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/compat.h>
44 #include <linux/pipe_fs_i.h>
45 #include <linux/audit.h> /* for audit_free() */
46 #include <linux/resource.h>
47 #include <linux/blkdev.h>
48 #include <linux/task_io_accounting_ops.h>
49 #include <linux/tracehook.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
->utime
= cputime_add(sig
->utime
, tsk
->utime
);
116 sig
->stime
= cputime_add(sig
->stime
, tsk
->stime
);
117 sig
->gtime
= cputime_add(sig
->gtime
, tsk
->gtime
);
118 sig
->min_flt
+= tsk
->min_flt
;
119 sig
->maj_flt
+= tsk
->maj_flt
;
120 sig
->nvcsw
+= tsk
->nvcsw
;
121 sig
->nivcsw
+= tsk
->nivcsw
;
122 sig
->inblock
+= task_io_get_inblock(tsk
);
123 sig
->oublock
+= task_io_get_oublock(tsk
);
124 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
125 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
126 sig
= NULL
; /* Marker for below. */
129 __unhash_process(tsk
);
132 * Do this under ->siglock, we can race with another thread
133 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
135 flush_sigqueue(&tsk
->pending
);
139 spin_unlock(&sighand
->siglock
);
141 __cleanup_sighand(sighand
);
142 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
144 flush_sigqueue(&sig
->shared_pending
);
145 taskstats_tgid_free(sig
);
146 __cleanup_signal(sig
);
150 static void delayed_put_task_struct(struct rcu_head
*rhp
)
152 put_task_struct(container_of(rhp
, struct task_struct
, rcu
));
156 void release_task(struct task_struct
* p
)
158 struct task_struct
*leader
;
161 tracehook_prepare_release_task(p
);
162 atomic_dec(&p
->user
->processes
);
164 write_lock_irq(&tasklist_lock
);
165 tracehook_finish_release_task(p
);
169 * If we are the last non-leader member of the thread
170 * group, and the leader is zombie, then notify the
171 * group leader's parent process. (if it wants notification.)
174 leader
= p
->group_leader
;
175 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
176 BUG_ON(task_detached(leader
));
177 do_notify_parent(leader
, leader
->exit_signal
);
179 * If we were the last child thread and the leader has
180 * exited already, and the leader's parent ignores SIGCHLD,
181 * then we are the one who should release the leader.
183 * do_notify_parent() will have marked it self-reaping in
186 zap_leader
= task_detached(leader
);
189 * This maintains the invariant that release_task()
190 * only runs on a task in EXIT_DEAD, just for sanity.
193 leader
->exit_state
= EXIT_DEAD
;
196 write_unlock_irq(&tasklist_lock
);
198 call_rcu(&p
->rcu
, delayed_put_task_struct
);
201 if (unlikely(zap_leader
))
206 * This checks not only the pgrp, but falls back on the pid if no
207 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
210 * The caller must hold rcu lock or the tasklist lock.
212 struct pid
*session_of_pgrp(struct pid
*pgrp
)
214 struct task_struct
*p
;
215 struct pid
*sid
= NULL
;
217 p
= pid_task(pgrp
, PIDTYPE_PGID
);
219 p
= pid_task(pgrp
, PIDTYPE_PID
);
221 sid
= task_session(p
);
227 * Determine if a process group is "orphaned", according to the POSIX
228 * definition in 2.2.2.52. Orphaned process groups are not to be affected
229 * by terminal-generated stop signals. Newly orphaned process groups are
230 * to receive a SIGHUP and a SIGCONT.
232 * "I ask you, have you ever known what it is to be an orphan?"
234 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
236 struct task_struct
*p
;
238 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
239 if ((p
== ignored_task
) ||
240 (p
->exit_state
&& thread_group_empty(p
)) ||
241 is_global_init(p
->real_parent
))
244 if (task_pgrp(p
->real_parent
) != pgrp
&&
245 task_session(p
->real_parent
) == task_session(p
))
247 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
252 int is_current_pgrp_orphaned(void)
256 read_lock(&tasklist_lock
);
257 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
258 read_unlock(&tasklist_lock
);
263 static int has_stopped_jobs(struct pid
*pgrp
)
266 struct task_struct
*p
;
268 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
269 if (!task_is_stopped(p
))
273 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
278 * Check to see if any process groups have become orphaned as
279 * a result of our exiting, and if they have any stopped jobs,
280 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
283 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
285 struct pid
*pgrp
= task_pgrp(tsk
);
286 struct task_struct
*ignored_task
= tsk
;
289 /* exit: our father is in a different pgrp than
290 * we are and we were the only connection outside.
292 parent
= tsk
->real_parent
;
294 /* reparent: our child is in a different pgrp than
295 * we are, and it was the only connection outside.
299 if (task_pgrp(parent
) != pgrp
&&
300 task_session(parent
) == task_session(tsk
) &&
301 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
302 has_stopped_jobs(pgrp
)) {
303 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
304 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
309 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
311 * If a kernel thread is launched as a result of a system call, or if
312 * it ever exits, it should generally reparent itself to kthreadd so it
313 * isn't in the way of other processes and is correctly cleaned up on exit.
