]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - kernel/exit.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/capability.h>
12 #include <linux/completion.h>
13 #include <linux/personality.h>
14 #include <linux/tty.h>
15 #include <linux/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 <linux/fs_struct.h>
50 #include <linux/init_task.h>
51 #include <trace/sched.h>
53 #include <asm/uaccess.h>
54 #include <asm/unistd.h>
55 #include <asm/pgtable.h>
56 #include <asm/mmu_context.h>
57 #include "cred-internals.h"
59 DEFINE_TRACE(sched_process_free
);
60 DEFINE_TRACE(sched_process_exit
);
61 DEFINE_TRACE(sched_process_wait
);
63 static void exit_mm(struct task_struct
* tsk
);
65 static inline int task_detached(struct task_struct
*p
)
67 return p
->exit_signal
== -1;
70 static void __unhash_process(struct task_struct
*p
)
73 detach_pid(p
, PIDTYPE_PID
);
74 if (thread_group_leader(p
)) {
75 detach_pid(p
, PIDTYPE_PGID
);
76 detach_pid(p
, PIDTYPE_SID
);
78 list_del_rcu(&p
->tasks
);
79 __get_cpu_var(process_counts
)--;
81 list_del_rcu(&p
->thread_group
);
82 list_del_init(&p
->sibling
);
86 * This function expects the tasklist_lock write-locked.
88 static void __exit_signal(struct task_struct
*tsk
)
90 struct signal_struct
*sig
= tsk
->signal
;
91 struct sighand_struct
*sighand
;
94 BUG_ON(!atomic_read(&sig
->count
));
96 sighand
= rcu_dereference(tsk
->sighand
);
97 spin_lock(&sighand
->siglock
);
99 posix_cpu_timers_exit(tsk
);
100 if (atomic_dec_and_test(&sig
->count
))
101 posix_cpu_timers_exit_group(tsk
);
104 * If there is any task waiting for the group exit
107 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
108 wake_up_process(sig
->group_exit_task
);
110 if (tsk
== sig
->curr_target
)
111 sig
->curr_target
= next_thread(tsk
);
113 * Accumulate here the counters for all threads but the
114 * group leader as they die, so they can be added into
115 * the process-wide totals when those are taken.
116 * The group leader stays around as a zombie as long
117 * as there are other threads. When it gets reaped,
118 * the exit.c code will add its counts into these totals.
119 * We won't ever get here for the group leader, since it
120 * will have been the last reference on the signal_struct.
122 sig
->utime
= cputime_add(sig
->utime
, task_utime(tsk
));
123 sig
->stime
= cputime_add(sig
->stime
, task_stime(tsk
));
124 sig
->gtime
= cputime_add(sig
->gtime
, task_gtime(tsk
));
125 sig
->min_flt
+= tsk
->min_flt
;
126 sig
->maj_flt
+= tsk
->maj_flt
;
127 sig
->nvcsw
+= tsk
->nvcsw
;
128 sig
->nivcsw
+= tsk
->nivcsw
;
129 sig
->inblock
+= task_io_get_inblock(tsk
);
130 sig
->oublock
+= task_io_get_oublock(tsk
);
131 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
132 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
133 sig
= NULL
; /* Marker for below. */
136 __unhash_process(tsk
);
139 * Do this under ->siglock, we can race with another thread
140 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
142 flush_sigqueue(&tsk
->pending
);
146 spin_unlock(&sighand
->siglock
);
148 __cleanup_sighand(sighand
);
149 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
151 flush_sigqueue(&sig
->shared_pending
);
152 taskstats_tgid_free(sig
);
154 * Make sure ->signal can't go away under rq->lock,
155 * see account_group_exec_runtime().
157 task_rq_unlock_wait(tsk
);
158 __cleanup_signal(sig
);
162 static void delayed_put_task_struct(struct rcu_head
*rhp
)
164 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
166 trace_sched_process_free(tsk
);
167 put_task_struct(tsk
);
171 void release_task(struct task_struct
* p
)
173 struct task_struct
*leader
;
176 tracehook_prepare_release_task(p
);
177 /* don't need to get the RCU readlock here - the process is dead and
178 * can't be modifying its own credentials */
179 atomic_dec(&__task_cred(p
)->user
->processes
);
182 write_lock_irq(&tasklist_lock
);
183 tracehook_finish_release_task(p
);
187 * If we are the last non-leader member of the thread
188 * group, and the leader is zombie, then notify the
189 * group leader's parent process. (if it wants notification.)
192 leader
= p
->group_leader
;
193 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
194 BUG_ON(task_detached(leader
));
195 do_notify_parent(leader
, leader
->exit_signal
);
197 * If we were the last child thread and the leader has
198 * exited already, and the leader's parent ignores SIGCHLD,
199 * then we are the one who should release the leader.
201 * do_notify_parent() will have marked it self-reaping in
204 zap_leader
= task_detached(leader
);
207 * This maintains the invariant that release_task()
208 * only runs on a task in EXIT_DEAD, just for sanity.
