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/mnt_namespace.h>
16 #include <linux/iocontext.h>
17 #include <linux/key.h>
18 #include <linux/security.h>
19 #include <linux/cpu.h>
20 #include <linux/acct.h>
21 #include <linux/tsacct_kern.h>
22 #include <linux/file.h>
23 #include <linux/fdtable.h>
24 #include <linux/binfmts.h>
25 #include <linux/nsproxy.h>
26 #include <linux/pid_namespace.h>
27 #include <linux/ptrace.h>
28 #include <linux/profile.h>
29 #include <linux/mount.h>
30 #include <linux/proc_fs.h>
31 #include <linux/kthread.h>
32 #include <linux/mempolicy.h>
33 #include <linux/taskstats_kern.h>
34 #include <linux/delayacct.h>
35 #include <linux/freezer.h>
36 #include <linux/cgroup.h>
37 #include <linux/syscalls.h>
38 #include <linux/signal.h>
39 #include <linux/posix-timers.h>
40 #include <linux/cn_proc.h>
41 #include <linux/mutex.h>
42 #include <linux/futex.h>
43 #include <linux/pipe_fs_i.h>
44 #include <linux/audit.h> /* for audit_free() */
45 #include <linux/resource.h>
46 #include <linux/blkdev.h>
47 #include <linux/task_io_accounting_ops.h>
48 #include <linux/tracehook.h>
49 #include <trace/sched.h>
51 #include <asm/uaccess.h>
52 #include <asm/unistd.h>
53 #include <asm/pgtable.h>
54 #include <asm/mmu_context.h>
56 static void exit_mm(struct task_struct
* tsk
);
58 static inline int task_detached(struct task_struct
*p
)
60 return p
->exit_signal
== -1;
63 static void __unhash_process(struct task_struct
*p
)
66 detach_pid(p
, PIDTYPE_PID
);
67 if (thread_group_leader(p
)) {
68 detach_pid(p
, PIDTYPE_PGID
);
69 detach_pid(p
, PIDTYPE_SID
);
71 list_del_rcu(&p
->tasks
);
72 __get_cpu_var(process_counts
)--;
74 list_del_rcu(&p
->thread_group
);
75 list_del_init(&p
->sibling
);
79 * This function expects the tasklist_lock write-locked.
81 static void __exit_signal(struct task_struct
*tsk
)
83 struct signal_struct
*sig
= tsk
->signal
;
84 struct sighand_struct
*sighand
;
87 BUG_ON(!atomic_read(&sig
->count
));
89 sighand
= rcu_dereference(tsk
->sighand
);
90 spin_lock(&sighand
->siglock
);
92 posix_cpu_timers_exit(tsk
);
93 if (atomic_dec_and_test(&sig
->count
))
94 posix_cpu_timers_exit_group(tsk
);
97 * If there is any task waiting for the group exit
100 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
101 wake_up_process(sig
->group_exit_task
);
103 if (tsk
== sig
->curr_target
)
104 sig
->curr_target
= next_thread(tsk
);
106 * Accumulate here the counters for all threads but the
107 * group leader as they die, so they can be added into
108 * the process-wide totals when those are taken.
109 * The group leader stays around as a zombie as long
110 * as there are other threads. When it gets reaped,
111 * the exit.c code will add its counts into these totals.
112 * We won't ever get here for the group leader, since it
113 * will have been the last reference on the signal_struct.
115 sig
->gtime
= cputime_add(sig
->gtime
, task_gtime(tsk
));
116 sig
->min_flt
+= tsk
->min_flt
;
117 sig
->maj_flt
+= tsk
->maj_flt
;
118 sig
->nvcsw
+= tsk
->nvcsw
;
119 sig
->nivcsw
+= tsk
->nivcsw
;
120 sig
->inblock
+= task_io_get_inblock(tsk
);
121 sig
->oublock
+= task_io_get_oublock(tsk
);
122 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
123 sig
= NULL
; /* Marker for below. */
126 __unhash_process(tsk
);
129 * Do this under ->siglock, we can race with another thread
130 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
132 flush_sigqueue(&tsk
->pending
);
136 spin_unlock(&sighand
->siglock
);
138 __cleanup_sighand(sighand
);
139 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
141 flush_sigqueue(&sig
->shared_pending
);
142 taskstats_tgid_free(sig
);
144 * Make sure ->signal can't go away under rq->lock,
145 * see account_group_exec_runtime().
147 task_rq_unlock_wait(tsk
);
148 __cleanup_signal(sig
);
152 static void delayed_put_task_struct(struct rcu_head
*rhp
)
154 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
156 trace_sched_process_free(tsk
);
157 put_task_struct(tsk
);
161 void release_task(struct task_struct
* p
)
163 struct task_struct
*leader
;
166 tracehook_prepare_release_task(p
);
167 atomic_dec(&p
->user
->processes
);
169 write_lock_irq(&tasklist_lock
);
170 tracehook_finish_release_task(p
);
174 * If we are the last non-leader member of the thread
175 * group, and the leader is zombie, then notify the
176 * group leader's parent process. (if it wants notification.)
179 leader
= p
->group_leader
;
180 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
181 BUG_ON(task_detached(leader
));
182 do_notify_parent(leader
, leader
->exit_signal
);
184 * If we were the last child thread and the leader has
185 * exited already, and the leader's parent ignores SIGCHLD,
186 * then we are the one who should release the leader.
