^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) * linux/kernel/exit.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 1991, 1992 Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/sched/autogroup.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/sched/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/sched/cputime.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/capability.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/completion.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/personality.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/tty.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/iocontext.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/key.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/acct.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/tsacct_kern.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/fdtable.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/freezer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/binfmts.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/nsproxy.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/pid_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/profile.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/proc_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/kthread.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/mempolicy.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/taskstats_kern.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/delayacct.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <linux/cgroup.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <linux/syscalls.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <linux/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <linux/posix-timers.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <linux/cn_proc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include <linux/futex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/pipe_fs_i.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <linux/audit.h> /* for audit_free() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <linux/resource.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #include <linux/blkdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #include <linux/task_io_accounting_ops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #include <linux/tracehook.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #include <linux/fs_struct.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) #include <linux/init_task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) #include <linux/perf_event.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #include <trace/events/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #include <linux/hw_breakpoint.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) #include <linux/oom.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) #include <linux/writeback.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) #include <linux/shm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) #include <linux/kcov.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) #include <linux/random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) #include <linux/rcuwait.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) #include <linux/compat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) #include <linux/io_uring.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) #include <asm/unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) #include <asm/mmu_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) #include <trace/hooks/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) static void __unhash_process(struct task_struct *p, bool group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) nr_threads--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) detach_pid(p, PIDTYPE_PID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (group_dead) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) detach_pid(p, PIDTYPE_TGID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) detach_pid(p, PIDTYPE_PGID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) detach_pid(p, PIDTYPE_SID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) list_del_rcu(&p->tasks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) list_del_init(&p->sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) __this_cpu_dec(process_counts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) list_del_rcu(&p->thread_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) list_del_rcu(&p->thread_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * This function expects the tasklist_lock write-locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static void __exit_signal(struct task_struct *tsk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) struct signal_struct *sig = tsk->signal;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) bool group_dead = thread_group_leader(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) struct sighand_struct *sighand;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) struct tty_struct *tty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) u64 utime, stime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) sighand = rcu_dereference_check(tsk->sighand,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) lockdep_tasklist_lock_is_held());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) spin_lock(&sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) #ifdef CONFIG_POSIX_TIMERS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) posix_cpu_timers_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) posix_cpu_timers_exit_group(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (group_dead) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) tty = sig->tty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) sig->tty = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * If there is any task waiting for the group exit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) * then notify it:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) if (sig->notify_count > 0 && !--sig->notify_count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) wake_up_process(sig->group_exit_task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (tsk == sig->curr_target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) sig->curr_target = next_thread(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) sizeof(unsigned long long));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * Accumulate here the counters for all threads as they die. We could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) * skip the group leader because it is the last user of signal_struct,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) * but we want to avoid the race with thread_group_cputime() which can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) * see the empty ->thread_head list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) task_cputime(tsk, &utime, &stime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) write_seqlock(&sig->stats_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) sig->utime += utime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) sig->stime += stime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) sig->gtime += task_gtime(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) sig->min_flt += tsk->min_flt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) sig->maj_flt += tsk->maj_flt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) sig->nvcsw += tsk->nvcsw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) sig->nivcsw += tsk->nivcsw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) sig->inblock += task_io_get_inblock(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) sig->oublock += task_io_get_oublock(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) task_io_accounting_add(&sig->ioac, &tsk->ioac);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) sig->nr_threads--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) __unhash_process(tsk, group_dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) write_sequnlock(&sig->stats_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * Do this under ->siglock, we can race with another thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) flush_sigqueue(&tsk->pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) tsk->sighand = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) spin_unlock(&sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) __cleanup_sighand(sighand);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) if (group_dead) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) flush_sigqueue(&sig->shared_pending);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) tty_kref_put(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) static void delayed_put_task_struct(struct rcu_head *rhp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) perf_event_delayed_put(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) trace_sched_process_free(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) put_task_struct(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) void put_task_struct_rcu_user(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) if (refcount_dec_and_test(&task->rcu_users))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) call_rcu(&task->rcu, delayed_put_task_struct);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) void release_task(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) struct task_struct *leader;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) struct pid *thread_pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) int zap_leader;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) repeat:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) /* don't need to get the RCU readlock here - the process is dead and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * can't be modifying its own credentials. But shut RCU-lockdep up */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) atomic_dec(&__task_cred(p)->user->processes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) cgroup_release(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) write_lock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) ptrace_release_task(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) thread_pid = get_pid(p->thread_pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) __exit_signal(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) * If we are the last non-leader member of the thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) * group, and the leader is zombie, then notify the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) * group leader's parent process. (if it wants notification.