211 leader
->exit_state
= EXIT_DEAD
;
214 write_unlock_irq(&tasklist_lock
);
216 call_rcu(&p
->rcu
, delayed_put_task_struct
);
219 if (unlikely(zap_leader
))
224 * This checks not only the pgrp, but falls back on the pid if no
225 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
228 * The caller must hold rcu lock or the tasklist lock.
230 struct pid
*session_of_pgrp(struct pid
*pgrp
)
232 struct task_struct
*p
;
233 struct pid
*sid
= NULL
;
235 p
= pid_task(pgrp
, PIDTYPE_PGID
);
237 p
= pid_task(pgrp
, PIDTYPE_PID
);
239 sid
= task_session(p
);
245 * Determine if a process group is "orphaned", according to the POSIX
246 * definition in 2.2.2.52. Orphaned process groups are not to be affected
247 * by terminal-generated stop signals. Newly orphaned process groups are
248 * to receive a SIGHUP and a SIGCONT.
250 * "I ask you, have you ever known what it is to be an orphan?"
252 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
254 struct task_struct
*p
;
256 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
257 if ((p
== ignored_task
) ||
258 (p
->exit_state
&& thread_group_empty(p
)) ||
259 is_global_init(p
->real_parent
))
262 if (task_pgrp(p
->real_parent
) != pgrp
&&
263 task_session(p
->real_parent
) == task_session(p
))
265 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
270 int is_current_pgrp_orphaned(void)
274 read_lock(&tasklist_lock
);
275 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
276 read_unlock(&tasklist_lock
);
281 static int has_stopped_jobs(struct pid
*pgrp
)
284 struct task_struct
*p
;
286 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
287 if (!task_is_stopped(p
))
291 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
296 * Check to see if any process groups have become orphaned as
297 * a result of our exiting, and if they have any stopped jobs,
298 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
301 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
303 struct pid
*pgrp
= task_pgrp(tsk
);
304 struct task_struct
*ignored_task
= tsk
;
307 /* exit: our father is in a different pgrp than
308 * we are and we were the only connection outside.
310 parent
= tsk
->real_parent
;
312 /* reparent: our child is in a different pgrp than
313 * we are, and it was the only connection outside.
317 if (task_pgrp(parent
) != pgrp
&&
318 task_session(parent
) == task_session(tsk
) &&
319 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
320 has_stopped_jobs(pgrp
)) {
321 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
322 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
327 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
329 * If a kernel thread is launched as a result of a system call, or if
330 * it ever exits, it should generally reparent itself to kthreadd so it
331 * isn't in the way of other processes and is correctly cleaned up on exit.
333 * The various task state such as scheduling policy and priority may have
334 * been inherited from a user process, so we reset them to sane values here.
336 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
338 static void reparent_to_kthreadd(void)
340 write_lock_irq(&tasklist_lock
);
342 ptrace_unlink(current
);
343 /* Reparent to init */
344 current
->real_parent
= current
->parent
= kthreadd_task
;
345 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
347 /* Set the exit signal to SIGCHLD so we signal init on exit */
348 current
->exit_signal
= SIGCHLD
;
350 if (task_nice(current
) < 0)
351 set_user_nice(current
, 0);
355 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
356 sizeof(current
->signal
->rlim
));
358 atomic_inc(&init_cred
.usage
);
359 commit_creds(&init_cred
);
360 write_unlock_irq(&tasklist_lock
);
363 void __set_special_pids(struct pid
*pid
)
365 struct task_struct
*curr
= current
->group_leader
;
366 pid_t nr
= pid_nr(pid
);
368 if (task_session(curr
) != pid
) {
369 change_pid(curr
, PIDTYPE_SID
, pid
);
370 set_task_session(curr
, nr
);
372 if (task_pgrp(curr
) != pid
) {
373 change_pid(curr
, PIDTYPE_PGID
, pid
);
374 set_task_pgrp(curr
, nr
);
378 static void set_special_pids(struct pid
*pid
)
380 write_lock_irq(&tasklist_lock
);
381 __set_special_pids(pid
);
382 write_unlock_irq(&tasklist_lock
);
386 * Let kernel threads use this to say that they
387 * allow a certain signal (since daemonize() will
388 * have disabled all of them by default).
390 int allow_signal(int sig
)
392 if (!valid_signal(sig
) || sig
< 1)
395 spin_lock_irq(¤t
->sighand
->siglock
);
396 sigdelset(¤t
->blocked
, sig
);
398 /* Kernel threads handle their own signals.
399 Let the signal code know it'll be handled, so
400 that they don't get converted to SIGKILL or
401 just silently dropped */
402 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
405 spin_unlock_irq(¤t
->sighand
->siglock
);
409 EXPORT_SYMBOL(allow_signal
);
411 int disallow_signal(int sig
)
413 if (!valid_signal(sig
) || sig
< 1)
416 spin_lock_irq(¤t
->sighand
->siglock
);
417 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
419 spin_unlock_irq(¤t
->sighand
->siglock
);
423 EXPORT_SYMBOL(disallow_signal
);
426 * Put all the gunge required to become a kernel thread without
427 * attached user resources in one place where it belongs.
430 void daemonize(const char *name
, ...)
435 va_start(args
, name
);
436 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
440 * If we were started as result of loading a module, close all of the
441 * user space pages. We don't need them, and if we didn't close them
442 * they would be locked into memory.
