4 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/capability.h>
12 #include <linux/completion.h>
13 #include <linux/personality.h>
14 #include <linux/tty.h>
15 #include <linux/mnt_namespace.h>
16 #include <linux/iocontext.h>
17 #include <linux/key.h>
18 #include <linux/security.h>
19 #include <linux/cpu.h>
20 #include <linux/acct.h>
21 #include <linux/tsacct_kern.h>
22 #include <linux/file.h>
23 #include <linux/fdtable.h>
24 #include <linux/binfmts.h>
25 #include <linux/nsproxy.h>
26 #include <linux/pid_namespace.h>
27 #include <linux/ptrace.h>
28 #include <linux/profile.h>
29 #include <linux/mount.h>
30 #include <linux/proc_fs.h>
31 #include <linux/kthread.h>
32 #include <linux/mempolicy.h>
33 #include <linux/taskstats_kern.h>
34 #include <linux/delayacct.h>
35 #include <linux/freezer.h>
36 #include <linux/cgroup.h>
37 #include <linux/syscalls.h>
38 #include <linux/signal.h>
39 #include <linux/posix-timers.h>
40 #include <linux/cn_proc.h>
41 #include <linux/mutex.h>
42 #include <linux/futex.h>
43 #include <linux/pipe_fs_i.h>
44 #include <linux/audit.h> /* for audit_free() */
45 #include <linux/resource.h>
46 #include <linux/blkdev.h>
47 #include <linux/task_io_accounting_ops.h>
48 #include <linux/tracehook.h>
49 #include <trace/sched.h>
51 #include <asm/uaccess.h>
52 #include <asm/unistd.h>
53 #include <asm/pgtable.h>
54 #include <asm/mmu_context.h>
56 static void exit_mm(struct task_struct
* tsk
);
58 static inline int task_detached(struct task_struct
*p
)
60 return p
->exit_signal
== -1;
63 static void __unhash_process(struct task_struct
*p
)
66 detach_pid(p
, PIDTYPE_PID
);
67 if (thread_group_leader(p
)) {
68 detach_pid(p
, PIDTYPE_PGID
);
69 detach_pid(p
, PIDTYPE_SID
);
71 list_del_rcu(&p
->tasks
);
72 __get_cpu_var(process_counts
)--;
74 list_del_rcu(&p
->thread_group
);
75 list_del_init(&p
->sibling
);
79 * This function expects the tasklist_lock write-locked.
81 static void __exit_signal(struct task_struct
*tsk
)
83 struct signal_struct
*sig
= tsk
->signal
;
84 struct sighand_struct
*sighand
;
87 BUG_ON(!atomic_read(&sig
->count
));
89 sighand
= rcu_dereference(tsk
->sighand
);
90 spin_lock(&sighand
->siglock
);
92 posix_cpu_timers_exit(tsk
);
93 if (atomic_dec_and_test(&sig
->count
))
94 posix_cpu_timers_exit_group(tsk
);
97 * If there is any task waiting for the group exit
100 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
101 wake_up_process(sig
->group_exit_task
);
103 if (tsk
== sig
->curr_target
)
104 sig
->curr_target
= next_thread(tsk
);
106 * Accumulate here the counters for all threads but the
107 * group leader as they die, so they can be added into
108 * the process-wide totals when those are taken.
109 * The group leader stays around as a zombie as long
110 * as there are other threads. When it gets reaped,
111 * the exit.c code will add its counts into these totals.
112 * We won't ever get here for the group leader, since it
113 * will have been the last reference on the signal_struct.
115 sig
->gtime
= cputime_add(sig
->gtime
, task_gtime(tsk
));
116 sig
->min_flt
+= tsk
->min_flt
;
117 sig
->maj_flt
+= tsk
->maj_flt
;
118 sig
->nvcsw
+= tsk
->nvcsw
;
119 sig
->nivcsw
+= tsk
->nivcsw
;
120 sig
->inblock
+= task_io_get_inblock(tsk
);
121 sig
->oublock
+= task_io_get_oublock(tsk
);
122 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
123 sig
= NULL
; /* Marker for below. */
126 __unhash_process(tsk
);
129 * Do this under ->siglock, we can race with another thread
130 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
132 flush_sigqueue(&tsk
->pending
);
136 spin_unlock(&sighand
->siglock
);
138 __cleanup_sighand(sighand
);
139 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
141 flush_sigqueue(&sig
->shared_pending
);
142 taskstats_tgid_free(sig
);
144 * Make sure ->signal can't go away under rq->lock,
145 * see account_group_exec_runtime().
147 task_rq_unlock_wait(tsk
);
148 __cleanup_signal(sig
);
152 static void delayed_put_task_struct(struct rcu_head
*rhp
)
154 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
156 #ifdef CONFIG_PERF_COUNTERS
157 WARN_ON_ONCE(!list_empty(&tsk
->perf_counter_ctx
.counter_list
));
159 trace_sched_process_free(tsk
);
160 put_task_struct(tsk
);
164 void release_task(struct task_struct
* p
)
166 struct task_struct
*leader
;
169 tracehook_prepare_release_task(p
);
170 atomic_dec(&p
->user
->processes
);
172 write_lock_irq(&tasklist_lock
);
173 tracehook_finish_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 * This maintains the invariant that release_task()
198 * only runs on a task in EXIT_DEAD, just for sanity.
