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/security.h>
18 #include <linux/cpu.h>
19 #include <linux/acct.h>
20 #include <linux/tsacct_kern.h>
21 #include <linux/file.h>
22 #include <linux/fdtable.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/freezer.h>
35 #include <linux/cgroup.h>
36 #include <linux/syscalls.h>
37 #include <linux/signal.h>
38 #include <linux/posix-timers.h>
39 #include <linux/cn_proc.h>
40 #include <linux/mutex.h>
41 #include <linux/futex.h>
42 #include <linux/pipe_fs_i.h>
43 #include <linux/audit.h> /* for audit_free() */
44 #include <linux/resource.h>
45 #include <linux/blkdev.h>
46 #include <linux/task_io_accounting_ops.h>
47 #include <linux/tracehook.h>
48 #include <linux/fs_struct.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>
54 #include <asm/uaccess.h>
55 #include <asm/unistd.h>
56 #include <asm/pgtable.h>
57 #include <asm/mmu_context.h>
59 static void exit_mm(struct task_struct
* tsk
);
61 static void __unhash_process(struct task_struct
*p
)
64 detach_pid(p
, PIDTYPE_PID
);
65 if (thread_group_leader(p
)) {
66 detach_pid(p
, PIDTYPE_PGID
);
67 detach_pid(p
, PIDTYPE_SID
);
69 list_del_rcu(&p
->tasks
);
70 list_del_init(&p
->sibling
);
71 __get_cpu_var(process_counts
)--;
73 list_del_rcu(&p
->thread_group
);
77 * This function expects the tasklist_lock write-locked.
79 static void __exit_signal(struct task_struct
*tsk
)
81 struct signal_struct
*sig
= tsk
->signal
;
82 struct sighand_struct
*sighand
;
85 BUG_ON(!atomic_read(&sig
->count
));
87 sighand
= rcu_dereference_check(tsk
->sighand
,
88 rcu_read_lock_held() ||
89 lockdep_tasklist_lock_is_held());
90 spin_lock(&sighand
->siglock
);
91 atomic_dec(&sig
->count
);
93 posix_cpu_timers_exit(tsk
);
94 if (thread_group_leader(tsk
)) {
95 posix_cpu_timers_exit_group(tsk
);
98 * If there is any task waiting for the group exit
101 if (sig
->notify_count
> 0 && !--sig
->notify_count
)
102 wake_up_process(sig
->group_exit_task
);
104 if (tsk
== sig
->curr_target
)
105 sig
->curr_target
= next_thread(tsk
);
107 * Accumulate here the counters for all threads but the
108 * group leader as they die, so they can be added into
109 * the process-wide totals when those are taken.
110 * The group leader stays around as a zombie as long
111 * as there are other threads. When it gets reaped,
112 * the exit.c code will add its counts into these totals.
113 * We won't ever get here for the group leader, since it
114 * will have been the last reference on the signal_struct.
116 sig
->utime
= cputime_add(sig
->utime
, tsk
->utime
);
117 sig
->stime
= cputime_add(sig
->stime
, tsk
->stime
);
118 sig
->gtime
= cputime_add(sig
->gtime
, tsk
->gtime
);
119 sig
->min_flt
+= tsk
->min_flt
;
120 sig
->maj_flt
+= tsk
->maj_flt
;
121 sig
->nvcsw
+= tsk
->nvcsw
;
122 sig
->nivcsw
+= tsk
->nivcsw
;
123 sig
->inblock
+= task_io_get_inblock(tsk
);
124 sig
->oublock
+= task_io_get_oublock(tsk
);
125 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
126 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
127 sig
= NULL
; /* Marker for below. */
130 __unhash_process(tsk
);
133 * Do this under ->siglock, we can race with another thread
134 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
136 flush_sigqueue(&tsk
->pending
);
140 spin_unlock(&sighand
->siglock
);
142 __cleanup_sighand(sighand
);
143 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
145 flush_sigqueue(&sig
->shared_pending
);
146 taskstats_tgid_free(sig
);
148 * Make sure ->signal can't go away under rq->lock,
149 * see account_group_exec_runtime().
151 task_rq_unlock_wait(tsk
);
152 tty_kref_put(sig
->tty
);
153 __cleanup_signal(sig
);
157 static void delayed_put_task_struct(struct rcu_head
*rhp
)
159 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
161 #ifdef CONFIG_PERF_EVENTS
162 WARN_ON_ONCE(tsk
->perf_event_ctxp
);
164 trace_sched_process_free(tsk
);
165 put_task_struct(tsk
);
169 void release_task(struct task_struct
* p
)
171 struct task_struct
*leader
;
174 tracehook_prepare_release_task(p
);
175 /* don't need to get the RCU readlock here - the process is dead and
176 * can't be modifying its own credentials. But shut RCU-lockdep up */
178 atomic_dec(&__task_cred(p
)->user
->processes
);
183 write_lock_irq(&tasklist_lock
);
184 tracehook_finish_release_task(p
);
188 * If we are the last non-leader member of the thread
189 * group, and the leader is zombie, then notify the
190 * group leader's parent process. (if it wants notification.)
193 leader
= p
->group_leader
;
194 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
195 BUG_ON(task_detached(leader
));
196 do_notify_parent(leader
, leader
->exit_signal
);
198 * If we were the last child thread and the leader has
199 * exited already, and the leader's parent ignores SIGCHLD,
200 * then we are the one who should release the leader.
