]>
git.proxmox.com Git - mirror_ubuntu-kernels.git/blob - kernel/exit.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/capability.h>
12 #include <linux/completion.h>
13 #include <linux/personality.h>
14 #include <linux/tty.h>
15 #include <linux/iocontext.h>
16 #include <linux/key.h>
17 #include <linux/cpu.h>
18 #include <linux/acct.h>
19 #include <linux/tsacct_kern.h>
20 #include <linux/file.h>
21 #include <linux/fdtable.h>
22 #include <linux/freezer.h>
23 #include <linux/binfmts.h>
24 #include <linux/nsproxy.h>
25 #include <linux/pid_namespace.h>
26 #include <linux/ptrace.h>
27 #include <linux/profile.h>
28 #include <linux/mount.h>
29 #include <linux/proc_fs.h>
30 #include <linux/kthread.h>
31 #include <linux/mempolicy.h>
32 #include <linux/taskstats_kern.h>
33 #include <linux/delayacct.h>
34 #include <linux/cgroup.h>
35 #include <linux/syscalls.h>
36 #include <linux/signal.h>
37 #include <linux/posix-timers.h>
38 #include <linux/cn_proc.h>
39 #include <linux/mutex.h>
40 #include <linux/futex.h>
41 #include <linux/pipe_fs_i.h>
42 #include <linux/audit.h> /* for audit_free() */
43 #include <linux/resource.h>
44 #include <linux/blkdev.h>
45 #include <linux/task_io_accounting_ops.h>
46 #include <linux/tracehook.h>
47 #include <linux/fs_struct.h>
48 #include <linux/userfaultfd_k.h>
49 #include <linux/init_task.h>
50 #include <linux/perf_event.h>
51 #include <trace/events/sched.h>
52 #include <linux/hw_breakpoint.h>
53 #include <linux/oom.h>
54 #include <linux/writeback.h>
55 #include <linux/shm.h>
56 #include <linux/kcov.h>
57 #include <linux/random.h>
58 #include <linux/rcuwait.h>
60 #include <linux/uaccess.h>
61 #include <asm/unistd.h>
62 #include <asm/pgtable.h>
63 #include <asm/mmu_context.h>
65 static void __unhash_process(struct task_struct
*p
, bool group_dead
)
68 detach_pid(p
, PIDTYPE_PID
);
70 detach_pid(p
, PIDTYPE_PGID
);
71 detach_pid(p
, PIDTYPE_SID
);
73 list_del_rcu(&p
->tasks
);
74 list_del_init(&p
->sibling
);
75 __this_cpu_dec(process_counts
);
77 list_del_rcu(&p
->thread_group
);
78 list_del_rcu(&p
->thread_node
);
82 * This function expects the tasklist_lock write-locked.
84 static void __exit_signal(struct task_struct
*tsk
)
86 struct signal_struct
*sig
= tsk
->signal
;
87 bool group_dead
= thread_group_leader(tsk
);
88 struct sighand_struct
*sighand
;
89 struct tty_struct
*uninitialized_var(tty
);
92 sighand
= rcu_dereference_check(tsk
->sighand
,
93 lockdep_tasklist_lock_is_held());
94 spin_lock(&sighand
->siglock
);
96 #ifdef CONFIG_POSIX_TIMERS
97 posix_cpu_timers_exit(tsk
);
99 posix_cpu_timers_exit_group(tsk
);
102 * This can only happen if the caller is de_thread().
103 * FIXME: this is the temporary hack, we should teach
104 * posix-cpu-timers to handle this case correctly.
106 if (unlikely(has_group_leader_pid(tsk
)))
107 posix_cpu_timers_exit_group(tsk
);
116 * If there is any task waiting for the group exit
119 if (sig
->notify_count
> 0 && !--sig
->notify_count
)
120 wake_up_process(sig
->group_exit_task
);
122 if (tsk
== sig
->curr_target
)
123 sig
->curr_target
= next_thread(tsk
);
126 add_device_randomness((const void*) &tsk
->se
.sum_exec_runtime
,
127 sizeof(unsigned long long));
130 * Accumulate here the counters for all threads as they die. We could
131 * skip the group leader because it is the last user of signal_struct,
132 * but we want to avoid the race with thread_group_cputime() which can
133 * see the empty ->thread_head list.
135 task_cputime(tsk
, &utime
, &stime
);
136 write_seqlock(&sig
->stats_lock
);
139 sig
->gtime
+= task_gtime(tsk
);
140 sig
->min_flt
+= tsk
->min_flt
;
141 sig
->maj_flt
+= tsk
->maj_flt
;
142 sig
->nvcsw
+= tsk
->nvcsw
;
143 sig
->nivcsw
+= tsk
->nivcsw
;
144 sig
->inblock
+= task_io_get_inblock(tsk
);
145 sig
->oublock
+= task_io_get_oublock(tsk
);
146 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
147 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
149 __unhash_process(tsk
, group_dead
);
150 write_sequnlock(&sig
->stats_lock
);
153 * Do this under ->siglock, we can race with another thread
154 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
156 flush_sigqueue(&tsk
->pending
);
158 spin_unlock(&sighand
->siglock
);
160 __cleanup_sighand(sighand
);
161 clear_tsk_thread_flag(tsk
, TIF_SIGPENDING
);
163 flush_sigqueue(&sig
->shared_pending
);
168 static void delayed_put_task_struct(struct rcu_head
*rhp
)
170 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
172 perf_event_delayed_put(tsk
);
173 trace_sched_process_free(tsk
);
174 put_task_struct(tsk
);
178 void release_task(struct task_struct
*p
)
180 struct task_struct
*leader
;
183 /* don't need to get the RCU readlock here - the process is dead and
184 * can't be modifying its own credentials. But shut RCU-lockdep up */
186 atomic_dec(&__task_cred(p
)->user
->processes
);
191 write_lock_irq(&tasklist_lock
);
192 ptrace_release_task(p
);
196 * If we are the last non-leader member of the thread
197 * group, and the leader is zombie, then notify the
198 * group leader's parent process. (if it wants notification.)