201 leader
->exit_state
= EXIT_DEAD
;
204 write_unlock_irq(&tasklist_lock
);
206 call_rcu(&p
->rcu
, delayed_put_task_struct
);
209 if (unlikely(zap_leader
))
214 * This checks not only the pgrp, but falls back on the pid if no
215 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
218 * The caller must hold rcu lock or the tasklist lock.
220 struct pid
*session_of_pgrp(struct pid
*pgrp
)
222 struct task_struct
*p
;
223 struct pid
*sid
= NULL
;
225 p
= pid_task(pgrp
, PIDTYPE_PGID
);
227 p
= pid_task(pgrp
, PIDTYPE_PID
);
229 sid
= task_session(p
);
235 * Determine if a process group is "orphaned", according to the POSIX
236 * definition in 2.2.2.52. Orphaned process groups are not to be affected
237 * by terminal-generated stop signals. Newly orphaned process groups are
238 * to receive a SIGHUP and a SIGCONT.
240 * "I ask you, have you ever known what it is to be an orphan?"
242 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
244 struct task_struct
*p
;
246 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
247 if ((p
== ignored_task
) ||
248 (p
->exit_state
&& thread_group_empty(p
)) ||
249 is_global_init(p
->real_parent
))
252 if (task_pgrp(p
->real_parent
) != pgrp
&&
253 task_session(p
->real_parent
) == task_session(p
))
255 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
260 int is_current_pgrp_orphaned(void)
264 read_lock(&tasklist_lock
);
265 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
266 read_unlock(&tasklist_lock
);
271 static int has_stopped_jobs(struct pid
*pgrp
)
274 struct task_struct
*p
;
276 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
277 if (!task_is_stopped(p
))
281 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
286 * Check to see if any process groups have become orphaned as
287 * a result of our exiting, and if they have any stopped jobs,
288 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
291 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
293 struct pid
*pgrp
= task_pgrp(tsk
);
294 struct task_struct
*ignored_task
= tsk
;
297 /* exit: our father is in a different pgrp than
298 * we are and we were the only connection outside.
300 parent
= tsk
->real_parent
;
302 /* reparent: our child is in a different pgrp than
303 * we are, and it was the only connection outside.
307 if (task_pgrp(parent
) != pgrp
&&
308 task_session(parent
) == task_session(tsk
) &&
309 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
310 has_stopped_jobs(pgrp
)) {
311 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
312 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
317 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
319 * If a kernel thread is launched as a result of a system call, or if
320 * it ever exits, it should generally reparent itself to kthreadd so it
321 * isn't in the way of other processes and is correctly cleaned up on exit.
323 * The various task state such as scheduling policy and priority may have
324 * been inherited from a user process, so we reset them to sane values here.
326 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
328 static void reparent_to_kthreadd(void)
330 write_lock_irq(&tasklist_lock
);
332 ptrace_unlink(current
);
333 /* Reparent to init */
334 current
->real_parent
= current
->parent
= kthreadd_task
;
335 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
337 /* Set the exit signal to SIGCHLD so we signal init on exit */
338 current
->exit_signal
= SIGCHLD
;
340 if (task_nice(current
) < 0)
341 set_user_nice(current
, 0);
345 security_task_reparent_to_init(current
);
346 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
347 sizeof(current
->signal
->rlim
));
348 atomic_inc(&(INIT_USER
->__count
));
349 write_unlock_irq(&tasklist_lock
);
350 switch_uid(INIT_USER
);
353 void __set_special_pids(struct pid
*pid
)
355 struct task_struct
*curr
= current
->group_leader
;
356 pid_t nr
= pid_nr(pid
);
358 if (task_session(curr
) != pid
) {
359 change_pid(curr
, PIDTYPE_SID
, pid
);
360 set_task_session(curr
, nr
);
362 if (task_pgrp(curr
) != pid
) {
363 change_pid(curr
, PIDTYPE_PGID
, pid
);
364 set_task_pgrp(curr
, nr
);
368 static void set_special_pids(struct pid
*pid
)
370 write_lock_irq(&tasklist_lock
);
371 __set_special_pids(pid
);
372 write_unlock_irq(&tasklist_lock
);
376 * Let kernel threads use this to say that they
377 * allow a certain signal (since daemonize() will
378 * have disabled all of them by default).
380 int allow_signal(int sig
)
382 if (!valid_signal(sig
) || sig
< 1)
385 spin_lock_irq(¤t
->sighand
->siglock
);
386 sigdelset(¤t
->blocked
, sig
);
388 /* Kernel threads handle their own signals.
389 Let the signal code know it'll be handled, so
390 that they don't get converted to SIGKILL or
391 just silently dropped */
392 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
395 spin_unlock_irq(¤t
->sighand
->siglock
);
399 EXPORT_SYMBOL(allow_signal
);
401 int disallow_signal(int sig
)
403 if (!valid_signal(sig
) || sig
< 1)
406 spin_lock_irq(¤t
->sighand
->siglock
);
407 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
409 spin_unlock_irq(¤t
->sighand
->siglock
);
413 EXPORT_SYMBOL(disallow_signal
);
416 * Put all the gunge required to become a kernel thread without
417 * attached user resources in one place where it belongs.