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) zap_leader = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) leader = p->group_leader;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) if (leader != p && thread_group_empty(leader)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) && leader->exit_state == EXIT_ZOMBIE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) * If we were the last child thread and the leader has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) * exited already, and the leader's parent ignores SIGCHLD,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) * then we are the one who should release the leader.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) zap_leader = do_notify_parent(leader, leader->exit_signal);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) if (zap_leader)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) leader->exit_state = EXIT_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) write_unlock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) seccomp_filter_release(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) proc_flush_pid(thread_pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) put_pid(thread_pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) release_thread(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) put_task_struct_rcu_user(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) p = leader;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) if (unlikely(zap_leader))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) goto repeat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) int rcuwait_wake_up(struct rcuwait *w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) * Order condition vs @task, such that everything prior to the load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) * of @task is visible. This is the condition as to why the user called
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) * rcuwait_wake() in the first place. Pairs with set_current_state()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) * barrier (A) in rcuwait_wait_event().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) * WAIT WAKE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) * [S] tsk = current [S] cond = true
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) * MB (A) MB (B)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) * [L] cond [L] tsk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) smp_mb(); /* (B) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) task = rcu_dereference(w->task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) if (task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) ret = wake_up_process(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) EXPORT_SYMBOL_GPL(rcuwait_wake_up);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) * Determine if a process group is "orphaned", according to the POSIX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) * definition in 2.2.2.52. Orphaned process groups are not to be affected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * by terminal-generated stop signals. Newly orphaned process groups are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * to receive a SIGHUP and a SIGCONT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) * "I ask you, have you ever known what it is to be an orphan?"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) static int will_become_orphaned_pgrp(struct pid *pgrp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) struct task_struct *ignored_task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) struct task_struct *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) if ((p == ignored_task) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) (p->exit_state && thread_group_empty(p)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) is_global_init(p->real_parent))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) if (task_pgrp(p->real_parent) != pgrp &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) task_session(p->real_parent) == task_session(p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) int is_current_pgrp_orphaned(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) read_lock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) retval = will_become_orphaned_pgrp(task_pgrp(current), NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) static bool has_stopped_jobs(struct pid *pgrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) struct task_struct *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) if (p->signal->flags & SIGNAL_STOP_STOPPED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) * Check to see if any process groups have become orphaned as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * a result of our exiting, and if they have any stopped jobs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) struct pid *pgrp = task_pgrp(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) struct task_struct *ignored_task = tsk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (!parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) /* exit: our father is in a different pgrp than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * we are and we were the only connection outside.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) parent = tsk->real_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) /* reparent: our child is in a different pgrp than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) * we are, and it was the only connection outside.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) ignored_task = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) if (task_pgrp(parent) != pgrp &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) task_session(parent) == task_session(tsk) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) will_become_orphaned_pgrp(pgrp, ignored_task) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) has_stopped_jobs(pgrp)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
^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)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) #ifdef CONFIG_MEMCG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * A task is exiting. If it owned this mm, find a new owner for the mm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) void mm_update_next_owner(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) struct task_struct *c, *g, *p = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) retry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * If the exiting or execing task is not the owner, it's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) * someone else's problem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) if (mm->owner != p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) * The current owner is exiting/execing and there are no other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * candidates. Do not leave the mm pointing to a possibly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) * freed task structure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) if (atomic_read(&mm->mm_users) <= 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) WRITE_ONCE(mm->owner, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) read_lock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) * Search in the children
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) list_for_each_entry(c, &p->children, sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) if (c->mm == mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) goto assign_new_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) * Search in the siblings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) list_for_each_entry(c, &p->real_parent->children, sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) if (c->mm == mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) goto assign_new_owner;
^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) * Search through everything else, we should not get here often.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) for_each_process(g) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) if (g->flags & PF_KTHREAD)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) for_each_thread(g, c) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) if (c->mm == mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) goto assign_new_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) if (c->mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) * We found no owner yet mm_users > 1: this implies that we are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * most likely racing with swapoff (try_to_unuse()) or /proc or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * ptrace or page migration (get_task_mm()). Mark owner as NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) WRITE_ONCE(mm->owner, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) assign_new_owner:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) BUG_ON(c == p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) get_task_struct(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) * The task_lock protects c->mm from changing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * We always want mm->owner->mm == mm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) task_lock(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * Delay read_unlock() till we have the task_lock()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * to ensure that c does not slip away underneath us
