]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - kernel/exit.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/capability.h>
12 #include <linux/completion.h>
13 #include <linux/personality.h>
14 #include <linux/tty.h>
15 #include <linux/iocontext.h>
16 #include <linux/key.h>
17 #include <linux/security.h>
18 #include <linux/cpu.h>
19 #include <linux/acct.h>
20 #include <linux/tsacct_kern.h>
21 #include <linux/file.h>
22 #include <linux/fdtable.h>
23 #include <linux/binfmts.h>
24 #include <linux/nsproxy.h>
25 #include <linux/pid_namespace.h>
26 #include <linux/ptrace.h>
27 #include <linux/profile.h>
28 #include <linux/mount.h>
29 #include <linux/proc_fs.h>
30 #include <linux/kthread.h>
31 #include <linux/mempolicy.h>
32 #include <linux/taskstats_kern.h>
33 #include <linux/delayacct.h>
34 #include <linux/freezer.h>
35 #include <linux/cgroup.h>
36 #include <linux/syscalls.h>
37 #include <linux/signal.h>
38 #include <linux/posix-timers.h>
39 #include <linux/cn_proc.h>
40 #include <linux/mutex.h>
41 #include <linux/futex.h>
42 #include <linux/pipe_fs_i.h>
43 #include <linux/audit.h> /* for audit_free() */
44 #include <linux/resource.h>
45 #include <linux/blkdev.h>
46 #include <linux/task_io_accounting_ops.h>
47 #include <linux/tracehook.h>
48 #include <linux/fs_struct.h>
49 #include <linux/init_task.h>
50 #include <linux/perf_event.h>
51 #include <trace/events/sched.h>
52 #include <linux/hw_breakpoint.h>
53 #include <linux/oom.h>
55 #include <asm/uaccess.h>
56 #include <asm/unistd.h>
57 #include <asm/pgtable.h>
58 #include <asm/mmu_context.h>
60 static void exit_mm(struct task_struct
* tsk
);
62 static void __unhash_process(struct task_struct
*p
, bool group_dead
)
65 detach_pid(p
, PIDTYPE_PID
);
67 detach_pid(p
, PIDTYPE_PGID
);
68 detach_pid(p
, PIDTYPE_SID
);
70 list_del_rcu(&p
->tasks
);
71 list_del_init(&p
->sibling
);
72 __this_cpu_dec(process_counts
);
74 list_del_rcu(&p
->thread_group
);
78 * This function expects the tasklist_lock write-locked.
80 static void __exit_signal(struct task_struct
*tsk
)
82 struct signal_struct
*sig
= tsk
->signal
;
83 bool group_dead
= thread_group_leader(tsk
);
84 struct sighand_struct
*sighand
;
85 struct tty_struct
*uninitialized_var(tty
);
87 sighand
= rcu_dereference_check(tsk
->sighand
,
88 rcu_read_lock_held() ||
89 lockdep_tasklist_lock_is_held());
90 spin_lock(&sighand
->siglock
);
92 posix_cpu_timers_exit(tsk
);
94 posix_cpu_timers_exit_group(tsk
);
99 * This can only happen if the caller is de_thread().
100 * FIXME: this is the temporary hack, we should teach
101 * posix-cpu-timers to handle this case correctly.
103 if (unlikely(has_group_leader_pid(tsk
)))
104 posix_cpu_timers_exit_group(tsk
);
107 * If there is any task waiting for the group exit
110 if (sig
->notify_count
> 0 && !--sig
->notify_count
)
111 wake_up_process(sig
->group_exit_task
);
113 if (tsk
== sig
->curr_target
)
114 sig
->curr_target
= next_thread(tsk
);
116 * Accumulate here the counters for all threads but the
117 * group leader as they die, so they can be added into
118 * the process-wide totals when those are taken.
119 * The group leader stays around as a zombie as long
120 * as there are other threads. When it gets reaped,
121 * the exit.c code will add its counts into these totals.
122 * We won't ever get here for the group leader, since it
123 * will have been the last reference on the signal_struct.
125 sig
->utime
= cputime_add(sig
->utime
, tsk
->utime
);
126 sig
->stime
= cputime_add(sig
->stime
, tsk
->stime
);
127 sig
->gtime
= cputime_add(sig
->gtime
, tsk
->gtime
);
128 sig
->min_flt
+= tsk
->min_flt
;
129 sig
->maj_flt
+= tsk
->maj_flt
;
130 sig
->nvcsw
+= tsk
->nvcsw
;
131 sig
->nivcsw
+= tsk
->nivcsw
;
132 sig
->inblock
+= task_io_get_inblock(tsk
);
133 sig
->oublock
+= task_io_get_oublock(tsk
);
134 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
135 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
139 __unhash_process(tsk
, group_dead
);
142 * Do this under ->siglock, we can race with another thread
143 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
145 flush_sigqueue(&tsk
->pending
);
147 spin_unlock(&sighand
->siglock
);
149 __cleanup_sighand(sighand
);
150 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
152 flush_sigqueue(&sig
->shared_pending
);
157 static void delayed_put_task_struct(struct rcu_head
*rhp
)
159 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
161 perf_event_delayed_put(tsk
);
162 trace_sched_process_free(tsk
);
163 put_task_struct(tsk
);
167 void release_task(struct task_struct
* p
)
169 struct task_struct
*leader
;
172 /* don't need to get the RCU readlock here - the process is dead and
173 * can't be modifying its own credentials. But shut RCU-lockdep up */
175 atomic_dec(&__task_cred(p
)->user
->processes
);
180 write_lock_irq(&tasklist_lock
);
181 ptrace_release_task(p
);
185 * If we are the last non-leader member of the thread
186 * group, and the leader is zombie, then notify the
187 * group leader's parent process. (if it wants notification.)