446 * We don't want to have TIF_FREEZE set if the system-wide hibernation
447 * or suspend transition begins right now.
449 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
451 if (current
->nsproxy
!= &init_nsproxy
) {
452 get_nsproxy(&init_nsproxy
);
453 switch_task_namespaces(current
, &init_nsproxy
);
455 set_special_pids(&init_struct_pid
);
456 proc_clear_tty(current
);
458 /* Block and flush all signals */
459 sigfillset(&blocked
);
460 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
461 flush_signals(current
);
463 /* Become as one with the init task */
465 daemonize_fs_struct();
467 current
->files
= init_task
.files
;
468 atomic_inc(¤t
->files
->count
);
470 reparent_to_kthreadd();
473 EXPORT_SYMBOL(daemonize
);
475 static void close_files(struct files_struct
* files
)
483 * It is safe to dereference the fd table without RCU or
484 * ->file_lock because this is the last reference to the
487 fdt
= files_fdtable(files
);
491 if (i
>= fdt
->max_fds
)
493 set
= fdt
->open_fds
->fds_bits
[j
++];
496 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
498 filp_close(file
, files
);
508 struct files_struct
*get_files_struct(struct task_struct
*task
)
510 struct files_struct
*files
;
515 atomic_inc(&files
->count
);
521 void put_files_struct(struct files_struct
*files
)
525 if (atomic_dec_and_test(&files
->count
)) {
528 * Free the fd and fdset arrays if we expanded them.
529 * If the fdtable was embedded, pass files for freeing
530 * at the end of the RCU grace period. Otherwise,
531 * you can free files immediately.
533 fdt
= files_fdtable(files
);
534 if (fdt
!= &files
->fdtab
)
535 kmem_cache_free(files_cachep
, files
);
540 void reset_files_struct(struct files_struct
*files
)
542 struct task_struct
*tsk
= current
;
543 struct files_struct
*old
;
549 put_files_struct(old
);
552 void exit_files(struct task_struct
*tsk
)
554 struct files_struct
* files
= tsk
->files
;
560 put_files_struct(files
);
564 #ifdef CONFIG_MM_OWNER
566 * Task p is exiting and it owned mm, lets find a new owner for it
569 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
572 * If there are other users of the mm and the owner (us) is exiting
573 * we need to find a new owner to take on the responsibility.
575 if (atomic_read(&mm
->mm_users
) <= 1)
582 void mm_update_next_owner(struct mm_struct
*mm
)
584 struct task_struct
*c
, *g
, *p
= current
;
587 if (!mm_need_new_owner(mm
, p
))
590 read_lock(&tasklist_lock
);
592 * Search in the children
594 list_for_each_entry(c
, &p
->children
, sibling
) {
596 goto assign_new_owner
;
600 * Search in the siblings
602 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
604 goto assign_new_owner
;
608 * Search through everything else. We should not get
611 do_each_thread(g
, c
) {
613 goto assign_new_owner
;
614 } while_each_thread(g
, c
);
616 read_unlock(&tasklist_lock
);
618 * We found no owner yet mm_users > 1: this implies that we are
619 * most likely racing with swapoff (try_to_unuse()) or /proc or
620 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
629 * The task_lock protects c->mm from changing.
630 * We always want mm->owner->mm == mm
634 * Delay read_unlock() till we have the task_lock()
635 * to ensure that c does not slip away underneath us
637 read_unlock(&tasklist_lock
);
647 #endif /* CONFIG_MM_OWNER */
650 * Turn us into a lazy TLB process if we
653 static void exit_mm(struct task_struct
* tsk
)
655 struct mm_struct
*mm
= tsk
->mm
;
656 struct core_state
*core_state
;
662 * Serialize with any possible pending coredump.
663 * We must hold mmap_sem around checking core_state
664 * and clearing tsk->mm. The core-inducing thread
665 * will increment ->nr_threads for each thread in the
666 * group with ->mm != NULL.
668 down_read(&mm
->mmap_sem
);
669 core_state
= mm
->core_state
;
671 struct core_thread self
;
672 up_read(&mm
->mmap_sem
);
675 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
677 * Implies mb(), the result of xchg() must be visible
678 * to core_state->dumper.
680 if (atomic_dec_and_test(&core_state
->nr_threads
))
681 complete(&core_state
->startup
);
684 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
685 if (!self
.task
) /* see coredump_finish() */
689 __set_task_state(tsk
, TASK_RUNNING
);
690 down_read(&mm
->mmap_sem
);
692 atomic_inc(&mm
->mm_count
);
693 BUG_ON(mm
!= tsk
->active_mm
);
694 /* more a memory barrier than a real lock */
697 up_read(&mm
->mmap_sem
);
698 enter_lazy_tlb(mm
, current
);
699 /* We don't want this task to be frozen prematurely */
700 clear_freeze_flag(tsk
);
702 mm_update_next_owner(mm
);
707 * Return nonzero if @parent's children should reap themselves.
709 * Called with write_lock_irq(&tasklist_lock) held.