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) if (c->mm != mm) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) task_unlock(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) put_task_struct(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) WRITE_ONCE(mm->owner, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) task_unlock(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) put_task_struct(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) #endif /* CONFIG_MEMCG */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) * Turn us into a lazy TLB process if we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) * aren't already..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) static void exit_mm(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) struct mm_struct *mm = current->mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) struct core_state *core_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) exit_mm_release(current, mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) if (!mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) sync_mm_rss(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * Serialize with any possible pending coredump.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * We must hold mmap_lock around checking core_state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * and clearing tsk->mm. The core-inducing thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * will increment ->nr_threads for each thread in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * group with ->mm != NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) mmap_read_lock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) core_state = mm->core_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) if (core_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) struct core_thread self;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) self.task = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) if (self.task->flags & PF_SIGNALED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) self.next = xchg(&core_state->dumper.next, &self);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) self.task = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) * Implies mb(), the result of xchg() must be visible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) * to core_state->dumper.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) if (atomic_dec_and_test(&core_state->nr_threads))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) complete(&core_state->startup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) set_current_state(TASK_UNINTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) if (!self.task) /* see coredump_finish() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) freezable_schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) __set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) mmap_read_lock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) mmgrab(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) BUG_ON(mm != current->active_mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) /* more a memory barrier than a real lock */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) task_lock(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) current->mm = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) enter_lazy_tlb(mm, current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) task_unlock(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) mm_update_next_owner(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) trace_android_vh_exit_mm(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) mmput(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) if (test_thread_flag(TIF_MEMDIE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) exit_oom_victim();
^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) static struct task_struct *find_alive_thread(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) struct task_struct *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) for_each_thread(p, t) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) if (!(t->flags & PF_EXITING))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) return t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) static struct task_struct *find_child_reaper(struct task_struct *father,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) struct list_head *dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) __releases(&tasklist_lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) __acquires(&tasklist_lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) struct pid_namespace *pid_ns = task_active_pid_ns(father);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) struct task_struct *reaper = pid_ns->child_reaper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) struct task_struct *p, *n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) if (likely(reaper != father))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) return reaper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) reaper = find_alive_thread(father);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) if (reaper) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) pid_ns->child_reaper = reaper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) return reaper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) write_unlock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) list_for_each_entry_safe(p, n, dead, ptrace_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) list_del_init(&p->ptrace_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) release_task(p);
^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) zap_pid_ns_processes(pid_ns);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) write_lock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) return father;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) * When we die, we re-parent all our children, and try to:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) * 1. give them to another thread in our thread group, if such a member exists
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) * 2. give it to the first ancestor process which prctl'd itself as a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) * child_subreaper for its children (like a service manager)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) * 3. give it to the init process (PID 1) in our pid namespace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) static struct task_struct *find_new_reaper(struct task_struct *father,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) struct task_struct *child_reaper)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) struct task_struct *thread, *reaper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) thread = find_alive_thread(father);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) if (thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) return thread;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) if (father->signal->has_child_subreaper) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) unsigned int ns_level = task_pid(father)->level;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) * Find the first ->is_child_subreaper ancestor in our pid_ns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) * We can't check reaper != child_reaper to ensure we do not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) * cross the namespaces, the exiting parent could be injected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) * by setns() + fork().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) * We check pid->level, this is slightly more efficient than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) * task_active_pid_ns(reaper) != task_active_pid_ns(father).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) for (reaper = father->real_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) task_pid(reaper)->level == ns_level;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) reaper = reaper->real_parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if (reaper == &init_task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) if (!reaper->signal->is_child_subreaper)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) thread = find_alive_thread(reaper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) if (thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) return thread;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) return child_reaper;
^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) * Any that need to be release_task'd are put on the @dead list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) static void reparent_leader(struct task_struct *father, struct task_struct *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) struct list_head *dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) if (unlikely(p->exit_state == EXIT_DEAD))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) /* We don't want people slaying init. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) p->exit_signal = SIGCHLD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) /* If it has exited notify the new parent about this child's death. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) if (!p->ptrace &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) if (do_notify_parent(p, p->exit_signal)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) p->exit_state = EXIT_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) list_add(&p->ptrace_entry, dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) }
^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) kill_orphaned_pgrp(p, father);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) * This does two things:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) * A. Make init inherit all the child processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) * B. Check to see if any process groups have become orphaned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) * as a result of our exiting, and if they have any stopped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) static void forget_original_parent(struct task_struct *father,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) struct list_head *dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) struct task_struct *p, *t, *reaper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) if (unlikely(!list_empty(&father->ptraced)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) exit_ptrace(father, dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) /* Can drop and reacquire tasklist_lock */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) reaper = find_child_reaper(father, dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) if (list_empty(&father->children))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) reaper = find_new_reaper(father, reaper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) list_for_each_entry(p, &father->children, sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) for_each_thread(p, t) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) RCU_INIT_POINTER(t->real_parent, reaper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) BUG_ON((!t->ptrace) != (rcu_access_pointer(t->parent) == father));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) if (likely(!t->ptrace))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) t->parent = t->real_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) if (t->pdeath_signal)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) group_send_sig_info(t->pdeath_signal,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) SEND_SIG_NOINFO, t,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) PIDTYPE_TGID);
^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) * If this is a threaded reparent there is no need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) * notify anyone anything has happened.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) if (!same_thread_group(reaper, father))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) reparent_leader(father, p, dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) list_splice_tail_init(&father->children, &reaper->children);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) * Send signals to all our closest relatives so that they know
