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>
50 #include <asm/uaccess.h>
51 #include <asm/unistd.h>
52 #include <asm/pgtable.h>
53 #include <asm/mmu_context.h>
55 static void exit_mm(struct task_struct
* tsk
);
57 static inline int task_detached(struct task_struct
*p
)
59 return p
->exit_signal
== -1;
62 static void __unhash_process(struct task_struct
*p
)
65 detach_pid(p
, PIDTYPE_PID
);
66 if (thread_group_leader(p
)) {
67 detach_pid(p
, PIDTYPE_PGID
);
68 detach_pid(p
, PIDTYPE_SID
);
70 list_del_rcu(&p
->tasks
);
71 __get_cpu_var(process_counts
)--;
73 list_del_rcu(&p
->thread_group
);
74 list_del_init(&p
->sibling
);
78 * This function expects the tasklist_lock write-locked.
80 static void __exit_signal(struct task_struct
*tsk
)
82 struct signal_struct
*sig
= tsk
->signal
;
83 struct sighand_struct
*sighand
;
86 BUG_ON(!atomic_read(&sig
->count
));
88 sighand
= rcu_dereference(tsk
->sighand
);
89 spin_lock(&sighand
->siglock
);
91 posix_cpu_timers_exit(tsk
);
92 if (atomic_dec_and_test(&sig
->count
))
93 posix_cpu_timers_exit_group(tsk
);
96 * If there is any task waiting for the group exit
99 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
100 wake_up_process(sig
->group_exit_task
);
102 if (tsk
== sig
->curr_target
)
103 sig
->curr_target
= next_thread(tsk
);
105 * Accumulate here the counters for all threads but the
106 * group leader as they die, so they can be added into
107 * the process-wide totals when those are taken.
108 * The group leader stays around as a zombie as long
109 * as there are other threads. When it gets reaped,
110 * the exit.c code will add its counts into these totals.
111 * We won't ever get here for the group leader, since it
112 * will have been the last reference on the signal_struct.
114 sig
->utime
= cputime_add(sig
->utime
, tsk
->utime
);
115 sig
->stime
= cputime_add(sig
->stime
, tsk
->stime
);
116 sig
->gtime
= cputime_add(sig
->gtime
, tsk
->gtime
);
117 sig
->min_flt
+= tsk
->min_flt
;
118 sig
->maj_flt
+= tsk
->maj_flt
;
119 sig
->nvcsw
+= tsk
->nvcsw
;
120 sig
->nivcsw
+= tsk
->nivcsw
;
121 sig
->inblock
+= task_io_get_inblock(tsk
);
122 sig
->oublock
+= task_io_get_oublock(tsk
);
123 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
124 sig
= NULL
; /* Marker for below. */
127 __unhash_process(tsk
);
130 * Do this under ->siglock, we can race with another thread
131 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
133 flush_sigqueue(&tsk
->pending
);
137 spin_unlock(&sighand
->siglock
);
139 __cleanup_sighand(sighand
);
140 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
142 flush_sigqueue(&sig
->shared_pending
);
143 taskstats_tgid_free(sig
);
144 __cleanup_signal(sig
);
148 static void delayed_put_task_struct(struct rcu_head
*rhp
)
150 put_task_struct(container_of(rhp
, struct task_struct
, rcu
));
154 * Do final ptrace-related cleanup of a zombie being reaped.
156 * Called with write_lock(&tasklist_lock) held.
158 static void ptrace_release_task(struct task_struct
*p
)
160 BUG_ON(!list_empty(&p
->ptraced
));
162 BUG_ON(!list_empty(&p
->ptrace_entry
));
165 void release_task(struct task_struct
* p
)
167 struct task_struct
*leader
;
170 atomic_dec(&p
->user
->processes
);
172 write_lock_irq(&tasklist_lock
);
173 ptrace_release_task(p
);
177 * If we are the last non-leader member of the thread
178 * group, and the leader is zombie, then notify the
179 * group leader's parent process. (if it wants notification.)
182 leader
= p
->group_leader
;
183 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
184 BUG_ON(task_detached(leader
));
185 do_notify_parent(leader
, leader
->exit_signal
);
187 * If we were the last child thread and the leader has
188 * exited already, and the leader's parent ignores SIGCHLD,
189 * then we are the one who should release the leader.
191 * do_notify_parent() will have marked it self-reaping in
194 zap_leader
= task_detached(leader
);
197 write_unlock_irq(&tasklist_lock
);
199 call_rcu(&p
->rcu
, delayed_put_task_struct
);
202 if (unlikely(zap_leader
))
207 * This checks not only the pgrp, but falls back on the pid if no
208 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
211 * The caller must hold rcu lock or the tasklist lock.
213 struct pid
*session_of_pgrp(struct pid
*pgrp
)
215 struct task_struct
*p
;
216 struct pid
*sid
= NULL
;
218 p
= pid_task(pgrp
, PIDTYPE_PGID
);
220 p
= pid_task(pgrp
, PIDTYPE_PID
);
222 sid
= task_session(p
);
228 * Determine if a process group is "orphaned", according to the POSIX
229 * definition in 2.2.2.52. Orphaned process groups are not to be affected
230 * by terminal-generated stop signals. Newly orphaned process groups are
231 * to receive a SIGHUP and a SIGCONT.
