[PATCH] vesafb: Prefer VGA registers over PMI
[linux-2.6/mini2440.git] / kernel / exit.c
blob304ef637be6c700e7b5d73172222a0e05e5f96d8
1 /*
2 * linux/kernel/exit.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
7 #include <linux/config.h>
8 #include <linux/mm.h>
9 #include <linux/slab.h>
10 #include <linux/interrupt.h>
11 #include <linux/smp_lock.h>
12 #include <linux/module.h>
13 #include <linux/capability.h>
14 #include <linux/completion.h>
15 #include <linux/personality.h>
16 #include <linux/tty.h>
17 #include <linux/namespace.h>
18 #include <linux/key.h>
19 #include <linux/security.h>
20 #include <linux/cpu.h>
21 #include <linux/acct.h>
22 #include <linux/file.h>
23 #include <linux/binfmts.h>
24 #include <linux/ptrace.h>
25 #include <linux/profile.h>
26 #include <linux/mount.h>
27 #include <linux/proc_fs.h>
28 #include <linux/mempolicy.h>
29 #include <linux/cpuset.h>
30 #include <linux/syscalls.h>
31 #include <linux/signal.h>
32 #include <linux/posix-timers.h>
33 #include <linux/cn_proc.h>
34 #include <linux/mutex.h>
35 #include <linux/futex.h>
36 #include <linux/compat.h>
37 #include <linux/pipe_fs_i.h>
38 #include <linux/audit.h> /* for audit_free() */
39 #include <linux/resource.h>
41 #include <asm/uaccess.h>
42 #include <asm/unistd.h>
43 #include <asm/pgtable.h>
44 #include <asm/mmu_context.h>
46 extern void sem_exit (void);
47 extern struct task_struct *child_reaper;
49 static void exit_mm(struct task_struct * tsk);
51 static void __unhash_process(struct task_struct *p)
53 nr_threads--;
54 detach_pid(p, PIDTYPE_PID);
55 if (thread_group_leader(p)) {
56 detach_pid(p, PIDTYPE_PGID);
57 detach_pid(p, PIDTYPE_SID);
59 list_del_rcu(&p->tasks);
60 __get_cpu_var(process_counts)--;
62 list_del_rcu(&p->thread_group);
63 remove_parent(p);
67 * This function expects the tasklist_lock write-locked.
69 static void __exit_signal(struct task_struct *tsk)
71 struct signal_struct *sig = tsk->signal;
72 struct sighand_struct *sighand;
74 BUG_ON(!sig);
75 BUG_ON(!atomic_read(&sig->count));
77 rcu_read_lock();
78 sighand = rcu_dereference(tsk->sighand);
79 spin_lock(&sighand->siglock);
81 posix_cpu_timers_exit(tsk);
82 if (atomic_dec_and_test(&sig->count))
83 posix_cpu_timers_exit_group(tsk);
84 else {
86 * If there is any task waiting for the group exit
87 * then notify it:
89 if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) {
90 wake_up_process(sig->group_exit_task);
91 sig->group_exit_task = NULL;
93 if (tsk == sig->curr_target)
94 sig->curr_target = next_thread(tsk);
96 * Accumulate here the counters for all threads but the
97 * group leader as they die, so they can be added into
98 * the process-wide totals when those are taken.
99 * The group leader stays around as a zombie as long
100 * as there are other threads. When it gets reaped,
101 * the exit.c code will add its counts into these totals.
102 * We won't ever get here for the group leader, since it
103 * will have been the last reference on the signal_struct.
105 sig->utime = cputime_add(sig->utime, tsk->utime);
106 sig->stime = cputime_add(sig->stime, tsk->stime);
107 sig->min_flt += tsk->min_flt;
108 sig->maj_flt += tsk->maj_flt;
109 sig->nvcsw += tsk->nvcsw;
110 sig->nivcsw += tsk->nivcsw;
111 sig->sched_time += tsk->sched_time;
112 sig = NULL; /* Marker for below. */
115 __unhash_process(tsk);
117 tsk->signal = NULL;
118 tsk->sighand = NULL;
119 spin_unlock(&sighand->siglock);
120 rcu_read_unlock();
122 __cleanup_sighand(sighand);
123 clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
124 flush_sigqueue(&tsk->pending);
125 if (sig) {
126 flush_sigqueue(&sig->shared_pending);
127 __cleanup_signal(sig);
131 static void delayed_put_task_struct(struct rcu_head *rhp)
133 put_task_struct(container_of(rhp, struct task_struct, rcu));
136 void release_task(struct task_struct * p)
138 int zap_leader;
139 task_t *leader;
140 repeat:
141 atomic_dec(&p->user->processes);
142 write_lock_irq(&tasklist_lock);
143 ptrace_unlink(p);
144 BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
145 __exit_signal(p);
148 * If we are the last non-leader member of the thread
149 * group, and the leader is zombie, then notify the
150 * group leader's parent process. (if it wants notification.)
152 zap_leader = 0;
153 leader = p->group_leader;
154 if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
155 BUG_ON(leader->exit_signal == -1);
156 do_notify_parent(leader, leader->exit_signal);
158 * If we were the last child thread and the leader has
159 * exited already, and the leader's parent ignores SIGCHLD,
160 * then we are the one who should release the leader.
162 * do_notify_parent() will have marked it self-reaping in
163 * that case.
165 zap_leader = (leader->exit_signal == -1);
168 sched_exit(p);
169 write_unlock_irq(&tasklist_lock);
170 proc_flush_task(p);
171 release_thread(p);
172 call_rcu(&p->rcu, delayed_put_task_struct);
174 p = leader;
175 if (unlikely(zap_leader))
176 goto repeat;
180 * This checks not only the pgrp, but falls back on the pid if no
181 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
182 * without this...
