4 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/capability.h>
12 #include <linux/completion.h>
13 #include <linux/personality.h>
14 #include <linux/tty.h>
15 #include <linux/mnt_namespace.h>
16 #include <linux/iocontext.h>
17 #include <linux/key.h>
18 #include <linux/security.h>
19 #include <linux/cpu.h>
20 #include <linux/acct.h>
21 #include <linux/tsacct_kern.h>
22 #include <linux/file.h>
23 #include <linux/fdtable.h>
24 #include <linux/binfmts.h>
25 #include <linux/nsproxy.h>
26 #include <linux/pid_namespace.h>
27 #include <linux/ptrace.h>
28 #include <linux/profile.h>
29 #include <linux/mount.h>
30 #include <linux/proc_fs.h>
31 #include <linux/kthread.h>
32 #include <linux/mempolicy.h>
33 #include <linux/taskstats_kern.h>
34 #include <linux/delayacct.h>
35 #include <linux/freezer.h>
36 #include <linux/cgroup.h>
37 #include <linux/syscalls.h>
38 #include <linux/signal.h>
39 #include <linux/posix-timers.h>
40 #include <linux/cn_proc.h>
41 #include <linux/mutex.h>
42 #include <linux/futex.h>
43 #include <linux/pipe_fs_i.h>
44 #include <linux/audit.h> /* for audit_free() */
45 #include <linux/resource.h>
46 #include <linux/blkdev.h>
47 #include <linux/task_io_accounting_ops.h>
48 #include <linux/tracehook.h>
49 #include <trace/sched.h>
51 #include <asm/uaccess.h>
52 #include <asm/unistd.h>
53 #include <asm/pgtable.h>
54 #include <asm/mmu_context.h>
56 DEFINE_TRACE(sched_process_free
);
57 DEFINE_TRACE(sched_process_exit
);
58 DEFINE_TRACE(sched_process_wait
);
60 static void exit_mm(struct task_struct
* tsk
);
62 static inline int task_detached(struct task_struct
*p
)
64 return p
->exit_signal
== -1;
67 static void __unhash_process(struct task_struct
*p
)
70 detach_pid(p
, PIDTYPE_PID
);
71 if (thread_group_leader(p
)) {
72 detach_pid(p
, PIDTYPE_PGID
);
73 detach_pid(p
, PIDTYPE_SID
);
75 list_del_rcu(&p
->tasks
);
76 __get_cpu_var(process_counts
)--;
78 list_del_rcu(&p
->thread_group
);
79 list_del_init(&p
->sibling
);
83 * This function expects the tasklist_lock write-locked.
85 static void __exit_signal(struct task_struct
*tsk
)
87 struct signal_struct
*sig
= tsk
->signal
;
88 struct sighand_struct
*sighand
;
91 BUG_ON(!atomic_read(&sig
->count
));
93 sighand
= rcu_dereference(tsk
->sighand
);
94 spin_lock(&sighand
->siglock
);
96 posix_cpu_timers_exit(tsk
);
97 if (atomic_dec_and_test(&sig
->count
))
98 posix_cpu_timers_exit_group(tsk
);
101 * If there is any task waiting for the group exit
104 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
105 wake_up_process(sig
->group_exit_task
);
107 if (tsk
== sig
->curr_target
)
108 sig
->curr_target
= next_thread(tsk
);
110 * Accumulate here the counters for all threads but the
111 * group leader as they die, so they can be added into
112 * the process-wide totals when those are taken.
113 * The group leader stays around as a zombie as long
114 * as there are other threads. When it gets reaped,
115 * the exit.c code will add its counts into these totals.
116 * We won't ever get here for the group leader, since it
117 * will have been the last reference on the signal_struct.
119 sig
->gtime
= cputime_add(sig
->gtime
, task_gtime(tsk
));
120 sig
->min_flt
+= tsk
->min_flt
;
121 sig
->maj_flt
+= tsk
->maj_flt
;
122 sig
->nvcsw
+= tsk
->nvcsw
;
123 sig
->nivcsw
+= tsk
->nivcsw
;
124 sig
->inblock
+= task_io_get_inblock(tsk
);
125 sig
->oublock
+= task_io_get_oublock(tsk
);
126 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
127 sig
= NULL
; /* Marker for below. */
130 __unhash_process(tsk
);
133 * Do this under ->siglock, we can race with another thread
134 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
136 flush_sigqueue(&tsk
->pending
);
140 spin_unlock(&sighand
->siglock
);
142 __cleanup_sighand(sighand
);
143 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
145 flush_sigqueue(&sig
->shared_pending
);
146 taskstats_tgid_free(sig
);
148 * Make sure ->signal can't go away under rq->lock,
149 * see account_group_exec_runtime().
