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>
72 #include <linux/uaccess.h>
74 #include <uapi/linux/wait.h>
76 #include <asm/unistd.h>
77 #include <asm/mmu_context.h>
82 * The default value should be high enough to not crash a system that randomly
83 * crashes its kernel from time to time, but low enough to at least not permit
84 * overflowing 32-bit refcounts or the ldsem writer count.
86 static unsigned int oops_limit = 10000;
89 static struct ctl_table kern_exit_table[] = {
91 .procname = "oops_limit",
93 .maxlen = sizeof(oops_limit),
95 .proc_handler = proc_douintvec,
99 static __init int kernel_exit_sysctls_init(void)
101 register_sysctl_init("kernel", kern_exit_table);
104 late_initcall(kernel_exit_sysctls_init);
107 static atomic_t oops_count = ATOMIC_INIT(0);
110 static ssize_t oops_count_show(struct kobject *kobj, struct kobj_attribute *attr,
113 return sysfs_emit(page, "%d\n", atomic_read(&oops_count));
116 static struct kobj_attribute oops_count_attr = __ATTR_RO(oops_count);
118 static __init int kernel_exit_sysfs_init(void)
120 sysfs_add_file_to_group(kernel_kobj, &oops_count_attr.attr, NULL);
123 late_initcall(kernel_exit_sysfs_init);
126 static void __unhash_process(struct task_struct *p, bool group_dead)
129 detach_pid(p, PIDTYPE_PID);
131 detach_pid(p, PIDTYPE_TGID);
132 detach_pid(p, PIDTYPE_PGID);
133 detach_pid(p, PIDTYPE_SID);
135 list_del_rcu(&p->tasks);
136 list_del_init(&p->sibling);
137 __this_cpu_dec(process_counts);
139 list_del_rcu(&p->thread_node);
143 * This function expects the tasklist_lock write-locked.
145 static void __exit_signal(struct task_struct *tsk)
147 struct signal_struct *sig = tsk->signal;
148 bool group_dead = thread_group_leader(tsk);
149 struct sighand_struct *sighand;
150 struct tty_struct *tty;
153 sighand = rcu_dereference_check(tsk->sighand,
154 lockdep_tasklist_lock_is_held());
155 spin_lock(&sighand->siglock);
157 #ifdef CONFIG_POSIX_TIMERS
158 posix_cpu_timers_exit(tsk);
160 posix_cpu_timers_exit_group(tsk);
168 * If there is any task waiting for the group exit
171 if (sig->notify_count > 0 && !--sig->notify_count)
172 wake_up_process(sig->group_exec_task);
174 if (tsk == sig->curr_target)
175 sig->curr_target = next_thread(tsk);
178 add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
179 sizeof(unsigned long long));
182 * Accumulate here the counters for all threads as they die. We could
183 * skip the group leader because it is the last user of signal_struct,
184 * but we want to avoid the race with thread_group_cputime() which can
185 * see the empty ->thread_head list.
187 task_cputime(tsk, &utime, &stime);
188 write_seqlock(&sig->stats_lock);
191 sig->gtime += task_gtime(tsk);
192 sig->min_flt += tsk->min_flt;
193 sig->maj_flt += tsk->maj_flt;
194 sig->nvcsw += tsk->nvcsw;
195 sig->nivcsw += tsk->nivcsw;
196 sig->inblock += task_io_get_inblock(tsk);
197 sig->oublock += task_io_get_oublock(tsk);
198 task_io_accounting_add(&sig->ioac, &tsk->ioac);
199 sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
201 __unhash_process(tsk, group_dead);
202 write_sequnlock(&sig->stats_lock);
205 * Do this under ->siglock, we can race with another thread
206 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
208 flush_sigqueue(&tsk->pending);
210 spin_unlock(&sighand->siglock);
212 __cleanup_sighand(sighand);
213 clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
215 flush_sigqueue(&sig->shared_pending);
220 static void delayed_put_task_struct(struct rcu_head *rhp)
222 struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
224 kprobe_flush_task(tsk);
225 rethook_flush_task(tsk);
226 perf_event_delayed_put(tsk);
227 trace_sched_process_free(tsk);
228 put_task_struct(tsk);
231 void put_task_struct_rcu_user(struct task_struct *task)
233 if (refcount_dec_and_test(&task->rcu_users))
234 call_rcu(&task->rcu, delayed_put_task_struct);
237 void __weak release_thread(struct task_struct *dead_task)
241 void release_task(struct task_struct *p)
243 struct task_struct *leader;
244 struct pid *thread_pid;
247 /* don't need to get the RCU readlock here - the process is dead and
248 * can't be modifying its own credentials. But shut RCU-lockdep up */
250 dec_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
255 write_lock_irq(&tasklist_lock);
256 ptrace_release_task(p);
257 thread_pid = get_pid(p->thread_pid);
261 * If we are the last non-leader member of the thread
262 * group, and the leader is zombie, then notify the
263 * group leader's parent process. (if it wants notification.)
266 leader = p->group_leader;
267 if (leader != p && thread_group_empty(leader)
268 && leader->exit_state == EXIT_ZOMBIE) {
270 * If we were the last child thread and the leader has
271 * exited already, and the leader's parent ignores SIGCHLD,
272 * then we are the one who should release the leader.
274 zap_leader = do_notify_parent(leader, leader->exit_signal);
276 leader->exit_state = EXIT_DEAD;
279 write_unlock_irq(&tasklist_lock);
280 seccomp_filter_release(p);
281 proc_flush_pid(thread_pid);
284 put_task_struct_rcu_user(p);
287 if (unlikely(zap_leader))
291 int rcuwait_wake_up(struct rcuwait *w)
294 struct task_struct *task;
299 * Order condition vs @task, such that everything prior to the load
300 * of @task is visible. This is the condition as to why the user called
301 * rcuwait_wake() in the first place. Pairs with set_current_state()
302 * barrier (A) in rcuwait_wait_event().