184 int session_of_pgrp(int pgrp)
186 struct task_struct *p;
187 int sid = -1;
189 read_lock(&tasklist_lock);
190 do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
191 if (p->signal->session > 0) {
192 sid = p->signal->session;
193 goto out;
195 } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
196 p = find_task_by_pid(pgrp);
197 if (p)
198 sid = p->signal->session;
199 out:
200 read_unlock(&tasklist_lock);
202 return sid;
206 * Determine if a process group is "orphaned", according to the POSIX
207 * definition in 2.2.2.52. Orphaned process groups are not to be affected
208 * by terminal-generated stop signals. Newly orphaned process groups are
209 * to receive a SIGHUP and a SIGCONT.
211 * "I ask you, have you ever known what it is to be an orphan?"
213 static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task)
215 struct task_struct *p;
216 int ret = 1;
218 do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
219 if (p == ignored_task
220 || p->exit_state
221 || p->real_parent->pid == 1)
222 continue;
223 if (process_group(p->real_parent) != pgrp
224 && p->real_parent->signal->session == p->signal->session) {
225 ret = 0;
226 break;
228 } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
229 return ret; /* (sighing) "Often!" */
232 int is_orphaned_pgrp(int pgrp)
234 int retval;
236 read_lock(&tasklist_lock);
237 retval = will_become_orphaned_pgrp(pgrp, NULL);
238 read_unlock(&tasklist_lock);
240 return retval;
243 static int has_stopped_jobs(int pgrp)
245 int retval = 0;
246 struct task_struct *p;
248 do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
249 if (p->state != TASK_STOPPED)
250 continue;
252 /* If p is stopped by a debugger on a signal that won't
253 stop it, then don't count p as stopped. This isn't
254 perfect but it's a good approximation. */
255 if (unlikely (p->ptrace)
256 && p->exit_code != SIGSTOP
257 && p->exit_code != SIGTSTP
258 && p->exit_code != SIGTTOU
259 && p->exit_code != SIGTTIN)
260 continue;
262 retval = 1;
263 break;
264 } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
265 return retval;
269 * reparent_to_init - Reparent the calling kernel thread to the init task.
271 * If a kernel thread is launched as a result of a system call, or if
272 * it ever exits, it should generally reparent itself to init so that
273 * it is correctly cleaned up on exit.
275 * The various task state such as scheduling policy and priority may have
276 * been inherited from a user process, so we reset them to sane values here.
278 * NOTE that reparent_to_init() gives the caller full capabilities.
280 static void reparent_to_init(void)
282 write_lock_irq(&tasklist_lock);
284 ptrace_unlink(current);
285 /* Reparent to init */
286 remove_parent(current);
287 current->parent = child_reaper;
288 current->real_parent = child_reaper;
289 add_parent(current);
291 /* Set the exit signal to SIGCHLD so we signal init on exit */
292 current->exit_signal = SIGCHLD;
294 if ((current->policy == SCHED_NORMAL ||
295 current->policy == SCHED_BATCH)
296 && (task_nice(current) < 0))
297 set_user_nice(current, 0);
298 /* cpus_allowed? */
299 /* rt_priority? */
300 /* signals? */
301 security_task_reparent_to_init(current);
302 memcpy(current->signal->rlim, init_task.signal->rlim,
303 sizeof(current->signal->rlim));
304 atomic_inc(&(INIT_USER->__count));
305 write_unlock_irq(&tasklist_lock);
306 switch_uid(INIT_USER);
309 void __set_special_pids(pid_t session, pid_t pgrp)
311 struct task_struct *curr = current->group_leader;
313 if (curr->signal->session != session) {
314 detach_pid(curr, PIDTYPE_SID);
315 curr->signal->session = session;
316 attach_pid(curr, PIDTYPE_SID, session);
318 if (process_group(curr) != pgrp) {
319 detach_pid(curr, PIDTYPE_PGID);
320 curr->signal->pgrp = pgrp;
321 attach_pid(curr, PIDTYPE_PGID, pgrp);
325 void set_special_pids(pid_t session, pid_t pgrp)
327 write_lock_irq(&tasklist_lock);
328 __set_special_pids(session, pgrp);
329 write_unlock_irq(&tasklist_lock);
333 * Let kernel threads use this to say that they
334 * allow a certain signal (since daemonize() will
335 * have disabled all of them by default).
337 int allow_signal(int sig)
339 if (!valid_signal(sig) || sig < 1)
340 return -EINVAL;
342 spin_lock_irq(&current->sighand->siglock);
343 sigdelset(&current->blocked, sig);
344 if (!current->mm) {
345 /* Kernel threads handle their own signals.
346 Let the signal code know it'll be handled, so
347 that they don't get converted to SIGKILL or
348 just silently dropped */
349 current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
351 recalc_sigpending();
352 spin_unlock_irq(&current->sighand->siglock);
353 return 0;
356 EXPORT_SYMBOL(allow_signal);
358 int disallow_signal(int sig)
360 if (!valid_signal(sig) || sig < 1)
361 return -EINVAL;
363 spin_lock_irq(&current->sighand->siglock);
364 sigaddset(&current->blocked, sig);
365 recalc_sigpending();
366 spin_unlock_irq(&current->sighand->siglock);
367 return 0;
370 EXPORT_SYMBOL(disallow_signal);
373 * Put all the gunge required to become a kernel thread without
374 * attached user resources in one place where it belongs.
377 void daemonize(const char *name, ...)
379 va_list args;
380 struct fs_struct *fs;
381 sigset_t blocked;
383 va_start(args, name);
384 vsnprintf(current->comm, sizeof(current->comm), name, args);
385 va_end(args);
388 * If we were started as result of loading a module, close all of the
389 * user space pages. We don't need them, and if we didn't close them
390 * they would be locked into memory.
392 exit_mm(current);
394 set_special_pids(1, 1);
395 mutex_lock(&tty_mutex);
396 current->signal->tty = NULL;
397 mutex_unlock(&tty_mutex);
399 /* Block and flush all signals */
400 sigfillset(&blocked);
401 sigprocmask(SIG_BLOCK, &blocked, NULL);
402 flush_signals(current);
404 /* Become as one with the init task */
406 exit_fs(current); /* current->fs->count--; */
407 fs = init_task.fs;
408 current->fs = fs;
409 atomic_inc(&fs->count);
410 exit_namespace(current);
411 current->namespace = init_task.namespace;
412 get_namespace(current->namespace);
413 exit_files(current);
414 current->files = init_task.files;
415 atomic_inc(&current->files->count);
417 reparent_to_init();
420 EXPORT_SYMBOL(daemonize);
422 static void close_files(struct files_struct * files)
424 int i, j;
425 struct fdtable *fdt;
427 j = 0;
430 * It is safe to dereference the fd table without RCU or
431 * ->file_lock because this is the last reference to the
432 * files structure.
