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/init_task.h>
50 #include <trace/sched.h>
52 #include <asm/uaccess.h>
53 #include <asm/unistd.h>
54 #include <asm/pgtable.h>
55 #include <asm/mmu_context.h>
56 #include "cred-internals.h"
58 DEFINE_TRACE(sched_process_free
);
59 DEFINE_TRACE(sched_process_exit
);
60 DEFINE_TRACE(sched_process_wait
);
62 static void exit_mm(struct task_struct
* tsk
);
64 static inline int task_detached(struct task_struct
*p
)
66 return p
->exit_signal
== -1;
69 static void __unhash_process(struct task_struct
*p
)
72 detach_pid(p
, PIDTYPE_PID
);
73 if (thread_group_leader(p
)) {
74 detach_pid(p
, PIDTYPE_PGID
);
75 detach_pid(p
, PIDTYPE_SID
);
77 list_del_rcu(&p
->tasks
);
78 __get_cpu_var(process_counts
)--;
80 list_del_rcu(&p
->thread_group
);
81 list_del_init(&p
->sibling
);
85 * This function expects the tasklist_lock write-locked.
87 static void __exit_signal(struct task_struct
*tsk
)
89 struct signal_struct
*sig
= tsk
->signal
;
90 struct sighand_struct
*sighand
;
93 BUG_ON(!atomic_read(&sig
->count
));
95 sighand
= rcu_dereference(tsk
->sighand
);
96 spin_lock(&sighand
->siglock
);
98 posix_cpu_timers_exit(tsk
);
99 if (atomic_dec_and_test(&sig
->count
))
100 posix_cpu_timers_exit_group(tsk
);
103 * If there is any task waiting for the group exit
106 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
107 wake_up_process(sig
->group_exit_task
);
109 if (tsk
== sig
->curr_target
)
110 sig
->curr_target
= next_thread(tsk
);
112 * Accumulate here the counters for all threads but the
113 * group leader as they die, so they can be added into
114 * the process-wide totals when those are taken.
115 * The group leader stays around as a zombie as long
116 * as there are other threads. When it gets reaped,
117 * the exit.c code will add its counts into these totals.
118 * We won't ever get here for the group leader, since it
119 * will have been the last reference on the signal_struct.
121 sig
->utime
= cputime_add(sig
->utime
, task_utime(tsk
));
122 sig
->stime
= cputime_add(sig
->stime
, task_stime(tsk
));
123 sig
->gtime
= cputime_add(sig
->gtime
, task_gtime(tsk
));
124 sig
->min_flt
+= tsk
->min_flt
;
125 sig
->maj_flt
+= tsk
->maj_flt
;
126 sig
->nvcsw
+= tsk
->nvcsw
;
127 sig
->nivcsw
+= tsk
->nivcsw
;
128 sig
->inblock
+= task_io_get_inblock(tsk
);
129 sig
->oublock
+= task_io_get_oublock(tsk
);
130 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
131 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
132 sig
= NULL
; /* Marker for below. */
135 __unhash_process(tsk
);
138 * Do this under ->siglock, we can race with another thread
139 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
141 flush_sigqueue(&tsk
->pending
);
145 spin_unlock(&sighand
->siglock
);
147 __cleanup_sighand(sighand
);
148 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
150 flush_sigqueue(&sig
->shared_pending
);
151 taskstats_tgid_free(sig
);
153 * Make sure ->signal can't go away under rq->lock,
154 * see account_group_exec_runtime().
156 task_rq_unlock_wait(tsk
);
157 __cleanup_signal(sig
);
161 static void delayed_put_task_struct(struct rcu_head
*rhp
)
163 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
165 trace_sched_process_free(tsk
);
166 put_task_struct(tsk
);
170 void release_task(struct task_struct
* p
)
172 struct task_struct
*leader
;
175 tracehook_prepare_release_task(p
);
176 /* don't need to get the RCU readlock here - the process is dead and
177 * can't be modifying its own credentials */
178 atomic_dec(&__task_cred(p
)->user
->processes
);
181 write_lock_irq(&tasklist_lock
);
182 tracehook_finish_release_task(p
);
186 * If we are the last non-leader member of the thread
187 * group, and the leader is zombie, then notify the
188 * group leader's parent process. (if it wants notification.)
191 leader
= p
->group_leader
;
192 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
193 BUG_ON(task_detached(leader
));
194 do_notify_parent(leader
, leader
->exit_signal
);
196 * If we were the last child thread and the leader has
197 * exited already, and the leader's parent ignores SIGCHLD,
198 * then we are the one who should release the leader.