190 leader
= p
->group_leader
;
191 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
192 BUG_ON(task_detached(leader
));
193 do_notify_parent(leader
, leader
->exit_signal
);
195 * If we were the last child thread and the leader has
196 * exited already, and the leader's parent ignores SIGCHLD,
197 * then we are the one who should release the leader.
199 * do_notify_parent() will have marked it self-reaping in
202 zap_leader
= task_detached(leader
);
205 * This maintains the invariant that release_task()
206 * only runs on a task in EXIT_DEAD, just for sanity.
209 leader
->exit_state
= EXIT_DEAD
;
212 write_unlock_irq(&tasklist_lock
);
214 call_rcu(&p
->rcu
, delayed_put_task_struct
);
217 if (unlikely(zap_leader
))
222 * This checks not only the pgrp, but falls back on the pid if no
223 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
226 * The caller must hold rcu lock or the tasklist lock.
228 struct pid
*session_of_pgrp(struct pid
*pgrp
)
230 struct task_struct
*p
;
231 struct pid
*sid
= NULL
;
233 p
= pid_task(pgrp
, PIDTYPE_PGID
);
235 p
= pid_task(pgrp
, PIDTYPE_PID
);
237 sid
= task_session(p
);
243 * Determine if a process group is "orphaned", according to the POSIX
244 * definition in 2.2.2.52. Orphaned process groups are not to be affected
245 * by terminal-generated stop signals. Newly orphaned process groups are
246 * to receive a SIGHUP and a SIGCONT.
248 * "I ask you, have you ever known what it is to be an orphan?"
250 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
252 struct task_struct
*p
;
254 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
255 if ((p
== ignored_task
) ||
256 (p
->exit_state
&& thread_group_empty(p
)) ||
257 is_global_init(p
->real_parent
))
260 if (task_pgrp(p
->real_parent
) != pgrp
&&
261 task_session(p
->real_parent
) == task_session(p
))
263 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
268 int is_current_pgrp_orphaned(void)
272 read_lock(&tasklist_lock
);
273 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
274 read_unlock(&tasklist_lock
);
279 static int has_stopped_jobs(struct pid
*pgrp
)
282 struct task_struct
*p
;
284 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
285 if (!task_is_stopped(p
))
289 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
294 * Check to see if any process groups have become orphaned as
295 * a result of our exiting, and if they have any stopped jobs,
296 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
299 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
301 struct pid
*pgrp
= task_pgrp(tsk
);
302 struct task_struct
*ignored_task
= tsk
;
305 /* exit: our father is in a different pgrp than
306 * we are and we were the only connection outside.
308 parent
= tsk
->real_parent
;
310 /* reparent: our child is in a different pgrp than
311 * we are, and it was the only connection outside.
315 if (task_pgrp(parent
) != pgrp
&&
316 task_session(parent
) == task_session(tsk
) &&
317 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
318 has_stopped_jobs(pgrp
)) {
319 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
320 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
325 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
327 * If a kernel thread is launched as a result of a system call, or if
328 * it ever exits, it should generally reparent itself to kthreadd so it
329 * isn't in the way of other processes and is correctly cleaned up on exit.
331 * The various task state such as scheduling policy and priority may have
332 * been inherited from a user process, so we reset them to sane values here.
334 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
336 static void reparent_to_kthreadd(void)
338 write_lock_irq(&tasklist_lock
);
340 ptrace_unlink(current
);
341 /* Reparent to init */
342 current
->real_parent
= current
->parent
= kthreadd_task
;
343 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
345 /* Set the exit signal to SIGCHLD so we signal init on exit */
346 current
->exit_signal
= SIGCHLD
;
348 if (task_nice(current
) < 0)
349 set_user_nice(current
, 0);
353 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
354 sizeof(current
->signal
->rlim
));
356 atomic_inc(&init_cred
.usage
);
357 commit_creds(&init_cred
);
358 write_unlock_irq(&tasklist_lock
);
361 void __set_special_pids(struct pid
*pid
)
363 struct task_struct
*curr
= current
->group_leader
;
365 if (task_session(curr
) != pid
)
366 change_pid(curr
, PIDTYPE_SID
, pid
);
368 if (task_pgrp(curr
) != pid
)
369 change_pid(curr
, PIDTYPE_PGID
, pid
);
372 static void set_special_pids(struct pid
*pid
)
374 write_lock_irq(&tasklist_lock
);
375 __set_special_pids(pid
);
376 write_unlock_irq(&tasklist_lock
);
380 * Let kernel threads use this to say that they allow a certain signal.
381 * Must not be used if kthread was cloned with CLONE_SIGHAND.
383 int allow_signal(int sig
)
385 if (!valid_signal(sig
) || sig
< 1)
388 spin_lock_irq(¤t
->sighand
->siglock
);
389 /* This is only needed for daemonize()'ed kthreads */
390 sigdelset(¤t
->blocked
, sig
);
392 * Kernel threads handle their own signals. Let the signal code
393 * know it'll be handled, so that they don't get converted to
394 * SIGKILL or just silently dropped.
396 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
398 spin_unlock_irq(¤t
->sighand
->siglock
);
402 EXPORT_SYMBOL(allow_signal
);
404 int disallow_signal(int sig
)
406 if (!valid_signal(sig
) || sig
< 1)
409 spin_lock_irq(¤t
->sighand
->siglock
);
410 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
412 spin_unlock_irq(¤t
->sighand
->siglock
);
416 EXPORT_SYMBOL(disallow_signal
);
419 * Put all the gunge required to become a kernel thread without
420 * attached user resources in one place where it belongs.
423 void daemonize(const char *name
, ...)
428 va_start(args
, name
);
429 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
433 * If we were started as result of loading a module, close all of the
434 * user space pages. We don't need them, and if we didn't close them
435 * they would be locked into memory.
