1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 1991, 1992 Linus Torvalds
9 #include <linux/slab.h>
10 #include <linux/sched/autogroup.h>
11 #include <linux/sched/mm.h>
12 #include <linux/sched/stat.h>
13 #include <linux/sched/task.h>
14 #include <linux/sched/task_stack.h>
15 #include <linux/sched/cputime.h>
16 #include <linux/interrupt.h>
17 #include <linux/module.h>
18 #include <linux/capability.h>
19 #include <linux/completion.h>
20 #include <linux/personality.h>
21 #include <linux/tty.h>
22 #include <linux/iocontext.h>
23 #include <linux/key.h>
24 #include <linux/cpu.h>
25 #include <linux/acct.h>
26 #include <linux/tsacct_kern.h>
27 #include <linux/file.h>
28 #include <linux/fdtable.h>
29 #include <linux/freezer.h>
30 #include <linux/binfmts.h>
31 #include <linux/nsproxy.h>
32 #include <linux/pid_namespace.h>
33 #include <linux/ptrace.h>
34 #include <linux/profile.h>
35 #include <linux/mount.h>
36 #include <linux/proc_fs.h>
37 #include <linux/kthread.h>
38 #include <linux/mempolicy.h>
39 #include <linux/taskstats_kern.h>
40 #include <linux/delayacct.h>
41 #include <linux/cgroup.h>
42 #include <linux/syscalls.h>
43 #include <linux/signal.h>
44 #include <linux/posix-timers.h>
45 #include <linux/cn_proc.h>
46 #include <linux/mutex.h>
47 #include <linux/futex.h>
48 #include <linux/pipe_fs_i.h>
49 #include <linux/audit.h> /* for audit_free() */
50 #include <linux/resource.h>
51 #include <linux/task_io_accounting_ops.h>
52 #include <linux/blkdev.h>
53 #include <linux/task_work.h>
54 #include <linux/fs_struct.h>
55 #include <linux/init_task.h>
56 #include <linux/perf_event.h>
57 #include <trace/events/sched.h>
58 #include <linux/hw_breakpoint.h>
59 #include <linux/oom.h>
60 #include <linux/writeback.h>
61 #include <linux/shm.h>
62 #include <linux/kcov.h>
63 #include <linux/kmsan.h>
64 #include <linux/random.h>
65 #include <linux/rcuwait.h>
66 #include <linux/compat.h>
67 #include <linux/io_uring.h>
68 #include <linux/kprobes.h>
69 #include <linux/rethook.h>
70 #include <linux/sysfs.h>
71 #include <linux/user_events.h>
73 #include <linux/uaccess.h>
74 #include <asm/unistd.h>
75 #include <asm/mmu_context.h>
80 * The default value should be high enough to not crash a system that randomly
81 * crashes its kernel from time to time, but low enough to at least not permit
82 * overflowing 32-bit refcounts or the ldsem writer count.
84 static unsigned int oops_limit = 10000;
87 static struct ctl_table kern_exit_table[] = {
89 .procname = "oops_limit",
91 .maxlen = sizeof(oops_limit),
93 .proc_handler = proc_douintvec,
98 static __init int kernel_exit_sysctls_init(void)
100 register_sysctl_init("kernel", kern_exit_table);
103 late_initcall(kernel_exit_sysctls_init);
106 static atomic_t oops_count = ATOMIC_INIT(0);
109 static ssize_t oops_count_show(struct kobject *kobj, struct kobj_attribute *attr,
112 return sysfs_emit(page, "%d\n", atomic_read(&oops_count));
115 static struct kobj_attribute oops_count_attr = __ATTR_RO(oops_count);
117 static __init int kernel_exit_sysfs_init(void)
119 sysfs_add_file_to_group(kernel_kobj, &oops_count_attr.attr, NULL);
122 late_initcall(kernel_exit_sysfs_init);
125 static void __unhash_process(struct task_struct *p, bool group_dead)
128 detach_pid(p, PIDTYPE_PID);
130 detach_pid(p, PIDTYPE_TGID);
131 detach_pid(p, PIDTYPE_PGID);
132 detach_pid(p, PIDTYPE_SID);
134 list_del_rcu(&p->tasks);
135 list_del_init(&p->sibling);
136 __this_cpu_dec(process_counts);
138 list_del_rcu(&p->thread_node);
142 * This function expects the tasklist_lock write-locked.
144 static void __exit_signal(struct task_struct *tsk)
146 struct signal_struct *sig = tsk->signal;
147 bool group_dead = thread_group_leader(tsk);
148 struct sighand_struct *sighand;
149 struct tty_struct *tty;
152 sighand = rcu_dereference_check(tsk->sighand,
153 lockdep_tasklist_lock_is_held());
154 spin_lock(&sighand->siglock);
156 #ifdef CONFIG_POSIX_TIMERS
157 posix_cpu_timers_exit(tsk);
159 posix_cpu_timers_exit_group(tsk);
167 * If there is any task waiting for the group exit
170 if (sig->notify_count > 0 && !--sig->notify_count)
171 wake_up_process(sig->group_exec_task);
173 if (tsk == sig->curr_target)
174 sig->curr_target = next_thread(tsk);
177 add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
178 sizeof(unsigned long long));
181 * Accumulate here the counters for all threads as they die. We could
182 * skip the group leader because it is the last user of signal_struct,
183 * but we want to avoid the race with thread_group_cputime() which can
184 * see the empty ->thread_head list.