305 * [S] tsk = current [S] cond = true
311 task = rcu_dereference(w->task);
313 ret = wake_up_process(task);
318 EXPORT_SYMBOL_GPL(rcuwait_wake_up);
321 * Determine if a process group is "orphaned", according to the POSIX
322 * definition in 2.2.2.52. Orphaned process groups are not to be affected
323 * by terminal-generated stop signals. Newly orphaned process groups are
324 * to receive a SIGHUP and a SIGCONT.
326 * "I ask you, have you ever known what it is to be an orphan?"
328 static int will_become_orphaned_pgrp(struct pid *pgrp,
329 struct task_struct *ignored_task)
331 struct task_struct *p;
333 do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
334 if ((p == ignored_task) ||
335 (p->exit_state && thread_group_empty(p)) ||
336 is_global_init(p->real_parent))
339 if (task_pgrp(p->real_parent) != pgrp &&
340 task_session(p->real_parent) == task_session(p))
342 } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
347 int is_current_pgrp_orphaned(void)
351 read_lock(&tasklist_lock);
352 retval = will_become_orphaned_pgrp(task_pgrp(current), NULL);
353 read_unlock(&tasklist_lock);
358 static bool has_stopped_jobs(struct pid *pgrp)
360 struct task_struct *p;
362 do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
363 if (p->signal->flags & SIGNAL_STOP_STOPPED)
365 } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
371 * Check to see if any process groups have become orphaned as
372 * a result of our exiting, and if they have any stopped jobs,
373 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
376 kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
378 struct pid *pgrp = task_pgrp(tsk);
379 struct task_struct *ignored_task = tsk;
382 /* exit: our father is in a different pgrp than
383 * we are and we were the only connection outside.
385 parent = tsk->real_parent;
387 /* reparent: our child is in a different pgrp than
388 * we are, and it was the only connection outside.
392 if (task_pgrp(parent) != pgrp &&
393 task_session(parent) == task_session(tsk) &&
394 will_become_orphaned_pgrp(pgrp, ignored_task) &&
395 has_stopped_jobs(pgrp)) {
396 __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
397 __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
401 static void coredump_task_exit(struct task_struct *tsk)
403 struct core_state *core_state;
406 * Serialize with any possible pending coredump.
407 * We must hold siglock around checking core_state
408 * and setting PF_POSTCOREDUMP. The core-inducing thread
409 * will increment ->nr_threads for each thread in the
410 * group without PF_POSTCOREDUMP set.
412 spin_lock_irq(&tsk->sighand->siglock);
413 tsk->flags |= PF_POSTCOREDUMP;
414 core_state = tsk->signal->core_state;
415 spin_unlock_irq(&tsk->sighand->siglock);
417 /* The vhost_worker does not particpate in coredumps */
419 ((tsk->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER)) {
420 struct core_thread self;
423 if (self.task->flags & PF_SIGNALED)
424 self.next = xchg(&core_state->dumper.next, &self);
428 * Implies mb(), the result of xchg() must be visible
429 * to core_state->dumper.
431 if (atomic_dec_and_test(&core_state->nr_threads))
432 complete(&core_state->startup);
435 set_current_state(TASK_UNINTERRUPTIBLE|TASK_FREEZABLE);
436 if (!self.task) /* see coredump_finish() */
440 __set_current_state(TASK_RUNNING);
446 * A task is exiting. If it owned this mm, find a new owner for the mm.
448 void mm_update_next_owner(struct mm_struct *mm)
450 struct task_struct *c, *g, *p = current;
454 * If the exiting or execing task is not the owner, it's
455 * someone else's problem.
460 * The current owner is exiting/execing and there are no other
461 * candidates. Do not leave the mm pointing to a possibly
462 * freed task structure.
464 if (atomic_read(&mm->mm_users) <= 1) {
465 WRITE_ONCE(mm->owner, NULL);
469 read_lock(&tasklist_lock);
471 * Search in the children
473 list_for_each_entry(c, &p->children, sibling) {
475 goto assign_new_owner;
479 * Search in the siblings
481 list_for_each_entry(c, &p->real_parent->children, sibling) {
483 goto assign_new_owner;
487 * Search through everything else, we should not get here often.
489 for_each_process(g) {
490 if (g->flags & PF_KTHREAD)
492 for_each_thread(g, c) {
494 goto assign_new_owner;
499 read_unlock(&tasklist_lock);
501 * We found no owner yet mm_users > 1: this implies that we are
502 * most likely racing with swapoff (try_to_unuse()) or /proc or
503 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
505 WRITE_ONCE(mm->owner, NULL);
512 * The task_lock protects c->mm from changing.
513 * We always want mm->owner->mm == mm
517 * Delay read_unlock() till we have the task_lock()
518 * to ensure that c does not slip away underneath us
520 read_unlock(&tasklist_lock);
526 WRITE_ONCE(mm->owner, c);
527 lru_gen_migrate_mm(mm);
531 #endif /* CONFIG_MEMCG */
534 * Turn us into a lazy TLB process if we
537 static void exit_mm(void)
539 struct mm_struct *mm = current->mm;
541 exit_mm_release(current, mm);
546 BUG_ON(mm != current->active_mm);
547 /* more a memory barrier than a real lock */
550 * When a thread stops operating on an address space, the loop
551 * in membarrier_private_expedited() may not observe that
552 * tsk->mm, and the loop in membarrier_global_expedited() may
553 * not observe a MEMBARRIER_STATE_GLOBAL_EXPEDITED
554 * rq->membarrier_state, so those would not issue an IPI.