201 leader
= p
->group_leader
;
202 if (leader
!= p
&& thread_group_empty(leader
)
203 && leader
->exit_state
== EXIT_ZOMBIE
) {
205 * If we were the last child thread and the leader has
206 * exited already, and the leader's parent ignores SIGCHLD,
207 * then we are the one who should release the leader.
209 zap_leader
= do_notify_parent(leader
, leader
->exit_signal
);
211 leader
->exit_state
= EXIT_DEAD
;
214 write_unlock_irq(&tasklist_lock
);
216 call_rcu(&p
->rcu
, delayed_put_task_struct
);
219 if (unlikely(zap_leader
))
224 * Note that if this function returns a valid task_struct pointer (!NULL)
225 * task->usage must remain >0 for the duration of the RCU critical section.
227 struct task_struct
*task_rcu_dereference(struct task_struct
**ptask
)
229 struct sighand_struct
*sighand
;
230 struct task_struct
*task
;
233 * We need to verify that release_task() was not called and thus
234 * delayed_put_task_struct() can't run and drop the last reference
235 * before rcu_read_unlock(). We check task->sighand != NULL,
236 * but we can read the already freed and reused memory.
239 task
= rcu_dereference(*ptask
);
243 probe_kernel_address(&task
->sighand
, sighand
);
246 * Pairs with atomic_dec_and_test() in put_task_struct(). If this task
247 * was already freed we can not miss the preceding update of this
251 if (unlikely(task
!= READ_ONCE(*ptask
)))
255 * We've re-checked that "task == *ptask", now we have two different
258 * 1. This is actually the same task/task_struct. In this case
259 * sighand != NULL tells us it is still alive.
261 * 2. This is another task which got the same memory for task_struct.
262 * We can't know this of course, and we can not trust
265 * In this case we actually return a random value, but this is
268 * If we return NULL - we can pretend that we actually noticed that
269 * *ptask was updated when the previous task has exited. Or pretend
270 * that probe_slab_address(&sighand) reads NULL.
272 * If we return the new task (because sighand is not NULL for any
273 * reason) - this is fine too. This (new) task can't go away before
276 * And note: We could even eliminate the false positive if re-read
277 * task->sighand once again to avoid the falsely NULL. But this case
278 * is very unlikely so we don't care.
286 void rcuwait_wake_up(struct rcuwait
*w
)
288 struct task_struct
*task
;
293 * Order condition vs @task, such that everything prior to the load
294 * of @task is visible. This is the condition as to why the user called
295 * rcuwait_trywake() in the first place. Pairs with set_current_state()
296 * barrier (A) in rcuwait_wait_event().
299 * [S] tsk = current [S] cond = true
306 * Avoid using task_rcu_dereference() magic as long as we are careful,
307 * see comment in rcuwait_wait_event() regarding ->exit_state.
309 task
= rcu_dereference(w
->task
);
311 wake_up_process(task
);
315 struct task_struct
*try_get_task_struct(struct task_struct
**ptask
)
317 struct task_struct
*task
;
320 task
= task_rcu_dereference(ptask
);
322 get_task_struct(task
);
329 * Determine if a process group is "orphaned", according to the POSIX
330 * definition in 2.2.2.52. Orphaned process groups are not to be affected
331 * by terminal-generated stop signals. Newly orphaned process groups are
332 * to receive a SIGHUP and a SIGCONT.
334 * "I ask you, have you ever known what it is to be an orphan?"
336 static int will_become_orphaned_pgrp(struct pid
*pgrp
,
337 struct task_struct
*ignored_task
)
339 struct task_struct
*p
;
341 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
342 if ((p
== ignored_task
) ||
343 (p
->exit_state
&& thread_group_empty(p
)) ||
344 is_global_init(p
->real_parent
))
347 if (task_pgrp(p
->real_parent
) != pgrp
&&
348 task_session(p
->real_parent
) == task_session(p
))
350 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
355 int is_current_pgrp_orphaned(void)
359 read_lock(&tasklist_lock
);
360 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
361 read_unlock(&tasklist_lock
);
366 static bool has_stopped_jobs(struct pid
*pgrp
)
368 struct task_struct
*p
;
370 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
371 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
)
373 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
379 * Check to see if any process groups have become orphaned as
380 * a result of our exiting, and if they have any stopped jobs,
381 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
384 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
386 struct pid
*pgrp
= task_pgrp(tsk
);
387 struct task_struct
*ignored_task
= tsk
;
390 /* exit: our father is in a different pgrp than
391 * we are and we were the only connection outside.
393 parent
= tsk
->real_parent
;
395 /* reparent: our child is in a different pgrp than
396 * we are, and it was the only connection outside.
400 if (task_pgrp(parent
) != pgrp
&&
401 task_session(parent
) == task_session(tsk
) &&
402 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
403 has_stopped_jobs(pgrp
)) {
404 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
405 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
411 * A task is exiting. If it owned this mm, find a new owner for the mm.
413 void mm_update_next_owner(struct mm_struct
*mm
)
415 struct task_struct
*c
, *g
, *p
= current
;
419 * If the exiting or execing task is not the owner, it's
420 * someone else's problem.
425 * The current owner is exiting/execing and there are no other
426 * candidates. Do not leave the mm pointing to a possibly
427 * freed task structure.