186 task_cputime(tsk, &utime, &stime);
187 write_seqlock(&sig->stats_lock);
190 sig->gtime += task_gtime(tsk);
191 sig->min_flt += tsk->min_flt;
192 sig->maj_flt += tsk->maj_flt;
193 sig->nvcsw += tsk->nvcsw;
194 sig->nivcsw += tsk->nivcsw;
195 sig->inblock += task_io_get_inblock(tsk);
196 sig->oublock += task_io_get_oublock(tsk);
197 task_io_accounting_add(&sig->ioac, &tsk->ioac);
198 sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
200 __unhash_process(tsk, group_dead);
201 write_sequnlock(&sig->stats_lock);
204 * Do this under ->siglock, we can race with another thread
205 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
207 flush_sigqueue(&tsk->pending);
209 spin_unlock(&sighand->siglock);
211 __cleanup_sighand(sighand);
212 clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
214 flush_sigqueue(&sig->shared_pending);
219 static void delayed_put_task_struct(struct rcu_head *rhp)
221 struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
223 kprobe_flush_task(tsk);
224 rethook_flush_task(tsk);
225 perf_event_delayed_put(tsk);
226 trace_sched_process_free(tsk);
227 put_task_struct(tsk);
230 void put_task_struct_rcu_user(struct task_struct *task)
232 if (refcount_dec_and_test(&task->rcu_users))
233 call_rcu(&task->rcu, delayed_put_task_struct);
236 void __weak release_thread(struct task_struct *dead_task)
240 void release_task(struct task_struct *p)
242 struct task_struct *leader;
243 struct pid *thread_pid;
246 /* don't need to get the RCU readlock here - the process is dead and
247 * can't be modifying its own credentials. But shut RCU-lockdep up */
249 dec_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
254 write_lock_irq(&tasklist_lock);
255 ptrace_release_task(p);
256 thread_pid = get_pid(p->thread_pid);
260 * If we are the last non-leader member of the thread
261 * group, and the leader is zombie, then notify the
262 * group leader's parent process. (if it wants notification.)
265 leader = p->group_leader;
266 if (leader != p && thread_group_empty(leader)
267 && leader->exit_state == EXIT_ZOMBIE) {
269 * If we were the last child thread and the leader has
270 * exited already, and the leader's parent ignores SIGCHLD,
271 * then we are the one who should release the leader.
273 zap_leader = do_notify_parent(leader, leader->exit_signal);
275 leader->exit_state = EXIT_DEAD;
278 write_unlock_irq(&tasklist_lock);
279 seccomp_filter_release(p);
280 proc_flush_pid(thread_pid);
283 put_task_struct_rcu_user(p);
286 if (unlikely(zap_leader))
290 int rcuwait_wake_up(struct rcuwait *w)
293 struct task_struct *task;
298 * Order condition vs @task, such that everything prior to the load
299 * of @task is visible. This is the condition as to why the user called
300 * rcuwait_wake() in the first place. Pairs with set_current_state()
301 * barrier (A) in rcuwait_wait_event().
304 * [S] tsk = current [S] cond = true
310 task = rcu_dereference(w->task);
312 ret = wake_up_process(task);
317 EXPORT_SYMBOL_GPL(rcuwait_wake_up);
320 * Determine if a process group is "orphaned", according to the POSIX
321 * definition in 2.2.2.52. Orphaned process groups are not to be affected
322 * by terminal-generated stop signals. Newly orphaned process groups are
323 * to receive a SIGHUP and a SIGCONT.
325 * "I ask you, have you ever known what it is to be an orphan?"
327 static int will_become_orphaned_pgrp(struct pid *pgrp,
328 struct task_struct *ignored_task)
330 struct task_struct *p;
332 do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
333 if ((p == ignored_task) ||
334 (p->exit_state && thread_group_empty(p)) ||
335 is_global_init(p->real_parent))
338 if (task_pgrp(p->real_parent) != pgrp &&
339 task_session(p->real_parent) == task_session(p))
341 } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
346 int is_current_pgrp_orphaned(void)
350 read_lock(&tasklist_lock);
351 retval = will_become_orphaned_pgrp(task_pgrp(current), NULL);
352 read_unlock(&tasklist_lock);
357 static bool has_stopped_jobs(struct pid *pgrp)
359 struct task_struct *p;
361 do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
362 if (p->signal->flags & SIGNAL_STOP_STOPPED)
364 } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
370 * Check to see if any process groups have become orphaned as
371 * a result of our exiting, and if they have any stopped jobs,
372 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
375 kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
377 struct pid *pgrp = task_pgrp(tsk);
378 struct task_struct *ignored_task = tsk;
381 /* exit: our father is in a different pgrp than
382 * we are and we were the only connection outside.
384 parent = tsk->real_parent;
386 /* reparent: our child is in a different pgrp than
387 * we are, and it was the only connection outside.
391 if (task_pgrp(parent) != pgrp &&
392 task_session(parent) == task_session(tsk) &&
393 will_become_orphaned_pgrp(pgrp, ignored_task) &&
394 has_stopped_jobs(pgrp)) {
395 __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
396 __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
400 static void coredump_task_exit(struct task_struct *tsk)
402 struct core_state *core_state;
405 * Serialize with any possible pending coredump.
406 * We must hold siglock around checking core_state
407 * and setting PF_POSTCOREDUMP. The core-inducing thread
408 * will increment ->nr_threads for each thread in the
409 * group without PF_POSTCOREDUMP set.
411 spin_lock_irq(&tsk->sighand->siglock);
412 tsk->flags |= PF_POSTCOREDUMP;
413 core_state = tsk->signal->core_state;
414 spin_unlock_irq(&tsk->sighand->siglock);
416 /* The vhost_worker does not particpate in coredumps */
418 ((tsk->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER)) {
419 struct core_thread self;
422 if (self.task->flags & PF_SIGNALED)
423 self.next = xchg(&core_state->dumper.next, &self);
427 * Implies mb(), the result of xchg() must be visible
428 * to core_state->dumper.
430 if (atomic_dec_and_test(&core_state->nr_threads))
431 complete(&core_state->startup);
434 set_current_state(TASK_UNINTERRUPTIBLE|TASK_FREEZABLE);
435 if (!self.task) /* see coredump_finish() */
439 __set_current_state(TASK_RUNNING);
445 * A task is exiting. If it owned this mm, find a new owner for the mm.