439 * We don't want to have TIF_FREEZE set if the system-wide hibernation
440 * or suspend transition begins right now.
442 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
444 if (current
->nsproxy
!= &init_nsproxy
) {
445 get_nsproxy(&init_nsproxy
);
446 switch_task_namespaces(current
, &init_nsproxy
);
448 set_special_pids(&init_struct_pid
);
449 proc_clear_tty(current
);
451 /* Block and flush all signals */
452 sigfillset(&blocked
);
453 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
454 flush_signals(current
);
456 /* Become as one with the init task */
458 daemonize_fs_struct();
460 current
->files
= init_task
.files
;
461 atomic_inc(¤t
->files
->count
);
463 reparent_to_kthreadd();
466 EXPORT_SYMBOL(daemonize
);
468 static void close_files(struct files_struct
* files
)
476 * It is safe to dereference the fd table without RCU or
477 * ->file_lock because this is the last reference to the
478 * files structure. But use RCU to shut RCU-lockdep up.
481 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.
529 fdt
= files_fdtable(files
);
530 if (fdt
!= &files
->fdtab
)
531 kmem_cache_free(files_cachep
, files
);
537 void reset_files_struct(struct files_struct
*files
)
539 struct task_struct
*tsk
= current
;
540 struct files_struct
*old
;
546 put_files_struct(old
);
549 void exit_files(struct task_struct
*tsk
)
551 struct files_struct
* files
= tsk
->files
;
557 put_files_struct(files
);
561 #ifdef CONFIG_MM_OWNER
563 * Task p is exiting and it owned mm, lets find a new owner for it
566 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
569 * If there are other users of the mm and the owner (us) is exiting
570 * we need to find a new owner to take on the responsibility.
572 if (atomic_read(&mm
->mm_users
) <= 1)
579 void mm_update_next_owner(struct mm_struct
*mm
)
581 struct task_struct
*c
, *g
, *p
= current
;
584 if (!mm_need_new_owner(mm
, p
))
587 read_lock(&tasklist_lock
);
589 * Search in the children
591 list_for_each_entry(c
, &p
->children
, sibling
) {
593 goto assign_new_owner
;
597 * Search in the siblings
599 list_for_each_entry(c
, &p
->real_parent
->children
, sibling
) {
601 goto assign_new_owner
;
605 * Search through everything else. We should not get
608 do_each_thread(g
, c
) {
610 goto assign_new_owner
;
611 } while_each_thread(g
, c
);
613 read_unlock(&tasklist_lock
);
615 * We found no owner yet mm_users > 1: this implies that we are
616 * most likely racing with swapoff (try_to_unuse()) or /proc or
617 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
626 * The task_lock protects c->mm from changing.
627 * We always want mm->owner->mm == mm
631 * Delay read_unlock() till we have the task_lock()
632 * to ensure that c does not slip away underneath us
634 read_unlock(&tasklist_lock
);
644 #endif /* CONFIG_MM_OWNER */
647 * Turn us into a lazy TLB process if we
650 static void exit_mm(struct task_struct
* tsk
)
652 struct mm_struct
*mm
= tsk
->mm
;
653 struct core_state
*core_state
;
659 * Serialize with any possible pending coredump.
660 * We must hold mmap_sem around checking core_state
661 * and clearing tsk->mm. The core-inducing thread
662 * will increment ->nr_threads for each thread in the
663 * group with ->mm != NULL.
665 down_read(&mm
->mmap_sem
);
666 core_state
= mm
->core_state
;
668 struct core_thread self
;
669 up_read(&mm
->mmap_sem
);
672 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
674 * Implies mb(), the result of xchg() must be visible
675 * to core_state->dumper.
677 if (atomic_dec_and_test(&core_state
->nr_threads
))
678 complete(&core_state
->startup
);
681 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
682 if (!self
.task
) /* see coredump_finish() */
686 __set_task_state(tsk
, TASK_RUNNING
);
687 down_read(&mm
->mmap_sem
);
689 atomic_inc(&mm
->mm_count
);
690 BUG_ON(mm
!= tsk
->active_mm
);
691 /* more a memory barrier than a real lock */
694 up_read(&mm
->mmap_sem
);
695 enter_lazy_tlb(mm
, current
);
696 /* We don't want this task to be frozen prematurely */
697 clear_freeze_flag(tsk
);
698 if (tsk
->signal
->oom_score_adj
== OOM_SCORE_ADJ_MIN
)
699 atomic_dec(&mm
->oom_disable_count
);
701 mm_update_next_owner(mm
);
706 * When we die, we re-parent all our children.
707 * Try to give them to another thread in our thread
708 * group, and if no such member exists, give it to
709 * the child reaper process (ie "init") in our pid
712 static struct task_struct
*find_new_reaper(struct task_struct
*father
)
713 __releases(&tasklist_lock
)
714 __acquires(&tasklist_lock
)
716 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
717 struct task_struct
*thread
;
720 while_each_thread(father
, thread
) {
721 if (thread
->flags
& PF_EXITING
)
723 if (unlikely(pid_ns
->child_reaper
== father
))
724 pid_ns
->child_reaper
= thread
;
728 if (unlikely(pid_ns
->child_reaper
== father
)) {
729 write_unlock_irq(&tasklist_lock
);
730 if (unlikely(pid_ns
== &init_pid_ns
))
731 panic("Attempted to kill init!");
733 zap_pid_ns_processes(pid_ns
);
734 write_lock_irq(&tasklist_lock
);
736 * We can not clear ->child_reaper or leave it alone.
737 * There may by stealth EXIT_DEAD tasks on ->children,
738 * forget_original_parent() must move them somewhere.
740 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
743 return pid_ns
->child_reaper
;
747 * Any that need to be release_task'd are put on the @dead list.