200 * do_notify_parent() will have marked it self-reaping in
203 zap_leader
= task_detached(leader
);
206 * This maintains the invariant that release_task()
207 * only runs on a task in EXIT_DEAD, just for sanity.
210 leader
->exit_state
= EXIT_DEAD
;
213 write_unlock_irq(&tasklist_lock
);
215 call_rcu(&p
->rcu
, delayed_put_task_struct
);
218 if (unlikely(zap_leader
))
223 * This checks not only the pgrp, but falls back on the pid if no
224 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
227 * The caller must hold rcu lock or the tasklist lock.
229 struct pid
*session_of_pgrp(struct pid
*pgrp
)
231 struct task_struct
*p
;
232 struct pid
*sid
= NULL
;
234 p
= pid_task(pgrp
, PIDTYPE_PGID
);
236 p
= pid_task(pgrp
, PIDTYPE_PID
);
238 sid
= task_session(p
);
244 * Determine if a process group is "orphaned", according to the POSIX
245 * definition in 2.2.2.52. Orphaned process groups are not to be affected
246 * by terminal-generated stop signals. Newly orphaned process groups are
247 * to receive a SIGHUP and a SIGCONT.
249 * "I ask you, have you ever known what it is to be an orphan?"
251 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
253 struct task_struct
*p
;
255 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
256 if ((p
== ignored_task
) ||
257 (p
->exit_state
&& thread_group_empty(p
)) ||
258 is_global_init(p
->real_parent
))
261 if (task_pgrp(p
->real_parent
) != pgrp
&&
262 task_session(p
->real_parent
) == task_session(p
))
264 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
269 int is_current_pgrp_orphaned(void)
273 read_lock(&tasklist_lock
);
274 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
275 read_unlock(&tasklist_lock
);
280 static int has_stopped_jobs(struct pid
*pgrp
)
283 struct task_struct
*p
;
285 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
286 if (!task_is_stopped(p
))
290 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
295 * Check to see if any process groups have become orphaned as
296 * a result of our exiting, and if they have any stopped jobs,
297 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
300 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
302 struct pid
*pgrp
= task_pgrp(tsk
);
303 struct task_struct
*ignored_task
= tsk
;
306 /* exit: our father is in a different pgrp than
307 * we are and we were the only connection outside.
309 parent
= tsk
->real_parent
;
311 /* reparent: our child is in a different pgrp than
312 * we are, and it was the only connection outside.
316 if (task_pgrp(parent
) != pgrp
&&
317 task_session(parent
) == task_session(tsk
) &&
318 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
319 has_stopped_jobs(pgrp
)) {
320 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
321 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
326 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
328 * If a kernel thread is launched as a result of a system call, or if
329 * it ever exits, it should generally reparent itself to kthreadd so it
330 * isn't in the way of other processes and is correctly cleaned up on exit.
332 * The various task state such as scheduling policy and priority may have
333 * been inherited from a user process, so we reset them to sane values here.
335 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
337 static void reparent_to_kthreadd(void)
339 write_lock_irq(&tasklist_lock
);
341 ptrace_unlink(current
);
342 /* Reparent to init */
343 current
->real_parent
= current
->parent
= kthreadd_task
;
344 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
346 /* Set the exit signal to SIGCHLD so we signal init on exit */
347 current
->exit_signal
= SIGCHLD
;
349 if (task_nice(current
) < 0)
350 set_user_nice(current
, 0);
354 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
355 sizeof(current
->signal
->rlim
));
357 atomic_inc(&init_cred
.usage
);
358 commit_creds(&init_cred
);
359 write_unlock_irq(&tasklist_lock
);
362 void __set_special_pids(struct pid
*pid
)
364 struct task_struct
*curr
= current
->group_leader
;
365 pid_t nr
= pid_nr(pid
);
367 if (task_session(curr
) != pid
) {
368 change_pid(curr
, PIDTYPE_SID
, pid
);
369 set_task_session(curr
, nr
);
371 if (task_pgrp(curr
) != pid
) {
372 change_pid(curr
, PIDTYPE_PGID
, pid
);
373 set_task_pgrp(curr
, nr
);
377 static void set_special_pids(struct pid
*pid
)
379 write_lock_irq(&tasklist_lock
);
380 __set_special_pids(pid
);
381 write_unlock_irq(&tasklist_lock
);
385 * Let kernel threads use this to say that they
386 * allow a certain signal (since daemonize() will
387 * have disabled all of them by default).
389 int allow_signal(int sig
)
391 if (!valid_signal(sig
) || sig
< 1)
394 spin_lock_irq(¤t
->sighand
->siglock
);
395 sigdelset(¤t
->blocked
, sig
);
397 /* Kernel threads handle their own signals.
