]>
git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - kernel/exit.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/capability.h>
12 #include <linux/completion.h>
13 #include <linux/personality.h>
14 #include <linux/tty.h>
15 #include <linux/mnt_namespace.h>
16 #include <linux/iocontext.h>
17 #include <linux/key.h>
18 #include <linux/security.h>
19 #include <linux/cpu.h>
20 #include <linux/acct.h>
21 #include <linux/tsacct_kern.h>
22 #include <linux/file.h>
23 #include <linux/fdtable.h>
24 #include <linux/binfmts.h>
25 #include <linux/nsproxy.h>
26 #include <linux/pid_namespace.h>
27 #include <linux/ptrace.h>
28 #include <linux/profile.h>
29 #include <linux/mount.h>
30 #include <linux/proc_fs.h>
31 #include <linux/kthread.h>
32 #include <linux/mempolicy.h>
33 #include <linux/taskstats_kern.h>
34 #include <linux/delayacct.h>
35 #include <linux/freezer.h>
36 #include <linux/cgroup.h>
37 #include <linux/syscalls.h>
38 #include <linux/signal.h>
39 #include <linux/posix-timers.h>
40 #include <linux/cn_proc.h>
41 #include <linux/mutex.h>
42 #include <linux/futex.h>
43 #include <linux/compat.h>
44 #include <linux/pipe_fs_i.h>
45 #include <linux/audit.h> /* for audit_free() */
46 #include <linux/resource.h>
47 #include <linux/blkdev.h>
48 #include <linux/task_io_accounting_ops.h>
49 #include <linux/tracehook.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>
57 static void exit_mm(struct task_struct
* tsk
);
59 static inline int task_detached(struct task_struct
*p
)
61 return p
->exit_signal
== -1;
64 static void __unhash_process(struct task_struct
*p
)
67 detach_pid(p
, PIDTYPE_PID
);
68 if (thread_group_leader(p
)) {
69 detach_pid(p
, PIDTYPE_PGID
);
70 detach_pid(p
, PIDTYPE_SID
);
72 list_del_rcu(&p
->tasks
);
73 __get_cpu_var(process_counts
)--;
75 list_del_rcu(&p
->thread_group
);
76 list_del_init(&p
->sibling
);
80 * This function expects the tasklist_lock write-locked.
82 static void __exit_signal(struct task_struct
*tsk
)
84 struct signal_struct
*sig
= tsk
->signal
;
85 struct sighand_struct
*sighand
;
88 BUG_ON(!atomic_read(&sig
->count
));
90 sighand
= rcu_dereference(tsk
->sighand
);
91 spin_lock(&sighand
->siglock
);
93 posix_cpu_timers_exit(tsk
);
94 if (atomic_dec_and_test(&sig
->count
))
95 posix_cpu_timers_exit_group(tsk
);
98 * If there is any task waiting for the group exit
101 if (sig
->group_exit_task
&& atomic_read(&sig
->count
) == sig
->notify_count
)
102 wake_up_process(sig
->group_exit_task
);
104 if (tsk
== sig
->curr_target
)
105 sig
->curr_target
= next_thread(tsk
);
107 * Accumulate here the counters for all threads but the
108 * group leader as they die, so they can be added into
109 * the process-wide totals when those are taken.
110 * The group leader stays around as a zombie as long
111 * as there are other threads. When it gets reaped,
112 * the exit.c code will add its counts into these totals.
113 * We won't ever get here for the group leader, since it
114 * will have been the last reference on the signal_struct.
116 sig
->gtime
= cputime_add(sig
->gtime
, task_gtime(tsk
));
117 sig
->min_flt
+= tsk
->min_flt
;
118 sig
->maj_flt
+= tsk
->maj_flt
;
119 sig
->nvcsw
+= tsk
->nvcsw
;
120 sig
->nivcsw
+= tsk
->nivcsw
;
121 sig
->inblock
+= task_io_get_inblock(tsk
);
122 sig
->oublock
+= task_io_get_oublock(tsk
);
123 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
124 sig
= NULL
; /* Marker for below. */
127 __unhash_process(tsk
);
130 * Do this under ->siglock, we can race with another thread
131 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
133 flush_sigqueue(&tsk
->pending
);
137 spin_unlock(&sighand
->siglock
);
139 __cleanup_sighand(sighand
);
140 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
142 flush_sigqueue(&sig
->shared_pending
);
143 taskstats_tgid_free(sig
);
144 __cleanup_signal(sig
);
148 static void delayed_put_task_struct(struct rcu_head
*rhp
)
150 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
152 trace_sched_process_free(tsk
);
153 put_task_struct(tsk
);
157 void release_task(struct task_struct
* p
)
159 struct task_struct
*leader
;
162 tracehook_prepare_release_task(p
);
163 /* don't need to get the RCU readlock here - the process is dead and
164 * can't be modifying its own credentials */
165 atomic_dec(&__task_cred(p
)->user
->processes
);
168 write_lock_irq(&tasklist_lock
);
169 tracehook_finish_release_task(p
);
173 * If we are the last non-leader member of the thread
174 * group, and the leader is zombie, then notify the
175 * group leader's parent process. (if it wants notification.)
178 leader
= p
->group_leader
;
179 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
180 BUG_ON(task_detached(leader
));
181 do_notify_parent(leader
, leader
->exit_signal
);
183 * If we were the last child thread and the leader has
184 * exited already, and the leader's parent ignores SIGCHLD,
185 * then we are the one who should release the leader.
187 * do_notify_parent() will have marked it self-reaping in
190 zap_leader
= task_detached(leader
);
193 * This maintains the invariant that release_task()
194 * only runs on a task in EXIT_DEAD, just for sanity.