555 * Membarrier requires a memory barrier after accessing
556 * user-space memory, before clearing tsk->mm or the
557 * rq->membarrier_state.
559 smp_mb__after_spinlock();
562 membarrier_update_current_mm(NULL);
563 enter_lazy_tlb(mm, current);
565 task_unlock(current);
566 mmap_read_unlock(mm);
567 mm_update_next_owner(mm);
569 if (test_thread_flag(TIF_MEMDIE))
573 static struct task_struct *find_alive_thread(struct task_struct *p)
575 struct task_struct *t;
577 for_each_thread(p, t) {
578 if (!(t->flags & PF_EXITING))
584 static struct task_struct *find_child_reaper(struct task_struct *father,
585 struct list_head *dead)
586 __releases(&tasklist_lock)
587 __acquires(&tasklist_lock)
589 struct pid_namespace *pid_ns = task_active_pid_ns(father);
590 struct task_struct *reaper = pid_ns->child_reaper;
591 struct task_struct *p, *n;
593 if (likely(reaper != father))
596 reaper = find_alive_thread(father);
598 pid_ns->child_reaper = reaper;
602 write_unlock_irq(&tasklist_lock);
604 list_for_each_entry_safe(p, n, dead, ptrace_entry) {
605 list_del_init(&p->ptrace_entry);
609 zap_pid_ns_processes(pid_ns);
610 write_lock_irq(&tasklist_lock);
616 * When we die, we re-parent all our children, and try to:
617 * 1. give them to another thread in our thread group, if such a member exists
618 * 2. give it to the first ancestor process which prctl'd itself as a
619 * child_subreaper for its children (like a service manager)
620 * 3. give it to the init process (PID 1) in our pid namespace
622 static struct task_struct *find_new_reaper(struct task_struct *father,
623 struct task_struct *child_reaper)
625 struct task_struct *thread, *reaper;
627 thread = find_alive_thread(father);
631 if (father->signal->has_child_subreaper) {
632 unsigned int ns_level = task_pid(father)->level;
634 * Find the first ->is_child_subreaper ancestor in our pid_ns.
635 * We can't check reaper != child_reaper to ensure we do not
636 * cross the namespaces, the exiting parent could be injected
637 * by setns() + fork().
638 * We check pid->level, this is slightly more efficient than
639 * task_active_pid_ns(reaper) != task_active_pid_ns(father).
641 for (reaper = father->real_parent;
642 task_pid(reaper)->level == ns_level;
643 reaper = reaper->real_parent) {
644 if (reaper == &init_task)
646 if (!reaper->signal->is_child_subreaper)
648 thread = find_alive_thread(reaper);
658 * Any that need to be release_task'd are put on the @dead list.
660 static void reparent_leader(struct task_struct *father, struct task_struct *p,
661 struct list_head *dead)
663 if (unlikely(p->exit_state == EXIT_DEAD))
666 /* We don't want people slaying init. */
667 p->exit_signal = SIGCHLD;
669 /* If it has exited notify the new parent about this child's death. */
671 p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
672 if (do_notify_parent(p, p->exit_signal)) {
673 p->exit_state = EXIT_DEAD;
674 list_add(&p->ptrace_entry, dead);
678 kill_orphaned_pgrp(p, father);
682 * This does two things:
684 * A. Make init inherit all the child processes
685 * B. Check to see if any process groups have become orphaned
686 * as a result of our exiting, and if they have any stopped
687 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
689 static void forget_original_parent(struct task_struct *father,
690 struct list_head *dead)
692 struct task_struct *p, *t, *reaper;
694 if (unlikely(!list_empty(&father->ptraced)))
695 exit_ptrace(father, dead);
697 /* Can drop and reacquire tasklist_lock */
698 reaper = find_child_reaper(father, dead);
699 if (list_empty(&father->children))
702 reaper = find_new_reaper(father, reaper);
703 list_for_each_entry(p, &father->children, sibling) {
704 for_each_thread(p, t) {
705 RCU_INIT_POINTER(t->real_parent, reaper);
706 BUG_ON((!t->ptrace) != (rcu_access_pointer(t->parent) == father));
707 if (likely(!t->ptrace))
708 t->parent = t->real_parent;
709 if (t->pdeath_signal)
710 group_send_sig_info(t->pdeath_signal,
715 * If this is a threaded reparent there is no need to
716 * notify anyone anything has happened.
718 if (!same_thread_group(reaper, father))
719 reparent_leader(father, p, dead);
721 list_splice_tail_init(&father->children, &reaper->children);
725 * Send signals to all our closest relatives so that they know
726 * to properly mourn us..
728 static void exit_notify(struct task_struct *tsk, int group_dead)
731 struct task_struct *p, *n;
734 write_lock_irq(&tasklist_lock);
735 forget_original_parent(tsk, &dead);
738 kill_orphaned_pgrp(tsk->group_leader, NULL);
740 tsk->exit_state = EXIT_ZOMBIE;
742 * sub-thread or delay_group_leader(), wake up the
743 * PIDFD_THREAD waiters.
745 if (!thread_group_empty(tsk))
746 do_notify_pidfd(tsk);
748 if (unlikely(tsk->ptrace)) {
749 int sig = thread_group_leader(tsk) &&
750 thread_group_empty(tsk) &&
751 !ptrace_reparented(tsk) ?