315 * The various task state such as scheduling policy and priority may have
316 * been inherited from a user process, so we reset them to sane values here.
318 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
320 static void reparent_to_kthreadd(void)
322 write_lock_irq(&tasklist_lock
);
324 ptrace_unlink(current
);
325 /* Reparent to init */
326 current
->real_parent
= current
->parent
= kthreadd_task
;
327 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
329 /* Set the exit signal to SIGCHLD so we signal init on exit */
330 current
->exit_signal
= SIGCHLD
;
332 if (task_nice(current
) < 0)
333 set_user_nice(current
, 0);
337 security_task_reparent_to_init(current
);
338 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
339 sizeof(current
->signal
->rlim
));
340 atomic_inc(&(INIT_USER
->__count
));
341 write_unlock_irq(&tasklist_lock
);
342 switch_uid(INIT_USER
);
345 void __set_special_pids(struct pid
*pid
)
347 struct task_struct
*curr
= current
->group_leader
;
348 pid_t nr
= pid_nr(pid
);
350 if (task_session(curr
) != pid
) {
351 change_pid(curr
, PIDTYPE_SID
, pid
);
352 set_task_session(curr
, nr
);
354 if (task_pgrp(curr
) != pid
) {
355 change_pid(curr
, PIDTYPE_PGID
, pid
);
356 set_task_pgrp(curr
, nr
);
360 static void set_special_pids(struct pid
*pid
)
362 write_lock_irq(&tasklist_lock
);
363 __set_special_pids(pid
);
364 write_unlock_irq(&tasklist_lock
);
368 * Let kernel threads use this to say that they
369 * allow a certain signal (since daemonize() will
370 * have disabled all of them by default).
372 int allow_signal(int sig
)
374 if (!valid_signal(sig
) || sig
< 1)
377 spin_lock_irq(¤t
->sighand
->siglock
);
378 sigdelset(¤t
->blocked
, sig
);
380 /* Kernel threads handle their own signals.
381 Let the signal code know it'll be handled, so
382 that they don't get converted to SIGKILL or
383 just silently dropped */
384 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
387 spin_unlock_irq(¤t
->sighand
->siglock
);
391 EXPORT_SYMBOL(allow_signal
);
393 int disallow_signal(int sig
)
395 if (!valid_signal(sig
) || sig
< 1)
398 spin_lock_irq(¤t
->sighand
->siglock
);
399 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
401 spin_unlock_irq(¤t
->sighand
->siglock
);
405 EXPORT_SYMBOL(disallow_signal
);
408 * Put all the gunge required to become a kernel thread without
409 * attached user resources in one place where it belongs.
412 void daemonize(const char *name
, ...)
415 struct fs_struct
*fs
;
418 va_start(args
, name
);
419 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
423 * If we were started as result of loading a module, close all of the
424 * user space pages. We don't need them, and if we didn't close them
425 * they would be locked into memory.
429 * We don't want to have TIF_FREEZE set if the system-wide hibernation
430 * or suspend transition begins right now.
432 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
434 if (current
->nsproxy
!= &init_nsproxy
) {
435 get_nsproxy(&init_nsproxy
);
436 switch_task_namespaces(current
, &init_nsproxy
);
438 set_special_pids(&init_struct_pid
);
439 proc_clear_tty(current
);
441 /* Block and flush all signals */
442 sigfillset(&blocked
);
443 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
444 flush_signals(current
);
446 /* Become as one with the init task */
448 exit_fs(current
); /* current->fs->count--; */
451 atomic_inc(&fs
->count
);
454 current
->files
= init_task
.files
;
455 atomic_inc(¤t
->files
->count
);
457 reparent_to_kthreadd();
460 EXPORT_SYMBOL(daemonize
);
462 static void close_files(struct files_struct
* files
)
470 * It is safe to dereference the fd table without RCU or
471 * ->file_lock because this is the last reference to the
474 fdt
= files_fdtable(files
);
478 if (i
>= fdt
->max_fds
)
480 set
= fdt
->open_fds
->fds_bits
[j
++];
483 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
485 filp_close(file
, files
);
495 struct files_struct
*get_files_struct(struct task_struct
*task
)
497 struct files_struct
*files
;
502 atomic_inc(&files
->count
);
508 void put_files_struct(struct files_struct
*files
)
512 if (atomic_dec_and_test(&files
->count
)) {
515 * Free the fd and fdset arrays if we expanded them.
516 * If the fdtable was embedded, pass files for freeing
517 * at the end of the RCU grace period. Otherwise,
518 * you can free files immediately.