151 task_rq_unlock_wait(tsk
);
152 __cleanup_signal(sig
);
156 static void delayed_put_task_struct(struct rcu_head
*rhp
)
158 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
160 trace_sched_process_free(tsk
);
161 put_task_struct(tsk
);
165 void release_task(struct task_struct
* p
)
167 struct task_struct
*leader
;
170 tracehook_prepare_release_task(p
);
171 atomic_dec(&p
->user
->processes
);
173 write_lock_irq(&tasklist_lock
);
174 tracehook_finish_release_task(p
);
178 * If we are the last non-leader member of the thread
179 * group, and the leader is zombie, then notify the
180 * group leader's parent process. (if it wants notification.)
183 leader
= p
->group_leader
;
184 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
185 BUG_ON(task_detached(leader
));
186 do_notify_parent(leader
, leader
->exit_signal
);
188 * If we were the last child thread and the leader has
189 * exited already, and the leader's parent ignores SIGCHLD,
190 * then we are the one who should release the leader.
192 * do_notify_parent() will have marked it self-reaping in
195 zap_leader
= task_detached(leader
);
198 * This maintains the invariant that release_task()
199 * only runs on a task in EXIT_DEAD, just for sanity.
202 leader
->exit_state
= EXIT_DEAD
;
205 write_unlock_irq(&tasklist_lock
);
207 call_rcu(&p
->rcu
, delayed_put_task_struct
);
210 if (unlikely(zap_leader
))
215 * This checks not only the pgrp, but falls back on the pid if no
216 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
219 * The caller must hold rcu lock or the tasklist lock.
221 struct pid
*session_of_pgrp(struct pid
*pgrp
)
223 struct task_struct
*p
;
224 struct pid
*sid
= NULL
;
226 p
= pid_task(pgrp
, PIDTYPE_PGID
);
228 p
= pid_task(pgrp
, PIDTYPE_PID
);
230 sid
= task_session(p
);
236 * Determine if a process group is "orphaned", according to the POSIX
237 * definition in 2.2.2.52. Orphaned process groups are not to be affected
238 * by terminal-generated stop signals. Newly orphaned process groups are
239 * to receive a SIGHUP and a SIGCONT.
241 * "I ask you, have you ever known what it is to be an orphan?"
243 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
245 struct task_struct
*p
;
247 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
248 if ((p
== ignored_task
) ||
249 (p
->exit_state
&& thread_group_empty(p
)) ||
250 is_global_init(p
->real_parent
))
253 if (task_pgrp(p
->real_parent
) != pgrp
&&
254 task_session(p
->real_parent
) == task_session(p
))
256 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
261 int is_current_pgrp_orphaned(void)
265 read_lock(&tasklist_lock
);
266 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
267 read_unlock(&tasklist_lock
);
272 static int has_stopped_jobs(struct pid
*pgrp
)
275 struct task_struct
*p
;
277 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
278 if (!task_is_stopped(p
))
282 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
287 * Check to see if any process groups have become orphaned as
288 * a result of our exiting, and if they have any stopped jobs,
289 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
292 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
294 struct pid
*pgrp
= task_pgrp(tsk
);
295 struct task_struct
*ignored_task
= tsk
;
298 /* exit: our father is in a different pgrp than
299 * we are and we were the only connection outside.
301 parent
= tsk
->real_parent
;
303 /* reparent: our child is in a different pgrp than
304 * we are, and it was the only connection outside.
308 if (task_pgrp(parent
) != pgrp
&&
309 task_session(parent
) == task_session(tsk
) &&
310 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
311 has_stopped_jobs(pgrp
)) {
312 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
313 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
318 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
320 * If a kernel thread is launched as a result of a system call, or if
321 * it ever exits, it should generally reparent itself to kthreadd so it
322 * isn't in the way of other processes and is correctly cleaned up on exit.
324 * The various task state such as scheduling policy and priority may have
325 * been inherited from a user process, so we reset them to sane values here.
