1 /*
2 * linux/kernel/exit.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
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/completion.h>
14 #include <linux/personality.h>
15 #include <linux/tty.h>
16 #include <linux/namespace.h>
17 #include <linux/key.h>
18 #include <linux/security.h>
19 #include <linux/cpu.h>
20 #include <linux/acct.h>
21 #include <linux/file.h>
22 #include <linux/binfmts.h>
23 #include <linux/ptrace.h>
24 #include <linux/profile.h>
25 #include <linux/mount.h>
26 #include <linux/proc_fs.h>
27 #include <linux/mempolicy.h>
28 #include <linux/syscalls.h>
29
30 #include <asm/uaccess.h>
31 #include <asm/unistd.h>
32 #include <asm/pgtable.h>
33 #include <asm/mmu_context.h>
34
35 extern void sem_exit (void);
36 extern struct task_struct *child_reaper;
37
38 int getrusage(struct task_struct *, int, struct rusage __user *);
39
40 static void __unhash_process(struct task_struct *p)
41 {
42 nr_threads--;
43 detach_pid(p, PIDTYPE_PID);
44 detach_pid(p, PIDTYPE_TGID);
45 if (thread_group_leader(p)) {
46 detach_pid(p, PIDTYPE_PGID);
47 detach_pid(p, PIDTYPE_SID);
48 if (p->pid)
49 __get_cpu_var(process_counts)--;
50 }
51
52 REMOVE_LINKS(p);
53 }
54
55 void release_task(struct task_struct * p)
56 {
57 int zap_leader;
58 task_t *leader;
59 struct dentry *proc_dentry;
60
61 repeat:
62 atomic_dec(&p->user->processes);
63 spin_lock(&p->proc_lock);
64 proc_dentry = proc_pid_unhash(p);
65 write_lock_irq(&tasklist_lock);
66 if (unlikely(p->ptrace))
67 __ptrace_unlink(p);
68 BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
69 __exit_signal(p);
70 __exit_sighand(p);
71 __unhash_process(p);
72
73 /*
74 * If we are the last non-leader member of the thread
75 * group, and the leader is zombie, then notify the
76 * group leader's parent process. (if it wants notification.)
77 */
78 zap_leader = 0;
79 leader = p->group_leader;
80 if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
81 BUG_ON(leader->exit_signal == -1);
82 do_notify_parent(leader, leader->exit_signal);
83 /*
84 * If we were the last child thread and the leader has
85 * exited already, and the leader's parent ignores SIGCHLD,
86 * then we are the one who should release the leader.
87 *
88 * do_notify_parent() will have marked it self-reaping in
89 * that case.
90 */
91 zap_leader = (leader->exit_signal == -1);
92 }
93
94 sched_exit(p);
95 write_unlock_irq(&tasklist_lock);
96 spin_unlock(&p->proc_lock);
97 proc_pid_flush(proc_dentry);
98 release_thread(p);
99 put_task_struct(p);
100
101 p = leader;
102 if (unlikely(zap_leader))
103 goto repeat;
104 }
105
106 /* we are using it only for SMP init */
107
108 void unhash_process(struct task_struct *p)
109 {
110 struct dentry *proc_dentry;
111
112 spin_lock(&p->proc_lock);
113 proc_dentry = proc_pid_unhash(p);
114 write_lock_irq(&tasklist_lock);
115 __unhash_process(p);
116 write_unlock_irq(&tasklist_lock);
117 spin_unlock(&p->proc_lock);
118 proc_pid_flush(proc_dentry);
119 }
120
121 /*
122 * This checks not only the pgrp, but falls back on the pid if no
123 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
124 * without this...
125 */
126 int session_of_pgrp(int pgrp)
127 {
128 struct task_struct *p;
129 int sid = -1;
130
131 read_lock(&tasklist_lock);
132 do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
133 if (p->signal->session > 0) {
134 sid = p->signal->session;
135 goto out;
136 }
137 } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
138 p = find_task_by_pid(pgrp);
139 if (p)
140 sid = p->signal->session;
141 out:
142 read_unlock(&tasklist_lock);
143
144 return sid;
145 }
146
147 /*
148 * Determine if a process group is "orphaned", according to the POSIX
149 * definition in 2.2.2.52. Orphaned process groups are not to be affected
150 * by terminal-generated stop signals. Newly orphaned process groups are
151 * to receive a SIGHUP and a SIGCONT.
152 *
153 * "I ask you, have you ever known what it is to be an orphan?"
154 */
155 static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task)
156 {
157 struct task_struct *p;
158 int ret = 1;
159
160 do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
161 if (p == ignored_task
162 || p->exit_state
163 || p->real_parent->pid == 1)
164 continue;
165 if (process_group(p->real_parent) != pgrp
166 && p->real_parent->signal->session == p->signal->session) {
167 ret = 0;
168 break;
169 }
170 } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
171 return ret; /* (sighing) "Often!" */
172 }
173
174 int is_orphaned_pgrp(int pgrp)
175 {
176 int retval;
177
178 read_lock(&tasklist_lock);
179 retval = will_become_orphaned_pgrp(pgrp, NULL);
180 read_unlock(&tasklist_lock);
181
182 return retval;
183 }
184
185 static inline int has_stopped_jobs(int pgrp)
186 {
187 int retval = 0;
188 struct task_struct *p;
189
190 do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
191 if (p->state != TASK_STOPPED)
192 continue;
193
194 /* If p is stopped by a debugger on a signal that won't
195 stop it, then don't count p as stopped. This isn't
196 perfect but it's a good approximation. */
197 if (unlikely (p->ptrace)
198 && p->exit_code != SIGSTOP
199 && p->exit_code != SIGTSTP
200 && p->exit_code != SIGTTOU
201 && p->exit_code != SIGTTIN)
202 continue;
203
204 retval = 1;
205 break;
206 } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
207 return retval;
208 }
209
210 /**
211 * reparent_to_init() - Reparent the calling kernel thread to the init task.
212 *
213 * If a kernel thread is launched as a result of a system call, or if
214 * it ever exits, it should generally reparent itself to init so that
215 * it is correctly cleaned up on exit.
