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/5.4/sys/kern/kern_exit.c 145648 2005-04-28 23:45:03Z davidxu $");
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/ptrace.h>
63 #include <sys/acct.h> /* for acct_process() function prototype */
64 #include <sys/filedesc.h>
65 #include <sys/mac.h>
66 #include <sys/shm.h>
67 #include <sys/sem.h>
68 #ifdef KTRACE
69 #include <sys/ktrace.h>
70 #endif
71
72 #include <vm/vm.h>
73 #include <vm/vm_extern.h>
74 #include <vm/vm_param.h>
75 #include <vm/pmap.h>
76 #include <vm/vm_map.h>
77 #include <vm/vm_page.h>
78 #include <vm/uma.h>
79
80 /* Required to be non-static for SysVR4 emulator */
81 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
82
83 /*
84 * exit --
85 * Death of process.
86 *
87 * MPSAFE
88 */
89 void
90 sys_exit(struct thread *td, struct sys_exit_args *uap)
91 {
92
93 exit1(td, W_EXITCODE(uap->rval, 0));
94 /* NOTREACHED */
95 }
96
97 /*
98 * Exit: deallocate address space and other resources, change proc state
99 * to zombie, and unlink proc from allproc and parent's lists. Save exit
100 * status and rusage for wait(). Check for child processes and orphan them.
101 */
102 void
103 exit1(struct thread *td, int rv)
104 {
105 struct bintime new_switchtime;
106 struct proc *p, *nq, *q;
107 struct tty *tp;
108 struct vnode *ttyvp;
109 struct vmspace *vm;
110 struct vnode *vtmp;
111 #ifdef KTRACE
112 struct vnode *tracevp;
113 struct ucred *tracecred;
114 #endif
115 struct plimit *plim;
116 int refcnt;
117
118 /*
119 * Drop Giant if caller has it. Eventually we should warn about
120 * being called with Giant held.
121 */
122 while (mtx_owned(&Giant))
123 mtx_unlock(&Giant);
124
125 p = td->td_proc;
126 if (p == initproc) {
127 printf("init died (signal %d, exit %d)\n",
128 WTERMSIG(rv), WEXITSTATUS(rv));
129 panic("Going nowhere without my init!");
130 }
131
132 /*
133 * MUST abort all other threads before proceeding past here.
134 */
135 PROC_LOCK(p);
136 if (p->p_flag & P_HADTHREADS) {
137 retry:
138 /*
139 * First check if some other thread got here before us..
140 * if so, act apropriatly, (exit or suspend);
141 */
142 thread_suspend_check(0);
143
144 /*
145 * Kill off the other threads. This requires
146 * Some co-operation from other parts of the kernel
147 * so it may not be instant.
148 * With this state set:
149 * Any thread entering the kernel from userspace will
150 * thread_exit() in trap(). Any thread attempting to
151 * sleep will return immediatly with EINTR or EWOULDBLOCK,
152 * which will hopefully force them to back out to userland,
153 * freeing resources as they go, and anything attempting
154 * to return to userland will thread_exit() from userret().
155 * thread_exit() will unsuspend us when the last other
156 * thread exits.
157 * If there is already a thread singler after resumption,
158 * calling thread_single will fail, in the case, we just
159 * re-check all suspension request, the thread should
160 * either be suspended there or exit.
161 */
162 if (thread_single(SINGLE_EXIT))
163 goto retry;
164 /*
165 * All other activity in this process is now stopped.
166 * Threading support has been turned off.
167 */
168 }
169
170 p->p_flag |= P_WEXIT;
171 PROC_UNLOCK(p);
172
173 /* Are we a task leader? */
174 if (p == p->p_leader) {
175 mtx_lock(&ppeers_lock);
176 q = p->p_peers;
177 while (q != NULL) {
178 PROC_LOCK(q);
179 psignal(q, SIGKILL);
180 PROC_UNLOCK(q);
181 q = q->p_peers;
182 }
183 while (p->p_peers != NULL)
184 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
185 mtx_unlock(&ppeers_lock);
186 }
187
188 PROC_LOCK(p);
189 _STOPEVENT(p, S_EXIT, rv);
190 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
191 PROC_UNLOCK(p);
192
193 /*
194 * Check if any loadable modules need anything done at process exit.