327 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
329 static void reparent_to_kthreadd(void)
331 write_lock_irq(&tasklist_lock
);
333 ptrace_unlink(current
);
334 /* Reparent to init */
335 current
->real_parent
= current
->parent
= kthreadd_task
;
336 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
338 /* Set the exit signal to SIGCHLD so we signal init on exit */
339 current
->exit_signal
= SIGCHLD
;
341 if (task_nice(current
) < 0)
342 set_user_nice(current
, 0);
346 security_task_reparent_to_init(current
);
347 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
348 sizeof(current
->signal
->rlim
));
349 atomic_inc(&(INIT_USER
->__count
));
350 write_unlock_irq(&tasklist_lock
);
351 switch_uid(INIT_USER
);
354 void __set_special_pids(struct pid
*pid
)
356 struct task_struct
*curr
= current
->group_leader
;
357 pid_t nr
= pid_nr(pid
);
359 if (task_session(curr
) != pid
) {
360 change_pid(curr
, PIDTYPE_SID
, pid
);
361 set_task_session(curr
, nr
);
363 if (task_pgrp(curr
) != pid
) {
364 change_pid(curr
, PIDTYPE_PGID
, pid
);
365 set_task_pgrp(curr
, nr
);
369 static void set_special_pids(struct pid
*pid
)
371 write_lock_irq(&tasklist_lock
);
372 __set_special_pids(pid
);
373 write_unlock_irq(&tasklist_lock
);
377 * Let kernel threads use this to say that they
378 * allow a certain signal (since daemonize() will
379 * have disabled all of them by default).
381 int allow_signal(int sig
)
383 if (!valid_signal(sig
) || sig
< 1)
386 spin_lock_irq(¤t
->sighand
->siglock
);
387 sigdelset(¤t
->blocked
, sig
);
389 /* Kernel threads handle their own signals.
390 Let the signal code know it'll be handled, so
391 that they don't get converted to SIGKILL or
392 just silently dropped */
393 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
396 spin_unlock_irq(¤t
->sighand
->siglock
);
400 EXPORT_SYMBOL(allow_signal
);
402 int disallow_signal(int sig
)
404 if (!valid_signal(sig
) || sig
< 1)
407 spin_lock_irq(¤t
->sighand
->siglock
);
408 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
410 spin_unlock_irq(¤t
->sighand
->siglock
);
414 EXPORT_SYMBOL(disallow_signal
);
417 * Put all the gunge required to become a kernel thread without
418 * attached user resources in one place where it belongs.
421 void daemonize(const char *name
, ...)
424 struct fs_struct
*fs
;
427 va_start(args
, name
);
428 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
432 * If we were started as result of loading a module, close all of the
433 * user space pages. We don't need them, and if we didn't close them
434 * they would be locked into memory.
438 * We don't want to have TIF_FREEZE set if the system-wide hibernation
439 * or suspend transition begins right now.
441 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
443 if (current
->nsproxy
!= &init_nsproxy
) {
444 get_nsproxy(&init_nsproxy
);
445 switch_task_namespaces(current
, &init_nsproxy
);
447 set_special_pids(&init_struct_pid
);
448 proc_clear_tty(current
);
450 /* Block and flush all signals */
451 sigfillset(&blocked
);
452 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
453 flush_signals(current
);
455 /* Become as one with the init task */
457 exit_fs(current
); /* current->fs->count--; */
460 atomic_inc(&fs
->count
);
463 current
->files
= init_task
.files
;
464 atomic_inc(¤t
->files
->count
);
466 reparent_to_kthreadd();
469 EXPORT_SYMBOL(daemonize
);
471 static void close_files(struct files_struct
* files
)
479 * It is safe to dereference the fd table without RCU or
480 * ->file_lock because this is the last reference to the
483 fdt
= files_fdtable(files
);
487 if (i
>= fdt
->max_fds
)
489 set
= fdt
->open_fds
->fds_bits
[j
++];
492 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
494 filp_close(file
, files
);
504 struct files_struct
*get_files_struct(struct task_struct
*task
)
506 struct files_struct
*files
;
511 atomic_inc(&files
->count
);
517 void put_files_struct(struct files_struct
*files
)
521 if (atomic_dec_and_test(&files
->count
)) {
524 * Free the fd and fdset arrays if we expanded them.
525 * If the fdtable was embedded, pass files for freeing
526 * at the end of the RCU grace period. Otherwise,
527 * you can free files immediately.
529 fdt
= files_fdtable(files
);
530 if (fdt
!= &files
->fdtab
)
531 kmem_cache_free(files_cachep
, files
);
536 void reset_files_struct(struct files_struct
*files
)
538 struct task_struct
*tsk
= current
;
539 struct files_struct
*old
;
545 put_files_struct(old
);
548 void exit_files(struct task_struct
*tsk
)
550 struct files_struct
* files
= tsk
->files
;
556 put_files_struct(files
);
560 void put_fs_struct(struct fs_struct
*fs
)
562 /* No need to hold fs->lock if we are killing it */
563 if (atomic_dec_and_test(&fs
->count
)) {
566 kmem_cache_free(fs_cachep
, fs
);
570 void exit_fs(struct task_struct
*tsk
)
572 struct fs_struct
* fs
= tsk
->fs
;
582 EXPORT_SYMBOL_GPL(exit_fs
);
584 #ifdef CONFIG_MM_OWNER
586 * Task p is exiting and it owned mm, lets find a new owner for it
589 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
592 * If there are other users of the mm and the owner (us) is exiting
593 * we need to find a new owner to take on the responsibility.