233 * "I ask you, have you ever known what it is to be an orphan?"
235 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
237 struct task_struct
*p
;
239 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
240 if ((p
== ignored_task
) ||
241 (p
->exit_state
&& thread_group_empty(p
)) ||
242 is_global_init(p
->real_parent
))
245 if (task_pgrp(p
->real_parent
) != pgrp
&&
246 task_session(p
->real_parent
) == task_session(p
))
248 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
253 int is_current_pgrp_orphaned(void)
257 read_lock(&tasklist_lock
);
258 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
259 read_unlock(&tasklist_lock
);
264 static int has_stopped_jobs(struct pid
*pgrp
)
267 struct task_struct
*p
;
269 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
270 if (!task_is_stopped(p
))
274 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
279 * Check to see if any process groups have become orphaned as
280 * a result of our exiting, and if they have any stopped jobs,
281 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
284 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
286 struct pid
*pgrp
= task_pgrp(tsk
);
287 struct task_struct
*ignored_task
= tsk
;
290 /* exit: our father is in a different pgrp than
291 * we are and we were the only connection outside.
293 parent
= tsk
->real_parent
;
295 /* reparent: our child is in a different pgrp than
296 * we are, and it was the only connection outside.
300 if (task_pgrp(parent
) != pgrp
&&
301 task_session(parent
) == task_session(tsk
) &&
302 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
303 has_stopped_jobs(pgrp
)) {
304 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
305 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
310 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
312 * If a kernel thread is launched as a result of a system call, or if
313 * it ever exits, it should generally reparent itself to kthreadd so it
314 * isn't in the way of other processes and is correctly cleaned up on exit.
316 * The various task state such as scheduling policy and priority may have
317 * been inherited from a user process, so we reset them to sane values here.
319 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
321 static void reparent_to_kthreadd(void)
323 write_lock_irq(&tasklist_lock
);
325 ptrace_unlink(current
);
326 /* Reparent to init */
327 current
->real_parent
= current
->parent
= kthreadd_task
;
328 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
330 /* Set the exit signal to SIGCHLD so we signal init on exit */
331 current
->exit_signal
= SIGCHLD
;
333 if (task_nice(current
) < 0)
334 set_user_nice(current
, 0);
338 security_task_reparent_to_init(current
);
339 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
340 sizeof(current
->signal
->rlim
));
341 atomic_inc(&(INIT_USER
->__count
));
342 write_unlock_irq(&tasklist_lock
);
343 switch_uid(INIT_USER
);
346 void __set_special_pids(struct pid
*pid
)
348 struct task_struct
*curr
= current
->group_leader
;
349 pid_t nr
= pid_nr(pid
);
351 if (task_session(curr
) != pid
) {
352 change_pid(curr
, PIDTYPE_SID
, pid
);
353 set_task_session(curr
, nr
);
355 if (task_pgrp(curr
) != pid
) {
356 change_pid(curr
, PIDTYPE_PGID
, pid
);
357 set_task_pgrp(curr
, nr
);
361 static void set_special_pids(struct pid
*pid
)
363 write_lock_irq(&tasklist_lock
);
364 __set_special_pids(pid
);
365 write_unlock_irq(&tasklist_lock
);
369 * Let kernel threads use this to say that they
370 * allow a certain signal (since daemonize() will
371 * have disabled all of them by default).
373 int allow_signal(int sig
)
375 if (!valid_signal(sig
) || sig
< 1)
378 spin_lock_irq(¤t
->sighand
->siglock
);
379 sigdelset(¤t
->blocked
, sig
);
381 /* Kernel threads handle their own signals.
382 Let the signal code know it'll be handled, so
383 that they don't get converted to SIGKILL or
384 just silently dropped */
385 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
388 spin_unlock_irq(¤t
->sighand
->siglock
);
392 EXPORT_SYMBOL(allow_signal
);
394 int disallow_signal(int sig
)
396 if (!valid_signal(sig
) || sig
< 1)
399 spin_lock_irq(¤t
->sighand
->siglock
);
400 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
402 spin_unlock_irq(¤t
->sighand
->siglock
);
406 EXPORT_SYMBOL(disallow_signal
);
409 * Put all the gunge required to become a kernel thread without
410 * attached user resources in one place where it belongs.
413 void daemonize(const char *name
, ...)
416 struct fs_struct
*fs
;
419 va_start(args
, name
);
420 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
424 * If we were started as result of loading a module, close all of the
425 * user space pages. We don't need them, and if we didn't close them
426 * they would be locked into memory.
430 * We don't want to have TIF_FREEZE set if the system-wide hibernation
431 * or suspend transition begins right now.