420 void daemonize(const char *name
, ...)
423 struct fs_struct
*fs
;
426 va_start(args
, name
);
427 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
431 * If we were started as result of loading a module, close all of the
432 * user space pages. We don't need them, and if we didn't close them
433 * they would be locked into memory.
437 * We don't want to have TIF_FREEZE set if the system-wide hibernation
438 * or suspend transition begins right now.
440 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
442 if (current
->nsproxy
!= &init_nsproxy
) {
443 get_nsproxy(&init_nsproxy
);
444 switch_task_namespaces(current
, &init_nsproxy
);
446 set_special_pids(&init_struct_pid
);
447 proc_clear_tty(current
);
449 /* Block and flush all signals */
450 sigfillset(&blocked
);
451 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
452 flush_signals(current
);
454 /* Become as one with the init task */
456 exit_fs(current
); /* current->fs->count--; */
459 atomic_inc(&fs
->count
);
462 current
->files
= init_task
.files
;
463 atomic_inc(¤t
->files
->count
);
465 reparent_to_kthreadd();
468 EXPORT_SYMBOL(daemonize
);
470 static void close_files(struct files_struct
* files
)
478 * It is safe to dereference the fd table without RCU or
479 * ->file_lock because this is the last reference to the
482 fdt
= files_fdtable(files
);
486 if (i
>= fdt
->max_fds
)
488 set
= fdt
->open_fds
->fds_bits
[j
++];
491 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
493 filp_close(file
, files
);
503 struct files_struct
*get_files_struct(struct task_struct
*task
)
505 struct files_struct
*files
;
510 atomic_inc(&files
->count
);
516 void put_files_struct(struct files_struct
*files
)
520 if (atomic_dec_and_test(&files
->count
)) {
523 * Free the fd and fdset arrays if we expanded them.
524 * If the fdtable was embedded, pass files for freeing
525 * at the end of the RCU grace period. Otherwise,
526 * you can free files immediately.
528 fdt
= files_fdtable(files
);
529 if (fdt
!= &files
->fdtab
)
530 kmem_cache_free(files_cachep
, files
);
535 void reset_files_struct(struct files_struct
*files
)
537 struct task_struct
*tsk
= current
;
538 struct files_struct
*old
;
544 put_files_struct(old
);
547 void exit_files(struct task_struct
*tsk
)
549 struct files_struct
* files
= tsk
->files
;
555 put_files_struct(files
);
559 void put_fs_struct(struct fs_struct
*fs
)
561 /* No need to hold fs->lock if we are killing it */
562 if (atomic_dec_and_test(&fs
->count
)) {
565 kmem_cache_free(fs_cachep
, fs
);
569 void exit_fs(struct task_struct
*tsk
)
571 struct fs_struct
* fs
= tsk
->fs
;
581 EXPORT_SYMBOL_GPL(exit_fs
);
583 #ifdef CONFIG_MM_OWNER
585 * Task p is exiting and it owned mm, lets find a new owner for it
588 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
591 * If there are other users of the mm and the owner (us) is exiting
592 * we need to find a new owner to take on the responsibility.
594 if (atomic_read(&mm
->mm_users
) <= 1)
601 void mm_update_next_owner(struct mm_struct
*mm
)
603 struct task_struct
*c
, *g
, *p
= current
;
606 if (!mm_need_new_owner(mm
, p
))
609 read_lock(&tasklist_lock
);
611 * Search in the children
613 list_for_each_entry(c
, &p
->children
, sibling
) {
615 goto assign_new_owner
;
619 * Search in the siblings
621 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
623 goto assign_new_owner
;
627 * Search through everything else. We should not get
630 do_each_thread(g
, c
) {
632 goto assign_new_owner
;
633 } while_each_thread(g
, c
);
635 read_unlock(&tasklist_lock
);
637 * We found no owner yet mm_users > 1: this implies that we are
638 * most likely racing with swapoff (try_to_unuse()) or /proc or
639 * ptrace or page migration (get_task_mm()). Mark owner as NULL,
640 * so that subsystems can understand the callback and take action.
642 down_write(&mm
->mmap_sem
);
643 cgroup_mm_owner_callbacks(mm
->owner
, NULL
);
645 up_write(&mm
->mmap_sem
);
651 read_unlock(&tasklist_lock
);
652 down_write(&mm
->mmap_sem
);
654 * The task_lock protects c->mm from changing.
655 * We always want mm->owner->mm == mm
660 up_write(&mm
->mmap_sem
);
664 cgroup_mm_owner_callbacks(mm
->owner
, c
);
667 up_write(&mm
->mmap_sem
);
670 #endif /* CONFIG_MM_OWNER */
673 * Turn us into a lazy TLB process if we
676 static void exit_mm(struct task_struct
* tsk
)
678 struct mm_struct
*mm
= tsk
->mm
;
679 struct core_state
*core_state
;
685 * Serialize with any possible pending coredump.
686 * We must hold mmap_sem around checking core_state
687 * and clearing tsk->mm. The core-inducing thread
688 * will increment ->nr_threads for each thread in the
689 * group with ->mm != NULL.
691 down_read(&mm
->mmap_sem
);
692 core_state
= mm
->core_state
;
694 struct core_thread self
;
695 up_read(&mm
->mmap_sem
);
698 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
700 * Implies mb(), the result of xchg() must be visible
701 * to core_state->dumper.