595 if (atomic_read(&mm
->mm_users
) <= 1)
602 void mm_update_next_owner(struct mm_struct
*mm
)
604 struct task_struct
*c
, *g
, *p
= current
;
607 if (!mm_need_new_owner(mm
, p
))
610 read_lock(&tasklist_lock
);
612 * Search in the children
614 list_for_each_entry(c
, &p
->children
, sibling
) {
616 goto assign_new_owner
;
620 * Search in the siblings
622 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
624 goto assign_new_owner
;
628 * Search through everything else. We should not get
631 do_each_thread(g
, c
) {
633 goto assign_new_owner
;
634 } while_each_thread(g
, c
);
636 read_unlock(&tasklist_lock
);
638 * We found no owner yet mm_users > 1: this implies that we are
639 * most likely racing with swapoff (try_to_unuse()) or /proc or
640 * ptrace or page migration (get_task_mm()). Mark owner as NULL,
641 * so that subsystems can understand the callback and take action.
643 down_write(&mm
->mmap_sem
);
644 cgroup_mm_owner_callbacks(mm
->owner
, NULL
);
646 up_write(&mm
->mmap_sem
);
652 read_unlock(&tasklist_lock
);
653 down_write(&mm
->mmap_sem
);
655 * The task_lock protects c->mm from changing.
656 * We always want mm->owner->mm == mm
661 up_write(&mm
->mmap_sem
);
665 cgroup_mm_owner_callbacks(mm
->owner
, c
);
668 up_write(&mm
->mmap_sem
);
671 #endif /* CONFIG_MM_OWNER */
674 * Turn us into a lazy TLB process if we
677 static void exit_mm(struct task_struct
* tsk
)
679 struct mm_struct
*mm
= tsk
->mm
;
680 struct core_state
*core_state
;
686 * Serialize with any possible pending coredump.
687 * We must hold mmap_sem around checking core_state
688 * and clearing tsk->mm. The core-inducing thread
689 * will increment ->nr_threads for each thread in the
690 * group with ->mm != NULL.
692 down_read(&mm
->mmap_sem
);
693 core_state
= mm
->core_state
;
695 struct core_thread self
;
696 up_read(&mm
->mmap_sem
);
699 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
701 * Implies mb(), the result of xchg() must be visible
702 * to core_state->dumper.
704 if (atomic_dec_and_test(&core_state
->nr_threads
))
705 complete(&core_state
->startup
);
708 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
709 if (!self
.task
) /* see coredump_finish() */
713 __set_task_state(tsk
, TASK_RUNNING
);
714 down_read(&mm
->mmap_sem
);
716 atomic_inc(&mm
->mm_count
);
717 BUG_ON(mm
!= tsk
->active_mm
);
718 /* more a memory barrier than a real lock */
721 up_read(&mm
->mmap_sem
);
722 enter_lazy_tlb(mm
, current
);
723 /* We don't want this task to be frozen prematurely */
724 clear_freeze_flag(tsk
);
726 mm_update_next_owner(mm
);
731 * Return nonzero if @parent's children should reap themselves.
733 * Called with write_lock_irq(&tasklist_lock) held.
735 static int ignoring_children(struct task_struct
*parent
)
738 struct sighand_struct
*psig
= parent
->sighand
;
740 spin_lock_irqsave(&psig
->siglock
, flags
);
741 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
742 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
743 spin_unlock_irqrestore(&psig
->siglock
, flags
);
748 * Detach all tasks we were using ptrace on.
749 * Any that need to be release_task'd are put on the @dead list.
751 * Called with write_lock(&tasklist_lock) held.
753 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
755 struct task_struct
*p
, *n
;
758 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
761 if (p
->exit_state
!= EXIT_ZOMBIE
)
765 * If it's a zombie, our attachedness prevented normal
766 * parent notification or self-reaping. Do notification
767 * now if it would have happened earlier. If it should
768 * reap itself, add it to the @dead list. We can't call
769 * release_task() here because we already hold tasklist_lock.
771 * If it's our own child, there is no notification to do.
772 * But if our normal children self-reap, then this child
773 * was prevented by ptrace and we must reap it now.
775 if (!task_detached(p
) && thread_group_empty(p
)) {
776 if (!same_thread_group(p
->real_parent
, parent
))
777 do_notify_parent(p
, p
->exit_signal
);
780 ign
= ignoring_children(parent
);
786 if (task_detached(p
)) {
788 * Mark it as in the process of being reaped.
790 p
->exit_state
= EXIT_DEAD
;
791 list_add(&p
->ptrace_entry
, dead
);
797 * Finish up exit-time ptrace cleanup.
