FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exit.c
1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/6.2/sys/kern/kern_exit.c 164286 2006-11-14 20:42:41Z cvs2svn $");
39
40 #include "opt_compat.h"
41 #include "opt_ktrace.h"
42 #include "opt_mac.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysproto.h>
47 #include <sys/eventhandler.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/proc.h>
53 #include <sys/pioctl.h>
54 #include <sys/tty.h>
55 #include <sys/wait.h>
56 #include <sys/vmmeter.h>
57 #include <sys/vnode.h>
58 #include <sys/resourcevar.h>
59 #include <sys/signalvar.h>
60 #include <sys/sched.h>
61 #include <sys/sx.h>
62 #include <sys/syscallsubr.h>
63 #include <sys/ptrace.h>
64 #include <sys/acct.h> /* for acct_process() function prototype */
65 #include <sys/filedesc.h>
66 #include <sys/mac.h>
67 #include <sys/shm.h>
68 #include <sys/sem.h>
69 #ifdef KTRACE
70 #include <sys/ktrace.h>
71 #endif
72
73 #include <security/audit/audit.h>
74
75 #include <vm/vm.h>
76 #include <vm/vm_extern.h>
77 #include <vm/vm_param.h>
78 #include <vm/pmap.h>
79 #include <vm/vm_map.h>
80 #include <vm/vm_page.h>
81 #include <vm/uma.h>
82
83 /* Required to be non-static for SysVR4 emulator */
84 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
85
86 /* Hook for NFS teardown procedure. */
87 void (*nlminfo_release_p)(struct proc *p);
88
89 /*
90 * exit --
91 * Death of process.
92 *
93 * MPSAFE
94 */
95 void
96 sys_exit(struct thread *td, struct sys_exit_args *uap)
97 {
98
99 exit1(td, W_EXITCODE(uap->rval, 0));
100 /* NOTREACHED */
101 }
102
103 /*
104 * Exit: deallocate address space and other resources, change proc state
105 * to zombie, and unlink proc from allproc and parent's lists. Save exit
106 * status and rusage for wait(). Check for child processes and orphan them.
107 */
108 void
109 exit1(struct thread *td, int rv)
110 {
111 struct proc *p, *nq, *q;
112 struct tty *tp;
113 struct vnode *ttyvp;
114 struct vnode *vtmp;
115 #ifdef KTRACE
116 struct vnode *tracevp;
117 struct ucred *tracecred;
118 #endif
119 struct plimit *plim;
120 int locked;
121
122 /*
123 * Drop Giant if caller has it. Eventually we should warn about
124 * being called with Giant held.
125 */
126 while (mtx_owned(&Giant))
127 mtx_unlock(&Giant);
128
129 p = td->td_proc;
130 if (p == initproc) {
131 printf("init died (signal %d, exit %d)\n",
132 WTERMSIG(rv), WEXITSTATUS(rv));
133 panic("Going nowhere without my init!");
134 }
135
136 /*
137 * MUST abort all other threads before proceeding past here.
138 */
139 PROC_LOCK(p);
140 if (p->p_flag & P_HADTHREADS) {
141 retry:
142 /*
143 * First check if some other thread got here before us..
144 * if so, act apropriatly, (exit or suspend);
145 */
146 thread_suspend_check(0);
147
148 /*
149 * Kill off the other threads. This requires
150 * some co-operation from other parts of the kernel
151 * so it may not be instantaneous. With this state set
152 * any thread entering the kernel from userspace will
153 * thread_exit() in trap(). Any thread attempting to
154 * sleep will return immediately with EINTR or EWOULDBLOCK
155 * which will hopefully force them to back out to userland
156 * freeing resources as they go. Any thread attempting
157 * to return to userland will thread_exit() from userret().
158 * thread_exit() will unsuspend us when the last of the
159 * other threads exits.
160 * If there is already a thread singler after resumption,
161 * calling thread_single will fail; in that case, we just
162 * re-check all suspension request, the thread should
163 * either be suspended there or exit.
164 */
165 if (thread_single(SINGLE_EXIT))
166 goto retry;
167
168 /*
169 * All other activity in this process is now stopped.
