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>
54 #include <asm/uaccess.h>
55 #include <asm/unistd.h>
56 #include <asm/pgtable.h>
57 #include <asm/mmu_context.h>
58 #include "cred-internals.h"
60 static void exit_mm(struct task_struct
* tsk
);
62 static void __unhash_process(struct task_struct
*p
)
65 detach_pid(p
, PIDTYPE_PID
);
66 if (thread_group_leader(p
)) {
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 __get_cpu_var(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 struct sighand_struct
*sighand
;
86 BUG_ON(!atomic_read(&sig
->count
));
88 sighand
= rcu_dereference_check(tsk
->sighand
,
89 rcu_read_lock_held() ||
90 lockdep_tasklist_lock_is_held());
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
->utime
= cputime_add(sig
->utime
, tsk
->utime
);
117 sig
->stime
= cputime_add(sig
->stime
, tsk
->stime
);
118 sig
->gtime
= cputime_add(sig
->gtime
, tsk
->gtime
);
119 sig
->min_flt
+= tsk
->min_flt
;
120 sig
->maj_flt
+= tsk
->maj_flt
;
121 sig
->nvcsw
+= tsk
->nvcsw
;
122 sig
->nivcsw
+= tsk
->nivcsw
;
123 sig
->inblock
+= task_io_get_inblock(tsk
);
124 sig
->oublock
+= task_io_get_oublock(tsk
);
125 task_io_accounting_add(&sig
->ioac
, &tsk
->ioac
);
126 sig
->sum_sched_runtime
+= tsk
->se
.sum_exec_runtime
;
127 sig
= NULL
; /* Marker for below. */
130 __unhash_process(tsk
);
133 * Do this under ->siglock, we can race with another thread
134 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
136 flush_sigqueue(&tsk
->pending
);
140 spin_unlock(&sighand
->siglock
);
142 __cleanup_sighand(sighand
);
143 clear_tsk_thread_flag(tsk
,TIF_SIGPENDING
);
145 flush_sigqueue(&sig
->shared_pending
);
146 taskstats_tgid_free(sig
);
148 * Make sure ->signal can't go away under rq->lock,
149 * see account_group_exec_runtime().
151 task_rq_unlock_wait(tsk
);
152 __cleanup_signal(sig
);
156 static void delayed_put_task_struct(struct rcu_head
*rhp
)
158 struct task_struct
*tsk
= container_of(rhp
, struct task_struct
, rcu
);
160 #ifdef CONFIG_PERF_EVENTS
161 WARN_ON_ONCE(tsk
->perf_event_ctxp
);
163 trace_sched_process_free(tsk
);
164 put_task_struct(tsk
);
168 void release_task(struct task_struct
* p
)
170 struct task_struct
*leader
;
173 tracehook_prepare_release_task(p
);
174 /* don't need to get the RCU readlock here - the process is dead and
175 * can't be modifying its own credentials. But shut RCU-lockdep up */
177 atomic_dec(&__task_cred(p
)->user
->processes
);
182 write_lock_irq(&tasklist_lock
);
183 tracehook_finish_release_task(p
);
187 * If we are the last non-leader member of the thread
188 * group, and the leader is zombie, then notify the
189 * group leader's parent process. (if it wants notification.)
192 leader
= p
->group_leader
;
193 if (leader
!= p
&& thread_group_empty(leader
) && leader
->exit_state
== EXIT_ZOMBIE
) {
194 BUG_ON(task_detached(leader
));
195 do_notify_parent(leader
, leader
->exit_signal
);
197 * If we were the last child thread and the leader has
198 * exited already, and the leader's parent ignores SIGCHLD,
199 * then we are the one who should release the leader.
201 * do_notify_parent() will have marked it self-reaping in
204 zap_leader
= task_detached(leader
);
207 * This maintains the invariant that release_task()
208 * only runs on a task in EXIT_DEAD, just for sanity.
211 leader
->exit_state
= EXIT_DEAD
;
214 write_unlock_irq(&tasklist_lock
);
216 call_rcu(&p
->rcu
, delayed_put_task_struct
);
219 if (unlikely(zap_leader
))
224 * This checks not only the pgrp, but falls back on the pid if no
225 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
228 * The caller must hold rcu lock or the tasklist lock.
230 struct pid
*session_of_pgrp(struct pid
*pgrp
)
232 struct task_struct
*p
;
233 struct pid
*sid
= NULL
;
235 p
= pid_task(pgrp
, PIDTYPE_PGID
);
237 p
= pid_task(pgrp
, PIDTYPE_PID
);
239 sid
= task_session(p
);
245 * Determine if a process group is "orphaned", according to the POSIX
246 * definition in 2.2.2.52. Orphaned process groups are not to be affected
247 * by terminal-generated stop signals. Newly orphaned process groups are
248 * to receive a SIGHUP and a SIGCONT.
250 * "I ask you, have you ever known what it is to be an orphan?"
252 static int will_become_orphaned_pgrp(struct pid
*pgrp
, struct task_struct
*ignored_task
)
254 struct task_struct
*p
;
256 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
257 if ((p
== ignored_task
) ||
258 (p
->exit_state
&& thread_group_empty(p
)) ||
259 is_global_init(p
->real_parent
))
262 if (task_pgrp(p
->real_parent
) != pgrp
&&
263 task_session(p
->real_parent
) == task_session(p
))
265 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
270 int is_current_pgrp_orphaned(void)
274 read_lock(&tasklist_lock
);
275 retval
= will_become_orphaned_pgrp(task_pgrp(current
), NULL
);
276 read_unlock(&tasklist_lock
);
281 static int has_stopped_jobs(struct pid
*pgrp
)
284 struct task_struct
*p
;
286 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
287 if (!task_is_stopped(p
))
291 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
296 * Check to see if any process groups have become orphaned as
297 * a result of our exiting, and if they have any stopped jobs,
298 * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
301 kill_orphaned_pgrp(struct task_struct
*tsk
, struct task_struct
*parent
)
303 struct pid
*pgrp
= task_pgrp(tsk
);
304 struct task_struct
*ignored_task
= tsk
;
307 /* exit: our father is in a different pgrp than
308 * we are and we were the only connection outside.