398 Let the signal code know it'll be handled, so
399 that they don't get converted to SIGKILL or
400 just silently dropped */
401 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
404 spin_unlock_irq(¤t
->sighand
->siglock
);
408 EXPORT_SYMBOL(allow_signal
);
410 int disallow_signal(int sig
)
412 if (!valid_signal(sig
) || sig
< 1)
415 spin_lock_irq(¤t
->sighand
->siglock
);
416 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
418 spin_unlock_irq(¤t
->sighand
->siglock
);
422 EXPORT_SYMBOL(disallow_signal
);
425 * Put all the gunge required to become a kernel thread without
426 * attached user resources in one place where it belongs.
429 void daemonize(const char *name
, ...)
432 struct fs_struct
*fs
;
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 exit_fs(current
); /* current->fs->count--; */
468 atomic_inc(&fs
->count
);
471 current
->files
= init_task
.files
;
472 atomic_inc(¤t
->files
->count
);
474 reparent_to_kthreadd();
477 EXPORT_SYMBOL(daemonize
);
479 static void close_files(struct files_struct
* files
)
487 * It is safe to dereference the fd table without RCU or
488 * ->file_lock because this is the last reference to the
491 fdt
= files_fdtable(files
);
495 if (i
>= fdt
->max_fds
)
497 set
= fdt
->open_fds
->fds_bits
[j
++];
500 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
502 filp_close(file
, files
);
512 struct files_struct
*get_files_struct(struct task_struct
*task
)
514 struct files_struct
*files
;
519 atomic_inc(&files
->count
);
525 void put_files_struct(struct files_struct
*files
)
529 if (atomic_dec_and_test(&files
->count
)) {
532 * Free the fd and fdset arrays if we expanded them.
533 * If the fdtable was embedded, pass files for freeing
534 * at the end of the RCU grace period. Otherwise,
535 * you can free files immediately.
537 fdt
= files_fdtable(files
);
538 if (fdt
!= &files
->fdtab
)
539 kmem_cache_free(files_cachep
, files
);
544 void reset_files_struct(struct files_struct
*files
)
546 struct task_struct
*tsk
= current
;
547 struct files_struct
*old
;
553 put_files_struct(old
);
556 void exit_files(struct task_struct
*tsk
)
558 struct files_struct
* files
= tsk
->files
;
564 put_files_struct(files
);
568 void put_fs_struct(struct fs_struct
*fs
)
570 /* No need to hold fs->lock if we are killing it */
571 if (atomic_dec_and_test(&fs
->count
)) {
574 kmem_cache_free(fs_cachep
, fs
);
578 void exit_fs(struct task_struct
*tsk
)
580 struct fs_struct
* fs
= tsk
->fs
;
590 EXPORT_SYMBOL_GPL(exit_fs
);
592 #ifdef CONFIG_MM_OWNER
594 * Task p is exiting and it owned mm, lets find a new owner for it
597 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
600 * If there are other users of the mm and the owner (us) is exiting
601 * we need to find a new owner to take on the responsibility.
603 if (atomic_read(&mm
->mm_users
) <= 1)
610 void mm_update_next_owner(struct mm_struct
*mm
)
612 struct task_struct
*c
, *g
, *p
= current
;
615 if (!mm_need_new_owner(mm
, p
))
618 read_lock(&tasklist_lock
);
620 * Search in the children
622 list_for_each_entry(c
, &p
->children
, sibling
) {
624 goto assign_new_owner
;
628 * Search in the siblings
630 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
632 goto assign_new_owner
;
636 * Search through everything else. We should not get
639 do_each_thread(g
, c
) {
641 goto assign_new_owner
;
642 } while_each_thread(g
, c
);
644 read_unlock(&tasklist_lock
);
646 * We found no owner yet mm_users > 1: this implies that we are
647 * most likely racing with swapoff (try_to_unuse()) or /proc or
648 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
657 * The task_lock protects c->mm from changing.
658 * We always want mm->owner->mm == mm
662 * Delay read_unlock() till we have the task_lock()
663 * to ensure that c does not slip away underneath us
665 read_unlock(&tasklist_lock
);
675 #endif /* CONFIG_MM_OWNER */
678 * Turn us into a lazy TLB process if we
681 static void exit_mm(struct task_struct
* tsk
)
683 struct mm_struct
*mm
= tsk
->mm
;
684 struct core_state
*core_state
;
690 * Serialize with any possible pending coredump.
691 * We must hold mmap_sem around checking core_state
692 * and clearing tsk->mm. The core-inducing thread
693 * will increment ->nr_threads for each thread in the
694 * group with ->mm != NULL.
