) class = look_up_lock_class(lock, j);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6154) if (class)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6155) zap_class(pf, class);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6156) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6157) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6158) * Debug check: in the end all mapped classes should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6159) * be gone.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6161) if (WARN_ON_ONCE(lock_class_cache_is_registered(lock)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6162) debug_locks_off();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6165) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6166) * Remove all information lockdep has about a lock if debug_locks == 1. Free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6167) * released data structures from RCU context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6168) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6169) static void lockdep_reset_lock_reg(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6170) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6171) struct pending_free *pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6172) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6173) int locked;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6175) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6176) locked = graph_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6177) if (!locked)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6178) goto out_irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6180) pf = get_pending_free();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6181) __lockdep_reset_lock(pf, lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6182) call_rcu_zapped(pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6184) graph_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6185) out_irq:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6186) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6189) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6190) * Reset a lock. Does not sleep. Ignores debug_locks. Must only be used by the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6191) * lockdep selftests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6192) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6193) static void lockdep_reset_lock_imm(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6194) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6195) struct pending_free *pf = delayed_free.pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6196) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6198) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6199) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6200) __lockdep_reset_lock(pf, lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6201) __free_zapped_classes(pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6202) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6203) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6206) void lockdep_reset_lock(struct lockdep_map *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6207) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6208) init_data_structures_once();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6210) if (inside_selftest())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6211) lockdep_reset_lock_imm(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6212) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6213) lockdep_reset_lock_reg(lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6216) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6217) * Unregister a dynamically allocated key.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6218) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6219) * Unlike lockdep_register_key(), a search is always done to find a matching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6220) * key irrespective of debug_locks to avoid potential invalid access to freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6221) * memory in lock_class entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6222) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6223) void lockdep_unregister_key(struct lock_class_key *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6224) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6225) struct hlist_head *hash_head = keyhashentry(key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6226) struct lock_class_key *k;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6227) struct pending_free *pf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6228) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6229) bool found = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6231) might_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6233) if (WARN_ON_ONCE(static_obj(key)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6234) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6236) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6237) lockdep_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6239) hlist_for_each_entry_rcu(k, hash_head, hash_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6240) if (k == key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6241) hlist_del_rcu(&k->hash_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6242) found = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6243) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6244) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6246) WARN_ON_ONCE(!found && debug_locks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6247) if (found) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6248) pf = get_pending_free();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6249) __lockdep_free_key_range(pf, key, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6250) call_rcu_zapped(pf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6252) lockdep_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6253) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6255) /* Wait until is_dynamic_key() has finished accessing k->hash_entry. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6256) synchronize_rcu();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6258) EXPORT_SYMBOL_GPL(lockdep_unregister_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6260) void __init lockdep_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6261) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6262) printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6264) printk("... MAX_LOCKDEP_SUBCLASSES: %lu\n", MAX_LOCKDEP_SUBCLASSES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6265) printk("... MAX_LOCK_DEPTH: %lu\n", MAX_LOCK_DEPTH);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6266) printk("... MAX_LOCKDEP_KEYS: %lu\n", MAX_LOCKDEP_KEYS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6267) printk("... CLASSHASH_SIZE: %lu\n", CLASSHASH_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6268) printk("... MAX_LOCKDEP_ENTRIES: %lu\n", MAX_LOCKDEP_ENTRIES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6269) printk("... MAX_LOCKDEP_CHAINS: %lu\n", MAX_LOCKDEP_CHAINS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6270) printk("... CHAINHASH_SIZE: %lu\n", CHAINHASH_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6272) printk(" memory used by lock dependency info: %zu kB\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6273) (sizeof(lock_classes) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6274) sizeof(lock_classes_in_use) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6275) sizeof(classhash_table) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6276) sizeof(list_entries) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6277) sizeof(list_entries_in_use) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6278) sizeof(chainhash_table) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6279) sizeof(delayed_free)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6280) #ifdef CONFIG_PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6281) + sizeof(lock_cq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6282) + sizeof(lock_chains)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6283) + sizeof(lock_chains_in_use)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6284) + sizeof(chain_hlocks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6285) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6286) ) / 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6287) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6289) #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6290) printk(" memory used for stack traces: %zu kB\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6291) (sizeof(stack_trace) + sizeof(stack_trace_hash)) / 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6292) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6293) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6295) printk(" per task-struct memory footprint: %zu bytes\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6296) sizeof(((struct task_struct *)NULL)->held_locks));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6297) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6299) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6300) print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6301) const void *mem_to, struct held_lock *hlock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6302) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6303) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6304) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6305) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6306) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6308) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6309) pr_warn("=========================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6310) pr_warn("WARNING: held lock freed!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6311) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6312) pr_warn("-------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6313) pr_warn("%s/%d is freeing memory %px-%px, with a lock still held there!