752 tsk->exit_signal : SIGCHLD;
753 autoreap = do_notify_parent(tsk, sig);
754 } else if (thread_group_leader(tsk)) {
755 autoreap = thread_group_empty(tsk) &&
756 do_notify_parent(tsk, tsk->exit_signal);
762 tsk->exit_state = EXIT_DEAD;
763 list_add(&tsk->ptrace_entry, &dead);
766 /* mt-exec, de_thread() is waiting for group leader */
767 if (unlikely(tsk->signal->notify_count < 0))
768 wake_up_process(tsk->signal->group_exec_task);
769 write_unlock_irq(&tasklist_lock);
771 list_for_each_entry_safe(p, n, &dead, ptrace_entry) {
772 list_del_init(&p->ptrace_entry);
777 #ifdef CONFIG_DEBUG_STACK_USAGE
778 static void check_stack_usage(void)
780 static DEFINE_SPINLOCK(low_water_lock);
781 static int lowest_to_date = THREAD_SIZE;
784 free = stack_not_used(current);
786 if (free >= lowest_to_date)
789 spin_lock(&low_water_lock);
790 if (free < lowest_to_date) {
791 pr_info("%s (%d) used greatest stack depth: %lu bytes left\n",
792 current->comm, task_pid_nr(current), free);
793 lowest_to_date = free;
795 spin_unlock(&low_water_lock);
798 static inline void check_stack_usage(void) {}
801 static void synchronize_group_exit(struct task_struct *tsk, long code)
803 struct sighand_struct *sighand = tsk->sighand;
804 struct signal_struct *signal = tsk->signal;
806 spin_lock_irq(&sighand->siglock);
807 signal->quick_threads--;
808 if ((signal->quick_threads == 0) &&
809 !(signal->flags & SIGNAL_GROUP_EXIT)) {
810 signal->flags = SIGNAL_GROUP_EXIT;
811 signal->group_exit_code = code;
812 signal->group_stop_count = 0;
814 spin_unlock_irq(&sighand->siglock);
817 void __noreturn do_exit(long code)
819 struct task_struct *tsk = current;
822 WARN_ON(irqs_disabled());
824 synchronize_group_exit(tsk, code);
829 kmsan_task_exit(tsk);
831 coredump_task_exit(tsk);
832 ptrace_event(PTRACE_EVENT_EXIT, code);
833 user_events_exit(tsk);
835 io_uring_files_cancel();
836 exit_signals(tsk); /* sets PF_EXITING */
838 acct_update_integrals(tsk);
839 group_dead = atomic_dec_and_test(&tsk->signal->live);
842 * If the last thread of global init has exited, panic
843 * immediately to get a useable coredump.
845 if (unlikely(is_global_init(tsk)))
846 panic("Attempted to kill init! exitcode=0x%08x\n",
847 tsk->signal->group_exit_code ?: (int)code);
849 #ifdef CONFIG_POSIX_TIMERS
850 hrtimer_cancel(&tsk->signal->real_timer);
854 setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
856 acct_collect(code, group_dead);
861 tsk->exit_code = code;
862 taskstats_exit(tsk, group_dead);
868 trace_sched_process_exit(tsk);
875 disassociate_ctty(1);
876 exit_task_namespaces(tsk);
881 * Flush inherited counters to the parent - before the parent
882 * gets woken up by child-exit notifications.
884 * because of cgroup mode, must be called before cgroup_exit()
886 perf_event_exit_task(tsk);
888 sched_autogroup_exit_task(tsk);
892 * FIXME: do that only when needed, using sched_exit tracepoint
894 flush_ptrace_hw_breakpoint(tsk);
896 exit_tasks_rcu_start();
897 exit_notify(tsk, group_dead);
898 proc_exit_connector(tsk);
899 mpol_put_task_policy(tsk);
901 if (unlikely(current->pi_state_cache))
902 kfree(current->pi_state_cache);
905 * Make sure we are holding no locks:
907 debug_check_no_locks_held();
910 exit_io_context(tsk);
912 if (tsk->splice_pipe)
913 free_pipe_info(tsk->splice_pipe);
915 if (tsk->task_frag.page)
916 put_page(tsk->task_frag.page);
918 exit_task_stack_account(tsk);
923 __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
925 exit_tasks_rcu_finish();
927 lockdep_free_task(tsk);
931 void __noreturn make_task_dead(int signr)
934 * Take the task off the cpu after something catastrophic has
937 * We can get here from a kernel oops, sometimes with preemption off.
938 * Start by checking for critical errors.
939 * Then fix up important state like USER_DS and preemption.
940 * Then do everything else.
942 struct task_struct *tsk = current;
945 if (unlikely(in_interrupt()))
946 panic("Aiee, killing interrupt handler!");
947 if (unlikely(!tsk->pid))
948 panic("Attempted to kill the idle task!");
950 if (unlikely(irqs_disabled())) {
951 pr_info("note: %s[%d] exited with irqs disabled\n",
952 current->comm, task_pid_nr(current));
955 if (unlikely(in_atomic())) {
956 pr_info("note: %s[%d] exited with preempt_count %d\n",
957 current->comm, task_pid_nr(current),
959 preempt_count_set(PREEMPT_ENABLED);
963 * Every time the system oopses, if the oops happens while a reference
964 * to an object was held, the reference leaks.
965 * If the oops doesn't also leak memory, repeated oopsing can cause
966 * reference counters to wrap around (if they're not using refcount_t).
967 * This means that repeated oopsing can make unexploitable-looking bugs
968 * exploitable through repeated oopsing.
969 * To make sure this can't happen, place an upper bound on how often the
970 * kernel may oops without panic().