310 parent
= tsk
->real_parent
;
312 /* reparent: our child is in a different pgrp than
313 * we are, and it was the only connection outside.
317 if (task_pgrp(parent
) != pgrp
&&
318 task_session(parent
) == task_session(tsk
) &&
319 will_become_orphaned_pgrp(pgrp
, ignored_task
) &&
320 has_stopped_jobs(pgrp
)) {
321 __kill_pgrp_info(SIGHUP
, SEND_SIG_PRIV
, pgrp
);
322 __kill_pgrp_info(SIGCONT
, SEND_SIG_PRIV
, pgrp
);
327 * reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
329 * If a kernel thread is launched as a result of a system call, or if
330 * it ever exits, it should generally reparent itself to kthreadd so it
331 * isn't in the way of other processes and is correctly cleaned up on exit.
333 * The various task state such as scheduling policy and priority may have
334 * been inherited from a user process, so we reset them to sane values here.
336 * NOTE that reparent_to_kthreadd() gives the caller full capabilities.
338 static void reparent_to_kthreadd(void)
340 write_lock_irq(&tasklist_lock
);
342 ptrace_unlink(current
);
343 /* Reparent to init */
344 current
->real_parent
= current
->parent
= kthreadd_task
;
345 list_move_tail(¤t
->sibling
, ¤t
->real_parent
->children
);
347 /* Set the exit signal to SIGCHLD so we signal init on exit */
348 current
->exit_signal
= SIGCHLD
;
350 if (task_nice(current
) < 0)
351 set_user_nice(current
, 0);
355 memcpy(current
->signal
->rlim
, init_task
.signal
->rlim
,
356 sizeof(current
->signal
->rlim
));
358 atomic_inc(&init_cred
.usage
);
359 commit_creds(&init_cred
);
360 write_unlock_irq(&tasklist_lock
);
363 void __set_special_pids(struct pid
*pid
)
365 struct task_struct
*curr
= current
->group_leader
;
367 if (task_session(curr
) != pid
)
368 change_pid(curr
, PIDTYPE_SID
, pid
);
370 if (task_pgrp(curr
) != pid
)
371 change_pid(curr
, PIDTYPE_PGID
, pid
);
374 static void set_special_pids(struct pid
*pid
)
376 write_lock_irq(&tasklist_lock
);
377 __set_special_pids(pid
);
378 write_unlock_irq(&tasklist_lock
);
382 * Let kernel threads use this to say that they allow a certain signal.
383 * Must not be used if kthread was cloned with CLONE_SIGHAND.
385 int allow_signal(int sig
)
387 if (!valid_signal(sig
) || sig
< 1)
390 spin_lock_irq(¤t
->sighand
->siglock
);
391 /* This is only needed for daemonize()'ed kthreads */
392 sigdelset(¤t
->blocked
, sig
);
394 * Kernel threads handle their own signals. Let the signal code
395 * know it'll be handled, so that they don't get converted to
396 * SIGKILL or just silently dropped.
398 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= (void __user
*)2;
400 spin_unlock_irq(¤t
->sighand
->siglock
);
404 EXPORT_SYMBOL(allow_signal
);
406 int disallow_signal(int sig
)
408 if (!valid_signal(sig
) || sig
< 1)
411 spin_lock_irq(¤t
->sighand
->siglock
);
412 current
->sighand
->action
[(sig
)-1].sa
.sa_handler
= SIG_IGN
;
414 spin_unlock_irq(¤t
->sighand
->siglock
);
418 EXPORT_SYMBOL(disallow_signal
);
421 * Put all the gunge required to become a kernel thread without
422 * attached user resources in one place where it belongs.
425 void daemonize(const char *name
, ...)
430 va_start(args
, name
);
431 vsnprintf(current
->comm
, sizeof(current
->comm
), name
, args
);
435 * If we were started as result of loading a module, close all of the
436 * user space pages. We don't need them, and if we didn't close them
437 * they would be locked into memory.
441 * We don't want to have TIF_FREEZE set if the system-wide hibernation
442 * or suspend transition begins right now.
444 current
->flags
|= (PF_NOFREEZE
| PF_KTHREAD
);
446 if (current
->nsproxy
!= &init_nsproxy
) {
447 get_nsproxy(&init_nsproxy
);
448 switch_task_namespaces(current
, &init_nsproxy
);
450 set_special_pids(&init_struct_pid
);
451 proc_clear_tty(current
);
453 /* Block and flush all signals */
454 sigfillset(&blocked
);
455 sigprocmask(SIG_BLOCK
, &blocked
, NULL
);
456 flush_signals(current
);
458 /* Become as one with the init task */
460 daemonize_fs_struct();
462 current
->files
= init_task
.files
;
463 atomic_inc(¤t
->files
->count
);
465 reparent_to_kthreadd();
468 EXPORT_SYMBOL(daemonize
);
470 static void close_files(struct files_struct
* files
)
478 * It is safe to dereference the fd table without RCU or
479 * ->file_lock because this is the last reference to the
480 * files structure. But use RCU to shut RCU-lockdep up.