202 * do_notify_parent() will have marked it self-reaping in
205 zap_leader
= task_detached(leader
);
208 * This maintains the invariant that release_task()
209 * only runs on a task in EXIT_DEAD, just for sanity.
212 leader
->exit_state
= EXIT_DEAD
;
215 write_unlock_irq(&tasklist_lock
);
217 call_rcu(&p
->rcu
, delayed_put_task_struct
);
220 if (unlikely(zap_leader
))
225 * This checks not only the pgrp, but falls back on the pid if no
226 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
229 * The caller must hold rcu lock or the tasklist lock.
231 struct pid
*session_of_pgrp(struct pid
*pgrp
)
233 struct task_struct
*p
;
234 struct pid
*sid
= NULL
;
236 p
= pid_task(pgrp
, PIDTYPE_PGID
);
238 p
= pid_task(pgrp
, PIDTYPE_PID
);
240 sid
= task_session(p
);
246 * Determine if a process group is "orphaned", according to the POSIX
247 * definition in 2.2.2.52. Orphaned process groups are not to be affected
248 * by terminal-generated stop signals. Newly orphaned process groups are
249 * to receive a SIGHUP and a SIGCONT.
251 * "I ask you, have you ever known what it is to be an orphan?"
253 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
255 struct task_struct
*p
;
257 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
258 if ((p
== ignored_task
) ||
259 (p
->exit_state
&& thread_group_empty(p
)) ||
260 is_global_init(p
->real_parent
))
263 if (task_pgrp(p
->real_parent
) != pgrp
&&
264 task_session(p
->real_parent
) == task_session(p
))
266 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
271 int is_current_pgrp_orphaned(void)
275 read_lock(&tasklist_lock
);
276 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
277 read_unlock(&tasklist_lock
);
282 static int has_stopped_jobs(struct pid
*pgrp
)
285 struct task_struct
*p
;
287 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
288 if (!task_is_stopped(p
))
292 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
297 * Check to see if any process groups have become orphaned as
298 * a result of our exiting, and if they have any stopped jobs,
299 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
302 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
304 struct pid
*pgrp
= task_pgrp(tsk
);
305 struct task_struct
*ignored_task
= tsk
;
308 /* exit: our father is in a different pgrp than
309 * we are and we were the only connection outside.
311 parent
= tsk
->real_parent
;
313 /* reparent: our child is in a different pgrp than
314 * we are, and it was the only connection outside.
318 if (task_pgrp(parent
) != pgrp
&&
319 task_session(parent
) == task_session(tsk
) &&
320 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
321 has_stopped_jobs(pgrp
)) {
322 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
323 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
328 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
330 * If a kernel thread is launched as a result of a system call, or if
331 * it ever exits, it should generally reparent itself to kthreadd so it
332 * isn't in the way of other processes and is correctly cleaned up on exit.
334 * The various task state such as scheduling policy and priority may have
335 * been inherited from a user process, so we reset them to sane values here.
337 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
339 static void reparent_to_kthreadd(void)
341 write_lock_irq(&tasklist_lock
);
343 ptrace_unlink(current
);
344 /* Reparent to init */
345 current
->real_parent
= current
->parent
= kthreadd_task
;
346 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
348 /* Set the exit signal to SIGCHLD so we signal init on exit */
349 current
->exit_signal
= SIGCHLD
;
351 if (task_nice(current
) < 0)
352 set_user_nice(current
, 0);
356 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
357 sizeof(current
->signal
->rlim
));
359 atomic_inc(&init_cred
.usage
);
360 commit_creds(&init_cred
);
361 write_unlock_irq(&tasklist_lock
);
364 void __set_special_pids(struct pid
*pid
)
366 struct task_struct
*curr
= current
->group_leader
;
368 if (task_session(curr
) != pid
)
369 change_pid(curr
, PIDTYPE_SID
, pid
);
371 if (task_pgrp(curr
) != pid
)
372 change_pid(curr
, PIDTYPE_PGID
, pid
);
375 static void set_special_pids(struct pid
*pid
)
377 write_lock_irq(&tasklist_lock
);
378 __set_special_pids(pid
);
379 write_unlock_irq(&tasklist_lock
);
383 * Let kernel threads use this to say that they allow a certain signal.
384 * Must not be used if kthread was cloned with CLONE_SIGHAND.
386 int allow_signal(int sig
)
388 if (!valid_signal(sig
) || sig
< 1)
391 spin_lock_irq(¤t
->sighand
->siglock
);
392 /* This is only needed for daemonize()'ed kthreads */
393 sigdelset(¤t
->blocked
, sig
);
395 * Kernel threads handle their own signals. Let the signal code
396 * know it'll be handled, so that they don't get converted to
397 * SIGKILL or just silently dropped.
399 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
401 spin_unlock_irq(¤t
->sighand
->siglock
);
405 EXPORT_SYMBOL(allow_signal
);
407 int disallow_signal(int sig
)
409 if (!valid_signal(sig
) || sig
< 1)
412 spin_lock_irq(¤t
->sighand
->siglock
);
413 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
415 spin_unlock_irq(¤t
->sighand
->siglock
);
419 EXPORT_SYMBOL(disallow_signal
);
422 * Put all the gunge required to become a kernel thread without
423 * attached user resources in one place where it belongs.
426 void daemonize(const char *name
, ...)