696 down_read(&mm
->mmap_sem
);
697 core_state
= mm
->core_state
;
699 struct core_thread self
;
700 up_read(&mm
->mmap_sem
);
703 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
705 * Implies mb(), the result of xchg() must be visible
706 * to core_state->dumper.
708 if (atomic_dec_and_test(&core_state
->nr_threads
))
709 complete(&core_state
->startup
);
712 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
713 if (!self
.task
) /* see coredump_finish() */
717 __set_task_state(tsk
, TASK_RUNNING
);
718 down_read(&mm
->mmap_sem
);
720 atomic_inc(&mm
->mm_count
);
721 BUG_ON(mm
!= tsk
->active_mm
);
722 /* more a memory barrier than a real lock */
725 up_read(&mm
->mmap_sem
);
726 enter_lazy_tlb(mm
, current
);
727 /* We don't want this task to be frozen prematurely */
728 clear_freeze_flag(tsk
);
730 mm_update_next_owner(mm
);
735 * Called with irqs disabled, returns true if childs should reap themselves.
737 static int ignoring_children(struct sighand_struct
*sigh
)
740 spin_lock(&sigh
->siglock
);
741 ret
= (sigh
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
) ||
742 (sigh
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
);
743 spin_unlock(&sigh
->siglock
);
747 /* Returns nonzero if the tracee should be released. */
748 int __ptrace_detach(struct task_struct
*tracer
, struct task_struct
*p
)
752 if (p
->exit_state
!= EXIT_ZOMBIE
)
755 * If it's a zombie, our attachedness prevented normal
756 * parent notification or self-reaping. Do notification
757 * now if it would have happened earlier. If it should
758 * reap itself we return true.
760 * If it's our own child, there is no notification to do.
761 * But if our normal children self-reap, then this child
762 * was prevented by ptrace and we must reap it now.
764 if (!task_detached(p
) && thread_group_empty(p
)) {
765 if (!same_thread_group(p
->real_parent
, tracer
))
766 do_notify_parent(p
, p
->exit_signal
);
767 else if (ignoring_children(tracer
->sighand
))
771 if (!task_detached(p
))
774 /* Mark it as in the process of being reaped. */
775 p
->exit_state
= EXIT_DEAD
;
780 * Detach all tasks we were using ptrace on.
781 * Any that need to be release_task'd are put on the @dead list.
783 * Called with write_lock(&tasklist_lock) held.
785 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
787 struct task_struct
*p
, *n
;
789 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
790 if (__ptrace_detach(parent
, p
))
791 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 (task_detached(p
))
823 /* If this is a threaded reparent there is no need to
824 * notify anyone anything has happened.
826 if (same_thread_group(p
->real_parent
, father
))
829 /* We don't want people slaying init. */
830 p
->exit_signal
= SIGCHLD
;
832 /* If we'd notified the old parent about this child's death,
833 * also notify the new parent.
836 p
->exit_state
== EXIT_ZOMBIE
&& 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
;
980 free
= stack_not_used(current
);
982 if (free
>= lowest_to_date
)
985 spin_lock(&low_water_lock
);
986 if (free
< lowest_to_date
) {
987 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
989 current
->comm
, free
);
990 lowest_to_date
= free
;
992 spin_unlock(&low_water_lock
);
995 static inline void check_stack_usage(void) {}
998 NORET_TYPE
void do_exit(long code
)
1000 struct task_struct
*tsk
= current
;
1003 profile_task_exit(tsk
);
1005 WARN_ON(atomic_read(&tsk
->fs_excl
));
1007 if (unlikely(in_interrupt()))
1008 panic("Aiee, killing interrupt handler!");
1009 if (unlikely(!tsk
->pid
))
1010 panic("Attempted to kill the idle task!");
1012 tracehook_report_exit(&code
);
1015 * We're taking recursive faults here in do_exit. Safest is to just
1016 * leave this task alone and wait for reboot.
1018 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1020 "Fixing recursive fault but reboot is needed!\n");
1022 * We can do this unlocked here. The futex code uses
1023 * this flag just to verify whether the pi state
1024 * cleanup has been done or not. In the worst case it
1025 * loops once more. We pretend that the cleanup was
1026 * done as there is no way to return. Either the
1027 * OWNER_DIED bit is set by now or we push the blocked
1028 * task into the wait for ever nirwana as well.
1030 tsk
->flags
|= PF_EXITPIDONE
;
1031 set_current_state(TASK_UNINTERRUPTIBLE
);
1035 exit_signals(tsk
); /* sets PF_EXITING */
1037 * tsk->flags are checked in the futex code to protect against
1038 * an exiting task cleaning up the robust pi futexes.