483 fdt
= files_fdtable(files
);
488 if (i
>= fdt
->max_fds
)
490 set
= fdt
->open_fds
->fds_bits
[j
++];
493 struct file
* file
= xchg(&fdt
->fd
[i
], NULL
);
495 filp_close(file
, files
);
505 struct files_struct
*get_files_struct(struct task_struct
*task
)
507 struct files_struct
*files
;
512 atomic_inc(&files
->count
);
518 void put_files_struct(struct files_struct
*files
)
522 if (atomic_dec_and_test(&files
->count
)) {
525 * Free the fd and fdset arrays if we expanded them.
526 * If the fdtable was embedded, pass files for freeing
527 * at the end of the RCU grace period. Otherwise,
528 * you can free files immediately.
531 fdt
= files_fdtable(files
);
532 if (fdt
!= &files
->fdtab
)
533 kmem_cache_free(files_cachep
, files
);
539 void reset_files_struct(struct files_struct
*files
)
541 struct task_struct
*tsk
= current
;
542 struct files_struct
*old
;
548 put_files_struct(old
);
551 void exit_files(struct task_struct
*tsk
)
553 struct files_struct
* files
= tsk
->files
;
559 put_files_struct(files
);
563 #ifdef CONFIG_MM_OWNER
565 * Task p is exiting and it owned mm, lets find a new owner for it
568 mm_need_new_owner(struct mm_struct
*mm
, struct task_struct
*p
)
571 * If there are other users of the mm and the owner (us) is exiting
572 * we need to find a new owner to take on the responsibility.
574 if (atomic_read(&mm
->mm_users
) <= 1)
581 void mm_update_next_owner(struct mm_struct
*mm
)
583 struct task_struct
*c
, *g
, *p
= current
;
586 if (!mm_need_new_owner(mm
, p
))
589 read_lock(&tasklist_lock
);
591 * Search in the children
593 list_for_each_entry(c
, &p
->children
, sibling
) {
595 goto assign_new_owner
;
599 * Search in the siblings
601 list_for_each_entry(c
, &p
->real_parent
->children
, sibling
) {
603 goto assign_new_owner
;
607 * Search through everything else. We should not get
610 do_each_thread(g
, c
) {
612 goto assign_new_owner
;
613 } while_each_thread(g
, c
);
615 read_unlock(&tasklist_lock
);
617 * We found no owner yet mm_users > 1: this implies that we are
618 * most likely racing with swapoff (try_to_unuse()) or /proc or
619 * ptrace or page migration (get_task_mm()). Mark owner as NULL.
628 * The task_lock protects c->mm from changing.
629 * We always want mm->owner->mm == mm
633 * Delay read_unlock() till we have the task_lock()
634 * to ensure that c does not slip away underneath us
636 read_unlock(&tasklist_lock
);
646 #endif /* CONFIG_MM_OWNER */
649 * Turn us into a lazy TLB process if we
652 static void exit_mm(struct task_struct
* tsk
)
654 struct mm_struct
*mm
= tsk
->mm
;
655 struct core_state
*core_state
;
661 * Serialize with any possible pending coredump.
662 * We must hold mmap_sem around checking core_state
663 * and clearing tsk->mm. The core-inducing thread
664 * will increment ->nr_threads for each thread in the
665 * group with ->mm != NULL.
667 down_read(&mm
->mmap_sem
);
668 core_state
= mm
->core_state
;
670 struct core_thread self
;
671 up_read(&mm
->mmap_sem
);
674 self
.next
= xchg(&core_state
->dumper
.next
, &self
);
676 * Implies mb(), the result of xchg() must be visible
677 * to core_state->dumper.
679 if (atomic_dec_and_test(&core_state
->nr_threads
))
680 complete(&core_state
->startup
);
683 set_task_state(tsk
, TASK_UNINTERRUPTIBLE
);
684 if (!self
.task
) /* see coredump_finish() */
688 __set_task_state(tsk
, TASK_RUNNING
);
689 down_read(&mm
->mmap_sem
);
691 atomic_inc(&mm
->mm_count
);
692 BUG_ON(mm
!= tsk
->active_mm
);
693 /* more a memory barrier than a real lock */
696 up_read(&mm
->mmap_sem
);
697 enter_lazy_tlb(mm
, current
);
698 /* We don't want this task to be frozen prematurely */
699 clear_freeze_flag(tsk
);
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
)
714 struct pid_namespace
*pid_ns
= task_active_pid_ns(father
);
715 struct task_struct
*thread
;
718 while_each_thread(father
, thread
) {
719 if (thread
->flags
& PF_EXITING
)
721 if (unlikely(pid_ns
->child_reaper
== father
))
722 pid_ns
->child_reaper
= thread
;
726 if (unlikely(pid_ns
->child_reaper
== father
)) {
727 write_unlock_irq(&tasklist_lock
);
728 if (unlikely(pid_ns
== &init_pid_ns
))
729 panic("Attempted to kill init!");
731 zap_pid_ns_processes(pid_ns
);
732 write_lock_irq(&tasklist_lock
);
734 * We can not clear ->child_reaper or leave it alone.
735 * There may by stealth EXIT_DEAD tasks on ->children,
736 * forget_original_parent() must move them somewhere.
738 pid_ns
->child_reaper
= init_pid_ns
.child_reaper
;
741 return pid_ns
->child_reaper
;
745 * Any that need to be release_task'd are put on the @dead list.
747 static void reparent_leader(struct task_struct
*father
, struct task_struct
*p
,
748 struct list_head
*dead
)
750 list_move_tail(&p
->sibling
, &p
->real_parent
->children
);
752 if (task_detached(p
))
755 * If this is a threaded reparent there is no need to
756 * notify anyone anything has happened.