431 va_start(args
, name
);
432 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
436 * If we were started as result of loading a module, close all of the
437 * user space pages. We don't need them, and if we didn't close them
438 * they would be locked into memory.
442 * We don't want to have TIF_FREEZE set if the system-wide hibernation
443 * or suspend transition begins right now.
445 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
447 if (current
->nsproxy
!= &init_nsproxy
) {
448 get_nsproxy(&init_nsproxy
);
449 switch_task_namespaces(current
, &init_nsproxy
);
451 set_special_pids(&init_struct_pid
);
452 proc_clear_tty(current
);
454 /* Block and flush all signals */
455 sigfillset(&blocked
);
456 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
457 flush_signals(current
);
459 /* Become as one with the init task */
461 daemonize_fs_struct();
463 current
->files
= init_task
.files
;
464 atomic_inc(¤t
->files
->count
);
466 reparent_to_kthreadd();
469 EXPORT_SYMBOL(daemonize
);
471 static void close_files(struct files_struct
* files
)
479 * It is safe to dereference the fd table without RCU or
480 * ->file_lock because this is the last reference to the
481 * files structure. But use RCU to shut RCU-lockdep up.
484 fdt
= files_fdtable(files
);
489 if (i
>= fdt
->max_fds
)
491 set
= fdt
->open_fds
->fds_bits
[j
++];
494 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
496 filp_close(file
, files
);
506 struct files_struct
*get_files_struct(struct task_struct
*task
)
508 struct files_struct
*files
;
513 atomic_inc(&files
->count
);
519 void put_files_struct(struct files_struct
*files
)
523 if (atomic_dec_and_test(&files
->count
)) {
526 * Free the fd and fdset arrays if we expanded them.
527 * If the fdtable was embedded, pass files for freeing
528 * at the end of the RCU grace period. Otherwise,
529 * you can free files immediately.
532 fdt
= files_fdtable(files
);
533 if (fdt
!= &files
->fdtab
)
534 kmem_cache_free(files_cachep
, files
);
540 void reset_files_struct(struct files_struct
*files
)
542 struct task_struct
*tsk
= current
;
543 struct files_struct
*old
;
549 put_files_struct(old
);
552 void exit_files(struct task_struct
*tsk
)
554 struct files_struct
* files
= tsk
->files
;
560 put_files_struct(files
);
564 #ifdef CONFIG_MM_OWNER
566 * Task p is exiting and it owned mm, lets find a new owner for it
569 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
572 * If there are other users of the mm and the owner (us) is exiting
573 * we need to find a new owner to take on the responsibility.
575 if (atomic_read(&mm
->mm_users
) <= 1)
582 void mm_update_next_owner(struct mm_struct
*mm
)
584 struct task_struct
*c
, *g
, *p
= current
;
587 if (!mm_need_new_owner(mm
, p
))
590 read_lock(&tasklist_lock
);
592 * Search in the children
594 list_for_each_entry(c
, &p
->children
, sibling
) {
596 goto assign_new_owner
;
600 * Search in the siblings
602 list_for_each_entry(c
, &p
->real_parent
->children
, sibling
) {
604 goto assign_new_owner
;
608 * Search through everything else. We should not get
611 do_each_thread(g
, c
) {
613 goto assign_new_owner
;
614 } while_each_thread(g
, c
);
616 read_unlock(&tasklist_lock
);
618 * We found no owner yet mm_users > 1: this implies that we are
619 * most likely racing with swapoff (try_to_unuse()) or /proc or
620 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
629 * The task_lock protects c->mm from changing.
630 * We always want mm->owner->mm == mm
634 * Delay read_unlock() till we have the task_lock()
635 * to ensure that c does not slip away underneath us
637 read_unlock(&tasklist_lock
);
647 #endif /* CONFIG_MM_OWNER */
650 * Turn us into a lazy TLB process if we
653 static void exit_mm(struct task_struct
* tsk
)
655 struct mm_struct
*mm
= tsk
->mm
;
656 struct core_state
*core_state
;
662 * Serialize with any possible pending coredump.
663 * We must hold mmap_sem around checking core_state
664 * and clearing tsk->mm. The core-inducing thread
665 * will increment ->nr_threads for each thread in the
666 * group with ->mm != NULL.
668 down_read(&mm
->mmap_sem
);
669 core_state
= mm
->core_state
;
671 struct core_thread self
;
672 up_read(&mm
->mmap_sem
);
675 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
677 * Implies mb(), the result of xchg() must be visible
678 * to core_state->dumper.
680 if (atomic_dec_and_test(&core_state
->nr_threads
))
681 complete(&core_state
->startup
);
684 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
685 if (!self
.task
) /* see coredump_finish() */
689 __set_task_state(tsk
, TASK_RUNNING
);
690 down_read(&mm
->mmap_sem
);
692 atomic_inc(&mm
->mm_count
);
693 BUG_ON(mm
!= tsk
->active_mm
);
694 /* more a memory barrier than a real lock */
697 up_read(&mm
->mmap_sem
);
698 enter_lazy_tlb(mm
, current
);
699 /* We don't want this task to be frozen prematurely */
700 clear_freeze_flag(tsk
);
702 mm_update_next_owner(mm
);
707 * When we die, we re-parent all our children.