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) * to properly mourn us..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) static void exit_notify(struct task_struct *tsk, int group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) bool autoreap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) struct task_struct *p, *n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) LIST_HEAD(dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) write_lock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) forget_original_parent(tsk, &dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) if (group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) kill_orphaned_pgrp(tsk->group_leader, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) tsk->exit_state = EXIT_ZOMBIE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) if (unlikely(tsk->ptrace)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) int sig = thread_group_leader(tsk) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) thread_group_empty(tsk) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) !ptrace_reparented(tsk) ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) tsk->exit_signal : SIGCHLD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) autoreap = do_notify_parent(tsk, sig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) } else if (thread_group_leader(tsk)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) autoreap = thread_group_empty(tsk) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) do_notify_parent(tsk, tsk->exit_signal);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) autoreap = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) if (autoreap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) tsk->exit_state = EXIT_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) list_add(&tsk->ptrace_entry, &dead);
^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) /* mt-exec, de_thread() is waiting for group leader */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) if (unlikely(tsk->signal->notify_count < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) wake_up_process(tsk->signal->group_exit_task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) write_unlock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) list_for_each_entry_safe(p, n, &dead, ptrace_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) list_del_init(&p->ptrace_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) release_task(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) #ifdef CONFIG_DEBUG_STACK_USAGE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) static void check_stack_usage(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) static DEFINE_SPINLOCK(low_water_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) static int lowest_to_date = THREAD_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) unsigned long free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) free = stack_not_used(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) if (free >= lowest_to_date)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) spin_lock(&low_water_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) if (free < lowest_to_date) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) pr_info("%s (%d) used greatest stack depth: %lu bytes left\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) current->comm, task_pid_nr(current), free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) lowest_to_date = free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) spin_unlock(&low_water_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) static inline void check_stack_usage(void) {}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) void __noreturn do_exit(long code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) struct task_struct *tsk = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) int group_dead;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) * We can get here from a kernel oops, sometimes with preemption off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) * Start by checking for critical errors.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) * Then fix up important state like USER_DS and preemption.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) * Then do everything else.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) WARN_ON(blk_needs_flush_plug(tsk));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (unlikely(in_interrupt()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) panic("Aiee, killing interrupt handler!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) if (unlikely(!tsk->pid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) panic("Attempted to kill the idle task!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) * If do_exit is called because this processes oopsed, it's possible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) * continuing. Amongst other possible reasons, this is to prevent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) * mm_release()->clear_child_tid() from writing to a user-controlled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) * kernel address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) force_uaccess_begin();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) if (unlikely(in_atomic())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) pr_info("note: %s[%d] exited with preempt_count %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) current->comm, task_pid_nr(current),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) preempt_count());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) preempt_count_set(PREEMPT_ENABLED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) profile_task_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) kcov_task_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) ptrace_event(PTRACE_EVENT_EXIT, code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) validate_creds_for_do_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) * We're taking recursive faults here in do_exit. Safest is to just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) * leave this task alone and wait for reboot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) if (unlikely(tsk->flags & PF_EXITING)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) pr_alert("Fixing recursive fault but reboot is needed!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) futex_exit_recursive(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) set_current_state(TASK_UNINTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) schedule();
^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) io_uring_files_cancel(tsk->files);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) exit_signals(tsk); /* sets PF_EXITING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) /* sync mm's RSS info before statistics gathering */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) if (tsk->mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) sync_mm_rss(tsk->mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) acct_update_integrals(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) group_dead = atomic_dec_and_test(&tsk->signal->live);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) if (group_dead) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) * If the last thread of global init has exited, panic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) * immediately to get a useable coredump.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) if (unlikely(is_global_init(tsk)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) panic("Attempted to kill init! exitcode=0x%08x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) tsk->signal->group_exit_code ?: (int)code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) #ifdef CONFIG_POSIX_TIMERS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) hrtimer_cancel(&tsk->signal->real_timer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) exit_itimers(tsk->signal);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) if (tsk->mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) acct_collect(code, group_dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) if (group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) tty_audit_exit();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) audit_free(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) tsk->exit_code = code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) taskstats_exit(tsk, group_dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) exit_mm();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) if (group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) acct_process();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) trace_sched_process_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) exit_sem(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) exit_shm(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) exit_files(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) exit_fs(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) if (group_dead)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) disassociate_ctty(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) exit_task_namespaces(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) exit_task_work(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) exit_thread(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) * Flush inherited counters to the parent - before the parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) * gets woken up by child-exit notifications.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) * because of cgroup mode, must be called before cgroup_exit()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) perf_event_exit_task(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) sched_autogroup_exit_task(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) cgroup_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) * FIXME: do that only when needed, using sched_exit tracepoint