703 if (atomic_dec_and_test(&core_state
->nr_threads
))
704 complete(&core_state
->startup
);
707 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
708 if (!self
.task
) /* see coredump_finish() */
712 __set_task_state(tsk
, TASK_RUNNING
);
713 down_read(&mm
->mmap_sem
);
715 atomic_inc(&mm
->mm_count
);
716 BUG_ON(mm
!= tsk
->active_mm
);
717 /* more a memory barrier than a real lock */
720 up_read(&mm
->mmap_sem
);
721 enter_lazy_tlb(mm
, current
);
722 /* We don't want this task to be frozen prematurely */
723 clear_freeze_flag(tsk
);
725 mm_update_next_owner(mm
);
730 * Return nonzero if @parent's children should reap themselves.
732 * Called with write_lock_irq(&tasklist_lock) held.
734 static int ignoring_children(struct task_struct
*parent
)
737 struct sighand_struct
*psig
= parent
->sighand
;
739 spin_lock_irqsave(&psig
->siglock
, flags
);
740 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
741 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
742 spin_unlock_irqrestore(&psig
->siglock
, flags
);
747 * Detach all tasks we were using ptrace on.
748 * Any that need to be release_task'd are put on the @dead list.
750 * Called with write_lock(&tasklist_lock) held.
752 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
754 struct task_struct
*p
, *n
;
757 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
760 if (p
->exit_state
!= EXIT_ZOMBIE
)
764 * If it's a zombie, our attachedness prevented normal
765 * parent notification or self-reaping. Do notification
766 * now if it would have happened earlier. If it should
767 * reap itself, add it to the @dead list. We can't call
768 * release_task() here because we already hold tasklist_lock.
770 * If it's our own child, there is no notification to do.
771 * But if our normal children self-reap, then this child
772 * was prevented by ptrace and we must reap it now.
774 if (!task_detached(p
) && thread_group_empty(p
)) {
775 if (!same_thread_group(p
->real_parent
, parent
))
776 do_notify_parent(p
, p
->exit_signal
);
779 ign
= ignoring_children(parent
);
785 if (task_detached(p
)) {
787 * Mark it as in the process of being reaped.
789 p
->exit_state
= EXIT_DEAD
;
790 list_add(&p
->ptrace_entry
, dead
);
796 * Finish up exit-time ptrace cleanup.
798 * Called without locks.
800 static void ptrace_exit_finish(struct task_struct
*parent
,
801 struct list_head
*dead
)
803 struct task_struct
*p
, *n
;
805 BUG_ON(!list_empty(&parent
->ptraced
));
807 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
808 list_del_init(&p
->ptrace_entry
);
813 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
815 if (p
->pdeath_signal
)
816 /* We already hold the tasklist_lock here. */
817 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
819 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
821 /* If this is a threaded reparent there is no need to
822 * notify anyone anything has happened.
824 if (same_thread_group(p
->real_parent
, father
))
827 /* We don't want people slaying init. */
828 if (!task_detached(p
))
829 p
->exit_signal
= SIGCHLD
;
831 /* If we'd notified the old parent about this child's death,
832 * also notify the new parent.
834 if (!ptrace_reparented(p
) &&
835 p
->exit_state
== EXIT_ZOMBIE
&&
836 !task_detached(p
) && thread_group_empty(p
))
837 do_notify_parent(p
, p
->exit_signal
);
839 kill_orphaned_pgrp(p
, father
);
843 * When we die, we re-parent all our children.
844 * Try to give them to another thread in our thread
845 * group, and if no such member exists, give it to
846 * the child reaper process (ie "init") in our pid
849 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
851 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
852 struct task_struct
*thread
;
855 while_each_thread(father
, thread
) {
856 if (thread
->flags
& PF_EXITING
)
858 if (unlikely(pid_ns
->child_reaper
== father
))
859 pid_ns
->child_reaper
= thread
;
863 if (unlikely(pid_ns
->child_reaper
== father
)) {
864 write_unlock_irq(&tasklist_lock
);
865 if (unlikely(pid_ns
== &init_pid_ns
))
866 panic("Attempted to kill init!");
868 zap_pid_ns_processes(pid_ns
);
869 write_lock_irq(&tasklist_lock
);
871 * We can not clear ->child_reaper or leave it alone.
872 * There may by stealth EXIT_DEAD tasks on ->children,
873 * forget_original_parent() must move them somewhere.
875 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
878 return pid_ns
->child_reaper
;
881 static void forget_original_parent(struct task_struct
*father
)
883 struct task_struct
*p
, *n
, *reaper
;
884 LIST_HEAD(ptrace_dead
);
886 write_lock_irq(&tasklist_lock
);
887 reaper
= find_new_reaper(father
);
889 * First clean up ptrace if we were using it.
891 ptrace_exit(father
, &ptrace_dead
);
893 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
894 p
->real_parent
= reaper
;
895 if (p
->parent
== father
) {
897 p
->parent
= p
->real_parent
;
899 reparent_thread(p
, father
);
902 write_unlock_irq(&tasklist_lock
);
903 BUG_ON(!list_empty(&father
->children
));
905 ptrace_exit_finish(father
, &ptrace_dead
);
909 * Send signals to all our closest relatives so that they know
910 * to properly mourn us..