197 leader
->exit_state
= EXIT_DEAD
;
200 write_unlock_irq(&tasklist_lock
);
202 call_rcu(&p
->rcu
, delayed_put_task_struct
);
205 if (unlikely(zap_leader
))
210 * This checks not only the pgrp, but falls back on the pid if no
211 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
214 * The caller must hold rcu lock or the tasklist lock.
216 struct pid
*session_of_pgrp(struct pid
*pgrp
)
218 struct task_struct
*p
;
219 struct pid
*sid
= NULL
;
221 p
= pid_task(pgrp
, PIDTYPE_PGID
);
223 p
= pid_task(pgrp
, PIDTYPE_PID
);
225 sid
= task_session(p
);
231 * Determine if a process group is "orphaned", according to the POSIX
232 * definition in 2.2.2.52. Orphaned process groups are not to be affected
233 * by terminal-generated stop signals. Newly orphaned process groups are
234 * to receive a SIGHUP and a SIGCONT.
236 * "I ask you, have you ever known what it is to be an orphan?"
238 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
240 struct task_struct
*p
;
242 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
243 if ((p
== ignored_task
) ||
244 (p
->exit_state
&& thread_group_empty(p
)) ||
245 is_global_init(p
->real_parent
))
248 if (task_pgrp(p
->real_parent
) != pgrp
&&
249 task_session(p
->real_parent
) == task_session(p
))
251 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
256 int is_current_pgrp_orphaned(void)
260 read_lock(&tasklist_lock
);
261 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
262 read_unlock(&tasklist_lock
);
267 static int has_stopped_jobs(struct pid
*pgrp
)
270 struct task_struct
*p
;
272 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
273 if (!task_is_stopped(p
))
277 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
282 * Check to see if any process groups have become orphaned as
283 * a result of our exiting, and if they have any stopped jobs,
284 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
287 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
289 struct pid
*pgrp
= task_pgrp(tsk
);
290 struct task_struct
*ignored_task
= tsk
;
293 /* exit: our father is in a different pgrp than
294 * we are and we were the only connection outside.
296 parent
= tsk
->real_parent
;
298 /* reparent: our child is in a different pgrp than
299 * we are, and it was the only connection outside.
303 if (task_pgrp(parent
) != pgrp
&&
304 task_session(parent
) == task_session(tsk
) &&
305 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
306 has_stopped_jobs(pgrp
)) {
307 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
308 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
313 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
315 * If a kernel thread is launched as a result of a system call, or if
316 * it ever exits, it should generally reparent itself to kthreadd so it
317 * isn't in the way of other processes and is correctly cleaned up on exit.
319 * The various task state such as scheduling policy and priority may have
320 * been inherited from a user process, so we reset them to sane values here.
322 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
324 static void reparent_to_kthreadd(void)
326 write_lock_irq(&tasklist_lock
);
328 ptrace_unlink(current
);
329 /* Reparent to init */
330 current
->real_parent
= current
->parent
= kthreadd_task
;
331 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
333 /* Set the exit signal to SIGCHLD so we signal init on exit */
334 current
->exit_signal
= SIGCHLD
;
336 if (task_nice(current
) < 0)
337 set_user_nice(current
, 0);
341 security_task_reparent_to_init(current
);
342 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
343 sizeof(current
->signal
->rlim
));
344 atomic_inc(&(INIT_USER
->__count
));
345 write_unlock_irq(&tasklist_lock
);
346 switch_uid(INIT_USER
);
349 void __set_special_pids(struct pid
*pid
)
351 struct task_struct
*curr
= current
->group_leader
;
352 pid_t nr
= pid_nr(pid
);
354 if (task_session(curr
) != pid
) {
355 change_pid(curr
, PIDTYPE_SID
, pid
);
356 set_task_session(curr
, nr
);
358 if (task_pgrp(curr
) != pid
) {
359 change_pid(curr
, PIDTYPE_PGID
, pid
);
360 set_task_pgrp(curr
, nr
);
364 static void set_special_pids(struct pid
*pid
)
366 write_lock_irq(&tasklist_lock
);
367 __set_special_pids(pid
);
368 write_unlock_irq(&tasklist_lock
);
372 * Let kernel threads use this to say that they
373 * allow a certain signal (since daemonize() will
374 * have disabled all of them by default).
376 int allow_signal(int sig
)
378 if (!valid_signal(sig
) || sig
< 1)
381 spin_lock_irq(¤t
->sighand
->siglock
);
382 sigdelset(¤t
->blocked
, sig
);
384 /* Kernel threads handle their own signals.
385 Let the signal code know it'll be handled, so
386 that they don't get converted to SIGKILL or
387 just silently dropped */
388 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
391 spin_unlock_irq(¤t
->sighand
->siglock
);
395 EXPORT_SYMBOL(allow_signal
);
397 int disallow_signal(int sig
)
399 if (!valid_signal(sig
) || sig
< 1)
402 spin_lock_irq(¤t
->sighand
->siglock
);
403 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
405 spin_unlock_irq(¤t
->sighand
->siglock
);
409 EXPORT_SYMBOL(disallow_signal
);
412 * Put all the gunge required to become a kernel thread without
413 * attached user resources in one place where it belongs.
416 void daemonize(const char *name
, ...)
419 struct fs_struct
*fs
;
422 va_start(args
, name
);
423 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
427 * If we were started as result of loading a module, close all of the
428 * user space pages. We don't need them, and if we didn't close them
429 * they would be locked into memory.
433 * We don't want to have TIF_FREEZE set if the system-wide hibernation
434 * or suspend transition begins right now.