972 limit = READ_ONCE(oops_limit);
973 if (atomic_inc_return(&oops_count) >= limit && limit)
974 panic("Oopsed too often (kernel.oops_limit is %d)", limit);
977 * We're taking recursive faults here in make_task_dead. Safest is to just
978 * leave this task alone and wait for reboot.
980 if (unlikely(tsk->flags & PF_EXITING)) {
981 pr_alert("Fixing recursive fault but reboot is needed!\n");
982 futex_exit_recursive(tsk);
983 tsk->exit_state = EXIT_DEAD;
984 refcount_inc(&tsk->rcu_users);
991 SYSCALL_DEFINE1(exit, int, error_code)
993 do_exit((error_code&0xff)<<8);
997 * Take down every thread in the group. This is called by fatal signals
998 * as well as by sys_exit_group (below).
1001 do_group_exit(int exit_code)
1003 struct signal_struct *sig = current->signal;
1005 if (sig->flags & SIGNAL_GROUP_EXIT)
1006 exit_code = sig->group_exit_code;
1007 else if (sig->group_exec_task)
1010 struct sighand_struct *const sighand = current->sighand;
1012 spin_lock_irq(&sighand->siglock);
1013 if (sig->flags & SIGNAL_GROUP_EXIT)
1014 /* Another thread got here before we took the lock. */
1015 exit_code = sig->group_exit_code;
1016 else if (sig->group_exec_task)
1019 sig->group_exit_code = exit_code;
1020 sig->flags = SIGNAL_GROUP_EXIT;
1021 zap_other_threads(current);
1023 spin_unlock_irq(&sighand->siglock);
1031 * this kills every thread in the thread group. Note that any externally
1032 * wait4()-ing process will get the correct exit code - even if this
1033 * thread is not the thread group leader.
1035 SYSCALL_DEFINE1(exit_group, int, error_code)
1037 do_group_exit((error_code & 0xff) << 8);
1042 static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
1044 return wo->wo_type == PIDTYPE_MAX ||
1045 task_pid_type(p, wo->wo_type) == wo->wo_pid;
1049 eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
1051 if (!eligible_pid(wo, p))
1055 * Wait for all children (clone and not) if __WALL is set or
1056 * if it is traced by us.
1058 if (ptrace || (wo->wo_flags & __WALL))
1062 * Otherwise, wait for clone children *only* if __WCLONE is set;
1063 * otherwise, wait for non-clone children *only*.
1065 * Note: a "clone" child here is one that reports to its parent
1066 * using a signal other than SIGCHLD, or a non-leader thread which
1067 * we can only see if it is traced by us.
1069 if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
1076 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1077 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1078 * the lock and this task is uninteresting. If we return nonzero, we have
1079 * released the lock and the system call should return.
1081 static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
1084 pid_t pid = task_pid_vnr(p);
1085 uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p));
1086 struct waitid_info *infop;
1088 if (!likely(wo->wo_flags & WEXITED))
1091 if (unlikely(wo->wo_flags & WNOWAIT)) {
1092 status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1093 ? p->signal->group_exit_code : p->exit_code;
1095 read_unlock(&tasklist_lock);
1096 sched_annotate_sleep();
1098 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1103 * Move the task's state to DEAD/TRACE, only one thread can do this.
1105 state = (ptrace_reparented(p) && thread_group_leader(p)) ?
1106 EXIT_TRACE : EXIT_DEAD;
1107 if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)
1110 * We own this thread, nobody else can reap it.
1112 read_unlock(&tasklist_lock);
1113 sched_annotate_sleep();
1116 * Check thread_group_leader() to exclude the traced sub-threads.
1118 if (state == EXIT_DEAD && thread_group_leader(p)) {
1119 struct signal_struct *sig = p->signal;
1120 struct signal_struct *psig = current->signal;
1121 unsigned long maxrss;
1122 u64 tgutime, tgstime;
1125 * The resource counters for the group leader are in its
1126 * own task_struct. Those for dead threads in the group
1127 * are in its signal_struct, as are those for the child
1128 * processes it has previously reaped. All these
1129 * accumulate in the parent's signal_struct c* fields.
1131 * We don't bother to take a lock here to protect these
1132 * p->signal fields because the whole thread group is dead
1133 * and nobody can change them.
1135 * psig->stats_lock also protects us from our sub-threads
1136 * which can reap other children at the same time.
1138 * We use thread_group_cputime_adjusted() to get times for
1139 * the thread group, which consolidates times for all threads
1140 * in the group including the group leader.
1142 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1143 write_seqlock_irq(&psig->stats_lock);
1144 psig->cutime += tgutime + sig->cutime;
1145 psig->cstime += tgstime + sig->cstime;
1146 psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime;
1148 p->min_flt + sig->min_flt + sig->cmin_flt;
1150 p->maj_flt + sig->maj_flt + sig->cmaj_flt;
1152 p->nvcsw + sig->nvcsw + sig->cnvcsw;
1154 p->nivcsw + sig->nivcsw + sig->cnivcsw;
1156 task_io_get_inblock(p) +
1157 sig->inblock + sig->cinblock;
1159 task_io_get_oublock(p) +
1160 sig->oublock + sig->coublock;
1161 maxrss = max(sig->maxrss, sig->cmaxrss);
1162 if (psig->cmaxrss < maxrss)
1163 psig->cmaxrss = maxrss;
1164 task_io_accounting_add(&psig->ioac, &p->ioac);
1165 task_io_accounting_add(&psig->ioac, &sig->ioac);
1166 write_sequnlock_irq(&psig->stats_lock);
1170 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1171 status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1172 ? p->signal->group_exit_code : p->exit_code;
1173 wo->wo_stat = status;
1175 if (state == EXIT_TRACE) {
1176 write_lock_irq(&tasklist_lock);
1177 /* We dropped tasklist, ptracer could die and untrace */
1180 /* If parent wants a zombie, don't release it now */
1181 state = EXIT_ZOMBIE;
1182 if (do_notify_parent(p, p->exit_signal))
1184 p->exit_state = state;
1185 write_unlock_irq(&tasklist_lock);
1187 if (state == EXIT_DEAD)
1191 infop = wo->wo_info;
1193 if ((status & 0x7f) == 0) {
1194 infop->cause = CLD_EXITED;
1195 infop->status = status >> 8;
1197 infop->cause = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
1198 infop->status = status & 0x7f;
1207 static int *task_stopped_code(struct task_struct *p, bool ptrace)
1210 if (task_is_traced(p) && !(p->jobctl & JOBCTL_LISTENING))
1211 return &p->exit_code;
1213 if (p->signal->flags & SIGNAL_STOP_STOPPED)
1214 return &p->signal->group_exit_code;
1220 * wait_task_stopped - Wait for %TASK_STOPPED or %TASK_TRACED
1222 * @ptrace: is the wait for ptrace
1223 * @p: task to wait for
1225 * Handle sys_wait4() work for %p in state %TASK_STOPPED or %TASK_TRACED.