708 * Try to give them to another thread in our thread
709 * group, and if no such member exists, give it to
710 * the child reaper process (ie "init") in our pid
713 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
715 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
716 struct task_struct
*thread
;
719 while_each_thread(father
, thread
) {
720 if (thread
->flags
& PF_EXITING
)
722 if (unlikely(pid_ns
->child_reaper
== father
))
723 pid_ns
->child_reaper
= thread
;
727 if (unlikely(pid_ns
->child_reaper
== father
)) {
728 write_unlock_irq(&tasklist_lock
);
729 if (unlikely(pid_ns
== &init_pid_ns
))
730 panic("Attempted to kill init!");
732 zap_pid_ns_processes(pid_ns
);
733 write_lock_irq(&tasklist_lock
);
735 * We can not clear ->child_reaper or leave it alone.
736 * There may by stealth EXIT_DEAD tasks on ->children,
737 * forget_original_parent() must move them somewhere.
739 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
742 return pid_ns
->child_reaper
;
746 * Any that need to be release_task'd are put on the @dead list.
748 static void reparent_leader(struct task_struct
*father
, struct task_struct
*p
,
749 struct list_head
*dead
)
751 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
753 if (task_detached(p
))
756 * If this is a threaded reparent there is no need to
757 * notify anyone anything has happened.
759 if (same_thread_group(p
->real_parent
, father
))
762 /* We don't want people slaying init. */
763 p
->exit_signal
= SIGCHLD
;
765 /* If it has exited notify the new parent about this child's death. */
766 if (!task_ptrace(p
) &&
767 p
->exit_state
== EXIT_ZOMBIE
&& thread_group_empty(p
)) {
768 do_notify_parent(p
, p
->exit_signal
);
769 if (task_detached(p
)) {
770 p
->exit_state
= EXIT_DEAD
;
771 list_move_tail(&p
->sibling
, dead
);
775 kill_orphaned_pgrp(p
, father
);
778 static void forget_original_parent(struct task_struct
*father
)
780 struct task_struct
*p
, *n
, *reaper
;
781 LIST_HEAD(dead_children
);
785 write_lock_irq(&tasklist_lock
);
786 reaper
= find_new_reaper(father
);
788 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
789 struct task_struct
*t
= p
;
791 t
->real_parent
= reaper
;
792 if (t
->parent
== father
) {
793 BUG_ON(task_ptrace(t
));
794 t
->parent
= t
->real_parent
;
796 if (t
->pdeath_signal
)
797 group_send_sig_info(t
->pdeath_signal
,
799 } while_each_thread(p
, t
);
800 reparent_leader(father
, p
, &dead_children
);
802 write_unlock_irq(&tasklist_lock
);
804 BUG_ON(!list_empty(&father
->children
));
806 list_for_each_entry_safe(p
, n
, &dead_children
, sibling
) {
807 list_del_init(&p
->sibling
);
813 * Send signals to all our closest relatives so that they know
814 * to properly mourn us..
816 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
822 * This does two things:
824 * A. Make init inherit all the child processes
825 * B. Check to see if any process groups have become orphaned
826 * as a result of our exiting, and if they have any stopped
827 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
829 forget_original_parent(tsk
);
830 exit_task_namespaces(tsk
);
832 write_lock_irq(&tasklist_lock
);
834 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
836 /* Let father know we died
838 * Thread signals are configurable, but you aren't going to use
839 * that to send signals to arbitary processes.
840 * That stops right now.
842 * If the parent exec id doesn't match the exec id we saved
843 * when we started then we know the parent has changed security
846 * If our self_exec id doesn't match our parent_exec_id then
847 * we have changed execution domain as these two values started
848 * the same after a fork.
850 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
851 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
852 tsk
->self_exec_id
!= tsk
->parent_exec_id
))
853 tsk
->exit_signal
= SIGCHLD
;
855 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
857 signal
= do_notify_parent(tsk
, signal
);
859 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
861 /* mt-exec, de_thread() is waiting for group leader */
862 if (unlikely(tsk
->signal
->notify_count
< 0))
863 wake_up_process(tsk
->signal
->group_exit_task
);
864 write_unlock_irq(&tasklist_lock
);
866 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
868 /* If the process is dead, release it - nobody will wait for it */
869 if (signal
== DEATH_REAP
)
873 #ifdef CONFIG_DEBUG_STACK_USAGE
874 static void check_stack_usage(void)
876 static DEFINE_SPINLOCK(low_water_lock
);
877 static int lowest_to_date
= THREAD_SIZE
;
880 free
= stack_not_used(current
);
882 if (free
>= lowest_to_date
)
885 spin_lock(&low_water_lock
);
886 if (free
< lowest_to_date
) {
887 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
889 current
->comm
, free
);
890 lowest_to_date
= free
;
892 spin_unlock(&low_water_lock
);
895 static inline void check_stack_usage(void) {}
898 NORET_TYPE
void do_exit(long code
)
900 struct task_struct
*tsk
= current
;
903 profile_task_exit(tsk
);
905 WARN_ON(atomic_read(&tsk
->fs_excl
));
907 if (unlikely(in_interrupt()))
908 panic("Aiee, killing interrupt handler!");
909 if (unlikely(!tsk
->pid
))
910 panic("Attempted to kill the idle task!");
912 tracehook_report_exit(&code
);
914 validate_creds_for_do_exit(tsk
);
917 * We're taking recursive faults here in do_exit. Safest is to just
918 * leave this task alone and wait for reboot.