170 * Threading support has been turned off.
171 */
172 }
173
174 /*
175 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
176 * on our vmspace, so we should block below until they have
177 * released their reference to us. Note that if they have
178 * requested S_EXIT stops we will block here until they ack
179 * via PIOCCONT.
180 */
181 _STOPEVENT(p, S_EXIT, rv);
182
183 /*
184 * Note that we are exiting and do another wakeup of anyone in
185 * PIOCWAIT in case they aren't listening for S_EXIT stops or
186 * decided to wait again after we told them we are exiting.
187 */
188 p->p_flag |= P_WEXIT;
189 wakeup(&p->p_stype);
190
191 /*
192 * Wait for any processes that have a hold on our vmspace to
193 * release their reference.
194 */
195 while (p->p_lock > 0)
196 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
197 PROC_UNLOCK(p);
198
199 #ifdef AUDIT
200 /*
201 * The Sun BSM exit token contains two components: an exit status as
202 * passed to exit(), and a return value to indicate what sort of exit
203 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
204 * what the return value is.
205 */
206 AUDIT_ARG(exit, WEXITSTATUS(rv), 0);
207 AUDIT_SYSCALL_EXIT(0, td);
208 #endif
209
210 /* Are we a task leader? */
211 if (p == p->p_leader) {
212 mtx_lock(&ppeers_lock);
213 q = p->p_peers;
214 while (q != NULL) {
215 PROC_LOCK(q);
216 psignal(q, SIGKILL);
217 PROC_UNLOCK(q);
218 q = q->p_peers;
219 }
220 while (p->p_peers != NULL)
221 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
222 mtx_unlock(&ppeers_lock);
223 }
224
225 /*
226 * Check if any loadable modules need anything done at process exit.
227 * E.g. SYSV IPC stuff
228 * XXX what if one of these generates an error?
229 */
230 EVENTHANDLER_INVOKE(process_exit, p);
231
232 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
233 M_ZOMBIE, M_WAITOK);
234 /*
235 * If parent is waiting for us to exit or exec,
236 * P_PPWAIT is set; we will wakeup the parent below.
237 */
238 PROC_LOCK(p);
239 stopprofclock(p);
240 p->p_flag &= ~(P_TRACED | P_PPWAIT);
241 SIGEMPTYSET(p->p_siglist);
242 SIGEMPTYSET(td->td_siglist);
243
244 /*
245 * Stop the real interval timer. If the handler is currently
246 * executing, prevent it from rearming itself and let it finish.
247 */
248 if (timevalisset(&p->p_realtimer.it_value) &&
249 callout_stop(&p->p_itcallout) == 0) {
250 timevalclear(&p->p_realtimer.it_interval);
251 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
252 KASSERT(!timevalisset(&p->p_realtimer.it_value),
253 ("realtime timer is still armed"));
254 }
255 PROC_UNLOCK(p);
256
257 /*
258 * Reset any sigio structures pointing to us as a result of
259 * F_SETOWN with our pid.
260 */
261 funsetownlst(&p->p_sigiolst);
262
263 /*
264 * If this process has an nlminfo data area (for lockd), release it
265 */
266 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
267 (*nlminfo_release_p)(p);
268
269 /*
270 * Close open files and release open-file table.
271 * This may block!
272 */
273 fdfree(td);
274
275 /*
276 * If this thread tickled GEOM, we need to wait for the giggling to
277 * stop before we return to userland
278 */
279 if (td->td_pflags & TDP_GEOM)
280 g_waitidle();
281
282 /*
283 * Remove ourself from our leader's peer list and wake our leader.
284 */
285 mtx_lock(&ppeers_lock);
286 if (p->p_leader->p_peers) {
287 q = p->p_leader;
288 while (q->p_peers != p)
289 q = q->p_peers;
290 q->p_peers = p->p_peers;
291 wakeup(p->p_leader);
292 }
293 mtx_unlock(&ppeers_lock);
294
295 vmspace_exit(td);
296
297 mtx_lock(&Giant); /* XXX TTY */
298 sx_xlock(&proctree_lock);
299 if (SESS_LEADER(p)) {
300 struct session *sp;
301
302 sp = p->p_session;
303 if (sp->s_ttyvp) {
304 /*
305 * Controlling process.