520 fdt
= files_fdtable(files
);
521 if (fdt
!= &files
->fdtab
)
522 kmem_cache_free(files_cachep
, files
);
527 void reset_files_struct(struct files_struct
*files
)
529 struct task_struct
*tsk
= current
;
530 struct files_struct
*old
;
536 put_files_struct(old
);
539 void exit_files(struct task_struct
*tsk
)
541 struct files_struct
* files
= tsk
->files
;
547 put_files_struct(files
);
551 void put_fs_struct(struct fs_struct
*fs
)
553 /* No need to hold fs->lock if we are killing it */
554 if (atomic_dec_and_test(&fs
->count
)) {
557 kmem_cache_free(fs_cachep
, fs
);
561 void exit_fs(struct task_struct
*tsk
)
563 struct fs_struct
* fs
= tsk
->fs
;
573 EXPORT_SYMBOL_GPL(exit_fs
);
575 #ifdef CONFIG_MM_OWNER
577 * Task p is exiting and it owned mm, lets find a new owner for it
580 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
583 * If there are other users of the mm and the owner (us) is exiting
584 * we need to find a new owner to take on the responsibility.
588 if (atomic_read(&mm
->mm_users
) <= 1)
595 void mm_update_next_owner(struct mm_struct
*mm
)
597 struct task_struct
*c
, *g
, *p
= current
;
600 if (!mm_need_new_owner(mm
, p
))
603 read_lock(&tasklist_lock
);
605 * Search in the children
607 list_for_each_entry(c
, &p
->children
, sibling
) {
609 goto assign_new_owner
;
613 * Search in the siblings
615 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
617 goto assign_new_owner
;
621 * Search through everything else. We should not get
624 do_each_thread(g
, c
) {
626 goto assign_new_owner
;
627 } while_each_thread(g
, c
);
629 read_unlock(&tasklist_lock
);
636 * The task_lock protects c->mm from changing.
637 * We always want mm->owner->mm == mm
641 * Delay read_unlock() till we have the task_lock()
642 * to ensure that c does not slip away underneath us
644 read_unlock(&tasklist_lock
);
650 cgroup_mm_owner_callbacks(mm
->owner
, c
);
655 #endif /* CONFIG_MM_OWNER */
658 * Turn us into a lazy TLB process if we
661 static void exit_mm(struct task_struct
* tsk
)
663 struct mm_struct
*mm
= tsk
->mm
;
664 struct core_state
*core_state
;
670 * Serialize with any possible pending coredump.
671 * We must hold mmap_sem around checking core_state
672 * and clearing tsk->mm. The core-inducing thread
673 * will increment ->nr_threads for each thread in the
674 * group with ->mm != NULL.
676 down_read(&mm
->mmap_sem
);
677 core_state
= mm
->core_state
;
679 struct core_thread self
;
680 up_read(&mm
->mmap_sem
);
683 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
685 * Implies mb(), the result of xchg() must be visible
686 * to core_state->dumper.
688 if (atomic_dec_and_test(&core_state
->nr_threads
))
689 complete(&core_state
->startup
);
692 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
693 if (!self
.task
) /* see coredump_finish() */
697 __set_task_state(tsk
, TASK_RUNNING
);
698 down_read(&mm
->mmap_sem
);
700 atomic_inc(&mm
->mm_count
);
701 BUG_ON(mm
!= tsk
->active_mm
);
702 /* more a memory barrier than a real lock */
705 up_read(&mm
->mmap_sem
);
706 enter_lazy_tlb(mm
, current
);
707 /* We don't want this task to be frozen prematurely */
708 clear_freeze_flag(tsk
);
710 mm_update_next_owner(mm
);
715 * Return nonzero if @parent's children should reap themselves.
717 * Called with write_lock_irq(&tasklist_lock) held.
719 static int ignoring_children(struct task_struct
*parent
)
722 struct sighand_struct
*psig
= parent
->sighand
;
724 spin_lock_irqsave(&psig
->siglock
, flags
);
725 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
726 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
727 spin_unlock_irqrestore(&psig
->siglock
, flags
);
732 * Detach all tasks we were using ptrace on.
733 * Any that need to be release_task'd are put on the @dead list.
735 * Called with write_lock(&tasklist_lock) held.
737 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
739 struct task_struct
*p
, *n
;
742 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
745 if (p
->exit_state
!= EXIT_ZOMBIE
)
749 * If it's a zombie, our attachedness prevented normal
750 * parent notification or self-reaping. Do notification
751 * now if it would have happened earlier. If it should
752 * reap itself, add it to the @dead list. We can't call
753 * release_task() here because we already hold tasklist_lock.
755 * If it's our own child, there is no notification to do.
756 * But if our normal children self-reap, then this child
757 * was prevented by ptrace and we must reap it now.
759 if (!task_detached(p
) && thread_group_empty(p
)) {
760 if (!same_thread_group(p
->real_parent
, parent
))
761 do_notify_parent(p
, p
->exit_signal
);
764 ign
= ignoring_children(parent
);
770 if (task_detached(p
)) {
772 * Mark it as in the process of being reaped.
774 p
->exit_state
= EXIT_DEAD
;
775 list_add(&p
->ptrace_entry
, dead
);
781 * Finish up exit-time ptrace cleanup.
783 * Called without locks.