758 if (same_thread_group(p
->real_parent
, father
))
761 /* We don't want people slaying init. */
762 p
->exit_signal
= SIGCHLD
;
764 /* If it has exited notify the new parent about this child's death. */
765 if (!task_ptrace(p
) &&
766 p
->exit_state
== EXIT_ZOMBIE
&& thread_group_empty(p
)) {
767 do_notify_parent(p
, p
->exit_signal
);
768 if (task_detached(p
)) {
769 p
->exit_state
= EXIT_DEAD
;
770 list_move_tail(&p
->sibling
, dead
);
774 kill_orphaned_pgrp(p
, father
);
777 static void forget_original_parent(struct task_struct
*father
)
779 struct task_struct
*p
, *n
, *reaper
;
780 LIST_HEAD(dead_children
);
784 write_lock_irq(&tasklist_lock
);
785 reaper
= find_new_reaper(father
);
787 list_for_each_entry_safe(p
, n
, &father
->children
, sibling
) {
788 struct task_struct
*t
= p
;
790 t
->real_parent
= reaper
;
791 if (t
->parent
== father
) {
792 BUG_ON(task_ptrace(t
));
793 t
->parent
= t
->real_parent
;
795 if (t
->pdeath_signal
)
796 group_send_sig_info(t
->pdeath_signal
,
798 } while_each_thread(p
, t
);
799 reparent_leader(father
, p
, &dead_children
);
801 write_unlock_irq(&tasklist_lock
);
803 BUG_ON(!list_empty(&father
->children
));
805 list_for_each_entry_safe(p
, n
, &dead_children
, sibling
) {
806 list_del_init(&p
->sibling
);
812 * Send signals to all our closest relatives so that they know
813 * to properly mourn us..
815 static void exit_notify(struct task_struct
*tsk
, int group_dead
)
821 * This does two things:
823 * A. Make init inherit all the child processes
824 * B. Check to see if any process groups have become orphaned
825 * as a result of our exiting, and if they have any stopped
826 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
828 forget_original_parent(tsk
);
829 exit_task_namespaces(tsk
);
831 write_lock_irq(&tasklist_lock
);
833 kill_orphaned_pgrp(tsk
->group_leader
, NULL
);
835 /* Let father know we died
837 * Thread signals are configurable, but you aren't going to use
838 * that to send signals to arbitary processes.
839 * That stops right now.
841 * If the parent exec id doesn't match the exec id we saved
842 * when we started then we know the parent has changed security
845 * If our self_exec id doesn't match our parent_exec_id then
846 * we have changed execution domain as these two values started
847 * the same after a fork.
849 if (tsk
->exit_signal
!= SIGCHLD
&& !task_detached(tsk
) &&
850 (tsk
->parent_exec_id
!= tsk
->real_parent
->self_exec_id
||
851 tsk
->self_exec_id
!= tsk
->parent_exec_id
))
852 tsk
->exit_signal
= SIGCHLD
;
854 signal
= tracehook_notify_death(tsk
, &cookie
, group_dead
);
856 signal
= do_notify_parent(tsk
, signal
);
858 tsk
->exit_state
= signal
== DEATH_REAP
? EXIT_DEAD
: EXIT_ZOMBIE
;
860 /* mt-exec, de_thread() is waiting for us */
861 if (thread_group_leader(tsk
) &&
862 tsk
->signal
->group_exit_task
&&
863 tsk
->signal
->notify_count
< 0)
864 wake_up_process(tsk
->signal
->group_exit_task
);
866 write_unlock_irq(&tasklist_lock
);
868 tracehook_report_death(tsk
, signal
, cookie
, group_dead
);
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
));
909 if (unlikely(in_interrupt()))
910 panic("Aiee, killing interrupt handler!");
911 if (unlikely(!tsk
->pid
))
912 panic("Attempted to kill the idle task!");
914 tracehook_report_exit(&code
);
916 validate_creds_for_do_exit(tsk
);
919 * We're taking recursive faults here in do_exit. Safest is to just
920 * leave this task alone and wait for reboot.
922 if (unlikely(tsk
->flags
& PF_EXITING
)) {
924 "Fixing recursive fault but reboot is needed!\n");
926 * We can do this unlocked here. The futex code uses
927 * this flag just to verify whether the pi state
928 * cleanup has been done or not. In the worst case it
929 * loops once more. We pretend that the cleanup was
930 * done as there is no way to return. Either the
931 * OWNER_DIED bit is set by now or we push the blocked
932 * task into the wait for ever nirwana as well.
934 tsk
->flags
|= PF_EXITPIDONE
;
935 set_current_state(TASK_UNINTERRUPTIBLE
);
941 exit_signals(tsk
); /* sets PF_EXITING */
943 * tsk->flags are checked in the futex code to protect against
944 * an exiting task cleaning up the robust pi futexes.
947 raw_spin_unlock_wait(&tsk
->pi_lock
);
949 if (unlikely(in_atomic()))
950 printk(KERN_INFO
"note: %s[%d] exited with preempt_count %d\n",
951 current
->comm
, task_pid_nr(current
),
954 acct_update_integrals(tsk
);
955 /* sync mm's RSS info before statistics gathering */
957 sync_mm_rss(tsk
, tsk
->mm
);
958 group_dead
= atomic_dec_and_test(&tsk
->signal
->live
);
960 hrtimer_cancel(&tsk
->signal
->real_timer
);
961 exit_itimers(tsk
->signal
);
963 setmax_mm_hiwater_rss(&tsk
->signal
->maxrss
, tsk
->mm
);
965 acct_collect(code
, group_dead
);
968 if (unlikely(tsk
->audit_context
))
971 tsk
->exit_code
= code
;
972 taskstats_exit(tsk
, group_dead
);
978 trace_sched_process_exit(tsk
);
988 disassociate_ctty(1);
990 module_put(task_thread_info(tsk
)->exec_domain
->module
);
992 proc_exit_connector(tsk
);
995 * FIXME: do that only when needed, using sched_exit tracepoint
997 flush_ptrace_hw_breakpoint(tsk
);
999 * Flush inherited counters to the parent - before the parent
1000 * gets woken up by child-exit notifications.