216 *
217 * The various task state such as scheduling policy and priority may have
218 * been inherited from a user process, so we reset them to sane values here.
219 *
220 * NOTE that reparent_to_init() gives the caller full capabilities.
221 */
222 void reparent_to_init(void)
223 {
224 write_lock_irq(&tasklist_lock);
225
226 ptrace_unlink(current);
227 /* Reparent to init */
228 REMOVE_LINKS(current);
229 current->parent = child_reaper;
230 current->real_parent = child_reaper;
231 SET_LINKS(current);
232
233 /* Set the exit signal to SIGCHLD so we signal init on exit */
234 current->exit_signal = SIGCHLD;
235
236 if ((current->policy == SCHED_NORMAL) && (task_nice(current) < 0))
237 set_user_nice(current, 0);
238 /* cpus_allowed? */
239 /* rt_priority? */
240 /* signals? */
241 security_task_reparent_to_init(current);
242 memcpy(current->signal->rlim, init_task.signal->rlim,
243 sizeof(current->signal->rlim));
244 atomic_inc(&(INIT_USER->__count));
245 write_unlock_irq(&tasklist_lock);
246 switch_uid(INIT_USER);
247 }
248
249 void __set_special_pids(pid_t session, pid_t pgrp)
250 {
251 struct task_struct *curr = current;
252
253 if (curr->signal->session != session) {
254 detach_pid(curr, PIDTYPE_SID);
255 curr->signal->session = session;
256 attach_pid(curr, PIDTYPE_SID, session);
257 }
258 if (process_group(curr) != pgrp) {
259 detach_pid(curr, PIDTYPE_PGID);
260 curr->signal->pgrp = pgrp;
261 attach_pid(curr, PIDTYPE_PGID, pgrp);
262 }
263 }
264
265 void set_special_pids(pid_t session, pid_t pgrp)
266 {
267 write_lock_irq(&tasklist_lock);
268 __set_special_pids(session, pgrp);
269 write_unlock_irq(&tasklist_lock);
270 }
271
272 /*
273 * Let kernel threads use this to say that they
274 * allow a certain signal (since daemonize() will
275 * have disabled all of them by default).
276 */
277 int allow_signal(int sig)
278 {
279 if (sig < 1 || sig > _NSIG)
280 return -EINVAL;
281
282 spin_lock_irq(¤t->sighand->siglock);
283 sigdelset(¤t->blocked, sig);
284 if (!current->mm) {
285 /* Kernel threads handle their own signals.
286 Let the signal code know it'll be handled, so
287 that they don't get converted to SIGKILL or
288 just silently dropped */
289 current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
290 }
291 recalc_sigpending();
292 spin_unlock_irq(¤t->sighand->siglock);
293 return 0;
294 }
295
296 EXPORT_SYMBOL(allow_signal);
297
298 int disallow_signal(int sig)
299 {
300 if (sig < 1 || sig > _NSIG)
301 return -EINVAL;
302
303 spin_lock_irq(¤t->sighand->siglock);
304 sigaddset(¤t->blocked, sig);
305 recalc_sigpending();
306 spin_unlock_irq(¤t->sighand->siglock);
307 return 0;
308 }
309
310 EXPORT_SYMBOL(disallow_signal);
311
312 /*
313 * Put all the gunge required to become a kernel thread without
314 * attached user resources in one place where it belongs.
315 */
316
317 void daemonize(const char *name, ...)
318 {
319 va_list args;
320 struct fs_struct *fs;
321 sigset_t blocked;
322
323 va_start(args, name);
324 vsnprintf(current->comm, sizeof(current->comm), name, args);
325 va_end(args);
326
327 /*
328 * If we were started as result of loading a module, close all of the
329 * user space pages. We don't need them, and if we didn't close them
330 * they would be locked into memory.
331 */
332 exit_mm(current);
333
334 set_special_pids(1, 1);
335 down(&tty_sem);
336 current->signal->tty = NULL;
337 up(&tty_sem);
338
339 /* Block and flush all signals */
340 sigfillset(&blocked);
341 sigprocmask(SIG_BLOCK, &blocked, NULL);
342 flush_signals(current);
343
344 /* Become as one with the init task */
345
346 exit_fs(current); /* current->fs->count--; */
347 fs = init_task.fs;
348 current->fs = fs;
349 atomic_inc(&fs->count);
350 exit_files(current);
351 current->files = init_task.files;
352 atomic_inc(¤t->files->count);
353
354 reparent_to_init();
355 }
356
357 EXPORT_SYMBOL(daemonize);
358
359 static inline void close_files(struct files_struct * files)
360 {
361 int i, j;
362
363 j = 0;
364 for (;;) {
365 unsigned long set;
366 i = j * __NFDBITS;
367 if (i >= files->max_fdset || i >= files->max_fds)
368 break;
369 set = files->open_fds->fds_bits[j++];
370 while (set) {
371 if (set & 1) {
372 struct file * file = xchg(&files->fd[i], NULL);
373 if (file)
374 filp_close(file, files);
375 }
376 i++;
377 set >>= 1;
378 }
379 }
380 }
381
382 struct files_struct *get_files_struct(struct task_struct *task)
383 {
384 struct files_struct *files;
385
386 task_lock(task);
387 files = task->files;
388 if (files)
389 atomic_inc(&files->count);
390 task_unlock(task);
391
392 return files;
393 }
394
395 void fastcall put_files_struct(struct files_struct *files)
396 {
397 if (atomic_dec_and_test(&files->count)) {
398 close_files(files);
399 /*
400 * Free the fd and fdset arrays if we expanded them.