1041 spin_unlock_wait(&tsk
->pi_lock
);
1043 if (unlikely(in_atomic()))
1044 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1045 current
->comm
, task_pid_nr(current
),
1048 acct_update_integrals(tsk
);
1050 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1052 hrtimer_cancel(&tsk
->signal
->real_timer
);
1053 exit_itimers(tsk
->signal
);
1055 acct_collect(code
, group_dead
);
1058 if (unlikely(tsk
->audit_context
))
1061 tsk
->exit_code
= code
;
1062 taskstats_exit(tsk
, group_dead
);
1068 trace_sched_process_exit(tsk
);
1073 check_stack_usage();
1075 cgroup_exit(tsk
, 1);
1077 if (group_dead
&& tsk
->signal
->leader
)
1078 disassociate_ctty(1);
1080 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1082 module_put(tsk
->binfmt
->module
);
1084 proc_exit_connector(tsk
);
1085 exit_notify(tsk
, group_dead
);
1087 mpol_put(tsk
->mempolicy
);
1088 tsk
->mempolicy
= NULL
;
1092 * This must happen late, after the PID is not
1095 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1096 exit_pi_state_list(tsk
);
1097 if (unlikely(current
->pi_state_cache
))
1098 kfree(current
->pi_state_cache
);
1101 * Make sure we are holding no locks:
1103 debug_check_no_locks_held(tsk
);
1105 * We can do this unlocked here. The futex code uses this flag
1106 * just to verify whether the pi state cleanup has been done
1107 * or not. In the worst case it loops once more.
1109 tsk
->flags
|= PF_EXITPIDONE
;
1111 if (tsk
->io_context
)
1114 if (tsk
->splice_pipe
)
1115 __free_pipe_info(tsk
->splice_pipe
);
1118 /* causes final put_task_struct in finish_task_switch(). */
1119 tsk
->state
= TASK_DEAD
;
1122 /* Avoid "noreturn function does return". */
1124 cpu_relax(); /* For when BUG is null */
1127 EXPORT_SYMBOL_GPL(do_exit
);
1129 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1137 EXPORT_SYMBOL(complete_and_exit
);
1139 SYSCALL_DEFINE1(exit
, int, error_code
)
1141 do_exit((error_code
&0xff)<<8);
1145 * Take down every thread in the group. This is called by fatal signals
1146 * as well as by sys_exit_group (below).
1149 do_group_exit(int exit_code
)
1151 struct signal_struct
*sig
= current
->signal
;
1153 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1155 if (signal_group_exit(sig
))
1156 exit_code
= sig
->group_exit_code
;
1157 else if (!thread_group_empty(current
)) {
1158 struct sighand_struct
*const sighand
= current
->sighand
;
1159 spin_lock_irq(&sighand
->siglock
);
1160 if (signal_group_exit(sig
))
1161 /* Another thread got here before we took the lock. */
1162 exit_code
= sig
->group_exit_code
;
1164 sig
->group_exit_code
= exit_code
;
1165 sig
->flags
= SIGNAL_GROUP_EXIT
;
1166 zap_other_threads(current
);
1168 spin_unlock_irq(&sighand
->siglock
);
1176 * this kills every thread in the thread group. Note that any externally
1177 * wait4()-ing process will get the correct exit code - even if this
1178 * thread is not the thread group leader.
1180 SYSCALL_DEFINE1(exit_group
, int, error_code
)
1182 do_group_exit((error_code
& 0xff) << 8);
1187 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1189 struct pid
*pid
= NULL
;
1190 if (type
== PIDTYPE_PID
)
1191 pid
= task
->pids
[type
].pid
;
1192 else if (type
< PIDTYPE_MAX
)
1193 pid
= task
->group_leader
->pids
[type
].pid
;
1197 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1198 struct task_struct
*p
)
1202 if (type
< PIDTYPE_MAX
) {
1203 if (task_pid_type(p
, type
) != pid
)
1207 /* Wait for all children (clone and not) if __WALL is set;
1208 * otherwise, wait for clone children *only* if __WCLONE is
1209 * set; otherwise, wait for non-clone children *only*. (Note:
1210 * A "clone" child here is one that reports to its parent
1211 * using a signal other than SIGCHLD.) */
1212 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1213 && !(options
& __WALL
))
1216 err
= security_task_wait(p
);
1223 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1224 int why
, int status
,
1225 struct siginfo __user
*infop
,
1226 struct rusage __user
*rusagep
)
1228 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1232 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1234 retval
= put_user(0, &infop
->si_errno
);
1236 retval
= put_user((short)why
, &infop
->si_code
);
1238 retval
= put_user(pid
, &infop
->si_pid
);
1240 retval
= put_user(uid
, &infop
->si_uid
);
1242 retval
= put_user(status
, &infop
->si_status
);
1249 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1250 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1251 * the lock and this task is uninteresting. If we return nonzero, we have
1252 * released the lock and the system call should return.