749 static void reparent_leader(struct task_struct
*father
, struct task_struct
*p
,
750 struct list_head
*dead
)
752 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
754 if (task_detached(p
))
757 * If this is a threaded reparent there is no need to
758 * notify anyone anything has happened.
760 if (same_thread_group(p
->real_parent
, father
))
763 /* We don't want people slaying init. */
764 p
->exit_signal
= SIGCHLD
;
766 /* If it has exited notify the new parent about this child's death. */
768 p
->exit_state
== EXIT_ZOMBIE
&& thread_group_empty(p
)) {
769 do_notify_parent(p
, p
->exit_signal
);
770 if (task_detached(p
)) {
771 p
->exit_state
= EXIT_DEAD
;
772 list_move_tail(&p
->sibling
, dead
);
776 kill_orphaned_pgrp(p
, father
);
779 static void forget_original_parent(struct task_struct
*father
)
781 struct task_struct
*p
, *n
, *reaper
;
782 LIST_HEAD(dead_children
);
784 write_lock_irq(&tasklist_lock
);
786 * Note that exit_ptrace() and find_new_reaper() might
787 * drop tasklist_lock and reacquire it.
790 reaper
= find_new_reaper(father
);
792 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
793 struct task_struct
*t
= p
;
795 t
->real_parent
= reaper
;
796 if (t
->parent
== father
) {
798 t
->parent
= t
->real_parent
;
800 if (t
->pdeath_signal
)
801 group_send_sig_info(t
->pdeath_signal
,
803 } while_each_thread(p
, t
);
804 reparent_leader(father
, p
, &dead_children
);
806 write_unlock_irq(&tasklist_lock
);
808 BUG_ON(!list_empty(&father
->children
));
810 list_for_each_entry_safe(p
, n
, &dead_children
, sibling
) {
811 list_del_init(&p
->sibling
);
817 * Send signals to all our closest relatives so that they know
818 * to properly mourn us..
820 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
826 * This does two things:
828 * A. Make init inherit all the child processes
829 * B. Check to see if any process groups have become orphaned
830 * as a result of our exiting, and if they have any stopped
831 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
833 forget_original_parent(tsk
);
834 exit_task_namespaces(tsk
);
836 write_lock_irq(&tasklist_lock
);
838 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
840 /* Let father know we died
842 * Thread signals are configurable, but you aren't going to use
843 * that to send signals to arbitrary processes.
844 * That stops right now.
846 * If the parent exec id doesn't match the exec id we saved
847 * when we started then we know the parent has changed security
850 * If our self_exec id doesn't match our parent_exec_id then
851 * we have changed execution domain as these two values started
852 * the same after a fork.
854 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
855 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
856 tsk
->self_exec_id
!= tsk
->parent_exec_id
))
857 tsk
->exit_signal
= SIGCHLD
;
859 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
861 signal
= do_notify_parent(tsk
, signal
);
863 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
865 /* mt-exec, de_thread() is waiting for group leader */
866 if (unlikely(tsk
->signal
->notify_count
< 0))
867 wake_up_process(tsk
->signal
->group_exit_task
);
868 write_unlock_irq(&tasklist_lock
);
870 /* If the process is dead, release it - nobody will wait for it */
871 if (signal
== DEATH_REAP
)
875 #ifdef CONFIG_DEBUG_STACK_USAGE
876 static void check_stack_usage(void)
878 static DEFINE_SPINLOCK(low_water_lock
);
879 static int lowest_to_date
= THREAD_SIZE
;
882 free
= stack_not_used(current
);
884 if (free
>= lowest_to_date
)
887 spin_lock(&low_water_lock
);
888 if (free
< lowest_to_date
) {
889 printk(KERN_WARNING
"%s used greatest stack depth: %lu bytes "
891 current
->comm
, free
);
892 lowest_to_date
= free
;
894 spin_unlock(&low_water_lock
);
897 static inline void check_stack_usage(void) {}
900 NORET_TYPE
void do_exit(long code
)
902 struct task_struct
*tsk
= current
;
905 profile_task_exit(tsk
);
907 WARN_ON(atomic_read(&tsk
->fs_excl
));
908 WARN_ON(blk_needs_flush_plug(tsk
));
910 if (unlikely(in_interrupt()))
911 panic("Aiee, killing interrupt handler!");
912 if (unlikely(!tsk
->pid
))
913 panic("Attempted to kill the idle task!");
916 * If do_exit is called because this processes oopsed, it's possible
917 * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before
918 * continuing. Amongst other possible reasons, this is to prevent
919 * mm_release()->clear_child_tid() from writing to a user-controlled
924 ptrace_event(PTRACE_EVENT_EXIT
, code
);
926 validate_creds_for_do_exit(tsk
);
929 * We're taking recursive faults here in do_exit. Safest is to just
930 * leave this task alone and wait for reboot.
932 if (unlikely(tsk
->flags
& PF_EXITING
)) {
934 "Fixing recursive fault but reboot is needed!\n");
936 * We can do this unlocked here. The futex code uses
937 * this flag just to verify whether the pi state
938 * cleanup has been done or not. In the worst case it
939 * loops once more. We pretend that the cleanup was
940 * done as there is no way to return. Either the
941 * OWNER_DIED bit is set by now or we push the blocked
942 * task into the wait for ever nirwana as well.
944 tsk
->flags
|= PF_EXITPIDONE
;
945 set_current_state(TASK_UNINTERRUPTIBLE
);
951 exit_signals(tsk
); /* sets PF_EXITING */
953 * tsk->flags are checked in the futex code to protect against
954 * an exiting task cleaning up the robust pi futexes.