1228 * read_lock(&tasklist_lock), which is released if return value is
1229 * non-zero. Also, grabs and releases @p->sighand->siglock.
1232 * 0 if wait condition didn't exist and search for other wait conditions
1233 * should continue. Non-zero return, -errno on failure and @p's pid on
1234 * success, implies that tasklist_lock is released and wait condition
1235 * search should terminate.
1237 static int wait_task_stopped(struct wait_opts *wo,
1238 int ptrace, struct task_struct *p)
1240 struct waitid_info *infop;
1241 int exit_code, *p_code, why;
1242 uid_t uid = 0; /* unneeded, required by compiler */
1246 * Traditionally we see ptrace'd stopped tasks regardless of options.
1248 if (!ptrace && !(wo->wo_flags & WUNTRACED))
1251 if (!task_stopped_code(p, ptrace))
1255 spin_lock_irq(&p->sighand->siglock);
1257 p_code = task_stopped_code(p, ptrace);
1258 if (unlikely(!p_code))
1261 exit_code = *p_code;
1265 if (!unlikely(wo->wo_flags & WNOWAIT))
1268 uid = from_kuid_munged(current_user_ns(), task_uid(p));
1270 spin_unlock_irq(&p->sighand->siglock);
1275 * Now we are pretty sure this task is interesting.
1276 * Make sure it doesn't get reaped out from under us while we
1277 * give up the lock and then examine it below. We don't want to
1278 * keep holding onto the tasklist_lock while we call getrusage and
1279 * possibly take page faults for user memory.
1282 pid = task_pid_vnr(p);
1283 why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
1284 read_unlock(&tasklist_lock);
1285 sched_annotate_sleep();
1287 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1290 if (likely(!(wo->wo_flags & WNOWAIT)))
1291 wo->wo_stat = (exit_code << 8) | 0x7f;
1293 infop = wo->wo_info;
1296 infop->status = exit_code;
1304 * Handle do_wait work for one task in a live, non-stopped state.
1305 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1306 * the lock and this task is uninteresting. If we return nonzero, we have
1307 * released the lock and the system call should return.
1309 static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
1311 struct waitid_info *infop;
1315 if (!unlikely(wo->wo_flags & WCONTINUED))
1318 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
1321 spin_lock_irq(&p->sighand->siglock);
1322 /* Re-check with the lock held. */
1323 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
1324 spin_unlock_irq(&p->sighand->siglock);
1327 if (!unlikely(wo->wo_flags & WNOWAIT))
1328 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
1329 uid = from_kuid_munged(current_user_ns(), task_uid(p));
1330 spin_unlock_irq(&p->sighand->siglock);
1332 pid = task_pid_vnr(p);
1334 read_unlock(&tasklist_lock);
1335 sched_annotate_sleep();
1337 getrusage(p, RUSAGE_BOTH, wo->wo_rusage);
1340 infop = wo->wo_info;
1342 wo->wo_stat = 0xffff;
1344 infop->cause = CLD_CONTINUED;
1347 infop->status = SIGCONT;
1353 * Consider @p for a wait by @parent.
1355 * -ECHILD should be in ->notask_error before the first call.
1356 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1357 * Returns zero if the search for a child should continue;
1358 * then ->notask_error is 0 if @p is an eligible child,
1361 static int wait_consider_task(struct wait_opts *wo, int ptrace,
1362 struct task_struct *p)
1365 * We can race with wait_task_zombie() from another thread.
1366 * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
1367 * can't confuse the checks below.
1369 int exit_state = READ_ONCE(p->exit_state);
1372 if (unlikely(exit_state == EXIT_DEAD))
1375 ret = eligible_child(wo, ptrace, p);
1379 if (unlikely(exit_state == EXIT_TRACE)) {
1381 * ptrace == 0 means we are the natural parent. In this case
1382 * we should clear notask_error, debugger will notify us.
1384 if (likely(!ptrace))
1385 wo->notask_error = 0;
1389 if (likely(!ptrace) && unlikely(p->ptrace)) {
1391 * If it is traced by its real parent's group, just pretend
1392 * the caller is ptrace_do_wait() and reap this child if it
1395 * This also hides group stop state from real parent; otherwise
1396 * a single stop can be reported twice as group and ptrace stop.
1397 * If a ptracer wants to distinguish these two events for its
1398 * own children it should create a separate process which takes
1399 * the role of real parent.