429 if (atomic_read(&mm
->mm_users
) <= 1) {
434 read_lock(&tasklist_lock
);
436 * Search in the children
438 list_for_each_entry(c
, &p
->children
, sibling
) {
440 goto assign_new_owner
;
444 * Search in the siblings
446 list_for_each_entry(c
, &p
->real_parent
->children
, sibling
) {
448 goto assign_new_owner
;
452 * Search through everything else, we should not get here often.
454 for_each_process(g
) {
455 if (g
->flags
& PF_KTHREAD
)
457 for_each_thread(g
, c
) {
459 goto assign_new_owner
;
464 read_unlock(&tasklist_lock
);
466 * We found no owner yet mm_users > 1: this implies that we are
467 * most likely racing with swapoff (try_to_unuse()) or /proc or
468 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
477 * The task_lock protects c->mm from changing.
478 * We always want mm->owner->mm == mm
482 * Delay read_unlock() till we have the task_lock()
483 * to ensure that c does not slip away underneath us
485 read_unlock(&tasklist_lock
);
495 #endif /* CONFIG_MEMCG */
498 * Turn us into a lazy TLB process if we
501 static void exit_mm(void)
503 struct mm_struct
*mm
= current
->mm
;
504 struct core_state
*core_state
;
506 mm_release(current
, mm
);
511 * Serialize with any possible pending coredump.
512 * We must hold mmap_sem around checking core_state
513 * and clearing tsk->mm. The core-inducing thread
514 * will increment ->nr_threads for each thread in the
515 * group with ->mm != NULL.
517 down_read(&mm
->mmap_sem
);
518 core_state
= mm
->core_state
;
520 struct core_thread self
;
522 up_read(&mm
->mmap_sem
);
525 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
527 * Implies mb(), the result of xchg() must be visible
528 * to core_state->dumper.
530 if (atomic_dec_and_test(&core_state
->nr_threads
))
531 complete(&core_state
->startup
);
534 set_current_state(TASK_UNINTERRUPTIBLE
);
535 if (!self
.task
) /* see coredump_finish() */
537 freezable_schedule();
539 __set_current_state(TASK_RUNNING
);
540 down_read(&mm
->mmap_sem
);
542 atomic_inc(&mm
->mm_count
);
543 BUG_ON(mm
!= current
->active_mm
);
544 /* more a memory barrier than a real lock */
547 up_read(&mm
->mmap_sem
);
548 enter_lazy_tlb(mm
, current
);
549 task_unlock(current
);
550 mm_update_next_owner(mm
);
551 userfaultfd_exit(mm
);
553 if (test_thread_flag(TIF_MEMDIE
))
557 static struct task_struct
*find_alive_thread(struct task_struct
*p
)
559 struct task_struct
*t
;
561 for_each_thread(p
, t
) {
562 if (!(t
->flags
& PF_EXITING
))
568 static struct task_struct
*find_child_reaper(struct task_struct
*father
)
569 __releases(&tasklist_lock
)
570 __acquires(&tasklist_lock
)
572 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
573 struct task_struct
*reaper
= pid_ns
->child_reaper
;
575 if (likely(reaper
!= father
))
578 reaper
= find_alive_thread(father
);
580 pid_ns
->child_reaper
= reaper
;
584 write_unlock_irq(&tasklist_lock
);
585 if (unlikely(pid_ns
== &init_pid_ns
)) {
586 panic("Attempted to kill init! exitcode=0x%08x\n",
587 father
->signal
->group_exit_code
?: father
->exit_code
);
589 zap_pid_ns_processes(pid_ns
);
590 write_lock_irq(&tasklist_lock
);
596 * When we die, we re-parent all our children, and try to:
597 * 1. give them to another thread in our thread group, if such a member exists
598 * 2. give it to the first ancestor process which prctl'd itself as a
599 * child_subreaper for its children (like a service manager)
600 * 3. give it to the init process (PID 1) in our pid namespace
602 static struct task_struct
*find_new_reaper(struct task_struct
*father
,
603 struct task_struct
*child_reaper
)
605 struct task_struct
*thread
, *reaper
;
607 thread
= find_alive_thread(father
);
611 if (father
->signal
->has_child_subreaper
) {
612 unsigned int ns_level
= task_pid(father
)->level
;
614 * Find the first ->is_child_subreaper ancestor in our pid_ns.
615 * We can't check reaper != child_reaper to ensure we do not
616 * cross the namespaces, the exiting parent could be injected
617 * by setns() + fork().
618 * We check pid->level, this is slightly more efficient than
619 * task_active_pid_ns(reaper) != task_active_pid_ns(father).
621 for (reaper
= father
->real_parent
;
622 task_pid(reaper
)->level
== ns_level
;
623 reaper
= reaper
->real_parent
) {
624 if (reaper
== &init_task
)
626 if (!reaper
->signal
->is_child_subreaper
)
628 thread
= find_alive_thread(reaper
);
638 * Any that need to be release_task'd are put on the @dead list.