912 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
918 * This does two things:
920 * A. Make init inherit all the child processes
921 * B. Check to see if any process groups have become orphaned
922 * as a result of our exiting, and if they have any stopped
923 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
925 forget_original_parent(tsk
);
926 exit_task_namespaces(tsk
);
928 write_lock_irq(&tasklist_lock
);
930 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
932 /* Let father know we died
934 * Thread signals are configurable, but you aren't going to use
935 * that to send signals to arbitary processes.
936 * That stops right now.
938 * If the parent exec id doesn't match the exec id we saved
939 * when we started then we know the parent has changed security
942 * If our self_exec id doesn't match our parent_exec_id then
943 * we have changed execution domain as these two values started
944 * the same after a fork.
946 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
947 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
948 tsk
->self_exec_id
!= tsk
->parent_exec_id
) &&
950 tsk
->exit_signal
= SIGCHLD
;
952 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
954 signal
= do_notify_parent(tsk
, signal
);
956 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
958 /* mt-exec, de_thread() is waiting for us */
959 if (thread_group_leader(tsk
) &&
960 tsk
->signal
->group_exit_task
&&
961 tsk
->signal
->notify_count
< 0)
962 wake_up_process(tsk
->signal
->group_exit_task
);
964 write_unlock_irq(&tasklist_lock
);
966 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
968 /* If the process is dead, release it - nobody will wait for it */
969 if (signal
== DEATH_REAP
)
973 #ifdef CONFIG_DEBUG_STACK_USAGE
974 static void check_stack_usage(void)
976 static DEFINE_SPINLOCK(low_water_lock
);
977 static int lowest_to_date
= THREAD_SIZE
;
978 unsigned long *n
= end_of_stack(current
);
983 free
= (unsigned long)n
- (unsigned long)end_of_stack(current
);
985 if (free
>= lowest_to_date
)
988 spin_lock(&low_water_lock
);
989 if (free
< lowest_to_date
) {
990 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
992 current
->comm
, free
);
993 lowest_to_date
= free
;
995 spin_unlock(&low_water_lock
);
998 static inline void check_stack_usage(void) {}
1001 NORET_TYPE
void do_exit(long code
)
1003 struct task_struct
*tsk
= current
;
1006 profile_task_exit(tsk
);
1008 WARN_ON(atomic_read(&tsk
->fs_excl
));
1010 if (unlikely(in_interrupt()))
1011 panic("Aiee, killing interrupt handler!");
1012 if (unlikely(!tsk
->pid
))
1013 panic("Attempted to kill the idle task!");
1015 tracehook_report_exit(&code
);
1018 * We're taking recursive faults here in do_exit. Safest is to just
1019 * leave this task alone and wait for reboot.
1021 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1023 "Fixing recursive fault but reboot is needed!\n");
1025 * We can do this unlocked here. The futex code uses
1026 * this flag just to verify whether the pi state
1027 * cleanup has been done or not. In the worst case it
1028 * loops once more. We pretend that the cleanup was
1029 * done as there is no way to return. Either the
1030 * OWNER_DIED bit is set by now or we push the blocked
1031 * task into the wait for ever nirwana as well.
1033 tsk
->flags
|= PF_EXITPIDONE
;
1034 if (tsk
->io_context
)
1036 set_current_state(TASK_UNINTERRUPTIBLE
);
1040 exit_signals(tsk
); /* sets PF_EXITING */
1042 * tsk->flags are checked in the futex code to protect against
1043 * an exiting task cleaning up the robust pi futexes.
1046 spin_unlock_wait(&tsk
->pi_lock
);
1048 if (unlikely(in_atomic()))
1049 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1050 current
->comm
, task_pid_nr(current
),
1053 acct_update_integrals(tsk
);
1055 update_hiwater_rss(tsk
->mm
);
1056 update_hiwater_vm(tsk
->mm
);
1058 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1060 hrtimer_cancel(&tsk
->signal
->real_timer
);
1061 exit_itimers(tsk
->signal
);
1063 acct_collect(code
, group_dead
);
1066 if (unlikely(tsk
->audit_context
))
1069 tsk
->exit_code
= code
;
1070 taskstats_exit(tsk
, group_dead
);
1076 trace_sched_process_exit(tsk
);
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
;
1100 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1101 exit_pi_state_list(tsk
);
1102 if (unlikely(current
->pi_state_cache
))
1103 kfree(current
->pi_state_cache
);
1106 * Make sure we are holding no locks:
1108 debug_check_no_locks_held(tsk
);
1110 * We can do this unlocked here. The futex code uses this flag
1111 * just to verify whether the pi state cleanup has been done
1112 * or not. In the worst case it loops once more.
1114 tsk
->flags
|= PF_EXITPIDONE
;
1116 if (tsk
->io_context
)
1119 if (tsk
->splice_pipe
)
1120 __free_pipe_info(tsk
->splice_pipe
);
1123 /* causes final put_task_struct in finish_task_switch(). */
1124 tsk
->state
= TASK_DEAD
;
1128 /* Avoid "noreturn function does return". */
1130 cpu_relax(); /* For when BUG is null */
1133 EXPORT_SYMBOL_GPL(do_exit
);
1135 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1143 EXPORT_SYMBOL(complete_and_exit
);
1145 asmlinkage
long sys_exit(int error_code
)
1147 do_exit((error_code
&0xff)<<8);
1151 * Take down every thread in the group. This is called by fatal signals
1152 * as well as by sys_exit_group (below).