401 */
402 if (files->fd != &files->fd_array[0])
403 free_fd_array(files->fd, files->max_fds);
404 if (files->max_fdset > __FD_SETSIZE) {
405 free_fdset(files->open_fds, files->max_fdset);
406 free_fdset(files->close_on_exec, files->max_fdset);
407 }
408 kmem_cache_free(files_cachep, files);
409 }
410 }
411
412 EXPORT_SYMBOL(put_files_struct);
413
414 static inline void __exit_files(struct task_struct *tsk)
415 {
416 struct files_struct * files = tsk->files;
417
418 if (files) {
419 task_lock(tsk);
420 tsk->files = NULL;
421 task_unlock(tsk);
422 put_files_struct(files);
423 }
424 }
425
426 void exit_files(struct task_struct *tsk)
427 {
428 __exit_files(tsk);
429 }
430
431 static inline void __put_fs_struct(struct fs_struct *fs)
432 {
433 /* No need to hold fs->lock if we are killing it */
434 if (atomic_dec_and_test(&fs->count)) {
435 dput(fs->root);
436 mntput(fs->rootmnt);
437 dput(fs->pwd);
438 mntput(fs->pwdmnt);
439 if (fs->altroot) {
440 dput(fs->altroot);
441 mntput(fs->altrootmnt);
442 }
443 kmem_cache_free(fs_cachep, fs);
444 }
445 }
446
447 void put_fs_struct(struct fs_struct *fs)
448 {
449 __put_fs_struct(fs);
450 }
451
452 static inline void __exit_fs(struct task_struct *tsk)
453 {
454 struct fs_struct * fs = tsk->fs;
455
456 if (fs) {
457 task_lock(tsk);
458 tsk->fs = NULL;
459 task_unlock(tsk);
460 __put_fs_struct(fs);
461 }
462 }
463
464 void exit_fs(struct task_struct *tsk)
465 {
466 __exit_fs(tsk);
467 }
468
469 EXPORT_SYMBOL_GPL(exit_fs);
470
471 /*
472 * Turn us into a lazy TLB process if we
473 * aren't already..
474 */
475 void exit_mm(struct task_struct * tsk)
476 {
477 struct mm_struct *mm = tsk->mm;
478
479 mm_release(tsk, mm);
480 if (!mm)
481 return;
482 /*
483 * Serialize with any possible pending coredump.
484 * We must hold mmap_sem around checking core_waiters
485 * and clearing tsk->mm. The core-inducing thread
486 * will increment core_waiters for each thread in the
487 * group with ->mm != NULL.
488 */
489 down_read(&mm->mmap_sem);
490 if (mm->core_waiters) {
491 up_read(&mm->mmap_sem);
492 down_write(&mm->mmap_sem);
493 if (!--mm->core_waiters)
494 complete(mm->core_startup_done);
495 up_write(&mm->mmap_sem);
496
497 wait_for_completion(&mm->core_done);
498 down_read(&mm->mmap_sem);
499 }
500 atomic_inc(&mm->mm_count);
501 if (mm != tsk->active_mm) BUG();
502 /* more a memory barrier than a real lock */
503 task_lock(tsk);
504 tsk->mm = NULL;
505 up_read(&mm->mmap_sem);
506 enter_lazy_tlb(mm, current);
507 task_unlock(tsk);
508 mmput(mm);
509 }
510
511 static inline void choose_new_parent(task_t *p, task_t *reaper, task_t *child_reaper)
512 {
513 /*
514 * Make sure we're not reparenting to ourselves and that
515 * the parent is not a zombie.
516 */
517 BUG_ON(p == reaper || reaper->exit_state >= EXIT_ZOMBIE);
518 p->real_parent = reaper;
519 if (p->parent == p->real_parent)
520 BUG();
521 }
522
523 static inline void reparent_thread(task_t *p, task_t *father, int traced)
524 {
525 /* We don't want people slaying init. */
526 if (p->exit_signal != -1)
527 p->exit_signal = SIGCHLD;
528
529 if (p->pdeath_signal)
530 /* We already hold the tasklist_lock here. */
531 group_send_sig_info(p->pdeath_signal, (void *) 0, p);
532
533 /* Move the child from its dying parent to the new one. */
534 if (unlikely(traced)) {
535 /* Preserve ptrace links if someone else is tracing this child. */
536 list_del_init(&p->ptrace_list);
537 if (p->parent != p->real_parent)
538 list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
539 } else {
540 /* If this child is being traced, then we're the one tracing it
541 * anyway, so let go of it.
542 */
543 p->ptrace = 0;
544 list_del_init(&p->sibling);
545 p->parent = p->real_parent;
546 list_add_tail(&p->sibling, &p->parent->children);
547
548 /* If we'd notified the old parent about this child's death,
549 * also notify the new parent.
550 */
551 if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
552 thread_group_empty(p))
553 do_notify_parent(p, p->exit_signal);
554 else if (p->state == TASK_TRACED) {
555 /*
556 * If it was at a trace stop, turn it into
557 * a normal stop since it's no longer being
558 * traced.
559 */
560 ptrace_untrace(p);
561 }
562 }
563
564 /*
565 * process group orphan check
566 * Case ii: Our child is in a different pgrp
567 * than we are, and it was the only connection
568 * outside, so the child pgrp is now orphaned.
569 */
570 if ((process_group(p) != process_group(father)) &&
571 (p->signal->session == father->signal->session)) {
572 int pgrp = process_group(p);
573
574 if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
575 __kill_pg_info(SIGHUP, (void *)1, pgrp);
576 __kill_pg_info(SIGCONT, (void *)1, pgrp);
577 }
578 }
579 }
580
581 /*
582 * When we die, we re-parent all our children.
583 * Try to give them to another thread in our thread
584 * group, and if no such member exists, give it to
585 * the global child reaper process (ie "init")
586 */
587 static inline void forget_original_parent(struct task_struct * father,
588 struct list_head *to_release)
589 {
590 struct task_struct *p, *reaper = father;
591 struct list_head *_p, *_n;
592
593 do {
594 reaper = next_thread(reaper);
595 if (reaper == father) {
596 reaper = child_reaper;
597 break;
598 }
599 } while (reaper->exit_state);
600
601 /*
602 * There are only two places where our children can be:
603 *
604 * - in our child list
605 * - in our ptraced child list
606 *
607 * Search them and reparent children.