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) flush_ptrace_hw_breakpoint(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) exit_tasks_rcu_start();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) exit_notify(tsk, group_dead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) proc_exit_connector(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) mpol_put_task_policy(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) #ifdef CONFIG_FUTEX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) if (unlikely(current->pi_state_cache))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) kfree(current->pi_state_cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) * Make sure we are holding no locks:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) debug_check_no_locks_held();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) if (tsk->io_context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) exit_io_context(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) if (tsk->splice_pipe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) free_pipe_info(tsk->splice_pipe);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) if (tsk->task_frag.page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) put_page(tsk->task_frag.page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) validate_creds_for_do_exit(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) check_stack_usage();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) if (tsk->nr_dirtied)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) exit_rcu();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) exit_tasks_rcu_finish();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) lockdep_free_task(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) do_task_dead();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) EXPORT_SYMBOL_GPL(do_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) void complete_and_exit(struct completion *comp, long code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) if (comp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) complete(comp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) do_exit(code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) EXPORT_SYMBOL(complete_and_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) SYSCALL_DEFINE1(exit, int, error_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) do_exit((error_code&0xff)<<8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) }
^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) * Take down every thread in the group. This is called by fatal signals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) * as well as by sys_exit_group (below).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) do_group_exit(int exit_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) struct signal_struct *sig = current->signal;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) BUG_ON(exit_code & 0x80); /* core dumps don't get here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) if (signal_group_exit(sig))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) exit_code = sig->group_exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) else if (!thread_group_empty(current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) struct sighand_struct *const sighand = current->sighand;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) spin_lock_irq(&sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) if (signal_group_exit(sig))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) /* Another thread got here before we took the lock. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) exit_code = sig->group_exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) sig->group_exit_code = exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) sig->flags = SIGNAL_GROUP_EXIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) zap_other_threads(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) spin_unlock_irq(&sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) do_exit(exit_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) /* NOTREACHED */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) * this kills every thread in the thread group. Note that any externally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) * wait4()-ing process will get the correct exit code - even if this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) * thread is not the thread group leader.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) SYSCALL_DEFINE1(exit_group, int, error_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) do_group_exit((error_code & 0xff) << 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) /* NOTREACHED */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) struct waitid_info {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) pid_t pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) uid_t uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) int cause;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) struct wait_opts {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) enum pid_type wo_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) int wo_flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) struct pid *wo_pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) struct waitid_info *wo_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) int wo_stat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) struct rusage *wo_rusage;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) wait_queue_entry_t child_wait;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) int notask_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) return wo->wo_type == PIDTYPE_MAX ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) task_pid_type(p, wo->wo_type) == wo->wo_pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) if (!eligible_pid(wo, p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) return 0;
^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) * Wait for all children (clone and not) if __WALL is set or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) * if it is traced by us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) if (ptrace || (wo->wo_flags & __WALL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) * Otherwise, wait for clone children *only* if __WCLONE is set;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) * otherwise, wait for non-clone children *only*.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) * Note: a "clone" child here is one that reports to its parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) * using a signal other than SIGCHLD, or a non-leader thread which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) * we can only see if it is traced by us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) * the lock and this task is uninteresting. If we return nonzero, we have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) * released the lock and the system call should return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) int state, status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) pid_t pid = task_pid_vnr(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) struct waitid_info *infop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) if (!likely(wo->wo_flags & WEXITED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) if (unlikely(wo->wo_flags & WNOWAIT)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) status = p->exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) get_task_struct(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) sched_annotate_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) if (wo->wo_rusage)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) put_task_struct(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) goto out_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) * Move the task's state to DEAD/TRACE, only one thread can do this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) state = (ptrace_reparented(p) && thread_group_leader(p)) ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) EXIT_TRACE : EXIT_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) * We own this thread, nobody else can reap it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) sched_annotate_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) * Check thread_group_leader() to exclude the traced sub-threads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) if (state == EXIT_DEAD && thread_group_leader(p)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) struct signal_struct *sig = p->signal;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) struct signal_struct *psig = current->signal;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) unsigned long maxrss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) u64 tgutime, tgstime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) * The resource counters for the group leader are in its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) * own task_struct. Those for dead threads in the group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) * are in its signal_struct, as are those for the child
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) * processes it has previously reaped. All these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) * accumulate in the parent's signal_struct c* fields.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) * We don't bother to take a lock here to protect these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) * p->signal fields because the whole thread group is dead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) * and nobody can change them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) * psig->stats_lock also protects us from our sub-theads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) * which can reap other children at the same time. Until
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) * we change k_getrusage()-like users to rely on this lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) * we have to take ->siglock as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) * We use thread_group_cputime_adjusted() to get times for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) * the thread group, which consolidates times for all threads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) * in the group including the group leader.