306 * Signal foreground pgrp,
307 * drain controlling terminal
308 * and revoke access to controlling terminal.
309 */
310 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
311 tp = sp->s_ttyp;
312 if (sp->s_ttyp->t_pgrp) {
313 PGRP_LOCK(sp->s_ttyp->t_pgrp);
314 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
315 PGRP_UNLOCK(sp->s_ttyp->t_pgrp);
316 }
317 /* XXX tp should be locked. */
318 sx_xunlock(&proctree_lock);
319 (void) ttywait(tp);
320 sx_xlock(&proctree_lock);
321 /*
322 * The tty could have been revoked
323 * if we blocked.
324 */
325 if (sp->s_ttyvp) {
326 ttyvp = sp->s_ttyvp;
327 SESS_LOCK(p->p_session);
328 sp->s_ttyvp = NULL;
329 SESS_UNLOCK(p->p_session);
330 sx_xunlock(&proctree_lock);
331 VOP_LOCK(ttyvp, LK_EXCLUSIVE, td);
332 VOP_REVOKE(ttyvp, REVOKEALL);
333 vput(ttyvp);
334 sx_xlock(&proctree_lock);
335 }
336 }
337 if (sp->s_ttyvp) {
338 ttyvp = sp->s_ttyvp;
339 SESS_LOCK(p->p_session);
340 sp->s_ttyvp = NULL;
341 SESS_UNLOCK(p->p_session);
342 vrele(ttyvp);
343 }
344 /*
345 * s_ttyp is not zero'd; we use this to indicate
346 * that the session once had a controlling terminal.
347 * (for logging and informational purposes)
348 */
349 }
350 SESS_LOCK(p->p_session);
351 sp->s_leader = NULL;
352 SESS_UNLOCK(p->p_session);
353 }
354 fixjobc(p, p->p_pgrp, 0);
355 sx_xunlock(&proctree_lock);
356 (void)acct_process(td);
357 mtx_unlock(&Giant);
358 #ifdef KTRACE
359 /*
360 * Drain any pending records on the thread and release the trace
361 * file. It might be better if drain-and-clear were atomic.
362 */
363 ktrprocexit(td);
364 PROC_LOCK(p);
365 mtx_lock(&ktrace_mtx);
366 p->p_traceflag = 0; /* don't trace the vrele() */
367 tracevp = p->p_tracevp;
368 p->p_tracevp = NULL;
369 tracecred = p->p_tracecred;
370 p->p_tracecred = NULL;
371 mtx_unlock(&ktrace_mtx);
372 PROC_UNLOCK(p);
373 if (tracevp != NULL) {
374 locked = VFS_LOCK_GIANT(tracevp->v_mount);
375 vrele(tracevp);
376 VFS_UNLOCK_GIANT(locked);
377 }
378 if (tracecred != NULL)
379 crfree(tracecred);
380 #endif
381 /*
382 * Release reference to text vnode
383 */
384 if ((vtmp = p->p_textvp) != NULL) {
385 p->p_textvp = NULL;
386 locked = VFS_LOCK_GIANT(vtmp->v_mount);
387 vrele(vtmp);
388 VFS_UNLOCK_GIANT(locked);
389 }
390
391 /*
392 * Release our limits structure.
393 */
394 PROC_LOCK(p);
395 plim = p->p_limit;
396 p->p_limit = NULL;
397 PROC_UNLOCK(p);
398 lim_free(plim);
399
400 /*
401 * Remove proc from allproc queue and pidhash chain.
402 * Place onto zombproc. Unlink from parent's child list.
403 */
404 sx_xlock(&allproc_lock);
405 LIST_REMOVE(p, p_list);
406 LIST_INSERT_HEAD(&zombproc, p, p_list);
407 LIST_REMOVE(p, p_hash);
408 sx_xunlock(&allproc_lock);
409
410 sx_xlock(&proctree_lock);
411 q = LIST_FIRST(&p->p_children);
412 if (q != NULL) /* only need this if any child is S_ZOMB */
413 wakeup(initproc);
414 for (; q != NULL; q = nq) {
415 nq = LIST_NEXT(q, p_sibling);
416 PROC_LOCK(q);
417 proc_reparent(q, initproc);
418 q->p_sigparent = SIGCHLD;
419 /*
420 * Traced processes are killed
421 * since their existence means someone is screwing up.