920 if (unlikely(tsk
->flags
& PF_EXITING
)) {
922 "Fixing recursive fault but reboot is needed!\n");
924 * We can do this unlocked here. The futex code uses
925 * this flag just to verify whether the pi state
926 * cleanup has been done or not. In the worst case it
927 * loops once more. We pretend that the cleanup was
928 * done as there is no way to return. Either the
929 * OWNER_DIED bit is set by now or we push the blocked
930 * task into the wait for ever nirwana as well.
932 tsk
->flags
|= PF_EXITPIDONE
;
933 set_current_state(TASK_UNINTERRUPTIBLE
);
939 exit_signals(tsk
); /* sets PF_EXITING */
941 * tsk->flags are checked in the futex code to protect against
942 * an exiting task cleaning up the robust pi futexes.
945 raw_spin_unlock_wait(&tsk
->pi_lock
);
947 if (unlikely(in_atomic()))
948 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
949 current
->comm
, task_pid_nr(current
),
952 acct_update_integrals(tsk
);
953 /* sync mm's RSS info before statistics gathering */
955 sync_mm_rss(tsk
, tsk
->mm
);
956 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
958 hrtimer_cancel(&tsk
->signal
->real_timer
);
959 exit_itimers(tsk
->signal
);
961 setmax_mm_hiwater_rss(&tsk
->signal
->maxrss
, tsk
->mm
);
963 acct_collect(code
, group_dead
);
966 if (unlikely(tsk
->audit_context
))
969 tsk
->exit_code
= code
;
970 taskstats_exit(tsk
, group_dead
);
976 trace_sched_process_exit(tsk
);
986 disassociate_ctty(1);
988 module_put(task_thread_info(tsk
)->exec_domain
->module
);
990 proc_exit_connector(tsk
);
993 * FIXME: do that only when needed, using sched_exit tracepoint
995 flush_ptrace_hw_breakpoint(tsk
);
997 * Flush inherited counters to the parent - before the parent
998 * gets woken up by child-exit notifications.
1000 perf_event_exit_task(tsk
);
1002 exit_notify(tsk
, group_dead
);
1005 mpol_put(tsk
->mempolicy
);
1006 tsk
->mempolicy
= NULL
;
1010 if (unlikely(current
->pi_state_cache
))
1011 kfree(current
->pi_state_cache
);
1014 * Make sure we are holding no locks:
1016 debug_check_no_locks_held(tsk
);
1018 * We can do this unlocked here. The futex code uses this flag
1019 * just to verify whether the pi state cleanup has been done
1020 * or not. In the worst case it loops once more.
1022 tsk
->flags
|= PF_EXITPIDONE
;
1024 if (tsk
->io_context
)
1025 exit_io_context(tsk
);
1027 if (tsk
->splice_pipe
)
1028 __free_pipe_info(tsk
->splice_pipe
);
1030 validate_creds_for_do_exit(tsk
);
1034 /* causes final put_task_struct in finish_task_switch(). */
1035 tsk
->state
= TASK_DEAD
;
1038 /* Avoid "noreturn function does return". */
1040 cpu_relax(); /* For when BUG is null */
1043 EXPORT_SYMBOL_GPL(do_exit
);
1045 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1053 EXPORT_SYMBOL(complete_and_exit
);
1055 SYSCALL_DEFINE1(exit
, int, error_code
)
1057 do_exit((error_code
&0xff)<<8);
1061 * Take down every thread in the group. This is called by fatal signals
1062 * as well as by sys_exit_group (below).
1065 do_group_exit(int exit_code
)
1067 struct signal_struct
*sig
= current
->signal
;
1069 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1071 if (signal_group_exit(sig
))
1072 exit_code
= sig
->group_exit_code
;
1073 else if (!thread_group_empty(current
)) {
1074 struct sighand_struct
*const sighand
= current
->sighand
;
1075 spin_lock_irq(&sighand
->siglock
);
1076 if (signal_group_exit(sig
))
1077 /* Another thread got here before we took the lock. */
1078 exit_code
= sig
->group_exit_code
;
1080 sig
->group_exit_code
= exit_code
;
1081 sig
->flags
= SIGNAL_GROUP_EXIT
;
1082 zap_other_threads(current
);
1084 spin_unlock_irq(&sighand
->siglock
);
1092 * this kills every thread in the thread group. Note that any externally
1093 * wait4()-ing process will get the correct exit code - even if this
1094 * thread is not the thread group leader.
1096 SYSCALL_DEFINE1(exit_group
, int, error_code
)
1098 do_group_exit((error_code
& 0xff) << 8);
1104 enum pid_type wo_type
;
1108 struct siginfo __user
*wo_info
;
1109 int __user
*wo_stat
;
1110 struct rusage __user
*wo_rusage
;
1112 wait_queue_t child_wait
;
1117 struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1119 if (type
!= PIDTYPE_PID
)
1120 task
= task
->group_leader
;
1121 return task
->pids
[type
].pid
;
1124 static int eligible_pid(struct wait_opts
*wo
, struct task_struct
*p
)
1126 return wo
->wo_type
== PIDTYPE_MAX
||
1127 task_pid_type(p
, wo
->wo_type
) == wo
->wo_pid
;
1130 static int eligible_child(struct wait_opts
*wo
, struct task_struct
*p
)
1132 if (!eligible_pid(wo
, p
))
1134 /* Wait for all children (clone and not) if __WALL is set;
1135 * otherwise, wait for clone children *only* if __WCLONE is
1136 * set; otherwise, wait for non-clone children *only*. (Note:
1137 * A "clone" child here is one that reports to its parent
1138 * using a signal other than SIGCHLD.) */
1139 if (((p
->exit_signal
!= SIGCHLD
) ^ !!(wo
->wo_flags
& __WCLONE
))
1140 && !(wo
->wo_flags
& __WALL
))
1146 static int wait_noreap_copyout(struct wait_opts
*wo
, struct task_struct
*p
,
1147 pid_t pid
, uid_t uid
, int why
, int status
)
1149 struct siginfo __user
*infop
;
1150 int retval
= wo
->wo_rusage
1151 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1154 infop
= wo
->wo_info
;
1157 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1159 retval
= put_user(0, &infop
->si_errno
);
1161 retval
= put_user((short)why
, &infop
->si_code
);
1163 retval
= put_user(pid
, &infop
->si_pid
);
1165 retval
= put_user(uid
, &infop
->si_uid
);
1167 retval
= put_user(status
, &infop
->si_status
);
1175 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1176 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1177 * the lock and this task is uninteresting. If we return nonzero, we have
1178 * released the lock and the system call should return.