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) thread_group_cputime_adjusted(p, &tgutime, &tgstime);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) spin_lock_irq(¤t->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) write_seqlock(&psig->stats_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) psig->cutime += tgutime + sig->cutime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) psig->cstime += tgstime + sig->cstime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) psig->cmin_flt +=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) p->min_flt + sig->min_flt + sig->cmin_flt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) psig->cmaj_flt +=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) p->maj_flt + sig->maj_flt + sig->cmaj_flt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) psig->cnvcsw +=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) p->nvcsw + sig->nvcsw + sig->cnvcsw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) psig->cnivcsw +=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) p->nivcsw + sig->nivcsw + sig->cnivcsw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) psig->cinblock +=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) task_io_get_inblock(p) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) sig->inblock + sig->cinblock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) psig->coublock +=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) task_io_get_oublock(p) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) sig->oublock + sig->coublock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) maxrss = max(sig->maxrss, sig->cmaxrss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) if (psig->cmaxrss < maxrss)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) psig->cmaxrss = maxrss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) task_io_accounting_add(&psig->ioac, &p->ioac);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) task_io_accounting_add(&psig->ioac, &sig->ioac);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) write_sequnlock(&psig->stats_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) spin_unlock_irq(¤t->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) if (wo->wo_rusage)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) status = (p->signal->flags & SIGNAL_GROUP_EXIT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) ? p->signal->group_exit_code : p->exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) wo->wo_stat = status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) if (state == EXIT_TRACE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) write_lock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) /* We dropped tasklist, ptracer could die and untrace */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) ptrace_unlink(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) /* If parent wants a zombie, don't release it now */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) state = EXIT_ZOMBIE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) if (do_notify_parent(p, p->exit_signal))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) state = EXIT_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) p->exit_state = state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) write_unlock_irq(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) if (state == EXIT_DEAD)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) release_task(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) out_info:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) infop = wo->wo_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) if (infop) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) if ((status & 0x7f) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) infop->cause = CLD_EXITED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) infop->status = status >> 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) infop->status = status & 0x7f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) infop->pid = pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) infop->uid = uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) return pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) static int *task_stopped_code(struct task_struct *p, bool ptrace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) if (ptrace) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) if (task_is_traced(p) && !(p->jobctl & JOBCTL_LISTENING))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) return &p->exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) if (p->signal->flags & SIGNAL_STOP_STOPPED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) return &p->signal->group_exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) * wait_task_stopped - Wait for %TASK_STOPPED or %TASK_TRACED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) * @wo: wait options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) * @ptrace: is the wait for ptrace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) * @p: task to wait for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) * Handle sys_wait4() work for %p in state %TASK_STOPPED or %TASK_TRACED.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) * CONTEXT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) * read_lock(&tasklist_lock), which is released if return value is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) * non-zero. Also, grabs and releases @p->sighand->siglock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) * RETURNS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) * 0 if wait condition didn't exist and search for other wait conditions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) * should continue. Non-zero return, -errno on failure and @p's pid on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) * success, implies that tasklist_lock is released and wait condition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) * search should terminate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) static int wait_task_stopped(struct wait_opts *wo,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) int ptrace, struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) struct waitid_info *infop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) int exit_code, *p_code, why;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) uid_t uid = 0; /* unneeded, required by compiler */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) pid_t pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) * Traditionally we see ptrace'd stopped tasks regardless of options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) if (!ptrace && !(wo->wo_flags & WUNTRACED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) if (!task_stopped_code(p, ptrace))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) exit_code = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) spin_lock_irq(&p->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) p_code = task_stopped_code(p, ptrace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) if (unlikely(!p_code))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) goto unlock_sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) exit_code = *p_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) if (!exit_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) goto unlock_sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) if (!unlikely(wo->wo_flags & WNOWAIT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) *p_code = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) uid = from_kuid_munged(current_user_ns(), task_uid(p));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) unlock_sig:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) spin_unlock_irq(&p->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) if (!exit_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) * Now we are pretty sure this task is interesting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) * Make sure it doesn't get reaped out from under us while we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) * give up the lock and then examine it below. We don't want to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) * keep holding onto the tasklist_lock while we call getrusage and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) * possibly take page faults for user memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) get_task_struct(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) pid = task_pid_vnr(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) sched_annotate_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) if (wo->wo_rusage)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) put_task_struct(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) if (likely(!(wo->wo_flags & WNOWAIT)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) wo->wo_stat = (exit_code << 8) | 0x7f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) infop = wo->wo_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) if (infop) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) infop->cause = why;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) infop->status = exit_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) infop->pid = pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) infop->uid = uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) return pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) * Handle do_wait work for one task in a live, non-stopped state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) * the lock and this task is uninteresting. If we return nonzero, we have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) * released the lock and the system call should return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) struct waitid_info *infop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) pid_t pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) uid_t uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) if (!unlikely(wo->wo_flags & WCONTINUED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) spin_lock_irq(&p->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) /* Re-check with the lock held. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) spin_unlock_irq(&p->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) if (!unlikely(wo->wo_flags & WNOWAIT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) uid = from_kuid_munged(current_user_ns(), task_uid(p));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) spin_unlock_irq(&p->sighand->siglock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) pid = task_pid_vnr(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) get_task_struct(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) sched_annotate_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) if (wo->wo_rusage)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) put_task_struct(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) infop = wo->wo_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) if (!infop) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) wo->wo_stat = 0xffff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) infop->cause = CLD_CONTINUED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) infop->pid = pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) infop->uid = uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) infop->status = SIGCONT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) return pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) * Consider @p for a wait by @parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) * -ECHILD should be in ->notask_error before the first call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) * Returns nonzero for a final return, when we have unlocked tasklist_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) * Returns zero if the search for a child should continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) * then ->notask_error is 0 if @p is an eligible child,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) * or still -ECHILD.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) static int wait_consider_task(struct wait_opts *wo, int ptrace,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) * We can race with wait_task_zombie() from another thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) * can't confuse the checks below.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) int exit_state = READ_ONCE(p->exit_state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) if (unlikely(exit_state == EXIT_DEAD))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) ret = eligible_child(wo, ptrace, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) if (unlikely(exit_state == EXIT_TRACE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) * ptrace == 0 means we are the natural parent. In this case