447 void mm_update_next_owner(struct mm_struct *mm)
449 struct task_struct *c, *g, *p = current;
453 * If the exiting or execing task is not the owner, it's
454 * someone else's problem.
459 * The current owner is exiting/execing and there are no other
460 * candidates. Do not leave the mm pointing to a possibly
461 * freed task structure.
463 if (atomic_read(&mm->mm_users) <= 1) {
464 WRITE_ONCE(mm->owner, NULL);
468 read_lock(&tasklist_lock);
470 * Search in the children
472 list_for_each_entry(c, &p->children, sibling) {
474 goto assign_new_owner;
478 * Search in the siblings
480 list_for_each_entry(c, &p->real_parent->children, sibling) {
482 goto assign_new_owner;
486 * Search through everything else, we should not get here often.
488 for_each_process(g) {
489 if (g->flags & PF_KTHREAD)
491 for_each_thread(g, c) {
493 goto assign_new_owner;
498 read_unlock(&tasklist_lock);
500 * We found no owner yet mm_users > 1: this implies that we are
501 * most likely racing with swapoff (try_to_unuse()) or /proc or
502 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
504 WRITE_ONCE(mm->owner, NULL);
511 * The task_lock protects c->mm from changing.
512 * We always want mm->owner->mm == mm
516 * Delay read_unlock() till we have the task_lock()
517 * to ensure that c does not slip away underneath us
519 read_unlock(&tasklist_lock);
525 WRITE_ONCE(mm->owner, c);
526 lru_gen_migrate_mm(mm);
530 #endif /* CONFIG_MEMCG */
533 * Turn us into a lazy TLB process if we
536 static void exit_mm(void)
538 struct mm_struct *mm = current->mm;
540 exit_mm_release(current, mm);
545 BUG_ON(mm != current->active_mm);
546 /* more a memory barrier than a real lock */
549 * When a thread stops operating on an address space, the loop
550 * in membarrier_private_expedited() may not observe that
551 * tsk->mm, and the loop in membarrier_global_expedited() may
552 * not observe a MEMBARRIER_STATE_GLOBAL_EXPEDITED
553 * rq->membarrier_state, so those would not issue an IPI.
554 * Membarrier requires a memory barrier after accessing
555 * user-space memory, before clearing tsk->mm or the
556 * rq->membarrier_state.
558 smp_mb__after_spinlock();
561 membarrier_update_current_mm(NULL);
562 enter_lazy_tlb(mm, current);
564 task_unlock(current);
565 mmap_read_unlock(mm);
566 mm_update_next_owner(mm);
568 if (test_thread_flag(TIF_MEMDIE))
572 static struct task_struct *find_alive_thread(struct task_struct *p)
574 struct task_struct *t;
576 for_each_thread(p, t) {
577 if (!(t->flags & PF_EXITING))
583 static struct task_struct *find_child_reaper(struct task_struct *father,
584 struct list_head *dead)
585 __releases(&tasklist_lock)
586 __acquires(&tasklist_lock)
588 struct pid_namespace *pid_ns = task_active_pid_ns(father);
589 struct task_struct *reaper = pid_ns->child_reaper;
590 struct task_struct *p, *n;
592 if (likely(reaper != father))
595 reaper = find_alive_thread(father);
597 pid_ns->child_reaper = reaper;
601 write_unlock_irq(&tasklist_lock);
603 list_for_each_entry_safe(p, n, dead, ptrace_entry) {
604 list_del_init(&p->ptrace_entry);
608 zap_pid_ns_processes(pid_ns);
609 write_lock_irq(&tasklist_lock);
615 * When we die, we re-parent all our children, and try to:
616 * 1. give them to another thread in our thread group, if such a member exists
617 * 2. give it to the first ancestor process which prctl'd itself as a
618 * child_subreaper for its children (like a service manager)
619 * 3. give it to the init process (PID 1) in our pid namespace
621 static struct task_struct *find_new_reaper(struct task_struct *father,
622 struct task_struct *child_reaper)
624 struct task_struct *thread, *reaper;
626 thread = find_alive_thread(father);
630 if (father->signal->has_child_subreaper) {
631 unsigned int ns_level = task_pid(father)->level;
633 * Find the first ->is_child_subreaper ancestor in our pid_ns.
634 * We can't check reaper != child_reaper to ensure we do not
635 * cross the namespaces, the exiting parent could be injected
636 * by setns() + fork().
637 * We check pid->level, this is slightly more efficient than
638 * task_active_pid_ns(reaper) != task_active_pid_ns(father).
640 for (reaper = father->real_parent;
641 task_pid(reaper)->level == ns_level;
642 reaper = reaper->real_parent) {
643 if (reaper == &init_task)
645 if (!reaper->signal->is_child_subreaper)
647 thread = find_alive_thread(reaper);
657 * Any that need to be release_task'd are put on the @dead list.
659 static void reparent_leader(struct task_struct *father, struct task_struct *p,
660 struct list_head *dead)
662 if (unlikely(p->exit_state == EXIT_DEAD))
665 /* We don't want people slaying init. */
666 p->exit_signal = SIGCHLD;
668 /* If it has exited notify the new parent about this child's death. */
670 p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
671 if (do_notify_parent(p, p->exit_signal)) {
672 p->exit_state = EXIT_DEAD;
673 list_add(&p->ptrace_entry, dead);
677 kill_orphaned_pgrp(p, father);
681 * This does two things:
683 * A. Make init inherit all the child processes
684 * B. Check to see if any process groups have become orphaned
685 * as a result of our exiting, and if they have any stopped
686 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
688 static void forget_original_parent(struct task_struct *father,
689 struct list_head *dead)
691 struct task_struct *p, *t, *reaper;
693 if (unlikely(!list_empty(&father->ptraced)))
694 exit_ptrace(father, dead);
696 /* Can drop and reacquire tasklist_lock */
697 reaper = find_child_reaper(father, dead);
698 if (list_empty(&father->children))
701 reaper = find_new_reaper(father, reaper);
702 list_for_each_entry(p, &father->children, sibling) {
703 for_each_thread(p, t) {
704 RCU_INIT_POINTER(t->real_parent, reaper);
705 BUG_ON((!t->ptrace) != (rcu_access_pointer(t->parent) == father));
706 if (likely(!t->ptrace))
707 t->parent = t->real_parent;
708 if (t->pdeath_signal)
709 group_send_sig_info(t->pdeath_signal,
714 * If this is a threaded reparent there is no need to
715 * notify anyone anything has happened.