195 * e.g. SYSV IPC stuff
196 * XXX what if one of these generates an error?
197 */
198 EVENTHANDLER_INVOKE(process_exit, p);
199
200 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
201 M_ZOMBIE, M_WAITOK);
202 /*
203 * If parent is waiting for us to exit or exec,
204 * P_PPWAIT is set; we will wakeup the parent below.
205 */
206 PROC_LOCK(p);
207 stopprofclock(p);
208 p->p_flag &= ~(P_TRACED | P_PPWAIT);
209 SIGEMPTYSET(p->p_siglist);
210 SIGEMPTYSET(td->td_siglist);
211
212 /*
213 * Stop the real interval timer. If the handler is currently
214 * executing, prevent it from rearming itself and let it finish.
215 */
216 if (timevalisset(&p->p_realtimer.it_value) &&
217 callout_stop(&p->p_itcallout) == 0) {
218 timevalclear(&p->p_realtimer.it_interval);
219 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
220 KASSERT(!timevalisset(&p->p_realtimer.it_value),
221 ("realtime timer is still armed"));
222 }
223 PROC_UNLOCK(p);
224
225 /*
226 * Reset any sigio structures pointing to us as a result of
227 * F_SETOWN with our pid.
228 */
229 mtx_lock(&Giant); /* XXX: not sure if needed */
230 funsetownlst(&p->p_sigiolst);
231
232 /*
233 * Close open files and release open-file table.
234 * This may block!
235 */
236 fdfree(td);
237 mtx_unlock(&Giant);
238
239 /*
240 * If this thread tickled GEOM, we need to wait for the giggling to
241 * stop before we return to userland
242 */
243 if (td->td_pflags & TDP_GEOM)
244 g_waitidle();
245
246 /*
247 * Remove ourself from our leader's peer list and wake our leader.
248 */
249 mtx_lock(&ppeers_lock);
250 if (p->p_leader->p_peers) {
251 q = p->p_leader;
252 while (q->p_peers != p)
253 q = q->p_peers;
254 q->p_peers = p->p_peers;
255 wakeup(p->p_leader);
256 }
257 mtx_unlock(&ppeers_lock);
258
259 /* The next two chunks should probably be moved to vmspace_exit. */
260 vm = p->p_vmspace;
261 /*
262 * Release user portion of address space.
263 * This releases references to vnodes,
264 * which could cause I/O if the file has been unlinked.
265 * Need to do this early enough that we can still sleep.
266 * Can't free the entire vmspace as the kernel stack
267 * may be mapped within that space also.
268 *
269 * Processes sharing the same vmspace may exit in one order, and
270 * get cleaned up by vmspace_exit() in a different order. The
271 * last exiting process to reach this point releases as much of
272 * the environment as it can, and the last process cleaned up
273 * by vmspace_exit() (which decrements exitingcnt) cleans up the
274 * remainder.
275 */
276 atomic_add_int(&vm->vm_exitingcnt, 1);
277 do
278 refcnt = vm->vm_refcnt;
279 while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1));
280 if (refcnt == 1) {
281 shmexit(vm);
282 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map),
283 vm_map_max(&vm->vm_map));
284 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
285 vm_map_max(&vm->vm_map));
286 }
287
288 mtx_lock(&Giant);
289 sx_xlock(&proctree_lock);
290 if (SESS_LEADER(p)) {
291 struct session *sp;
292
293 sp = p->p_session;
294 if (sp->s_ttyvp) {
295 /*
296 * Controlling process.
297 * Signal foreground pgrp,
298 * drain controlling terminal
299 * and revoke access to controlling terminal.