640 static void reparent_leader(struct task_struct
*father
, struct task_struct
*p
,
641 struct list_head
*dead
)
643 if (unlikely(p
->exit_state
== EXIT_DEAD
))
646 /* We don't want people slaying init. */
647 p
->exit_signal
= SIGCHLD
;
649 /* If it has exited notify the new parent about this child's death. */
651 p
->exit_state
== EXIT_ZOMBIE
&& thread_group_empty(p
)) {
652 if (do_notify_parent(p
, p
->exit_signal
)) {
653 p
->exit_state
= EXIT_DEAD
;
654 list_add(&p
->ptrace_entry
, dead
);
658 kill_orphaned_pgrp(p
, father
);
662 * This does two things:
664 * A. Make init inherit all the child processes
665 * B. Check to see if any process groups have become orphaned
666 * as a result of our exiting, and if they have any stopped
667 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
669 static void forget_original_parent(struct task_struct
*father
,
670 struct list_head
*dead
)
672 struct task_struct
*p
, *t
, *reaper
;
674 if (unlikely(!list_empty(&father
->ptraced
)))
675 exit_ptrace(father
, dead
);
677 /* Can drop and reacquire tasklist_lock */
678 reaper
= find_child_reaper(father
);
679 if (list_empty(&father
->children
))
682 reaper
= find_new_reaper(father
, reaper
);
683 list_for_each_entry(p
, &father
->children
, sibling
) {
684 for_each_thread(p
, t
) {
685 t
->real_parent
= reaper
;
686 BUG_ON((!t
->ptrace
) != (t
->parent
== father
));
687 if (likely(!t
->ptrace
))
688 t
->parent
= t
->real_parent
;
689 if (t
->pdeath_signal
)
690 group_send_sig_info(t
->pdeath_signal
,
694 * If this is a threaded reparent there is no need to
695 * notify anyone anything has happened.
697 if (!same_thread_group(reaper
, father
))
698 reparent_leader(father
, p
, dead
);
700 list_splice_tail_init(&father
->children
, &reaper
->children
);
704 * Send signals to all our closest relatives so that they know
705 * to properly mourn us..
707 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
710 struct task_struct
*p
, *n
;
713 write_lock_irq(&tasklist_lock
);
714 forget_original_parent(tsk
, &dead
);
717 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
719 if (unlikely(tsk
->ptrace
)) {
720 int sig
= thread_group_leader(tsk
) &&
721 thread_group_empty(tsk
) &&
722 !ptrace_reparented(tsk
) ?
723 tsk
->exit_signal
: SIGCHLD
;
724 autoreap
= do_notify_parent(tsk
, sig
);
725 } else if (thread_group_leader(tsk
)) {
726 autoreap
= thread_group_empty(tsk
) &&
727 do_notify_parent(tsk
, tsk
->exit_signal
);
732 tsk
->exit_state
= autoreap
? EXIT_DEAD
: EXIT_ZOMBIE
;
733 if (tsk
->exit_state
== EXIT_DEAD
)
734 list_add(&tsk
->ptrace_entry
, &dead
);
736 /* mt-exec, de_thread() is waiting for group leader */
737 if (unlikely(tsk
->signal
->notify_count
< 0))
738 wake_up_process(tsk
->signal
->group_exit_task
);
739 write_unlock_irq(&tasklist_lock
);
741 list_for_each_entry_safe(p
, n
, &dead
, ptrace_entry
) {
742 list_del_init(&p
->ptrace_entry
);
747 #ifdef CONFIG_DEBUG_STACK_USAGE
748 static void check_stack_usage(void)
750 static DEFINE_SPINLOCK(low_water_lock
);
751 static int lowest_to_date
= THREAD_SIZE
;
754 free
= stack_not_used(current
);
756 if (free
>= lowest_to_date
)
759 spin_lock(&low_water_lock
);
760 if (free
< lowest_to_date
) {
761 pr_info("%s (%d) used greatest stack depth: %lu bytes left\n",
762 current
->comm
, task_pid_nr(current
), free
);
763 lowest_to_date
= free
;
765 spin_unlock(&low_water_lock
);
768 static inline void check_stack_usage(void) {}
771 void __noreturn
do_exit(long code
)
773 struct task_struct
*tsk
= current
;
775 TASKS_RCU(int tasks_rcu_i
);
777 profile_task_exit(tsk
);
780 WARN_ON(blk_needs_flush_plug(tsk
));
782 if (unlikely(in_interrupt()))
783 panic("Aiee, killing interrupt handler!");
784 if (unlikely(!tsk
->pid
))
785 panic("Attempted to kill the idle task!");
788 * If do_exit is called because this processes oopsed, it's possible
789 * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before
790 * continuing. Amongst other possible reasons, this is to prevent
791 * mm_release()->clear_child_tid() from writing to a user-controlled
796 ptrace_event(PTRACE_EVENT_EXIT
, code
);
798 validate_creds_for_do_exit(tsk
);
801 * We're taking recursive faults here in do_exit. Safest is to just
802 * leave this task alone and wait for reboot.
804 if (unlikely(tsk
->flags
& PF_EXITING
)) {
805 pr_alert("Fixing recursive fault but reboot is needed!\n");
807 * We can do this unlocked here. The futex code uses
808 * this flag just to verify whether the pi state
809 * cleanup has been done or not. In the worst case it
810 * loops once more. We pretend that the cleanup was
811 * done as there is no way to return. Either the
812 * OWNER_DIED bit is set by now or we push the blocked
813 * task into the wait for ever nirwana as well.
815 tsk
->flags
|= PF_EXITPIDONE
;
816 set_current_state(TASK_UNINTERRUPTIBLE
);
820 exit_signals(tsk
); /* sets PF_EXITING */
822 * Ensure that all new tsk->pi_lock acquisitions must observe
823 * PF_EXITING. Serializes against futex.c:attach_to_pi_owner().
827 * Ensure that we must observe the pi_state in exit_mm() ->
828 * mm_release() -> exit_pi_state_list().
830 raw_spin_unlock_wait(&tsk
->pi_lock
);
832 if (unlikely(in_atomic())) {
833 pr_info("note: %s[%d] exited with preempt_count %d\n",
834 current
->comm
, task_pid_nr(current
),
836 preempt_count_set(PREEMPT_ENABLED
);
839 /* sync mm's RSS info before statistics gathering */
841 sync_mm_rss(tsk
->mm
);
842 acct_update_integrals(tsk
);
843 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
845 #ifdef CONFIG_POSIX_TIMERS
846 hrtimer_cancel(&tsk
->signal
->real_timer
);
847 exit_itimers(tsk
->signal
);
850 setmax_mm_hiwater_rss(&tsk
->signal
->maxrss
, tsk
->mm
);
852 acct_collect(code
, group_dead
);
857 tsk
->exit_code
= code
;
858 taskstats_exit(tsk
, group_dead
);
864 trace_sched_process_exit(tsk
);
871 disassociate_ctty(1);
872 exit_task_namespaces(tsk
);
877 * Flush inherited counters to the parent - before the parent
878 * gets woken up by child-exit notifications.
