^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Dynamic function tracing support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Thanks goes to Ingo Molnar, for suggesting the idea.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Mathieu Desnoyers, for suggesting postponing the modifications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Arjan van de Ven, for keeping me straight, and explaining to me
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * the dangers of modifying code on the run.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/hardirq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/memory.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/vmalloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <trace/syscall.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <asm/set_memory.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <asm/kprobes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <asm/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <asm/nops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <asm/text-patching.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #ifdef CONFIG_DYNAMIC_FTRACE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static int ftrace_poke_late = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) int ftrace_arch_code_modify_prepare(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) __acquires(&text_mutex)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * Need to grab text_mutex to prevent a race from module loading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * and live kernel patching from changing the text permissions while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * ftrace has it set to "read/write".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) mutex_lock(&text_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) ftrace_poke_late = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) int ftrace_arch_code_modify_post_process(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) __releases(&text_mutex)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * ftrace_make_{call,nop}() may be called during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * module load, and we need to finish the text_poke_queue()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * that they do, here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) text_poke_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) ftrace_poke_late = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) mutex_unlock(&text_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) static const char *ftrace_nop_replace(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) return ideal_nops[NOP_ATOMIC5];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) static const char *ftrace_call_replace(unsigned long ip, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) return text_gen_insn(CALL_INSN_OPCODE, (void *)ip, (void *)addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) static int ftrace_verify_code(unsigned long ip, const char *old_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) char cur_code[MCOUNT_INSN_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * Note:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * We are paranoid about modifying text, as if a bug was to happen, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * could cause us to read or write to someplace that could cause harm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * Carefully read and modify the code with probe_kernel_*(), and make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * sure what we read is what we expected it to be before modifying it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) /* read the text we want to modify */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) if (copy_from_kernel_nofault(cur_code, (void *)ip, MCOUNT_INSN_SIZE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) /* Make sure it is what we expect it to be */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if (memcmp(cur_code, old_code, MCOUNT_INSN_SIZE) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * Marked __ref because it calls text_poke_early() which is .init.text. That is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * ok because that call will happen early, during boot, when .init sections are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * still present.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static int __ref
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) ftrace_modify_code_direct(unsigned long ip, const char *old_code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) const char *new_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) int ret = ftrace_verify_code(ip, old_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) /* replace the text with the new text */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) if (ftrace_poke_late)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) text_poke_queue((void *)ip, new_code, MCOUNT_INSN_SIZE, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) text_poke_early((void *)ip, new_code, MCOUNT_INSN_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) unsigned long ip = rec->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) const char *new, *old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) old = ftrace_call_replace(ip, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) new = ftrace_nop_replace();
^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) * On boot up, and when modules are loaded, the MCOUNT_ADDR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * is converted to a nop, and will never become MCOUNT_ADDR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * again. This code is either running before SMP (on boot up)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * or before the code will ever be executed (module load).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * We do not want to use the breakpoint version in this case,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * just modify the code directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) if (addr == MCOUNT_ADDR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return ftrace_modify_code_direct(ip, old, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * x86 overrides ftrace_replace_code -- this function will never be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * in this case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) WARN_ONCE(1, "invalid use of ftrace_make_nop");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) unsigned long ip = rec->ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) const char *new, *old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) old = ftrace_nop_replace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) new = ftrace_call_replace(ip, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) /* Should only be called when module is loaded */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) return ftrace_modify_code_direct(rec->ip, old, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * Should never be called:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * As it is only called by __ftrace_replace_code() which is called by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * ftrace_replace_code() that x86 overrides, and by ftrace_update_code()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * which is called to turn mcount into nops or nops into function calls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * but not to convert a function from not using regs to one that uses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * regs, which ftrace_modify_call() is for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) int ftrace_update_ftrace_func(ftrace_func_t func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) unsigned long ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) const char *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) ip = (unsigned long)(&ftrace_call);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) new = ftrace_call_replace(ip, (unsigned