300 */
301 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
302 tp = sp->s_ttyp;
303 if (sp->s_ttyp->t_pgrp) {
304 PGRP_LOCK(sp->s_ttyp->t_pgrp);
305 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
306 PGRP_UNLOCK(sp->s_ttyp->t_pgrp);
307 }
308 /* XXX tp should be locked. */
309 sx_xunlock(&proctree_lock);
310 (void) ttywait(tp);
311 sx_xlock(&proctree_lock);
312 /*
313 * The tty could have been revoked
314 * if we blocked.
315 */
316 if (sp->s_ttyvp) {
317 ttyvp = sp->s_ttyvp;
318 SESS_LOCK(p->p_session);
319 sp->s_ttyvp = NULL;
320 SESS_UNLOCK(p->p_session);
321 sx_xunlock(&proctree_lock);
322 VOP_REVOKE(ttyvp, REVOKEALL);
323 vrele(ttyvp);
324 sx_xlock(&proctree_lock);
325 }
326 }
327 if (sp->s_ttyvp) {
328 ttyvp = sp->s_ttyvp;
329 SESS_LOCK(p->p_session);
330 sp->s_ttyvp = NULL;
331 SESS_UNLOCK(p->p_session);
332 vrele(ttyvp);
333 }
334 /*
335 * s_ttyp is not zero'd; we use this to indicate
336 * that the session once had a controlling terminal.
337 * (for logging and informational purposes)
338 */
339 }
340 SESS_LOCK(p->p_session);
341 sp->s_leader = NULL;
342 SESS_UNLOCK(p->p_session);
343 }
344 fixjobc(p, p->p_pgrp, 0);
345 sx_xunlock(&proctree_lock);
346 (void)acct_process(td);
347 mtx_unlock(&Giant);
348 #ifdef KTRACE
349 /*
350 * release trace file
351 */
352 PROC_LOCK(p);
353 mtx_lock(&ktrace_mtx);
354 p->p_traceflag = 0; /* don't trace the vrele() */
355 tracevp = p->p_tracevp;
356 p->p_tracevp = NULL;
357 tracecred = p->p_tracecred;
358 p->p_tracecred = NULL;
359 mtx_unlock(&ktrace_mtx);
360 PROC_UNLOCK(p);
361 if (tracevp != NULL) {
362 mtx_lock(&Giant);
363 vrele(tracevp);
364 mtx_unlock(&Giant);
365 }
366 if (tracecred != NULL)
367 crfree(tracecred);
368 #endif
369 /*
370 * Release reference to text vnode
371 */
372 if ((vtmp = p->p_textvp) != NULL) {
373 p->p_textvp = NULL;
374 mtx_lock(&Giant);
375 vrele(vtmp);
376 mtx_unlock(&Giant);
377 }
378
379 /*
380 * Release our limits structure.
381 */
382 PROC_LOCK(p);
383 plim = p->p_limit;
384 p->p_limit = NULL;
385 PROC_UNLOCK(p);
386 lim_free(plim);
387
388 /*
389 * Remove proc from allproc queue and pidhash chain.
390 * Place onto zombproc. Unlink from parent's child list.
391 */
392 sx_xlock(&allproc_lock);
393 LIST_REMOVE(p, p_list);
394 LIST_INSERT_HEAD(&zombproc, p, p_list);
395 LIST_REMOVE(p, p_hash);
396 sx_xunlock(&allproc_lock);
397
398 sx_xlock(&proctree_lock);
399 q = LIST_FIRST(&p->p_children);
400 if (q != NULL) /* only need this if any child is S_ZOMB */
401 wakeup(initproc);
402 for (; q != NULL; q = nq) {
403 nq = LIST_NEXT(q, p_sibling);
404 PROC_LOCK(q);
405 proc_reparent(q, initproc);
406 q->p_sigparent = SIGCHLD;
407 /*
408 * Traced processes are killed
409 * since their existence means someone is screwing up.