433 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
435 if (current
->nsproxy
!= &init_nsproxy
) {
436 get_nsproxy(&init_nsproxy
);
437 switch_task_namespaces(current
, &init_nsproxy
);
439 set_special_pids(&init_struct_pid
);
440 proc_clear_tty(current
);
442 /* Block and flush all signals */
443 sigfillset(&blocked
);
444 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
445 flush_signals(current
);
447 /* Become as one with the init task */
449 exit_fs(current
); /* current->fs->count--; */
452 atomic_inc(&fs
->count
);
455 current
->files
= init_task
.files
;
456 atomic_inc(¤t
->files
->count
);
458 reparent_to_kthreadd();
461 EXPORT_SYMBOL(daemonize
);
463 static void close_files(struct files_struct
* files
)
471 * It is safe to dereference the fd table without RCU or
472 * ->file_lock because this is the last reference to the
475 fdt
= files_fdtable(files
);
479 if (i
>= fdt
->max_fds
)
481 set
= fdt
->open_fds
->fds_bits
[j
++];
484 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
486 filp_close(file
, files
);
496 struct files_struct
*get_files_struct(struct task_struct
*task
)
498 struct files_struct
*files
;
503 atomic_inc(&files
->count
);
509 void put_files_struct(struct files_struct
*files
)
513 if (atomic_dec_and_test(&files
->count
)) {
516 * Free the fd and fdset arrays if we expanded them.
517 * If the fdtable was embedded, pass files for freeing
518 * at the end of the RCU grace period. Otherwise,
519 * you can free files immediately.
521 fdt
= files_fdtable(files
);
522 if (fdt
!= &files
->fdtab
)
523 kmem_cache_free(files_cachep
, files
);
528 void reset_files_struct(struct files_struct
*files
)
530 struct task_struct
*tsk
= current
;
531 struct files_struct
*old
;
537 put_files_struct(old
);
540 void exit_files(struct task_struct
*tsk
)
542 struct files_struct
* files
= tsk
->files
;
548 put_files_struct(files
);
552 void put_fs_struct(struct fs_struct
*fs
)
554 /* No need to hold fs->lock if we are killing it */
555 if (atomic_dec_and_test(&fs
->count
)) {
558 if (fs
->altroot
.dentry
)
559 path_put(&fs
->altroot
);
560 kmem_cache_free(fs_cachep
, fs
);
564 void exit_fs(struct task_struct
*tsk
)
566 struct fs_struct
* fs
= tsk
->fs
;
576 EXPORT_SYMBOL_GPL(exit_fs
);
578 #ifdef CONFIG_MM_OWNER
580 * Task p is exiting and it owned mm, lets find a new owner for it
583 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
586 * If there are other users of the mm and the owner (us) is exiting
587 * 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
);
639 * The task_lock protects c->mm from changing.
640 * We always want mm->owner->mm == mm
644 * Delay read_unlock() till we have the task_lock()
645 * to ensure that c does not slip away underneath us
647 read_unlock(&tasklist_lock
);
653 cgroup_mm_owner_callbacks(mm
->owner
, c
);
658 #endif /* CONFIG_MM_OWNER */
661 * Turn us into a lazy TLB process if we
664 static void exit_mm(struct task_struct
* tsk
)
666 struct mm_struct
*mm
= tsk
->mm
;
672 * Serialize with any possible pending coredump.
673 * We must hold mmap_sem around checking core_state
674 * and clearing tsk->mm. The core-inducing thread
675 * will increment ->nr_threads for each thread in the
676 * group with ->mm != NULL.
678 down_read(&mm
->mmap_sem
);
679 if (mm
->core_state
) {
680 up_read(&mm
->mmap_sem
);
682 if (atomic_dec_and_test(&mm
->core_state
->nr_threads
))
683 complete(&mm
->core_state
->startup
);
685 wait_for_completion(&mm
->core_done
);
686 down_read(&mm
->mmap_sem
);
688 atomic_inc(&mm
->mm_count
);
689 BUG_ON(mm
!= tsk
->active_mm
);
690 /* more a memory barrier than a real lock */
693 up_read(&mm
->mmap_sem
);
694 enter_lazy_tlb(mm
, current
);
695 /* We don't want this task to be frozen prematurely */
696 clear_freeze_flag(tsk
);
698 mm_update_next_owner(mm
);
703 * Return nonzero if @parent's children should reap themselves.
705 * Called with write_lock_irq(&tasklist_lock) held.
707 static int ignoring_children(struct task_struct
*parent
)
710 struct sighand_struct
*psig
= parent
->sighand
;
712 spin_lock_irqsave(&psig
->siglock
, flags
);
713 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
714 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
715 spin_unlock_irqrestore(&psig
->siglock
, flags
);
720 * Detach all tasks we were using ptrace on.
721 * Any that need to be release_task'd are put on the @dead list.
723 * Called with write_lock(&tasklist_lock) held.
725 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
727 struct task_struct
*p
, *n
;
730 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
733 if (p
->exit_state
!= EXIT_ZOMBIE
)
737 * If it's a zombie, our attachedness prevented normal
738 * parent notification or self-reaping. Do notification
739 * now if it would have happened earlier. If it should
740 * reap itself, add it to the @dead list. We can't call
741 * release_task() here because we already hold tasklist_lock.
743 * If it's our own child, there is no notification to do.
744 * But if our normal children self-reap, then this child
745 * was prevented by ptrace and we must reap it now.
747 if (!task_detached(p
) && thread_group_empty(p
)) {
748 if (!same_thread_group(p
->real_parent
, parent
))
749 do_notify_parent(p
, p
->exit_signal
);
752 ign
= ignoring_children(parent
);
758 if (task_detached(p
)) {
760 * Mark it as in the process of being reaped.
762 p
->exit_state
= EXIT_DEAD
;
763 list_add(&p
->ptrace_entry
, dead
);
769 * Finish up exit-time ptrace cleanup.