long)func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) ip = (unsigned long)(&ftrace_regs_call);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) new = ftrace_call_replace(ip, (unsigned long)func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) void ftrace_replace_code(int enable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) struct ftrace_rec_iter *iter;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) struct dyn_ftrace *rec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) const char *new, *old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) for_ftrace_rec_iter(iter) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) rec = ftrace_rec_iter_record(iter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) switch (ftrace_test_record(rec, enable)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) case FTRACE_UPDATE_IGNORE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) case FTRACE_UPDATE_MAKE_CALL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) old = ftrace_nop_replace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) case FTRACE_UPDATE_MODIFY_CALL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) case FTRACE_UPDATE_MAKE_NOP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) old = ftrace_call_replace(rec->ip, ftrace_get_addr_curr(rec));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) break;
^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) ret = ftrace_verify_code(rec->ip, old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) ftrace_bug(ret, rec);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) for_ftrace_rec_iter(iter) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) rec = ftrace_rec_iter_record(iter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) switch (ftrace_test_record(rec, enable)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) case FTRACE_UPDATE_IGNORE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) case FTRACE_UPDATE_MAKE_CALL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) case FTRACE_UPDATE_MODIFY_CALL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) new = ftrace_call_replace(rec->ip, ftrace_get_addr_new(rec));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) case FTRACE_UPDATE_MAKE_NOP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) new = ftrace_nop_replace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) text_poke_queue((void *)rec->ip, new, MCOUNT_INSN_SIZE, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) ftrace_update_record(rec, enable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) text_poke_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) void arch_ftrace_update_code(int command)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) ftrace_modify_all_code(command);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) int __init ftrace_dyn_arch_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) /* Currently only x86_64 supports dynamic trampolines */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) #ifdef CONFIG_X86_64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) #ifdef CONFIG_MODULES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) #include <linux/moduleloader.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) /* Module allocation simplifies allocating memory for code */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) static inline void *alloc_tramp(unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) return module_alloc(size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) static inline void tramp_free(void *tramp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) module_memfree(tramp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) /* Trampolines can only be created if modules are supported */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) static inline void *alloc_tramp(unsigned long size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) static inline void tramp_free(void *tramp) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) /* Defined as markers to the end of the ftrace default trampolines */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) extern void ftrace_regs_caller_end(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) extern void ftrace_regs_caller_ret(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) extern void ftrace_caller_end(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) extern void ftrace_caller_op_ptr(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) extern void ftrace_regs_caller_op_ptr(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) extern void ftrace_regs_caller_jmp(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) /* movq function_trace_op(%rip), %rdx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) /* 0x48 0x8b 0x15 <offset-to-ftrace_trace_op (4 bytes)> */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) #define OP_REF_SIZE 7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * The ftrace_ops is passed to the function callback. Since the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) * trampoline only services a single ftrace_ops, we can pass in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * that ops directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * The ftrace_op_code_union is used to create a pointer to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * ftrace_ops that will be passed to the callback function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) union ftrace_op_code_union {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) char code[OP_REF_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) struct {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) char op[3];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) } __attribute__((packed));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) #define RET_SIZE 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) static unsigned long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) unsigned long start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) unsigned long end_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) unsigned long op_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) unsigned long call_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) unsigned long jmp_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) unsigned long npages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) unsigned long size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) unsigned long retq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) unsigned long *ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) void *trampoline;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) void *ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) /* 48 8b 15 <offset> is movq <offset>(%rip), %rdx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) unsigned const char op_ref[] = { 0x48, 0x8b, 0x15 };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) union ftrace_op_code_union op_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) start_offset = (unsigned long)ftrace_regs_caller;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) end_offset = (unsigned long)ftrace_regs_caller_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) call_offset = (unsigned long)ftrace_regs_call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) jmp_offset = (unsigned long)ftrace_regs_caller_jmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) start_offset = (unsigned long)ftrace_caller;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) end_offset = (unsigned long)ftrace_caller_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) op_offset = (unsigned long)ftrace_caller_op_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) call_offset = (unsigned long)ftrace_call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) jmp_offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) size = end_offset - start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) * Allocate enough size to store the ftrace_caller code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * the iret , as well as the address of the