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/6.4/sys/kern/kern_exit.c 169657 2007-05-17 13:52:37Z jhb $");
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 /*
411 * Call machine-dependent code to release any
412 * machine-dependent resources other than the address space.
413 * The address space is released by "vmspace_exitfree(p)" in
414 * vm_waitproc().
415 */
416 cpu_exit(td);
417
418 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
419
420 sx_xlock(&proctree_lock);
421 q = LIST_FIRST(&p->p_children);
422 if (q != NULL) /* only need this if any child is S_ZOMB */
423 wakeup(initproc);
424 for (; q != NULL; q = nq) {
425 nq = LIST_NEXT(q, p_sibling);
426 PROC_LOCK(q);
427 proc_reparent(q, initproc);
428 q->p_sigparent = SIGCHLD;
429 /*
430 * Traced processes are killed
431 * since their existence means someone is screwing up.
432 */
433 if (q->p_flag & P_TRACED) {
434 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
435 psignal(q, SIGKILL);
436 }
437 PROC_UNLOCK(q);
438 }
439
440 /*
441 * Save exit status and finalize rusage info except for times,
442 * adding in child rusage info.
443 */
444 PROC_LOCK(p);
445 p->p_xstat = rv;
446 p->p_xthread = td;
447 p->p_stats->p_ru.ru_nvcsw++;
448 *p->p_ru = p->p_stats->p_ru;
449
450 /*
451 * Notify interested parties of our demise.
452 */
453 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT);
454
455 /*
456 * Just delete all entries in the p_klist. At this point we won't
457 * report any more events, and there are nasty race conditions that
458 * can beat us if we don't.
459 */
460 knlist_clear(&p->p_klist, 1);
461
462 /*
463 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
464 * flag set, or if the handler is set to SIG_IGN, notify process
465 * 1 instead (and hope it will handle this situation).
466 */
467 PROC_LOCK(p->p_pptr);
468 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
469 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
470 struct proc *pp;
471
472 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
473 pp = p->p_pptr;
474 PROC_UNLOCK(pp);
475 proc_reparent(p, initproc);
476 p->p_sigparent = SIGCHLD;
477 PROC_LOCK(p->p_pptr);
478 /*
479 * If this was the last child of our parent, notify
480 * parent, so in case he was wait(2)ing, he will
481 * continue.
482 */
483 if (LIST_EMPTY(&pp->p_children))
484 wakeup(pp);
485 } else
486 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
487
488 if (p->p_pptr == initproc)
489 psignal(p->p_pptr, SIGCHLD);
490 else if (p->p_sigparent != 0)
491 psignal(p->p_pptr, p->p_sigparent);
492 sx_xunlock(&proctree_lock);
493
494 /*
495 * If this is a kthread, then wakeup anyone waiting for it to exit.
496 */
497 if (p->p_flag & P_KTHREAD)
498 wakeup(p);
499
500 /*
501 * We have to wait until after acquiring all locks before
502 * changing p_state. We need to avoid all possible context
503 * switches (including ones from blocking on a mutex) while
504 * marked as a zombie. We also have to set the zombie state
505 * before we release the parent process' proc lock to avoid
506 * a lost wakeup. So, we first call wakeup, then we grab the
507 * sched lock, update the state, and release the parent process'
508 * proc lock.
509 */
510 wakeup(p->p_pptr);
511 mtx_lock_spin(&sched_lock);
512 p->p_state = PRS_ZOMBIE;
513 PROC_UNLOCK(p->p_pptr);
514
515 sched_exit(p->p_pptr, td);
516
517 /*
518 * Hopefully no one will try to deliver a signal to the process this
519 * late in the game.
520 */
521 knlist_destroy(&p->p_klist);
522
523 /*
524 * Make sure the scheduler takes this thread out of its tables etc.
525 * This will also release this thread's reference to the ucred.
526 * Other thread parts to release include pcb bits and such.
527 */
528 thread_exit();
529 }
530
531 #ifdef COMPAT_43
532 /*
533 * The dirty work is handled by kern_wait().
534 *
535 * MPSAFE.