1254 static int wait_task_zombie(struct task_struct
*p
, int options
,
1255 struct siginfo __user
*infop
,
1256 int __user
*stat_addr
, struct rusage __user
*ru
)
1258 unsigned long state
;
1259 int retval
, status
, traced
;
1260 pid_t pid
= task_pid_vnr(p
);
1261 uid_t uid
= __task_cred(p
)->uid
;
1263 if (!likely(options
& WEXITED
))
1266 if (unlikely(options
& WNOWAIT
)) {
1267 int exit_code
= p
->exit_code
;
1271 read_unlock(&tasklist_lock
);
1272 if ((exit_code
& 0x7f) == 0) {
1274 status
= exit_code
>> 8;
1276 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1277 status
= exit_code
& 0x7f;
1279 return wait_noreap_copyout(p
, pid
, uid
, why
,
1284 * Try to move the task's state to DEAD
1285 * only one thread is allowed to do this:
1287 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1288 if (state
!= EXIT_ZOMBIE
) {
1289 BUG_ON(state
!= EXIT_DEAD
);
1293 traced
= ptrace_reparented(p
);
1295 if (likely(!traced
)) {
1296 struct signal_struct
*psig
;
1297 struct signal_struct
*sig
;
1298 struct task_cputime cputime
;
1301 * The resource counters for the group leader are in its
1302 * own task_struct. Those for dead threads in the group
1303 * are in its signal_struct, as are those for the child
1304 * processes it has previously reaped. All these
1305 * accumulate in the parent's signal_struct c* fields.
1307 * We don't bother to take a lock here to protect these
1308 * p->signal fields, because they are only touched by
1309 * __exit_signal, which runs with tasklist_lock
1310 * write-locked anyway, and so is excluded here. We do
1311 * need to protect the access to p->parent->signal fields,
1312 * as other threads in the parent group can be right
1313 * here reaping other children at the same time.
1315 * We use thread_group_cputime() to get times for the thread
1316 * group, which consolidates times for all threads in the
1317 * group including the group leader.
1319 thread_group_cputime(p
, &cputime
);
1320 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1321 psig
= p
->parent
->signal
;
1324 cputime_add(psig
->cutime
,
1325 cputime_add(cputime
.utime
,
1328 cputime_add(psig
->cstime
,
1329 cputime_add(cputime
.stime
,
1332 cputime_add(psig
->cgtime
,
1333 cputime_add(p
->gtime
,
1334 cputime_add(sig
->gtime
,
1337 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1339 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1341 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1343 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1345 task_io_get_inblock(p
) +
1346 sig
->inblock
+ sig
->cinblock
;
1348 task_io_get_oublock(p
) +
1349 sig
->oublock
+ sig
->coublock
;
1350 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1351 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1352 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1356 * Now we are sure this task is interesting, and no other
1357 * thread can reap it because we set its state to EXIT_DEAD.
1359 read_unlock(&tasklist_lock
);
1361 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1362 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1363 ? p
->signal
->group_exit_code
: p
->exit_code
;
1364 if (!retval
&& stat_addr
)
1365 retval
= put_user(status
, stat_addr
);
1366 if (!retval
&& infop
)
1367 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1368 if (!retval
&& infop
)
1369 retval
= put_user(0, &infop
->si_errno
);
1370 if (!retval
&& infop
) {
1373 if ((status
& 0x7f) == 0) {
1377 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1380 retval
= put_user((short)why
, &infop
->si_code
);
1382 retval
= put_user(status
, &infop
->si_status
);
1384 if (!retval
&& infop
)
1385 retval
= put_user(pid
, &infop
->si_pid
);
1386 if (!retval
&& infop
)
1387 retval
= put_user(uid
, &infop
->si_uid
);
1392 write_lock_irq(&tasklist_lock
);
1393 /* We dropped tasklist, ptracer could die and untrace */
1396 * If this is not a detached task, notify the parent.
1397 * If it's still not detached after that, don't release
1400 if (!task_detached(p
)) {
1401 do_notify_parent(p
, p
->exit_signal
);
1402 if (!task_detached(p
)) {
1403 p
->exit_state
= EXIT_ZOMBIE
;
1407 write_unlock_irq(&tasklist_lock
);
1415 static int *task_stopped_code(struct task_struct
*p
, bool ptrace
)
1418 if (task_is_stopped_or_traced(p
))
1419 return &p
->exit_code
;
1421 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
)
1422 return &p
->signal
->group_exit_code
;
1428 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1429 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1430 * the lock and this task is uninteresting. If we return nonzero, we have
1431 * released the lock and the system call should return.