785 static void ptrace_exit_finish(struct task_struct
*parent
,
786 struct list_head
*dead
)
788 struct task_struct
*p
, *n
;
790 BUG_ON(!list_empty(&parent
->ptraced
));
792 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
793 list_del_init(&p
->ptrace_entry
);
798 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
800 if (p
->pdeath_signal
)
801 /* We already hold the tasklist_lock here. */
802 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
804 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
806 /* If this is a threaded reparent there is no need to
807 * notify anyone anything has happened.
809 if (same_thread_group(p
->real_parent
, father
))
812 /* We don't want people slaying init. */
813 if (!task_detached(p
))
814 p
->exit_signal
= SIGCHLD
;
816 /* If we'd notified the old parent about this child's death,
817 * also notify the new parent.
819 if (!ptrace_reparented(p
) &&
820 p
->exit_state
== EXIT_ZOMBIE
&&
821 !task_detached(p
) && thread_group_empty(p
))
822 do_notify_parent(p
, p
->exit_signal
);
824 kill_orphaned_pgrp(p
, father
);
828 * When we die, we re-parent all our children.
829 * Try to give them to another thread in our thread
830 * group, and if no such member exists, give it to
831 * the child reaper process (ie "init") in our pid
834 static void forget_original_parent(struct task_struct
*father
)
836 struct task_struct
*p
, *n
, *reaper
= father
;
837 LIST_HEAD(ptrace_dead
);
839 write_lock_irq(&tasklist_lock
);
842 * First clean up ptrace if we were using it.
844 ptrace_exit(father
, &ptrace_dead
);
847 reaper
= next_thread(reaper
);
848 if (reaper
== father
) {
849 reaper
= task_child_reaper(father
);
852 } while (reaper
->flags
& PF_EXITING
);
854 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
855 p
->real_parent
= reaper
;
856 if (p
->parent
== father
) {
858 p
->parent
= p
->real_parent
;
860 reparent_thread(p
, father
);
863 write_unlock_irq(&tasklist_lock
);
864 BUG_ON(!list_empty(&father
->children
));
866 ptrace_exit_finish(father
, &ptrace_dead
);
870 * Send signals to all our closest relatives so that they know
871 * to properly mourn us..
873 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
879 * This does two things:
881 * A. Make init inherit all the child processes
882 * B. Check to see if any process groups have become orphaned
883 * as a result of our exiting, and if they have any stopped
884 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
886 forget_original_parent(tsk
);
887 exit_task_namespaces(tsk
);
889 write_lock_irq(&tasklist_lock
);
891 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
893 /* Let father know we died
895 * Thread signals are configurable, but you aren't going to use
896 * that to send signals to arbitary processes.
897 * That stops right now.
899 * If the parent exec id doesn't match the exec id we saved
900 * when we started then we know the parent has changed security
903 * If our self_exec id doesn't match our parent_exec_id then
904 * we have changed execution domain as these two values started
905 * the same after a fork.
907 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
908 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
909 tsk
->self_exec_id
!= tsk
->parent_exec_id
) &&
911 tsk
->exit_signal
= SIGCHLD
;
913 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
915 signal
= do_notify_parent(tsk
, signal
);
917 tsk
->exit_state
= signal
< 0 ? EXIT_DEAD
: EXIT_ZOMBIE
;
919 /* mt-exec, de_thread() is waiting for us */
920 if (thread_group_leader(tsk
) &&
921 tsk
->signal
->notify_count
< 0 &&
922 tsk
->signal
->group_exit_task
)
923 wake_up_process(tsk
->signal
->group_exit_task
);
925 write_unlock_irq(&tasklist_lock
);
927 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
929 /* If the process is dead, release it - nobody will wait for it */
934 #ifdef CONFIG_DEBUG_STACK_USAGE
935 static void check_stack_usage(void)
937 static DEFINE_SPINLOCK(low_water_lock
);
938 static int lowest_to_date
= THREAD_SIZE
;
939 unsigned long *n
= end_of_stack(current
);
944 free
= (unsigned long)n
- (unsigned long)end_of_stack(current
);
946 if (free
>= lowest_to_date
)
949 spin_lock(&low_water_lock
);
950 if (free
< lowest_to_date
) {
951 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
953 current
->comm
, free
);
954 lowest_to_date
= free
;
956 spin_unlock(&low_water_lock
);
959 static inline void check_stack_usage(void) {}
962 static inline void exit_child_reaper(struct task_struct
*tsk
)
964 if (likely(tsk
->group_leader
!= task_child_reaper(tsk
)))
967 if (tsk
->nsproxy
->pid_ns
== &init_pid_ns
)
968 panic("Attempted to kill init!");
971 * @tsk is the last thread in the 'cgroup-init' and is exiting.
972 * Terminate all remaining processes in the namespace and reap them
973 * before exiting @tsk.
975 * Note that @tsk (last thread of cgroup-init) may not necessarily
976 * be the child-reaper (i.e main thread of cgroup-init) of the
977 * namespace i.e the child_reaper may have already exited.
979 * Even after a child_reaper exits, we let it inherit orphaned children,
980 * because, pid_ns->child_reaper remains valid as long as there is
981 * at least one living sub-thread in the cgroup init.