717 if (!same_thread_group(reaper, father))
718 reparent_leader(father, p, dead);
720 list_splice_tail_init(&father->children, &reaper->children);
724 * Send signals to all our closest relatives so that they know
725 * to properly mourn us..
727 static void exit_notify(struct task_struct *tsk, int group_dead)
730 struct task_struct *p, *n;
733 write_lock_irq(&tasklist_lock);
734 forget_original_parent(tsk, &dead);
737 kill_orphaned_pgrp(tsk->group_leader, NULL);
739 tsk->exit_state = EXIT_ZOMBIE;
740 if (unlikely(tsk->ptrace)) {
741 int sig = thread_group_leader(tsk) &&
742 thread_group_empty(tsk) &&
743 !ptrace_reparented(tsk) ?
744 tsk->exit_signal : SIGCHLD;
745 autoreap = do_notify_parent(tsk, sig);
746 } else if (thread_group_leader(tsk)) {
747 autoreap = thread_group_empty(tsk) &&
748 do_notify_parent(tsk, tsk->exit_signal);
754 tsk->exit_state = EXIT_DEAD;
755 list_add(&tsk->ptrace_entry, &dead);
758 /* mt-exec, de_thread() is waiting for group leader */
759 if (unlikely(tsk->signal->notify_count < 0))
760 wake_up_process(tsk->signal->group_exec_task);
761 write_unlock_irq(&tasklist_lock);
763 list_for_each_entry_safe(p, n, &dead, ptrace_entry) {
764 list_del_init(&p->ptrace_entry);
769 #ifdef CONFIG_DEBUG_STACK_USAGE
770 static void check_stack_usage(void)
772 static DEFINE_SPINLOCK(low_water_lock);
773 static int lowest_to_date = THREAD_SIZE;
776 free = stack_not_used(current);
778 if (free >= lowest_to_date)
781 spin_lock(&low_water_lock);
782 if (free < lowest_to_date) {
783 pr_info("%s (%d) used greatest stack depth: %lu bytes left\n",
784 current->comm, task_pid_nr(current), free);
785 lowest_to_date = free;
787 spin_unlock(&low_water_lock);
790 static inline void check_stack_usage(void) {}
793 static void synchronize_group_exit(struct task_struct *tsk, long code)
795 struct sighand_struct *sighand = tsk->sighand;
796 struct signal_struct *signal = tsk->signal;
798 spin_lock_irq(&sighand->siglock);
799 signal->quick_threads--;
800 if ((signal->quick_threads == 0) &&
801 !(signal->flags & SIGNAL_GROUP_EXIT)) {
802 signal->flags = SIGNAL_GROUP_EXIT;
803 signal->group_exit_code = code;
804 signal->group_stop_count = 0;
806 spin_unlock_irq(&sighand->siglock);
809 void __noreturn do_exit(long code)
811 struct task_struct *tsk = current;
814 WARN_ON(irqs_disabled());
816 synchronize_group_exit(tsk, code);
821 kmsan_task_exit(tsk);
823 coredump_task_exit(tsk);
824 ptrace_event(PTRACE_EVENT_EXIT, code);
825 user_events_exit(tsk);
827 io_uring_files_cancel();
828 exit_signals(tsk); /* sets PF_EXITING */
830 acct_update_integrals(tsk);
831 group_dead = atomic_dec_and_test(&tsk->signal->live);
834 * If the last thread of global init has exited, panic
835 * immediately to get a useable coredump.
837 if (unlikely(is_global_init(tsk)))
838 panic("Attempted to kill init! exitcode=0x%08x\n",
839 tsk->signal->group_exit_code ?: (int)code);
841 #ifdef CONFIG_POSIX_TIMERS
842 hrtimer_cancel(&tsk->signal->real_timer);
846 setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
848 acct_collect(code, group_dead);
853 tsk->exit_code = code;
854 taskstats_exit(tsk, group_dead);
860 trace_sched_process_exit(tsk);
867 disassociate_ctty(1);
868 exit_task_namespaces(tsk);
873 * Flush inherited counters to the parent - before the parent
874 * gets woken up by child-exit notifications.
876 * because of cgroup mode, must be called before cgroup_exit()
878 perf_event_exit_task(tsk);
880 sched_autogroup_exit_task(tsk);
884 * FIXME: do that only when needed, using sched_exit tracepoint
886 flush_ptrace_hw_breakpoint(tsk);
888 exit_tasks_rcu_start();
889 exit_notify(tsk, group_dead);
890 proc_exit_connector(tsk);
891 mpol_put_task_policy(tsk);
893 if (unlikely(current->pi_state_cache))
894 kfree(current->pi_state_cache);
897 * Make sure we are holding no locks:
899 debug_check_no_locks_held();
902 exit_io_context(tsk);
904 if (tsk->splice_pipe)
905 free_pipe_info(tsk->splice_pipe);
907 if (tsk->task_frag.page)
908 put_page(tsk->task_frag.page);
910 exit_task_stack_account(tsk);
915 __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
917 exit_tasks_rcu_finish();
919 lockdep_free_task(tsk);
923 void __noreturn make_task_dead(int signr)
926 * Take the task off the cpu after something catastrophic has
929 * We can get here from a kernel oops, sometimes with preemption off.
930 * Start by checking for critical errors.
931 * Then fix up important state like USER_DS and preemption.
932 * Then do everything else.