1433 static int wait_task_stopped(int ptrace
, struct task_struct
*p
,
1434 int options
, struct siginfo __user
*infop
,
1435 int __user
*stat_addr
, struct rusage __user
*ru
)
1437 int retval
, exit_code
, *p_code
, why
;
1438 uid_t uid
= 0; /* unneeded, required by compiler */
1441 if (!(options
& WUNTRACED
))
1445 spin_lock_irq(&p
->sighand
->siglock
);
1447 p_code
= task_stopped_code(p
, ptrace
);
1448 if (unlikely(!p_code
))
1451 exit_code
= *p_code
;
1455 if (!unlikely(options
& WNOWAIT
))
1458 /* don't need the RCU readlock here as we're holding a spinlock */
1459 uid
= __task_cred(p
)->uid
;
1461 spin_unlock_irq(&p
->sighand
->siglock
);
1466 * Now we are pretty sure this task is interesting.
1467 * Make sure it doesn't get reaped out from under us while we
1468 * give up the lock and then examine it below. We don't want to
1469 * keep holding onto the tasklist_lock while we call getrusage and
1470 * possibly take page faults for user memory.
1473 pid
= task_pid_vnr(p
);
1474 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1475 read_unlock(&tasklist_lock
);
1477 if (unlikely(options
& WNOWAIT
))
1478 return wait_noreap_copyout(p
, pid
, uid
,
1482 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1483 if (!retval
&& stat_addr
)
1484 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1485 if (!retval
&& infop
)
1486 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1487 if (!retval
&& infop
)
1488 retval
= put_user(0, &infop
->si_errno
);
1489 if (!retval
&& infop
)
1490 retval
= put_user((short)why
, &infop
->si_code
);
1491 if (!retval
&& infop
)
1492 retval
= put_user(exit_code
, &infop
->si_status
);
1493 if (!retval
&& infop
)
1494 retval
= put_user(pid
, &infop
->si_pid
);
1495 if (!retval
&& infop
)
1496 retval
= put_user(uid
, &infop
->si_uid
);
1506 * Handle do_wait work for one task in a live, non-stopped state.
1507 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1508 * the lock and this task is uninteresting. If we return nonzero, we have
1509 * released the lock and the system call should return.
1511 static int wait_task_continued(struct task_struct
*p
, int options
,
1512 struct siginfo __user
*infop
,
1513 int __user
*stat_addr
, struct rusage __user
*ru
)
1519 if (!unlikely(options
& WCONTINUED
))
1522 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1525 spin_lock_irq(&p
->sighand
->siglock
);
1526 /* Re-check with the lock held. */
1527 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1528 spin_unlock_irq(&p
->sighand
->siglock
);
1531 if (!unlikely(options
& WNOWAIT
))
1532 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1533 uid
= __task_cred(p
)->uid
;
1534 spin_unlock_irq(&p
->sighand
->siglock
);
1536 pid
= task_pid_vnr(p
);
1538 read_unlock(&tasklist_lock
);
1541 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1543 if (!retval
&& stat_addr
)
1544 retval
= put_user(0xffff, stat_addr
);
1548 retval
= wait_noreap_copyout(p
, pid
, uid
,
1549 CLD_CONTINUED
, SIGCONT
,
1551 BUG_ON(retval
== 0);
1558 * Consider @p for a wait by @parent.
1560 * -ECHILD should be in *@notask_error before the first call.
1561 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1562 * Returns zero if the search for a child should continue;
1563 * then *@notask_error is 0 if @p is an eligible child,
1564 * or another error from security_task_wait(), or still -ECHILD.
1566 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1567 struct task_struct
*p
, int *notask_error
,
1568 enum pid_type type
, struct pid
*pid
, int options
,
1569 struct siginfo __user
*infop
,
1570 int __user
*stat_addr
, struct rusage __user
*ru
)
1572 int ret
= eligible_child(type
, pid
, options
, p
);
1576 if (unlikely(ret
< 0)) {
1578 * If we have not yet seen any eligible child,
1579 * then let this error code replace -ECHILD.
1580 * A permission error will give the user a clue
1581 * to look for security policy problems, rather
1582 * than for mysterious wait bugs.
1585 *notask_error
= ret
;
1588 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1590 * This child is hidden by ptrace.
1591 * We aren't allowed to see it now, but eventually we will.