410 */
411 if (q->p_flag & P_TRACED) {
412 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
413 psignal(q, SIGKILL);
414 }
415 PROC_UNLOCK(q);
416 }
417
418 /*
419 * Save exit status and final rusage info, adding in child rusage
420 * info and self times.
421 */
422 mtx_lock(&Giant);
423 PROC_LOCK(p);
424 p->p_xstat = rv;
425 p->p_xthread = td;
426 *p->p_ru = p->p_stats->p_ru;
427 mtx_lock_spin(&sched_lock);
428 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
429 mtx_unlock_spin(&sched_lock);
430 ruadd(p->p_ru, &p->p_stats->p_cru);
431
432 mtx_unlock(&Giant);
433 /*
434 * Notify interested parties of our demise.
435 */
436 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT);
437 /*
438 * Just delete all entries in the p_klist. At this point we won't
439 * report any more events, and there are nasty race conditions that
440 * can beat us if we don't.
441 */
442 knlist_clear(&p->p_klist, 1);
443
444 /*
445 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
446 * flag set, or if the handler is set to SIG_IGN, notify process
447 * 1 instead (and hope it will handle this situation).
448 */
449 PROC_LOCK(p->p_pptr);
450 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
451 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
452 struct proc *pp;
453
454 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
455 pp = p->p_pptr;
456 PROC_UNLOCK(pp);
457 proc_reparent(p, initproc);
458 p->p_sigparent = SIGCHLD;
459 PROC_LOCK(p->p_pptr);
460 /*
461 * If this was the last child of our parent, notify
462 * parent, so in case he was wait(2)ing, he will
463 * continue.
464 */
465 if (LIST_EMPTY(&pp->p_children))
466 wakeup(pp);
467 } else
468 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
469
470 if (p->p_pptr == initproc)
471 psignal(p->p_pptr, SIGCHLD);
472 else if (p->p_sigparent != 0)
473 psignal(p->p_pptr, p->p_sigparent);
474 PROC_UNLOCK(p->p_pptr);
475
476 /*
477 * If this is a kthread, then wakeup anyone waiting for it to exit.
478 */
479 if (p->p_flag & P_KTHREAD)
480 wakeup(p);
481 PROC_UNLOCK(p);
482
483 /*
484 * Finally, call machine-dependent code to release the remaining
485 * resources including address space.
486 * The address space is released by "vmspace_exitfree(p)" in
487 * vm_waitproc().
488 */
489 cpu_exit(td);
490
491 PROC_LOCK(p);
492 PROC_LOCK(p->p_pptr);
493 sx_xunlock(&proctree_lock);
494
495 while (mtx_owned(&Giant))
496 mtx_unlock(&Giant);
497
498 /*
499 * We have to wait until after acquiring all locks before
500 * changing p_state. We need to avoid any possibly context
501 * switches while marked as a zombie including blocking on
502 * a mutex.
503 */
504 mtx_lock_spin(&sched_lock);
505 p->p_state = PRS_ZOMBIE;
506 critical_enter();
507 mtx_unlock_spin(&sched_lock);
508
509 wakeup(p->p_pptr);
510 /*
511 * XXX hack, swap in parent process, please see TDP_WAKEPROC0
512 * code, because TDP_WAKEPROC0 is only useful if thread is
513 * leaving critical region, but here we never leave and
514 * thread_exit() will call cpu_throw(), TDP_WAKEPROC0 is never
515 * cleared.
516 */
517 if (p->p_pptr->p_sflag & PS_SWAPINREQ)
518 wakeup(&proc0);
519 PROC_UNLOCK(p->p_pptr);
520
521 mtx_lock_spin(&sched_lock);
522 critical_exit();
523
524 /* Do the same timestamp bookkeeping that mi_switch() would do. */
525 binuptime(&new_switchtime);
526 bintime_add(&p->p_runtime, &new_switchtime);
527 bintime_sub(&p->p_runtime, PCPU_PTR(switchtime));
528 PCPU_SET(switchtime, new_switchtime);
529 PCPU_SET(switchticks, ticks);
530
531 cnt.v_swtch++;
532 sched_exit(p->p_pptr, td);
533
534 /*
535 * hopefully no one will try to deliver a signal to the process this
536 * late in the game.