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) * we should clear notask_error, debugger will notify us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) if (likely(!ptrace))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) wo->notask_error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) if (likely(!ptrace) && unlikely(p->ptrace)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) * If it is traced by its real parent's group, just pretend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) * the caller is ptrace_do_wait() and reap this child if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) * is zombie.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) * This also hides group stop state from real parent; otherwise
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) * a single stop can be reported twice as group and ptrace stop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) * If a ptracer wants to distinguish these two events for its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) * own children it should create a separate process which takes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) * the role of real parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) if (!ptrace_reparented(p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) ptrace = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) /* slay zombie? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) if (exit_state == EXIT_ZOMBIE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) /* we don't reap group leaders with subthreads */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) if (!delay_group_leader(p)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) * A zombie ptracee is only visible to its ptracer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) * Notification and reaping will be cascaded to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) * real parent when the ptracer detaches.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) if (unlikely(ptrace) || likely(!p->ptrace))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) return wait_task_zombie(wo, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) * Allow access to stopped/continued state via zombie by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) * falling through. Clearing of notask_error is complex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) * When !@ptrace:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) * If WEXITED is set, notask_error should naturally be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) * cleared. If not, subset of WSTOPPED|WCONTINUED is set,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) * so, if there are live subthreads, there are events to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) * wait for. If all subthreads are dead, it's still safe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) * to clear - this function will be called again in finite
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) * amount time once all the subthreads are released and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) * will then return without clearing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) * When @ptrace:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) * Stopped state is per-task and thus can't change once the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) * target task dies. Only continued and exited can happen.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) * Clear notask_error if WCONTINUED | WEXITED.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) if (likely(!ptrace) || (wo->wo_flags & (WCONTINUED | WEXITED)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) wo->notask_error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) * @p is alive and it's gonna stop, continue or exit, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) * there always is something to wait for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) wo->notask_error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) * Wait for stopped. Depending on @ptrace, different stopped state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) * is used and the two don't interact with each other.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) ret = wait_task_stopped(wo, ptrace, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) * Wait for continued. There's only one continued state and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) * ptracer can consume it which can confuse the real parent. Don't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) * use WCONTINUED from ptracer. You don't need or want it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) return wait_task_continued(wo, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) * Do the work of do_wait() for one thread in the group, @tsk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) * -ECHILD should be in ->notask_error before the first call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) * Returns nonzero for a final return, when we have unlocked tasklist_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) * Returns zero if the search for a child should continue; then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) * ->notask_error is 0 if there were any eligible children,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) * or still -ECHILD.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) struct task_struct *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) list_for_each_entry(p, &tsk->children, sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) int ret = wait_consider_task(wo, 0, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) struct task_struct *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) int ret = wait_consider_task(wo, 1, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) static int child_wait_callback(wait_queue_entry_t *wait, unsigned mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) int sync, void *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) struct wait_opts *wo = container_of(wait, struct wait_opts,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) child_wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) struct task_struct *p = key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) if (!eligible_pid(wo, p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) return default_wake_function(wait, mode, sync, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) __wake_up_sync_key(&parent->signal->wait_chldexit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) TASK_INTERRUPTIBLE, p);
^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 long do_wait(struct wait_opts *wo)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) struct task_struct *tsk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) trace_sched_process_wait(wo->wo_pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) wo->child_wait.private = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) add_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) repeat:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) * If there is nothing that can match our criteria, just get out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) * We will clear ->notask_error to zero if we see any child that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) * might later match our criteria, even if we are not able to reap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) * it yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) wo->notask_error = -ECHILD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) if ((wo->wo_type < PIDTYPE_MAX) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) (!wo->wo_pid || !pid_has_task(wo->wo_pid, wo->wo_type)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) goto notask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) set_current_state(TASK_INTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) read_lock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) tsk = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) retval = do_wait_thread(wo, tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) goto end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) retval = ptrace_do_wait(wo, tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) goto end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) if (wo->wo_flags & __WNOTHREAD)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) } while_each_thread(current, tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) read_unlock(&tasklist_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) notask:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) retval = wo->notask_error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) if (!retval && !