434 fdt = files_fdtable(files);
435 for (;;) {
436 unsigned long set;
437 i = j * __NFDBITS;
438 if (i >= fdt->max_fdset || i >= fdt->max_fds)
439 break;
440 set = fdt->open_fds->fds_bits[j++];
441 while (set) {
442 if (set & 1) {
443 struct file * file = xchg(&fdt->fd[i], NULL);
444 if (file)
445 filp_close(file, files);
447 i++;
448 set >>= 1;
453 struct files_struct *get_files_struct(struct task_struct *task)
455 struct files_struct *files;
457 task_lock(task);
458 files = task->files;
459 if (files)
460 atomic_inc(&files->count);
461 task_unlock(task);
463 return files;
466 void fastcall put_files_struct(struct files_struct *files)
468 struct fdtable *fdt;
470 if (atomic_dec_and_test(&files->count)) {
471 close_files(files);
473 * Free the fd and fdset arrays if we expanded them.
474 * If the fdtable was embedded, pass files for freeing
475 * at the end of the RCU grace period. Otherwise,
476 * you can free files immediately.
478 fdt = files_fdtable(files);
479 if (fdt == &files->fdtab)
480 fdt->free_files = files;
481 else
482 kmem_cache_free(files_cachep, files);
483 free_fdtable(fdt);
487 EXPORT_SYMBOL(put_files_struct);
489 static inline void __exit_files(struct task_struct *tsk)
491 struct files_struct * files = tsk->files;
493 if (files) {
494 task_lock(tsk);
495 tsk->files = NULL;
496 task_unlock(tsk);
497 put_files_struct(files);
501 void exit_files(struct task_struct *tsk)
503 __exit_files(tsk);
506 static inline void __put_fs_struct(struct fs_struct *fs)
508 /* No need to hold fs->lock if we are killing it */
509 if (atomic_dec_and_test(&fs->count)) {
510 dput(fs->root);
511 mntput(fs->rootmnt);
512 dput(fs->pwd);
513 mntput(fs->pwdmnt);
514 if (fs->altroot) {
515 dput(fs->altroot);
516 mntput(fs->altrootmnt);
518 kmem_cache_free(fs_cachep, fs);
522 void put_fs_struct(struct fs_struct *fs)
524 __put_fs_struct(fs);
527 static inline void __exit_fs(struct task_struct *tsk)
529 struct fs_struct * fs = tsk->fs;
531 if (fs) {
532 task_lock(tsk);
533 tsk->fs = NULL;
534 task_unlock(tsk);
535 __put_fs_struct(fs);
539 void exit_fs(struct task_struct *tsk)
541 __exit_fs(tsk);
544 EXPORT_SYMBOL_GPL(exit_fs);
547 * Turn us into a lazy TLB process if we
548 * aren't already..
550 static void exit_mm(struct task_struct * tsk)
552 struct mm_struct *mm = tsk->mm;
554 mm_release(tsk, mm);
555 if (!mm)
556 return;
558 * Serialize with any possible pending coredump.
559 * We must hold mmap_sem around checking core_waiters
560 * and clearing tsk->mm. The core-inducing thread
561 * will increment core_waiters for each thread in the
562 * group with ->mm != NULL.
564 down_read(&mm->mmap_sem);
565 if (mm->core_waiters) {
566 up_read(&mm->mmap_sem);
567 down_write(&mm->mmap_sem);
568 if (!--mm->core_waiters)
569 complete(mm->core_startup_done);
570 up_write(&mm->mmap_sem);
572 wait_for_completion(&mm->core_done);
573 down_read(&mm->mmap_sem);
575 atomic_inc(&mm->mm_count);
576 BUG_ON(mm != tsk->active_mm);
577 /* more a memory barrier than a real lock */
578 task_lock(tsk);
579 tsk->mm = NULL;
580 up_read(&mm->mmap_sem);
581 enter_lazy_tlb(mm, current);
582 task_unlock(tsk);
583 mmput(mm);
586 static inline void choose_new_parent(task_t *p, task_t *reaper)
589 * Make sure we're not reparenting to ourselves and that
590 * the parent is not a zombie.
592 BUG_ON(p == reaper || reaper->exit_state);
593 p->real_parent = reaper;
596 static void reparent_thread(task_t *p, task_t *father, int traced)
598 /* We don't want people slaying init. */
599 if (p->exit_signal != -1)
600 p->exit_signal = SIGCHLD;
602 if (p->pdeath_signal)
603 /* We already hold the tasklist_lock here. */
604 group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
606 /* Move the child from its dying parent to the new one. */
607 if (unlikely(traced)) {
608 /* Preserve ptrace links if someone else is tracing this child. */
609 list_del_init(&p->ptrace_list);
610 if (p->parent != p->real_parent)
611 list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
612 } else {
613 /* If this child is being traced, then we're the one tracing it
614 * anyway, so let go of it.
616 p->ptrace = 0;
617 remove_parent(p);
618 p->parent = p->real_parent;
619 add_parent(p);
621 /* If we'd notified the old parent about this child's death,
622 * also notify the new parent.
624 if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
625 thread_group_empty(p))
626 do_notify_parent(p, p->exit_signal);
627 else if (p->state == TASK_TRACED) {
629 * If it was at a trace stop, turn it into
630 * a normal stop since it's no longer being
631 * traced.
633 ptrace_untrace(p);
638 * process group orphan check
639 * Case ii: Our child is in a different pgrp
640 * than we are, and it was the only connection
641 * outside, so the child pgrp is now orphaned.