799 * Called without locks.
801 static void ptrace_exit_finish(struct task_struct
*parent
,
802 struct list_head
*dead
)
804 struct task_struct
*p
, *n
;
806 BUG_ON(!list_empty(&parent
->ptraced
));
808 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
809 list_del_init(&p
->ptrace_entry
);
814 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
816 if (p
->pdeath_signal
)
817 /* We already hold the tasklist_lock here. */
818 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
820 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
822 /* If this is a threaded reparent there is no need to
823 * notify anyone anything has happened.
825 if (same_thread_group(p
->real_parent
, father
))
828 /* We don't want people slaying init. */
829 if (!task_detached(p
))
830 p
->exit_signal
= SIGCHLD
;
832 /* If we'd notified the old parent about this child's death,
833 * also notify the new parent.
835 if (!ptrace_reparented(p
) &&
836 p
->exit_state
== EXIT_ZOMBIE
&&
837 !task_detached(p
) && thread_group_empty(p
))
838 do_notify_parent(p
, p
->exit_signal
);
840 kill_orphaned_pgrp(p
, father
);
844 * When we die, we re-parent all our children.
845 * Try to give them to another thread in our thread
846 * group, and if no such member exists, give it to
847 * the child reaper process (ie "init") in our pid
850 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
852 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
853 struct task_struct
*thread
;
856 while_each_thread(father
, thread
) {
857 if (thread
->flags
& PF_EXITING
)
859 if (unlikely(pid_ns
->child_reaper
== father
))
860 pid_ns
->child_reaper
= thread
;
864 if (unlikely(pid_ns
->child_reaper
== father
)) {
865 write_unlock_irq(&tasklist_lock
);
866 if (unlikely(pid_ns
== &init_pid_ns
))
867 panic("Attempted to kill init!");
869 zap_pid_ns_processes(pid_ns
);
870 write_lock_irq(&tasklist_lock
);
872 * We can not clear ->child_reaper or leave it alone.
873 * There may by stealth EXIT_DEAD tasks on ->children,
874 * forget_original_parent() must move them somewhere.
876 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
879 return pid_ns
->child_reaper
;
882 static void forget_original_parent(struct task_struct
*father
)
884 struct task_struct
*p
, *n
, *reaper
;
885 LIST_HEAD(ptrace_dead
);
887 write_lock_irq(&tasklist_lock
);
888 reaper
= find_new_reaper(father
);
890 * First clean up ptrace if we were using it.
892 ptrace_exit(father
, &ptrace_dead
);
894 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
895 p
->real_parent
= reaper
;
896 if (p
->parent
== father
) {
898 p
->parent
= p
->real_parent
;
900 reparent_thread(p
, father
);
903 write_unlock_irq(&tasklist_lock
);
904 BUG_ON(!list_empty(&father
->children
));
906 ptrace_exit_finish(father
, &ptrace_dead
);
910 * Send signals to all our closest relatives so that they know
911 * to properly mourn us..
913 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
919 * This does two things:
921 * A. Make init inherit all the child processes
922 * B. Check to see if any process groups have become orphaned
923 * as a result of our exiting, and if they have any stopped
924 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
926 forget_original_parent(tsk
);
927 exit_task_namespaces(tsk
);
929 write_lock_irq(&tasklist_lock
);
931 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
933 /* Let father know we died
935 * Thread signals are configurable, but you aren't going to use
936 * that to send signals to arbitary processes.
937 * That stops right now.
939 * If the parent exec id doesn't match the exec id we saved
940 * when we started then we know the parent has changed security
943 * If our self_exec id doesn't match our parent_exec_id then
944 * we have changed execution domain as these two values started
945 * the same after a fork.
947 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
948 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
949 tsk
->self_exec_id
!= tsk
->parent_exec_id
) &&
951 tsk
->exit_signal
= SIGCHLD
;
953 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
955 signal
= do_notify_parent(tsk
, signal
);
957 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
959 /* mt-exec, de_thread() is waiting for us */
960 if (thread_group_leader(tsk
) &&
961 tsk
->signal
->group_exit_task
&&
962 tsk
->signal
->notify_count
< 0)
963 wake_up_process(tsk
->signal
->group_exit_task
);
965 write_unlock_irq(&tasklist_lock
);
967 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
969 /* If the process is dead, release it - nobody will wait for it */
970 if (signal
== DEATH_REAP
)
974 #ifdef CONFIG_DEBUG_STACK_USAGE
975 static void check_stack_usage(void)
977 static DEFINE_SPINLOCK(low_water_lock
);
978 static int lowest_to_date
= THREAD_SIZE
;
979 unsigned long *n
= end_of_stack(current
);
984 free
= (unsigned long)n
- (unsigned long)end_of_stack(current
);
986 if (free
>= lowest_to_date
)
989 spin_lock(&low_water_lock
);
990 if (free
< lowest_to_date
) {
991 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
993 current
->comm
, free
);
994 lowest_to_date
= free
;
996 spin_unlock(&low_water_lock
);
999 static inline void check_stack_usage(void) {}
1002 NORET_TYPE
void do_exit(long code
)
1004 struct task_struct
*tsk
= current
;
1007 profile_task_exit(tsk
);
1009 WARN_ON(atomic_read(&tsk
->fs_excl
));
1011 if (unlikely(in_interrupt()))
1012 panic("Aiee, killing interrupt handler!");
1013 if (unlikely(!tsk
->pid
))
1014 panic("Attempted to kill the idle task!");
1016 tracehook_report_exit(&code
);
1019 * We're taking recursive faults here in do_exit. Safest is to just
1020 * leave this task alone and wait for reboot.