771 * Called without locks.
773 static void ptrace_exit_finish(struct task_struct
*parent
,
774 struct list_head
*dead
)
776 struct task_struct
*p
, *n
;
778 BUG_ON(!list_empty(&parent
->ptraced
));
780 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
781 list_del_init(&p
->ptrace_entry
);
786 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
788 if (p
->pdeath_signal
)
789 /* We already hold the tasklist_lock here. */
790 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
792 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
794 /* If this is a threaded reparent there is no need to
795 * notify anyone anything has happened.
797 if (same_thread_group(p
->real_parent
, father
))
800 /* We don't want people slaying init. */
801 if (!task_detached(p
))
802 p
->exit_signal
= SIGCHLD
;
804 /* If we'd notified the old parent about this child's death,
805 * also notify the new parent.
807 if (!ptrace_reparented(p
) &&
808 p
->exit_state
== EXIT_ZOMBIE
&&
809 !task_detached(p
) && thread_group_empty(p
))
810 do_notify_parent(p
, p
->exit_signal
);
812 kill_orphaned_pgrp(p
, father
);
816 * When we die, we re-parent all our children.
817 * Try to give them to another thread in our thread
818 * group, and if no such member exists, give it to
819 * the child reaper process (ie "init") in our pid
822 static void forget_original_parent(struct task_struct
*father
)
824 struct task_struct
*p
, *n
, *reaper
= father
;
825 LIST_HEAD(ptrace_dead
);
827 write_lock_irq(&tasklist_lock
);
830 * First clean up ptrace if we were using it.
832 ptrace_exit(father
, &ptrace_dead
);
835 reaper
= next_thread(reaper
);
836 if (reaper
== father
) {
837 reaper
= task_child_reaper(father
);
840 } while (reaper
->flags
& PF_EXITING
);
842 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
843 p
->real_parent
= reaper
;
844 if (p
->parent
== father
) {
846 p
->parent
= p
->real_parent
;
848 reparent_thread(p
, father
);
851 write_unlock_irq(&tasklist_lock
);
852 BUG_ON(!list_empty(&father
->children
));
854 ptrace_exit_finish(father
, &ptrace_dead
);
858 * Send signals to all our closest relatives so that they know
859 * to properly mourn us..
861 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
866 * This does two things:
868 * A. Make init inherit all the child processes
869 * B. Check to see if any process groups have become orphaned
870 * as a result of our exiting, and if they have any stopped
871 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
873 forget_original_parent(tsk
);
874 exit_task_namespaces(tsk
);
876 write_lock_irq(&tasklist_lock
);
878 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
880 /* Let father know we died
882 * Thread signals are configurable, but you aren't going to use
883 * that to send signals to arbitary processes.
884 * That stops right now.
886 * If the parent exec id doesn't match the exec id we saved
887 * when we started then we know the parent has changed security
890 * If our self_exec id doesn't match our parent_exec_id then
891 * we have changed execution domain as these two values started
892 * the same after a fork.
894 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
895 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
896 tsk
->self_exec_id
!= tsk
->parent_exec_id
) &&
898 tsk
->exit_signal
= SIGCHLD
;
900 /* If something other than our normal parent is ptracing us, then
901 * send it a SIGCHLD instead of honoring exit_signal. exit_signal
902 * only has special meaning to our real parent.
904 if (!task_detached(tsk
) && thread_group_empty(tsk
)) {
905 int signal
= ptrace_reparented(tsk
) ?
906 SIGCHLD
: tsk
->exit_signal
;
907 do_notify_parent(tsk
, signal
);
908 } else if (tsk
->ptrace
) {
909 do_notify_parent(tsk
, SIGCHLD
);
913 if (task_detached(tsk
) && likely(!tsk
->ptrace
))
915 tsk
->exit_state
= state
;
917 /* mt-exec, de_thread() is waiting for us */
918 if (thread_group_leader(tsk
) &&
919 tsk
->signal
->notify_count
< 0 &&
920 tsk
->signal
->group_exit_task
)
921 wake_up_process(tsk
->signal
->group_exit_task
);
923 write_unlock_irq(&tasklist_lock
);
925 /* If the process is dead, release it - nobody will wait for it */
926 if (state
== EXIT_DEAD
)
930 #ifdef CONFIG_DEBUG_STACK_USAGE
931 static void check_stack_usage(void)
933 static DEFINE_SPINLOCK(low_water_lock
);
934 static int lowest_to_date
= THREAD_SIZE
;
935 unsigned long *n
= end_of_stack(current
);
940 free
= (unsigned long)n
- (unsigned long)end_of_stack(current
);
942 if (free
>= lowest_to_date
)
945 spin_lock(&low_water_lock
);
946 if (free
< lowest_to_date
) {
947 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
949 current
->comm
, free
);
950 lowest_to_date
= free
;
952 spin_unlock(&low_water_lock
);
955 static inline void check_stack_usage(void) {}
958 static inline void exit_child_reaper(struct task_struct
*tsk
)
960 if (likely(tsk
->group_leader
!= task_child_reaper(tsk
)))
963 if (tsk
->nsproxy
->pid_ns
== &init_pid_ns
)
964 panic("Attempted to kill init!");
967 * @tsk is the last thread in the 'cgroup-init' and is exiting.