1002 perf_event_exit_task(tsk
);
1004 exit_notify(tsk
, group_dead
);
1006 mpol_put(tsk
->mempolicy
);
1007 tsk
->mempolicy
= NULL
;
1010 if (unlikely(current
->pi_state_cache
))
1011 kfree(current
->pi_state_cache
);
1014 * Make sure we are holding no locks:
1016 debug_check_no_locks_held(tsk
);
1018 * We can do this unlocked here. The futex code uses this flag
1019 * just to verify whether the pi state cleanup has been done
1020 * or not. In the worst case it loops once more.
1022 tsk
->flags
|= PF_EXITPIDONE
;
1024 if (tsk
->io_context
)
1025 exit_io_context(tsk
);
1027 if (tsk
->splice_pipe
)
1028 __free_pipe_info(tsk
->splice_pipe
);
1030 validate_creds_for_do_exit(tsk
);
1034 /* causes final put_task_struct in finish_task_switch(). */
1035 tsk
->state
= TASK_DEAD
;
1038 /* Avoid "noreturn function does return". */
1040 cpu_relax(); /* For when BUG is null */
1043 EXPORT_SYMBOL_GPL(do_exit
);
1045 NORET_TYPE
void complete_and_exit(struct completion
*comp
, long code
)
1053 EXPORT_SYMBOL(complete_and_exit
);
1055 SYSCALL_DEFINE1(exit
, int, error_code
)
1057 do_exit((error_code
&0xff)<<8);
1061 * Take down every thread in the group. This is called by fatal signals
1062 * as well as by sys_exit_group (below).
1065 do_group_exit(int exit_code
)
1067 struct signal_struct
*sig
= current
->signal
;
1069 BUG_ON(exit_code
& 0x80); /* core dumps don't get here */
1071 if (signal_group_exit(sig
))
1072 exit_code
= sig
->group_exit_code
;
1073 else if (!thread_group_empty(current
)) {
1074 struct sighand_struct
*const sighand
= current
->sighand
;
1075 spin_lock_irq(&sighand
->siglock
);
1076 if (signal_group_exit(sig
))
1077 /* Another thread got here before we took the lock. */
1078 exit_code
= sig
->group_exit_code
;
1080 sig
->group_exit_code
= exit_code
;
1081 sig
->flags
= SIGNAL_GROUP_EXIT
;
1082 zap_other_threads(current
);
1084 spin_unlock_irq(&sighand
->siglock
);
1092 * this kills every thread in the thread group. Note that any externally
1093 * wait4()-ing process will get the correct exit code - even if this
1094 * thread is not the thread group leader.
1096 SYSCALL_DEFINE1(exit_group
, int, error_code
)
1098 do_group_exit((error_code
& 0xff) << 8);
1104 enum pid_type wo_type
;
1108 struct siginfo __user
*wo_info
;
1109 int __user
*wo_stat
;
1110 struct rusage __user
*wo_rusage
;
1112 wait_queue_t child_wait
;
1117 struct pid
*task_pid_type(struct task_struct
*task
, enum pid_type type
)
1119 if (type
!= PIDTYPE_PID
)
1120 task
= task
->group_leader
;
1121 return task
->pids
[type
].pid
;
1124 static int eligible_pid(struct wait_opts
*wo
, struct task_struct
*p
)
1126 return wo
->wo_type
== PIDTYPE_MAX
||
1127 task_pid_type(p
, wo
->wo_type
) == wo
->wo_pid
;
1130 static int eligible_child(struct wait_opts
*wo
, struct task_struct
*p
)
1132 if (!eligible_pid(wo
, p
))
1134 /* Wait for all children (clone and not) if __WALL is set;
1135 * otherwise, wait for clone children *only* if __WCLONE is
1136 * set; otherwise, wait for non-clone children *only*. (Note:
1137 * A "clone" child here is one that reports to its parent
1138 * using a signal other than SIGCHLD.) */
1139 if (((p
->exit_signal
!= SIGCHLD
) ^ !!(wo
->wo_flags
& __WCLONE
))
1140 && !(wo
->wo_flags
& __WALL
))
1146 static int wait_noreap_copyout(struct wait_opts
*wo
, struct task_struct
*p
,
1147 pid_t pid
, uid_t uid
, int why
, int status
)
1149 struct siginfo __user
*infop
;
1150 int retval
= wo
->wo_rusage
1151 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1154 infop
= wo
->wo_info
;
1157 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1159 retval
= put_user(0, &infop
->si_errno
);
1161 retval
= put_user((short)why
, &infop
->si_code
);
1163 retval
= put_user(pid
, &infop
->si_pid
);
1165 retval
= put_user(uid
, &infop
->si_uid
);
1167 retval
= put_user(status
, &infop
->si_status
);
1175 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1176 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1177 * the lock and this task is uninteresting. If we return nonzero, we have
1178 * released the lock and the system call should return.