934 struct task_struct *tsk = current;
937 if (unlikely(in_interrupt()))
938 panic("Aiee, killing interrupt handler!");
939 if (unlikely(!tsk->pid))
940 panic("Attempted to kill the idle task!");
942 if (unlikely(irqs_disabled())) {
943 pr_info("note: %s[%d] exited with irqs disabled\n",
944 current->comm, task_pid_nr(current));
947 if (unlikely(in_atomic())) {
948 pr_info("note: %s[%d] exited with preempt_count %d\n",
949 current->comm, task_pid_nr(current),
951 preempt_count_set(PREEMPT_ENABLED);
955 * Every time the system oopses, if the oops happens while a reference
956 * to an object was held, the reference leaks.
957 * If the oops doesn't also leak memory, repeated oopsing can cause
958 * reference counters to wrap around (if they're not using refcount_t).
959 * This means that repeated oopsing can make unexploitable-looking bugs
960 * exploitable through repeated oopsing.
961 * To make sure this can't happen, place an upper bound on how often the
962 * kernel may oops without panic().
964 limit = READ_ONCE(oops_limit);
965 if (atomic_inc_return(&oops_count) >= limit && limit)
966 panic("Oopsed too often (kernel.oops_limit is %d)", limit);
969 * We're taking recursive faults here in make_task_dead. Safest is to just
970 * leave this task alone and wait for reboot.
972 if (unlikely(tsk->flags & PF_EXITING)) {
973 pr_alert("Fixing recursive fault but reboot is needed!\n");
974 futex_exit_recursive(tsk);
975 tsk->exit_state = EXIT_DEAD;
976 refcount_inc(&tsk->rcu_users);
983 SYSCALL_DEFINE1(exit, int, error_code)
985 do_exit((error_code&0xff)<<8);
989 * Take down every thread in the group. This is called by fatal signals
990 * as well as by sys_exit_group (below).
993 do_group_exit(int exit_code)
995 struct signal_struct *sig = current->signal;
997 if (sig->flags & SIGNAL_GROUP_EXIT)
998 exit_code = sig->group_exit_code;
999 else if (sig->group_exec_task)
1002 struct sighand_struct *const sighand = current->sighand;
1004 spin_lock_irq(&sighand->siglock);
1005 if (sig->flags & SIGNAL_GROUP_EXIT)
1006 /* Another thread got here before we took the lock. */
1007 exit_code = sig->group_exit_code;
1008 else if (sig->group_exec_task)
1011 sig->group_exit_code = exit_code;
1012 sig->flags = SIGNAL_GROUP_EXIT;
1013 zap_other_threads(current);
1015 spin_unlock_irq(&sighand->siglock);
1023 * this kills every thread in the thread group. Note that any externally
1024 * wait4()-ing process will get the correct exit code - even if this
1025 * thread is not the thread group leader.
1027 SYSCALL_DEFINE1(exit_group, int, error_code)
1029 do_group_exit((error_code & 0xff) << 8);
1034 static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
1036 return wo->wo_type == PIDTYPE_MAX ||
1037 task_pid_type(p, wo->wo_type) == wo->wo_pid;
1041 eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
1043 if (!eligible_pid(wo, p))
1047 * Wait for all children (clone and not) if __WALL is set or
1048 * if it is traced by us.
1050 if (ptrace || (wo->wo_flags & __WALL))
1054 * Otherwise, wait for clone children *only* if __WCLONE is set;
1055 * otherwise, wait for non-clone children *only*.
1057 * Note: a "clone" child here is one that reports to its parent
1058 * using a signal other than SIGCHLD, or a non-leader thread which
1059 * we can only see if it is traced by us.
1061 if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
1068 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1069 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1070 * the lock and this task is uninteresting. If we return nonzero, we have
1071 * released the lock and the system call should return.
1073 static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
1076 pid_t pid = task_pid_vnr(p);
1077 uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
1078 struct waitid_info *infop;
1080 if (!likely(wo->wo_flags & WEXITED))
1083 if (unlikely(wo->wo_flags & WNOWAIT)) {
1084 status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1085 ? p->signal->group_exit_code : p->exit_code;
1087 read_unlock(&tasklist_lock);
1088 sched_annotate_sleep();
1090 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1095 * Move the task's state to DEAD/TRACE, only one thread can do this.
1097 state = (ptrace_reparented(p) && thread_group_leader(p)) ?
1098 EXIT_TRACE : EXIT_DEAD;
1099 if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)
1102 * We own this thread, nobody else can reap it.
1104 read_unlock(&tasklist_lock);
1105 sched_annotate_sleep();
1108 * Check thread_group_leader() to exclude the traced sub-threads.
1110 if (state == EXIT_DEAD && thread_group_leader(p)) {
1111 struct signal_struct *sig = p->signal;
1112 struct signal_struct *psig = current->signal;
1113 unsigned long maxrss;
1114 u64 tgutime, tgstime;
1117 * The resource counters for the group leader are in its
1118 * own task_struct. Those for dead threads in the group
1119 * are in its signal_struct, as are those for the child
1120 * processes it has previously reaped. All these
1121 * accumulate in the parent's signal_struct c* fields.
1123 * We don't bother to take a lock here to protect these
1124 * p->signal fields because the whole thread group is dead
1125 * and nobody can change them.
1127 * psig->stats_lock also protects us from our sub-threads
1128 * which can reap other children at the same time. Until
1129 * we change k_getrusage()-like users to rely on this lock
1130 * we have to take ->siglock as well.
1132 * We use thread_group_cputime_adjusted() to get times for
1133 * the thread group, which consolidates times for all threads
1134 * in the group including the group leader.