711 static int ignoring_children(struct task_struct
*parent
)
714 struct sighand_struct
*psig
= parent
->sighand
;
716 spin_lock_irqsave(&psig
->siglock
, flags
);
717 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
718 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
719 spin_unlock_irqrestore(&psig
->siglock
, flags
);
724 * Detach all tasks we were using ptrace on.
725 * Any that need to be release_task'd are put on the @dead list.
727 * Called with write_lock(&tasklist_lock) held.
729 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
731 struct task_struct
*p
, *n
;
734 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
737 if (p
->exit_state
!= EXIT_ZOMBIE
)
741 * If it's a zombie, our attachedness prevented normal
742 * parent notification or self-reaping. Do notification
743 * now if it would have happened earlier. If it should
744 * reap itself, add it to the @dead list. We can't call
745 * release_task() here because we already hold tasklist_lock.
747 * If it's our own child, there is no notification to do.
748 * But if our normal children self-reap, then this child
749 * was prevented by ptrace and we must reap it now.
751 if (!task_detached(p
) && thread_group_empty(p
)) {
752 if (!same_thread_group(p
->real_parent
, parent
))
753 do_notify_parent(p
, p
->exit_signal
);
756 ign
= ignoring_children(parent
);
762 if (task_detached(p
)) {
764 * Mark it as in the process of being reaped.
766 p
->exit_state
= EXIT_DEAD
;
767 list_add(&p
->ptrace_entry
, dead
);
773 * Finish up exit-time ptrace cleanup.
775 * Called without locks.
777 static void ptrace_exit_finish(struct task_struct
*parent
,
778 struct list_head
*dead
)
780 struct task_struct
*p
, *n
;
782 BUG_ON(!list_empty(&parent
->ptraced
));
784 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
785 list_del_init(&p
->ptrace_entry
);
790 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
792 if (p
->pdeath_signal
)
793 /* We already hold the tasklist_lock here. */
794 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
796 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
798 /* If this is a threaded reparent there is no need to
799 * notify anyone anything has happened.
801 if (same_thread_group(p
->real_parent
, father
))
804 /* We don't want people slaying init. */
805 if (!task_detached(p
))
806 p
->exit_signal
= SIGCHLD
;
808 /* If we'd notified the old parent about this child's death,
809 * also notify the new parent.
811 if (!ptrace_reparented(p
) &&
812 p
->exit_state
== EXIT_ZOMBIE
&&
813 !task_detached(p
) && thread_group_empty(p
))
814 do_notify_parent(p
, p
->exit_signal
);
816 kill_orphaned_pgrp(p
, father
);
820 * When we die, we re-parent all our children.
821 * Try to give them to another thread in our thread
822 * group, and if no such member exists, give it to
823 * the child reaper process (ie "init") in our pid
826 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
828 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
829 struct task_struct
*thread
;
832 while_each_thread(father
, thread
) {
833 if (thread
->flags
& PF_EXITING
)
835 if (unlikely(pid_ns
->child_reaper
== father
))
836 pid_ns
->child_reaper
= thread
;
840 if (unlikely(pid_ns
->child_reaper
== father
)) {
841 write_unlock_irq(&tasklist_lock
);
842 if (unlikely(pid_ns
== &init_pid_ns
))
843 panic("Attempted to kill init!");
845 zap_pid_ns_processes(pid_ns
);
846 write_lock_irq(&tasklist_lock
);
848 * We can not clear ->child_reaper or leave it alone.
849 * There may by stealth EXIT_DEAD tasks on ->children,
850 * forget_original_parent() must move them somewhere.
852 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
855 return pid_ns
->child_reaper
;
858 static void forget_original_parent(struct task_struct
*father
)
860 struct task_struct
*p
, *n
, *reaper
;
861 LIST_HEAD(ptrace_dead
);
863 write_lock_irq(&tasklist_lock
);
864 reaper
= find_new_reaper(father
);
866 * First clean up ptrace if we were using it.
868 ptrace_exit(father
, &ptrace_dead
);
870 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
871 p
->real_parent
= reaper
;
872 if (p
->parent
== father
) {
874 p
->parent
= p
->real_parent
;
876 reparent_thread(p
, father
);
879 write_unlock_irq(&tasklist_lock
);
880 BUG_ON(!list_empty(&father
->children
));
882 ptrace_exit_finish(father
, &ptrace_dead
);
886 * Send signals to all our closest relatives so that they know
887 * to properly mourn us..
889 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
895 * This does two things:
897 * A. Make init inherit all the child processes
898 * B. Check to see if any process groups have become orphaned
899 * as a result of our exiting, and if they have any stopped
900 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
902 forget_original_parent(tsk
);
903 exit_task_namespaces(tsk
);
905 write_lock_irq(&tasklist_lock
);
907 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
909 /* Let father know we died
911 * Thread signals are configurable, but you aren't going to use
912 * that to send signals to arbitary processes.
913 * That stops right now.
915 * If the parent exec id doesn't match the exec id we saved
916 * when we started then we know the parent has changed security
919 * If our self_exec id doesn't match our parent_exec_id then
920 * we have changed execution domain as these two values started
921 * the same after a fork.