1180 static int wait_task_zombie(struct wait_opts
*wo
, struct task_struct
*p
)
1182 unsigned long state
;
1183 int retval
, status
, traced
;
1184 pid_t pid
= task_pid_vnr(p
);
1185 uid_t uid
= __task_cred(p
)->uid
;
1186 struct siginfo __user
*infop
;
1188 if (!likely(wo
->wo_flags
& WEXITED
))
1191 if (unlikely(wo
->wo_flags
& WNOWAIT
)) {
1192 int exit_code
= p
->exit_code
;
1196 read_unlock(&tasklist_lock
);
1197 if ((exit_code
& 0x7f) == 0) {
1199 status
= exit_code
>> 8;
1201 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1202 status
= exit_code
& 0x7f;
1204 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, status
);
1208 * Try to move the task's state to DEAD
1209 * only one thread is allowed to do this:
1211 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1212 if (state
!= EXIT_ZOMBIE
) {
1213 BUG_ON(state
!= EXIT_DEAD
);
1217 traced
= ptrace_reparented(p
);
1219 * It can be ptraced but not reparented, check
1220 * !task_detached() to filter out sub-threads.
1222 if (likely(!traced
) && likely(!task_detached(p
))) {
1223 struct signal_struct
*psig
;
1224 struct signal_struct
*sig
;
1225 unsigned long maxrss
;
1226 cputime_t tgutime
, tgstime
;
1229 * The resource counters for the group leader are in its
1230 * own task_struct. Those for dead threads in the group
1231 * are in its signal_struct, as are those for the child
1232 * processes it has previously reaped. All these
1233 * accumulate in the parent's signal_struct c* fields.
1235 * We don't bother to take a lock here to protect these
1236 * p->signal fields, because they are only touched by
1237 * __exit_signal, which runs with tasklist_lock
1238 * write-locked anyway, and so is excluded here. We do
1239 * need to protect the access to parent->signal fields,
1240 * as other threads in the parent group can be right
1241 * here reaping other children at the same time.
1243 * We use thread_group_times() to get times for the thread
1244 * group, which consolidates times for all threads in the
1245 * group including the group leader.
1247 thread_group_times(p
, &tgutime
, &tgstime
);
1248 spin_lock_irq(&p
->real_parent
->sighand
->siglock
);
1249 psig
= p
->real_parent
->signal
;
1252 cputime_add(psig
->cutime
,
1253 cputime_add(tgutime
,
1256 cputime_add(psig
->cstime
,
1257 cputime_add(tgstime
,
1260 cputime_add(psig
->cgtime
,
1261 cputime_add(p
->gtime
,
1262 cputime_add(sig
->gtime
,
1265 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1267 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1269 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1271 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1273 task_io_get_inblock(p
) +
1274 sig
->inblock
+ sig
->cinblock
;
1276 task_io_get_oublock(p
) +
1277 sig
->oublock
+ sig
->coublock
;
1278 maxrss
= max(sig
->maxrss
, sig
->cmaxrss
);
1279 if (psig
->cmaxrss
< maxrss
)
1280 psig
->cmaxrss
= maxrss
;
1281 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1282 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1283 spin_unlock_irq(&p
->real_parent
->sighand
->siglock
);
1287 * Now we are sure this task is interesting, and no other
1288 * thread can reap it because we set its state to EXIT_DEAD.
1290 read_unlock(&tasklist_lock
);
1292 retval
= wo
->wo_rusage
1293 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1294 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1295 ? p
->signal
->group_exit_code
: p
->exit_code
;
1296 if (!retval
&& wo
->wo_stat
)
1297 retval
= put_user(status
, wo
->wo_stat
);
1299 infop
= wo
->wo_info
;
1300 if (!retval
&& infop
)
1301 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1302 if (!retval
&& infop
)
1303 retval
= put_user(0, &infop
->si_errno
);
1304 if (!retval
&& infop
) {
1307 if ((status
& 0x7f) == 0) {
1311 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1314 retval
= put_user((short)why
, &infop
->si_code
);
1316 retval
= put_user(status
, &infop
->si_status
);
1318 if (!retval
&& infop
)
1319 retval
= put_user(pid
, &infop
->si_pid
);
1320 if (!retval
&& infop
)
1321 retval
= put_user(uid
, &infop
->si_uid
);
1326 write_lock_irq(&tasklist_lock
);
1327 /* We dropped tasklist, ptracer could die and untrace */
1330 * If this is not a detached task, notify the parent.