968 * Terminate all remaining processes in the namespace and reap them
969 * before exiting @tsk.
971 * Note that @tsk (last thread of cgroup-init) may not necessarily
972 * be the child-reaper (i.e main thread of cgroup-init) of the
973 * namespace i.e the child_reaper may have already exited.
975 * Even after a child_reaper exits, we let it inherit orphaned children,
976 * because, pid_ns->child_reaper remains valid as long as there is
977 * at least one living sub-thread in the cgroup init.
979 * This living sub-thread of the cgroup-init will be notified when
980 * a child inherited by the 'child-reaper' exits (do_notify_parent()
981 * uses __group_send_sig_info()). Further, when reaping child processes,
982 * do_wait() iterates over children of all living sub threads.
984 * i.e even though 'child_reaper' thread is listed as the parent of the
985 * orphaned children, any living sub-thread in the cgroup-init can
986 * perform the role of the child_reaper.
988 zap_pid_ns_processes(tsk
->nsproxy
->pid_ns
);
991 NORET_TYPE
void do_exit(long code
)
993 struct task_struct
*tsk
= current
;
996 profile_task_exit(tsk
);
998 WARN_ON(atomic_read(&tsk
->fs_excl
));
1000 if (unlikely(in_interrupt()))
1001 panic("Aiee, killing interrupt handler!");
1002 if (unlikely(!tsk
->pid
))
1003 panic("Attempted to kill the idle task!");
1005 if (unlikely(current
->ptrace
& PT_TRACE_EXIT
)) {
1006 current
->ptrace_message
= code
;
1007 ptrace_notify((PTRACE_EVENT_EXIT
<< 8) | SIGTRAP
);
1011 * We're taking recursive faults here in do_exit. Safest is to just
1012 * leave this task alone and wait for reboot.
1014 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1016 "Fixing recursive fault but reboot is needed!\n");
1018 * We can do this unlocked here. The futex code uses
1019 * this flag just to verify whether the pi state
1020 * cleanup has been done or not. In the worst case it
1021 * loops once more. We pretend that the cleanup was
1022 * done as there is no way to return. Either the
1023 * OWNER_DIED bit is set by now or we push the blocked
1024 * task into the wait for ever nirwana as well.
1026 tsk
->flags
|= PF_EXITPIDONE
;
1027 if (tsk
->io_context
)
1029 set_current_state(TASK_UNINTERRUPTIBLE
);
1033 exit_signals(tsk
); /* sets PF_EXITING */
1035 * tsk->flags are checked in the futex code to protect against
1036 * an exiting task cleaning up the robust pi futexes.
1039 spin_unlock_wait(&tsk
->pi_lock
);
1041 if (unlikely(in_atomic()))
1042 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1043 current
->comm
, task_pid_nr(current
),
1046 acct_update_integrals(tsk
);
1048 update_hiwater_rss(tsk
->mm
);
1049 update_hiwater_vm(tsk
->mm
);
1051 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1053 exit_child_reaper(tsk
);
1054 hrtimer_cancel(&tsk
->signal
->real_timer
);
1055 exit_itimers(tsk
->signal
);
1057 acct_collect(code
, group_dead
);
1059 if (unlikely(tsk
->robust_list
))
1060 exit_robust_list(tsk
);
1061 #ifdef CONFIG_COMPAT
1062 if (unlikely(tsk
->compat_robust_list
))
1063 compat_exit_robust_list(tsk
);
1068 if (unlikely(tsk
->audit_context
))
1071 tsk
->exit_code
= code
;
1072 taskstats_exit(tsk
, group_dead
);
1081 check_stack_usage();
1083 cgroup_exit(tsk
, 1);
1086 if (group_dead
&& tsk
->signal
->leader
)
1087 disassociate_ctty(1);
1089 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1091 module_put(tsk
->binfmt
->module
);
1093 proc_exit_connector(tsk
);
1094 exit_notify(tsk
, group_dead
);
1096 mpol_put(tsk
->mempolicy
);
1097 tsk
->mempolicy
= NULL
;
1101 * This must happen late, after the PID is not
1104 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1105 exit_pi_state_list(tsk
);
1106 if (unlikely(current
->pi_state_cache
))
1107 kfree(current
->pi_state_cache
);
1110 * Make sure we are holding no locks:
1112 debug_check_no_locks_held(tsk
);
1114 * We can do this unlocked here. The futex code uses this flag
1115 * just to verify whether the pi state cleanup has been done
1116 * or not. In the worst case it loops once more.
1118 tsk
->flags
|= PF_EXITPIDONE
;
1120 if (tsk
->io_context
)
1123 if (tsk
->splice_pipe
)
1124 __free_pipe_info(tsk
->splice_pipe
);
1127 /* causes final put_task_struct in finish_task_switch(). */
1128 tsk
->state
= TASK_DEAD
;
1132 /* Avoid "noreturn function does return". */
1134 cpu_relax(); /* For when BUG is null */
1137 EXPORT_SYMBOL_GPL(do_exit
);
1139 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1147 EXPORT_SYMBOL(complete_and_exit
);
1149 asmlinkage
long sys_exit(int error_code
)
1151 do_exit((error_code
&0xff)<<8);
1155 * Take down every thread in the group. This is called by fatal signals
1156 * as well as by sys_exit_group (below).