923 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
924 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
925 tsk
->self_exec_id
!= tsk
->parent_exec_id
) &&
927 tsk
->exit_signal
= SIGCHLD
;
929 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
931 signal
= do_notify_parent(tsk
, signal
);
933 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
935 /* mt-exec, de_thread() is waiting for us */
936 if (thread_group_leader(tsk
) &&
937 tsk
->signal
->group_exit_task
&&
938 tsk
->signal
->notify_count
< 0)
939 wake_up_process(tsk
->signal
->group_exit_task
);
941 write_unlock_irq(&tasklist_lock
);
943 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
945 /* If the process is dead, release it - nobody will wait for it */
946 if (signal
== DEATH_REAP
)
950 #ifdef CONFIG_DEBUG_STACK_USAGE
951 static void check_stack_usage(void)
953 static DEFINE_SPINLOCK(low_water_lock
);
954 static int lowest_to_date
= THREAD_SIZE
;
957 free
= stack_not_used(current
);
959 if (free
>= lowest_to_date
)
962 spin_lock(&low_water_lock
);
963 if (free
< lowest_to_date
) {
964 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
966 current
->comm
, free
);
967 lowest_to_date
= free
;
969 spin_unlock(&low_water_lock
);
972 static inline void check_stack_usage(void) {}
975 NORET_TYPE
void do_exit(long code
)
977 struct task_struct
*tsk
= current
;
980 profile_task_exit(tsk
);
982 WARN_ON(atomic_read(&tsk
->fs_excl
));
984 if (unlikely(in_interrupt()))
985 panic("Aiee, killing interrupt handler!");
986 if (unlikely(!tsk
->pid
))
987 panic("Attempted to kill the idle task!");
989 tracehook_report_exit(&code
);
992 * We're taking recursive faults here in do_exit. Safest is to just
993 * leave this task alone and wait for reboot.
995 if (unlikely(tsk
->flags
& PF_EXITING
)) {
997 "Fixing recursive fault but reboot is needed!\n");
999 * We can do this unlocked here. The futex code uses
1000 * this flag just to verify whether the pi state
1001 * cleanup has been done or not. In the worst case it
1002 * loops once more. We pretend that the cleanup was
1003 * done as there is no way to return. Either the
1004 * OWNER_DIED bit is set by now or we push the blocked
1005 * task into the wait for ever nirwana as well.
1007 tsk
->flags
|= PF_EXITPIDONE
;
1008 set_current_state(TASK_UNINTERRUPTIBLE
);
1012 exit_signals(tsk
); /* sets PF_EXITING */
1014 * tsk->flags are checked in the futex code to protect against
1015 * an exiting task cleaning up the robust pi futexes.
1018 spin_unlock_wait(&tsk
->pi_lock
);
1020 if (unlikely(in_atomic()))
1021 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1022 current
->comm
, task_pid_nr(current
),
1025 acct_update_integrals(tsk
);
1027 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1029 hrtimer_cancel(&tsk
->signal
->real_timer
);
1030 exit_itimers(tsk
->signal
);
1032 acct_collect(code
, group_dead
);
1035 if (unlikely(tsk
->audit_context
))
1038 tsk
->exit_code
= code
;
1039 taskstats_exit(tsk
, group_dead
);
1045 trace_sched_process_exit(tsk
);
1050 check_stack_usage();
1052 cgroup_exit(tsk
, 1);
1054 if (group_dead
&& tsk
->signal
->leader
)
1055 disassociate_ctty(1);
1057 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1059 module_put(tsk
->binfmt
->module
);
1061 proc_exit_connector(tsk
);
1062 exit_notify(tsk
, group_dead
);
1064 mpol_put(tsk
->mempolicy
);
1065 tsk
->mempolicy
= NULL
;
1069 * This must happen late, after the PID is not
1072 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1073 exit_pi_state_list(tsk
);
1074 if (unlikely(current
->pi_state_cache
))
1075 kfree(current
->pi_state_cache
);
1078 * Make sure we are holding no locks:
1080 debug_check_no_locks_held(tsk
);
1082 * We can do this unlocked here. The futex code uses this flag
1083 * just to verify whether the pi state cleanup has been done
1084 * or not. In the worst case it loops once more.
1086 tsk
->flags
|= PF_EXITPIDONE
;
1088 if (tsk
->io_context
)
1091 if (tsk
->splice_pipe
)
1092 __free_pipe_info(tsk
->splice_pipe
);
1095 /* causes final put_task_struct in finish_task_switch(). */
1096 tsk
->state
= TASK_DEAD
;
1099 /* Avoid "noreturn function does return". */
1101 cpu_relax(); /* For when BUG is null */
1104 EXPORT_SYMBOL_GPL(do_exit
);
1106 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1114 EXPORT_SYMBOL(complete_and_exit
);
1116 SYSCALL_DEFINE1(exit
, int, error_code
)
1118 do_exit((error_code
&0xff)<<8);
1122 * Take down every thread in the group. This is called by fatal signals
1123 * as well as by sys_exit_group (below).