1331 * If it's still not detached after that, don't release
1334 if (!task_detached(p
)) {
1335 do_notify_parent(p
, p
->exit_signal
);
1336 if (!task_detached(p
)) {
1337 p
->exit_state
= EXIT_ZOMBIE
;
1341 write_unlock_irq(&tasklist_lock
);
1349 static int *task_stopped_code(struct task_struct
*p
, bool ptrace
)
1352 if (task_is_stopped_or_traced(p
))
1353 return &p
->exit_code
;
1355 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
)
1356 return &p
->signal
->group_exit_code
;
1362 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1363 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1364 * the lock and this task is uninteresting. If we return nonzero, we have
1365 * released the lock and the system call should return.
1367 static int wait_task_stopped(struct wait_opts
*wo
,
1368 int ptrace
, struct task_struct
*p
)
1370 struct siginfo __user
*infop
;
1371 int retval
, exit_code
, *p_code
, why
;
1372 uid_t uid
= 0; /* unneeded, required by compiler */
1376 * Traditionally we see ptrace'd stopped tasks regardless of options.
1378 if (!ptrace
&& !(wo
->wo_flags
& WUNTRACED
))
1382 spin_lock_irq(&p
->sighand
->siglock
);
1384 p_code
= task_stopped_code(p
, ptrace
);
1385 if (unlikely(!p_code
))
1388 exit_code
= *p_code
;
1392 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1395 /* don't need the RCU readlock here as we're holding a spinlock */
1396 uid
= __task_cred(p
)->uid
;
1398 spin_unlock_irq(&p
->sighand
->siglock
);
1403 * Now we are pretty sure this task is interesting.
1404 * Make sure it doesn't get reaped out from under us while we
1405 * give up the lock and then examine it below. We don't want to
1406 * keep holding onto the tasklist_lock while we call getrusage and
1407 * possibly take page faults for user memory.
1410 pid
= task_pid_vnr(p
);
1411 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1412 read_unlock(&tasklist_lock
);
1414 if (unlikely(wo
->wo_flags
& WNOWAIT
))
1415 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, exit_code
);
1417 retval
= wo
->wo_rusage
1418 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1419 if (!retval
&& wo
->wo_stat
)
1420 retval
= put_user((exit_code
<< 8) | 0x7f, wo
->wo_stat
);
1422 infop
= wo
->wo_info
;
1423 if (!retval
&& infop
)
1424 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1425 if (!retval
&& infop
)
1426 retval
= put_user(0, &infop
->si_errno
);
1427 if (!retval
&& infop
)
1428 retval
= put_user((short)why
, &infop
->si_code
);
1429 if (!retval
&& infop
)
1430 retval
= put_user(exit_code
, &infop
->si_status
);
1431 if (!retval
&& infop
)
1432 retval
= put_user(pid
, &infop
->si_pid
);
1433 if (!retval
&& infop
)
1434 retval
= put_user(uid
, &infop
->si_uid
);
1444 * Handle do_wait work for one task in a live, non-stopped state.
1445 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1446 * the lock and this task is uninteresting. If we return nonzero, we have
1447 * released the lock and the system call should return.
1449 static int wait_task_continued(struct wait_opts
*wo
, struct task_struct
*p
)
1455 if (!unlikely(wo
->wo_flags
& WCONTINUED
))
1458 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1461 spin_lock_irq(&p
->sighand
->siglock
);
1462 /* Re-check with the lock held. */
1463 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1464 spin_unlock_irq(&p
->sighand
->siglock
);
1467 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1468 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1469 uid
= __task_cred(p
)->uid
;
1470 spin_unlock_irq(&p
->sighand
->siglock
);
1472 pid
= task_pid_vnr(p
);
1474 read_unlock(&tasklist_lock
);
1477 retval
= wo
->wo_rusage
1478 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1480 if (!retval
&& wo
->wo_stat
)
1481 retval
= put_user(0xffff, wo
->wo_stat
);
1485 retval
= wait_noreap_copyout(wo
, p
, pid
, uid
,
1486 CLD_CONTINUED
, SIGCONT
);
1487 BUG_ON(retval
== 0);
1494 * Consider @p for a wait by @parent.
1496 * -ECHILD should be in ->notask_error before the first call.
1497 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1498 * Returns zero if the search for a child should continue;
1499 * then ->notask_error is 0 if @p is an eligible child,
1500 * or another error from security_task_wait(), or still -ECHILD.
1502 static int wait_consider_task(struct wait_opts
*wo
, int ptrace
,
1503 struct task_struct
*p
)
1505 int ret
= eligible_child(wo
, p
);
1509 ret
= security_task_wait(p
);
1510 if (unlikely(ret
< 0)) {
1512 * If we have not yet seen any eligible child,
1513 * then let this error code replace -ECHILD.
1514 * A permission error will give the user a clue
1515 * to look for security policy problems, rather
1516 * than for mysterious wait bugs.
1518 if (wo
->notask_error
)
1519 wo
->notask_error
= ret
;
1523 if (likely(!ptrace
) && unlikely(task_ptrace(p
))) {
1525 * This child is hidden by ptrace.
1526 * We aren't allowed to see it now, but eventually we will.
1528 wo
->notask_error
= 0;
1532 if (p
->exit_state
== EXIT_DEAD
)
1536 * We don't reap group leaders with subthreads.