983 * This living sub-thread of the cgroup-init will be notified when
984 * a child inherited by the 'child-reaper' exits (do_notify_parent()
985 * uses __group_send_sig_info()). Further, when reaping child processes,
986 * do_wait() iterates over children of all living sub threads.
988 * i.e even though 'child_reaper' thread is listed as the parent of the
989 * orphaned children, any living sub-thread in the cgroup-init can
990 * perform the role of the child_reaper.
992 zap_pid_ns_processes(tsk
->nsproxy
->pid_ns
);
995 NORET_TYPE
void do_exit(long code
)
997 struct task_struct
*tsk
= current
;
1000 profile_task_exit(tsk
);
1002 WARN_ON(atomic_read(&tsk
->fs_excl
));
1004 if (unlikely(in_interrupt()))
1005 panic("Aiee, killing interrupt handler!");
1006 if (unlikely(!tsk
->pid
))
1007 panic("Attempted to kill the idle task!");
1009 tracehook_report_exit(&code
);
1012 * We're taking recursive faults here in do_exit. Safest is to just
1013 * leave this task alone and wait for reboot.
1015 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1017 "Fixing recursive fault but reboot is needed!\n");
1019 * We can do this unlocked here. The futex code uses
1020 * this flag just to verify whether the pi state
1021 * cleanup has been done or not. In the worst case it
1022 * loops once more. We pretend that the cleanup was
1023 * done as there is no way to return. Either the
1024 * OWNER_DIED bit is set by now or we push the blocked
1025 * task into the wait for ever nirwana as well.
1027 tsk
->flags
|= PF_EXITPIDONE
;
1028 if (tsk
->io_context
)
1030 set_current_state(TASK_UNINTERRUPTIBLE
);
1034 exit_signals(tsk
); /* sets PF_EXITING */
1036 * tsk->flags are checked in the futex code to protect against
1037 * an exiting task cleaning up the robust pi futexes.
1040 spin_unlock_wait(&tsk
->pi_lock
);
1042 if (unlikely(in_atomic()))
1043 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1044 current
->comm
, task_pid_nr(current
),
1047 acct_update_integrals(tsk
);
1049 update_hiwater_rss(tsk
->mm
);
1050 update_hiwater_vm(tsk
->mm
);
1052 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1054 exit_child_reaper(tsk
);
1055 hrtimer_cancel(&tsk
->signal
->real_timer
);
1056 exit_itimers(tsk
->signal
);
1058 acct_collect(code
, group_dead
);
1060 if (unlikely(tsk
->robust_list
))
1061 exit_robust_list(tsk
);
1062 #ifdef CONFIG_COMPAT
1063 if (unlikely(tsk
->compat_robust_list
))
1064 compat_exit_robust_list(tsk
);
1069 if (unlikely(tsk
->audit_context
))
1072 tsk
->exit_code
= code
;
1073 taskstats_exit(tsk
, group_dead
);
1082 check_stack_usage();
1084 cgroup_exit(tsk
, 1);
1087 if (group_dead
&& tsk
->signal
->leader
)
1088 disassociate_ctty(1);
1090 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1092 module_put(tsk
->binfmt
->module
);
1094 proc_exit_connector(tsk
);
1095 exit_notify(tsk
, group_dead
);
1097 mpol_put(tsk
->mempolicy
);
1098 tsk
->mempolicy
= NULL
;
1102 * This must happen late, after the PID is not
1105 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1106 exit_pi_state_list(tsk
);
1107 if (unlikely(current
->pi_state_cache
))
1108 kfree(current
->pi_state_cache
);
1111 * Make sure we are holding no locks:
1113 debug_check_no_locks_held(tsk
);
1115 * We can do this unlocked here. The futex code uses this flag
1116 * just to verify whether the pi state cleanup has been done
1117 * or not. In the worst case it loops once more.
1119 tsk
->flags
|= PF_EXITPIDONE
;
1121 if (tsk
->io_context
)
1124 if (tsk
->splice_pipe
)
1125 __free_pipe_info(tsk
->splice_pipe
);
1128 /* causes final put_task_struct in finish_task_switch(). */
1129 tsk
->state
= TASK_DEAD
;
1133 /* Avoid "noreturn function does return". */
1135 cpu_relax(); /* For when BUG is null */
1138 EXPORT_SYMBOL_GPL(do_exit
);
1140 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1148 EXPORT_SYMBOL(complete_and_exit
);
1150 asmlinkage
long sys_exit(int error_code
)
1152 do_exit((error_code
&0xff)<<8);
1156 * Take down every thread in the group. This is called by fatal signals
1157 * as well as by sys_exit_group (below).
1160 do_group_exit(int exit_code
)
1162 struct signal_struct
*sig
= current
->signal
;
1164 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1166 if (signal_group_exit(sig
))
1167 exit_code
= sig
->group_exit_code
;
1168 else if (!thread_group_empty(current
)) {
1169 struct sighand_struct
*const sighand
= current
->sighand
;
1170 spin_lock_irq(&sighand
->siglock
);
1171 if (signal_group_exit(sig
))
1172 /* Another thread got here before we took the lock. */
1173 exit_code
= sig
->group_exit_code
;
1175 sig
->group_exit_code
= exit_code
;
1176 sig
->flags
= SIGNAL_GROUP_EXIT
;
1177 zap_other_threads(current
);
1179 spin_unlock_irq(&sighand
->siglock
);
1187 * this kills every thread in the thread group. Note that any externally
1188 * wait4()-ing process will get the correct exit code - even if this
1189 * thread is not the thread group leader.