436 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
438 if (current
->nsproxy
!= &init_nsproxy
) {
439 get_nsproxy(&init_nsproxy
);
440 switch_task_namespaces(current
, &init_nsproxy
);
442 set_special_pids(&init_struct_pid
);
443 proc_clear_tty(current
);
445 /* Block and flush all signals */
446 sigfillset(&blocked
);
447 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
448 flush_signals(current
);
450 /* Become as one with the init task */
452 exit_fs(current
); /* current->fs->count--; */
455 atomic_inc(&fs
->count
);
458 current
->files
= init_task
.files
;
459 atomic_inc(¤t
->files
->count
);
461 reparent_to_kthreadd();
464 EXPORT_SYMBOL(daemonize
);
466 static void close_files(struct files_struct
* files
)
474 * It is safe to dereference the fd table without RCU or
475 * ->file_lock because this is the last reference to the
478 fdt
= files_fdtable(files
);
482 if (i
>= fdt
->max_fds
)
484 set
= fdt
->open_fds
->fds_bits
[j
++];
487 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
489 filp_close(file
, files
);
499 struct files_struct
*get_files_struct(struct task_struct
*task
)
501 struct files_struct
*files
;
506 atomic_inc(&files
->count
);
512 void put_files_struct(struct files_struct
*files
)
516 if (atomic_dec_and_test(&files
->count
)) {
519 * Free the fd and fdset arrays if we expanded them.
520 * If the fdtable was embedded, pass files for freeing
521 * at the end of the RCU grace period. Otherwise,
522 * you can free files immediately.
524 fdt
= files_fdtable(files
);
525 if (fdt
!= &files
->fdtab
)
526 kmem_cache_free(files_cachep
, files
);
531 void reset_files_struct(struct files_struct
*files
)
533 struct task_struct
*tsk
= current
;
534 struct files_struct
*old
;
540 put_files_struct(old
);
543 void exit_files(struct task_struct
*tsk
)
545 struct files_struct
* files
= tsk
->files
;
551 put_files_struct(files
);
555 void put_fs_struct(struct fs_struct
*fs
)
557 /* No need to hold fs->lock if we are killing it */
558 if (atomic_dec_and_test(&fs
->count
)) {
561 kmem_cache_free(fs_cachep
, fs
);
565 void exit_fs(struct task_struct
*tsk
)
567 struct fs_struct
* fs
= tsk
->fs
;
577 EXPORT_SYMBOL_GPL(exit_fs
);
579 #ifdef CONFIG_MM_OWNER
581 * Task p is exiting and it owned mm, lets find a new owner for it
584 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
587 * If there are other users of the mm and the owner (us) is exiting
588 * we need to find a new owner to take on the responsibility.
590 if (atomic_read(&mm
->mm_users
) <= 1)
597 void mm_update_next_owner(struct mm_struct
*mm
)
599 struct task_struct
*c
, *g
, *p
= current
;
602 if (!mm_need_new_owner(mm
, p
))
605 read_lock(&tasklist_lock
);
607 * Search in the children
609 list_for_each_entry(c
, &p
->children
, sibling
) {
611 goto assign_new_owner
;
615 * Search in the siblings
617 list_for_each_entry(c
, &p
->parent
->children
, sibling
) {
619 goto assign_new_owner
;
623 * Search through everything else. We should not get
626 do_each_thread(g
, c
) {
628 goto assign_new_owner
;
629 } while_each_thread(g
, c
);
631 read_unlock(&tasklist_lock
);
633 * We found no owner yet mm_users > 1: this implies that we are
634 * most likely racing with swapoff (try_to_unuse()) or /proc or
635 * ptrace or page migration (get_task_mm()). Mark owner as NULL,
636 * so that subsystems can understand the callback and take action.
638 down_write(&mm
->mmap_sem
);
639 cgroup_mm_owner_callbacks(mm
->owner
, NULL
);
641 up_write(&mm
->mmap_sem
);
647 read_unlock(&tasklist_lock
);
648 down_write(&mm
->mmap_sem
);
650 * The task_lock protects c->mm from changing.
651 * We always want mm->owner->mm == mm
656 up_write(&mm
->mmap_sem
);
660 cgroup_mm_owner_callbacks(mm
->owner
, c
);
663 up_write(&mm
->mmap_sem
);
666 #endif /* CONFIG_MM_OWNER */
669 * Turn us into a lazy TLB process if we
672 static void exit_mm(struct task_struct
* tsk
)
674 struct mm_struct
*mm
= tsk
->mm
;
675 struct core_state
*core_state
;
681 * Serialize with any possible pending coredump.
682 * We must hold mmap_sem around checking core_state
683 * and clearing tsk->mm. The core-inducing thread
684 * will increment ->nr_threads for each thread in the
685 * group with ->mm != NULL.
687 down_read(&mm
->mmap_sem
);
688 core_state
= mm
->core_state
;
690 struct core_thread self
;
691 up_read(&mm
->mmap_sem
);
694 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
696 * Implies mb(), the result of xchg() must be visible
697 * to core_state->dumper.
699 if (atomic_dec_and_test(&core_state
->nr_threads
))
700 complete(&core_state
->startup
);
703 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
704 if (!self
.task
) /* see coredump_finish() */
708 __set_task_state(tsk
, TASK_RUNNING
);
709 down_read(&mm
->mmap_sem
);
711 atomic_inc(&mm
->mm_count
);
712 BUG_ON(mm
!= tsk
->active_mm
);
713 /* more a memory barrier than a real lock */
716 up_read(&mm
->mmap_sem
);
717 enter_lazy_tlb(mm
, current
);
718 /* We don't want this task to be frozen prematurely */
719 clear_freeze_flag(tsk
);
721 mm_update_next_owner(mm
);
726 * Return nonzero if @parent's children should reap themselves.
728 * Called with write_lock_irq(&tasklist_lock) held.