188 * do_notify_parent() will have marked it self-reaping in
191 zap_leader
= task_detached(leader
);
194 * This maintains the invariant that release_task()
195 * only runs on a task in EXIT_DEAD, just for sanity.
198 leader
->exit_state
= EXIT_DEAD
;
201 write_unlock_irq(&tasklist_lock
);
203 call_rcu(&p
->rcu
, delayed_put_task_struct
);
206 if (unlikely(zap_leader
))
211 * This checks not only the pgrp, but falls back on the pid if no
212 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
215 * The caller must hold rcu lock or the tasklist lock.
217 struct pid
*session_of_pgrp(struct pid
*pgrp
)
219 struct task_struct
*p
;
220 struct pid
*sid
= NULL
;
222 p
= pid_task(pgrp
, PIDTYPE_PGID
);
224 p
= pid_task(pgrp
, PIDTYPE_PID
);
226 sid
= task_session(p
);
232 * Determine if a process group is "orphaned", according to the POSIX
233 * definition in 2.2.2.52. Orphaned process groups are not to be affected
234 * by terminal-generated stop signals. Newly orphaned process groups are
235 * to receive a SIGHUP and a SIGCONT.
237 * "I ask you, have you ever known what it is to be an orphan?"
239 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
241 struct task_struct
*p
;
243 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
244 if ((p
== ignored_task
) ||
245 (p
->exit_state
&& thread_group_empty(p
)) ||
246 is_global_init(p
->real_parent
))
249 if (task_pgrp(p
->real_parent
) != pgrp
&&
250 task_session(p
->real_parent
) == task_session(p
))
252 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
257 int is_current_pgrp_orphaned(void)
261 read_lock(&tasklist_lock
);
262 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
263 read_unlock(&tasklist_lock
);
268 static int has_stopped_jobs(struct pid
*pgrp
)
271 struct task_struct
*p
;
273 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
274 if (!task_is_stopped(p
))
278 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
283 * Check to see if any process groups have become orphaned as
284 * a result of our exiting, and if they have any stopped jobs,
285 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
288 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
290 struct pid
*pgrp
= task_pgrp(tsk
);
291 struct task_struct
*ignored_task
= tsk
;
294 /* exit: our father is in a different pgrp than
295 * we are and we were the only connection outside.
297 parent
= tsk
->real_parent
;
299 /* reparent: our child is in a different pgrp than
300 * we are, and it was the only connection outside.
304 if (task_pgrp(parent
) != pgrp
&&
305 task_session(parent
) == task_session(tsk
) &&
306 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
307 has_stopped_jobs(pgrp
)) {
308 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
309 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
314 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
316 * If a kernel thread is launched as a result of a system call, or if
317 * it ever exits, it should generally reparent itself to kthreadd so it
318 * isn't in the way of other processes and is correctly cleaned up on exit.
320 * The various task state such as scheduling policy and priority may have
321 * been inherited from a user process, so we reset them to sane values here.
323 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
325 static void reparent_to_kthreadd(void)
327 write_lock_irq(&tasklist_lock
);
329 ptrace_unlink(current
);
330 /* Reparent to init */
331 current
->real_parent
= current
->parent
= kthreadd_task
;
332 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
334 /* Set the exit signal to SIGCHLD so we signal init on exit */
335 current
->exit_signal
= SIGCHLD
;
337 if (task_nice(current
) < 0)
338 set_user_nice(current
, 0);
342 security_task_reparent_to_init(current
);
343 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
344 sizeof(current
->signal
->rlim
));
345 atomic_inc(&(INIT_USER
->__count
));
346 write_unlock_irq(&tasklist_lock
);
347 switch_uid(INIT_USER
);
350 void __set_special_pids(struct pid
*pid
)
352 struct task_struct
*curr
= current
->group_leader
;
353 pid_t nr
= pid_nr(pid
);
355 if (task_session(curr
) != pid
) {
356 change_pid(curr
, PIDTYPE_SID
, pid
);
357 set_task_session(curr
, nr
);
359 if (task_pgrp(curr
) != pid
) {
360 change_pid(curr
, PIDTYPE_PGID
, pid
);
361 set_task_pgrp(curr
, nr
);
365 static void set_special_pids(struct pid
*pid
)
367 write_lock_irq(&tasklist_lock
);
368 __set_special_pids(pid
);
369 write_unlock_irq(&tasklist_lock
);
373 * Let kernel threads use this to say that they
374 * allow a certain signal (since daemonize() will
375 * have disabled all of them by default).
377 int allow_signal(int sig
)
379 if (!valid_signal(sig
) || sig
< 1)
382 spin_lock_irq(¤t
->sighand
->siglock
);
383 sigdelset(¤t
->blocked
, sig
);
385 /* Kernel threads handle their own signals.
386 Let the signal code know it'll be handled, so
387 that they don't get converted to SIGKILL or
388 just silently dropped */
389 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
392 spin_unlock_irq(¤t
->sighand
->siglock
);
396 EXPORT_SYMBOL(allow_signal
);
398 int disallow_signal(int sig
)
400 if (!valid_signal(sig
) || sig
< 1)
403 spin_lock_irq(¤t
->sighand
->siglock
);
404 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
406 spin_unlock_irq(¤t
->sighand
->siglock
);
410 EXPORT_SYMBOL(disallow_signal
);
413 * Put all the gunge required to become a kernel thread without
414 * attached user resources in one place where it belongs.