608 */
609 list_for_each_safe(_p, _n, &father->children) {
610 int ptrace;
611 p = list_entry(_p,struct task_struct,sibling);
612
613 ptrace = p->ptrace;
614
615 /* if father isn't the real parent, then ptrace must be enabled */
616 BUG_ON(father != p->real_parent && !ptrace);
617
618 if (father == p->real_parent) {
619 /* reparent with a reaper, real father it's us */
620 choose_new_parent(p, reaper, child_reaper);
621 reparent_thread(p, father, 0);
622 } else {
623 /* reparent ptraced task to its real parent */
624 __ptrace_unlink (p);
625 if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
626 thread_group_empty(p))
627 do_notify_parent(p, p->exit_signal);
628 }
629
630 /*
631 * if the ptraced child is a zombie with exit_signal == -1
632 * we must collect it before we exit, or it will remain
633 * zombie forever since we prevented it from self-reap itself
634 * while it was being traced by us, to be able to see it in wait4.
635 */
636 if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1))
637 list_add(&p->ptrace_list, to_release);
638 }
639 list_for_each_safe(_p, _n, &father->ptrace_children) {
640 p = list_entry(_p,struct task_struct,ptrace_list);
641 choose_new_parent(p, reaper, child_reaper);
642 reparent_thread(p, father, 1);
643 }
644 }
645
646 /*
647 * Send signals to all our closest relatives so that they know
648 * to properly mourn us..
649 */
650 static void exit_notify(struct task_struct *tsk)
651 {
652 int state;
653 struct task_struct *t;
654 struct list_head ptrace_dead, *_p, *_n;
655
656 if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT)
657 && !thread_group_empty(tsk)) {
658 /*
659 * This occurs when there was a race between our exit
660 * syscall and a group signal choosing us as the one to
661 * wake up. It could be that we are the only thread
662 * alerted to check for pending signals, but another thread
663 * should be woken now to take the signal since we will not.
664 * Now we'll wake all the threads in the group just to make
665 * sure someone gets all the pending signals.
666 */
667 read_lock(&tasklist_lock);
668 spin_lock_irq(&tsk->sighand->siglock);
669 for (t = next_thread(tsk); t != tsk; t = next_thread(t))
670 if (!signal_pending(t) && !(t->flags & PF_EXITING)) {
671 recalc_sigpending_tsk(t);
672 if (signal_pending(t))
673 signal_wake_up(t, 0);
674 }
675 spin_unlock_irq(&tsk->sighand->siglock);
676 read_unlock(&tasklist_lock);
677 }
678
679 write_lock_irq(&tasklist_lock);
680
681 /*
682 * This does two things:
683 *
684 * A. Make init inherit all the child processes
685 * B. Check to see if any process groups have become orphaned
686 * as a result of our exiting, and if they have any stopped
687 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
688 */
689
690 INIT_LIST_HEAD(&ptrace_dead);
691 forget_original_parent(tsk, &ptrace_dead);
692 BUG_ON(!list_empty(&tsk->children));
693 BUG_ON(!list_empty(&tsk->ptrace_children));
694
695 /*
696 * Check to see if any process groups have become orphaned
697 * as a result of our exiting, and if they have any stopped
698 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
699 *
700 * Case i: Our father is in a different pgrp than we are
701 * and we were the only connection outside, so our pgrp
702 * is about to become orphaned.
703 */
704
705 t = tsk->real_parent;
706
707 if ((process_group(t) != process_group(tsk)) &&
708 (t->signal->session == tsk->signal->session) &&
709 will_become_orphaned_pgrp(process_group(tsk), tsk) &&
710 has_stopped_jobs(process_group(tsk))) {
711 __kill_pg_info(SIGHUP, (void *)1, process_group(tsk));
712 __kill_pg_info(SIGCONT, (void *)1, process_group(tsk));
713 }
714
715 /* Let father know we died
716 *
717 * Thread signals are configurable, but you aren't going to use
718 * that to send signals to arbitary processes.
719 * That stops right now.
720 *
721 * If the parent exec id doesn't match the exec id we saved
722 * when we started then we know the parent has changed security
723 * domain.
724 *
725 * If our self_exec id doesn't match our parent_exec_id then
726 * we have changed execution domain as these two values started
727 * the same after a fork.
728 *
729 */
730
731 if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
732 ( tsk->parent_exec_id != t->self_exec_id ||
733 tsk->self_exec_id != tsk->parent_exec_id)
734 && !capable(CAP_KILL))
735 tsk->exit_signal = SIGCHLD;
736
737
738 /* If something other than our normal parent is ptracing us, then
739 * send it a SIGCHLD instead of honoring exit_signal. exit_signal
740 * only has special meaning to our real parent.
741 */
742 if (tsk->exit_signal != -1 && thread_group_empty(tsk)) {
743 int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD;
744 do_notify_parent(tsk, signal);
745 } else if (tsk->ptrace) {
746 do_notify_parent(tsk, SIGCHLD);
747 }
748
749 state = EXIT_ZOMBIE;
750 if (tsk->exit_signal == -1 &&
751 (likely(tsk->ptrace == 0) ||
752 unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT)))
753 state = EXIT_DEAD;
754 tsk->exit_state = state;
755
756 /*
757 * Clear these here so that update_process_times() won't try to deliver
758 * itimer, profile or rlimit signals to this task while it is in late exit.