1191 asmlinkage
void sys_exit_group(int error_code
)
1193 do_group_exit((error_code
& 0xff) << 8);
1196 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1198 struct pid
*pid
= NULL
;
1199 if (type
== PIDTYPE_PID
)
1200 pid
= task
->pids
[type
].pid
;
1201 else if (type
< PIDTYPE_MAX
)
1202 pid
= task
->group_leader
->pids
[type
].pid
;
1206 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1207 struct task_struct
*p
)
1211 if (type
< PIDTYPE_MAX
) {
1212 if (task_pid_type(p
, type
) != pid
)
1216 /* Wait for all children (clone and not) if __WALL is set;
1217 * otherwise, wait for clone children *only* if __WCLONE is
1218 * set; otherwise, wait for non-clone children *only*. (Note:
1219 * A "clone" child here is one that reports to its parent
1220 * using a signal other than SIGCHLD.) */
1221 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1222 && !(options
& __WALL
))
1225 err
= security_task_wait(p
);
1232 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1233 int why
, int status
,
1234 struct siginfo __user
*infop
,
1235 struct rusage __user
*rusagep
)
1237 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1241 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1243 retval
= put_user(0, &infop
->si_errno
);
1245 retval
= put_user((short)why
, &infop
->si_code
);
1247 retval
= put_user(pid
, &infop
->si_pid
);
1249 retval
= put_user(uid
, &infop
->si_uid
);
1251 retval
= put_user(status
, &infop
->si_status
);
1258 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1259 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1260 * the lock and this task is uninteresting. If we return nonzero, we have
1261 * released the lock and the system call should return.
1263 static int wait_task_zombie(struct task_struct
*p
, int options
,
1264 struct siginfo __user
*infop
,
1265 int __user
*stat_addr
, struct rusage __user
*ru
)
1267 unsigned long state
;
1268 int retval
, status
, traced
;
1269 pid_t pid
= task_pid_vnr(p
);
1271 if (!likely(options
& WEXITED
))
1274 if (unlikely(options
& WNOWAIT
)) {
1276 int exit_code
= p
->exit_code
;
1280 read_unlock(&tasklist_lock
);
1281 if ((exit_code
& 0x7f) == 0) {
1283 status
= exit_code
>> 8;
1285 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1286 status
= exit_code
& 0x7f;
1288 return wait_noreap_copyout(p
, pid
, uid
, why
,
1293 * Try to move the task's state to DEAD
1294 * only one thread is allowed to do this:
1296 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1297 if (state
!= EXIT_ZOMBIE
) {
1298 BUG_ON(state
!= EXIT_DEAD
);
1302 traced
= ptrace_reparented(p
);
1304 if (likely(!traced
)) {
1305 struct signal_struct
*psig
;
1306 struct signal_struct
*sig
;
1309 * The resource counters for the group leader are in its
1310 * own task_struct. Those for dead threads in the group
1311 * are in its signal_struct, as are those for the child
1312 * processes it has previously reaped. All these
1313 * accumulate in the parent's signal_struct c* fields.
1315 * We don't bother to take a lock here to protect these
1316 * p->signal fields, because they are only touched by
1317 * __exit_signal, which runs with tasklist_lock
1318 * write-locked anyway, and so is excluded here. We do
1319 * need to protect the access to p->parent->signal fields,
1320 * as other threads in the parent group can be right
1321 * here reaping other children at the same time.
1323 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1324 psig
= p
->parent
->signal
;
1327 cputime_add(psig
->cutime
,
1328 cputime_add(p
->utime
,
1329 cputime_add(sig
->utime
,
1332 cputime_add(psig
->cstime
,
1333 cputime_add(p
->stime
,
1334 cputime_add(sig
->stime
,
1337 cputime_add(psig
->cgtime
,
1338 cputime_add(p
->gtime
,
1339 cputime_add(sig
->gtime
,
1342 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1344 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1346 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1348 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1350 task_io_get_inblock(p
) +
1351 sig
->inblock
+ sig
->cinblock
;
1353 task_io_get_oublock(p
) +
1354 sig
->oublock
+ sig
->coublock
;
1355 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1356 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1357 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1361 * Now we are sure this task is interesting, and no other
1362 * thread can reap it because we set its state to EXIT_DEAD.