417 void daemonize(const char *name
, ...)
420 struct fs_struct
*fs
;
423 va_start(args
, name
);
424 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
428 * If we were started as result of loading a module, close all of the
429 * user space pages. We don't need them, and if we didn't close them
430 * they would be locked into memory.
434 * We don't want to have TIF_FREEZE set if the system-wide hibernation
435 * or suspend transition begins right now.
437 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
439 if (current
->nsproxy
!= &init_nsproxy
) {
440 get_nsproxy(&init_nsproxy
);
441 switch_task_namespaces(current
, &init_nsproxy
);
443 set_special_pids(&init_struct_pid
);
444 proc_clear_tty(current
);
446 /* Block and flush all signals */
447 sigfillset(&blocked
);
448 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
449 flush_signals(current
);
451 /* Become as one with the init task */
453 exit_fs(current
); /* current->fs->count--; */
456 atomic_inc(&fs
->count
);
459 current
->files
= init_task
.files
;
460 atomic_inc(¤t
->files
->count
);
462 reparent_to_kthreadd();
465 EXPORT_SYMBOL(daemonize
);
467 static void close_files(struct files_struct
* files
)
475 * It is safe to dereference the fd table without RCU or
476 * ->file_lock because this is the last reference to the
479 fdt
= files_fdtable(files
);
483 if (i
>= fdt
->max_fds
)
485 set
= fdt
->open_fds
->fds_bits
[j
++];
488 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
490 filp_close(file
, files
);
500 struct files_struct
*get_files_struct(struct task_struct
*task
)
502 struct files_struct
*files
;
507 atomic_inc(&files
->count
);
513 void put_files_struct(struct files_struct
*files
)
517 if (atomic_dec_and_test(&files
->count
)) {
520 * Free the fd and fdset arrays if we expanded them.
521 * If the fdtable was embedded, pass files for freeing
522 * at the end of the RCU grace period. Otherwise,
523 * you can free files immediately.
525 fdt
= files_fdtable(files
);
526 if (fdt
!= &files
->fdtab
)
527 kmem_cache_free(files_cachep
, files
);
532 void reset_files_struct(struct files_struct
*files
)
534 struct task_struct
*tsk
= current
;
535 struct files_struct
*old
;
541 put_files_struct(old
);
544 void exit_files(struct task_struct
*tsk
)
546 struct files_struct
* files
= tsk
->files
;
552 put_files_struct(files
);
556 void put_fs_struct(struct fs_struct
*fs
)
558 /* No need to hold fs->lock if we are killing it */
559 if (atomic_dec_and_test(&fs
->count
)) {
562 kmem_cache_free(fs_cachep
, fs
);
566 void exit_fs(struct task_struct
*tsk
)
568 struct fs_struct
* fs
= tsk
->fs
;
578 EXPORT_SYMBOL_GPL(exit_fs
);
580 #ifdef CONFIG_MM_OWNER
582 * Task p is exiting and it owned mm, lets find a new owner for it
585 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
588 * If there are other users of the mm and the owner (us) is exiting
589 * we need to find a new owner to take on the responsibility.
591 if (atomic_read(&mm
->mm_users
) <= 1)
598 void mm_update_next_owner(struct mm_struct
*mm
)
600 struct task_struct
*c
, *g
, *p
= current
;
603 if (!mm_need_new_owner(mm
, p
))
606 read_lock(&tasklist_lock
);
608 * Search in the children
610 list_for_each_entry(c
, &p
->children
, sibling
) {
612 goto assign_new_owner
;
616 * Search in the siblings
618 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
620 goto assign_new_owner
;
624 * Search through everything else. We should not get
627 do_each_thread(g
, c
) {
629 goto assign_new_owner
;
630 } while_each_thread(g
, c
);
632 read_unlock(&tasklist_lock
);
634 * We found no owner yet mm_users > 1: this implies that we are
635 * most likely racing with swapoff (try_to_unuse()) or /proc or
636 * ptrace or page migration (get_task_mm()). Mark owner as NULL,
637 * so that subsystems can understand the callback and take action.
639 down_write(&mm
->mmap_sem
);
640 cgroup_mm_owner_callbacks(mm
->owner
, NULL
);
642 up_write(&mm
->mmap_sem
);
648 read_unlock(&tasklist_lock
);
649 down_write(&mm
->mmap_sem
);
651 * The task_lock protects c->mm from changing.
652 * We always want mm->owner->mm == mm
657 up_write(&mm
->mmap_sem
);
661 cgroup_mm_owner_callbacks(mm
->owner
, c
);
664 up_write(&mm
->mmap_sem
);
667 #endif /* CONFIG_MM_OWNER */
670 * Turn us into a lazy TLB process if we
673 static void exit_mm(struct task_struct
* tsk
)
675 struct mm_struct
*mm
= tsk
->mm
;
676 struct core_state
*core_state
;
682 * Serialize with any possible pending coredump.
683 * We must hold mmap_sem around checking core_state
684 * and clearing tsk->mm. The core-inducing thread
685 * will increment ->nr_threads for each thread in the
686 * group with ->mm != NULL.
688 down_read(&mm
->mmap_sem
);
689 core_state
= mm
->core_state
;
691 struct core_thread self
;
692 up_read(&mm
->mmap_sem
);
695 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
697 * Implies mb(), the result of xchg() must be visible
698 * to core_state->dumper.