759 */
760 tsk->it_virt_value = cputime_zero;
761 tsk->it_prof_value = cputime_zero;
762
763 write_unlock_irq(&tasklist_lock);
764
765 list_for_each_safe(_p, _n, &ptrace_dead) {
766 list_del_init(_p);
767 t = list_entry(_p,struct task_struct,ptrace_list);
768 release_task(t);
769 }
770
771 /* If the process is dead, release it - nobody will wait for it */
772 if (state == EXIT_DEAD)
773 release_task(tsk);
774
775 /* PF_DEAD causes final put_task_struct after we schedule. */
776 preempt_disable();
777 tsk->flags |= PF_DEAD;
778 }
779
780 fastcall NORET_TYPE void do_exit(long code)
781 {
782 struct task_struct *tsk = current;
783 int group_dead;
784
785 profile_task_exit(tsk);
786
787 if (unlikely(in_interrupt()))
788 panic("Aiee, killing interrupt handler!");
789 if (unlikely(!tsk->pid))
790 panic("Attempted to kill the idle task!");
791 if (unlikely(tsk->pid == 1))
792 panic("Attempted to kill init!");
793 if (tsk->io_context)
794 exit_io_context();
795
796 if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
797 current->ptrace_message = code;
798 ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
799 }
800
801 tsk->flags |= PF_EXITING;
802 del_timer_sync(&tsk->real_timer);
803
804 if (unlikely(in_atomic()))
805 printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
806 current->comm, current->pid,
807 preempt_count());
808
809 acct_update_integrals();
810 update_mem_hiwater();
811 group_dead = atomic_dec_and_test(&tsk->signal->live);
812 if (group_dead)
813 acct_process(code);
814 exit_mm(tsk);
815
816 exit_sem(tsk);
817 __exit_files(tsk);
818 __exit_fs(tsk);
819 exit_namespace(tsk);
820 exit_thread();
821 exit_keys(tsk);
822
823 if (group_dead && tsk->signal->leader)
824 disassociate_ctty(1);
825
826 module_put(tsk->thread_info->exec_domain->module);
827 if (tsk->binfmt)
828 module_put(tsk->binfmt->module);
829
830 tsk->exit_code = code;
831 exit_notify(tsk);
832 #ifdef CONFIG_NUMA
833 mpol_free(tsk->mempolicy);
834 tsk->mempolicy = NULL;
835 #endif
836
837 BUG_ON(!(current->flags & PF_DEAD));
838 schedule();
839 BUG();
840 /* Avoid "noreturn function does return". */
841 for (;;) ;
842 }
843
844 NORET_TYPE void complete_and_exit(struct completion *comp, long code)
845 {
846 if (comp)
847 complete(comp);
848
849 do_exit(code);
850 }
851
852 EXPORT_SYMBOL(complete_and_exit);
853
854 asmlinkage long sys_exit(int error_code)
855 {
856 do_exit((error_code&0xff)<<8);
857 }
858
859 task_t fastcall *next_thread(const task_t *p)
860 {
861 return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID);
862 }
863
864 EXPORT_SYMBOL(next_thread);
865
866 /*
867 * Take down every thread in the group. This is called by fatal signals
868 * as well as by sys_exit_group (below).
869 */
870 NORET_TYPE void
871 do_group_exit(int exit_code)
872 {
873 BUG_ON(exit_code & 0x80); /* core dumps don't get here */
874
875 if (current->signal->flags & SIGNAL_GROUP_EXIT)
876 exit_code = current->signal->group_exit_code;
877 else if (!thread_group_empty(current)) {
878 struct signal_struct *const sig = current->signal;
879 struct sighand_struct *const sighand = current->sighand;
880 read_lock(&tasklist_lock);
881 spin_lock_irq(&sighand->siglock);
882 if (sig->flags & SIGNAL_GROUP_EXIT)
883 /* Another thread got here before we took the lock. */
884 exit_code = sig->group_exit_code;
885 else {
886 sig->flags = SIGNAL_GROUP_EXIT;
887 sig->group_exit_code = exit_code;
888 zap_other_threads(current);
889 }
890 spin_unlock_irq(&sighand->siglock);
891 read_unlock(&tasklist_lock);
892 }
893
894 do_exit(exit_code);
895 /* NOTREACHED */
896 }
897
898 /*
899 * this kills every thread in the thread group. Note that any externally
900 * wait4()-ing process will get the correct exit code - even if this
901 * thread is not the thread group leader.
902 */
903 asmlinkage void sys_exit_group(int error_code)
904 {
905 do_group_exit((error_code & 0xff) << 8);
906 }
907
908 static int eligible_child(pid_t pid, int options, task_t *p)
909 {
910 if (pid > 0) {
911 if (p->pid != pid)
912 return 0;
913 } else if (!pid) {
914 if (process_group(p) != process_group(current))
915 return 0;
916 } else if (pid != -1) {
917 if (process_group(p) != -pid)
918 return 0;
919 }
920
921 /*
922 * Do not consider detached threads that are
923 * not ptraced:
924 */
925 if (p->exit_signal == -1 && !p->ptrace)
926 return 0;
927
928 /* Wait for all children (clone and not) if __WALL is set;
929 * otherwise, wait for clone children *only* if __WCLONE is
930 * set; otherwise, wait for non-clone children *only*. (Note:
931 * A "clone" child here is one that reports to its parent
932 * using a signal other than SIGCHLD.) */
933 if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
934 && !(options & __WALL))
935 return 0;
936 /*
937 * Do not consider thread group leaders that are
938 * in a non-empty thread group:
939 */
940 if (current->tgid != p->tgid && delay_group_leader(p))
941 return 2;
942
943 if (security_task_wait(p))
944 return 0;
945
946 return 1;
947 }
948
949 static int wait_noreap_copyout(task_t *p, pid_t pid, uid_t uid,
950 int why, int status,
951 struct siginfo __user *infop,
952 struct rusage __user *rusagep)
953 {
954 int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0;
955 put_task_struct(p);
956 if (!retval)
957 retval = put_user(SIGCHLD, &infop->si_signo);
958 if (!retval)
959 retval = put_user(0, &infop->si_errno);
960 if (!retval)
961 retval = put_user((short)why, &infop->si_code);
962 if (!retval)
963 retval = put_user(pid, &infop->si_pid);
964 if (!retval)
965 retval = put_user(uid, &infop->si_uid);
966 if (!retval)
967 retval = put_user(status, &infop->si_status);
968 if (!retval)
969 retval = pid;
970 return retval;
971 }
972
973 /*
974 * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold
975 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
976 * the lock and this task is uninteresting. If we return nonzero, we have
977 * released the lock and the system call should return.