1126 do_group_exit(int exit_code
)
1128 struct signal_struct
*sig
= current
->signal
;
1130 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1132 if (signal_group_exit(sig
))
1133 exit_code
= sig
->group_exit_code
;
1134 else if (!thread_group_empty(current
)) {
1135 struct sighand_struct
*const sighand
= current
->sighand
;
1136 spin_lock_irq(&sighand
->siglock
);
1137 if (signal_group_exit(sig
))
1138 /* Another thread got here before we took the lock. */
1139 exit_code
= sig
->group_exit_code
;
1141 sig
->group_exit_code
= exit_code
;
1142 sig
->flags
= SIGNAL_GROUP_EXIT
;
1143 zap_other_threads(current
);
1145 spin_unlock_irq(&sighand
->siglock
);
1153 * this kills every thread in the thread group. Note that any externally
1154 * wait4()-ing process will get the correct exit code - even if this
1155 * thread is not the thread group leader.
1157 SYSCALL_DEFINE1(exit_group
, int, error_code
)
1159 do_group_exit((error_code
& 0xff) << 8);
1164 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1166 struct pid
*pid
= NULL
;
1167 if (type
== PIDTYPE_PID
)
1168 pid
= task
->pids
[type
].pid
;
1169 else if (type
< PIDTYPE_MAX
)
1170 pid
= task
->group_leader
->pids
[type
].pid
;
1174 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1175 struct task_struct
*p
)
1179 if (type
< PIDTYPE_MAX
) {
1180 if (task_pid_type(p
, type
) != pid
)
1184 /* Wait for all children (clone and not) if __WALL is set;
1185 * otherwise, wait for clone children *only* if __WCLONE is
1186 * set; otherwise, wait for non-clone children *only*. (Note:
1187 * A "clone" child here is one that reports to its parent
1188 * using a signal other than SIGCHLD.) */
1189 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1190 && !(options
& __WALL
))
1193 err
= security_task_wait(p
);
1200 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1201 int why
, int status
,
1202 struct siginfo __user
*infop
,
1203 struct rusage __user
*rusagep
)
1205 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1209 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1211 retval
= put_user(0, &infop
->si_errno
);
1213 retval
= put_user((short)why
, &infop
->si_code
);
1215 retval
= put_user(pid
, &infop
->si_pid
);
1217 retval
= put_user(uid
, &infop
->si_uid
);
1219 retval
= put_user(status
, &infop
->si_status
);
1226 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1227 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1228 * the lock and this task is uninteresting. If we return nonzero, we have
1229 * released the lock and the system call should return.
1231 static int wait_task_zombie(struct task_struct
*p
, int options
,
1232 struct siginfo __user
*infop
,
1233 int __user
*stat_addr
, struct rusage __user
*ru
)
1235 unsigned long state
;
1236 int retval
, status
, traced
;
1237 pid_t pid
= task_pid_vnr(p
);
1238 uid_t uid
= __task_cred(p
)->uid
;
1240 if (!likely(options
& WEXITED
))
1243 if (unlikely(options
& WNOWAIT
)) {
1244 int exit_code
= p
->exit_code
;
1248 read_unlock(&tasklist_lock
);
1249 if ((exit_code
& 0x7f) == 0) {
1251 status
= exit_code
>> 8;
1253 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1254 status
= exit_code
& 0x7f;
1256 return wait_noreap_copyout(p
, pid
, uid
, why
,
1261 * Try to move the task's state to DEAD
1262 * only one thread is allowed to do this:
1264 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1265 if (state
!= EXIT_ZOMBIE
) {
1266 BUG_ON(state
!= EXIT_DEAD
);
1270 traced
= ptrace_reparented(p
);
1272 if (likely(!traced
)) {
1273 struct signal_struct
*psig
;
1274 struct signal_struct
*sig
;
1275 struct task_cputime cputime
;
1278 * The resource counters for the group leader are in its
1279 * own task_struct. Those for dead threads in the group
1280 * are in its signal_struct, as are those for the child
1281 * processes it has previously reaped. All these
1282 * accumulate in the parent's signal_struct c* fields.
1284 * We don't bother to take a lock here to protect these
1285 * p->signal fields, because they are only touched by
1286 * __exit_signal, which runs with tasklist_lock
1287 * write-locked anyway, and so is excluded here. We do
1288 * need to protect the access to p->parent->signal fields,
1289 * as other threads in the parent group can be right
1290 * here reaping other children at the same time.
1292 * We use thread_group_cputime() to get times for the thread
1293 * group, which consolidates times for all threads in the
1294 * group including the group leader.
1296 thread_group_cputime(p
, &cputime
);
1297 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1298 psig
= p
->parent
->signal
;
1301 cputime_add(psig
->cutime
,
1302 cputime_add(cputime
.utime
,
1305 cputime_add(psig
->cstime
,
1306 cputime_add(cputime
.stime
,
1309 cputime_add(psig
->cgtime
,
1310 cputime_add(p
->gtime
,
1311 cputime_add(sig
->gtime
,
1314 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1316 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1318 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1320 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1322 task_io_get_inblock(p
) +
1323 sig
->inblock
+ sig
->cinblock
;
1325 task_io_get_oublock(p
) +
1326 sig
->oublock
+ sig
->coublock
;
1327 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1328 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1329 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1333 * Now we are sure this task is interesting, and no other
1334 * thread can reap it because we set its state to EXIT_DEAD.