730 static int ignoring_children(struct task_struct
*parent
)
733 struct sighand_struct
*psig
= parent
->sighand
;
735 spin_lock_irqsave(&psig
->siglock
, flags
);
736 ret
= (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
737 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
));
738 spin_unlock_irqrestore(&psig
->siglock
, flags
);
743 * Detach all tasks we were using ptrace on.
744 * Any that need to be release_task'd are put on the @dead list.
746 * Called with write_lock(&tasklist_lock) held.
748 static void ptrace_exit(struct task_struct
*parent
, struct list_head
*dead
)
750 struct task_struct
*p
, *n
;
753 list_for_each_entry_safe(p
, n
, &parent
->ptraced
, ptrace_entry
) {
756 if (p
->exit_state
!= EXIT_ZOMBIE
)
760 * If it's a zombie, our attachedness prevented normal
761 * parent notification or self-reaping. Do notification
762 * now if it would have happened earlier. If it should
763 * reap itself, add it to the @dead list. We can't call
764 * release_task() here because we already hold tasklist_lock.
766 * If it's our own child, there is no notification to do.
767 * But if our normal children self-reap, then this child
768 * was prevented by ptrace and we must reap it now.
770 if (!task_detached(p
) && thread_group_empty(p
)) {
771 if (!same_thread_group(p
->real_parent
, parent
))
772 do_notify_parent(p
, p
->exit_signal
);
775 ign
= ignoring_children(parent
);
781 if (task_detached(p
)) {
783 * Mark it as in the process of being reaped.
785 p
->exit_state
= EXIT_DEAD
;
786 list_add(&p
->ptrace_entry
, dead
);
792 * Finish up exit-time ptrace cleanup.
794 * Called without locks.
796 static void ptrace_exit_finish(struct task_struct
*parent
,
797 struct list_head
*dead
)
799 struct task_struct
*p
, *n
;
801 BUG_ON(!list_empty(&parent
->ptraced
));
803 list_for_each_entry_safe(p
, n
, dead
, ptrace_entry
) {
804 list_del_init(&p
->ptrace_entry
);
809 static void reparent_thread(struct task_struct
*p
, struct task_struct
*father
)
811 if (p
->pdeath_signal
)
812 /* We already hold the tasklist_lock here. */
813 group_send_sig_info(p
->pdeath_signal
, SEND_SIG_NOINFO
, p
);
815 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
817 /* If this is a threaded reparent there is no need to
818 * notify anyone anything has happened.
820 if (same_thread_group(p
->real_parent
, father
))
823 /* We don't want people slaying init. */
824 if (!task_detached(p
))
825 p
->exit_signal
= SIGCHLD
;
827 /* If we'd notified the old parent about this child's death,
828 * also notify the new parent.
830 if (!ptrace_reparented(p
) &&
831 p
->exit_state
== EXIT_ZOMBIE
&&
832 !task_detached(p
) && thread_group_empty(p
))
833 do_notify_parent(p
, p
->exit_signal
);
835 kill_orphaned_pgrp(p
, father
);
839 * When we die, we re-parent all our children.
840 * Try to give them to another thread in our thread
841 * group, and if no such member exists, give it to
842 * the child reaper process (ie "init") in our pid
845 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
847 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
848 struct task_struct
*thread
;
851 while_each_thread(father
, thread
) {
852 if (thread
->flags
& PF_EXITING
)
854 if (unlikely(pid_ns
->child_reaper
== father
))
855 pid_ns
->child_reaper
= thread
;
859 if (unlikely(pid_ns
->child_reaper
== father
)) {
860 write_unlock_irq(&tasklist_lock
);
861 if (unlikely(pid_ns
== &init_pid_ns
))
862 panic("Attempted to kill init!");
864 zap_pid_ns_processes(pid_ns
);
865 write_lock_irq(&tasklist_lock
);
867 * We can not clear ->child_reaper or leave it alone.
868 * There may by stealth EXIT_DEAD tasks on ->children,
869 * forget_original_parent() must move them somewhere.
871 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
874 return pid_ns
->child_reaper
;
877 static void forget_original_parent(struct task_struct
*father
)
879 struct task_struct
*p
, *n
, *reaper
;
880 LIST_HEAD(ptrace_dead
);
882 write_lock_irq(&tasklist_lock
);
883 reaper
= find_new_reaper(father
);
885 * First clean up ptrace if we were using it.
887 ptrace_exit(father
, &ptrace_dead
);
889 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
890 p
->real_parent
= reaper
;
891 if (p
->parent
== father
) {
893 p
->parent
= p
->real_parent
;
895 reparent_thread(p
, father
);
898 write_unlock_irq(&tasklist_lock
);
899 BUG_ON(!list_empty(&father
->children
));
901 ptrace_exit_finish(father
, &ptrace_dead
);
905 * Send signals to all our closest relatives so that they know
906 * to properly mourn us..
908 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
914 * This does two things:
916 * A. Make init inherit all the child processes
917 * B. Check to see if any process groups have become orphaned
918 * as a result of our exiting, and if they have any stopped
919 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
921 forget_original_parent(tsk
);
922 exit_task_namespaces(tsk
);
924 write_lock_irq(&tasklist_lock
);
926 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
928 /* Let father know we died
930 * Thread signals are configurable, but you aren't going to use
931 * that to send signals to arbitary processes.
932 * That stops right now.
934 * If the parent exec id doesn't match the exec id we saved
935 * when we started then we know the parent has changed security
938 * If our self_exec id doesn't match our parent_exec_id then
939 * we have changed execution domain as these two values started
940 * the same after a fork.