1022 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1024 "Fixing recursive fault but reboot is needed!\n");
1026 * We can do this unlocked here. The futex code uses
1027 * this flag just to verify whether the pi state
1028 * cleanup has been done or not. In the worst case it
1029 * loops once more. We pretend that the cleanup was
1030 * done as there is no way to return. Either the
1031 * OWNER_DIED bit is set by now or we push the blocked
1032 * task into the wait for ever nirwana as well.
1034 tsk
->flags
|= PF_EXITPIDONE
;
1035 if (tsk
->io_context
)
1037 set_current_state(TASK_UNINTERRUPTIBLE
);
1041 exit_signals(tsk
); /* sets PF_EXITING */
1043 * tsk->flags are checked in the futex code to protect against
1044 * an exiting task cleaning up the robust pi futexes.
1047 spin_unlock_wait(&tsk
->pi_lock
);
1049 if (unlikely(in_atomic()))
1050 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1051 current
->comm
, task_pid_nr(current
),
1054 acct_update_integrals(tsk
);
1056 update_hiwater_rss(tsk
->mm
);
1057 update_hiwater_vm(tsk
->mm
);
1059 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1061 hrtimer_cancel(&tsk
->signal
->real_timer
);
1062 exit_itimers(tsk
->signal
);
1064 acct_collect(code
, group_dead
);
1067 if (unlikely(tsk
->audit_context
))
1070 tsk
->exit_code
= code
;
1071 taskstats_exit(tsk
, group_dead
);
1077 trace_sched_process_exit(tsk
);
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
;
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
;
1306 struct task_cputime cputime
;
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 * We use thread_group_cputime() to get times for the thread
1324 * group, which consolidates times for all threads in the
1325 * group including the group leader.
1327 thread_group_cputime(p
, &cputime
);
1328 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1329 psig
= p
->parent
->signal
;
1332 cputime_add(psig
->cutime
,
1333 cputime_add(cputime
.utime
,
1336 cputime_add(psig
->cstime
,
1337 cputime_add(cputime
.stime
,
1340 cputime_add(psig
->cgtime
,
1341 cputime_add(p
->gtime
,
1342 cputime_add(sig
->gtime
,
1345 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1347 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1349 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1351 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1353 task_io_get_inblock(p
) +
1354 sig
->inblock
+ sig
->cinblock
;
1356 task_io_get_oublock(p
) +
1357 sig
->oublock
+ sig
->coublock
;
1358 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1359 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1360 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1364 * Now we are sure this task is interesting, and no other
1365 * thread can reap it because we set its state to EXIT_DEAD.
1367 read_unlock(&tasklist_lock
);
1369 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1370 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1371 ? p
->signal
->group_exit_code
: p
->exit_code
;
1372 if (!retval
&& stat_addr
)
1373 retval
= put_user(status
, stat_addr
);
1374 if (!retval
&& infop
)
1375 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1376 if (!retval
&& infop
)
1377 retval
= put_user(0, &infop
->si_errno
);
1378 if (!retval
&& infop
) {
1381 if ((status
& 0x7f) == 0) {
1385 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1388 retval
= put_user((short)why
, &infop
->si_code
);
1390 retval
= put_user(status
, &infop
->si_status
);
1392 if (!retval
&& infop
)
1393 retval
= put_user(pid
, &infop
->si_pid
);
1394 if (!retval
&& infop
)
1395 retval
= put_user(p
->uid
, &infop
->si_uid
);
1400 write_lock_irq(&tasklist_lock
);
1401 /* We dropped tasklist, ptracer could die and untrace */
1404 * If this is not a detached task, notify the parent.