700 if (atomic_dec_and_test(&core_state
->nr_threads
))
701 complete(&core_state
->startup
);
704 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
705 if (!self
.task
) /* see coredump_finish() */
709 __set_task_state(tsk
, TASK_RUNNING
);
710 down_read(&mm
->mmap_sem
);
712 atomic_inc(&mm
->mm_count
);
713 BUG_ON(mm
!= tsk
->active_mm
);
714 /* more a memory barrier than a real lock */
717 up_read(&mm
->mmap_sem
);
718 enter_lazy_tlb(mm
, current
);
719 /* We don't want this task to be frozen prematurely */
720 clear_freeze_flag(tsk
);
722 mm_update_next_owner(mm
);
727 * Return nonzero if @parent's children should reap themselves.
729 * Called with write_lock_irq(&tasklist_lock) held.
731 static int ignoring_children(struct task_struct
*parent
)
734 struct sighand_struct
*psig
= parent
->sighand
;
736 spin_lock_irqsave(&psig
->siglock
, flags
);
737 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
738 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
739 spin_unlock_irqrestore(&psig
->siglock
, flags
);
744 * Detach all tasks we were using ptrace on.
745 * Any that need to be release_task'd are put on the @dead list.
747 * Called with write_lock(&tasklist_lock) held.
749 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
751 struct task_struct
*p
, *n
;
754 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
757 if (p
->exit_state
!= EXIT_ZOMBIE
)
761 * If it's a zombie, our attachedness prevented normal
762 * parent notification or self-reaping. Do notification
763 * now if it would have happened earlier. If it should
764 * reap itself, add it to the @dead list. We can't call
765 * release_task() here because we already hold tasklist_lock.
767 * If it's our own child, there is no notification to do.
768 * But if our normal children self-reap, then this child
769 * was prevented by ptrace and we must reap it now.
771 if (!task_detached(p
) && thread_group_empty(p
)) {
772 if (!same_thread_group(p
->real_parent
, parent
))
773 do_notify_parent(p
, p
->exit_signal
);
776 ign
= ignoring_children(parent
);
782 if (task_detached(p
)) {
784 * Mark it as in the process of being reaped.
786 p
->exit_state
= EXIT_DEAD
;
787 list_add(&p
->ptrace_entry
, dead
);
793 * Finish up exit-time ptrace cleanup.
795 * Called without locks.
797 static void ptrace_exit_finish(struct task_struct
*parent
,
798 struct list_head
*dead
)
800 struct task_struct
*p
, *n
;
802 BUG_ON(!list_empty(&parent
->ptraced
));
804 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
805 list_del_init(&p
->ptrace_entry
);
810 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
812 if (p
->pdeath_signal
)
813 /* We already hold the tasklist_lock here. */
814 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
816 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
818 /* If this is a threaded reparent there is no need to
819 * notify anyone anything has happened.
821 if (same_thread_group(p
->real_parent
, father
))
824 /* We don't want people slaying init. */
825 if (!task_detached(p
))
826 p
->exit_signal
= SIGCHLD
;
828 /* If we'd notified the old parent about this child's death,
829 * also notify the new parent.
831 if (!ptrace_reparented(p
) &&
832 p
->exit_state
== EXIT_ZOMBIE
&&
833 !task_detached(p
) && thread_group_empty(p
))
834 do_notify_parent(p
, p
->exit_signal
);
836 kill_orphaned_pgrp(p
, father
);
840 * When we die, we re-parent all our children.
841 * Try to give them to another thread in our thread
842 * group, and if no such member exists, give it to
843 * the child reaper process (ie "init") in our pid
846 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
848 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
849 struct task_struct
*thread
;
852 while_each_thread(father
, thread
) {
853 if (thread
->flags
& PF_EXITING
)
855 if (unlikely(pid_ns
->child_reaper
== father
))
856 pid_ns
->child_reaper
= thread
;
860 if (unlikely(pid_ns
->child_reaper
== father
)) {
861 write_unlock_irq(&tasklist_lock
);
862 if (unlikely(pid_ns
== &init_pid_ns
))
863 panic("Attempted to kill init!");
865 zap_pid_ns_processes(pid_ns
);
866 write_lock_irq(&tasklist_lock
);
868 * We can not clear ->child_reaper or leave it alone.
869 * There may by stealth EXIT_DEAD tasks on ->children,
870 * forget_original_parent() must move them somewhere.
872 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
875 return pid_ns
->child_reaper
;
878 static void forget_original_parent(struct task_struct
*father
)
880 struct task_struct
*p
, *n
, *reaper
;
881 LIST_HEAD(ptrace_dead
);
883 write_lock_irq(&tasklist_lock
);
884 reaper
= find_new_reaper(father
);
886 * First clean up ptrace if we were using it.
888 ptrace_exit(father
, &ptrace_dead
);
890 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
891 p
->real_parent
= reaper
;
892 if (p
->parent
== father
) {
894 p
->parent
= p
->real_parent
;
896 reparent_thread(p
, father
);
899 write_unlock_irq(&tasklist_lock
);
900 BUG_ON(!list_empty(&father
->children
));
902 ptrace_exit_finish(father
, &ptrace_dead
);
906 * Send signals to all our closest relatives so that they know
907 * to properly mourn us..