1336 read_unlock(&tasklist_lock
);
1338 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1339 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1340 ? p
->signal
->group_exit_code
: p
->exit_code
;
1341 if (!retval
&& stat_addr
)
1342 retval
= put_user(status
, stat_addr
);
1343 if (!retval
&& infop
)
1344 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1345 if (!retval
&& infop
)
1346 retval
= put_user(0, &infop
->si_errno
);
1347 if (!retval
&& infop
) {
1350 if ((status
& 0x7f) == 0) {
1354 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1357 retval
= put_user((short)why
, &infop
->si_code
);
1359 retval
= put_user(status
, &infop
->si_status
);
1361 if (!retval
&& infop
)
1362 retval
= put_user(pid
, &infop
->si_pid
);
1363 if (!retval
&& infop
)
1364 retval
= put_user(uid
, &infop
->si_uid
);
1369 write_lock_irq(&tasklist_lock
);
1370 /* We dropped tasklist, ptracer could die and untrace */
1373 * If this is not a detached task, notify the parent.
1374 * If it's still not detached after that, don't release
1377 if (!task_detached(p
)) {
1378 do_notify_parent(p
, p
->exit_signal
);
1379 if (!task_detached(p
)) {
1380 p
->exit_state
= EXIT_ZOMBIE
;
1384 write_unlock_irq(&tasklist_lock
);
1393 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1394 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1395 * the lock and this task is uninteresting. If we return nonzero, we have
1396 * released the lock and the system call should return.
1398 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1399 int options
, struct siginfo __user
*infop
,
1400 int __user
*stat_addr
, struct rusage __user
*ru
)
1402 int retval
, exit_code
, why
;
1403 uid_t uid
= 0; /* unneeded, required by compiler */
1406 if (!(options
& WUNTRACED
))
1410 spin_lock_irq(&p
->sighand
->siglock
);
1412 if (unlikely(!task_is_stopped_or_traced(p
)))
1415 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1417 * A group stop is in progress and this is the group leader.
1418 * We won't report until all threads have stopped.
1422 exit_code
= p
->exit_code
;
1426 if (!unlikely(options
& WNOWAIT
))
1429 /* don't need the RCU readlock here as we're holding a spinlock */
1430 uid
= __task_cred(p
)->uid
;
1432 spin_unlock_irq(&p
->sighand
->siglock
);
1437 * Now we are pretty sure this task is interesting.
1438 * Make sure it doesn't get reaped out from under us while we
1439 * give up the lock and then examine it below. We don't want to
1440 * keep holding onto the tasklist_lock while we call getrusage and
1441 * possibly take page faults for user memory.
1444 pid
= task_pid_vnr(p
);
1445 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1446 read_unlock(&tasklist_lock
);
1448 if (unlikely(options
& WNOWAIT
))
1449 return wait_noreap_copyout(p
, pid
, uid
,
1453 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1454 if (!retval
&& stat_addr
)
1455 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1456 if (!retval
&& infop
)
1457 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1458 if (!retval
&& infop
)
1459 retval
= put_user(0, &infop
->si_errno
);
1460 if (!retval
&& infop
)
1461 retval
= put_user((short)why
, &infop
->si_code
);
1462 if (!retval
&& infop
)
1463 retval
= put_user(exit_code
, &infop
->si_status
);
1464 if (!retval
&& infop
)
1465 retval
= put_user(pid
, &infop
->si_pid
);
1466 if (!retval
&& infop
)
1467 retval
= put_user(uid
, &infop
->si_uid
);
1477 * Handle do_wait work for one task in a live, non-stopped state.
1478 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1479 * the lock and this task is uninteresting. If we return nonzero, we have
1480 * released the lock and the system call should return.
1482 static int wait_task_continued(struct task_struct
*p
, int options
,
1483 struct siginfo __user
*infop
,
1484 int __user
*stat_addr
, struct rusage __user
*ru
)
1490 if (!unlikely(options
& WCONTINUED
))
1493 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1496 spin_lock_irq(&p
->sighand
->siglock
);
1497 /* Re-check with the lock held. */
1498 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1499 spin_unlock_irq(&p
->sighand
->siglock
);
1502 if (!unlikely(options
& WNOWAIT
))
1503 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1504 uid
= __task_cred(p
)->uid
;
1505 spin_unlock_irq(&p
->sighand
->siglock
);
1507 pid
= task_pid_vnr(p
);
1509 read_unlock(&tasklist_lock
);
1512 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1514 if (!retval
&& stat_addr
)
1515 retval
= put_user(0xffff, stat_addr
);
1519 retval
= wait_noreap_copyout(p
, pid
, uid
,
1520 CLD_CONTINUED
, SIGCONT
,
1522 BUG_ON(retval
== 0);
1529 * Consider @p for a wait by @parent.
1531 * -ECHILD should be in *@notask_error before the first call.
1532 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1533 * Returns zero if the search for a child should continue;
1534 * then *@notask_error is 0 if @p is an eligible child,
1535 * or another error from security_task_wait(), or still -ECHILD.