978 */
979 static int wait_task_zombie(task_t *p, int noreap,
980 struct siginfo __user *infop,
981 int __user *stat_addr, struct rusage __user *ru)
982 {
983 unsigned long state;
984 int retval;
985 int status;
986
987 if (unlikely(noreap)) {
988 pid_t pid = p->pid;
989 uid_t uid = p->uid;
990 int exit_code = p->exit_code;
991 int why, status;
992
993 if (unlikely(p->exit_state != EXIT_ZOMBIE))
994 return 0;
995 if (unlikely(p->exit_signal == -1 && p->ptrace == 0))
996 return 0;
997 get_task_struct(p);
998 read_unlock(&tasklist_lock);
999 if ((exit_code & 0x7f) == 0) {
1000 why = CLD_EXITED;
1001 status = exit_code >> 8;
1002 } else {
1003 why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
1004 status = exit_code & 0x7f;
1005 }
1006 return wait_noreap_copyout(p, pid, uid, why,
1007 status, infop, ru);
1008 }
1009
1010 /*
1011 * Try to move the task's state to DEAD
1012 * only one thread is allowed to do this:
1013 */
1014 state = xchg(&p->exit_state, EXIT_DEAD);
1015 if (state != EXIT_ZOMBIE) {
1016 BUG_ON(state != EXIT_DEAD);
1017 return 0;
1018 }
1019 if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) {
1020 /*
1021 * This can only happen in a race with a ptraced thread
1022 * dying on another processor.
1023 */
1024 return 0;
1025 }
1026
1027 if (likely(p->real_parent == p->parent) && likely(p->signal)) {
1028 /*
1029 * The resource counters for the group leader are in its
1030 * own task_struct. Those for dead threads in the group
1031 * are in its signal_struct, as are those for the child
1032 * processes it has previously reaped. All these
1033 * accumulate in the parent's signal_struct c* fields.
1034 *
1035 * We don't bother to take a lock here to protect these
1036 * p->signal fields, because they are only touched by
1037 * __exit_signal, which runs with tasklist_lock
1038 * write-locked anyway, and so is excluded here. We do
1039 * need to protect the access to p->parent->signal fields,
1040 * as other threads in the parent group can be right
1041 * here reaping other children at the same time.
1042 */
1043 spin_lock_irq(&p->parent->sighand->siglock);
1044 p->parent->signal->cutime =
1045 cputime_add(p->parent->signal->cutime,
1046 cputime_add(p->utime,
1047 cputime_add(p->signal->utime,
1048 p->signal->cutime)));
1049 p->parent->signal->cstime =
1050 cputime_add(p->parent->signal->cstime,
1051 cputime_add(p->stime,
1052 cputime_add(p->signal->stime,
1053 p->signal->cstime)));
1054 p->parent->signal->cmin_flt +=
1055 p->min_flt + p->signal->min_flt + p->signal->cmin_flt;
1056 p->parent->signal->cmaj_flt +=
1057 p->maj_flt + p->signal->maj_flt + p->signal->cmaj_flt;
1058 p->parent->signal->cnvcsw +=
1059 p->nvcsw + p->signal->nvcsw + p->signal->cnvcsw;
1060 p->parent->signal->cnivcsw +=
1061 p->nivcsw + p->signal->nivcsw + p->signal->cnivcsw;
1062 spin_unlock_irq(&p->parent->sighand->siglock);
1063 }
1064
1065 /*
1066 * Now we are sure this task is interesting, and no other
1067 * thread can reap it because we set its state to EXIT_DEAD.
1068 */
1069 read_unlock(&tasklist_lock);
1070
1071 retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
1072 status = (p->signal->flags & SIGNAL_GROUP_EXIT)
1073 ? p->signal->group_exit_code : p->exit_code;
1074 if (!retval && stat_addr)
1075 retval = put_user(status, stat_addr);
1076 if (!retval && infop)
1077 retval = put_user(SIGCHLD, &infop->si_signo);
1078 if (!retval && infop)
1079 retval = put_user(0, &infop->si_errno);
1080 if (!retval && infop) {
1081 int why;
1082
1083 if ((status & 0x7f) == 0) {
1084 why = CLD_EXITED;
1085 status >>= 8;
1086 } else {
1087 why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
1088 status &= 0x7f;
1089 }
1090 retval = put_user((short)why, &infop->si_code);
1091 if (!retval)
1092 retval = put_user(status, &infop->si_status);
1093 }
1094 if (!retval && infop)
1095 retval = put_user(p->pid, &infop->si_pid);
1096 if (!retval && infop)
1097 retval = put_user(p->uid, &infop->si_uid);
1098 if (retval) {
1099 // TODO: is this safe?
1100 p->exit_state = EXIT_ZOMBIE;
1101 return retval;
1102 }
1103 retval = p->pid;
1104 if (p->real_parent != p->parent) {
1105 write_lock_irq(&tasklist_lock);
1106 /* Double-check with lock held. */
1107 if (p->real_parent != p->parent) {
1108 __ptrace_unlink(p);
1109 // TODO: is this safe?
1110 p->exit_state = EXIT_ZOMBIE;
1111 /*
1112 * If this is not a detached task, notify the parent.
1113 * If it's still not detached after that, don't release
1114 * it now.
1115 */
1116 if (p->exit_signal != -1) {
1117 do_notify_parent(p, p->exit_signal);
1118 if (p->exit_signal != -1)
1119 p = NULL;
1120 }
1121 }
1122 write_unlock_irq(&tasklist_lock);
1123 }
1124 if (p != NULL)
1125 release_task(p);
1126 BUG_ON(!retval);
1127 return retval;
1128 }
1129
1130 /*
1131 * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
1132 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1133 * the lock and this task is uninteresting. If we return nonzero, we have
1134 * released the lock and the system call should return.
1135 */
1136 static int wait_task_stopped(task_t *p, int delayed_group_leader, int noreap,
1137 struct siginfo __user *infop,
1138 int __user *stat_addr, struct rusage __user *ru)
1139 {
1140 int retval, exit_code;
1141
1142 if (!p->exit_code)
1143 return 0;
1144 if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
1145 p->signal && p->signal->group_stop_count > 0)
1146 /*
1147 * A group stop is in progress and this is the group leader.