536 */
537 int
538 owait(struct thread *td, struct owait_args *uap __unused)
539 {
540 int error, status;
541
542 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
543 if (error == 0)
544 td->td_retval[1] = status;
545 return (error);
546 }
547 #endif /* COMPAT_43 */
548
549 /*
550 * The dirty work is handled by kern_wait().
551 *
552 * MPSAFE.
553 */
554 int
555 wait4(struct thread *td, struct wait_args *uap)
556 {
557 struct rusage ru, *rup;
558 int error, status;
559
560 if (uap->rusage != NULL)
561 rup = &ru;
562 else
563 rup = NULL;
564 error = kern_wait(td, uap->pid, &status, uap->options, rup);
565 if (uap->status != NULL && error == 0)
566 error = copyout(&status, uap->status, sizeof(status));
567 if (uap->rusage != NULL && error == 0)
568 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
569 return (error);
570 }
571
572 int
573 kern_wait(struct thread *td, pid_t pid, int *status, int options,
574 struct rusage *rusage)
575 {
576 struct proc *p, *q, *t;
577 int error, nfound;
578
579 AUDIT_ARG(pid, pid);
580
581 q = td->td_proc;
582 if (pid == 0) {
583 PROC_LOCK(q);
584 pid = -q->p_pgid;
585 PROC_UNLOCK(q);
586 }
587 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
588 return (EINVAL);
589 loop:
590 if (q->p_flag & P_STATCHILD) {
591 PROC_LOCK(q);
592 q->p_flag &= ~P_STATCHILD;
593 PROC_UNLOCK(q);
594 }
595 nfound = 0;
596 sx_xlock(&proctree_lock);
597 LIST_FOREACH(p, &q->p_children, p_sibling) {
598 PROC_LOCK(p);
599 if (pid != WAIT_ANY &&
600 p->p_pid != pid && p->p_pgid != -pid) {
601 PROC_UNLOCK(p);
602 continue;
603 }
604 if (p_canwait(td, p)) {
605 PROC_UNLOCK(p);
606 continue;
607 }
608
609 /*
610 * This special case handles a kthread spawned by linux_clone
611 * (see linux_misc.c). The linux_wait4 and linux_waitpid
612 * functions need to be able to distinguish between waiting
613 * on a process and waiting on a thread. It is a thread if
614 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
615 * signifies we want to wait for threads and not processes.
616 */
617 if ((p->p_sigparent != SIGCHLD) ^
618 ((options & WLINUXCLONE) != 0)) {
619 PROC_UNLOCK(p);
620 continue;
621 }
622
623 nfound++;
624 if (p->p_state == PRS_ZOMBIE) {
625
626 /*
627 * It is possible that the last thread of this
628 * process is still running on another CPU
629 * in thread_exit() after having dropped the process
630 * lock via PROC_UNLOCK() but before it has completed
631 * cpu_throw(). In that case, the other thread must
632 * still hold sched_lock, so simply by acquiring
633 * sched_lock once we will wait long enough for the
634 * thread to exit in that case.
635 */
636 mtx_lock_spin(&sched_lock);
637 mtx_unlock_spin(&sched_lock);
638
639 td->td_retval[0] = p->p_pid;
640 if (status)
641 *status = p->p_xstat; /* convert to int */
642 if (rusage) {
643 *rusage = *p->p_ru;
644 calcru(p, &rusage->ru_utime, &rusage->ru_stime);
645 }
646
647 /*
648 * If we got the child via a ptrace 'attach',
649 * we need to give it back to the old parent.
650 */
651 PROC_UNLOCK(p);
652 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
653 PROC_LOCK(p);
654 p->p_oppid = 0;
655 proc_reparent(p, t);
656 PROC_UNLOCK(p);
657 psignal(t, SIGCHLD);
658 wakeup(t);
659 PROC_UNLOCK(t);
660 sx_xunlock(&proctree_lock);
661 return (0);
662 }
663
664 /*
665 * Remove other references to this process to ensure
666 * we have an exclusive reference.