1159 do_group_exit(int exit_code
)
1161 struct signal_struct
*sig
= current
->signal
;
1163 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1165 if (signal_group_exit(sig
))
1166 exit_code
= sig
->group_exit_code
;
1167 else if (!thread_group_empty(current
)) {
1168 struct sighand_struct
*const sighand
= current
->sighand
;
1169 spin_lock_irq(&sighand
->siglock
);
1170 if (signal_group_exit(sig
))
1171 /* Another thread got here before we took the lock. */
1172 exit_code
= sig
->group_exit_code
;
1174 sig
->group_exit_code
= exit_code
;
1175 sig
->flags
= SIGNAL_GROUP_EXIT
;
1176 zap_other_threads(current
);
1178 spin_unlock_irq(&sighand
->siglock
);
1186 * this kills every thread in the thread group. Note that any externally
1187 * wait4()-ing process will get the correct exit code - even if this
1188 * thread is not the thread group leader.
1190 asmlinkage
void sys_exit_group(int error_code
)
1192 do_group_exit((error_code
& 0xff) << 8);
1195 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1197 struct pid
*pid
= NULL
;
1198 if (type
== PIDTYPE_PID
)
1199 pid
= task
->pids
[type
].pid
;
1200 else if (type
< PIDTYPE_MAX
)
1201 pid
= task
->group_leader
->pids
[type
].pid
;
1205 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1206 struct task_struct
*p
)
1210 if (type
< PIDTYPE_MAX
) {
1211 if (task_pid_type(p
, type
) != pid
)
1215 /* Wait for all children (clone and not) if __WALL is set;
1216 * otherwise, wait for clone children *only* if __WCLONE is
1217 * set; otherwise, wait for non-clone children *only*. (Note:
1218 * A "clone" child here is one that reports to its parent
1219 * using a signal other than SIGCHLD.) */
1220 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1221 && !(options
& __WALL
))
1224 err
= security_task_wait(p
);
1231 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1232 int why
, int status
,
1233 struct siginfo __user
*infop
,
1234 struct rusage __user
*rusagep
)
1236 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1240 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1242 retval
= put_user(0, &infop
->si_errno
);
1244 retval
= put_user((short)why
, &infop
->si_code
);
1246 retval
= put_user(pid
, &infop
->si_pid
);
1248 retval
= put_user(uid
, &infop
->si_uid
);
1250 retval
= put_user(status
, &infop
->si_status
);
1257 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1258 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1259 * the lock and this task is uninteresting. If we return nonzero, we have
1260 * released the lock and the system call should return.
1262 static int wait_task_zombie(struct task_struct
*p
, int options
,
1263 struct siginfo __user
*infop
,
1264 int __user
*stat_addr
, struct rusage __user
*ru
)
1266 unsigned long state
;
1267 int retval
, status
, traced
;
1268 pid_t pid
= task_pid_vnr(p
);
1270 if (!likely(options
& WEXITED
))
1273 if (unlikely(options
& WNOWAIT
)) {
1275 int exit_code
= p
->exit_code
;
1279 read_unlock(&tasklist_lock
);
1280 if ((exit_code
& 0x7f) == 0) {
1282 status
= exit_code
>> 8;
1284 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1285 status
= exit_code
& 0x7f;
1287 return wait_noreap_copyout(p
, pid
, uid
, why
,
1292 * Try to move the task's state to DEAD
1293 * only one thread is allowed to do this:
1295 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1296 if (state
!= EXIT_ZOMBIE
) {
1297 BUG_ON(state
!= EXIT_DEAD
);
1301 traced
= ptrace_reparented(p
);
1303 if (likely(!traced
)) {
1304 struct signal_struct
*psig
;
1305 struct signal_struct
*sig
;
1308 * The resource counters for the group leader are in its
1309 * own task_struct. Those for dead threads in the group
1310 * are in its signal_struct, as are those for the child
1311 * processes it has previously reaped. All these
1312 * accumulate in the parent's signal_struct c* fields.
1314 * We don't bother to take a lock here to protect these
1315 * p->signal fields, because they are only touched by
1316 * __exit_signal, which runs with tasklist_lock
1317 * write-locked anyway, and so is excluded here. We do
1318 * need to protect the access to p->parent->signal fields,
1319 * as other threads in the parent group can be right
1320 * here reaping other children at the same time.
1322 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1323 psig
= p
->parent
->signal
;
1326 cputime_add(psig
->cutime
,
1327 cputime_add(p
->utime
,
1328 cputime_add(sig
->utime
,
1331 cputime_add(psig
->cstime
,
1332 cputime_add(p
->stime
,
1333 cputime_add(sig
->stime
,
1336 cputime_add(psig
->cgtime
,
1337 cputime_add(p
->gtime
,
1338 cputime_add(sig
->gtime
,
1341 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1343 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1345 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1347 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1349 task_io_get_inblock(p
) +
1350 sig
->inblock
+ sig
->cinblock
;
1352 task_io_get_oublock(p
) +
1353 sig
->oublock
+ sig
->coublock
;
1354 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1358 * Now we are sure this task is interesting, and no other
1359 * thread can reap it because we set its state to EXIT_DEAD.