1405 * If it's still not detached after that, don't release
1408 if (!task_detached(p
)) {
1409 do_notify_parent(p
, p
->exit_signal
);
1410 if (!task_detached(p
)) {
1411 p
->exit_state
= EXIT_ZOMBIE
;
1415 write_unlock_irq(&tasklist_lock
);
1424 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1425 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1426 * the lock and this task is uninteresting. If we return nonzero, we have
1427 * released the lock and the system call should return.
1429 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1430 int options
, struct siginfo __user
*infop
,
1431 int __user
*stat_addr
, struct rusage __user
*ru
)
1433 int retval
, exit_code
, why
;
1434 uid_t uid
= 0; /* unneeded, required by compiler */
1437 if (!(options
& WUNTRACED
))
1441 spin_lock_irq(&p
->sighand
->siglock
);
1443 if (unlikely(!task_is_stopped_or_traced(p
)))
1446 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1448 * A group stop is in progress and this is the group leader.
1449 * We won't report until all threads have stopped.
1453 exit_code
= p
->exit_code
;
1457 if (!unlikely(options
& WNOWAIT
))
1462 spin_unlock_irq(&p
->sighand
->siglock
);
1467 * Now we are pretty sure this task is interesting.
1468 * Make sure it doesn't get reaped out from under us while we
1469 * give up the lock and then examine it below. We don't want to
1470 * keep holding onto the tasklist_lock while we call getrusage and
1471 * possibly take page faults for user memory.
1474 pid
= task_pid_vnr(p
);
1475 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1476 read_unlock(&tasklist_lock
);
1478 if (unlikely(options
& WNOWAIT
))
1479 return wait_noreap_copyout(p
, pid
, uid
,
1483 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1484 if (!retval
&& stat_addr
)
1485 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1486 if (!retval
&& infop
)
1487 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1488 if (!retval
&& infop
)
1489 retval
= put_user(0, &infop
->si_errno
);
1490 if (!retval
&& infop
)
1491 retval
= put_user((short)why
, &infop
->si_code
);
1492 if (!retval
&& infop
)
1493 retval
= put_user(exit_code
, &infop
->si_status
);
1494 if (!retval
&& infop
)
1495 retval
= put_user(pid
, &infop
->si_pid
);
1496 if (!retval
&& infop
)
1497 retval
= put_user(uid
, &infop
->si_uid
);
1507 * Handle do_wait work for one task in a live, non-stopped state.
1508 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1509 * the lock and this task is uninteresting. If we return nonzero, we have
1510 * released the lock and the system call should return.
1512 static int wait_task_continued(struct task_struct
*p
, int options
,
1513 struct siginfo __user
*infop
,
1514 int __user
*stat_addr
, struct rusage __user
*ru
)
1520 if (!unlikely(options
& WCONTINUED
))
1523 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1526 spin_lock_irq(&p
->sighand
->siglock
);
1527 /* Re-check with the lock held. */
1528 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1529 spin_unlock_irq(&p
->sighand
->siglock
);
1532 if (!unlikely(options
& WNOWAIT
))
1533 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1534 spin_unlock_irq(&p
->sighand
->siglock
);
1536 pid
= task_pid_vnr(p
);
1539 read_unlock(&tasklist_lock
);
1542 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1544 if (!retval
&& stat_addr
)
1545 retval
= put_user(0xffff, stat_addr
);
1549 retval
= wait_noreap_copyout(p
, pid
, uid
,
1550 CLD_CONTINUED
, SIGCONT
,
1552 BUG_ON(retval
== 0);
1559 * Consider @p for a wait by @parent.
1561 * -ECHILD should be in *@notask_error before the first call.
1562 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1563 * Returns zero if the search for a child should continue;
1564 * then *@notask_error is 0 if @p is an eligible child,
1565 * or another error from security_task_wait(), or still -ECHILD.
1567 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1568 struct task_struct
*p
, int *notask_error
,
1569 enum pid_type type
, struct pid
*pid
, int options
,
1570 struct siginfo __user
*infop
,
1571 int __user
*stat_addr
, struct rusage __user
*ru
)
1573 int ret
= eligible_child(type
, pid
, options
, p
);
1577 if (unlikely(ret
< 0)) {
1579 * If we have not yet seen any eligible child,
1580 * then let this error code replace -ECHILD.
1581 * A permission error will give the user a clue
1582 * to look for security policy problems, rather
1583 * than for mysterious wait bugs.
1586 *notask_error
= ret
;
1589 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1591 * This child is hidden by ptrace.
1592 * We aren't allowed to see it now, but eventually we will.
1598 if (p
->exit_state
== EXIT_DEAD
)
1602 * We don't reap group leaders with subthreads.
1604 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1605 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1608 * It's stopped or running now, so it might
1609 * later continue, exit, or stop again.