667 */
668 sx_xlock(&allproc_lock);
669 LIST_REMOVE(p, p_list); /* off zombproc */
670 sx_xunlock(&allproc_lock);
671 LIST_REMOVE(p, p_sibling);
672 leavepgrp(p);
673 sx_xunlock(&proctree_lock);
674
675 /*
676 * As a side effect of this lock, we know that
677 * all other writes to this proc are visible now, so
678 * no more locking is needed for p.
679 */
680 PROC_LOCK(p);
681 p->p_xstat = 0; /* XXX: why? */
682 PROC_UNLOCK(p);
683 PROC_LOCK(q);
684 ruadd(&q->p_stats->p_cru, &q->p_crux, p->p_ru,
685 &p->p_rux);
686 PROC_UNLOCK(q);
687 FREE(p->p_ru, M_ZOMBIE);
688 p->p_ru = NULL;
689
690 /*
691 * Decrement the count of procs running with this uid.
692 */
693 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
694
695 /*
696 * Free credentials, arguments, and sigacts.
697 */
698 crfree(p->p_ucred);
699 p->p_ucred = NULL;
700 pargs_drop(p->p_args);
701 p->p_args = NULL;
702 sigacts_free(p->p_sigacts);
703 p->p_sigacts = NULL;
704
705 /*
706 * Do any thread-system specific cleanups.
707 */
708 thread_wait(p);
709
710 /*
711 * Give vm and machine-dependent layer a chance
712 * to free anything that cpu_exit couldn't
713 * release while still running in process context.
714 */
715 vm_waitproc(p);
716 #ifdef MAC
717 mac_destroy_proc(p);
718 #endif
719 #ifdef AUDIT
720 audit_proc_free(p);
721 #endif
722 KASSERT(FIRST_THREAD_IN_PROC(p),
723 ("kern_wait: no residual thread!"));
724 uma_zfree(proc_zone, p);
725 sx_xlock(&allproc_lock);
726 nprocs--;
727 sx_xunlock(&allproc_lock);
728 return (0);
729 }
730 mtx_lock_spin(&sched_lock);
731 if ((p->p_flag & P_STOPPED_SIG) &&
732 (p->p_suspcount == p->p_numthreads) &&
733 (p->p_flag & P_WAITED) == 0 &&
734 (p->p_flag & P_TRACED || options & WUNTRACED)) {
735 mtx_unlock_spin(&sched_lock);
736 p->p_flag |= P_WAITED;
737 sx_xunlock(&proctree_lock);
738 td->td_retval[0] = p->p_pid;
739 if (status)
740 *status = W_STOPCODE(p->p_xstat);
741 PROC_UNLOCK(p);
742 return (0);
743 }
744 mtx_unlock_spin(&sched_lock);
745 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) {
746 sx_xunlock(&proctree_lock);
747 td->td_retval[0] = p->p_pid;
748 p->p_flag &= ~P_CONTINUED;
749 PROC_UNLOCK(p);
750
751 if (status)
752 *status = SIGCONT;
753 return (0);
754 }
755 PROC_UNLOCK(p);
756 }
757 if (nfound == 0) {
758 sx_xunlock(&proctree_lock);
759 return (ECHILD);
760 }
761 if (options & WNOHANG) {
762 sx_xunlock(&proctree_lock);
763 td->td_retval[0] = 0;
764 return (0);
765 }
766 PROC_LOCK(q);
767 sx_xunlock(&proctree_lock);
768 if (q->p_flag & P_STATCHILD) {
769 q->p_flag &= ~P_STATCHILD;
770 error = 0;
771 } else
772 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
773 PROC_UNLOCK(q);
774 if (error)
775 return (error);
776 goto loop;
777 }
778
779 /*
780 * Make process 'parent' the new parent of process 'child'.
781 * Must be called with an exclusive hold of proctree lock.
782 */
783 void
784 proc_reparent(struct proc *child, struct proc *parent)
785 {
786
787 sx_assert(&proctree_lock, SX_XLOCKED);
788 PROC_LOCK_ASSERT(child, MA_OWNED);
789 if (child->p_pptr == parent)
790 return;
791
792 LIST_REMOVE(child, p_sibling);
793 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
794 child->p_pptr = parent;
795 }
Cache object: 239d73b435b43329a65df713e13ba28e
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