909 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
915 * This does two things:
917 * A. Make init inherit all the child processes
918 * B. Check to see if any process groups have become orphaned
919 * as a result of our exiting, and if they have any stopped
920 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
922 forget_original_parent(tsk
);
923 exit_task_namespaces(tsk
);
925 write_lock_irq(&tasklist_lock
);
927 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
929 /* Let father know we died
931 * Thread signals are configurable, but you aren't going to use
932 * that to send signals to arbitary processes.
933 * That stops right now.
935 * If the parent exec id doesn't match the exec id we saved
936 * when we started then we know the parent has changed security
939 * If our self_exec id doesn't match our parent_exec_id then
940 * we have changed execution domain as these two values started
941 * the same after a fork.
943 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
944 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
945 tsk
->self_exec_id
!= tsk
->parent_exec_id
))
946 tsk
->exit_signal
= SIGCHLD
;
948 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
950 signal
= do_notify_parent(tsk
, signal
);
952 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
954 /* mt-exec, de_thread() is waiting for us */
955 if (thread_group_leader(tsk
) &&
956 tsk
->signal
->group_exit_task
&&
957 tsk
->signal
->notify_count
< 0)
958 wake_up_process(tsk
->signal
->group_exit_task
);
960 write_unlock_irq(&tasklist_lock
);
962 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
964 /* If the process is dead, release it - nobody will wait for it */
965 if (signal
== DEATH_REAP
)
969 #ifdef CONFIG_DEBUG_STACK_USAGE
970 static void check_stack_usage(void)
972 static DEFINE_SPINLOCK(low_water_lock
);
973 static int lowest_to_date
= THREAD_SIZE
;
974 unsigned long *n
= end_of_stack(current
);
979 free
= (unsigned long)n
- (unsigned long)end_of_stack(current
);
981 if (free
>= lowest_to_date
)
984 spin_lock(&low_water_lock
);
985 if (free
< lowest_to_date
) {
986 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
988 current
->comm
, free
);
989 lowest_to_date
= free
;
991 spin_unlock(&low_water_lock
);
994 static inline void check_stack_usage(void) {}
997 NORET_TYPE
void do_exit(long code
)
999 struct task_struct
*tsk
= current
;
1002 profile_task_exit(tsk
);
1004 WARN_ON(atomic_read(&tsk
->fs_excl
));
1006 if (unlikely(in_interrupt()))
1007 panic("Aiee, killing interrupt handler!");
1008 if (unlikely(!tsk
->pid
))
1009 panic("Attempted to kill the idle task!");
1011 tracehook_report_exit(&code
);
1014 * We're taking recursive faults here in do_exit. Safest is to just
1015 * leave this task alone and wait for reboot.
1017 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1019 "Fixing recursive fault but reboot is needed!\n");
1021 * We can do this unlocked here. The futex code uses
1022 * this flag just to verify whether the pi state
1023 * cleanup has been done or not. In the worst case it
1024 * loops once more. We pretend that the cleanup was
1025 * done as there is no way to return. Either the
1026 * OWNER_DIED bit is set by now or we push the blocked
1027 * task into the wait for ever nirwana as well.
1029 tsk
->flags
|= PF_EXITPIDONE
;
1030 if (tsk
->io_context
)
1032 set_current_state(TASK_UNINTERRUPTIBLE
);
1036 exit_signals(tsk
); /* sets PF_EXITING */
1038 * tsk->flags are checked in the futex code to protect against
1039 * an exiting task cleaning up the robust pi futexes.
1042 spin_unlock_wait(&tsk
->pi_lock
);
1044 if (unlikely(in_atomic()))
1045 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1046 current
->comm
, task_pid_nr(current
),
1049 acct_update_integrals(tsk
);
1051 update_hiwater_rss(tsk
->mm
);
1052 update_hiwater_vm(tsk
->mm
);
1054 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1056 hrtimer_cancel(&tsk
->signal
->real_timer
);
1057 exit_itimers(tsk
->signal
);
1059 acct_collect(code
, group_dead
);
1062 if (unlikely(tsk
->audit_context
))
1065 tsk
->exit_code
= code
;
1066 taskstats_exit(tsk
, group_dead
);
1072 trace_sched_process_exit(tsk
);
1077 check_stack_usage();
1079 cgroup_exit(tsk
, 1);
1082 if (group_dead
&& tsk
->signal
->leader
)
1083 disassociate_ctty(1);
1085 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1087 module_put(tsk
->binfmt
->module
);
1089 proc_exit_connector(tsk
);
1090 exit_notify(tsk
, group_dead
);
1092 mpol_put(tsk
->mempolicy
);
1093 tsk
->mempolicy
= NULL
;
1097 * This must happen late, after the PID is not
1100 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1101 exit_pi_state_list(tsk
);
1102 if (unlikely(current
->pi_state_cache
))
1103 kfree(current
->pi_state_cache
);
1106 * Make sure we are holding no locks:
1108 debug_check_no_locks_held(tsk
);
1110 * We can do this unlocked here. The futex code uses this flag
1111 * just to verify whether the pi state cleanup has been done
1112 * or not. In the worst case it loops once more.