422 */
423 if (q->p_flag & P_TRACED) {
424 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
425 psignal(q, SIGKILL);
426 }
427 PROC_UNLOCK(q);
428 }
429
430 /*
431 * Save exit status and finalize rusage info except for times,
432 * adding in child rusage info.
433 */
434 PROC_LOCK(p);
435 p->p_xstat = rv;
436 p->p_xthread = td;
437 p->p_stats->p_ru.ru_nvcsw++;
438 *p->p_ru = p->p_stats->p_ru;
439
440 /*
441 * Notify interested parties of our demise.
442 */
443 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT);
444
445 /*
446 * Just delete all entries in the p_klist. At this point we won't
447 * report any more events, and there are nasty race conditions that
448 * can beat us if we don't.
449 */
450 knlist_clear(&p->p_klist, 1);
451
452 /*
453 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
454 * flag set, or if the handler is set to SIG_IGN, notify process
455 * 1 instead (and hope it will handle this situation).
456 */
457 PROC_LOCK(p->p_pptr);
458 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
459 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
460 struct proc *pp;
461
462 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
463 pp = p->p_pptr;
464 PROC_UNLOCK(pp);
465 proc_reparent(p, initproc);
466 p->p_sigparent = SIGCHLD;
467 PROC_LOCK(p->p_pptr);
468 /*
469 * If this was the last child of our parent, notify
470 * parent, so in case he was wait(2)ing, he will
471 * continue.
472 */
473 if (LIST_EMPTY(&pp->p_children))
474 wakeup(pp);
475 } else
476 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
477
478 if (p->p_pptr == initproc)
479 psignal(p->p_pptr, SIGCHLD);
480 else if (p->p_sigparent != 0)
481 psignal(p->p_pptr, p->p_sigparent);
482 PROC_UNLOCK(p->p_pptr);
483
484 /*
485 * If this is a kthread, then wakeup anyone waiting for it to exit.
486 */
487 if (p->p_flag & P_KTHREAD)
488 wakeup(p);
489 PROC_UNLOCK(p);
490
491 /*
492 * Finally, call machine-dependent code to release the remaining
493 * resources including address space.
494 * The address space is released by "vmspace_exitfree(p)" in
495 * vm_waitproc().
496 */
497 cpu_exit(td);
498
499 WITNESS_WARN(WARN_PANIC, &proctree_lock.sx_object,
500 "process (pid %d) exiting", p->p_pid);
501
502 PROC_LOCK(p);
503 PROC_LOCK(p->p_pptr);
504 sx_xunlock(&proctree_lock);
505
506 /*
507 * We have to wait until after acquiring all locks before
508 * changing p_state. We need to avoid all possible context
509 * switches (including ones from blocking on a mutex) while
510 * marked as a zombie. We also have to set the zombie state
511 * before we release the parent process' proc lock to avoid
512 * a lost wakeup. So, we first call wakeup, then we grab the
513 * sched lock, update the state, and release the parent process'
514 * proc lock.
515 */
516 wakeup(p->p_pptr);
517 mtx_lock_spin(&sched_lock);
518 p->p_state = PRS_ZOMBIE;
519 PROC_UNLOCK(p->p_pptr);
520
521 sched_exit(p->p_pptr, td);
522
523 /*
524 * Hopefully no one will try to deliver a signal to the process this
525 * late in the game.
526 */
527 knlist_destroy(&p->p_klist);
528
529 /*
530 * Make sure the scheduler takes this thread out of its tables etc.
531 * This will also release this thread's reference to the ucred.
532 * Other thread parts to release include pcb bits and such.
533 */
534 thread_exit();
535 }
536
537 #ifdef COMPAT_43
538 /*
539 * The dirty work is handled by kern_wait().
540 *
541 * MPSAFE.