957 raw_spin_unlock_wait(&tsk
->pi_lock
);
959 if (unlikely(in_atomic()))
960 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
961 current
->comm
, task_pid_nr(current
),
964 acct_update_integrals(tsk
);
965 /* sync mm's RSS info before statistics gathering */
967 sync_mm_rss(tsk
, tsk
->mm
);
968 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
970 hrtimer_cancel(&tsk
->signal
->real_timer
);
971 exit_itimers(tsk
->signal
);
973 setmax_mm_hiwater_rss(&tsk
->signal
->maxrss
, tsk
->mm
);
975 acct_collect(code
, group_dead
);
978 if (unlikely(tsk
->audit_context
))
981 tsk
->exit_code
= code
;
982 taskstats_exit(tsk
, group_dead
);
988 trace_sched_process_exit(tsk
);
997 * Flush inherited counters to the parent - before the parent
998 * gets woken up by child-exit notifications.
1000 * because of cgroup mode, must be called before cgroup_exit()
1002 perf_event_exit_task(tsk
);
1004 cgroup_exit(tsk
, 1);
1007 disassociate_ctty(1);
1009 module_put(task_thread_info(tsk
)->exec_domain
->module
);
1011 proc_exit_connector(tsk
);
1014 * FIXME: do that only when needed, using sched_exit tracepoint
1016 ptrace_put_breakpoints(tsk
);
1018 exit_notify(tsk
, group_dead
);
1021 mpol_put(tsk
->mempolicy
);
1022 tsk
->mempolicy
= NULL
;
1026 if (unlikely(current
->pi_state_cache
))
1027 kfree(current
->pi_state_cache
);
1030 * Make sure we are holding no locks:
1032 debug_check_no_locks_held(tsk
);
1034 * We can do this unlocked here. The futex code uses this flag
1035 * just to verify whether the pi state cleanup has been done
1036 * or not. In the worst case it loops once more.
1038 tsk
->flags
|= PF_EXITPIDONE
;
1040 if (tsk
->io_context
)
1041 exit_io_context(tsk
);
1043 if (tsk
->splice_pipe
)
1044 __free_pipe_info(tsk
->splice_pipe
);
1046 validate_creds_for_do_exit(tsk
);
1050 /* causes final put_task_struct in finish_task_switch(). */
1051 tsk
->state
= TASK_DEAD
;
1054 /* Avoid "noreturn function does return". */
1056 cpu_relax(); /* For when BUG is null */
1059 EXPORT_SYMBOL_GPL(do_exit
);
1061 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1069 EXPORT_SYMBOL(complete_and_exit
);
1071 SYSCALL_DEFINE1(exit
, int, error_code
)
1073 do_exit((error_code
&0xff)<<8);
1077 * Take down every thread in the group. This is called by fatal signals
1078 * as well as by sys_exit_group (below).
1081 do_group_exit(int exit_code
)
1083 struct signal_struct
*sig
= current
->signal
;
1085 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1087 if (signal_group_exit(sig
))
1088 exit_code
= sig
->group_exit_code
;
1089 else if (!thread_group_empty(current
)) {
1090 struct sighand_struct
*const sighand
= current
->sighand
;
1091 spin_lock_irq(&sighand
->siglock
);
1092 if (signal_group_exit(sig
))
1093 /* Another thread got here before we took the lock. */
1094 exit_code
= sig
->group_exit_code
;
1096 sig
->group_exit_code
= exit_code
;
1097 sig
->flags
= SIGNAL_GROUP_EXIT
;
1098 zap_other_threads(current
);
1100 spin_unlock_irq(&sighand
->siglock
);
1108 * this kills every thread in the thread group. Note that any externally
1109 * wait4()-ing process will get the correct exit code - even if this
1110 * thread is not the thread group leader.
1112 SYSCALL_DEFINE1(exit_group
, int, error_code
)
1114 do_group_exit((error_code
& 0xff) << 8);
1120 enum pid_type wo_type
;
1124 struct siginfo __user
*wo_info
;
1125 int __user
*wo_stat
;
1126 struct rusage __user
*wo_rusage
;
1128 wait_queue_t child_wait
;
1133 struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1135 if (type
!= PIDTYPE_PID
)
1136 task
= task
->group_leader
;
1137 return task
->pids
[type
].pid
;
1140 static int eligible_pid(struct wait_opts
*wo
, struct task_struct
*p
)
1142 return wo
->wo_type
== PIDTYPE_MAX
||
1143 task_pid_type(p
, wo
->wo_type
) == wo
->wo_pid
;
1146 static int eligible_child(struct wait_opts
*wo
, struct task_struct
*p
)
1148 if (!eligible_pid(wo
, p
))
1150 /* Wait for all children (clone and not) if __WALL is set;
1151 * otherwise, wait for clone children *only* if __WCLONE is
1152 * set; otherwise, wait for non-clone children *only*. (Note:
1153 * A "clone" child here is one that reports to its parent
1154 * using a signal other than SIGCHLD.) */
1155 if (((p
->exit_signal
!= SIGCHLD
) ^ !!(wo
->wo_flags
& __WCLONE
))
1156 && !(wo
->wo_flags
& __WALL
))
1162 static int wait_noreap_copyout(struct wait_opts
*wo
, struct task_struct
*p
,
1163 pid_t pid
, uid_t uid
, int why
, int status
)
1165 struct siginfo __user
*infop
;
1166 int retval
= wo
->wo_rusage
1167 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1170 infop
= wo
->wo_info
;
1173 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1175 retval
= put_user(0, &infop
->si_errno
);
1177 retval
= put_user((short)why
, &infop
->si_code
);
1179 retval
= put_user(pid
, &infop
->si_pid
);
1181 retval
= put_user(uid
, &infop
->si_uid
);
1183 retval
= put_user(status
, &infop
->si_status
);
1191 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1192 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1193 * the lock and this task is uninteresting. If we return nonzero, we have
1194 * released the lock and the system call should return.