1597 if (p
->exit_state
== EXIT_DEAD
)
1601 * We don't reap group leaders with subthreads.
1603 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1604 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1607 * It's stopped or running now, so it might
1608 * later continue, exit, or stop again.
1612 if (task_stopped_code(p
, ptrace
))
1613 return wait_task_stopped(ptrace
, p
, options
,
1614 infop
, stat_addr
, ru
);
1616 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1620 * Do the work of do_wait() for one thread in the group, @tsk.
1622 * -ECHILD should be in *@notask_error before the first call.
1623 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1624 * Returns zero if the search for a child should continue; then
1625 * *@notask_error is 0 if there were any eligible children,
1626 * or another error from security_task_wait(), or still -ECHILD.
1628 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1629 enum pid_type type
, struct pid
*pid
, int options
,
1630 struct siginfo __user
*infop
, int __user
*stat_addr
,
1631 struct rusage __user
*ru
)
1633 struct task_struct
*p
;
1635 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1637 * Do not consider detached threads.
1639 if (!task_detached(p
)) {
1640 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1642 infop
, stat_addr
, ru
);
1651 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1652 enum pid_type type
, struct pid
*pid
, int options
,
1653 struct siginfo __user
*infop
, int __user
*stat_addr
,
1654 struct rusage __user
*ru
)
1656 struct task_struct
*p
;
1659 * Traditionally we see ptrace'd stopped tasks regardless of options.
1661 options
|= WUNTRACED
;
1663 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1664 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1666 infop
, stat_addr
, ru
);
1674 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1675 struct siginfo __user
*infop
, int __user
*stat_addr
,
1676 struct rusage __user
*ru
)
1678 DECLARE_WAITQUEUE(wait
, current
);
1679 struct task_struct
*tsk
;
1682 trace_sched_process_wait(pid
);
1684 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1687 * If there is nothing that can match our critiera just get out.
1688 * We will clear @retval to zero if we see any child that might later
1689 * match our criteria, even if we are not able to reap it yet.
1692 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1695 current
->state
= TASK_INTERRUPTIBLE
;
1696 read_lock(&tasklist_lock
);
1699 int tsk_result
= do_wait_thread(tsk
, &retval
,
1701 infop
, stat_addr
, ru
);
1703 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1705 infop
, stat_addr
, ru
);
1708 * tasklist_lock is unlocked and we have a final result.
1710 retval
= tsk_result
;
1714 if (options
& __WNOTHREAD
)
1716 tsk
= next_thread(tsk
);
1717 BUG_ON(tsk
->signal
!= current
->signal
);
1718 } while (tsk
!= current
);
1719 read_unlock(&tasklist_lock
);
1721 if (!retval
&& !(options
& WNOHANG
)) {
1722 retval
= -ERESTARTSYS
;
1723 if (!signal_pending(current
)) {
1730 current
->state
= TASK_RUNNING
;
1731 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1737 * For a WNOHANG return, clear out all the fields
1738 * we would set so the user can easily tell the
1742 retval
= put_user(0, &infop
->si_signo
);
1744 retval
= put_user(0, &infop
->si_errno
);
1746 retval
= put_user(0, &infop
->si_code
);
1748 retval
= put_user(0, &infop
->si_pid
);
1750 retval
= put_user(0, &infop
->si_uid
);
1752 retval
= put_user(0, &infop
->si_status
);
1758 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1759 infop
, int, options
, struct rusage __user
*, ru
)
1761 struct pid
*pid
= NULL
;
1765 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1767 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1780 type
= PIDTYPE_PGID
;
1788 if (type
< PIDTYPE_MAX
)
1789 pid
= find_get_pid(upid
);
1790 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1793 /* avoid REGPARM breakage on x86: */
1794 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1798 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1799 int, options
, struct rusage __user
*, ru
)
1801 struct pid
*pid
= NULL
;
1805 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1806 __WNOTHREAD
|__WCLONE
|__WALL
))
1811 else if (upid
< 0) {
1812 type
= PIDTYPE_PGID
;
1813 pid
= find_get_pid(-upid
);
1814 } else if (upid
== 0) {
1815 type
= PIDTYPE_PGID
;
1816 pid
= get_pid(task_pgrp(current
));
1817 } else /* upid > 0 */ {
1819 pid
= find_get_pid(upid
);
1822 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1825 /* avoid REGPARM breakage on x86: */
1826 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1830 #ifdef __ARCH_WANT_SYS_WAITPID
1833 * sys_waitpid() remains for compatibility. waitpid() should be
1834 * implemented by calling sys_wait4() from libc.a.
1836 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1838 return sys_wait4(pid
, stat_addr
, options
, NULL
);