643 if ((process_group(p) != process_group(father)) &&
644 (p->signal->session == father->signal->session)) {
645 int pgrp = process_group(p);
647 if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
648 __kill_pg_info(SIGHUP, SEND_SIG_PRIV, pgrp);
649 __kill_pg_info(SIGCONT, SEND_SIG_PRIV, pgrp);
655 * When we die, we re-parent all our children.
656 * Try to give them to another thread in our thread
657 * group, and if no such member exists, give it to
658 * the global child reaper process (ie "init")
660 static void forget_original_parent(struct task_struct * father,
661 struct list_head *to_release)
663 struct task_struct *p, *reaper = father;
664 struct list_head *_p, *_n;
666 do {
667 reaper = next_thread(reaper);
668 if (reaper == father) {
669 reaper = child_reaper;
670 break;
672 } while (reaper->exit_state);
675 * There are only two places where our children can be:
677 * - in our child list
678 * - in our ptraced child list
680 * Search them and reparent children.
682 list_for_each_safe(_p, _n, &father->children) {
683 int ptrace;
684 p = list_entry(_p,struct task_struct,sibling);
686 ptrace = p->ptrace;
688 /* if father isn't the real parent, then ptrace must be enabled */
689 BUG_ON(father != p->real_parent && !ptrace);
691 if (father == p->real_parent) {
692 /* reparent with a reaper, real father it's us */
693 choose_new_parent(p, reaper);
694 reparent_thread(p, father, 0);
695 } else {
696 /* reparent ptraced task to its real parent */
697 __ptrace_unlink (p);
698 if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
699 thread_group_empty(p))
700 do_notify_parent(p, p->exit_signal);
704 * if the ptraced child is a zombie with exit_signal == -1
705 * we must collect it before we exit, or it will remain
706 * zombie forever since we prevented it from self-reap itself
707 * while it was being traced by us, to be able to see it in wait4.
709 if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1))
710 list_add(&p->ptrace_list, to_release);
712 list_for_each_safe(_p, _n, &father->ptrace_children) {
713 p = list_entry(_p,struct task_struct,ptrace_list);
714 choose_new_parent(p, reaper);
715 reparent_thread(p, father, 1);
720 * Send signals to all our closest relatives so that they know
721 * to properly mourn us..
723 static void exit_notify(struct task_struct *tsk)
725 int state;
726 struct task_struct *t;
727 struct list_head ptrace_dead, *_p, *_n;
729 if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT)
730 && !thread_group_empty(tsk)) {
732 * This occurs when there was a race between our exit
733 * syscall and a group signal choosing us as the one to
734 * wake up. It could be that we are the only thread
735 * alerted to check for pending signals, but another thread
736 * should be woken now to take the signal since we will not.
737 * Now we'll wake all the threads in the group just to make
738 * sure someone gets all the pending signals.
740 read_lock(&tasklist_lock);
741 spin_lock_irq(&tsk->sighand->siglock);
742 for (t = next_thread(tsk); t != tsk; t = next_thread(t))
743 if (!signal_pending(t) && !(t->flags & PF_EXITING)) {
744 recalc_sigpending_tsk(t);
745 if (signal_pending(t))
746 signal_wake_up(t, 0);
748 spin_unlock_irq(&tsk->sighand->siglock);
749 read_unlock(&tasklist_lock);
752 write_lock_irq(&tasklist_lock);
755 * This does two things:
757 * A. Make init inherit all the child processes
758 * B. Check to see if any process groups have become orphaned
759 * as a result of our exiting, and if they have any stopped
760 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
763 INIT_LIST_HEAD(&ptrace_dead);
764 forget_original_parent(tsk, &ptrace_dead);
765 BUG_ON(!list_empty(&tsk->children));
766 BUG_ON(!list_empty(&tsk->ptrace_children));
769 * Check to see if any process groups have become orphaned
770 * as a result of our exiting, and if they have any stopped
771 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
773 * Case i: Our father is in a different pgrp than we are
774 * and we were the only connection outside, so our pgrp
775 * is about to become orphaned.
778 t = tsk->real_parent;
780 if ((process_group(t) != process_group(tsk)) &&
781 (t->signal->session == tsk->signal->session) &&
782 will_become_orphaned_pgrp(process_group(tsk), tsk) &&
783 has_stopped_jobs(process_group(tsk))) {
784 __kill_pg_info(SIGHUP, SEND_SIG_PRIV, process_group(tsk));
785 __kill_pg_info(SIGCONT, SEND_SIG_PRIV, process_group(tsk));
788 /* Let father know we died
790 * Thread signals are configurable, but you aren't going to use
791 * that to send signals to arbitary processes.
792 * That stops right now.
794 * If the parent exec id doesn't match the exec id we saved
795 * when we started then we know the parent has changed security
796 * domain.
798 * If our self_exec id doesn't match our parent_exec_id then
799 * we have changed execution domain as these two values started
800 * the same after a fork.
804 if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
805 ( tsk->parent_exec_id != t->self_exec_id ||
806 tsk->self_exec_id != tsk->parent_exec_id)
807 && !capable(CAP_KILL))
808 tsk->exit_signal = SIGCHLD;
811 /* If something other than our normal parent is ptracing us, then
812 * send it a SIGCHLD instead of honoring exit_signal. exit_signal
813 * only has special meaning to our real parent.