880 * because of cgroup mode, must be called before cgroup_exit()
882 perf_event_exit_task(tsk
);
884 sched_autogroup_exit_task(tsk
);
888 * FIXME: do that only when needed, using sched_exit tracepoint
890 flush_ptrace_hw_breakpoint(tsk
);
892 TASKS_RCU(preempt_disable());
893 TASKS_RCU(tasks_rcu_i
= __srcu_read_lock(&tasks_rcu_exit_srcu
));
894 TASKS_RCU(preempt_enable());
895 exit_notify(tsk
, group_dead
);
896 proc_exit_connector(tsk
);
897 mpol_put_task_policy(tsk
);
899 if (unlikely(current
->pi_state_cache
))
900 kfree(current
->pi_state_cache
);
903 * Make sure we are holding no locks:
905 debug_check_no_locks_held();
907 * We can do this unlocked here. The futex code uses this flag
908 * just to verify whether the pi state cleanup has been done
909 * or not. In the worst case it loops once more.
911 tsk
->flags
|= PF_EXITPIDONE
;
914 exit_io_context(tsk
);
916 if (tsk
->splice_pipe
)
917 free_pipe_info(tsk
->splice_pipe
);
919 if (tsk
->task_frag
.page
)
920 put_page(tsk
->task_frag
.page
);
922 validate_creds_for_do_exit(tsk
);
927 __this_cpu_add(dirty_throttle_leaks
, tsk
->nr_dirtied
);
929 TASKS_RCU(__srcu_read_unlock(&tasks_rcu_exit_srcu
, tasks_rcu_i
));
933 EXPORT_SYMBOL_GPL(do_exit
);
935 void complete_and_exit(struct completion
*comp
, long code
)
942 EXPORT_SYMBOL(complete_and_exit
);
944 SYSCALL_DEFINE1(exit
, int, error_code
)
946 do_exit((error_code
&0xff)<<8);
950 * Take down every thread in the group. This is called by fatal signals
951 * as well as by sys_exit_group (below).
954 do_group_exit(int exit_code
)
956 struct signal_struct
*sig
= current
->signal
;
958 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
960 if (signal_group_exit(sig
))
961 exit_code
= sig
->group_exit_code
;
962 else if (!thread_group_empty(current
)) {
963 struct sighand_struct
*const sighand
= current
->sighand
;
965 spin_lock_irq(&sighand
->siglock
);
966 if (signal_group_exit(sig
))
967 /* Another thread got here before we took the lock. */
968 exit_code
= sig
->group_exit_code
;
970 sig
->group_exit_code
= exit_code
;
971 sig
->flags
= SIGNAL_GROUP_EXIT
;
972 zap_other_threads(current
);
974 spin_unlock_irq(&sighand
->siglock
);
982 * this kills every thread in the thread group. Note that any externally
983 * wait4()-ing process will get the correct exit code - even if this
984 * thread is not the thread group leader.
986 SYSCALL_DEFINE1(exit_group
, int, error_code
)
988 do_group_exit((error_code
& 0xff) << 8);
994 enum pid_type wo_type
;
998 struct siginfo __user
*wo_info
;
1000 struct rusage __user
*wo_rusage
;
1002 wait_queue_t child_wait
;
1007 struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1009 if (type
!= PIDTYPE_PID
)
1010 task
= task
->group_leader
;
1011 return task
->pids
[type
].pid
;
1014 static int eligible_pid(struct wait_opts
*wo
, struct task_struct
*p
)
1016 return wo
->wo_type
== PIDTYPE_MAX
||
1017 task_pid_type(p
, wo
->wo_type
) == wo
->wo_pid
;
1021 eligible_child(struct wait_opts
*wo
, bool ptrace
, struct task_struct
*p
)
1023 if (!eligible_pid(wo
, p
))
1027 * Wait for all children (clone and not) if __WALL is set or
1028 * if it is traced by us.
1030 if (ptrace
|| (wo
->wo_flags
& __WALL
))
1034 * Otherwise, wait for clone children *only* if __WCLONE is set;
1035 * otherwise, wait for non-clone children *only*.
1037 * Note: a "clone" child here is one that reports to its parent
1038 * using a signal other than SIGCHLD, or a non-leader thread which
1039 * we can only see if it is traced by us.
1041 if ((p
->exit_signal
!= SIGCHLD
) ^ !!(wo
->wo_flags
& __WCLONE
))
1047 static int wait_noreap_copyout(struct wait_opts
*wo
, struct task_struct
*p
,
1048 pid_t pid
, uid_t uid
, int why
, int status
)
1050 struct siginfo __user
*infop
;
1051 int retval
= wo
->wo_rusage
1052 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1055 infop
= wo
->wo_info
;
1058 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1060 retval
= put_user(0, &infop
->si_errno
);
1062 retval
= put_user((short)why
, &infop
->si_code
);
1064 retval
= put_user(pid
, &infop
->si_pid
);
1066 retval
= put_user(uid
, &infop
->si_uid
);
1068 retval
= put_user(status
, &infop
->si_status
);
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
)
1083 int state
, retval
, status
;
1084 pid_t pid
= task_pid_vnr(p
);
1085 uid_t uid
= from_kuid_munged(current_user_ns(), task_uid(p
));
1086 struct siginfo __user
*infop
;
1088 if (!likely(wo
->wo_flags
& WEXITED
))
1091 if (unlikely(wo
->wo_flags
& WNOWAIT
)) {
1092 int exit_code
= p
->exit_code
;
1096 read_unlock(&tasklist_lock
);
1097 sched_annotate_sleep();
1099 if ((exit_code
& 0x7f) == 0) {
1101 status
= exit_code
>> 8;
1103 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1104 status
= exit_code
& 0x7f;
1106 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, status
);
1109 * Move the task's state to DEAD/TRACE, only one thread can do this.