1155 do_group_exit(int exit_code
)
1157 struct signal_struct
*sig
= current
->signal
;
1159 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1161 if (signal_group_exit(sig
))
1162 exit_code
= sig
->group_exit_code
;
1163 else if (!thread_group_empty(current
)) {
1164 struct sighand_struct
*const sighand
= current
->sighand
;
1165 spin_lock_irq(&sighand
->siglock
);
1166 if (signal_group_exit(sig
))
1167 /* Another thread got here before we took the lock. */
1168 exit_code
= sig
->group_exit_code
;
1170 sig
->group_exit_code
= exit_code
;
1171 sig
->flags
= SIGNAL_GROUP_EXIT
;
1172 zap_other_threads(current
);
1174 spin_unlock_irq(&sighand
->siglock
);
1182 * this kills every thread in the thread group. Note that any externally
1183 * wait4()-ing process will get the correct exit code - even if this
1184 * thread is not the thread group leader.
1186 asmlinkage
void sys_exit_group(int error_code
)
1188 do_group_exit((error_code
& 0xff) << 8);
1191 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1193 struct pid
*pid
= NULL
;
1194 if (type
== PIDTYPE_PID
)
1195 pid
= task
->pids
[type
].pid
;
1196 else if (type
< PIDTYPE_MAX
)
1197 pid
= task
->group_leader
->pids
[type
].pid
;
1201 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1202 struct task_struct
*p
)
1206 if (type
< PIDTYPE_MAX
) {
1207 if (task_pid_type(p
, type
) != pid
)
1211 /* Wait for all children (clone and not) if __WALL is set;
1212 * otherwise, wait for clone children *only* if __WCLONE is
1213 * set; otherwise, wait for non-clone children *only*. (Note:
1214 * A "clone" child here is one that reports to its parent
1215 * using a signal other than SIGCHLD.) */
1216 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1217 && !(options
& __WALL
))
1220 err
= security_task_wait(p
);
1227 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1228 int why
, int status
,
1229 struct siginfo __user
*infop
,
1230 struct rusage __user
*rusagep
)
1232 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1236 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1238 retval
= put_user(0, &infop
->si_errno
);
1240 retval
= put_user((short)why
, &infop
->si_code
);
1242 retval
= put_user(pid
, &infop
->si_pid
);
1244 retval
= put_user(uid
, &infop
->si_uid
);
1246 retval
= put_user(status
, &infop
->si_status
);
1253 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1254 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1255 * the lock and this task is uninteresting. If we return nonzero, we have
1256 * released the lock and the system call should return.
1258 static int wait_task_zombie(struct task_struct
*p
, int options
,
1259 struct siginfo __user
*infop
,
1260 int __user
*stat_addr
, struct rusage __user
*ru
)
1262 unsigned long state
;
1263 int retval
, status
, traced
;
1264 pid_t pid
= task_pid_vnr(p
);
1266 if (!likely(options
& WEXITED
))
1269 if (unlikely(options
& WNOWAIT
)) {
1271 int exit_code
= p
->exit_code
;
1275 read_unlock(&tasklist_lock
);
1276 if ((exit_code
& 0x7f) == 0) {
1278 status
= exit_code
>> 8;
1280 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1281 status
= exit_code
& 0x7f;
1283 return wait_noreap_copyout(p
, pid
, uid
, why
,
1288 * Try to move the task's state to DEAD
1289 * only one thread is allowed to do this:
1291 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1292 if (state
!= EXIT_ZOMBIE
) {
1293 BUG_ON(state
!= EXIT_DEAD
);
1297 traced
= ptrace_reparented(p
);
1299 if (likely(!traced
)) {
1300 struct signal_struct
*psig
;
1301 struct signal_struct
*sig
;
1302 struct task_cputime cputime
;
1305 * The resource counters for the group leader are in its
1306 * own task_struct. Those for dead threads in the group
1307 * are in its signal_struct, as are those for the child
1308 * processes it has previously reaped. All these
1309 * accumulate in the parent's signal_struct c* fields.
1311 * We don't bother to take a lock here to protect these
1312 * p->signal fields, because they are only touched by
1313 * __exit_signal, which runs with tasklist_lock
1314 * write-locked anyway, and so is excluded here. We do
1315 * need to protect the access to p->parent->signal fields,
1316 * as other threads in the parent group can be right
1317 * here reaping other children at the same time.
1319 * We use thread_group_cputime() to get times for the thread
1320 * group, which consolidates times for all threads in the
1321 * group including the group leader.
1323 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1324 psig
= p
->parent
->signal
;
1326 thread_group_cputime(p
, &cputime
);
1328 cputime_add(psig
->cutime
,
1329 cputime_add(cputime
.utime
,
1332 cputime_add(psig
->cstime
,
1333 cputime_add(cputime
.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 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1355 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1356 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1360 * Now we are sure this task is interesting, and no other
1361 * thread can reap it because we set its state to EXIT_DEAD.
1363 read_unlock(&tasklist_lock
);
1366 * Flush inherited counters to the parent - before the parent
1367 * gets woken up by child-exit notifications.