ftrace_ops this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) * trampoline is used for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) trampoline = alloc_tramp(size + RET_SIZE + sizeof(void *));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) if (!trampoline)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) *tramp_size = size + RET_SIZE + sizeof(void *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) npages = DIV_ROUND_UP(*tramp_size, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) /* Copy ftrace_caller onto the trampoline memory */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) ret = copy_from_kernel_nofault(trampoline, (void *)start_offset, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) if (WARN_ON(ret < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) ip = trampoline + size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) /* The trampoline ends with ret(q) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) retq = (unsigned long)ftrace_stub;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) ret = copy_from_kernel_nofault(ip, (void *)retq, RET_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) if (WARN_ON(ret < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) /* No need to test direct calls on created trampolines */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) /* NOP the jnz 1f; but make sure it's a 2 byte jnz */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) ip = trampoline + (jmp_offset - start_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) if (WARN_ON(*(char *)ip != 0x75))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) ret = copy_from_kernel_nofault(ip, ideal_nops[2], 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) * The address of the ftrace_ops that is used for this trampoline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) * is stored at the end of the trampoline. This will be used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) * load the third parameter for the callback. Basically, that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) * location at the end of the trampoline takes the place of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) * the global function_trace_op variable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) ptr = (unsigned long *)(trampoline + size + RET_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) *ptr = (unsigned long)ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) op_offset -= start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) memcpy(&op_ptr, trampoline + op_offset, OP_REF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) /* Are we pointing to the reference? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if (WARN_ON(memcmp(op_ptr.op, op_ref, 3) != 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) /* Load the contents of ptr into the callback parameter */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) offset = (unsigned long)ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) offset -= (unsigned long)trampoline + op_offset + OP_REF_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) op_ptr.offset = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) /* put in the new offset to the ftrace_ops */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) memcpy(trampoline + op_offset, &op_ptr, OP_REF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) /* put in the call to the function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) mutex_lock(&text_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) call_offset -= start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) memcpy(trampoline + call_offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) text_gen_insn(CALL_INSN_OPCODE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) trampoline + call_offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) ftrace_ops_get_func(ops)), CALL_INSN_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) mutex_unlock(&text_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) /* ALLOC_TRAMP flags lets us know we created it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) set_vm_flush_reset_perms(trampoline);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) if (likely(system_state != SYSTEM_BOOTING))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) set_memory_ro((unsigned long)trampoline, npages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) set_memory_x((unsigned long)trampoline, npages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) return (unsigned long)trampoline;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) tramp_free(trampoline);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) void set_ftrace_ops_ro(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) struct ftrace_ops *ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) unsigned long start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) unsigned long end_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) unsigned long npages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) unsigned long size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) do_for_each_ftrace_op(ops, ftrace_ops_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) start_offset = (unsigned long)ftrace_regs_caller;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) end_offset = (unsigned long)ftrace_regs_caller_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) start_offset = (unsigned long)ftrace_caller;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) end_offset = (unsigned long)ftrace_caller_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) size = end_offset - start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) size = size + RET_SIZE + sizeof(void *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) npages = DIV_ROUND_UP(size, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) set_memory_ro((unsigned long)ops->trampoline, npages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) } while_for_each_ftrace_op(ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) static unsigned long calc_trampoline_call_offset(bool save_regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) unsigned long start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) unsigned long call_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) if (save_regs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) start_offset = (unsigned long)ftrace_regs_caller;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) call_offset = (unsigned long)ftrace_regs_call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) start_offset = (unsigned long)ftrace_caller;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) call_offset = (unsigned long)ftrace_call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) return call_offset - start_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) void arch_ftrace_update_trampoline(struct ftrace_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) ftrace_func_t func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) unsigned long ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) unsigned int size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) const char *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) if (!ops->trampoline) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) ops->trampoline = create_trampoline(ops, &size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) if (!ops->trampoline)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) ops->trampoline_size = size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) * The ftrace_ops caller may set up its own trampoline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) * In such a case, this code must not modify it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) ip = ops->trampoline + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) func = ftrace_ops_get_func(ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) mutex_lock(&text_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) /* Do a safe modify in case the trampoline is executing */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) new = ftrace_call_replace(ip, (unsigned long)func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) mutex_unlock(&text_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) /* Return the address of the function the trampoline calls */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) static void *addr_from_call(void *ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) union text_poke_insn call;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) ret = copy_from_kernel_nofault(&call, ptr, CALL_INSN_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) if (WARN_ON_ONCE(ret < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) /* Make sure this is a call */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (WARN_ON_ONCE(call.opcode != CALL_INSN_OPCODE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) pr_warn("Expected E8, got %x\n", call.opcode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) return NULL;