1196 static int wait_task_zombie(struct wait_opts
*wo
, struct task_struct
*p
)
1198 unsigned long state
;
1199 int retval
, status
, traced
;
1200 pid_t pid
= task_pid_vnr(p
);
1201 uid_t uid
= __task_cred(p
)->uid
;
1202 struct siginfo __user
*infop
;
1204 if (!likely(wo
->wo_flags
& WEXITED
))
1207 if (unlikely(wo
->wo_flags
& WNOWAIT
)) {
1208 int exit_code
= p
->exit_code
;
1212 read_unlock(&tasklist_lock
);
1213 if ((exit_code
& 0x7f) == 0) {
1215 status
= exit_code
>> 8;
1217 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1218 status
= exit_code
& 0x7f;
1220 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, status
);
1224 * Try to move the task's state to DEAD
1225 * only one thread is allowed to do this:
1227 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1228 if (state
!= EXIT_ZOMBIE
) {
1229 BUG_ON(state
!= EXIT_DEAD
);
1233 traced
= ptrace_reparented(p
);
1235 * It can be ptraced but not reparented, check
1236 * !task_detached() to filter out sub-threads.
1238 if (likely(!traced
) && likely(!task_detached(p
))) {
1239 struct signal_struct
*psig
;
1240 struct signal_struct
*sig
;
1241 unsigned long maxrss
;
1242 cputime_t tgutime
, tgstime
;
1245 * The resource counters for the group leader are in its
1246 * own task_struct. Those for dead threads in the group
1247 * are in its signal_struct, as are those for the child
1248 * processes it has previously reaped. All these
1249 * accumulate in the parent's signal_struct c* fields.
1251 * We don't bother to take a lock here to protect these
1252 * p->signal fields, because they are only touched by
1253 * __exit_signal, which runs with tasklist_lock
1254 * write-locked anyway, and so is excluded here. We do
1255 * need to protect the access to parent->signal fields,
1256 * as other threads in the parent group can be right
1257 * here reaping other children at the same time.
1259 * We use thread_group_times() to get times for the thread
1260 * group, which consolidates times for all threads in the
1261 * group including the group leader.
1263 thread_group_times(p
, &tgutime
, &tgstime
);
1264 spin_lock_irq(&p
->real_parent
->sighand
->siglock
);
1265 psig
= p
->real_parent
->signal
;
1268 cputime_add(psig
->cutime
,
1269 cputime_add(tgutime
,
1272 cputime_add(psig
->cstime
,
1273 cputime_add(tgstime
,
1276 cputime_add(psig
->cgtime
,
1277 cputime_add(p
->gtime
,
1278 cputime_add(sig
->gtime
,
1281 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1283 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1285 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1287 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1289 task_io_get_inblock(p
) +
1290 sig
->inblock
+ sig
->cinblock
;
1292 task_io_get_oublock(p
) +
1293 sig
->oublock
+ sig
->coublock
;
1294 maxrss
= max(sig
->maxrss
, sig
->cmaxrss
);
1295 if (psig
->cmaxrss
< maxrss
)
1296 psig
->cmaxrss
= maxrss
;
1297 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1298 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1299 spin_unlock_irq(&p
->real_parent
->sighand
->siglock
);
1303 * Now we are sure this task is interesting, and no other
1304 * thread can reap it because we set its state to EXIT_DEAD.
1306 read_unlock(&tasklist_lock
);
1308 retval
= wo
->wo_rusage
1309 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1310 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1311 ? p
->signal
->group_exit_code
: p
->exit_code
;
1312 if (!retval
&& wo
->wo_stat
)
1313 retval
= put_user(status
, wo
->wo_stat
);
1315 infop
= wo
->wo_info
;
1316 if (!retval
&& infop
)
1317 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1318 if (!retval
&& infop
)
1319 retval
= put_user(0, &infop
->si_errno
);
1320 if (!retval
&& infop
) {
1323 if ((status
& 0x7f) == 0) {
1327 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1330 retval
= put_user((short)why
, &infop
->si_code
);
1332 retval
= put_user(status
, &infop
->si_status
);
1334 if (!retval
&& infop
)
1335 retval
= put_user(pid
, &infop
->si_pid
);
1336 if (!retval
&& infop
)
1337 retval
= put_user(uid
, &infop
->si_uid
);
1342 write_lock_irq(&tasklist_lock
);
1343 /* We dropped tasklist, ptracer could die and untrace */
1346 * If this is not a detached task, notify the parent.
1347 * If it's still not detached after that, don't release
1350 if (!task_detached(p
)) {
1351 do_notify_parent(p
, p
->exit_signal
);
1352 if (!task_detached(p
)) {
1353 p
->exit_state
= EXIT_ZOMBIE
;
1357 write_unlock_irq(&tasklist_lock
);
1365 static int *task_stopped_code(struct task_struct
*p
, bool ptrace
)
1368 if (task_is_stopped_or_traced(p
) &&
1369 !(p
->jobctl
& JOBCTL_LISTENING
))
1370 return &p
->exit_code
;
1372 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
)
1373 return &p
->signal
->group_exit_code
;
1379 * wait_task_stopped - Wait for %TASK_STOPPED or %TASK_TRACED
1381 * @ptrace: is the wait for ptrace
1382 * @p: task to wait for
1384 * Handle sys_wait4() work for %p in state %TASK_STOPPED or %TASK_TRACED.
1387 * read_lock(&tasklist_lock), which is released if return value is
1388 * non-zero. Also, grabs and releases @p->sighand->siglock.
1391 * 0 if wait condition didn't exist and search for other wait conditions
1392 * should continue. Non-zero return, -errno on failure and @p's pid on
1393 * success, implies that tasklist_lock is released and wait condition
1394 * search should terminate.