815 if (tsk->exit_signal != -1 && thread_group_empty(tsk)) {
816 int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD;
817 do_notify_parent(tsk, signal);
818 } else if (tsk->ptrace) {
819 do_notify_parent(tsk, SIGCHLD);
822 state = EXIT_ZOMBIE;
823 if (tsk->exit_signal == -1 &&
824 (likely(tsk->ptrace == 0) ||
825 unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT)))
826 state = EXIT_DEAD;
827 tsk->exit_state = state;
829 write_unlock_irq(&tasklist_lock);
831 list_for_each_safe(_p, _n, &ptrace_dead) {
832 list_del_init(_p);
833 t = list_entry(_p,struct task_struct,ptrace_list);
834 release_task(t);
837 /* If the process is dead, release it - nobody will wait for it */
838 if (state == EXIT_DEAD)
839 release_task(tsk);
842 fastcall NORET_TYPE void do_exit(long code)
844 struct task_struct *tsk = current;
845 int group_dead;
847 profile_task_exit(tsk);
849 WARN_ON(atomic_read(&tsk->fs_excl));
851 if (unlikely(in_interrupt()))
852 panic("Aiee, killing interrupt handler!");
853 if (unlikely(!tsk->pid))
854 panic("Attempted to kill the idle task!");
855 if (unlikely(tsk == child_reaper))
856 panic("Attempted to kill init!");
858 if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
859 current->ptrace_message = code;
860 ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
864 * We're taking recursive faults here in do_exit. Safest is to just
865 * leave this task alone and wait for reboot.
867 if (unlikely(tsk->flags & PF_EXITING)) {
868 printk(KERN_ALERT
869 "Fixing recursive fault but reboot is needed!\n");
870 if (tsk->io_context)
871 exit_io_context();
872 set_current_state(TASK_UNINTERRUPTIBLE);
873 schedule();
876 tsk->flags |= PF_EXITING;
878 if (unlikely(in_atomic()))
879 printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
880 current->comm, current->pid,
881 preempt_count());
883 acct_update_integrals(tsk);
884 if (tsk->mm) {
885 update_hiwater_rss(tsk->mm);
886 update_hiwater_vm(tsk->mm);
888 group_dead = atomic_dec_and_test(&tsk->signal->live);
889 if (group_dead) {
890 hrtimer_cancel(&tsk->signal->real_timer);
891 exit_itimers(tsk->signal);
893 acct_collect(code, group_dead);
894 if (unlikely(tsk->robust_list))
895 exit_robust_list(tsk);
896 #if defined(CONFIG_FUTEX) && defined(CONFIG_COMPAT)
897 if (unlikely(tsk->compat_robust_list))
898 compat_exit_robust_list(tsk);
899 #endif
900 if (unlikely(tsk->audit_context))
901 audit_free(tsk);
902 exit_mm(tsk);
904 if (group_dead)
905 acct_process();
906 exit_sem(tsk);
907 __exit_files(tsk);
908 __exit_fs(tsk);
909 exit_namespace(tsk);
910 exit_thread();
911 cpuset_exit(tsk);
912 exit_keys(tsk);
914 if (group_dead && tsk->signal->leader)
915 disassociate_ctty(1);
917 module_put(task_thread_info(tsk)->exec_domain->module);
918 if (tsk->binfmt)
919 module_put(tsk->binfmt->module);
921 tsk->exit_code = code;
922 proc_exit_connector(tsk);
923 exit_notify(tsk);
924 #ifdef CONFIG_NUMA
925 mpol_free(tsk->mempolicy);
926 tsk->mempolicy = NULL;
927 #endif
929 * If DEBUG_MUTEXES is on, make sure we are holding no locks:
931 mutex_debug_check_no_locks_held(tsk);
933 if (tsk->io_context)
934 exit_io_context();
936 if (tsk->splice_pipe)
937 __free_pipe_info(tsk->splice_pipe);
939 /* PF_DEAD causes final put_task_struct after we schedule. */
940 preempt_disable();
941 BUG_ON(tsk->flags & PF_DEAD);
942 tsk->flags |= PF_DEAD;
944 schedule();
945 BUG();
946 /* Avoid "noreturn function does return". */
947 for (;;) ;
950 EXPORT_SYMBOL_GPL(do_exit);
952 NORET_TYPE void complete_and_exit(struct completion *comp, long code)
954 if (comp)
955 complete(comp);
957 do_exit(code);
960 EXPORT_SYMBOL(complete_and_exit);
962 asmlinkage long sys_exit(int error_code)
964 do_exit((error_code&0xff)<<8);
968 * Take down every thread in the group. This is called by fatal signals
969 * as well as by sys_exit_group (below).
971 NORET_TYPE void
972 do_group_exit(int exit_code)
974 BUG_ON(exit_code & 0x80); /* core dumps don't get here */
976 if (current->signal->flags & SIGNAL_GROUP_EXIT)
977 exit_code = current->signal->group_exit_code;
978 else if (!thread_group_empty(current)) {
979 struct signal_struct *const sig = current->signal;
980 struct sighand_struct *const sighand = current->sighand;
981 spin_lock_irq(&sighand->siglock);
982 if (sig->flags & SIGNAL_GROUP_EXIT)
983 /* Another thread got here before we took the lock. */
984 exit_code = sig->group_exit_code;
985 else {
986 sig->group_exit_code = exit_code;
987 zap_other_threads(current);
989 spin_unlock_irq(&sighand->siglock);
992 do_exit(exit_code);
993 /* NOTREACHED */
997 * this kills every thread in the thread group. Note that any externally
998 * wait4()-ing process will get the correct exit code - even if this
999 * thread is not the thread group leader.
1001 asmlinkage void sys_exit_group(int error_code)
1003 do_group_exit((error_code & 0xff) << 8);
1006 static int eligible_child(pid_t pid, int options, task_t *p)
1008 if (pid > 0) {
1009 if (p->pid != pid)
1010 return 0;
1011 } else if (!pid) {
1012 if (process_group(p) != process_group(current))
1013 return 0;
1014 } else if (pid != -1) {
1015 if (process_group(p) != -pid)
1016 return 0;
1020 * Do not consider detached threads that are
1021 * not ptraced:
1023 if (p->exit_signal == -1 && !p->ptrace)
1024 return 0;
1026 /* Wait for all children (clone and not) if __WALL is set;
1027 * otherwise, wait for clone children *only* if __WCLONE is
1028 * set; otherwise, wait for non-clone children *only*. (Note:
1029 * A "clone" child here is one that reports to its parent
1030 * using a signal other than SIGCHLD.) */
1031 if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
1032 && !(options & __WALL))
1033 return 0;
1035 * Do not consider thread group leaders that are
1036 * in a non-empty thread group:
1038 if (current->tgid != p->tgid && delay_group_leader(p))
1039 return 2;
1041 if (security_task_wait(p))
1042 return 0;
1044 return 1;
1047 static int wait_noreap_copyout(task_t *p, pid_t pid, uid_t uid,
1048 int why, int status,
1049 struct siginfo __user *infop,
1050 struct rusage __user *rusagep)
1052 int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0;
1053 put_task_struct(p);
1054 if (!retval)
1055 retval = put_user(SIGCHLD, &infop->si_signo);
1056 if (!retval)
1057 retval = put_user(0, &infop->si_errno);
1058 if (!retval)
1059 retval = put_user((short)why, &infop->si_code);
1060 if (!retval)
1061 retval = put_user(pid, &infop->si_pid);
1062 if (!retval)
1063 retval = put_user(uid, &infop->si_uid);
1064 if (!retval)
1065 retval = put_user(status, &infop->si_status);
1066 if (!retval)
1067 retval = pid;
1068 return retval;
1072 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
1073 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1074 * the lock and this task is uninteresting. If we return nonzero, we have
1075 * released the lock and the system call should return.