(wo->wo_flags & WNOHANG)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) retval = -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) if (!signal_pending(current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) goto repeat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) end:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) __set_current_state(TASK_RUNNING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) int options, struct rusage *ru)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) struct wait_opts wo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) struct pid *pid = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) enum pid_type type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) unsigned int f_flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) __WNOTHREAD|__WCLONE|__WALL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) switch (which) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) case P_ALL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) type = PIDTYPE_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) case P_PID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504) type = PIDTYPE_PID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) if (upid <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) pid = find_get_pid(upid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) case P_PGID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) type = PIDTYPE_PGID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) if (upid < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) if (upid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) pid = find_get_pid(upid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) pid = get_task_pid(current, PIDTYPE_PGID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) case P_PIDFD:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) type = PIDTYPE_PID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) if (upid < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) pid = pidfd_get_pid(upid, &f_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) if (IS_ERR(pid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) return PTR_ERR(pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) wo.wo_type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) wo.wo_pid = pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) wo.wo_flags = options;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) wo.wo_info = infop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) wo.wo_rusage = ru;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) if (f_flags & O_NONBLOCK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) wo.wo_flags |= WNOHANG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) ret = do_wait(&wo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) if (!ret && !(options & WNOHANG) && (f_flags & O_NONBLOCK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) ret = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) put_pid(pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) return ret;
^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) SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) infop, int, options, struct rusage __user *, ru)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) struct rusage r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) struct waitid_info info = {.status = 0};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) int signo = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) if (err > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) signo = SIGCHLD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) if (!infop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) if (!user_write_access_begin(infop, sizeof(*infop)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) unsafe_put_user(signo, &infop->si_signo, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) unsafe_put_user(0, &infop->si_errno, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) unsafe_put_user(info.cause, &infop->si_code, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573) unsafe_put_user(info.pid, &infop->si_pid, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) unsafe_put_user(info.uid, &infop->si_uid, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) unsafe_put_user(info.status, &infop->si_status, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) user_write_access_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) Efault:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579) user_write_access_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) struct rusage *ru)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) struct wait_opts wo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) struct pid *pid = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) enum pid_type type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) __WNOTHREAD|__WCLONE|__WALL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) /* -INT_MIN is not defined */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) if (upid == INT_MIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) return -ESRCH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) if (upid == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) type = PIDTYPE_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) else if (upid < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) type = PIDTYPE_PGID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) pid = find_get_pid(-upid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) } else if (upid == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) type = PIDTYPE_PGID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) pid = get_task_pid(current, PIDTYPE_PGID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) } else /* upid > 0 */ {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) type = PIDTYPE_PID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) pid = find_get_pid(upid);
^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) wo.wo_type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) wo.wo_pid = pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) wo.wo_flags = options | WEXITED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) wo.wo_info = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) wo.wo_stat = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) wo.wo_rusage = ru;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) ret = do_wait(&wo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) put_pid(pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620) if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) ret = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) int kernel_wait(pid_t pid, int *stat)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) struct wait_opts wo = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) .wo_type = PIDTYPE_PID,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) .wo_pid = find_get_pid(pid),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) .wo_flags = WEXITED,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) ret = do_wait(&wo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) if (ret > 0 && wo.wo_stat)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) *stat = wo.wo_stat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) put_pid(wo.wo_pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) int, options, struct rusage __user *, ru)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) struct rusage r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) if (err > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) #ifdef __ARCH_WANT_SYS_WAITPID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) * sys_waitpid() remains for compatibility. waitpid() should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) * implemented by calling sys_wait4() from libc.a.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) return kernel_wait4(pid, stat_addr, options, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) COMPAT_SYSCALL_DEFINE4(wait4,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) compat_pid_t, pid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) compat_uint_t __user *, stat_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) int, options,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) struct compat_rusage __user *, ru)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) struct rusage r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) if (err > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) if (ru && put_compat_rusage(&r, ru))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) COMPAT_SYSCALL_DEFINE5(waitid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) int, which, compat_pid_t, pid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) struct compat_siginfo __user *, infop, int, options,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) struct compat_rusage __user *, uru)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) struct rusage ru;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) struct waitid_info info = {.status = 0};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) int signo = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) if (err > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) signo = SIGCHLD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) if (uru) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) /* kernel_waitid() overwrites everything in ru */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) if (COMPAT_USE_64BIT_TIME)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) err = copy_to_user(uru, &ru, sizeof(ru));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) err = put_compat_rusage(&ru, uru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) if (!infop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) if (!user_write_access_begin(infop, sizeof(*infop)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) unsafe_put_user(signo, &infop->si_signo, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) unsafe_put_user(0, &infop->si_errno, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) unsafe_put_user(info.cause, &infop->si_code, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) unsafe_put_user(info.pid, &infop->si_pid, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) unsafe_put_user(info.uid, &infop->si_uid, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) unsafe_put_user(info.status, &infop->si_status, Efault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) user_write_access_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) Efault:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) user_write_access_end();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) * thread_group_exited - check that a thread group has exited
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) * @pid: tgid of thread group to be checked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) * Test if the thread group represented by tgid has exited (all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) * threads are zombies, dead or completely gone).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) * Return: true if the thread group has exited. false otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) bool thread_group_exited(struct pid *pid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) bool exited;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) task = pid_task(pid, PIDTYPE_PID);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) exited = !task ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) (READ_ONCE(task->exit_state) && thread_group_empty(task));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) return exited;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) EXPORT_SYMBOL(thread_group_exited);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) __weak void abort(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755) /* if that doesn't kill us, halt */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) panic("Oops failed to kill thread");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) EXPORT_SYMBOL(abort);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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