942 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
943 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
944 tsk
->self_exec_id
!= tsk
->parent_exec_id
) &&
946 tsk
->exit_signal
= SIGCHLD
;
948 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
950 signal
= do_notify_parent(tsk
, signal
);
952 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
954 /* mt-exec, de_thread() is waiting for us */
955 if (thread_group_leader(tsk
) &&
956 tsk
->signal
->group_exit_task
&&
957 tsk
->signal
->notify_count
< 0)
958 wake_up_process(tsk
->signal
->group_exit_task
);
960 write_unlock_irq(&tasklist_lock
);
962 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
964 /* If the process is dead, release it - nobody will wait for it */
965 if (signal
== DEATH_REAP
)
969 #ifdef CONFIG_DEBUG_STACK_USAGE
970 static void check_stack_usage(void)
972 static DEFINE_SPINLOCK(low_water_lock
);
973 static int lowest_to_date
= THREAD_SIZE
;
974 unsigned long *n
= end_of_stack(current
);
979 free
= (unsigned long)n
- (unsigned long)end_of_stack(current
);
981 if (free
>= lowest_to_date
)
984 spin_lock(&low_water_lock
);
985 if (free
< lowest_to_date
) {
986 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
988 current
->comm
, free
);
989 lowest_to_date
= free
;
991 spin_unlock(&low_water_lock
);
994 static inline void check_stack_usage(void) {}
997 NORET_TYPE
void do_exit(long code
)
999 struct task_struct
*tsk
= current
;
1002 profile_task_exit(tsk
);
1004 WARN_ON(atomic_read(&tsk
->fs_excl
));
1006 if (unlikely(in_interrupt()))
1007 panic("Aiee, killing interrupt handler!");
1008 if (unlikely(!tsk
->pid
))
1009 panic("Attempted to kill the idle task!");
1011 tracehook_report_exit(&code
);
1014 * We're taking recursive faults here in do_exit. Safest is to just
1015 * leave this task alone and wait for reboot.
1017 if (unlikely(tsk
->flags
& PF_EXITING
)) {
1019 "Fixing recursive fault but reboot is needed!\n");
1021 * We can do this unlocked here. The futex code uses
1022 * this flag just to verify whether the pi state
1023 * cleanup has been done or not. In the worst case it
1024 * loops once more. We pretend that the cleanup was
1025 * done as there is no way to return. Either the
1026 * OWNER_DIED bit is set by now or we push the blocked
1027 * task into the wait for ever nirwana as well.
1029 tsk
->flags
|= PF_EXITPIDONE
;
1030 if (tsk
->io_context
)
1032 set_current_state(TASK_UNINTERRUPTIBLE
);
1036 exit_signals(tsk
); /* sets PF_EXITING */
1038 * tsk->flags are checked in the futex code to protect against
1039 * an exiting task cleaning up the robust pi futexes.
1042 spin_unlock_wait(&tsk
->pi_lock
);
1044 if (unlikely(in_atomic()))
1045 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
1046 current
->comm
, task_pid_nr(current
),
1049 acct_update_integrals(tsk
);
1051 update_hiwater_rss(tsk
->mm
);
1052 update_hiwater_vm(tsk
->mm
);
1054 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
1056 hrtimer_cancel(&tsk
->signal
->real_timer
);
1057 exit_itimers(tsk
->signal
);
1059 acct_collect(code
, group_dead
);
1061 if (unlikely(tsk
->robust_list
))
1062 exit_robust_list(tsk
);
1063 #ifdef CONFIG_COMPAT
1064 if (unlikely(tsk
->compat_robust_list
))
1065 compat_exit_robust_list(tsk
);
1070 if (unlikely(tsk
->audit_context
))
1073 tsk
->exit_code
= code
;
1074 taskstats_exit(tsk
, group_dead
);
1080 trace_sched_process_exit(tsk
);
1085 check_stack_usage();
1087 cgroup_exit(tsk
, 1);
1090 if (group_dead
&& tsk
->signal
->leader
)
1091 disassociate_ctty(1);
1093 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1095 module_put(tsk
->binfmt
->module
);
1097 proc_exit_connector(tsk
);
1098 exit_notify(tsk
, group_dead
);
1100 mpol_put(tsk
->mempolicy
);
1101 tsk
->mempolicy
= NULL
;
1105 * This must happen late, after the PID is not
1108 if (unlikely(!list_empty(&tsk
->pi_state_list
)))
1109 exit_pi_state_list(tsk
);
1110 if (unlikely(current
->pi_state_cache
))
1111 kfree(current
->pi_state_cache
);
1114 * Make sure we are holding no locks:
1116 debug_check_no_locks_held(tsk
);
1118 * We can do this unlocked here. The futex code uses this flag
1119 * just to verify whether the pi state cleanup has been done
1120 * or not. In the worst case it loops once more.
1122 tsk
->flags
|= PF_EXITPIDONE
;
1124 if (tsk
->io_context
)
1127 if (tsk
->splice_pipe
)
1128 __free_pipe_info(tsk
->splice_pipe
);
1131 /* causes final put_task_struct in finish_task_switch(). */
1132 tsk
->state
= TASK_DEAD
;
1136 /* Avoid "noreturn function does return". */
1138 cpu_relax(); /* For when BUG is null */
1141 EXPORT_SYMBOL_GPL(do_exit
);
1143 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1151 EXPORT_SYMBOL(complete_and_exit
);
1153 asmlinkage
long sys_exit(int error_code
)
1155 do_exit((error_code
&0xff)<<8);
1159 * Take down every thread in the group. This is called by fatal signals
1160 * as well as by sys_exit_group (below).