1077 static int wait_task_zombie(task_t *p, int noreap,
1078 struct siginfo __user *infop,
1079 int __user *stat_addr, struct rusage __user *ru)
1081 unsigned long state;
1082 int retval;
1083 int status;
1085 if (unlikely(noreap)) {
1086 pid_t pid = p->pid;
1087 uid_t uid = p->uid;
1088 int exit_code = p->exit_code;
1089 int why, status;
1091 if (unlikely(p->exit_state != EXIT_ZOMBIE))
1092 return 0;
1093 if (unlikely(p->exit_signal == -1 && p->ptrace == 0))
1094 return 0;
1095 get_task_struct(p);
1096 read_unlock(&tasklist_lock);
1097 if ((exit_code & 0x7f) == 0) {
1098 why = CLD_EXITED;
1099 status = exit_code >> 8;
1100 } else {
1101 why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
1102 status = exit_code & 0x7f;
1104 return wait_noreap_copyout(p, pid, uid, why,
1105 status, infop, ru);
1109 * Try to move the task's state to DEAD
1110 * only one thread is allowed to do this:
1112 state = xchg(&p->exit_state, EXIT_DEAD);
1113 if (state != EXIT_ZOMBIE) {
1114 BUG_ON(state != EXIT_DEAD);
1115 return 0;
1117 if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) {
1119 * This can only happen in a race with a ptraced thread
1120 * dying on another processor.
1122 return 0;
1125 if (likely(p->real_parent == p->parent) && likely(p->signal)) {
1126 struct signal_struct *psig;
1127 struct signal_struct *sig;
1130 * The resource counters for the group leader are in its
1131 * own task_struct. Those for dead threads in the group
1132 * are in its signal_struct, as are those for the child
1133 * processes it has previously reaped. All these
1134 * accumulate in the parent's signal_struct c* fields.
1136 * We don't bother to take a lock here to protect these
1137 * p->signal fields, because they are only touched by
1138 * __exit_signal, which runs with tasklist_lock
1139 * write-locked anyway, and so is excluded here. We do
1140 * need to protect the access to p->parent->signal fields,
1141 * as other threads in the parent group can be right
1142 * here reaping other children at the same time.
1144 spin_lock_irq(&p->parent->sighand->siglock);
1145 psig = p->parent->signal;
1146 sig = p->signal;
1147 psig->cutime =
1148 cputime_add(psig->cutime,
1149 cputime_add(p->utime,
1150 cputime_add(sig->utime,
1151 sig->cutime)));
1152 psig->cstime =
1153 cputime_add(psig->cstime,
1154 cputime_add(p->stime,
1155 cputime_add(sig->stime,
1156 sig->cstime)));
1157 psig->cmin_flt +=
1158 p->min_flt + sig->min_flt + sig->cmin_flt;
1159 psig->cmaj_flt +=
1160 p->maj_flt + sig->maj_flt + sig->cmaj_flt;
1161 psig->cnvcsw +=
1162 p->nvcsw + sig->nvcsw + sig->cnvcsw;
1163 psig->cnivcsw +=
1164 p->nivcsw + sig->nivcsw + sig->cnivcsw;
1165 spin_unlock_irq(&p->parent->sighand->siglock);
1169 * Now we are sure this task is interesting, and no other
1170 * thread can reap it because we set its state to EXIT_DEAD.
1172 read_unlock(&tasklist_lock);
1174 retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
1175 status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1176 ? p->signal->group_exit_code : p->exit_code;
1177 if (!retval && stat_addr)
1178 retval = put_user(status, stat_addr);
1179 if (!retval && infop)
1180 retval = put_user(SIGCHLD, &infop->si_signo);
1181 if (!retval && infop)
1182 retval = put_user(0, &infop->si_errno);
1183 if (!retval && infop) {
1184 int why;
1186 if ((status & 0x7f) == 0) {
1187 why = CLD_EXITED;
1188 status >>= 8;
1189 } else {
1190 why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
1191 status &= 0x7f;
1193 retval = put_user((short)why, &infop->si_code);
1194 if (!retval)
1195 retval = put_user(status, &infop->si_status);
1197 if (!retval && infop)
1198 retval = put_user(p->pid, &infop->si_pid);
1199 if (!retval && infop)
1200 retval = put_user(p->uid, &infop->si_uid);
1201 if (retval) {
1202 // TODO: is this safe?
1203 p->exit_state = EXIT_ZOMBIE;
1204 return retval;
1206 retval = p->pid;
1207 if (p->real_parent != p->parent) {
1208 write_lock_irq(&tasklist_lock);
1209 /* Double-check with lock held. */
1210 if (p->real_parent != p->parent) {
1211 __ptrace_unlink(p);
1212 // TODO: is this safe?
1213 p->exit_state = EXIT_ZOMBIE;
1215 * If this is not a detached task, notify the parent.
1216 * If it's still not detached after that, don't release
1217 * it now.