1111 state
= (ptrace_reparented(p
) && thread_group_leader(p
)) ?
1112 EXIT_TRACE
: EXIT_DEAD
;
1113 if (cmpxchg(&p
->exit_state
, EXIT_ZOMBIE
, state
) != EXIT_ZOMBIE
)
1116 * We own this thread, nobody else can reap it.
1118 read_unlock(&tasklist_lock
);
1119 sched_annotate_sleep();
1122 * Check thread_group_leader() to exclude the traced sub-threads.
1124 if (state
== EXIT_DEAD
&& thread_group_leader(p
)) {
1125 struct signal_struct
*sig
= p
->signal
;
1126 struct signal_struct
*psig
= current
->signal
;
1127 unsigned long maxrss
;
1128 u64 tgutime
, tgstime
;
1131 * The resource counters for the group leader are in its
1132 * own task_struct. Those for dead threads in the group
1133 * are in its signal_struct, as are those for the child
1134 * processes it has previously reaped. All these
1135 * accumulate in the parent's signal_struct c* fields.
1137 * We don't bother to take a lock here to protect these
1138 * p->signal fields because the whole thread group is dead
1139 * and nobody can change them.
1141 * psig->stats_lock also protects us from our sub-theads
1142 * which can reap other children at the same time. Until
1143 * we change k_getrusage()-like users to rely on this lock
1144 * we have to take ->siglock as well.
1146 * We use thread_group_cputime_adjusted() to get times for
1147 * the thread group, which consolidates times for all threads
1148 * in the group including the group leader.
1150 thread_group_cputime_adjusted(p
, &tgutime
, &tgstime
);
1151 spin_lock_irq(¤t
->sighand
->siglock
);
1152 write_seqlock(&psig
->stats_lock
);
1153 psig
->cutime
+= tgutime
+ sig
->cutime
;
1154 psig
->cstime
+= tgstime
+ sig
->cstime
;
1155 psig
->cgtime
+= task_gtime(p
) + sig
->gtime
+ sig
->cgtime
;
1157 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1159 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1161 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1163 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1165 task_io_get_inblock(p
) +
1166 sig
->inblock
+ sig
->cinblock
;
1168 task_io_get_oublock(p
) +
1169 sig
->oublock
+ sig
->coublock
;
1170 maxrss
= max(sig
->maxrss
, sig
->cmaxrss
);
1171 if (psig
->cmaxrss
< maxrss
)
1172 psig
->cmaxrss
= maxrss
;
1173 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1174 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1175 write_sequnlock(&psig
->stats_lock
);
1176 spin_unlock_irq(¤t
->sighand
->siglock
);
1179 retval
= wo
->wo_rusage
1180 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1181 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1182 ? p
->signal
->group_exit_code
: p
->exit_code
;
1183 if (!retval
&& wo
->wo_stat
)
1184 retval
= put_user(status
, wo
->wo_stat
);
1186 infop
= wo
->wo_info
;
1187 if (!retval
&& infop
)
1188 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1189 if (!retval
&& infop
)
1190 retval
= put_user(0, &infop
->si_errno
);
1191 if (!retval
&& infop
) {
1194 if ((status
& 0x7f) == 0) {
1198 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1201 retval
= put_user((short)why
, &infop
->si_code
);
1203 retval
= put_user(status
, &infop
->si_status
);
1205 if (!retval
&& infop
)
1206 retval
= put_user(pid
, &infop
->si_pid
);
1207 if (!retval
&& infop
)
1208 retval
= put_user(uid
, &infop
->si_uid
);
1212 if (state
== EXIT_TRACE
) {
1213 write_lock_irq(&tasklist_lock
);
1214 /* We dropped tasklist, ptracer could die and untrace */
1217 /* If parent wants a zombie, don't release it now */
1218 state
= EXIT_ZOMBIE
;
1219 if (do_notify_parent(p
, p
->exit_signal
))
1221 p
->exit_state
= state
;
1222 write_unlock_irq(&tasklist_lock
);
1224 if (state
== EXIT_DEAD
)
1230 static int *task_stopped_code(struct task_struct
*p
, bool ptrace
)
1233 if (task_is_traced(p
) && !(p
->jobctl
& JOBCTL_LISTENING
))
1234 return &p
->exit_code
;
1236 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
)
1237 return &p
->signal
->group_exit_code
;
1243 * wait_task_stopped - Wait for %TASK_STOPPED or %TASK_TRACED
1245 * @ptrace: is the wait for ptrace
1246 * @p: task to wait for
1248 * Handle sys_wait4() work for %p in state %TASK_STOPPED or %TASK_TRACED.
1251 * read_lock(&tasklist_lock), which is released if return value is
1252 * non-zero. Also, grabs and releases @p->sighand->siglock.
1255 * 0 if wait condition didn't exist and search for other wait conditions
1256 * should continue. Non-zero return, -errno on failure and @p's pid on
1257 * success, implies that tasklist_lock is released and wait condition
1258 * search should terminate.