1538 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1539 return wait_task_zombie(wo
, p
);
1542 * It's stopped or running now, so it might
1543 * later continue, exit, or stop again.
1545 wo
->notask_error
= 0;
1547 if (task_stopped_code(p
, ptrace
))
1548 return wait_task_stopped(wo
, ptrace
, p
);
1550 return wait_task_continued(wo
, p
);
1554 * Do the work of do_wait() for one thread in the group, @tsk.
1556 * -ECHILD should be in ->notask_error before the first call.
1557 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1558 * Returns zero if the search for a child should continue; then
1559 * ->notask_error is 0 if there were any eligible children,
1560 * or another error from security_task_wait(), or still -ECHILD.
1562 static int do_wait_thread(struct wait_opts
*wo
, struct task_struct
*tsk
)
1564 struct task_struct
*p
;
1566 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1567 int ret
= wait_consider_task(wo
, 0, p
);
1575 static int ptrace_do_wait(struct wait_opts
*wo
, struct task_struct
*tsk
)
1577 struct task_struct
*p
;
1579 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1580 int ret
= wait_consider_task(wo
, 1, p
);
1588 static int child_wait_callback(wait_queue_t
*wait
, unsigned mode
,
1589 int sync
, void *key
)
1591 struct wait_opts
*wo
= container_of(wait
, struct wait_opts
,
1593 struct task_struct
*p
= key
;
1595 if (!eligible_pid(wo
, p
))
1598 if ((wo
->wo_flags
& __WNOTHREAD
) && wait
->private != p
->parent
)
1601 return default_wake_function(wait
, mode
, sync
, key
);
1604 void __wake_up_parent(struct task_struct
*p
, struct task_struct
*parent
)
1606 __wake_up_sync_key(&parent
->signal
->wait_chldexit
,
1607 TASK_INTERRUPTIBLE
, 1, p
);
1610 static long do_wait(struct wait_opts
*wo
)
1612 struct task_struct
*tsk
;
1615 trace_sched_process_wait(wo
->wo_pid
);
1617 init_waitqueue_func_entry(&wo
->child_wait
, child_wait_callback
);
1618 wo
->child_wait
.private = current
;
1619 add_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1622 * If there is nothing that can match our critiera just get out.
1623 * We will clear ->notask_error to zero if we see any child that
1624 * might later match our criteria, even if we are not able to reap
1627 wo
->notask_error
= -ECHILD
;
1628 if ((wo
->wo_type
< PIDTYPE_MAX
) &&
1629 (!wo
->wo_pid
|| hlist_empty(&wo
->wo_pid
->tasks
[wo
->wo_type
])))
1632 set_current_state(TASK_INTERRUPTIBLE
);
1633 read_lock(&tasklist_lock
);
1636 retval
= do_wait_thread(wo
, tsk
);
1640 retval
= ptrace_do_wait(wo
, tsk
);
1644 if (wo
->wo_flags
& __WNOTHREAD
)
1646 } while_each_thread(current
, tsk
);
1647 read_unlock(&tasklist_lock
);
1650 retval
= wo
->notask_error
;
1651 if (!retval
&& !(wo
->wo_flags
& WNOHANG
)) {
1652 retval
= -ERESTARTSYS
;
1653 if (!signal_pending(current
)) {
1659 __set_current_state(TASK_RUNNING
);
1660 remove_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1664 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1665 infop
, int, options
, struct rusage __user
*, ru
)
1667 struct wait_opts wo
;
1668 struct pid
*pid
= NULL
;
1672 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1674 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1687 type
= PIDTYPE_PGID
;
1695 if (type
< PIDTYPE_MAX
)
1696 pid
= find_get_pid(upid
);
1700 wo
.wo_flags
= options
;
1710 * For a WNOHANG return, clear out all the fields
1711 * we would set so the user can easily tell the
1715 ret
= put_user(0, &infop
->si_signo
);
1717 ret
= put_user(0, &infop
->si_errno
);
1719 ret
= put_user(0, &infop
->si_code
);
1721 ret
= put_user(0, &infop
->si_pid
);
1723 ret
= put_user(0, &infop
->si_uid
);
1725 ret
= put_user(0, &infop
->si_status
);
1730 /* avoid REGPARM breakage on x86: */
1731 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1735 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1736 int, options
, struct rusage __user
*, ru
)
1738 struct wait_opts wo
;
1739 struct pid
*pid
= NULL
;
1743 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1744 __WNOTHREAD
|__WCLONE
|__WALL
))
1749 else if (upid
< 0) {
1750 type
= PIDTYPE_PGID
;
1751 pid
= find_get_pid(-upid
);
1752 } else if (upid
== 0) {
1753 type
= PIDTYPE_PGID
;
1754 pid
= get_task_pid(current
, PIDTYPE_PGID
);
1755 } else /* upid > 0 */ {
1757 pid
= find_get_pid(upid
);
1762 wo
.wo_flags
= options
| WEXITED
;
1764 wo
.wo_stat
= stat_addr
;
1769 /* avoid REGPARM breakage on x86: */
1770 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1774 #ifdef __ARCH_WANT_SYS_WAITPID
1777 * sys_waitpid() remains for compatibility. waitpid() should be
1778 * implemented by calling sys_wait4() from libc.a.
1780 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1782 return sys_wait4(pid
, stat_addr
, options
, NULL
);
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