1219 if (p->exit_signal != -1) {
1220 do_notify_parent(p, p->exit_signal);
1221 if (p->exit_signal != -1)
1222 p = NULL;
1225 write_unlock_irq(&tasklist_lock);
1227 if (p != NULL)
1228 release_task(p);
1229 BUG_ON(!retval);
1230 return retval;
1234 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1235 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1236 * the lock and this task is uninteresting. If we return nonzero, we have
1237 * released the lock and the system call should return.
1239 static int wait_task_stopped(task_t *p, int delayed_group_leader, int noreap,
1240 struct siginfo __user *infop,
1241 int __user *stat_addr, struct rusage __user *ru)
1243 int retval, exit_code;
1245 if (!p->exit_code)
1246 return 0;
1247 if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
1248 p->signal && p->signal->group_stop_count > 0)
1250 * A group stop is in progress and this is the group leader.
1251 * We won't report until all threads have stopped.
1253 return 0;
1256 * Now we are pretty sure this task is interesting.
1257 * Make sure it doesn't get reaped out from under us while we
1258 * give up the lock and then examine it below. We don't want to
1259 * keep holding onto the tasklist_lock while we call getrusage and
1260 * possibly take page faults for user memory.
1262 get_task_struct(p);
1263 read_unlock(&tasklist_lock);
1265 if (unlikely(noreap)) {
1266 pid_t pid = p->pid;
1267 uid_t uid = p->uid;
1268 int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
1270 exit_code = p->exit_code;
1271 if (unlikely(!exit_code) ||
1272 unlikely(p->state & TASK_TRACED))
1273 goto bail_ref;
1274 return wait_noreap_copyout(p, pid, uid,
1275 why, (exit_code << 8) | 0x7f,
1276 infop, ru);
1279 write_lock_irq(&tasklist_lock);
1282 * This uses xchg to be atomic with the thread resuming and setting
1283 * it. It must also be done with the write lock held to prevent a
1284 * race with the EXIT_ZOMBIE case.
1286 exit_code = xchg(&p->exit_code, 0);
1287 if (unlikely(p->exit_state)) {
1289 * The task resumed and then died. Let the next iteration
1290 * catch it in EXIT_ZOMBIE. Note that exit_code might
1291 * already be zero here if it resumed and did _exit(0).
1292 * The task itself is dead and won't touch exit_code again;
1293 * other processors in this function are locked out.
1295 p->exit_code = exit_code;
1296 exit_code = 0;
1298 if (unlikely(exit_code == 0)) {
1300 * Another thread in this function got to it first, or it
1301 * resumed, or it resumed and then died.
1303 write_unlock_irq(&tasklist_lock);
1304 bail_ref:
1305 put_task_struct(p);
1307 * We are returning to the wait loop without having successfully
1308 * removed the process and having released the lock. We cannot
1309 * continue, since the "p" task pointer is potentially stale.
1311 * Return -EAGAIN, and do_wait() will restart the loop from the
1312 * beginning. Do _not_ re-acquire the lock.
1314 return -EAGAIN;
1317 /* move to end of parent's list to avoid starvation */
1318 remove_parent(p);
1319 add_parent(p);
1321 write_unlock_irq(&tasklist_lock);
1323 retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
1324 if (!retval && stat_addr)
1325 retval = put_user((exit_code << 8) | 0x7f, stat_addr);
1326 if (!retval && infop)
1327 retval = put_user(SIGCHLD, &infop->si_signo);
1328 if (!retval && infop)
1329 retval = put_user(0, &infop->si_errno);
1330 if (!retval && infop)
1331 retval = put_user((short)((p->ptrace & PT_PTRACED)
1332 ? CLD_TRAPPED : CLD_STOPPED),
1333 &infop->si_code);
1334 if (!retval && infop)
1335 retval = put_user(exit_code, &infop->si_status);
1336 if (!retval && infop)
1337 retval = put_user(p->pid, &infop->si_pid);
1338 if (!retval && infop)
1339 retval = put_user(p->uid, &infop->si_uid);
1340 if (!retval)
1341 retval = p->pid;
1342 put_task_struct(p);
1344 BUG_ON(!retval);
1345 return retval;
1349 * Handle do_wait work for one task in a live, non-stopped state.
1350 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1351 * the lock and this task is uninteresting. If we return nonzero, we have
1352 * released the lock and the system call should return.
1354 static int wait_task_continued(task_t *p, int noreap,
1355 struct siginfo __user *infop,
1356 int __user *stat_addr, struct rusage __user *ru)
1358 int retval;
1359 pid_t pid;
1360 uid_t uid;
1362 if (unlikely(!p->signal))
1363 return 0;
1365 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
1366 return 0;
1368 spin_lock_irq(&p->sighand->siglock);
1369 /* Re-check with the lock held. */
1370 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
1371 spin_unlock_irq(&p->sighand->siglock);
1372 return 0;
1374 if (!noreap)
1375 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
1376 spin_unlock_irq(&p->sighand->siglock);
1378 pid = p->pid;
1379 uid = p->uid;
1380 get_task_struct(p);
1381 read_unlock(&tasklist_lock);
1383 if (!infop) {
1384 retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
1385 put_task_struct(p);
1386 if (!retval && stat_addr)
1387 retval = put_user(0xffff, stat_addr);
1388 if (!retval)
1389 retval = p->pid;
1390 } else {
1391 retval = wait_noreap_copyout(p, pid, uid,
1392 CLD_CONTINUED, SIGCONT,
1393 infop, ru);
1394 BUG_ON(retval == 0);
1397 return retval;
1401 static inline int my_ptrace_child(struct task_struct *p)
1403 if (!(p->ptrace & PT_PTRACED))
1404 return 0;
1405 if (!(p->ptrace & PT_ATTACHED))
1406 return 1;
1408 * This child was PTRACE_ATTACH'd. We should be seeing it only if
1409 * we are the attacher. If we are the real parent, this is a race
1410 * inside ptrace_attach. It is waiting for the tasklist_lock,
1411 * which we have to switch the parent links, but has already set
1412 * the flags in p->ptrace.