1401 if (!ptrace_reparented(p))
1406 if (exit_state == EXIT_ZOMBIE) {
1407 /* we don't reap group leaders with subthreads */
1408 if (!delay_group_leader(p)) {
1410 * A zombie ptracee is only visible to its ptracer.
1411 * Notification and reaping will be cascaded to the
1412 * real parent when the ptracer detaches.
1414 if (unlikely(ptrace) || likely(!p->ptrace))
1415 return wait_task_zombie(wo, p);
1419 * Allow access to stopped/continued state via zombie by
1420 * falling through. Clearing of notask_error is complex.
1424 * If WEXITED is set, notask_error should naturally be
1425 * cleared. If not, subset of WSTOPPED|WCONTINUED is set,
1426 * so, if there are live subthreads, there are events to
1427 * wait for. If all subthreads are dead, it's still safe
1428 * to clear - this function will be called again in finite
1429 * amount time once all the subthreads are released and
1430 * will then return without clearing.
1434 * Stopped state is per-task and thus can't change once the
1435 * target task dies. Only continued and exited can happen.
1436 * Clear notask_error if WCONTINUED | WEXITED.
1438 if (likely(!ptrace) || (wo->wo_flags & (WCONTINUED | WEXITED)))
1439 wo->notask_error = 0;
1442 * @p is alive and it's gonna stop, continue or exit, so
1443 * there always is something to wait for.
1445 wo->notask_error = 0;
1449 * Wait for stopped. Depending on @ptrace, different stopped state
1450 * is used and the two don't interact with each other.
1452 ret = wait_task_stopped(wo, ptrace, p);
1457 * Wait for continued. There's only one continued state and the
1458 * ptracer can consume it which can confuse the real parent. Don't
1459 * use WCONTINUED from ptracer. You don't need or want it.
1461 return wait_task_continued(wo, p);
1465 * Do the work of do_wait() for one thread in the group, @tsk.
1467 * -ECHILD should be in ->notask_error before the first call.
1468 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1469 * Returns zero if the search for a child should continue; then
1470 * ->notask_error is 0 if there were any eligible children,
1473 static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk)
1475 struct task_struct *p;
1477 list_for_each_entry(p, &tsk->children, sibling) {
1478 int ret = wait_consider_task(wo, 0, p);
1487 static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk)
1489 struct task_struct *p;
1491 list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
1492 int ret = wait_consider_task(wo, 1, p);
1501 bool pid_child_should_wake(struct wait_opts *wo, struct task_struct *p)
1503 if (!eligible_pid(wo, p))
1506 if ((wo->wo_flags & __WNOTHREAD) && wo->child_wait.private != p->parent)
1512 static int child_wait_callback(wait_queue_entry_t *wait, unsigned mode,
1513 int sync, void *key)
1515 struct wait_opts *wo = container_of(wait, struct wait_opts,
1517 struct task_struct *p = key;
1519 if (pid_child_should_wake(wo, p))
1520 return default_wake_function(wait, mode, sync, key);
1525 void __wake_up_parent(struct task_struct *p, struct task_struct *parent)
1527 __wake_up_sync_key(&parent->signal->wait_chldexit,
1528 TASK_INTERRUPTIBLE, p);
1531 static bool is_effectively_child(struct wait_opts *wo, bool ptrace,
1532 struct task_struct *target)
1534 struct task_struct *parent =
1535 !ptrace ? target->real_parent : target->parent;
1537 return current == parent || (!(wo->wo_flags & __WNOTHREAD) &&
1538 same_thread_group(current, parent));
1542 * Optimization for waiting on PIDTYPE_PID. No need to iterate through child
1543 * and tracee lists to find the target task.
1545 static int do_wait_pid(struct wait_opts *wo)
1548 struct task_struct *target;
1552 target = pid_task(wo->wo_pid, PIDTYPE_TGID);
1553 if (target && is_effectively_child(wo, ptrace, target)) {
1554 retval = wait_consider_task(wo, ptrace, target);
1560 target = pid_task(wo->wo_pid, PIDTYPE_PID);
1561 if (target && target->ptrace &&
1562 is_effectively_child(wo, ptrace, target)) {
1563 retval = wait_consider_task(wo, ptrace, target);
1571 long __do_wait(struct wait_opts *wo)
1576 * If there is nothing that can match our criteria, just get out.