1136 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1137 spin_lock_irq(¤t->sighand->siglock);
1138 write_seqlock(&psig->stats_lock);
1139 psig->cutime += tgutime + sig->cutime;
1140 psig->cstime += tgstime + sig->cstime;
1141 psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime;
1143 p->min_flt + sig->min_flt + sig->cmin_flt;
1145 p->maj_flt + sig->maj_flt + sig->cmaj_flt;
1147 p->nvcsw + sig->nvcsw + sig->cnvcsw;
1149 p->nivcsw + sig->nivcsw + sig->cnivcsw;
1151 task_io_get_inblock(p) +
1152 sig->inblock + sig->cinblock;
1154 task_io_get_oublock(p) +
1155 sig->oublock + sig->coublock;
1156 maxrss = max(sig->maxrss, sig->cmaxrss);
1157 if (psig->cmaxrss < maxrss)
1158 psig->cmaxrss = maxrss;
1159 task_io_accounting_add(&psig->ioac, &p->ioac);
1160 task_io_accounting_add(&psig->ioac, &sig->ioac);
1161 write_sequnlock(&psig->stats_lock);
1162 spin_unlock_irq(¤t->sighand->siglock);
1166 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1167 status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1168 ? p->signal->group_exit_code : p->exit_code;
1169 wo->wo_stat = status;
1171 if (state == EXIT_TRACE) {
1172 write_lock_irq(&tasklist_lock);
1173 /* We dropped tasklist, ptracer could die and untrace */
1176 /* If parent wants a zombie, don't release it now */
1177 state = EXIT_ZOMBIE;
1178 if (do_notify_parent(p, p->exit_signal))
1180 p->exit_state = state;
1181 write_unlock_irq(&tasklist_lock);
1183 if (state == EXIT_DEAD)
1187 infop = wo->wo_info;
1189 if ((status & 0x7f) == 0) {
1190 infop->cause = CLD_EXITED;
1191 infop->status = status >> 8;
1193 infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
1194 infop->status = status & 0x7f;
1203 static int *task_stopped_code(struct task_struct *p, bool ptrace)
1206 if (task_is_traced(p) && !(p->jobctl & JOBCTL_LISTENING))
1207 return &p->exit_code;
1209 if (p->signal->flags & SIGNAL_STOP_STOPPED)
1210 return &p->signal->group_exit_code;
1216 * wait_task_stopped - Wait for %TASK_STOPPED or %TASK_TRACED
1218 * @ptrace: is the wait for ptrace
1219 * @p: task to wait for
1221 * Handle sys_wait4() work for %p in state %TASK_STOPPED or %TASK_TRACED.
1224 * read_lock(&tasklist_lock), which is released if return value is
1225 * non-zero. Also, grabs and releases @p->sighand->siglock.
1228 * 0 if wait condition didn't exist and search for other wait conditions
1229 * should continue. Non-zero return, -errno on failure and @p's pid on
1230 * success, implies that tasklist_lock is released and wait condition
1231 * search should terminate.
1233 static int wait_task_stopped(struct wait_opts *wo,
1234 int ptrace, struct task_struct *p)
1236 struct waitid_info *infop;
1237 int exit_code, *p_code, why;
1238 uid_t uid = 0; /* unneeded, required by compiler */
1242 * Traditionally we see ptrace'd stopped tasks regardless of options.
1244 if (!ptrace && !(wo->wo_flags & WUNTRACED))
1247 if (!task_stopped_code(p, ptrace))
1251 spin_lock_irq(&p->sighand->siglock);
1253 p_code = task_stopped_code(p, ptrace);
1254 if (unlikely(!p_code))
1257 exit_code = *p_code;
1261 if (!unlikely(wo->wo_flags & WNOWAIT))
1264 uid = from_kuid_munged(current_user_ns(), task_uid(p));
1266 spin_unlock_irq(&p->sighand->siglock);
1271 * Now we are pretty sure this task is interesting.
1272 * Make sure it doesn't get reaped out from under us while we
1273 * give up the lock and then examine it below. We don't want to
1274 * keep holding onto the tasklist_lock while we call getrusage and
1275 * possibly take page faults for user memory.
1278 pid = task_pid_vnr(p);
1279 why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
1280 read_unlock(&tasklist_lock);
1281 sched_annotate_sleep();
1283 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1286 if (likely(!(wo->wo_flags & WNOWAIT)))
1287 wo->wo_stat = (exit_code << 8) | 0x7f;
1289 infop = wo->wo_info;
1292 infop->status = exit_code;
1300 * Handle do_wait work for one task in a live, non-stopped state.
1301 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1302 * the lock and this task is uninteresting. If we return nonzero, we have
1303 * released the lock and the system call should return.
1305 static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
1307 struct waitid_info *infop;
1311 if (!unlikely(wo->wo_flags & WCONTINUED))
1314 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
1317 spin_lock_irq(&p->sighand->siglock);
1318 /* Re-check with the lock held. */
1319 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
1320 spin_unlock_irq(&p->sighand->siglock);
1323 if (!unlikely(wo->wo_flags & WNOWAIT))
1324 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
1325 uid = from_kuid_munged(current_user_ns(), task_uid(p));
1326 spin_unlock_irq(&p->sighand->siglock);
1328 pid = task_pid_vnr(p);
1330 read_unlock(&tasklist_lock);
1331 sched_annotate_sleep();
1333 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1336 infop = wo->wo_info;
1338 wo->wo_stat = 0xffff;
1340 infop->cause = CLD_CONTINUED;
1343 infop->status = SIGCONT;
1349 * Consider @p for a wait by @parent.
1351 * -ECHILD should be in ->notask_error before the first call.
1352 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1353 * Returns zero if the search for a child should continue;
1354 * then ->notask_error is 0 if @p is an eligible child,
1357 static int wait_consider_task(struct wait_opts *wo, int ptrace,
1358 struct task_struct *p)
1361 * We can race with wait_task_zombie() from another thread.
1362 * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
1363 * can't confuse the checks below.
1365 int exit_state = READ_ONCE(p->exit_state);
1368 if (unlikely(exit_state == EXIT_DEAD))
1371 ret = eligible_child(wo, ptrace, p);
1375 if (unlikely(exit_state == EXIT_TRACE)) {
1377 * ptrace == 0 means we are the natural parent. In this case
1378 * we should clear notask_error, debugger will notify us.