^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) return ptr + CALL_INSN_SIZE + call.disp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) unsigned long frame_pointer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) * If the ops->trampoline was not allocated, then it probably
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) * has a static trampoline func, or is the ftrace caller itself.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) static void *static_tramp_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) bool save_regs = rec->flags & FTRACE_FL_REGS_EN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) void *ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) if (ops && ops->trampoline) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) #ifdef CONFIG_FUNCTION_GRAPH_TRACER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) * We only know about function graph tracer setting as static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) * trampoline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) if (ops->trampoline == FTRACE_GRAPH_ADDR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) return (void *)prepare_ftrace_return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) offset = calc_trampoline_call_offset(save_regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) if (save_regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) ptr = (void *)FTRACE_REGS_ADDR + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) ptr = (void *)FTRACE_ADDR + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) return addr_from_call(ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) /* If we didn't allocate this trampoline, consider it static */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) return static_tramp_func(ops, rec);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) offset = calc_trampoline_call_offset(ops->flags & FTRACE_OPS_FL_SAVE_REGS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) return addr_from_call((void *)ops->trampoline + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) if (!ops || !(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) tramp_free((void *)ops->trampoline);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) ops->trampoline = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) #endif /* CONFIG_X86_64 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) #endif /* CONFIG_DYNAMIC_FTRACE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) #ifdef CONFIG_FUNCTION_GRAPH_TRACER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) #ifdef CONFIG_DYNAMIC_FTRACE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) extern void ftrace_graph_call(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) static const char *ftrace_jmp_replace(unsigned long ip, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) return text_gen_insn(JMP32_INSN_OPCODE, (void *)ip, (void *)addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) static int ftrace_mod_jmp(unsigned long ip, void *func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) const char *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) new = ftrace_jmp_replace(ip, (unsigned long)func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) text_poke_bp((void *)ip, new, MCOUNT_INSN_SIZE, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) int ftrace_enable_ftrace_graph_caller(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) unsigned long ip = (unsigned long)(&ftrace_graph_call);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) return ftrace_mod_jmp(ip, &ftrace_graph_caller);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) int ftrace_disable_ftrace_graph_caller(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) unsigned long ip = (unsigned long)(&ftrace_graph_call);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) return ftrace_mod_jmp(ip, &ftrace_stub);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) #endif /* !CONFIG_DYNAMIC_FTRACE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) * Hook the return address and push it in the stack of return addrs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) * in current thread info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) unsigned long frame_pointer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) unsigned long return_hooker = (unsigned long)&return_to_handler;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) unsigned long old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) int faulted;
^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) * When resuming from suspend-to-ram, this function can be indirectly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) * called from early CPU startup code while the CPU is in real mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) * which would fail miserably. Make sure the stack pointer is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) * virtual address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) * This check isn't as accurate as virt_addr_valid(), but it should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) * good enough for this purpose, and it's fast.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) if (unlikely((long)__builtin_frame_address(0) >= 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) if (unlikely(ftrace_graph_is_dead()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) if (unlikely(atomic_read(¤t->tracing_graph_pause)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) * Protect against fault, even if it shouldn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) * happen. This tool is too much intrusive to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) * ignore such a protection.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) asm volatile(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) "1: " _ASM_MOV " (%[parent]), %[old]\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) "2: " _ASM_MOV " %[return_hooker], (%[parent])\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) " movl $0, %[faulted]\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) "3:\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) ".section .fixup, \"ax\"\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) "4: movl $1, %[faulted]\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) " jmp 3b\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) ".previous\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) _ASM_EXTABLE(1b, 4b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) _ASM_EXTABLE(2b, 4b)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) : [old] "=&r" (old), [faulted] "=r" (faulted)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) : "memory"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) if (unlikely(faulted)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) ftrace_graph_stop();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) WARN_ON(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) if (function_graph_enter(old, self_addr, frame_pointer, parent))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) *parent = old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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