1577 * We will clear ->notask_error to zero if we see any child that
1578 * might later match our criteria, even if we are not able to reap
1581 wo->notask_error = -ECHILD;
1582 if ((wo->wo_type < PIDTYPE_MAX) &&
1583 (!wo->wo_pid || !pid_has_task(wo->wo_pid, wo->wo_type)))
1586 read_lock(&tasklist_lock);
1588 if (wo->wo_type == PIDTYPE_PID) {
1589 retval = do_wait_pid(wo);
1593 struct task_struct *tsk = current;
1596 retval = do_wait_thread(wo, tsk);
1600 retval = ptrace_do_wait(wo, tsk);
1604 if (wo->wo_flags & __WNOTHREAD)
1606 } while_each_thread(current, tsk);
1608 read_unlock(&tasklist_lock);
1611 retval = wo->notask_error;
1612 if (!retval && !(wo->wo_flags & WNOHANG))
1613 return -ERESTARTSYS;
1618 static long do_wait(struct wait_opts *wo)
1622 trace_sched_process_wait(wo->wo_pid);
1624 init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);
1625 wo->child_wait.private = current;
1626 add_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
1629 set_current_state(TASK_INTERRUPTIBLE);
1630 retval = __do_wait(wo);
1631 if (retval != -ERESTARTSYS)
1633 if (signal_pending(current))
1638 __set_current_state(TASK_RUNNING);
1639 remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait);
1643 int kernel_waitid_prepare(struct wait_opts *wo, int which, pid_t upid,
1644 struct waitid_info *infop, int options,
1647 unsigned int f_flags = 0;
1648 struct pid *pid = NULL;
1651 if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
1652 __WNOTHREAD|__WCLONE|__WALL))
1654 if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
1666 pid = find_get_pid(upid);
1669 type = PIDTYPE_PGID;
1674 pid = find_get_pid(upid);
1676 pid = get_task_pid(current, PIDTYPE_PGID);
1683 pid = pidfd_get_pid(upid, &f_flags);
1685 return PTR_ERR(pid);
1694 wo->wo_flags = options;
1695 wo->wo_info = infop;
1697 if (f_flags & O_NONBLOCK)
1698 wo->wo_flags |= WNOHANG;
1703 static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
1704 int options, struct rusage *ru)
1706 struct wait_opts wo;
1709 ret = kernel_waitid_prepare(&wo, which, upid, infop, options, ru);
1714 if (!ret && !(options & WNOHANG) && (wo.wo_flags & WNOHANG))
1721 SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *,
1722 infop, int, options, struct rusage __user *, ru)
1725 struct waitid_info info = {.status = 0};
1726 long err = kernel_waitid(which, upid, &info, options, ru ? &r : NULL);
1732 if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
1738 if (!user_write_access_begin(infop, sizeof(*infop)))
1741 unsafe_put_user(signo, &infop->si_signo, Efault);
1742 unsafe_put_user(0, &infop->si_errno, Efault);
1743 unsafe_put_user(info.cause, &infop->si_code, Efault);
1744 unsafe_put_user(info.pid, &infop->si_pid, Efault);
1745 unsafe_put_user(info.uid, &infop->si_uid, Efault);
1746 unsafe_put_user(info.status, &infop->si_status, Efault);
1747 user_write_access_end();
1750 user_write_access_end();
1754 long kernel_wait4(pid_t upid, int __user *stat_addr, int options,
1757 struct wait_opts wo;
1758 struct pid *pid = NULL;
1762 if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
1763 __WNOTHREAD|__WCLONE|__WALL))
1766 /* -INT_MIN is not defined */
1767 if (upid == INT_MIN)
1772 else if (upid < 0) {
1773 type = PIDTYPE_PGID;
1774 pid = find_get_pid(-upid);
1775 } else if (upid == 0) {
1776 type = PIDTYPE_PGID;
1777 pid = get_task_pid(current, PIDTYPE_PGID);
1778 } else /* upid > 0 */ {
1780 pid = find_get_pid(upid);
1785 wo.wo_flags = options | WEXITED;
1791 if (ret > 0 && stat_addr && put_user(wo.wo_stat, stat_addr))
1797 int kernel_wait(pid_t pid, int *stat)
1799 struct wait_opts wo = {
1800 .wo_type = PIDTYPE_PID,
1801 .wo_pid = find_get_pid(pid),
1802 .wo_flags = WEXITED,
1807 if (ret > 0 && wo.wo_stat)
1813 SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
1814 int, options, struct rusage __user *, ru)
1817 long err = kernel_wait4(upid, stat_addr, options, ru ? &r : NULL);
1820 if (ru && copy_to_user(ru, &r, sizeof(struct rusage)))
1826 #ifdef __ARCH_WANT_SYS_WAITPID
1829 * sys_waitpid() remains for compatibility. waitpid() should be
1830 * implemented by calling sys_wait4() from libc.a.
1832 SYSCALL_DEFINE3(waitpid, pid_t, pid, int __user *, stat_addr, int, options)
1834 return kernel_wait4(pid, stat_addr, options, NULL);
1839 #ifdef CONFIG_COMPAT
1840 COMPAT_SYSCALL_DEFINE4(wait4,
1842 compat_uint_t __user *, stat_addr,
1844 struct compat_rusage __user *, ru)
1847 long err = kernel_wait4(pid, stat_addr, options, ru ? &r : NULL);
1849 if (ru && put_compat_rusage(&r, ru))
1855 COMPAT_SYSCALL_DEFINE5(waitid,
1856 int, which, compat_pid_t, pid,
1857 struct compat_siginfo __user *, infop, int, options,
1858 struct compat_rusage __user *, uru)
1861 struct waitid_info info = {.status = 0};
1862 long err = kernel_waitid(which, pid, &info, options, uru ? &ru : NULL);
1868 /* kernel_waitid() overwrites everything in ru */
1869 if (COMPAT_USE_64BIT_TIME)
1870 err = copy_to_user(uru, &ru, sizeof(ru));
1872 err = put_compat_rusage(&ru, uru);
1881 if (!user_write_access_begin(infop, sizeof(*infop)))
1884 unsafe_put_user(signo, &infop->si_signo, Efault);
1885 unsafe_put_user(0, &infop->si_errno, Efault);
1886 unsafe_put_user(info.cause, &infop->si_code, Efault);
1887 unsafe_put_user(info.pid, &infop->si_pid, Efault);
1888 unsafe_put_user(info.uid, &infop->si_uid, Efault);
1889 unsafe_put_user(info.status, &infop->si_status, Efault);
1890 user_write_access_end();
1893 user_write_access_end();
1899 * This needs to be __function_aligned as GCC implicitly makes any
1900 * implementation of abort() cold and drops alignment specified by
1901 * -falign-functions=N.
1903 * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345#c11
1905 __weak __function_aligned void abort(void)
1909 /* if that doesn't kill us, halt */
1910 panic("Oops failed to kill thread");
1912 EXPORT_SYMBOL(abort);