1114 tsk
->flags
|= PF_EXITPIDONE
;
1116 if (tsk
->io_context
)
1119 if (tsk
->splice_pipe
)
1120 __free_pipe_info(tsk
->splice_pipe
);
1123 /* causes final put_task_struct in finish_task_switch(). */
1124 tsk
->state
= TASK_DEAD
;
1128 /* Avoid "noreturn function does return". */
1130 cpu_relax(); /* For when BUG is null */
1133 EXPORT_SYMBOL_GPL(do_exit
);
1135 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1143 EXPORT_SYMBOL(complete_and_exit
);
1145 SYSCALL_DEFINE1(exit
, int, error_code
)
1147 do_exit((error_code
&0xff)<<8);
1151 * Take down every thread in the group. This is called by fatal signals
1152 * as well as by sys_exit_group (below).
1155 do_group_exit(int exit_code
)
1157 struct signal_struct
*sig
= current
->signal
;
1159 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1161 if (signal_group_exit(sig
))
1162 exit_code
= sig
->group_exit_code
;
1163 else if (!thread_group_empty(current
)) {
1164 struct sighand_struct
*const sighand
= current
->sighand
;
1165 spin_lock_irq(&sighand
->siglock
);
1166 if (signal_group_exit(sig
))
1167 /* Another thread got here before we took the lock. */
1168 exit_code
= sig
->group_exit_code
;
1170 sig
->group_exit_code
= exit_code
;
1171 sig
->flags
= SIGNAL_GROUP_EXIT
;
1172 zap_other_threads(current
);
1174 spin_unlock_irq(&sighand
->siglock
);
1182 * this kills every thread in the thread group. Note that any externally
1183 * wait4()-ing process will get the correct exit code - even if this
1184 * thread is not the thread group leader.
1186 SYSCALL_DEFINE1(exit_group
, int, error_code
)
1188 do_group_exit((error_code
& 0xff) << 8);
1193 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1195 struct pid
*pid
= NULL
;
1196 if (type
== PIDTYPE_PID
)
1197 pid
= task
->pids
[type
].pid
;
1198 else if (type
< PIDTYPE_MAX
)
1199 pid
= task
->group_leader
->pids
[type
].pid
;
1203 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1204 struct task_struct
*p
)
1208 if (type
< PIDTYPE_MAX
) {
1209 if (task_pid_type(p
, type
) != pid
)
1213 /* Wait for all children (clone and not) if __WALL is set;
1214 * otherwise, wait for clone children *only* if __WCLONE is
1215 * set; otherwise, wait for non-clone children *only*. (Note:
1216 * A "clone" child here is one that reports to its parent
1217 * using a signal other than SIGCHLD.) */
1218 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1219 && !(options
& __WALL
))
1222 err
= security_task_wait(p
);
1229 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1230 int why
, int status
,
1231 struct siginfo __user
*infop
,
1232 struct rusage __user
*rusagep
)
1234 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1238 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1240 retval
= put_user(0, &infop
->si_errno
);
1242 retval
= put_user((short)why
, &infop
->si_code
);
1244 retval
= put_user(pid
, &infop
->si_pid
);
1246 retval
= put_user(uid
, &infop
->si_uid
);
1248 retval
= put_user(status
, &infop
->si_status
);
1255 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1256 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1257 * the lock and this task is uninteresting. If we return nonzero, we have
1258 * released the lock and the system call should return.
1260 static int wait_task_zombie(struct task_struct
*p
, int options
,
1261 struct siginfo __user
*infop
,
1262 int __user
*stat_addr
, struct rusage __user
*ru
)
1264 unsigned long state
;
1265 int retval
, status
, traced
;
1266 pid_t pid
= task_pid_vnr(p
);
1268 if (!likely(options
& WEXITED
))
1271 if (unlikely(options
& WNOWAIT
)) {
1273 int exit_code
= p
->exit_code
;
1277 read_unlock(&tasklist_lock
);
1278 if ((exit_code
& 0x7f) == 0) {
1280 status
= exit_code
>> 8;
1282 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1283 status
= exit_code
& 0x7f;
1285 return wait_noreap_copyout(p
, pid
, uid
, why
,
1290 * Try to move the task's state to DEAD
1291 * only one thread is allowed to do this:
1293 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1294 if (state
!= EXIT_ZOMBIE
) {
1295 BUG_ON(state
!= EXIT_DEAD
);
1299 traced
= ptrace_reparented(p
);
1301 if (likely(!traced
)) {
1302 struct signal_struct
*psig
;
1303 struct signal_struct
*sig
;
1304 struct task_cputime cputime
;
1307 * The resource counters for the group leader are in its
1308 * own task_struct. Those for dead threads in the group
1309 * are in its signal_struct, as are those for the child
1310 * processes it has previously reaped. All these
1311 * accumulate in the parent's signal_struct c* fields.
1313 * We don't bother to take a lock here to protect these
1314 * p->signal fields, because they are only touched by
1315 * __exit_signal, which runs with tasklist_lock
1316 * write-locked anyway, and so is excluded here. We do
1317 * need to protect the access to p->parent->signal fields,
1318 * as other threads in the parent group can be right
1319 * here reaping other children at the same time.
1321 * We use thread_group_cputime() to get times for the thread
1322 * group, which consolidates times for all threads in the
1323 * group including the group leader.