1163 do_group_exit(int exit_code
)
1165 struct signal_struct
*sig
= current
->signal
;
1167 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1169 if (signal_group_exit(sig
))
1170 exit_code
= sig
->group_exit_code
;
1171 else if (!thread_group_empty(current
)) {
1172 struct sighand_struct
*const sighand
= current
->sighand
;
1173 spin_lock_irq(&sighand
->siglock
);
1174 if (signal_group_exit(sig
))
1175 /* Another thread got here before we took the lock. */
1176 exit_code
= sig
->group_exit_code
;
1178 sig
->group_exit_code
= exit_code
;
1179 sig
->flags
= SIGNAL_GROUP_EXIT
;
1180 zap_other_threads(current
);
1182 spin_unlock_irq(&sighand
->siglock
);
1190 * this kills every thread in the thread group. Note that any externally
1191 * wait4()-ing process will get the correct exit code - even if this
1192 * thread is not the thread group leader.
1194 asmlinkage
void sys_exit_group(int error_code
)
1196 do_group_exit((error_code
& 0xff) << 8);
1199 static struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1201 struct pid
*pid
= NULL
;
1202 if (type
== PIDTYPE_PID
)
1203 pid
= task
->pids
[type
].pid
;
1204 else if (type
< PIDTYPE_MAX
)
1205 pid
= task
->group_leader
->pids
[type
].pid
;
1209 static int eligible_child(enum pid_type type
, struct pid
*pid
, int options
,
1210 struct task_struct
*p
)
1214 if (type
< PIDTYPE_MAX
) {
1215 if (task_pid_type(p
, type
) != pid
)
1219 /* Wait for all children (clone and not) if __WALL is set;
1220 * otherwise, wait for clone children *only* if __WCLONE is
1221 * set; otherwise, wait for non-clone children *only*. (Note:
1222 * A "clone" child here is one that reports to its parent
1223 * using a signal other than SIGCHLD.) */
1224 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
1225 && !(options
& __WALL
))
1228 err
= security_task_wait(p
);
1235 static int wait_noreap_copyout(struct task_struct
*p
, pid_t pid
, uid_t uid
,
1236 int why
, int status
,
1237 struct siginfo __user
*infop
,
1238 struct rusage __user
*rusagep
)
1240 int retval
= rusagep
? getrusage(p
, RUSAGE_BOTH
, rusagep
) : 0;
1244 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1246 retval
= put_user(0, &infop
->si_errno
);
1248 retval
= put_user((short)why
, &infop
->si_code
);
1250 retval
= put_user(pid
, &infop
->si_pid
);
1252 retval
= put_user(uid
, &infop
->si_uid
);
1254 retval
= put_user(status
, &infop
->si_status
);
1261 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1262 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1263 * the lock and this task is uninteresting. If we return nonzero, we have
1264 * released the lock and the system call should return.
1266 static int wait_task_zombie(struct task_struct
*p
, int options
,
1267 struct siginfo __user
*infop
,
1268 int __user
*stat_addr
, struct rusage __user
*ru
)
1270 unsigned long state
;
1271 int retval
, status
, traced
;
1272 pid_t pid
= task_pid_vnr(p
);
1273 uid_t uid
= __task_cred(p
)->uid
;
1275 if (!likely(options
& WEXITED
))
1278 if (unlikely(options
& WNOWAIT
)) {
1279 int exit_code
= p
->exit_code
;
1283 read_unlock(&tasklist_lock
);
1284 if ((exit_code
& 0x7f) == 0) {
1286 status
= exit_code
>> 8;
1288 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1289 status
= exit_code
& 0x7f;
1291 return wait_noreap_copyout(p
, pid
, uid
, why
,
1296 * Try to move the task's state to DEAD
1297 * only one thread is allowed to do this:
1299 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1300 if (state
!= EXIT_ZOMBIE
) {
1301 BUG_ON(state
!= EXIT_DEAD
);
1305 traced
= ptrace_reparented(p
);
1307 if (likely(!traced
)) {
1308 struct signal_struct
*psig
;
1309 struct signal_struct
*sig
;
1310 struct task_cputime cputime
;
1313 * The resource counters for the group leader are in its
1314 * own task_struct. Those for dead threads in the group
1315 * are in its signal_struct, as are those for the child
1316 * processes it has previously reaped. All these
1317 * accumulate in the parent's signal_struct c* fields.
1319 * We don't bother to take a lock here to protect these
1320 * p->signal fields, because they are only touched by
1321 * __exit_signal, which runs with tasklist_lock
1322 * write-locked anyway, and so is excluded here. We do
1323 * need to protect the access to p->parent->signal fields,
1324 * as other threads in the parent group can be right
1325 * here reaping other children at the same time.
1327 * We use thread_group_cputime() to get times for the thread
1328 * group, which consolidates times for all threads in the
1329 * group including the group leader.
1331 spin_lock_irq(&p
->parent
->sighand
->siglock
);
1332 psig
= p
->parent
->signal
;
1334 thread_group_cputime(p
, &cputime
);
1336 cputime_add(psig
->cutime
,
1337 cputime_add(cputime
.utime
,
1340 cputime_add(psig
->cstime
,
1341 cputime_add(cputime
.stime
,
1344 cputime_add(psig
->cgtime
,
1345 cputime_add(p
->gtime
,
1346 cputime_add(sig
->gtime
,
1349 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1351 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1353 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1355 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1357 task_io_get_inblock(p
) +
1358 sig
->inblock
+ sig
->cinblock
;
1360 task_io_get_oublock(p
) +
1361 sig
->oublock
+ sig
->coublock
;
1362 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1363 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1364 spin_unlock_irq(&p
->parent
->sighand
->siglock
);
1368 * Now we are sure this task is interesting, and no other
1369 * thread can reap it because we set its state to EXIT_DEAD.