1361 read_unlock(&tasklist_lock
);
1363 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1364 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1365 ? p
->signal
->group_exit_code
: p
->exit_code
;
1366 if (!retval
&& stat_addr
)
1367 retval
= put_user(status
, stat_addr
);
1368 if (!retval
&& infop
)
1369 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1370 if (!retval
&& infop
)
1371 retval
= put_user(0, &infop
->si_errno
);
1372 if (!retval
&& infop
) {
1375 if ((status
& 0x7f) == 0) {
1379 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1382 retval
= put_user((short)why
, &infop
->si_code
);
1384 retval
= put_user(status
, &infop
->si_status
);
1386 if (!retval
&& infop
)
1387 retval
= put_user(pid
, &infop
->si_pid
);
1388 if (!retval
&& infop
)
1389 retval
= put_user(p
->uid
, &infop
->si_uid
);
1394 write_lock_irq(&tasklist_lock
);
1395 /* We dropped tasklist, ptracer could die and untrace */
1398 * If this is not a detached task, notify the parent.
1399 * If it's still not detached after that, don't release
1402 if (!task_detached(p
)) {
1403 do_notify_parent(p
, p
->exit_signal
);
1404 if (!task_detached(p
)) {
1405 p
->exit_state
= EXIT_ZOMBIE
;
1409 write_unlock_irq(&tasklist_lock
);
1418 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1419 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1420 * the lock and this task is uninteresting. If we return nonzero, we have
1421 * released the lock and the system call should return.
1423 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1424 int options
, struct siginfo __user
*infop
,
1425 int __user
*stat_addr
, struct rusage __user
*ru
)
1427 int retval
, exit_code
, why
;
1428 uid_t uid
= 0; /* unneeded, required by compiler */
1431 if (!(options
& WUNTRACED
))
1435 spin_lock_irq(&p
->sighand
->siglock
);
1437 if (unlikely(!task_is_stopped_or_traced(p
)))
1440 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1442 * A group stop is in progress and this is the group leader.
1443 * We won't report until all threads have stopped.
1447 exit_code
= p
->exit_code
;
1451 if (!unlikely(options
& WNOWAIT
))
1456 spin_unlock_irq(&p
->sighand
->siglock
);
1461 * Now we are pretty sure this task is interesting.
1462 * Make sure it doesn't get reaped out from under us while we
1463 * give up the lock and then examine it below. We don't want to
1464 * keep holding onto the tasklist_lock while we call getrusage and
1465 * possibly take page faults for user memory.
1468 pid
= task_pid_vnr(p
);
1469 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1470 read_unlock(&tasklist_lock
);
1472 if (unlikely(options
& WNOWAIT
))
1473 return wait_noreap_copyout(p
, pid
, uid
,
1477 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1478 if (!retval
&& stat_addr
)
1479 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1480 if (!retval
&& infop
)
1481 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1482 if (!retval
&& infop
)
1483 retval
= put_user(0, &infop
->si_errno
);
1484 if (!retval
&& infop
)
1485 retval
= put_user((short)why
, &infop
->si_code
);
1486 if (!retval
&& infop
)
1487 retval
= put_user(exit_code
, &infop
->si_status
);
1488 if (!retval
&& infop
)
1489 retval
= put_user(pid
, &infop
->si_pid
);
1490 if (!retval
&& infop
)
1491 retval
= put_user(uid
, &infop
->si_uid
);
1501 * Handle do_wait work for one task in a live, non-stopped state.
1502 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1503 * the lock and this task is uninteresting. If we return nonzero, we have
1504 * released the lock and the system call should return.
1506 static int wait_task_continued(struct task_struct
*p
, int options
,
1507 struct siginfo __user
*infop
,
1508 int __user
*stat_addr
, struct rusage __user
*ru
)
1514 if (!unlikely(options
& WCONTINUED
))
1517 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1520 spin_lock_irq(&p
->sighand
->siglock
);
1521 /* Re-check with the lock held. */
1522 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1523 spin_unlock_irq(&p
->sighand
->siglock
);
1526 if (!unlikely(options
& WNOWAIT
))
1527 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1528 spin_unlock_irq(&p
->sighand
->siglock
);
1530 pid
= task_pid_vnr(p
);
1533 read_unlock(&tasklist_lock
);
1536 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1538 if (!retval
&& stat_addr
)
1539 retval
= put_user(0xffff, stat_addr
);
1543 retval
= wait_noreap_copyout(p
, pid
, uid
,
1544 CLD_CONTINUED
, SIGCONT
,
1546 BUG_ON(retval
== 0);
1553 * Consider @p for a wait by @parent.
1555 * -ECHILD should be in *@notask_error before the first call.
1556 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1557 * Returns zero if the search for a child should continue;
1558 * then *@notask_error is 0 if @p is an eligible child,
1559 * or another error from security_task_wait(), or still -ECHILD.
1561 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1562 struct task_struct
*p
, int *notask_error
,
1563 enum pid_type type
, struct pid
*pid
, int options
,
1564 struct siginfo __user
*infop
,
1565 int __user
*stat_addr
, struct rusage __user
*ru
)
1567 int ret
= eligible_child(type
, pid
, options
, p
);
1571 if (unlikely(ret
< 0)) {
1573 * If we have not yet seen any eligible child,
1574 * then let this error code replace -ECHILD.