537 */
538 knlist_destroy(&p->p_klist);
539
540 /*
541 * Make sure the scheduler takes this thread out of its tables etc.
542 * This will also release this thread's reference to the ucred.
543 * Other thread parts to release include pcb bits and such.
544 */
545 thread_exit();
546 }
547
548 #ifdef COMPAT_43
549 /*
550 * MPSAFE. The dirty work is handled by kern_wait().
551 */
552 int
553 owait(struct thread *td, struct owait_args *uap __unused)
554 {
555 int error, status;
556
557 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
558 if (error == 0)
559 td->td_retval[1] = status;
560 return (error);
561 }
562 #endif /* COMPAT_43 */
563
564 /*
565 * MPSAFE. The dirty work is handled by kern_wait().
566 */
567 int
568 wait4(struct thread *td, struct wait_args *uap)
569 {
570 struct rusage ru;
571 int error, status;
572
573 error = kern_wait(td, uap->pid, &status, uap->options, &ru);
574 if (uap->status != NULL && error == 0)
575 error = copyout(&status, uap->status, sizeof(status));
576 if (uap->rusage != NULL && error == 0)
577 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
578 return (error);
579 }
580
581 int
582 kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage)
583 {
584 int nfound;
585 struct proc *p, *q, *t;
586 int error;
587
588 q = td->td_proc;
589 if (pid == 0) {
590 PROC_LOCK(q);
591 pid = -q->p_pgid;
592 PROC_UNLOCK(q);
593 }
594 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
595 return (EINVAL);
596 loop:
597 if (q->p_flag & P_STATCHILD) {
598 PROC_LOCK(q);
599 q->p_flag &= ~P_STATCHILD;
600 PROC_UNLOCK(q);
601 }
602 nfound = 0;
603 sx_xlock(&proctree_lock);
604 LIST_FOREACH(p, &q->p_children, p_sibling) {
605 PROC_LOCK(p);
606 if (pid != WAIT_ANY &&
607 p->p_pid != pid && p->p_pgid != -pid) {
608 PROC_UNLOCK(p);
609 continue;
610 }
611
612 /*
613 * This special case handles a kthread spawned by linux_clone
614 * (see linux_misc.c). The linux_wait4 and linux_waitpid
615 * functions need to be able to distinguish between waiting
616 * on a process and waiting on a thread. It is a thread if
617 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
618 * signifies we want to wait for threads and not processes.
619 */
620 if ((p->p_sigparent != SIGCHLD) ^
621 ((options & WLINUXCLONE) != 0)) {
622 PROC_UNLOCK(p);
623 continue;
624 }
625
626 nfound++;
627 if (p->p_state == PRS_ZOMBIE) {
628 td->td_retval[0] = p->p_pid;
629 if (status)
630 *status = p->p_xstat; /* convert to int */
631 if (rusage)
632 *rusage = *p->p_ru;
633
634 /*
635 * If we got the child via a ptrace 'attach',
636 * we need to give it back to the old parent.
637 */
638 PROC_UNLOCK(p);
639 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
640 PROC_LOCK(p);
641 p->p_oppid = 0;
642 proc_reparent(p, t);
643 PROC_UNLOCK(p);
644 psignal(t, SIGCHLD);
645 wakeup(t);
646 PROC_UNLOCK(t);
647 sx_xunlock(&proctree_lock);
648 return (0);
649 }
650
651 /*
652 * Remove other references to this process to ensure
653 * we have an exclusive reference.