1380 if (likely(!ptrace))
1381 wo->notask_error = 0;
1385 if (likely(!ptrace) && unlikely(p->ptrace)) {
1387 * If it is traced by its real parent's group, just pretend
1388 * the caller is ptrace_do_wait() and reap this child if it
1391 * This also hides group stop state from real parent; otherwise
1392 * a single stop can be reported twice as group and ptrace stop.
1393 * If a ptracer wants to distinguish these two events for its
1394 * own children it should create a separate process which takes
1395 * the role of real parent.
1397 if (!ptrace_reparented(p))
1402 if (exit_state == EXIT_ZOMBIE) {
1403 /* we don't reap group leaders with subthreads */
1404 if (!delay_group_leader(p)) {
1406 * A zombie ptracee is only visible to its ptracer.
1407 * Notification and reaping will be cascaded to the
1408 * real parent when the ptracer detaches.
1410 if (unlikely(ptrace) || likely(!p->ptrace))
1411 return wait_task_zombie(wo, p);
1415 * Allow access to stopped/continued state via zombie by
1416 * falling through. Clearing of notask_error is complex.
1420 * If WEXITED is set, notask_error should naturally be
1421 * cleared. If not, subset of WSTOPPED|WCONTINUED is set,
1422 * so, if there are live subthreads, there are events to
1423 * wait for. If all subthreads are dead, it's still safe
1424 * to clear - this function will be called again in finite
1425 * amount time once all the subthreads are released and
1426 * will then return without clearing.
1430 * Stopped state is per-task and thus can't change once the
1431 * target task dies. Only continued and exited can happen.
1432 * Clear notask_error if WCONTINUED | WEXITED.
1434 if (likely(!ptrace) || (wo->wo_flags & (WCONTINUED | WEXITED)))
1435 wo->notask_error = 0;
1438 * @p is alive and it's gonna stop, continue or exit, so
1439 * there always is something to wait for.
1441 wo->notask_error = 0;
1445 * Wait for stopped. Depending on @ptrace, different stopped state
1446 * is used and the two don't interact with each other.
1448 ret = wait_task_stopped(wo, ptrace, p);
1453 * Wait for continued. There's only one continued state and the
1454 * ptracer can consume it which can confuse the real parent. Don't
1455 * use WCONTINUED from ptracer. You don't need or want it.
1457 return wait_task_continued(wo, p);
1461 * Do the work of do_wait() for one thread in the group, @tsk.
1463 * -ECHILD should be in ->notask_error before the first call.
1464 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1465 * Returns zero if the search for a child should continue; then
1466 * ->notask_error is 0 if there were any eligible children,
1469 static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
1471 struct task_struct *p;
1473 list_for_each_entry(p, &tsk->children, sibling) {
1474 int ret = wait_consider_task(wo, 0, p);
1483 static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
1485 struct task_struct *p;
1487 list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
1488 int ret = wait_consider_task(wo, 1, p);
1497 bool pid_child_should_wake(struct wait_opts *wo, struct task_struct *p)
1499 if (!eligible_pid(wo, p))
1502 if ((wo->wo_flags & __WNOTHREAD) && wo->child_wait.private != p->parent)
1508 static int child_wait_callback(wait_queue_entry_t *wait, unsigned mode,
1509 int sync, void *key)
1511 struct wait_opts *wo = container_of(wait, struct wait_opts,
1513 struct task_struct *p = key;
1515 if (pid_child_should_wake(wo, p))
1516 return default_wake_function(wait, mode, sync, key);
1521 void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
1523 __wake_up_sync_key(&parent->signal->wait_chldexit,
1524 TASK_INTERRUPTIBLE, p);
1527 static bool is_effectively_child(struct wait_opts *wo, bool ptrace,
1528 struct task_struct *target)
1530 struct task_struct *parent =
1531 !ptrace ? target->real_parent : target->parent;
1533 return current == parent || (!(wo->wo_flags & __WNOTHREAD) &&
1534 same_thread_group(current, parent));
1538 * Optimization for waiting on PIDTYPE_PID. No need to iterate through child
1539 * and tracee lists to find the target task.
1541 static int do_wait_pid(struct wait_opts *wo)
1544 struct task_struct *target;
1548 target = pid_task(wo->wo_pid, PIDTYPE_TGID);
1549 if (target && is_effectively_child(wo, ptrace, target)) {
1550 retval = wait_consider_task(wo, ptrace, target);
1556 target = pid_task(wo->wo_pid, PIDTYPE_PID);
1557 if (target && target->ptrace &&
1558 is_effectively_child(wo, ptrace, target)) {
1559 retval = wait_consider_task(wo, ptrace, target);
1567 long __do_wait(struct wait_opts *wo)
1572 * If there is nothing that can match our criteria, just get out.