1364 read_unlock(&tasklist_lock
);
1366 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1367 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1368 ? p
->signal
->group_exit_code
: p
->exit_code
;
1369 if (!retval
&& stat_addr
)
1370 retval
= put_user(status
, stat_addr
);
1371 if (!retval
&& infop
)
1372 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1373 if (!retval
&& infop
)
1374 retval
= put_user(0, &infop
->si_errno
);
1375 if (!retval
&& infop
) {
1378 if ((status
& 0x7f) == 0) {
1382 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1385 retval
= put_user((short)why
, &infop
->si_code
);
1387 retval
= put_user(status
, &infop
->si_status
);
1389 if (!retval
&& infop
)
1390 retval
= put_user(pid
, &infop
->si_pid
);
1391 if (!retval
&& infop
)
1392 retval
= put_user(p
->uid
, &infop
->si_uid
);
1397 write_lock_irq(&tasklist_lock
);
1398 /* We dropped tasklist, ptracer could die and untrace */
1401 * If this is not a detached task, notify the parent.
1402 * If it's still not detached after that, don't release
1405 if (!task_detached(p
)) {
1406 do_notify_parent(p
, p
->exit_signal
);
1407 if (!task_detached(p
)) {
1408 p
->exit_state
= EXIT_ZOMBIE
;
1412 write_unlock_irq(&tasklist_lock
);
1421 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1422 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1423 * the lock and this task is uninteresting. If we return nonzero, we have
1424 * released the lock and the system call should return.
1426 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1427 int options
, struct siginfo __user
*infop
,
1428 int __user
*stat_addr
, struct rusage __user
*ru
)
1430 int retval
, exit_code
, why
;
1431 uid_t uid
= 0; /* unneeded, required by compiler */
1434 if (!(options
& WUNTRACED
))
1438 spin_lock_irq(&p
->sighand
->siglock
);
1440 if (unlikely(!task_is_stopped_or_traced(p
)))
1443 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1445 * A group stop is in progress and this is the group leader.
1446 * We won't report until all threads have stopped.
1450 exit_code
= p
->exit_code
;
1454 if (!unlikely(options
& WNOWAIT
))
1459 spin_unlock_irq(&p
->sighand
->siglock
);
1464 * Now we are pretty sure this task is interesting.
1465 * Make sure it doesn't get reaped out from under us while we
1466 * give up the lock and then examine it below. We don't want to
1467 * keep holding onto the tasklist_lock while we call getrusage and
1468 * possibly take page faults for user memory.
1471 pid
= task_pid_vnr(p
);
1472 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1473 read_unlock(&tasklist_lock
);
1475 if (unlikely(options
& WNOWAIT
))
1476 return wait_noreap_copyout(p
, pid
, uid
,
1480 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1481 if (!retval
&& stat_addr
)
1482 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1483 if (!retval
&& infop
)
1484 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1485 if (!retval
&& infop
)
1486 retval
= put_user(0, &infop
->si_errno
);
1487 if (!retval
&& infop
)
1488 retval
= put_user((short)why
, &infop
->si_code
);
1489 if (!retval
&& infop
)
1490 retval
= put_user(exit_code
, &infop
->si_status
);
1491 if (!retval
&& infop
)
1492 retval
= put_user(pid
, &infop
->si_pid
);
1493 if (!retval
&& infop
)
1494 retval
= put_user(uid
, &infop
->si_uid
);
1504 * Handle do_wait work for one task in a live, non-stopped state.
1505 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1506 * the lock and this task is uninteresting. If we return nonzero, we have
1507 * released the lock and the system call should return.
1509 static int wait_task_continued(struct task_struct
*p
, int options
,
1510 struct siginfo __user
*infop
,
1511 int __user
*stat_addr
, struct rusage __user
*ru
)
1517 if (!unlikely(options
& WCONTINUED
))
1520 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1523 spin_lock_irq(&p
->sighand
->siglock
);
1524 /* Re-check with the lock held. */
1525 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1526 spin_unlock_irq(&p
->sighand
->siglock
);
1529 if (!unlikely(options
& WNOWAIT
))
1530 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1531 spin_unlock_irq(&p
->sighand
->siglock
);
1533 pid
= task_pid_vnr(p
);
1536 read_unlock(&tasklist_lock
);
1539 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1541 if (!retval
&& stat_addr
)
1542 retval
= put_user(0xffff, stat_addr
);
1546 retval
= wait_noreap_copyout(p
, pid
, uid
,
1547 CLD_CONTINUED
, SIGCONT
,
1549 BUG_ON(retval
== 0);
1556 * Consider @p for a wait by @parent.
1558 * -ECHILD should be in *@notask_error before the first call.
1559 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1560 * Returns zero if the search for a child should continue;
1561 * then *@notask_error is 0 if @p is an eligible child,
1562 * or another error from security_task_wait(), or still -ECHILD.
1564 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1565 struct task_struct
*p
, int *notask_error
,
1566 enum pid_type type
, struct pid
*pid
, int options
,
1567 struct siginfo __user
*infop
,
1568 int __user
*stat_addr
, struct rusage __user
*ru
)
1570 int ret
= eligible_child(type
, pid
, options
, p
);
1574 if (unlikely(ret
< 0)) {
1576 * If we have not yet seen any eligible child,
1577 * then let this error code replace -ECHILD.
1578 * A permission error will give the user a clue
1579 * to look for security policy problems, rather
1580 * than for mysterious wait bugs.