542 */
543 int
544 owait(struct thread *td, struct owait_args *uap __unused)
545 {
546 int error, status;
547
548 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
549 if (error == 0)
550 td->td_retval[1] = status;
551 return (error);
552 }
553 #endif /* COMPAT_43 */
554
555 /*
556 * The dirty work is handled by kern_wait().
557 *
558 * MPSAFE.
559 */
560 int
561 wait4(struct thread *td, struct wait_args *uap)
562 {
563 struct rusage ru, *rup;
564 int error, status;
565
566 if (uap->rusage != NULL)
567 rup = &ru;
568 else
569 rup = NULL;
570 error = kern_wait(td, uap->pid, &status, uap->options, rup);
571 if (uap->status != NULL && error == 0)
572 error = copyout(&status, uap->status, sizeof(status));
573 if (uap->rusage != NULL && error == 0)
574 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
575 return (error);
576 }
577
578 int
579 kern_wait(struct thread *td, pid_t pid, int *status, int options,
580 struct rusage *rusage)
581 {
582 struct proc *p, *q, *t;
583 int error, nfound;
584
585 AUDIT_ARG(pid, pid);
586
587 q = td->td_proc;
588 if (pid == 0) {
589 PROC_LOCK(q);
590 pid = -q->p_pgid;
591 PROC_UNLOCK(q);
592 }
593 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
594 return (EINVAL);
595 loop:
596 if (q->p_flag & P_STATCHILD) {
597 PROC_LOCK(q);
598 q->p_flag &= ~P_STATCHILD;
599 PROC_UNLOCK(q);
600 }
601 nfound = 0;
602 sx_xlock(&proctree_lock);
603 LIST_FOREACH(p, &q->p_children, p_sibling) {
604 PROC_LOCK(p);
605 if (pid != WAIT_ANY &&
606 p->p_pid != pid && p->p_pgid != -pid) {
607 PROC_UNLOCK(p);
608 continue;
609 }
610 if (p_canwait(td, p)) {
611 PROC_UNLOCK(p);
612 continue;
613 }
614
615 /*
616 * This special case handles a kthread spawned by linux_clone
617 * (see linux_misc.c). The linux_wait4 and linux_waitpid
618 * functions need to be able to distinguish between waiting
619 * on a process and waiting on a thread. It is a thread if
620 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
621 * signifies we want to wait for threads and not processes.
622 */
623 if ((p->p_sigparent != SIGCHLD) ^
624 ((options & WLINUXCLONE) != 0)) {
625 PROC_UNLOCK(p);
626 continue;
627 }
628
629 nfound++;
630 if (p->p_state == PRS_ZOMBIE) {
631
632 /*
633 * It is possible that the last thread of this
634 * process is still running on another CPU
635 * in thread_exit() after having dropped the process
636 * lock via PROC_UNLOCK() but before it has completed
637 * cpu_throw(). In that case, the other thread must
638 * still hold sched_lock, so simply by acquiring
639 * sched_lock once we will wait long enough for the
640 * thread to exit in that case.
641 */
642 mtx_lock_spin(&sched_lock);
643 mtx_unlock_spin(&sched_lock);
644
645 td->td_retval[0] = p->p_pid;
646 if (status)
647 *status = p->p_xstat; /* convert to int */
648 if (rusage) {
649 *rusage = *p->p_ru;
650 calcru(p, &rusage->ru_utime, &rusage->ru_stime);
651 }
652
653 /*
654 * If we got the child via a ptrace 'attach',
655 * we need to give it back to the old parent.
656 */
657 PROC_UNLOCK(p);
658 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
659 PROC_LOCK(p);
660 p->p_oppid = 0;
661 proc_reparent(p, t);
662 PROC_UNLOCK(p);
663 psignal(t, SIGCHLD);
664 wakeup(t);
665 PROC_UNLOCK(t);
666 sx_xunlock(&proctree_lock);
667 return (0);
668 }
669
670 /*
671 * Remove other references to this process to ensure
672 * we have an exclusive reference.