1180 static int wait_task_zombie(struct wait_opts
*wo
, struct task_struct
*p
)
1182 unsigned long state
;
1183 int retval
, status
, traced
;
1184 pid_t pid
= task_pid_vnr(p
);
1185 uid_t uid
= __task_cred(p
)->uid
;
1186 struct siginfo __user
*infop
;
1188 if (!likely(wo
->wo_flags
& WEXITED
))
1191 if (unlikely(wo
->wo_flags
& WNOWAIT
)) {
1192 int exit_code
= p
->exit_code
;
1196 read_unlock(&tasklist_lock
);
1197 if ((exit_code
& 0x7f) == 0) {
1199 status
= exit_code
>> 8;
1201 why
= (exit_code
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1202 status
= exit_code
& 0x7f;
1204 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, status
);
1208 * Try to move the task's state to DEAD
1209 * only one thread is allowed to do this:
1211 state
= xchg(&p
->exit_state
, EXIT_DEAD
);
1212 if (state
!= EXIT_ZOMBIE
) {
1213 BUG_ON(state
!= EXIT_DEAD
);
1217 traced
= ptrace_reparented(p
);
1219 * It can be ptraced but not reparented, check
1220 * !task_detached() to filter out sub-threads.
1222 if (likely(!traced
) && likely(!task_detached(p
))) {
1223 struct signal_struct
*psig
;
1224 struct signal_struct
*sig
;
1225 unsigned long maxrss
;
1226 cputime_t tgutime
, tgstime
;
1229 * The resource counters for the group leader are in its
1230 * own task_struct. Those for dead threads in the group
1231 * are in its signal_struct, as are those for the child
1232 * processes it has previously reaped. All these
1233 * accumulate in the parent's signal_struct c* fields.
1235 * We don't bother to take a lock here to protect these
1236 * p->signal fields, because they are only touched by
1237 * __exit_signal, which runs with tasklist_lock
1238 * write-locked anyway, and so is excluded here. We do
1239 * need to protect the access to parent->signal fields,
1240 * as other threads in the parent group can be right
1241 * here reaping other children at the same time.
1243 * We use thread_group_times() to get times for the thread
1244 * group, which consolidates times for all threads in the
1245 * group including the group leader.
1247 thread_group_times(p
, &tgutime
, &tgstime
);
1248 spin_lock_irq(&p
->real_parent
->sighand
->siglock
);
1249 psig
= p
->real_parent
->signal
;
1252 cputime_add(psig
->cutime
,
1253 cputime_add(tgutime
,
1256 cputime_add(psig
->cstime
,
1257 cputime_add(tgstime
,
1260 cputime_add(psig
->cgtime
,
1261 cputime_add(p
->gtime
,
1262 cputime_add(sig
->gtime
,
1265 p
->min_flt
+ sig
->min_flt
+ sig
->cmin_flt
;
1267 p
->maj_flt
+ sig
->maj_flt
+ sig
->cmaj_flt
;
1269 p
->nvcsw
+ sig
->nvcsw
+ sig
->cnvcsw
;
1271 p
->nivcsw
+ sig
->nivcsw
+ sig
->cnivcsw
;
1273 task_io_get_inblock(p
) +
1274 sig
->inblock
+ sig
->cinblock
;
1276 task_io_get_oublock(p
) +
1277 sig
->oublock
+ sig
->coublock
;
1278 maxrss
= max(sig
->maxrss
, sig
->cmaxrss
);
1279 if (psig
->cmaxrss
< maxrss
)
1280 psig
->cmaxrss
= maxrss
;
1281 task_io_accounting_add(&psig
->ioac
, &p
->ioac
);
1282 task_io_accounting_add(&psig
->ioac
, &sig
->ioac
);
1283 spin_unlock_irq(&p
->real_parent
->sighand
->siglock
);
1287 * Now we are sure this task is interesting, and no other
1288 * thread can reap it because we set its state to EXIT_DEAD.
1290 read_unlock(&tasklist_lock
);
1292 retval
= wo
->wo_rusage
1293 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1294 status
= (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1295 ? p
->signal
->group_exit_code
: p
->exit_code
;
1296 if (!retval
&& wo
->wo_stat
)
1297 retval
= put_user(status
, wo
->wo_stat
);
1299 infop
= wo
->wo_info
;
1300 if (!retval
&& infop
)
1301 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1302 if (!retval
&& infop
)
1303 retval
= put_user(0, &infop
->si_errno
);
1304 if (!retval
&& infop
) {
1307 if ((status
& 0x7f) == 0) {
1311 why
= (status
& 0x80) ? CLD_DUMPED
: CLD_KILLED
;
1314 retval
= put_user((short)why
, &infop
->si_code
);
1316 retval
= put_user(status
, &infop
->si_status
);
1318 if (!retval
&& infop
)
1319 retval
= put_user(pid
, &infop
->si_pid
);
1320 if (!retval
&& infop
)
1321 retval
= put_user(uid
, &infop
->si_uid
);
1326 write_lock_irq(&tasklist_lock
);
1327 /* We dropped tasklist, ptracer could die and untrace */
1330 * If this is not a detached task, notify the parent.
1331 * If it's still not detached after that, don't release
1334 if (!task_detached(p
)) {
1335 do_notify_parent(p
, p
->exit_signal
);
1336 if (!task_detached(p
)) {
1337 p
->exit_state
= EXIT_ZOMBIE
;
1341 write_unlock_irq(&tasklist_lock
);
1349 static int *task_stopped_code(struct task_struct
*p
, bool ptrace
)
1352 if (task_is_stopped_or_traced(p
))
1353 return &p
->exit_code
;
1355 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
)
1356 return &p
->signal
->group_exit_code
;
1362 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1363 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1364 * the lock and this task is uninteresting. If we return nonzero, we have
1365 * released the lock and the system call should return.
1367 static int wait_task_stopped(struct wait_opts
*wo
,
1368 int ptrace
, struct task_struct
*p
)
1370 struct siginfo __user
*infop
;
1371 int retval
, exit_code
, *p_code
, why
;
1372 uid_t uid
= 0; /* unneeded, required by compiler */
1376 * Traditionally we see ptrace'd stopped tasks regardless of options.