\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6314) curr->comm, task_pid_nr(curr), mem_from, mem_to-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6315) print_lock(hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6316) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6318) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6319) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6320) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6321)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6322) static inline int not_in_range(const void* mem_from, unsigned long mem_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6323) const void* lock_from, unsigned long lock_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6324) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6325) return lock_from + lock_len <= mem_from ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6326) mem_from + mem_len <= lock_from;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6327) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6329) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6330) * Called when kernel memory is freed (or unmapped), or if a lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6331) * is destroyed or reinitialized - this code checks whether there is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6332) * any held lock in the memory range of <from> to <to>:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6333) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6334) void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6335) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6336) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6337) struct held_lock *hlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6338) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6339) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6341) if (unlikely(!debug_locks))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6342) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6344) raw_local_irq_save(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6345) for (i = 0; i < curr->lockdep_depth; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6346) hlock = curr->held_locks + i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6348) if (not_in_range(mem_from, mem_len, hlock->instance,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6349) sizeof(*hlock->instance)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6350) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6352) print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6353) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6354) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6355) raw_local_irq_restore(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6357) EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6359) static void print_held_locks_bug(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6360) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6361) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6362) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6363) if (debug_locks_silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6364) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6366) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6367) pr_warn("====================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6368) pr_warn("WARNING: %s/%d still has locks held!\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6369) current->comm, task_pid_nr(current));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6370) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6371) pr_warn("------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6372) lockdep_print_held_locks(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6373) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6374) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6375) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6377) void debug_check_no_locks_held(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6378) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6379) if (unlikely(current->lockdep_depth > 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6380) print_held_locks_bug();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6381) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6382) EXPORT_SYMBOL_GPL(debug_check_no_locks_held);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6384) #ifdef __KERNEL__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6385) void debug_show_all_locks(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6386) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6387) struct task_struct *g, *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6389) if (unlikely(!debug_locks)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6390) pr_warn("INFO: lockdep is turned off.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6391) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6393) pr_warn("\nShowing all locks held in the system:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6395) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6396) for_each_process_thread(g, p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6397) if (!p->lockdep_depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6398) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6399) lockdep_print_held_locks(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6400) touch_nmi_watchdog();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6401) touch_all_softlockup_watchdogs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6402) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6403) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6405) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6406) pr_warn("=============================================\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6407) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6408) EXPORT_SYMBOL_GPL(debug_show_all_locks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6409) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6411) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6412) * Careful: only use this function if you are sure that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6413) * the task cannot run in parallel!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6414) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6415) void debug_show_held_locks(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6416) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6417) if (unlikely(!debug_locks)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6418) printk("INFO: lockdep is turned off.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6419) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6420) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6421) lockdep_print_held_locks(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6422) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6423) EXPORT_SYMBOL_GPL(debug_show_held_locks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6425) asmlinkage __visible void lockdep_sys_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6426) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6427) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6429) if (unlikely(curr->lockdep_depth)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6430) if (!debug_locks_off())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6431) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6432) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6433) pr_warn("================================================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6434) pr_warn("WARNING: lock held when returning to user space!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6435) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6436) pr_warn("------------------------------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6437) pr_warn("%s/%d is leaving the kernel with locks still held!\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6438) curr->comm, curr->pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6439) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6440) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6441)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6442) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6443) * The lock history for each syscall should be independent. So wipe the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6444) * slate clean on return to userspace.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6445) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6446) lockdep_invariant_state(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6449) void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6450) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6451) struct task_struct *curr = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6453) /* Note: the following can be executed concurrently, so be careful. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6454) pr_warn("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6455) pr_warn("=============================\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6456) pr_warn("WARNING: suspicious RCU usage\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6457) print_kernel_ident();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6458) pr_warn("-----------------------------\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6459) pr_warn("%s:%d %s!\n", file, line, s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6460) pr_warn("\nother info that might help us debug this:\n\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6461) pr_warn("\n%srcu_scheduler_active = %d, debug_locks = %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6462) !rcu_lockdep_current_cpu_online()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6463) ? "RCU used illegally from offline CPU!\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6464) : "",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6465) rcu_scheduler_active, debug_locks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6467) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6468) * If a CPU is in the RCU-free window in idle (ie: in the section
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6469) * between rcu_idle_enter() and rcu_idle_exit(), then RCU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6470) * considers that CPU to be in an "extended quiescent state",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6471) * which means that RCU will be completely ignoring that CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6472) * Therefore, rcu_read_lock() and friends have absolutely no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6473) * effect on a CPU running in that state. In other words, even if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6474) * such an RCU-idle CPU has called rcu_read_lock(), RCU might well
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6475) * delete data structures out from under it. RCU really has no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6476) * choice here: we need to keep an RCU-free window in idle where
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6477) * the CPU may possibly enter into low power mode. This way we can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6478) * notice an extended quiescent state to other CPUs that started a grace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6479) * period. Otherwise we would delay any grace period as long as we run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6480) * in the idle task.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6481) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6482) * So complain bitterly if someone does call rcu_read_lock(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6483) * rcu_read_lock_bh() and so on from extended quiescent states.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6484) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6485) if (!rcu_is_watching())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6486) pr_warn("RCU used illegally from extended quiescent state!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6488) lockdep_print_held_locks(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6489) pr_warn("\nstack backtrace:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6490) dump_stack();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6491) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6492) EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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