1325 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1326 psig
= p
->parent
->signal
;
1328 thread_group_cputime(p
, &cputime
);
1330 cputime_add(psig
->cutime
,
1331 cputime_add(cputime
.utime
,
1334 cputime_add(psig
->cstime
,
1335 cputime_add(cputime
.stime
,
1338 cputime_add(psig
->cgtime
,
1339 cputime_add(p
->gtime
,
1340 cputime_add(sig
->gtime
,
1343 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1345 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1347 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1349 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1351 task_io_get_inblock(p
) +
1352 sig
->inblock
+ sig
->cinblock
;
1354 task_io_get_oublock(p
) +
1355 sig
->oublock
+ sig
->coublock
;
1356 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1357 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1358 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1362 * Now we are sure this task is interesting, and no other
1363 * thread can reap it because we set its state to EXIT_DEAD.
1365 read_unlock(&tasklist_lock
);
1367 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1368 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1369 ? p
->signal
->group_exit_code
: p
->exit_code
;
1370 if (!retval
&& stat_addr
)
1371 retval
= put_user(status
, stat_addr
);
1372 if (!retval
&& infop
)
1373 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1374 if (!retval
&& infop
)
1375 retval
= put_user(0, &infop
->si_errno
);
1376 if (!retval
&& infop
) {
1379 if ((status
& 0x7f) == 0) {
1383 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1386 retval
= put_user((short)why
, &infop
->si_code
);
1388 retval
= put_user(status
, &infop
->si_status
);
1390 if (!retval
&& infop
)
1391 retval
= put_user(pid
, &infop
->si_pid
);
1392 if (!retval
&& infop
)
1393 retval
= put_user(p
->uid
, &infop
->si_uid
);
1398 write_lock_irq(&tasklist_lock
);
1399 /* We dropped tasklist, ptracer could die and untrace */
1402 * If this is not a detached task, notify the parent.
1403 * If it's still not detached after that, don't release
1406 if (!task_detached(p
)) {
1407 do_notify_parent(p
, p
->exit_signal
);
1408 if (!task_detached(p
)) {
1409 p
->exit_state
= EXIT_ZOMBIE
;
1413 write_unlock_irq(&tasklist_lock
);
1422 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1423 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1424 * the lock and this task is uninteresting. If we return nonzero, we have
1425 * released the lock and the system call should return.
1427 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1428 int options
, struct siginfo __user
*infop
,
1429 int __user
*stat_addr
, struct rusage __user
*ru
)
1431 int retval
, exit_code
, why
;
1432 uid_t uid
= 0; /* unneeded, required by compiler */
1435 if (!(options
& WUNTRACED
))
1439 spin_lock_irq(&p
->sighand
->siglock
);
1441 if (unlikely(!task_is_stopped_or_traced(p
)))
1444 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1446 * A group stop is in progress and this is the group leader.
1447 * We won't report until all threads have stopped.
1451 exit_code
= p
->exit_code
;
1455 if (!unlikely(options
& WNOWAIT
))
1460 spin_unlock_irq(&p
->sighand
->siglock
);
1465 * Now we are pretty sure this task is interesting.
1466 * Make sure it doesn't get reaped out from under us while we
1467 * give up the lock and then examine it below. We don't want to
1468 * keep holding onto the tasklist_lock while we call getrusage and
1469 * possibly take page faults for user memory.
1472 pid
= task_pid_vnr(p
);
1473 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1474 read_unlock(&tasklist_lock
);
1476 if (unlikely(options
& WNOWAIT
))
1477 return wait_noreap_copyout(p
, pid
, uid
,
1481 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1482 if (!retval
&& stat_addr
)
1483 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1484 if (!retval
&& infop
)
1485 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1486 if (!retval
&& infop
)
1487 retval
= put_user(0, &infop
->si_errno
);
1488 if (!retval
&& infop
)
1489 retval
= put_user((short)why
, &infop
->si_code
);
1490 if (!retval
&& infop
)
1491 retval
= put_user(exit_code
, &infop
->si_status
);
1492 if (!retval
&& infop
)
1493 retval
= put_user(pid
, &infop
->si_pid
);
1494 if (!retval
&& infop
)
1495 retval
= put_user(uid
, &infop
->si_uid
);
1505 * Handle do_wait work for one task in a live, non-stopped state.
1506 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1507 * the lock and this task is uninteresting. If we return nonzero, we have
1508 * released the lock and the system call should return.
1510 static int wait_task_continued(struct task_struct
*p
, int options
,
1511 struct siginfo __user
*infop
,
1512 int __user
*stat_addr
, struct rusage __user
*ru
)
1518 if (!unlikely(options
& WCONTINUED
))
1521 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1524 spin_lock_irq(&p
->sighand
->siglock
);
1525 /* Re-check with the lock held. */
1526 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1527 spin_unlock_irq(&p
->sighand
->siglock
);
1530 if (!unlikely(options
& WNOWAIT
))
1531 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1532 spin_unlock_irq(&p
->sighand
->siglock
);
1534 pid
= task_pid_vnr(p
);
1537 read_unlock(&tasklist_lock
);
1540 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1542 if (!retval
&& stat_addr
)
1543 retval
= put_user(0xffff, stat_addr
);
1547 retval
= wait_noreap_copyout(p
, pid
, uid
,
1548 CLD_CONTINUED
, SIGCONT
,
1550 BUG_ON(retval
== 0);
1557 * Consider @p for a wait by @parent.
1559 * -ECHILD should be in *@notask_error before the first call.
1560 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1561 * Returns zero if the search for a child should continue;
1562 * then *@notask_error is 0 if @p is an eligible child,
1563 * or another error from security_task_wait(), or still -ECHILD.