1378 if (!ptrace
&& !(wo
->wo_flags
& WUNTRACED
))
1382 spin_lock_irq(&p
->sighand
->siglock
);
1384 p_code
= task_stopped_code(p
, ptrace
);
1385 if (unlikely(!p_code
))
1388 exit_code
= *p_code
;
1392 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1395 /* don't need the RCU readlock here as we're holding a spinlock */
1396 uid
= __task_cred(p
)->uid
;
1398 spin_unlock_irq(&p
->sighand
->siglock
);
1403 * Now we are pretty sure this task is interesting.
1404 * Make sure it doesn't get reaped out from under us while we
1405 * give up the lock and then examine it below. We don't want to
1406 * keep holding onto the tasklist_lock while we call getrusage and
1407 * possibly take page faults for user memory.
1410 pid
= task_pid_vnr(p
);
1411 why
= ptrace
? CLD_TRAPPED
: CLD_STOPPED
;
1412 read_unlock(&tasklist_lock
);
1414 if (unlikely(wo
->wo_flags
& WNOWAIT
))
1415 return wait_noreap_copyout(wo
, p
, pid
, uid
, why
, exit_code
);
1417 retval
= wo
->wo_rusage
1418 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1419 if (!retval
&& wo
->wo_stat
)
1420 retval
= put_user((exit_code
<< 8) | 0x7f, wo
->wo_stat
);
1422 infop
= wo
->wo_info
;
1423 if (!retval
&& infop
)
1424 retval
= put_user(SIGCHLD
, &infop
->si_signo
);
1425 if (!retval
&& infop
)
1426 retval
= put_user(0, &infop
->si_errno
);
1427 if (!retval
&& infop
)
1428 retval
= put_user((short)why
, &infop
->si_code
);
1429 if (!retval
&& infop
)
1430 retval
= put_user(exit_code
, &infop
->si_status
);
1431 if (!retval
&& infop
)
1432 retval
= put_user(pid
, &infop
->si_pid
);
1433 if (!retval
&& infop
)
1434 retval
= put_user(uid
, &infop
->si_uid
);
1444 * Handle do_wait work for one task in a live, non-stopped state.
1445 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1446 * the lock and this task is uninteresting. If we return nonzero, we have
1447 * released the lock and the system call should return.
1449 static int wait_task_continued(struct wait_opts
*wo
, struct task_struct
*p
)
1455 if (!unlikely(wo
->wo_flags
& WCONTINUED
))
1458 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
))
1461 spin_lock_irq(&p
->sighand
->siglock
);
1462 /* Re-check with the lock held. */
1463 if (!(p
->signal
->flags
& SIGNAL_STOP_CONTINUED
)) {
1464 spin_unlock_irq(&p
->sighand
->siglock
);
1467 if (!unlikely(wo
->wo_flags
& WNOWAIT
))
1468 p
->signal
->flags
&= ~SIGNAL_STOP_CONTINUED
;
1469 uid
= __task_cred(p
)->uid
;
1470 spin_unlock_irq(&p
->sighand
->siglock
);
1472 pid
= task_pid_vnr(p
);
1474 read_unlock(&tasklist_lock
);
1477 retval
= wo
->wo_rusage
1478 ? getrusage(p
, RUSAGE_BOTH
, wo
->wo_rusage
) : 0;
1480 if (!retval
&& wo
->wo_stat
)
1481 retval
= put_user(0xffff, wo
->wo_stat
);
1485 retval
= wait_noreap_copyout(wo
, p
, pid
, uid
,
1486 CLD_CONTINUED
, SIGCONT
);
1487 BUG_ON(retval
== 0);
1494 * Consider @p for a wait by @parent.
1496 * -ECHILD should be in ->notask_error before the first call.
1497 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1498 * Returns zero if the search for a child should continue;
1499 * then ->notask_error is 0 if @p is an eligible child,
1500 * or another error from security_task_wait(), or still -ECHILD.
1502 static int wait_consider_task(struct wait_opts
*wo
, int ptrace
,
1503 struct task_struct
*p
)
1505 int ret
= eligible_child(wo
, p
);
1509 ret
= security_task_wait(p
);
1510 if (unlikely(ret
< 0)) {
1512 * If we have not yet seen any eligible child,
1513 * then let this error code replace -ECHILD.
1514 * A permission error will give the user a clue
1515 * to look for security policy problems, rather
1516 * than for mysterious wait bugs.
1518 if (wo
->notask_error
)
1519 wo
->notask_error
= ret
;
1523 if (likely(!ptrace
) && unlikely(task_ptrace(p
))) {
1525 * This child is hidden by ptrace.
1526 * We aren't allowed to see it now, but eventually we will.
1528 wo
->notask_error
= 0;
1532 if (p
->exit_state
== EXIT_DEAD
)
1536 * We don't reap group leaders with subthreads.
1538 if (p
->exit_state
== EXIT_ZOMBIE
&& !delay_group_leader(p
))
1539 return wait_task_zombie(wo
, p
);
1542 * It's stopped or running now, so it might
1543 * later continue, exit, or stop again.
1545 wo
->notask_error
= 0;
1547 if (task_stopped_code(p
, ptrace
))
1548 return wait_task_stopped(wo
, ptrace
, p
);
1550 return wait_task_continued(wo
, p
);
1554 * Do the work of do_wait() for one thread in the group, @tsk.
1556 * -ECHILD should be in ->notask_error before the first call.
1557 * Returns nonzero for a final return, when we have unlocked tasklist_lock.
1558 * Returns zero if the search for a child should continue; then
1559 * ->notask_error is 0 if there were any eligible children,
1560 * or another error from security_task_wait(), or still -ECHILD.