1369 perf_counter_exit_task(p
);
1371 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1372 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1373 ? p
->signal
->group_exit_code
: p
->exit_code
;
1374 if (!retval
&& stat_addr
)
1375 retval
= put_user(status
, stat_addr
);
1376 if (!retval
&& infop
)
1377 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1378 if (!retval
&& infop
)
1379 retval
= put_user(0, &infop
->si_errno
);
1380 if (!retval
&& infop
) {
1383 if ((status
& 0x7f) == 0) {
1387 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1390 retval
= put_user((short)why
, &infop
->si_code
);
1392 retval
= put_user(status
, &infop
->si_status
);
1394 if (!retval
&& infop
)
1395 retval
= put_user(pid
, &infop
->si_pid
);
1396 if (!retval
&& infop
)
1397 retval
= put_user(p
->uid
, &infop
->si_uid
);
1402 write_lock_irq(&tasklist_lock
);
1403 /* We dropped tasklist, ptracer could die and untrace */
1406 * If this is not a detached task, notify the parent.
1407 * If it's still not detached after that, don't release
1410 if (!task_detached(p
)) {
1411 do_notify_parent(p
, p
->exit_signal
);
1412 if (!task_detached(p
)) {
1413 p
->exit_state
= EXIT_ZOMBIE
;
1417 write_unlock_irq(&tasklist_lock
);
1426 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1427 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1428 * the lock and this task is uninteresting. If we return nonzero, we have
1429 * released the lock and the system call should return.
1431 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1432 int options
, struct siginfo __user
*infop
,
1433 int __user
*stat_addr
, struct rusage __user
*ru
)
1435 int retval
, exit_code
, why
;
1436 uid_t uid
= 0; /* unneeded, required by compiler */
1439 if (!(options
& WUNTRACED
))
1443 spin_lock_irq(&p
->sighand
->siglock
);
1445 if (unlikely(!task_is_stopped_or_traced(p
)))
1448 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1450 * A group stop is in progress and this is the group leader.
1451 * We won't report until all threads have stopped.
1455 exit_code
= p
->exit_code
;
1459 if (!unlikely(options
& WNOWAIT
))
1464 spin_unlock_irq(&p
->sighand
->siglock
);
1469 * Now we are pretty sure this task is interesting.
1470 * Make sure it doesn't get reaped out from under us while we
1471 * give up the lock and then examine it below. We don't want to
1472 * keep holding onto the tasklist_lock while we call getrusage and
1473 * possibly take page faults for user memory.
1476 pid
= task_pid_vnr(p
);
1477 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1478 read_unlock(&tasklist_lock
);
1480 if (unlikely(options
& WNOWAIT
))
1481 return wait_noreap_copyout(p
, pid
, uid
,
1485 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1486 if (!retval
&& stat_addr
)
1487 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1488 if (!retval
&& infop
)
1489 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1490 if (!retval
&& infop
)
1491 retval
= put_user(0, &infop
->si_errno
);
1492 if (!retval
&& infop
)
1493 retval
= put_user((short)why
, &infop
->si_code
);
1494 if (!retval
&& infop
)
1495 retval
= put_user(exit_code
, &infop
->si_status
);
1496 if (!retval
&& infop
)
1497 retval
= put_user(pid
, &infop
->si_pid
);
1498 if (!retval
&& infop
)
1499 retval
= put_user(uid
, &infop
->si_uid
);
1509 * Handle do_wait work for one task in a live, non-stopped state.
1510 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1511 * the lock and this task is uninteresting. If we return nonzero, we have
1512 * released the lock and the system call should return.
1514 static int wait_task_continued(struct task_struct
*p
, int options
,
1515 struct siginfo __user
*infop
,
1516 int __user
*stat_addr
, struct rusage __user
*ru
)
1522 if (!unlikely(options
& WCONTINUED
))
1525 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1528 spin_lock_irq(&p
->sighand
->siglock
);
1529 /* Re-check with the lock held. */
1530 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1531 spin_unlock_irq(&p
->sighand
->siglock
);
1534 if (!unlikely(options
& WNOWAIT
))
1535 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1536 spin_unlock_irq(&p
->sighand
->siglock
);
1538 pid
= task_pid_vnr(p
);
1541 read_unlock(&tasklist_lock
);
1544 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1546 if (!retval
&& stat_addr
)
1547 retval
= put_user(0xffff, stat_addr
);
1551 retval
= wait_noreap_copyout(p
, pid
, uid
,
1552 CLD_CONTINUED
, SIGCONT
,
1554 BUG_ON(retval
== 0);
1561 * Consider @p for a wait by @parent.
1563 * -ECHILD should be in *@notask_error before the first call.
1564 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1565 * Returns zero if the search for a child should continue;
1566 * then *@notask_error is 0 if @p is an eligible child,
1567 * or another error from security_task_wait(), or still -ECHILD.
1569 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1570 struct task_struct
*p
, int *notask_error
,
1571 enum pid_type type
, struct pid
*pid
, int options
,
1572 struct siginfo __user
*infop
,
1573 int __user
*stat_addr
, struct rusage __user
*ru
)
1575 int ret
= eligible_child(type
, pid
, options
, p
);
1579 if (unlikely(ret
< 0)) {
1581 * If we have not yet seen any eligible child,
1582 * then let this error code replace -ECHILD.