1537 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1538 struct task_struct
*p
, int *notask_error
,
1539 enum pid_type type
, struct pid
*pid
, int options
,
1540 struct siginfo __user
*infop
,
1541 int __user
*stat_addr
, struct rusage __user
*ru
)
1543 int ret
= eligible_child(type
, pid
, options
, p
);
1547 if (unlikely(ret
< 0)) {
1549 * If we have not yet seen any eligible child,
1550 * then let this error code replace -ECHILD.
1551 * A permission error will give the user a clue
1552 * to look for security policy problems, rather
1553 * than for mysterious wait bugs.
1556 *notask_error
= ret
;
1559 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1561 * This child is hidden by ptrace.
1562 * We aren't allowed to see it now, but eventually we will.
1568 if (p
->exit_state
== EXIT_DEAD
)
1572 * We don't reap group leaders with subthreads.
1574 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1575 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1578 * It's stopped or running now, so it might
1579 * later continue, exit, or stop again.
1583 if (task_is_stopped_or_traced(p
))
1584 return wait_task_stopped(ptrace
, p
, options
,
1585 infop
, stat_addr
, ru
);
1587 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1591 * Do the work of do_wait() for one thread in the group, @tsk.
1593 * -ECHILD should be in *@notask_error before the first call.
1594 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1595 * Returns zero if the search for a child should continue; then
1596 * *@notask_error is 0 if there were any eligible children,
1597 * or another error from security_task_wait(), or still -ECHILD.
1599 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1600 enum pid_type type
, struct pid
*pid
, int options
,
1601 struct siginfo __user
*infop
, int __user
*stat_addr
,
1602 struct rusage __user
*ru
)
1604 struct task_struct
*p
;
1606 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1608 * Do not consider detached threads.
1610 if (!task_detached(p
)) {
1611 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1613 infop
, stat_addr
, ru
);
1622 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1623 enum pid_type type
, struct pid
*pid
, int options
,
1624 struct siginfo __user
*infop
, int __user
*stat_addr
,
1625 struct rusage __user
*ru
)
1627 struct task_struct
*p
;
1630 * Traditionally we see ptrace'd stopped tasks regardless of options.
1632 options
|= WUNTRACED
;
1634 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1635 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1637 infop
, stat_addr
, ru
);
1645 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1646 struct siginfo __user
*infop
, int __user
*stat_addr
,
1647 struct rusage __user
*ru
)
1649 DECLARE_WAITQUEUE(wait
, current
);
1650 struct task_struct
*tsk
;
1653 trace_sched_process_wait(pid
);
1655 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1658 * If there is nothing that can match our critiera just get out.
1659 * We will clear @retval to zero if we see any child that might later
1660 * match our criteria, even if we are not able to reap it yet.
1663 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1666 current
->state
= TASK_INTERRUPTIBLE
;
1667 read_lock(&tasklist_lock
);
1670 int tsk_result
= do_wait_thread(tsk
, &retval
,
1672 infop
, stat_addr
, ru
);
1674 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1676 infop
, stat_addr
, ru
);
1679 * tasklist_lock is unlocked and we have a final result.
1681 retval
= tsk_result
;
1685 if (options
& __WNOTHREAD
)
1687 tsk
= next_thread(tsk
);
1688 BUG_ON(tsk
->signal
!= current
->signal
);
1689 } while (tsk
!= current
);
1690 read_unlock(&tasklist_lock
);
1692 if (!retval
&& !(options
& WNOHANG
)) {
1693 retval
= -ERESTARTSYS
;
1694 if (!signal_pending(current
)) {
1701 current
->state
= TASK_RUNNING
;
1702 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1708 * For a WNOHANG return, clear out all the fields
1709 * we would set so the user can easily tell the
1713 retval
= put_user(0, &infop
->si_signo
);
1715 retval
= put_user(0, &infop
->si_errno
);
1717 retval
= put_user(0, &infop
->si_code
);
1719 retval
= put_user(0, &infop
->si_pid
);
1721 retval
= put_user(0, &infop
->si_uid
);
1723 retval
= put_user(0, &infop
->si_status
);
1729 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1730 infop
, int, options
, struct rusage __user
*, ru
)
1732 struct pid
*pid
= NULL
;
1736 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1738 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1751 type
= PIDTYPE_PGID
;
1759 if (type
< PIDTYPE_MAX
)
1760 pid
= find_get_pid(upid
);
1761 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1764 /* avoid REGPARM breakage on x86: */
1765 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1769 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1770 int, options
, struct rusage __user
*, ru
)
1772 struct pid
*pid
= NULL
;
1776 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1777 __WNOTHREAD
|__WCLONE
|__WALL
))
1782 else if (upid
< 0) {
1783 type
= PIDTYPE_PGID
;
1784 pid
= find_get_pid(-upid
);
1785 } else if (upid
== 0) {
1786 type
= PIDTYPE_PGID
;
1787 pid
= get_pid(task_pgrp(current
));
1788 } else /* upid > 0 */ {
1790 pid
= find_get_pid(upid
);
1793 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1796 /* avoid REGPARM breakage on x86: */
1797 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1801 #ifdef __ARCH_WANT_SYS_WAITPID
1804 * sys_waitpid() remains for compatibility. waitpid() should be
1805 * implemented by calling sys_wait4() from libc.a.
1807 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1809 return sys_wait4(pid
, stat_addr
, options
, NULL
);