1260 static int wait_task_stopped(struct wait_opts
*wo
,
1261 int ptrace
, struct task_struct
*p
)
1263 struct siginfo __user
*infop
;
1264 int retval
, exit_code
, *p_code
, why
;
1265 uid_t uid
= 0; /* unneeded, required by compiler */
1269 * Traditionally we see ptrace'd stopped tasks regardless of options.
1271 if (!ptrace
&& !(wo
->wo_flags
& WUNTRACED
))
1274 if (!task_stopped_code(p
, ptrace
))
1278 spin_lock_irq(&p
->sighand
->siglock
);
1280 p_code
= task_stopped_code(p
, ptrace
);
1281 if (unlikely(!p_code
))
1284 exit_code
= *p_code
;
1288 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1291 uid
= from_kuid_munged(current_user_ns(), task_uid(p
));
1293 spin_unlock_irq(&p
->sighand
->siglock
);
1298 * Now we are pretty sure this task is interesting.
1299 * Make sure it doesn't get reaped out from under us while we
1300 * give up the lock and then examine it below. We don't want to
1301 * keep holding onto the tasklist_lock while we call getrusage and
1302 * possibly take page faults for user memory.
1305 pid
= task_pid_vnr(p
);
1306 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1307 read_unlock(&tasklist_lock
);
1308 sched_annotate_sleep();
1310 if (unlikely(wo
->wo_flags
& WNOWAIT
))
1311 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, exit_code
);
1313 retval
= wo
->wo_rusage
1314 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1315 if (!retval
&& wo
->wo_stat
)
1316 retval
= put_user((exit_code
<< 8) | 0x7f, wo
->wo_stat
);
1318 infop
= wo
->wo_info
;
1319 if (!retval
&& infop
)
1320 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1321 if (!retval
&& infop
)
1322 retval
= put_user(0, &infop
->si_errno
);
1323 if (!retval
&& infop
)
1324 retval
= put_user((short)why
, &infop
->si_code
);
1325 if (!retval
&& infop
)
1326 retval
= put_user(exit_code
, &infop
->si_status
);
1327 if (!retval
&& infop
)
1328 retval
= put_user(pid
, &infop
->si_pid
);
1329 if (!retval
&& infop
)
1330 retval
= put_user(uid
, &infop
->si_uid
);
1340 * Handle do_wait work for one task in a live, non-stopped state.
1341 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1342 * the lock and this task is uninteresting. If we return nonzero, we have
1343 * released the lock and the system call should return.
1345 static int wait_task_continued(struct wait_opts
*wo
, struct task_struct
*p
)
1351 if (!unlikely(wo
->wo_flags
& WCONTINUED
))
1354 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1357 spin_lock_irq(&p
->sighand
->siglock
);
1358 /* Re-check with the lock held. */
1359 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1360 spin_unlock_irq(&p
->sighand
->siglock
);
1363 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1364 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1365 uid
= from_kuid_munged(current_user_ns(), task_uid(p
));
1366 spin_unlock_irq(&p
->sighand
->siglock
);
1368 pid
= task_pid_vnr(p
);
1370 read_unlock(&tasklist_lock
);
1371 sched_annotate_sleep();
1374 retval
= wo
->wo_rusage
1375 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1377 if (!retval
&& wo
->wo_stat
)
1378 retval
= put_user(0xffff, wo
->wo_stat
);
1382 retval
= wait_noreap_copyout(wo
, p
, pid
, uid
,
1383 CLD_CONTINUED
, SIGCONT
);
1384 BUG_ON(retval
== 0);
1391 * Consider @p for a wait by @parent.
1393 * -ECHILD should be in ->notask_error before the first call.
1394 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1395 * Returns zero if the search for a child should continue;
1396 * then ->notask_error is 0 if @p is an eligible child,
1399 static int wait_consider_task(struct wait_opts
*wo
, int ptrace
,
1400 struct task_struct
*p
)
1403 * We can race with wait_task_zombie() from another thread.
1404 * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
1405 * can't confuse the checks below.
1407 int exit_state
= ACCESS_ONCE(p
->exit_state
);
1410 if (unlikely(exit_state
== EXIT_DEAD
))
1413 ret
= eligible_child(wo
, ptrace
, p
);
1417 if (unlikely(exit_state
== EXIT_TRACE
)) {
1419 * ptrace == 0 means we are the natural parent. In this case
1420 * we should clear notask_error, debugger will notify us.
1422 if (likely(!ptrace
))
1423 wo
->notask_error
= 0;
1427 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1429 * If it is traced by its real parent's group, just pretend
1430 * the caller is ptrace_do_wait() and reap this child if it
1433 * This also hides group stop state from real parent; otherwise
1434 * a single stop can be reported twice as group and ptrace stop.
1435 * If a ptracer wants to distinguish these two events for its
1436 * own children it should create a separate process which takes
1437 * the role of real parent.
1439 if (!ptrace_reparented(p
))
1444 if (exit_state
== EXIT_ZOMBIE
) {
1445 /* we don't reap group leaders with subthreads */
1446 if (!delay_group_leader(p
)) {
1448 * A zombie ptracee is only visible to its ptracer.
1449 * Notification and reaping will be cascaded to the
1450 * real parent when the ptracer detaches.
1452 if (unlikely(ptrace
) || likely(!p
->ptrace
))
1453 return wait_task_zombie(wo
, p
);
1457 * Allow access to stopped/continued state via zombie by
1458 * falling through. Clearing of notask_error is complex.
1462 * If WEXITED is set, notask_error should naturally be
1463 * cleared. If not, subset of WSTOPPED|WCONTINUED is set,
1464 * so, if there are live subthreads, there are events to
1465 * wait for. If all subthreads are dead, it's still safe
1466 * to clear - this function will be called again in finite
1467 * amount time once all the subthreads are released and
1468 * will then return without clearing.