1562 static int do_wait_thread(struct wait_opts
*wo
, struct task_struct
*tsk
)
1564 struct task_struct
*p
;
1566 list_for_each_entry(p
, &tsk
->children
, sibling
) {
1567 int ret
= wait_consider_task(wo
, 0, p
);
1575 static int ptrace_do_wait(struct wait_opts
*wo
, struct task_struct
*tsk
)
1577 struct task_struct
*p
;
1579 list_for_each_entry(p
, &tsk
->ptraced
, ptrace_entry
) {
1580 int ret
= wait_consider_task(wo
, 1, p
);
1588 static int child_wait_callback(wait_queue_t
*wait
, unsigned mode
,
1589 int sync
, void *key
)
1591 struct wait_opts
*wo
= container_of(wait
, struct wait_opts
,
1593 struct task_struct
*p
= key
;
1595 if (!eligible_pid(wo
, p
))
1598 if ((wo
->wo_flags
& __WNOTHREAD
) && wait
->private != p
->parent
)
1601 return default_wake_function(wait
, mode
, sync
, key
);
1604 void __wake_up_parent(struct task_struct
*p
, struct task_struct
*parent
)
1606 __wake_up_sync_key(&parent
->signal
->wait_chldexit
,
1607 TASK_INTERRUPTIBLE
, 1, p
);
1610 static long do_wait(struct wait_opts
*wo
)
1612 struct task_struct
*tsk
;
1615 trace_sched_process_wait(wo
->wo_pid
);
1617 init_waitqueue_func_entry(&wo
->child_wait
, child_wait_callback
);
1618 wo
->child_wait
.private = current
;
1619 add_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1622 * If there is nothing that can match our critiera just get out.
1623 * We will clear ->notask_error to zero if we see any child that
1624 * might later match our criteria, even if we are not able to reap
1627 wo
->notask_error
= -ECHILD
;
1628 if ((wo
->wo_type
< PIDTYPE_MAX
) &&
1629 (!wo
->wo_pid
|| hlist_empty(&wo
->wo_pid
->tasks
[wo
->wo_type
])))
1632 set_current_state(TASK_INTERRUPTIBLE
);
1633 read_lock(&tasklist_lock
);
1636 retval
= do_wait_thread(wo
, tsk
);
1640 retval
= ptrace_do_wait(wo
, tsk
);
1644 if (wo
->wo_flags
& __WNOTHREAD
)
1646 } while_each_thread(current
, tsk
);
1647 read_unlock(&tasklist_lock
);
1650 retval
= wo
->notask_error
;
1651 if (!retval
&& !(wo
->wo_flags
& WNOHANG
)) {
1652 retval
= -ERESTARTSYS
;
1653 if (!signal_pending(current
)) {
1659 __set_current_state(TASK_RUNNING
);
1660 remove_wait_queue(¤t
->signal
->wait_chldexit
, &wo
->child_wait
);
1664 SYSCALL_DEFINE5(waitid
, int, which
, pid_t
, upid
, struct siginfo __user
*,
1665 infop
, int, options
, struct rusage __user
*, ru
)
1667 struct wait_opts wo
;
1668 struct pid
*pid
= NULL
;
1672 if (options
& ~(WNOHANG
|WNOWAIT
|WEXITED
|WSTOPPED
|WCONTINUED
))
1674 if (!(options
& (WEXITED
|WSTOPPED
|WCONTINUED
)))
1687 type
= PIDTYPE_PGID
;
1695 if (type
< PIDTYPE_MAX
)
1696 pid
= find_get_pid(upid
);
1700 wo
.wo_flags
= options
;
1710 * For a WNOHANG return, clear out all the fields
1711 * we would set so the user can easily tell the
1715 ret
= put_user(0, &infop
->si_signo
);
1717 ret
= put_user(0, &infop
->si_errno
);
1719 ret
= put_user(0, &infop
->si_code
);
1721 ret
= put_user(0, &infop
->si_pid
);
1723 ret
= put_user(0, &infop
->si_uid
);
1725 ret
= put_user(0, &infop
->si_status
);
1730 /* avoid REGPARM breakage on x86: */
1731 asmlinkage_protect(5, ret
, which
, upid
, infop
, options
, ru
);
1735 SYSCALL_DEFINE4(wait4
, pid_t
, upid
, int __user
*, stat_addr
,
1736 int, options
, struct rusage __user
*, ru
)
1738 struct wait_opts wo
;
1739 struct pid
*pid
= NULL
;
1743 if (options
& ~(WNOHANG
|WUNTRACED
|WCONTINUED
|
1744 __WNOTHREAD
|__WCLONE
|__WALL
))
1749 else if (upid
< 0) {
1750 type
= PIDTYPE_PGID
;
1751 pid
= find_get_pid(-upid
);
1752 } else if (upid
== 0) {
1753 type
= PIDTYPE_PGID
;
1754 pid
= get_task_pid(current
, PIDTYPE_PGID
);
1755 } else /* upid > 0 */ {
1757 pid
= find_get_pid(upid
);
1762 wo
.wo_flags
= options
| WEXITED
;
1764 wo
.wo_stat
= stat_addr
;
1769 /* avoid REGPARM breakage on x86: */
1770 asmlinkage_protect(4, ret
, upid
, stat_addr
, options
, ru
);
1774 #ifdef __ARCH_WANT_SYS_WAITPID
1777 * sys_waitpid() remains for compatibility. waitpid() should be
1778 * implemented by calling sys_wait4() from libc.a.
1780 SYSCALL_DEFINE3(waitpid
, pid_t
, pid
, int __user
*, stat_addr
, int, options
)
1782 return sys_wait4(pid
, stat_addr
, options
, NULL
);
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