1414 return (p->parent != p->real_parent);
1417 static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
1418 int __user *stat_addr, struct rusage __user *ru)
1420 DECLARE_WAITQUEUE(wait, current);
1421 struct task_struct *tsk;
1422 int flag, retval;
1424 add_wait_queue(&current->signal->wait_chldexit,&wait);
1425 repeat:
1427 * We will set this flag if we see any child that might later
1428 * match our criteria, even if we are not able to reap it yet.
1430 flag = 0;
1431 current->state = TASK_INTERRUPTIBLE;
1432 read_lock(&tasklist_lock);
1433 tsk = current;
1434 do {
1435 struct task_struct *p;
1436 struct list_head *_p;
1437 int ret;
1439 list_for_each(_p,&tsk->children) {
1440 p = list_entry(_p,struct task_struct,sibling);
1442 ret = eligible_child(pid, options, p);
1443 if (!ret)
1444 continue;
1446 switch (p->state) {
1447 case TASK_TRACED:
1449 * When we hit the race with PTRACE_ATTACH,
1450 * we will not report this child. But the
1451 * race means it has not yet been moved to
1452 * our ptrace_children list, so we need to
1453 * set the flag here to avoid a spurious ECHILD
1454 * when the race happens with the only child.
1456 flag = 1;
1457 if (!my_ptrace_child(p))
1458 continue;
1459 /*FALLTHROUGH*/
1460 case TASK_STOPPED:
1462 * It's stopped now, so it might later
1463 * continue, exit, or stop again.
1465 flag = 1;
1466 if (!(options & WUNTRACED) &&
1467 !my_ptrace_child(p))
1468 continue;
1469 retval = wait_task_stopped(p, ret == 2,
1470 (options & WNOWAIT),
1471 infop,
1472 stat_addr, ru);
1473 if (retval == -EAGAIN)
1474 goto repeat;
1475 if (retval != 0) /* He released the lock. */
1476 goto end;
1477 break;
1478 default:
1479 // case EXIT_DEAD:
1480 if (p->exit_state == EXIT_DEAD)
1481 continue;
1482 // case EXIT_ZOMBIE:
1483 if (p->exit_state == EXIT_ZOMBIE) {
1485 * Eligible but we cannot release
1486 * it yet:
1488 if (ret == 2)
1489 goto check_continued;
1490 if (!likely(options & WEXITED))
1491 continue;
1492 retval = wait_task_zombie(
1493 p, (options & WNOWAIT),
1494 infop, stat_addr, ru);
1495 /* He released the lock. */
1496 if (retval != 0)
1497 goto end;
1498 break;
1500 check_continued:
1502 * It's running now, so it might later
1503 * exit, stop, or stop and then continue.
1505 flag = 1;
1506 if (!unlikely(options & WCONTINUED))
1507 continue;
1508 retval = wait_task_continued(
1509 p, (options & WNOWAIT),
1510 infop, stat_addr, ru);
1511 if (retval != 0) /* He released the lock. */
1512 goto end;
1513 break;
1516 if (!flag) {
1517 list_for_each(_p, &tsk->ptrace_children) {
1518 p = list_entry(_p, struct task_struct,
1519 ptrace_list);
1520 if (!eligible_child(pid, options, p))
1521 continue;
1522 flag = 1;
1523 break;
1526 if (options & __WNOTHREAD)
1527 break;
1528 tsk = next_thread(tsk);
1529 BUG_ON(tsk->signal != current->signal);
1530 } while (tsk != current);
1532 read_unlock(&tasklist_lock);
1533 if (flag) {
1534 retval = 0;
1535 if (options & WNOHANG)
1536 goto end;
1537 retval = -ERESTARTSYS;
1538 if (signal_pending(current))
1539 goto end;
1540 schedule();
1541 goto repeat;
1543 retval = -ECHILD;
1544 end:
1545 current->state = TASK_RUNNING;
1546 remove_wait_queue(&current->signal->wait_chldexit,&wait);
1547 if (infop) {
1548 if (retval > 0)
1549 retval = 0;
1550 else {
1552 * For a WNOHANG return, clear out all the fields
1553 * we would set so the user can easily tell the
1554 * difference.
1556 if (!retval)
1557 retval = put_user(0, &infop->si_signo);
1558 if (!retval)
1559 retval = put_user(0, &infop->si_errno);
1560 if (!retval)
1561 retval = put_user(0, &infop->si_code);
1562 if (!retval)
1563 retval = put_user(0, &infop->si_pid);
1564 if (!retval)
1565 retval = put_user(0, &infop->si_uid);
1566 if (!retval)
1567 retval = put_user(0, &infop->si_status);
1570 return retval;
1573 asmlinkage long sys_waitid(int which, pid_t pid,
1574 struct siginfo __user *infop, int options,
1575 struct rusage __user *ru)
1577 long ret;
1579 if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
1580 return -EINVAL;
1581 if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
1582 return -EINVAL;
1584 switch (which) {
1585 case P_ALL:
1586 pid = -1;
1587 break;
1588 case P_PID:
1589 if (pid <= 0)
1590 return -EINVAL;
1591 break;
1592 case P_PGID:
1593 if (pid <= 0)
1594 return -EINVAL;
1595 pid = -pid;
1596 break;
1597 default:
1598 return -EINVAL;
1601 ret = do_wait(pid, options, infop, NULL, ru);
1603 /* avoid REGPARM breakage on x86: */
1604 prevent_tail_call(ret);
1605 return ret;
1608 asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr,
1609 int options, struct rusage __user *ru)
1611 long ret;
1613 if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
1614 __WNOTHREAD|__WCLONE|__WALL))
1615 return -EINVAL;
1616 ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru);
1618 /* avoid REGPARM breakage on x86: */
1619 prevent_tail_call(ret);
1620 return ret;
1623 #ifdef __ARCH_WANT_SYS_WAITPID
1626 * sys_waitpid() remains for compatibility. waitpid() should be
1627 * implemented by calling sys_wait4() from libc.a.
1629 asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options)
1631 return sys_wait4(pid, stat_addr, options, NULL);
1634 #endif