1575 * A permission error will give the user a clue
1576 * to look for security policy problems, rather
1577 * than for mysterious wait bugs.
1580 *notask_error
= ret
;
1583 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1585 * This child is hidden by ptrace.
1586 * We aren't allowed to see it now, but eventually we will.
1592 if (p
->exit_state
== EXIT_DEAD
)
1596 * We don't reap group leaders with subthreads.
1598 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1599 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1602 * It's stopped or running now, so it might
1603 * later continue, exit, or stop again.
1607 if (task_is_stopped_or_traced(p
))
1608 return wait_task_stopped(ptrace
, p
, options
,
1609 infop
, stat_addr
, ru
);
1611 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1615 * Do the work of do_wait() for one thread in the group, @tsk.
1617 * -ECHILD should be in *@notask_error before the first call.
1618 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1619 * Returns zero if the search for a child should continue; then
1620 * *@notask_error is 0 if there were any eligible children,
1621 * or another error from security_task_wait(), or still -ECHILD.
1623 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1624 enum pid_type type
, struct pid
*pid
, int options
,
1625 struct siginfo __user
*infop
, int __user
*stat_addr
,
1626 struct rusage __user
*ru
)
1628 struct task_struct
*p
;
1630 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1632 * Do not consider detached threads.
1634 if (!task_detached(p
)) {
1635 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1637 infop
, stat_addr
, ru
);
1646 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1647 enum pid_type type
, struct pid
*pid
, int options
,
1648 struct siginfo __user
*infop
, int __user
*stat_addr
,
1649 struct rusage __user
*ru
)
1651 struct task_struct
*p
;
1654 * Traditionally we see ptrace'd stopped tasks regardless of options.
1656 options
|= WUNTRACED
;
1658 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1659 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1661 infop
, stat_addr
, ru
);
1669 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1670 struct siginfo __user
*infop
, int __user
*stat_addr
,
1671 struct rusage __user
*ru
)
1673 DECLARE_WAITQUEUE(wait
, current
);
1674 struct task_struct
*tsk
;
1677 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1680 * If there is nothing that can match our critiera just get out.
1681 * We will clear @retval to zero if we see any child that might later
1682 * match our criteria, even if we are not able to reap it yet.
1685 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1688 current
->state
= TASK_INTERRUPTIBLE
;
1689 read_lock(&tasklist_lock
);
1692 int tsk_result
= do_wait_thread(tsk
, &retval
,
1694 infop
, stat_addr
, ru
);
1696 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1698 infop
, stat_addr
, ru
);
1701 * tasklist_lock is unlocked and we have a final result.
1703 retval
= tsk_result
;
1707 if (options
& __WNOTHREAD
)
1709 tsk
= next_thread(tsk
);
1710 BUG_ON(tsk
->signal
!= current
->signal
);
1711 } while (tsk
!= current
);
1712 read_unlock(&tasklist_lock
);
1714 if (!retval
&& !(options
& WNOHANG
)) {
1715 retval
= -ERESTARTSYS
;
1716 if (!signal_pending(current
)) {
1723 current
->state
= TASK_RUNNING
;
1724 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1730 * For a WNOHANG return, clear out all the fields
1731 * we would set so the user can easily tell the
1735 retval
= put_user(0, &infop
->si_signo
);
1737 retval
= put_user(0, &infop
->si_errno
);
1739 retval
= put_user(0, &infop
->si_code
);
1741 retval
= put_user(0, &infop
->si_pid
);
1743 retval
= put_user(0, &infop
->si_uid
);
1745 retval
= put_user(0, &infop
->si_status
);
1751 asmlinkage
long sys_waitid(int which
, pid_t upid
,
1752 struct siginfo __user
*infop
, int options
,
1753 struct rusage __user
*ru
)
1755 struct pid
*pid
= NULL
;
1759 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1761 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1774 type
= PIDTYPE_PGID
;
1782 if (type
< PIDTYPE_MAX
)
1783 pid
= find_get_pid(upid
);
1784 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1787 /* avoid REGPARM breakage on x86: */
1788 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1792 asmlinkage
long sys_wait4(pid_t upid
, int __user
*stat_addr
,
1793 int options
, struct rusage __user
*ru
)
1795 struct pid
*pid
= NULL
;
1799 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1800 __WNOTHREAD
|__WCLONE
|__WALL
))
1805 else if (upid
< 0) {
1806 type
= PIDTYPE_PGID
;
1807 pid
= find_get_pid(-upid
);
1808 } else if (upid
== 0) {
1809 type
= PIDTYPE_PGID
;
1810 pid
= get_pid(task_pgrp(current
));
1811 } else /* upid > 0 */ {
1813 pid
= find_get_pid(upid
);
1816 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1819 /* avoid REGPARM breakage on x86: */
1820 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1824 #ifdef __ARCH_WANT_SYS_WAITPID
1827 * sys_waitpid() remains for compatibility. waitpid() should be
1828 * implemented by calling sys_wait4() from libc.a.
1830 asmlinkage
long sys_waitpid(pid_t pid
, int __user
*stat_addr
, int options
)
1832 return sys_wait4(pid
, stat_addr
, options
, NULL
);