1613 if (task_is_stopped_or_traced(p
))
1614 return wait_task_stopped(ptrace
, p
, options
,
1615 infop
, stat_addr
, ru
);
1617 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1621 * Do the work of do_wait() for one thread in the group, @tsk.
1623 * -ECHILD should be in *@notask_error before the first call.
1624 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1625 * Returns zero if the search for a child should continue; then
1626 * *@notask_error is 0 if there were any eligible children,
1627 * or another error from security_task_wait(), or still -ECHILD.
1629 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1630 enum pid_type type
, struct pid
*pid
, int options
,
1631 struct siginfo __user
*infop
, int __user
*stat_addr
,
1632 struct rusage __user
*ru
)
1634 struct task_struct
*p
;
1636 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1638 * Do not consider detached threads.
1640 if (!task_detached(p
)) {
1641 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1643 infop
, stat_addr
, ru
);
1652 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1653 enum pid_type type
, struct pid
*pid
, int options
,
1654 struct siginfo __user
*infop
, int __user
*stat_addr
,
1655 struct rusage __user
*ru
)
1657 struct task_struct
*p
;
1660 * Traditionally we see ptrace'd stopped tasks regardless of options.
1662 options
|= WUNTRACED
;
1664 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1665 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1667 infop
, stat_addr
, ru
);
1675 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1676 struct siginfo __user
*infop
, int __user
*stat_addr
,
1677 struct rusage __user
*ru
)
1679 DECLARE_WAITQUEUE(wait
, current
);
1680 struct task_struct
*tsk
;
1683 trace_sched_process_wait(pid
);
1685 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1688 * If there is nothing that can match our critiera just get out.
1689 * We will clear @retval to zero if we see any child that might later
1690 * match our criteria, even if we are not able to reap it yet.
1693 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1696 current
->state
= TASK_INTERRUPTIBLE
;
1697 read_lock(&tasklist_lock
);
1700 int tsk_result
= do_wait_thread(tsk
, &retval
,
1702 infop
, stat_addr
, ru
);
1704 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1706 infop
, stat_addr
, ru
);
1709 * tasklist_lock is unlocked and we have a final result.
1711 retval
= tsk_result
;
1715 if (options
& __WNOTHREAD
)
1717 tsk
= next_thread(tsk
);
1718 BUG_ON(tsk
->signal
!= current
->signal
);
1719 } while (tsk
!= current
);
1720 read_unlock(&tasklist_lock
);
1722 if (!retval
&& !(options
& WNOHANG
)) {
1723 retval
= -ERESTARTSYS
;
1724 if (!signal_pending(current
)) {
1731 current
->state
= TASK_RUNNING
;
1732 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1738 * For a WNOHANG return, clear out all the fields
1739 * we would set so the user can easily tell the
1743 retval
= put_user(0, &infop
->si_signo
);
1745 retval
= put_user(0, &infop
->si_errno
);
1747 retval
= put_user(0, &infop
->si_code
);
1749 retval
= put_user(0, &infop
->si_pid
);
1751 retval
= put_user(0, &infop
->si_uid
);
1753 retval
= put_user(0, &infop
->si_status
);
1759 asmlinkage
long sys_waitid(int which
, pid_t upid
,
1760 struct siginfo __user
*infop
, int options
,
1761 struct rusage __user
*ru
)
1763 struct pid
*pid
= NULL
;
1767 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1769 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1782 type
= PIDTYPE_PGID
;
1790 if (type
< PIDTYPE_MAX
)
1791 pid
= find_get_pid(upid
);
1792 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1795 /* avoid REGPARM breakage on x86: */
1796 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1800 asmlinkage
long sys_wait4(pid_t upid
, int __user
*stat_addr
,
1801 int options
, struct rusage __user
*ru
)
1803 struct pid
*pid
= NULL
;
1807 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1808 __WNOTHREAD
|__WCLONE
|__WALL
))
1813 else if (upid
< 0) {
1814 type
= PIDTYPE_PGID
;
1815 pid
= find_get_pid(-upid
);
1816 } else if (upid
== 0) {
1817 type
= PIDTYPE_PGID
;
1818 pid
= get_pid(task_pgrp(current
));
1819 } else /* upid > 0 */ {
1821 pid
= find_get_pid(upid
);
1824 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1827 /* avoid REGPARM breakage on x86: */
1828 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1832 #ifdef __ARCH_WANT_SYS_WAITPID
1835 * sys_waitpid() remains for compatibility. waitpid() should be
1836 * implemented by calling sys_wait4() from libc.a.
1838 asmlinkage
long sys_waitpid(pid_t pid
, int __user
*stat_addr
, int options
)
1840 return sys_wait4(pid
, stat_addr
, options
, NULL
);