1148 * We won't report until all threads have stopped.
1149 */
1150 return 0;
1151
1152 /*
1153 * Now we are pretty sure this task is interesting.
1154 * Make sure it doesn't get reaped out from under us while we
1155 * give up the lock and then examine it below. We don't want to
1156 * keep holding onto the tasklist_lock while we call getrusage and
1157 * possibly take page faults for user memory.
1158 */
1159 get_task_struct(p);
1160 read_unlock(&tasklist_lock);
1161
1162 if (unlikely(noreap)) {
1163 pid_t pid = p->pid;
1164 uid_t uid = p->uid;
1165 int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
1166
1167 exit_code = p->exit_code;
1168 if (unlikely(!exit_code) ||
1169 unlikely(p->state > TASK_STOPPED))
1170 goto bail_ref;
1171 return wait_noreap_copyout(p, pid, uid,
1172 why, (exit_code << 8) | 0x7f,
1173 infop, ru);
1174 }
1175
1176 write_lock_irq(&tasklist_lock);
1177
1178 /*
1179 * This uses xchg to be atomic with the thread resuming and setting
1180 * it. It must also be done with the write lock held to prevent a
1181 * race with the EXIT_ZOMBIE case.
1182 */
1183 exit_code = xchg(&p->exit_code, 0);
1184 if (unlikely(p->exit_state)) {
1185 /*
1186 * The task resumed and then died. Let the next iteration
1187 * catch it in EXIT_ZOMBIE. Note that exit_code might
1188 * already be zero here if it resumed and did _exit(0).
1189 * The task itself is dead and won't touch exit_code again;
1190 * other processors in this function are locked out.
1191 */
1192 p->exit_code = exit_code;
1193 exit_code = 0;
1194 }
1195 if (unlikely(exit_code == 0)) {
1196 /*
1197 * Another thread in this function got to it first, or it
1198 * resumed, or it resumed and then died.
1199 */
1200 write_unlock_irq(&tasklist_lock);
1201 bail_ref:
1202 put_task_struct(p);
1203 /*
1204 * We are returning to the wait loop without having successfully
1205 * removed the process and having released the lock. We cannot
1206 * continue, since the "p" task pointer is potentially stale.
1207 *
1208 * Return -EAGAIN, and do_wait() will restart the loop from the
1209 * beginning. Do _not_ re-acquire the lock.
1210 */
1211 return -EAGAIN;
1212 }
1213
1214 /* move to end of parent's list to avoid starvation */
1215 remove_parent(p);
1216 add_parent(p, p->parent);
1217
1218 write_unlock_irq(&tasklist_lock);
1219
1220 retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
1221 if (!retval && stat_addr)
1222 retval = put_user((exit_code << 8) | 0x7f, stat_addr);
1223 if (!retval && infop)
1224 retval = put_user(SIGCHLD, &infop->si_signo);
1225 if (!retval && infop)
1226 retval = put_user(0, &infop->si_errno);
1227 if (!retval && infop)
1228 retval = put_user((short)((p->ptrace & PT_PTRACED)
1229 ? CLD_TRAPPED : CLD_STOPPED),
1230 &infop->si_code);
1231 if (!retval && infop)
1232 retval = put_user(exit_code, &infop->si_status);
1233 if (!retval && infop)
1234 retval = put_user(p->pid, &infop->si_pid);
1235 if (!retval && infop)
1236 retval = put_user(p->uid, &infop->si_uid);
1237 if (!retval)
1238 retval = p->pid;
1239 put_task_struct(p);
1240
1241 BUG_ON(!retval);
1242 return retval;
1243 }
1244
1245 /*
1246 * Handle do_wait work for one task in a live, non-stopped state.
1247 * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
1248 * the lock and this task is uninteresting. If we return nonzero, we have
1249 * released the lock and the system call should return.
1250 */
1251 static int wait_task_continued(task_t *p, int noreap,
1252 struct siginfo __user *infop,
1253 int __user *stat_addr, struct rusage __user *ru)
1254 {
1255 int retval;
1256 pid_t pid;
1257 uid_t uid;
1258
1259 if (unlikely(!p->signal))
1260 return 0;
1261
1262 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
1263 return 0;
1264
1265 spin_lock_irq(&p->sighand->siglock);
1266 /* Re-check with the lock held. */
1267 if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) {
1268 spin_unlock_irq(&p->sighand->siglock);
1269 return 0;
1270 }
1271 if (!noreap)
1272 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
1273 spin_unlock_irq(&p->sighand->siglock);
1274
1275 pid = p->pid;
1276 uid = p->uid;
1277 get_task_struct(p);
1278 read_unlock(&tasklist_lock);
1279
1280 if (!infop) {
1281 retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
1282 put_task_struct(p);
1283 if (!retval && stat_addr)
1284 retval = put_user(0xffff, stat_addr);
1285 if (!retval)
1286 retval = p->pid;
1287 } else {
1288 retval = wait_noreap_copyout(p, pid, uid,
1289 CLD_CONTINUED, SIGCONT,
1290 infop, ru);
1291 BUG_ON(retval == 0);
1292 }
1293
1294 return retval;
1295 }
1296
1297
1298 static inline int my_ptrace_child(struct task_struct *p)
1299 {
1300 if (!(p->ptrace & PT_PTRACED))
1301 return 0;
1302 if (!(p->ptrace & PT_ATTACHED))
1303 return 1;
1304 /*
1305 * This child was PTRACE_ATTACH'd. We should be seeing it only if
1306 * we are the attacher. If we are the real parent, this is a race
1307 * inside ptrace_attach. It is waiting for the tasklist_lock,
1308 * which we have to switch the parent links, but has already set
1309 * the flags in p->ptrace.
1310 */
1311 return (p->parent != p->real_parent);
1312 }
1313
1314 static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
1315 int __user *stat_addr, struct rusage __user *ru)
1316 {
1317 DECLARE_WAITQUEUE(wait, current);
1318 struct task_struct *tsk;
1319 int flag, retval;
1320
1321 add_wait_queue(¤t->signal->wait_chldexit,&wait);
1322 repeat:
1323 /*
1324 * We will set this flag if we see any child that might later
1325 * match our criteria, even if we are not able to reap it yet.