1371 read_unlock(&tasklist_lock
);
1373 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1374 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1375 ? p
->signal
->group_exit_code
: p
->exit_code
;
1376 if (!retval
&& stat_addr
)
1377 retval
= put_user(status
, stat_addr
);
1378 if (!retval
&& infop
)
1379 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1380 if (!retval
&& infop
)
1381 retval
= put_user(0, &infop
->si_errno
);
1382 if (!retval
&& infop
) {
1385 if ((status
& 0x7f) == 0) {
1389 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1392 retval
= put_user((short)why
, &infop
->si_code
);
1394 retval
= put_user(status
, &infop
->si_status
);
1396 if (!retval
&& infop
)
1397 retval
= put_user(pid
, &infop
->si_pid
);
1398 if (!retval
&& infop
)
1399 retval
= put_user(uid
, &infop
->si_uid
);
1404 write_lock_irq(&tasklist_lock
);
1405 /* We dropped tasklist, ptracer could die and untrace */
1408 * If this is not a detached task, notify the parent.
1409 * If it's still not detached after that, don't release
1412 if (!task_detached(p
)) {
1413 do_notify_parent(p
, p
->exit_signal
);
1414 if (!task_detached(p
)) {
1415 p
->exit_state
= EXIT_ZOMBIE
;
1419 write_unlock_irq(&tasklist_lock
);
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
, why
;
1438 uid_t uid
= 0; /* unneeded, required by compiler */
1441 if (!(options
& WUNTRACED
))
1445 spin_lock_irq(&p
->sighand
->siglock
);
1447 if (unlikely(!task_is_stopped_or_traced(p
)))
1450 if (!ptrace
&& p
->signal
->group_stop_count
> 0)
1452 * A group stop is in progress and this is the group leader.
1453 * We won't report until all threads have stopped.
1457 exit_code
= p
->exit_code
;
1461 if (!unlikely(options
& WNOWAIT
))
1464 /* don't need the RCU readlock here as we're holding a spinlock */
1465 uid
= __task_cred(p
)->uid
;
1467 spin_unlock_irq(&p
->sighand
->siglock
);
1472 * Now we are pretty sure this task is interesting.
1473 * Make sure it doesn't get reaped out from under us while we
1474 * give up the lock and then examine it below. We don't want to
1475 * keep holding onto the tasklist_lock while we call getrusage and
1476 * possibly take page faults for user memory.
1479 pid
= task_pid_vnr(p
);
1480 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1481 read_unlock(&tasklist_lock
);
1483 if (unlikely(options
& WNOWAIT
))
1484 return wait_noreap_copyout(p
, pid
, uid
,
1488 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1489 if (!retval
&& stat_addr
)
1490 retval
= put_user((exit_code
<< 8) | 0x7f, stat_addr
);
1491 if (!retval
&& infop
)
1492 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1493 if (!retval
&& infop
)
1494 retval
= put_user(0, &infop
->si_errno
);
1495 if (!retval
&& infop
)
1496 retval
= put_user((short)why
, &infop
->si_code
);
1497 if (!retval
&& infop
)
1498 retval
= put_user(exit_code
, &infop
->si_status
);
1499 if (!retval
&& infop
)
1500 retval
= put_user(pid
, &infop
->si_pid
);
1501 if (!retval
&& infop
)
1502 retval
= put_user(uid
, &infop
->si_uid
);
1512 * Handle do_wait work for one task in a live, non-stopped state.
1513 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1514 * the lock and this task is uninteresting. If we return nonzero, we have
1515 * released the lock and the system call should return.
1517 static int wait_task_continued(struct task_struct
*p
, int options
,
1518 struct siginfo __user
*infop
,
1519 int __user
*stat_addr
, struct rusage __user
*ru
)
1525 if (!unlikely(options
& WCONTINUED
))
1528 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1531 spin_lock_irq(&p
->sighand
->siglock
);
1532 /* Re-check with the lock held. */
1533 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1534 spin_unlock_irq(&p
->sighand
->siglock
);
1537 if (!unlikely(options
& WNOWAIT
))
1538 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1539 uid
= __task_cred(p
)->uid
;
1540 spin_unlock_irq(&p
->sighand
->siglock
);
1542 pid
= task_pid_vnr(p
);
1544 read_unlock(&tasklist_lock
);
1547 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
1549 if (!retval
&& stat_addr
)
1550 retval
= put_user(0xffff, stat_addr
);
1554 retval
= wait_noreap_copyout(p
, pid
, uid
,
1555 CLD_CONTINUED
, SIGCONT
,
1557 BUG_ON(retval
== 0);
1564 * Consider @p for a wait by @parent.
1566 * -ECHILD should be in *@notask_error before the first call.
1567 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1568 * Returns zero if the search for a child should continue;
1569 * then *@notask_error is 0 if @p is an eligible child,
1570 * or another error from security_task_wait(), or still -ECHILD.
1572 static int wait_consider_task(struct task_struct
*parent
, int ptrace
,
1573 struct task_struct
*p
, int *notask_error
,
1574 enum pid_type type
, struct pid
*pid
, int options
,
1575 struct siginfo __user
*infop
,
1576 int __user
*stat_addr
, struct rusage __user
*ru
)
1578 int ret
= eligible_child(type
, pid
, options
, p
);
1582 if (unlikely(ret
< 0)) {
1584 * If we have not yet seen any eligible child,
1585 * then let this error code replace -ECHILD.
1586 * A permission error will give the user a clue
1587 * to look for security policy problems, rather
1588 * than for mysterious wait bugs.
1591 *notask_error
= ret
;
1594 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1596 * This child is hidden by ptrace.
1597 * We aren't allowed to see it now, but eventually we will.
1603 if (p
->exit_state
== EXIT_DEAD
)
1607 * We don't reap group leaders with subthreads.