673 */
674 sx_xlock(&allproc_lock);
675 LIST_REMOVE(p, p_list); /* off zombproc */
676 sx_xunlock(&allproc_lock);
677 LIST_REMOVE(p, p_sibling);
678 leavepgrp(p);
679 sx_xunlock(&proctree_lock);
680
681 /*
682 * As a side effect of this lock, we know that
683 * all other writes to this proc are visible now, so
684 * no more locking is needed for p.
685 */
686 PROC_LOCK(p);
687 p->p_xstat = 0; /* XXX: why? */
688 PROC_UNLOCK(p);
689 PROC_LOCK(q);
690 ruadd(&q->p_stats->p_cru, &q->p_crux, p->p_ru,
691 &p->p_rux);
692 PROC_UNLOCK(q);
693 FREE(p->p_ru, M_ZOMBIE);
694 p->p_ru = NULL;
695
696 /*
697 * Decrement the count of procs running with this uid.
698 */
699 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
700
701 /*
702 * Free credentials, arguments, and sigacts.
703 */
704 crfree(p->p_ucred);
705 p->p_ucred = NULL;
706 pargs_drop(p->p_args);
707 p->p_args = NULL;
708 sigacts_free(p->p_sigacts);
709 p->p_sigacts = NULL;
710
711 /*
712 * Do any thread-system specific cleanups.
713 */
714 thread_wait(p);
715
716 /*
717 * Give vm and machine-dependent layer a chance
718 * to free anything that cpu_exit couldn't
719 * release while still running in process context.
720 */
721 vm_waitproc(p);
722 #ifdef MAC
723 mac_destroy_proc(p);
724 #endif
725 #ifdef AUDIT
726 audit_proc_free(p);
727 #endif
728 KASSERT(FIRST_THREAD_IN_PROC(p),
729 ("kern_wait: no residual thread!"));
730 uma_zfree(proc_zone, p);
731 sx_xlock(&allproc_lock);
732 nprocs--;
733 sx_xunlock(&allproc_lock);
734 return (0);
735 }
736 mtx_lock_spin(&sched_lock);
737 if ((p->p_flag & P_STOPPED_SIG) &&
738 (p->p_suspcount == p->p_numthreads) &&
739 (p->p_flag & P_WAITED) == 0 &&
740 (p->p_flag & P_TRACED || options & WUNTRACED)) {
741 mtx_unlock_spin(&sched_lock);
742 p->p_flag |= P_WAITED;
743 sx_xunlock(&proctree_lock);
744 td->td_retval[0] = p->p_pid;
745 if (status)
746 *status = W_STOPCODE(p->p_xstat);
747 PROC_UNLOCK(p);
748 return (0);
749 }
750 mtx_unlock_spin(&sched_lock);
751 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) {
752 sx_xunlock(&proctree_lock);
753 td->td_retval[0] = p->p_pid;
754 p->p_flag &= ~P_CONTINUED;
755 PROC_UNLOCK(p);
756
757 if (status)
758 *status = SIGCONT;
759 return (0);
760 }
761 PROC_UNLOCK(p);
762 }
763 if (nfound == 0) {
764 sx_xunlock(&proctree_lock);
765 return (ECHILD);
766 }
767 if (options & WNOHANG) {
768 sx_xunlock(&proctree_lock);
769 td->td_retval[0] = 0;
770 return (0);
771 }
772 PROC_LOCK(q);
773 sx_xunlock(&proctree_lock);
774 if (q->p_flag & P_STATCHILD) {
775 q->p_flag &= ~P_STATCHILD;
776 error = 0;
777 } else
778 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
779 PROC_UNLOCK(q);
780 if (error)
781 return (error);
782 goto loop;
783 }
784
785 /*
786 * Make process 'parent' the new parent of process 'child'.
787 * Must be called with an exclusive hold of proctree lock.
788 */
789 void
790 proc_reparent(struct proc *child, struct proc *parent)
791 {
792
793 sx_assert(&proctree_lock, SX_XLOCKED);
794 PROC_LOCK_ASSERT(child, MA_OWNED);
795 if (child->p_pptr == parent)
796 return;
797
798 LIST_REMOVE(child, p_sibling);
799 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
800 child->p_pptr = parent;
801 }
Cache object: 583ff9785c301952297326e3d5f1aa11
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