1583 *notask_error
= ret
;
1586 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1588 * This child is hidden by ptrace.
1589 * We aren't allowed to see it now, but eventually we will.
1595 if (p
->exit_state
== EXIT_DEAD
)
1599 * We don't reap group leaders with subthreads.
1601 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1602 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1605 * It's stopped or running now, so it might
1606 * later continue, exit, or stop again.
1610 if (task_is_stopped_or_traced(p
))
1611 return wait_task_stopped(ptrace
, p
, options
,
1612 infop
, stat_addr
, ru
);
1614 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1618 * Do the work of do_wait() for one thread in the group, @tsk.
1620 * -ECHILD should be in *@notask_error before the first call.
1621 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1622 * Returns zero if the search for a child should continue; then
1623 * *@notask_error is 0 if there were any eligible children,
1624 * or another error from security_task_wait(), or still -ECHILD.
1626 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1627 enum pid_type type
, struct pid
*pid
, int options
,
1628 struct siginfo __user
*infop
, int __user
*stat_addr
,
1629 struct rusage __user
*ru
)
1631 struct task_struct
*p
;
1633 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1635 * Do not consider detached threads.
1637 if (!task_detached(p
)) {
1638 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1640 infop
, stat_addr
, ru
);
1649 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1650 enum pid_type type
, struct pid
*pid
, int options
,
1651 struct siginfo __user
*infop
, int __user
*stat_addr
,
1652 struct rusage __user
*ru
)
1654 struct task_struct
*p
;
1657 * Traditionally we see ptrace'd stopped tasks regardless of options.
1659 options
|= WUNTRACED
;
1661 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1662 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1664 infop
, stat_addr
, ru
);
1672 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1673 struct siginfo __user
*infop
, int __user
*stat_addr
,
1674 struct rusage __user
*ru
)
1676 DECLARE_WAITQUEUE(wait
, current
);
1677 struct task_struct
*tsk
;
1680 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1683 * If there is nothing that can match our critiera just get out.
1684 * We will clear @retval to zero if we see any child that might later
1685 * match our criteria, even if we are not able to reap it yet.
1688 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1691 current
->state
= TASK_INTERRUPTIBLE
;
1692 read_lock(&tasklist_lock
);
1695 int tsk_result
= do_wait_thread(tsk
, &retval
,
1697 infop
, stat_addr
, ru
);
1699 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1701 infop
, stat_addr
, ru
);
1704 * tasklist_lock is unlocked and we have a final result.
1706 retval
= tsk_result
;
1710 if (options
& __WNOTHREAD
)
1712 tsk
= next_thread(tsk
);
1713 BUG_ON(tsk
->signal
!= current
->signal
);
1714 } while (tsk
!= current
);
1715 read_unlock(&tasklist_lock
);
1717 if (!retval
&& !(options
& WNOHANG
)) {
1718 retval
= -ERESTARTSYS
;
1719 if (!signal_pending(current
)) {
1726 current
->state
= TASK_RUNNING
;
1727 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1733 * For a WNOHANG return, clear out all the fields
1734 * we would set so the user can easily tell the
1738 retval
= put_user(0, &infop
->si_signo
);
1740 retval
= put_user(0, &infop
->si_errno
);
1742 retval
= put_user(0, &infop
->si_code
);
1744 retval
= put_user(0, &infop
->si_pid
);
1746 retval
= put_user(0, &infop
->si_uid
);
1748 retval
= put_user(0, &infop
->si_status
);
1754 asmlinkage
long sys_waitid(int which
, pid_t upid
,
1755 struct siginfo __user
*infop
, int options
,
1756 struct rusage __user
*ru
)
1758 struct pid
*pid
= NULL
;
1762 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1764 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1777 type
= PIDTYPE_PGID
;
1785 if (type
< PIDTYPE_MAX
)
1786 pid
= find_get_pid(upid
);
1787 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1790 /* avoid REGPARM breakage on x86: */
1791 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1795 asmlinkage
long sys_wait4(pid_t upid
, int __user
*stat_addr
,
1796 int options
, struct rusage __user
*ru
)
1798 struct pid
*pid
= NULL
;
1802 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1803 __WNOTHREAD
|__WCLONE
|__WALL
))
1808 else if (upid
< 0) {
1809 type
= PIDTYPE_PGID
;
1810 pid
= find_get_pid(-upid
);
1811 } else if (upid
== 0) {
1812 type
= PIDTYPE_PGID
;
1813 pid
= get_pid(task_pgrp(current
));
1814 } else /* upid > 0 */ {
1816 pid
= find_get_pid(upid
);
1819 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1822 /* avoid REGPARM breakage on x86: */
1823 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1827 #ifdef __ARCH_WANT_SYS_WAITPID
1830 * sys_waitpid() remains for compatibility. waitpid() should be
1831 * implemented by calling sys_wait4() from libc.a.
1833 asmlinkage
long sys_waitpid(pid_t pid
, int __user
*stat_addr
, int options
)
1835 return sys_wait4(pid
, stat_addr
, options
, NULL
);