1583 * A permission error will give the user a clue
1584 * to look for security policy problems, rather
1585 * than for mysterious wait bugs.
1588 *notask_error
= ret
;
1591 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1593 * This child is hidden by ptrace.
1594 * We aren't allowed to see it now, but eventually we will.
1600 if (p
->exit_state
== EXIT_DEAD
)
1604 * We don't reap group leaders with subthreads.
1606 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1607 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1610 * It's stopped or running now, so it might
1611 * later continue, exit, or stop again.
1615 if (task_is_stopped_or_traced(p
))
1616 return wait_task_stopped(ptrace
, p
, options
,
1617 infop
, stat_addr
, ru
);
1619 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1623 * Do the work of do_wait() for one thread in the group, @tsk.
1625 * -ECHILD should be in *@notask_error before the first call.
1626 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1627 * Returns zero if the search for a child should continue; then
1628 * *@notask_error is 0 if there were any eligible children,
1629 * or another error from security_task_wait(), or still -ECHILD.
1631 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1632 enum pid_type type
, struct pid
*pid
, int options
,
1633 struct siginfo __user
*infop
, int __user
*stat_addr
,
1634 struct rusage __user
*ru
)
1636 struct task_struct
*p
;
1638 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1640 * Do not consider detached threads.
1642 if (!task_detached(p
)) {
1643 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1645 infop
, stat_addr
, ru
);
1654 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1655 enum pid_type type
, struct pid
*pid
, int options
,
1656 struct siginfo __user
*infop
, int __user
*stat_addr
,
1657 struct rusage __user
*ru
)
1659 struct task_struct
*p
;
1662 * Traditionally we see ptrace'd stopped tasks regardless of options.
1664 options
|= WUNTRACED
;
1666 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1667 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1669 infop
, stat_addr
, ru
);
1677 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1678 struct siginfo __user
*infop
, int __user
*stat_addr
,
1679 struct rusage __user
*ru
)
1681 DECLARE_WAITQUEUE(wait
, current
);
1682 struct task_struct
*tsk
;
1685 trace_sched_process_wait(pid
);
1687 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1690 * If there is nothing that can match our critiera just get out.
1691 * We will clear @retval to zero if we see any child that might later
1692 * match our criteria, even if we are not able to reap it yet.
1695 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1698 current
->state
= TASK_INTERRUPTIBLE
;
1699 read_lock(&tasklist_lock
);
1702 int tsk_result
= do_wait_thread(tsk
, &retval
,
1704 infop
, stat_addr
, ru
);
1706 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1708 infop
, stat_addr
, ru
);
1711 * tasklist_lock is unlocked and we have a final result.
1713 retval
= tsk_result
;
1717 if (options
& __WNOTHREAD
)
1719 tsk
= next_thread(tsk
);
1720 BUG_ON(tsk
->signal
!= current
->signal
);
1721 } while (tsk
!= current
);
1722 read_unlock(&tasklist_lock
);
1724 if (!retval
&& !(options
& WNOHANG
)) {
1725 retval
= -ERESTARTSYS
;
1726 if (!signal_pending(current
)) {
1733 current
->state
= TASK_RUNNING
;
1734 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1740 * For a WNOHANG return, clear out all the fields
1741 * we would set so the user can easily tell the
1745 retval
= put_user(0, &infop
->si_signo
);
1747 retval
= put_user(0, &infop
->si_errno
);
1749 retval
= put_user(0, &infop
->si_code
);
1751 retval
= put_user(0, &infop
->si_pid
);
1753 retval
= put_user(0, &infop
->si_uid
);
1755 retval
= put_user(0, &infop
->si_status
);
1761 asmlinkage
long sys_waitid(int which
, pid_t upid
,
1762 struct siginfo __user
*infop
, int options
,
1763 struct rusage __user
*ru
)
1765 struct pid
*pid
= NULL
;
1769 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1771 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1784 type
= PIDTYPE_PGID
;
1792 if (type
< PIDTYPE_MAX
)
1793 pid
= find_get_pid(upid
);
1794 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1797 /* avoid REGPARM breakage on x86: */
1798 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1802 asmlinkage
long sys_wait4(pid_t upid
, int __user
*stat_addr
,
1803 int options
, struct rusage __user
*ru
)
1805 struct pid
*pid
= NULL
;
1809 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1810 __WNOTHREAD
|__WCLONE
|__WALL
))
1815 else if (upid
< 0) {
1816 type
= PIDTYPE_PGID
;
1817 pid
= find_get_pid(-upid
);
1818 } else if (upid
== 0) {
1819 type
= PIDTYPE_PGID
;
1820 pid
= get_pid(task_pgrp(current
));
1821 } else /* upid > 0 */ {
1823 pid
= find_get_pid(upid
);
1826 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1829 /* avoid REGPARM breakage on x86: */
1830 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1834 #ifdef __ARCH_WANT_SYS_WAITPID
1837 * sys_waitpid() remains for compatibility. waitpid() should be
1838 * implemented by calling sys_wait4() from libc.a.
1840 asmlinkage
long sys_waitpid(pid_t pid
, int __user
*stat_addr
, int options
)
1842 return sys_wait4(pid
, stat_addr
, options
, NULL
);
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