1326 */
1327 flag = 0;
1328 current->state = TASK_INTERRUPTIBLE;
1329 read_lock(&tasklist_lock);
1330 tsk = current;
1331 do {
1332 struct task_struct *p;
1333 struct list_head *_p;
1334 int ret;
1335
1336 list_for_each(_p,&tsk->children) {
1337 p = list_entry(_p,struct task_struct,sibling);
1338
1339 ret = eligible_child(pid, options, p);
1340 if (!ret)
1341 continue;
1342
1343 switch (p->state) {
1344 case TASK_TRACED:
1345 if (!my_ptrace_child(p))
1346 continue;
1347 /*FALLTHROUGH*/
1348 case TASK_STOPPED:
1349 /*
1350 * It's stopped now, so it might later
1351 * continue, exit, or stop again.
1352 */
1353 flag = 1;
1354 if (!(options & WUNTRACED) &&
1355 !my_ptrace_child(p))
1356 continue;
1357 retval = wait_task_stopped(p, ret == 2,
1358 (options & WNOWAIT),
1359 infop,
1360 stat_addr, ru);
1361 if (retval == -EAGAIN)
1362 goto repeat;
1363 if (retval != 0) /* He released the lock. */
1364 goto end;
1365 break;
1366 default:
1367 // case EXIT_DEAD:
1368 if (p->exit_state == EXIT_DEAD)
1369 continue;
1370 // case EXIT_ZOMBIE:
1371 if (p->exit_state == EXIT_ZOMBIE) {
1372 /*
1373 * Eligible but we cannot release
1374 * it yet:
1375 */
1376 if (ret == 2)
1377 goto check_continued;
1378 if (!likely(options & WEXITED))
1379 continue;
1380 retval = wait_task_zombie(
1381 p, (options & WNOWAIT),
1382 infop, stat_addr, ru);
1383 /* He released the lock. */
1384 if (retval != 0)
1385 goto end;
1386 break;
1387 }
1388 check_continued:
1389 /*
1390 * It's running now, so it might later
1391 * exit, stop, or stop and then continue.
1392 */
1393 flag = 1;
1394 if (!unlikely(options & WCONTINUED))
1395 continue;
1396 retval = wait_task_continued(
1397 p, (options & WNOWAIT),
1398 infop, stat_addr, ru);
1399 if (retval != 0) /* He released the lock. */
1400 goto end;
1401 break;
1402 }
1403 }
1404 if (!flag) {
1405 list_for_each(_p, &tsk->ptrace_children) {
1406 p = list_entry(_p, struct task_struct,
1407 ptrace_list);
1408 if (!eligible_child(pid, options, p))
1409 continue;
1410 flag = 1;
1411 break;
1412 }
1413 }
1414 if (options & __WNOTHREAD)
1415 break;
1416 tsk = next_thread(tsk);
1417 if (tsk->signal != current->signal)
1418 BUG();
1419 } while (tsk != current);
1420
1421 read_unlock(&tasklist_lock);
1422 if (flag) {
1423 retval = 0;
1424 if (options & WNOHANG)
1425 goto end;
1426 retval = -ERESTARTSYS;
1427 if (signal_pending(current))
1428 goto end;
1429 schedule();
1430 goto repeat;
1431 }
1432 retval = -ECHILD;
1433 end:
1434 current->state = TASK_RUNNING;
1435 remove_wait_queue(¤t->signal->wait_chldexit,&wait);
1436 if (infop) {
1437 if (retval > 0)
1438 retval = 0;
1439 else {
1440 /*
1441 * For a WNOHANG return, clear out all the fields
1442 * we would set so the user can easily tell the
1443 * difference.
1444 */
1445 if (!retval)
1446 retval = put_user(0, &infop->si_signo);
1447 if (!retval)
1448 retval = put_user(0, &infop->si_errno);
1449 if (!retval)
1450 retval = put_user(0, &infop->si_code);
1451 if (!retval)
1452 retval = put_user(0, &infop->si_pid);
1453 if (!retval)
1454 retval = put_user(0, &infop->si_uid);
1455 if (!retval)
1456 retval = put_user(0, &infop->si_status);
1457 }
1458 }
1459 return retval;
1460 }
1461
1462 asmlinkage long sys_waitid(int which, pid_t pid,
1463 struct siginfo __user *infop, int options,
1464 struct rusage __user *ru)
1465 {
1466 long ret;
1467
1468 if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
1469 return -EINVAL;
1470 if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
1471 return -EINVAL;
1472
1473 switch (which) {
1474 case P_ALL:
1475 pid = -1;
1476 break;
1477 case P_PID:
1478 if (pid <= 0)
1479 return -EINVAL;
1480 break;
1481 case P_PGID:
1482 if (pid <= 0)
1483 return -EINVAL;
1484 pid = -pid;
1485 break;
1486 default:
1487 return -EINVAL;
1488 }
1489
1490 ret = do_wait(pid, options, infop, NULL, ru);
1491
1492 /* avoid REGPARM breakage on x86: */
1493 prevent_tail_call(ret);
1494 return ret;
1495 }
1496
1497 asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr,
1498 int options, struct rusage __user *ru)
1499 {
1500 long ret;
1501
1502 if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
1503 __WNOTHREAD|__WCLONE|__WALL))
1504 return -EINVAL;
1505 ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru);
1506
1507 /* avoid REGPARM breakage on x86: */
1508 prevent_tail_call(ret);
1509 return ret;
1510 }
1511
1512 #ifdef __ARCH_WANT_SYS_WAITPID
1513
1514 /*
1515 * sys_waitpid() remains for compatibility. waitpid() should be
1516 * implemented by calling sys_wait4() from libc.a.
1517 */
1518 asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options)
1519 {
1520 return sys_wait4(pid, stat_addr, options, NULL);
1521 }
1522
1523 #endif
1524
|
This page was automatically generated by the
LXR engine.
|