1565 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1566 struct task_struct
*p
, int *notask_error
,
1567 enum pid_type type
, struct pid
*pid
, int options
,
1568 struct siginfo __user
*infop
,
1569 int __user
*stat_addr
, struct rusage __user
*ru
)
1571 int ret
= eligible_child(type
, pid
, options
, p
);
1575 if (unlikely(ret
< 0)) {
1577 * If we have not yet seen any eligible child,
1578 * then let this error code replace -ECHILD.
1579 * A permission error will give the user a clue
1580 * to look for security policy problems, rather
1581 * than for mysterious wait bugs.
1584 *notask_error
= ret
;
1587 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1589 * This child is hidden by ptrace.
1590 * We aren't allowed to see it now, but eventually we will.
1596 if (p
->exit_state
== EXIT_DEAD
)
1600 * We don't reap group leaders with subthreads.
1602 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1603 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1606 * It's stopped or running now, so it might
1607 * later continue, exit, or stop again.
1611 if (task_is_stopped_or_traced(p
))
1612 return wait_task_stopped(ptrace
, p
, options
,
1613 infop
, stat_addr
, ru
);
1615 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1619 * Do the work of do_wait() for one thread in the group, @tsk.
1621 * -ECHILD should be in *@notask_error before the first call.
1622 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1623 * Returns zero if the search for a child should continue; then
1624 * *@notask_error is 0 if there were any eligible children,
1625 * or another error from security_task_wait(), or still -ECHILD.
1627 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1628 enum pid_type type
, struct pid
*pid
, int options
,
1629 struct siginfo __user
*infop
, int __user
*stat_addr
,
1630 struct rusage __user
*ru
)
1632 struct task_struct
*p
;
1634 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1636 * Do not consider detached threads.
1638 if (!task_detached(p
)) {
1639 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1641 infop
, stat_addr
, ru
);
1650 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1651 enum pid_type type
, struct pid
*pid
, int options
,
1652 struct siginfo __user
*infop
, int __user
*stat_addr
,
1653 struct rusage __user
*ru
)
1655 struct task_struct
*p
;
1658 * Traditionally we see ptrace'd stopped tasks regardless of options.
1660 options
|= WUNTRACED
;
1662 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1663 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1665 infop
, stat_addr
, ru
);
1673 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1674 struct siginfo __user
*infop
, int __user
*stat_addr
,
1675 struct rusage __user
*ru
)
1677 DECLARE_WAITQUEUE(wait
, current
);
1678 struct task_struct
*tsk
;
1681 trace_sched_process_wait(pid
);
1683 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1686 * If there is nothing that can match our critiera just get out.
1687 * We will clear @retval to zero if we see any child that might later
1688 * match our criteria, even if we are not able to reap it yet.
1691 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1694 current
->state
= TASK_INTERRUPTIBLE
;
1695 read_lock(&tasklist_lock
);
1698 int tsk_result
= do_wait_thread(tsk
, &retval
,
1700 infop
, stat_addr
, ru
);
1702 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1704 infop
, stat_addr
, ru
);
1707 * tasklist_lock is unlocked and we have a final result.
1709 retval
= tsk_result
;
1713 if (options
& __WNOTHREAD
)
1715 tsk
= next_thread(tsk
);
1716 BUG_ON(tsk
->signal
!= current
->signal
);
1717 } while (tsk
!= current
);
1718 read_unlock(&tasklist_lock
);
1720 if (!retval
&& !(options
& WNOHANG
)) {
1721 retval
= -ERESTARTSYS
;
1722 if (!signal_pending(current
)) {
1729 current
->state
= TASK_RUNNING
;
1730 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1736 * For a WNOHANG return, clear out all the fields
1737 * we would set so the user can easily tell the
1741 retval
= put_user(0, &infop
->si_signo
);
1743 retval
= put_user(0, &infop
->si_errno
);
1745 retval
= put_user(0, &infop
->si_code
);
1747 retval
= put_user(0, &infop
->si_pid
);
1749 retval
= put_user(0, &infop
->si_uid
);
1751 retval
= put_user(0, &infop
->si_status
);
1757 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1758 infop
, int, options
, struct rusage __user
*, ru
)
1760 struct pid
*pid
= NULL
;
1764 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1766 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1779 type
= PIDTYPE_PGID
;
1787 if (type
< PIDTYPE_MAX
)
1788 pid
= find_get_pid(upid
);
1789 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1792 /* avoid REGPARM breakage on x86: */
1793 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1797 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1798 int, options
, struct rusage __user
*, ru
)
1800 struct pid
*pid
= NULL
;
1804 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1805 __WNOTHREAD
|__WCLONE
|__WALL
))
1810 else if (upid
< 0) {
1811 type
= PIDTYPE_PGID
;
1812 pid
= find_get_pid(-upid
);
1813 } else if (upid
== 0) {
1814 type
= PIDTYPE_PGID
;
1815 pid
= get_pid(task_pgrp(current
));
1816 } else /* upid > 0 */ {
1818 pid
= find_get_pid(upid
);
1821 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1824 /* avoid REGPARM breakage on x86: */
1825 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1829 #ifdef __ARCH_WANT_SYS_WAITPID
1832 * sys_waitpid() remains for compatibility. waitpid() should be
1833 * implemented by calling sys_wait4() from libc.a.
1835 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1837 return sys_wait4(pid
, stat_addr
, options
, NULL
);