1396 static int wait_task_stopped(struct wait_opts
*wo
,
1397 int ptrace
, struct task_struct
*p
)
1399 struct siginfo __user
*infop
;
1400 int retval
, exit_code
, *p_code
, why
;
1401 uid_t uid
= 0; /* unneeded, required by compiler */
1405 * Traditionally we see ptrace'd stopped tasks regardless of options.
1407 if (!ptrace
&& !(wo
->wo_flags
& WUNTRACED
))
1410 if (!task_stopped_code(p
, ptrace
))
1414 spin_lock_irq(&p
->sighand
->siglock
);
1416 p_code
= task_stopped_code(p
, ptrace
);
1417 if (unlikely(!p_code
))
1420 exit_code
= *p_code
;
1424 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1429 spin_unlock_irq(&p
->sighand
->siglock
);
1434 * Now we are pretty sure this task is interesting.
1435 * Make sure it doesn't get reaped out from under us while we
1436 * give up the lock and then examine it below. We don't want to
1437 * keep holding onto the tasklist_lock while we call getrusage and
1438 * possibly take page faults for user memory.
1441 pid
= task_pid_vnr(p
);
1442 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1443 read_unlock(&tasklist_lock
);
1445 if (unlikely(wo
->wo_flags
& WNOWAIT
))
1446 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, exit_code
);
1448 retval
= wo
->wo_rusage
1449 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1450 if (!retval
&& wo
->wo_stat
)
1451 retval
= put_user((exit_code
<< 8) | 0x7f, wo
->wo_stat
);
1453 infop
= wo
->wo_info
;
1454 if (!retval
&& infop
)
1455 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1456 if (!retval
&& infop
)
1457 retval
= put_user(0, &infop
->si_errno
);
1458 if (!retval
&& infop
)
1459 retval
= put_user((short)why
, &infop
->si_code
);
1460 if (!retval
&& infop
)
1461 retval
= put_user(exit_code
, &infop
->si_status
);
1462 if (!retval
&& infop
)
1463 retval
= put_user(pid
, &infop
->si_pid
);
1464 if (!retval
&& infop
)
1465 retval
= put_user(uid
, &infop
->si_uid
);
1475 * Handle do_wait work for one task in a live, non-stopped state.
1476 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1477 * the lock and this task is uninteresting. If we return nonzero, we have
1478 * released the lock and the system call should return.
1480 static int wait_task_continued(struct wait_opts
*wo
, struct task_struct
*p
)
1486 if (!unlikely(wo
->wo_flags
& WCONTINUED
))
1489 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1492 spin_lock_irq(&p
->sighand
->siglock
);
1493 /* Re-check with the lock held. */
1494 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1495 spin_unlock_irq(&p
->sighand
->siglock
);
1498 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1499 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1501 spin_unlock_irq(&p
->sighand
->siglock
);
1503 pid
= task_pid_vnr(p
);
1505 read_unlock(&tasklist_lock
);
1508 retval
= wo
->wo_rusage
1509 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1511 if (!retval
&& wo
->wo_stat
)
1512 retval
= put_user(0xffff, wo
->wo_stat
);
1516 retval
= wait_noreap_copyout(wo
, p
, pid
, uid
,
1517 CLD_CONTINUED
, SIGCONT
);
1518 BUG_ON(retval
== 0);
1525 * Consider @p for a wait by @parent.
1527 * -ECHILD should be in ->notask_error before the first call.
1528 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1529 * Returns zero if the search for a child should continue;
1530 * then ->notask_error is 0 if @p is an eligible child,
1531 * or another error from security_task_wait(), or still -ECHILD.
1533 static int wait_consider_task(struct wait_opts
*wo
, int ptrace
,
1534 struct task_struct
*p
)
1536 int ret
= eligible_child(wo
, p
);
1540 ret
= security_task_wait(p
);
1541 if (unlikely(ret
< 0)) {
1543 * If we have not yet seen any eligible child,
1544 * then let this error code replace -ECHILD.
1545 * A permission error will give the user a clue
1546 * to look for security policy problems, rather
1547 * than for mysterious wait bugs.
1549 if (wo
->notask_error
)
1550 wo
->notask_error
= ret
;
1554 /* dead body doesn't have much to contribute */
1555 if (p
->exit_state
== EXIT_DEAD
)
1559 if (p
->exit_state
== EXIT_ZOMBIE
) {
1561 * A zombie ptracee is only visible to its ptracer.
1562 * Notification and reaping will be cascaded to the real
1563 * parent when the ptracer detaches.
1565 if (likely(!ptrace
) && unlikely(p
->ptrace
)) {
1566 /* it will become visible, clear notask_error */
1567 wo
->notask_error
= 0;
1571 /* we don't reap group leaders with subthreads */
1572 if (!delay_group_leader(p
))
1573 return wait_task_zombie(wo
, p
);
1576 * Allow access to stopped/continued state via zombie by
1577 * falling through. Clearing of notask_error is complex.
1581 * If WEXITED is set, notask_error should naturally be
1582 * cleared. If not, subset of WSTOPPED|WCONTINUED is set,
1583 * so, if there are live subthreads, there are events to
1584 * wait for. If all subthreads are dead, it's still safe
1585 * to clear - this function will be called again in finite
1586 * amount time once all the subthreads are released and
1587 * will then return without clearing.
1591 * Stopped state is per-task and thus can't change once the
1592 * target task dies. Only continued and exited can happen.
1593 * Clear notask_error if WCONTINUED | WEXITED.
1595 if (likely(!ptrace
) || (wo
->wo_flags
& (WCONTINUED
| WEXITED
)))
1596 wo
->notask_error
= 0;
1599 * If @p is ptraced by a task in its real parent's group,
1600 * hide group stop/continued state when looking at @p as
1601 * the real parent; otherwise, a single stop can be
1602 * reported twice as group and ptrace stops.