654 */
655 sx_xlock(&allproc_lock);
656 LIST_REMOVE(p, p_list); /* off zombproc */
657 sx_xunlock(&allproc_lock);
658 LIST_REMOVE(p, p_sibling);
659 leavepgrp(p);
660 sx_xunlock(&proctree_lock);
661
662 /*
663 * As a side effect of this lock, we know that
664 * all other writes to this proc are visible now, so
665 * no more locking is needed for p.
666 */
667 mtx_lock(&Giant);
668 PROC_LOCK(p);
669 p->p_xstat = 0; /* XXX: why? */
670 PROC_UNLOCK(p);
671 PROC_LOCK(q);
672 ruadd(&q->p_stats->p_cru, p->p_ru);
673 PROC_UNLOCK(q);
674 FREE(p->p_ru, M_ZOMBIE);
675 p->p_ru = NULL;
676 mtx_unlock(&Giant);
677
678 /*
679 * Decrement the count of procs running with this uid.
680 */
681 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
682
683 /*
684 * Free credentials, arguments, and sigacts
685 */
686 crfree(p->p_ucred);
687 p->p_ucred = NULL;
688 pargs_drop(p->p_args);
689 p->p_args = NULL;
690 sigacts_free(p->p_sigacts);
691 p->p_sigacts = NULL;
692
693 /*
694 * do any thread-system specific cleanups
695 */
696 thread_wait(p);
697
698 /*
699 * Give vm and machine-dependent layer a chance
700 * to free anything that cpu_exit couldn't
701 * release while still running in process context.
702 */
703 vm_waitproc(p);
704 #ifdef MAC
705 mac_destroy_proc(p);
706 #endif
707 KASSERT(FIRST_THREAD_IN_PROC(p),
708 ("kern_wait: no residual thread!"));
709 uma_zfree(proc_zone, p);
710 sx_xlock(&allproc_lock);
711 nprocs--;
712 sx_xunlock(&allproc_lock);
713 return (0);
714 }
715 mtx_lock_spin(&sched_lock);
716 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) &&
717 ((p->p_flag & P_WAITED) == 0) &&
718 (p->p_flag & P_TRACED || options & WUNTRACED)) {
719 mtx_unlock_spin(&sched_lock);
720 p->p_flag |= P_WAITED;
721 sx_xunlock(&proctree_lock);
722 td->td_retval[0] = p->p_pid;
723 if (status)
724 *status = W_STOPCODE(p->p_xstat);
725 PROC_UNLOCK(p);
726 return (0);
727 }
728 mtx_unlock_spin(&sched_lock);
729 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) {
730 sx_xunlock(&proctree_lock);
731 td->td_retval[0] = p->p_pid;
732 p->p_flag &= ~P_CONTINUED;
733 PROC_UNLOCK(p);
734
735 if (status)
736 *status = SIGCONT;
737 return (0);
738 }
739 PROC_UNLOCK(p);
740 }
741 if (nfound == 0) {
742 sx_xunlock(&proctree_lock);
743 return (ECHILD);
744 }
745 if (options & WNOHANG) {
746 sx_xunlock(&proctree_lock);
747 td->td_retval[0] = 0;
748 return (0);
749 }
750 PROC_LOCK(q);
751 sx_xunlock(&proctree_lock);
752 if (q->p_flag & P_STATCHILD) {
753 q->p_flag &= ~P_STATCHILD;
754 error = 0;
755 } else
756 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
757 PROC_UNLOCK(q);
758 if (error)
759 return (error);
760 goto loop;
761 }
762
763 /*
764 * Make process 'parent' the new parent of process 'child'.
765 * Must be called with an exclusive hold of proctree lock.
766 */
767 void
768 proc_reparent(struct proc *child, struct proc *parent)
769 {
770
771 sx_assert(&proctree_lock, SX_XLOCKED);
772 PROC_LOCK_ASSERT(child, MA_OWNED);
773 if (child->p_pptr == parent)
774 return;
775
776 LIST_REMOVE(child, p_sibling);
777 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
778 child->p_pptr = parent;
779 }
Cache object: 42a1349f92c8a360d05addcc3a626333
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