1573 * We will clear ->notask_error to zero if we see any child that
1574 * might later match our criteria, even if we are not able to reap
1577 wo->notask_error = -ECHILD;
1578 if ((wo->wo_type < PIDTYPE_MAX) &&
1579 (!wo->wo_pid || !pid_has_task(wo->wo_pid, wo->wo_type)))
1582 read_lock(&tasklist_lock);
1584 if (wo->wo_type == PIDTYPE_PID) {
1585 retval = do_wait_pid(wo);
1589 struct task_struct *tsk = current;
1592 retval = do_wait_thread(wo, tsk);
1596 retval = ptrace_do_wait(wo, tsk);
1600 if (wo->wo_flags & __WNOTHREAD)
1602 } while_each_thread(current, tsk);
1604 read_unlock(&tasklist_lock);
1607 retval = wo->notask_error;
1608 if (!retval && !(wo->wo_flags & WNOHANG))
1609 return -ERESTARTSYS;
1614 static long do_wait(struct wait_opts *wo)
1618 trace_sched_process_wait(wo->wo_pid);
1620 init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
1621 wo->child_wait.private = current;
1622 add_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
1625 set_current_state(TASK_INTERRUPTIBLE);
1626 retval = __do_wait(wo);
1627 if (retval != -ERESTARTSYS)
1629 if (signal_pending(current))
1634 __set_current_state(TASK_RUNNING);
1635 remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
1639 int kernel_waitid_prepare(struct wait_opts *wo, int which, pid_t upid,
1640 struct waitid_info *infop, int options,
1643 unsigned int f_flags = 0;
1644 struct pid *pid = NULL;
1647 if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
1648 __WNOTHREAD|__WCLONE|__WALL))
1650 if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
1662 pid = find_get_pid(upid);
1665 type = PIDTYPE_PGID;
1670 pid = find_get_pid(upid);
1672 pid = get_task_pid(current, PIDTYPE_PGID);
1679 pid = pidfd_get_pid(upid, &f_flags);
1681 return PTR_ERR(pid);
1690 wo->wo_flags = options;
1691 wo->wo_info = infop;
1693 if (f_flags & O_NONBLOCK)
1694 wo->wo_flags |= WNOHANG;
1699 static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
1700 int options, struct rusage *ru)
1702 struct wait_opts wo;
1705 ret = kernel_waitid_prepare(&wo, which, upid, infop, options, ru);
1710 if (!ret && !(options & WNOHANG) && (wo.wo_flags & WNOHANG))
1717 SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
1718 infop, int, options, struct rusage __user *, ru)
1721 struct waitid_info info = {.status = 0};
1722 long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
1728 if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
1734 if (!user_write_access_begin(infop, sizeof(*infop)))
1737 unsafe_put_user(signo, &infop->si_signo, Efault);
1738 unsafe_put_user(0, &infop->si_errno, Efault);
1739 unsafe_put_user(info.cause, &infop->si_code, Efault);
1740 unsafe_put_user(info.pid, &infop->si_pid, Efault);
1741 unsafe_put_user(info.uid, &infop->si_uid, Efault);
1742 unsafe_put_user(info.status, &infop->si_status, Efault);
1743 user_write_access_end();
1746 user_write_access_end();
1750 long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
1753 struct wait_opts wo;
1754 struct pid *pid = NULL;
1758 if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
1759 __WNOTHREAD|__WCLONE|__WALL))
1762 /* -INT_MIN is not defined */
1763 if (upid == INT_MIN)
1768 else if (upid < 0) {
1769 type = PIDTYPE_PGID;
1770 pid = find_get_pid(-upid);
1771 } else if (upid == 0) {
1772 type = PIDTYPE_PGID;
1773 pid = get_task_pid(current, PIDTYPE_PGID);
1774 } else /* upid > 0 */ {
1776 pid = find_get_pid(upid);
1781 wo.wo_flags = options | WEXITED;
1787 if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
1793 int kernel_wait(pid_t pid, int *stat)
1795 struct wait_opts wo = {
1796 .wo_type = PIDTYPE_PID,
1797 .wo_pid = find_get_pid(pid),
1798 .wo_flags = WEXITED,
1803 if (ret > 0 && wo.wo_stat)
1809 SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
1810 int, options, struct rusage __user *, ru)
1813 long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);
1816 if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
1822 #ifdef __ARCH_WANT_SYS_WAITPID
1825 * sys_waitpid() remains for compatibility. waitpid() should be
1826 * implemented by calling sys_wait4() from libc.a.
1828 SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
1830 return kernel_wait4(pid, stat_addr, options, NULL);
1835 #ifdef CONFIG_COMPAT
1836 COMPAT_SYSCALL_DEFINE4(wait4,
1838 compat_uint_t __user *, stat_addr,
1840 struct compat_rusage __user *, ru)
1843 long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);
1845 if (ru && put_compat_rusage(&r, ru))
1851 COMPAT_SYSCALL_DEFINE5(waitid,
1852 int, which, compat_pid_t, pid,
1853 struct compat_siginfo __user *, infop, int, options,
1854 struct compat_rusage __user *, uru)
1857 struct waitid_info info = {.status = 0};
1858 long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
1864 /* kernel_waitid() overwrites everything in ru */
1865 if (COMPAT_USE_64BIT_TIME)
1866 err = copy_to_user(uru, &ru, sizeof(ru));
1868 err = put_compat_rusage(&ru, uru);
1877 if (!user_write_access_begin(infop, sizeof(*infop)))
1880 unsafe_put_user(signo, &infop->si_signo, Efault);
1881 unsafe_put_user(0, &infop->si_errno, Efault);
1882 unsafe_put_user(info.cause, &infop->si_code, Efault);
1883 unsafe_put_user(info.pid, &infop->si_pid, Efault);
1884 unsafe_put_user(info.uid, &infop->si_uid, Efault);
1885 unsafe_put_user(info.status, &infop->si_status, Efault);
1886 user_write_access_end();
1889 user_write_access_end();
1895 * thread_group_exited - check that a thread group has exited
1896 * @pid: tgid of thread group to be checked.
1898 * Test if the thread group represented by tgid has exited (all
1899 * threads are zombies, dead or completely gone).
1901 * Return: true if the thread group has exited. false otherwise.
1903 bool thread_group_exited(struct pid *pid)
1905 struct task_struct *task;
1909 task = pid_task(pid, PIDTYPE_PID);
1911 (READ_ONCE(task->exit_state) && thread_group_empty(task));
1916 EXPORT_SYMBOL(thread_group_exited);
1919 * This needs to be __function_aligned as GCC implicitly makes any
1920 * implementation of abort() cold and drops alignment specified by
1921 * -falign-functions=N.
1923 * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c11
1925 __weak __function_aligned void abort(void)
1929 /* if that doesn't kill us, halt */
1930 panic("Oops failed to kill thread");
1932 EXPORT_SYMBOL(abort);