1604 * If a ptracer wants to distinguish the two events for its
1605 * own children, it should create a separate process which
1606 * takes the role of real parent.
1608 if (likely(!ptrace
) && p
->ptrace
&&
1609 same_thread_group(p
->parent
, p
->real_parent
))
1613 * @p is alive and it's gonna stop, continue or exit, so
1614 * there always is something to wait for.
1616 wo
->notask_error
= 0;
1620 * Wait for stopped. Depending on @ptrace, different stopped state
1621 * is used and the two don't interact with each other.
1623 ret
= wait_task_stopped(wo
, ptrace
, p
);
1628 * Wait for continued. There's only one continued state and the
1629 * ptracer can consume it which can confuse the real parent. Don't
1630 * use WCONTINUED from ptracer. You don't need or want it.
1632 return wait_task_continued(wo
, p
);
1636 * Do the work of do_wait() for one thread in the group, @tsk.
1638 * -ECHILD should be in ->notask_error before the first call.
1639 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1640 * Returns zero if the search for a child should continue; then
1641 * ->notask_error is 0 if there were any eligible children,
1642 * or another error from security_task_wait(), or still -ECHILD.
1644 static int do_wait_thread(struct wait_opts
*wo
, struct task_struct
*tsk
)
1646 struct task_struct
*p
;
1648 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1649 int ret
= wait_consider_task(wo
, 0, p
);
1657 static int ptrace_do_wait(struct wait_opts
*wo
, struct task_struct
*tsk
)
1659 struct task_struct
*p
;
1661 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1662 int ret
= wait_consider_task(wo
, 1, p
);
1670 static int child_wait_callback(wait_queue_t
*wait
, unsigned mode
,
1671 int sync
, void *key
)
1673 struct wait_opts
*wo
= container_of(wait
, struct wait_opts
,
1675 struct task_struct
*p
= key
;
1677 if (!eligible_pid(wo
, p
))
1680 if ((wo
->wo_flags
& __WNOTHREAD
) && wait
->private != p
->parent
)
1683 return default_wake_function(wait
, mode
, sync
, key
);
1686 void __wake_up_parent(struct task_struct
*p
, struct task_struct
*parent
)
1688 __wake_up_sync_key(&parent
->signal
->wait_chldexit
,
1689 TASK_INTERRUPTIBLE
, 1, p
);
1692 static long do_wait(struct wait_opts
*wo
)
1694 struct task_struct
*tsk
;
1697 trace_sched_process_wait(wo
->wo_pid
);
1699 init_waitqueue_func_entry(&wo
->child_wait
, child_wait_callback
);
1700 wo
->child_wait
.private = current
;
1701 add_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1704 * If there is nothing that can match our critiera just get out.
1705 * We will clear ->notask_error to zero if we see any child that
1706 * might later match our criteria, even if we are not able to reap
1709 wo
->notask_error
= -ECHILD
;
1710 if ((wo
->wo_type
< PIDTYPE_MAX
) &&
1711 (!wo
->wo_pid
|| hlist_empty(&wo
->wo_pid
->tasks
[wo
->wo_type
])))
1714 set_current_state(TASK_INTERRUPTIBLE
);
1715 read_lock(&tasklist_lock
);
1718 retval
= do_wait_thread(wo
, tsk
);
1722 retval
= ptrace_do_wait(wo
, tsk
);
1726 if (wo
->wo_flags
& __WNOTHREAD
)
1728 } while_each_thread(current
, tsk
);
1729 read_unlock(&tasklist_lock
);
1732 retval
= wo
->notask_error
;
1733 if (!retval
&& !(wo
->wo_flags
& WNOHANG
)) {
1734 retval
= -ERESTARTSYS
;
1735 if (!signal_pending(current
)) {
1741 __set_current_state(TASK_RUNNING
);
1742 remove_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1746 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1747 infop
, int, options
, struct rusage __user
*, ru
)
1749 struct wait_opts wo
;
1750 struct pid
*pid
= NULL
;
1754 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1756 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1769 type
= PIDTYPE_PGID
;
1777 if (type
< PIDTYPE_MAX
)
1778 pid
= find_get_pid(upid
);
1782 wo
.wo_flags
= options
;
1792 * For a WNOHANG return, clear out all the fields
1793 * we would set so the user can easily tell the
1797 ret
= put_user(0, &infop
->si_signo
);
1799 ret
= put_user(0, &infop
->si_errno
);
1801 ret
= put_user(0, &infop
->si_code
);
1803 ret
= put_user(0, &infop
->si_pid
);
1805 ret
= put_user(0, &infop
->si_uid
);
1807 ret
= put_user(0, &infop
->si_status
);
1812 /* avoid REGPARM breakage on x86: */
1813 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1817 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1818 int, options
, struct rusage __user
*, ru
)
1820 struct wait_opts wo
;
1821 struct pid
*pid
= NULL
;
1825 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1826 __WNOTHREAD
|__WCLONE
|__WALL
))
1831 else if (upid
< 0) {
1832 type
= PIDTYPE_PGID
;
1833 pid
= find_get_pid(-upid
);
1834 } else if (upid
== 0) {
1835 type
= PIDTYPE_PGID
;
1836 pid
= get_task_pid(current
, PIDTYPE_PGID
);
1837 } else /* upid > 0 */ {
1839 pid
= find_get_pid(upid
);
1844 wo
.wo_flags
= options
| WEXITED
;
1846 wo
.wo_stat
= stat_addr
;
1851 /* avoid REGPARM breakage on x86: */
1852 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1856 #ifdef __ARCH_WANT_SYS_WAITPID
1859 * sys_waitpid() remains for compatibility. waitpid() should be
1860 * implemented by calling sys_wait4() from libc.a.
1862 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1864 return sys_wait4(pid
, stat_addr
, options
, NULL
);