1472 * Stopped state is per-task and thus can't change once the
1473 * target task dies. Only continued and exited can happen.
1474 * Clear notask_error if WCONTINUED | WEXITED.
1476 if (likely(!ptrace
) || (wo
->wo_flags
& (WCONTINUED
| WEXITED
)))
1477 wo
->notask_error
= 0;
1480 * @p is alive and it's gonna stop, continue or exit, so
1481 * there always is something to wait for.
1483 wo
->notask_error
= 0;
1487 * Wait for stopped. Depending on @ptrace, different stopped state
1488 * is used and the two don't interact with each other.
1490 ret
= wait_task_stopped(wo
, ptrace
, p
);
1495 * Wait for continued. There's only one continued state and the
1496 * ptracer can consume it which can confuse the real parent. Don't
1497 * use WCONTINUED from ptracer. You don't need or want it.
1499 return wait_task_continued(wo
, p
);
1503 * Do the work of do_wait() for one thread in the group, @tsk.
1505 * -ECHILD should be in ->notask_error before the first call.
1506 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1507 * Returns zero if the search for a child should continue; then
1508 * ->notask_error is 0 if there were any eligible children,
1511 static int do_wait_thread(struct wait_opts
*wo
, struct task_struct
*tsk
)
1513 struct task_struct
*p
;
1515 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1516 int ret
= wait_consider_task(wo
, 0, p
);
1525 static int ptrace_do_wait(struct wait_opts
*wo
, struct task_struct
*tsk
)
1527 struct task_struct
*p
;
1529 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1530 int ret
= wait_consider_task(wo
, 1, p
);
1539 static int child_wait_callback(wait_queue_t
*wait
, unsigned mode
,
1540 int sync
, void *key
)
1542 struct wait_opts
*wo
= container_of(wait
, struct wait_opts
,
1544 struct task_struct
*p
= key
;
1546 if (!eligible_pid(wo
, p
))
1549 if ((wo
->wo_flags
& __WNOTHREAD
) && wait
->private != p
->parent
)
1552 return default_wake_function(wait
, mode
, sync
, key
);
1555 void __wake_up_parent(struct task_struct
*p
, struct task_struct
*parent
)
1557 __wake_up_sync_key(&parent
->signal
->wait_chldexit
,
1558 TASK_INTERRUPTIBLE
, 1, p
);
1561 static long do_wait(struct wait_opts
*wo
)
1563 struct task_struct
*tsk
;
1566 trace_sched_process_wait(wo
->wo_pid
);
1568 init_waitqueue_func_entry(&wo
->child_wait
, child_wait_callback
);
1569 wo
->child_wait
.private = current
;
1570 add_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1573 * If there is nothing that can match our criteria, just get out.
1574 * We will clear ->notask_error to zero if we see any child that
1575 * might later match our criteria, even if we are not able to reap
1578 wo
->notask_error
= -ECHILD
;
1579 if ((wo
->wo_type
< PIDTYPE_MAX
) &&
1580 (!wo
->wo_pid
|| hlist_empty(&wo
->wo_pid
->tasks
[wo
->wo_type
])))
1583 set_current_state(TASK_INTERRUPTIBLE
);
1584 read_lock(&tasklist_lock
);
1587 retval
= do_wait_thread(wo
, tsk
);
1591 retval
= ptrace_do_wait(wo
, tsk
);
1595 if (wo
->wo_flags
& __WNOTHREAD
)
1597 } while_each_thread(current
, tsk
);
1598 read_unlock(&tasklist_lock
);
1601 retval
= wo
->notask_error
;
1602 if (!retval
&& !(wo
->wo_flags
& WNOHANG
)) {
1603 retval
= -ERESTARTSYS
;
1604 if (!signal_pending(current
)) {
1610 __set_current_state(TASK_RUNNING
);
1611 remove_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1615 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1616 infop
, int, options
, struct rusage __user
*, ru
)
1618 struct wait_opts wo
;
1619 struct pid
*pid
= NULL
;
1623 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
|
1624 __WNOTHREAD
|__WCLONE
|__WALL
))
1626 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1639 type
= PIDTYPE_PGID
;
1647 if (type
< PIDTYPE_MAX
)
1648 pid
= find_get_pid(upid
);
1652 wo
.wo_flags
= options
;
1662 * For a WNOHANG return, clear out all the fields
1663 * we would set so the user can easily tell the
1667 ret
= put_user(0, &infop
->si_signo
);
1669 ret
= put_user(0, &infop
->si_errno
);
1671 ret
= put_user(0, &infop
->si_code
);
1673 ret
= put_user(0, &infop
->si_pid
);
1675 ret
= put_user(0, &infop
->si_uid
);
1677 ret
= put_user(0, &infop
->si_status
);
1684 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1685 int, options
, struct rusage __user
*, ru
)
1687 struct wait_opts wo
;
1688 struct pid
*pid
= NULL
;
1692 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1693 __WNOTHREAD
|__WCLONE
|__WALL
))
1698 else if (upid
< 0) {
1699 type
= PIDTYPE_PGID
;
1700 pid
= find_get_pid(-upid
);
1701 } else if (upid
== 0) {
1702 type
= PIDTYPE_PGID
;
1703 pid
= get_task_pid(current
, PIDTYPE_PGID
);
1704 } else /* upid > 0 */ {
1706 pid
= find_get_pid(upid
);
1711 wo
.wo_flags
= options
| WEXITED
;
1713 wo
.wo_stat
= stat_addr
;
1721 #ifdef __ARCH_WANT_SYS_WAITPID
1724 * sys_waitpid() remains for compatibility. waitpid() should be
1725 * implemented by calling sys_wait4() from libc.a.
1727 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1729 return sys_wait4(pid
, stat_addr
, options
, NULL
);