1609 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1610 return wait_task_zombie(p
, options
, infop
, stat_addr
, ru
);
1613 * It's stopped or running now, so it might
1614 * later continue, exit, or stop again.
1618 if (task_is_stopped_or_traced(p
))
1619 return wait_task_stopped(ptrace
, p
, options
,
1620 infop
, stat_addr
, ru
);
1622 return wait_task_continued(p
, options
, infop
, stat_addr
, ru
);
1626 * Do the work of do_wait() for one thread in the group, @tsk.
1628 * -ECHILD should be in *@notask_error before the first call.
1629 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1630 * Returns zero if the search for a child should continue; then
1631 * *@notask_error is 0 if there were any eligible children,
1632 * or another error from security_task_wait(), or still -ECHILD.
1634 static int do_wait_thread(struct task_struct
*tsk
, int *notask_error
,
1635 enum pid_type type
, struct pid
*pid
, int options
,
1636 struct siginfo __user
*infop
, int __user
*stat_addr
,
1637 struct rusage __user
*ru
)
1639 struct task_struct
*p
;
1641 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1643 * Do not consider detached threads.
1645 if (!task_detached(p
)) {
1646 int ret
= wait_consider_task(tsk
, 0, p
, notask_error
,
1648 infop
, stat_addr
, ru
);
1657 static int ptrace_do_wait(struct task_struct
*tsk
, int *notask_error
,
1658 enum pid_type type
, struct pid
*pid
, int options
,
1659 struct siginfo __user
*infop
, int __user
*stat_addr
,
1660 struct rusage __user
*ru
)
1662 struct task_struct
*p
;
1665 * Traditionally we see ptrace'd stopped tasks regardless of options.
1667 options
|= WUNTRACED
;
1669 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1670 int ret
= wait_consider_task(tsk
, 1, p
, notask_error
,
1672 infop
, stat_addr
, ru
);
1680 static long do_wait(enum pid_type type
, struct pid
*pid
, int options
,
1681 struct siginfo __user
*infop
, int __user
*stat_addr
,
1682 struct rusage __user
*ru
)
1684 DECLARE_WAITQUEUE(wait
, current
);
1685 struct task_struct
*tsk
;
1688 trace_sched_process_wait(pid
);
1690 add_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1693 * If there is nothing that can match our critiera just get out.
1694 * We will clear @retval to zero if we see any child that might later
1695 * match our criteria, even if we are not able to reap it yet.
1698 if ((type
< PIDTYPE_MAX
) && (!pid
|| hlist_empty(&pid
->tasks
[type
])))
1701 current
->state
= TASK_INTERRUPTIBLE
;
1702 read_lock(&tasklist_lock
);
1705 int tsk_result
= do_wait_thread(tsk
, &retval
,
1707 infop
, stat_addr
, ru
);
1709 tsk_result
= ptrace_do_wait(tsk
, &retval
,
1711 infop
, stat_addr
, ru
);
1714 * tasklist_lock is unlocked and we have a final result.
1716 retval
= tsk_result
;
1720 if (options
& __WNOTHREAD
)
1722 tsk
= next_thread(tsk
);
1723 BUG_ON(tsk
->signal
!= current
->signal
);
1724 } while (tsk
!= current
);
1725 read_unlock(&tasklist_lock
);
1727 if (!retval
&& !(options
& WNOHANG
)) {
1728 retval
= -ERESTARTSYS
;
1729 if (!signal_pending(current
)) {
1736 current
->state
= TASK_RUNNING
;
1737 remove_wait_queue(¤t
->signal
->wait_chldexit
,&wait
);
1743 * For a WNOHANG return, clear out all the fields
1744 * we would set so the user can easily tell the
1748 retval
= put_user(0, &infop
->si_signo
);
1750 retval
= put_user(0, &infop
->si_errno
);
1752 retval
= put_user(0, &infop
->si_code
);
1754 retval
= put_user(0, &infop
->si_pid
);
1756 retval
= put_user(0, &infop
->si_uid
);
1758 retval
= put_user(0, &infop
->si_status
);
1764 asmlinkage
long sys_waitid(int which
, pid_t upid
,
1765 struct siginfo __user
*infop
, int options
,
1766 struct rusage __user
*ru
)
1768 struct pid
*pid
= NULL
;
1772 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1774 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1787 type
= PIDTYPE_PGID
;
1795 if (type
< PIDTYPE_MAX
)
1796 pid
= find_get_pid(upid
);
1797 ret
= do_wait(type
, pid
, options
, infop
, NULL
, ru
);
1800 /* avoid REGPARM breakage on x86: */
1801 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1805 asmlinkage
long sys_wait4(pid_t upid
, int __user
*stat_addr
,
1806 int options
, struct rusage __user
*ru
)
1808 struct pid
*pid
= NULL
;
1812 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1813 __WNOTHREAD
|__WCLONE
|__WALL
))
1818 else if (upid
< 0) {
1819 type
= PIDTYPE_PGID
;
1820 pid
= find_get_pid(-upid
);
1821 } else if (upid
== 0) {
1822 type
= PIDTYPE_PGID
;
1823 pid
= get_pid(task_pgrp(current
));
1824 } else /* upid > 0 */ {
1826 pid
= find_get_pid(upid
);
1829 ret
= do_wait(type
, pid
, options
| WEXITED
, NULL
, stat_addr
, ru
);
1832 /* avoid REGPARM breakage on x86: */
1833 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1837 #ifdef __ARCH_WANT_SYS_WAITPID
1840 * sys_waitpid() remains for compatibility. waitpid() should be
1841 * implemented by calling sys_wait4() from libc.a.
1843 asmlinkage
long sys_waitpid(pid_t pid
, int __user
*stat_addr
, int options
)
1845 return sys_wait4(pid
, stat_addr
, options
, NULL
);