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("$FreeBSD$");
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 <vm/vm.h>
74 #include <vm/vm_extern.h>
75 #include <vm/vm_param.h>
76 #include <vm/pmap.h>
77 #include <vm/vm_map.h>
78 #include <vm/vm_page.h>
79 #include <vm/uma.h>
80
81 /* Required to be non-static for SysVR4 emulator */
82 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
83
84 /*
85 * exit --
86 * Death of process.
87 *
88 * MPSAFE
89 */
90 void
91 sys_exit(struct thread *td, struct sys_exit_args *uap)
92 {
93
94 exit1(td, W_EXITCODE(uap->rval, 0));
95 /* NOTREACHED */
96 }
97
98 /*
99 * Exit: deallocate address space and other resources, change proc state
100 * to zombie, and unlink proc from allproc and parent's lists. Save exit
101 * status and rusage for wait(). Check for child processes and orphan them.
102 */
103 void
104 exit1(struct thread *td, int rv)
105 {
106 struct bintime new_switchtime;
107 struct proc *p, *nq, *q;
108 struct tty *tp;
109 struct vnode *ttyvp;
110 struct vmspace *vm;
111 struct vnode *vtmp;
112 #ifdef KTRACE
113 struct vnode *tracevp;
114 struct ucred *tracecred;
115 #endif
116 struct plimit *plim;
117 int refcnt;
118
119 /*
120 * Drop Giant if caller has it. Eventually we should warn about
121 * being called with Giant held.
122 */
123 while (mtx_owned(&Giant))
124 mtx_unlock(&Giant);
125
126 p = td->td_proc;
127 if (p == initproc) {
128 printf("init died (signal %d, exit %d)\n",
129 WTERMSIG(rv), WEXITSTATUS(rv));
130 panic("Going nowhere without my init!");
131 }
132
133 /*
134 * MUST abort all other threads before proceeding past here.
135 */
136 PROC_LOCK(p);
137 if (p->p_flag & P_HADTHREADS) {
138 retry:
139 /*
140 * First check if some other thread got here before us..
141 * if so, act apropriatly, (exit or suspend);
142 */
143 thread_suspend_check(0);
144
145 /*
146 * Kill off the other threads. This requires
147 * Some co-operation from other parts of the kernel
148 * so it may not be instant.
149 * With this state set:
150 * Any thread entering the kernel from userspace will
151 * thread_exit() in trap(). Any thread attempting to
152 * sleep will return immediatly with EINTR or EWOULDBLOCK,
153 * which will hopefully force them to back out to userland,
154 * freeing resources as they go, and anything attempting
155 * to return to userland will thread_exit() from userret().
156 * thread_exit() will unsuspend us when the last other
157 * thread exits.
158 * If there is already a thread singler after resumption,
159 * calling thread_single will fail, in the case, we just
160 * re-check all suspension request, the thread should
161 * either be suspended there or exit.
162 */
163 if (thread_single(SINGLE_EXIT))
164 goto retry;
165 /*
166 * All other activity in this process is now stopped.
167 * Threading support has been turned off.
168 */
169 }
170
171 p->p_flag |= P_WEXIT;
172 PROC_UNLOCK(p);
173
174 /* Are we a task leader? */
175 if (p == p->p_leader) {
176 mtx_lock(&ppeers_lock);
177 q = p->p_peers;
178 while (q != NULL) {
179 PROC_LOCK(q);
180 psignal(q, SIGKILL);
181 PROC_UNLOCK(q);
182 q = q->p_peers;
183 }
184 while (p->p_peers != NULL)
185 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
186 mtx_unlock(&ppeers_lock);
187 }
188
189 PROC_LOCK(p);
190 _STOPEVENT(p, S_EXIT, rv);
191 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
192 PROC_UNLOCK(p);
193
194 /*
195 * Check if any loadable modules need anything done at process exit.
196 * e.g. SYSV IPC stuff
197 * XXX what if one of these generates an error?
198 */
199 EVENTHANDLER_INVOKE(process_exit, p);
200
201 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
202 M_ZOMBIE, M_WAITOK);
203 /*
204 * If parent is waiting for us to exit or exec,
205 * P_PPWAIT is set; we will wakeup the parent below.
206 */
207 PROC_LOCK(p);
208 stopprofclock(p);
209 p->p_flag &= ~(P_TRACED | P_PPWAIT);
210 SIGEMPTYSET(p->p_siglist);
211 SIGEMPTYSET(td->td_siglist);
212
213 /*
214 * Stop the real interval timer. If the handler is currently
215 * executing, prevent it from rearming itself and let it finish.
216 */
217 if (timevalisset(&p->p_realtimer.it_value) &&
218 callout_stop(&p->p_itcallout) == 0) {
219 timevalclear(&p->p_realtimer.it_interval);
220 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
221 KASSERT(!timevalisset(&p->p_realtimer.it_value),
222 ("realtime timer is still armed"));
223 }
224 PROC_UNLOCK(p);
225
226 /*
227 * Reset any sigio structures pointing to us as a result of
228 * F_SETOWN with our pid.
229 */
230 mtx_lock(&Giant); /* XXX: not sure if needed */
231 funsetownlst(&p->p_sigiolst);
232
233 /*
234 * Close open files and release open-file table.
235 * This may block!
236 */
237 fdfree(td);
238 mtx_unlock(&Giant);
239
240 /*
241 * If this thread tickled GEOM, we need to wait for the giggling to
242 * stop before we return to userland
243 */
244 if (td->td_pflags & TDP_GEOM)
245 g_waitidle();
246
247 /*
248 * Remove ourself from our leader's peer list and wake our leader.
249 */
250 mtx_lock(&ppeers_lock);
251 if (p->p_leader->p_peers) {
252 q = p->p_leader;
253 while (q->p_peers != p)
254 q = q->p_peers;
255 q->p_peers = p->p_peers;
256 wakeup(p->p_leader);
257 }
258 mtx_unlock(&ppeers_lock);
259
260 /* The next two chunks should probably be moved to vmspace_exit. */
261 vm = p->p_vmspace;
262 /*
263 * Release user portion of address space.
264 * This releases references to vnodes,
265 * which could cause I/O if the file has been unlinked.
266 * Need to do this early enough that we can still sleep.
267 * Can't free the entire vmspace as the kernel stack
268 * may be mapped within that space also.
269 *
270 * Processes sharing the same vmspace may exit in one order, and
271 * get cleaned up by vmspace_exit() in a different order. The
272 * last exiting process to reach this point releases as much of
273 * the environment as it can, and the last process cleaned up
274 * by vmspace_exit() (which decrements exitingcnt) cleans up the
275 * remainder.
276 */
277 atomic_add_int(&vm->vm_exitingcnt, 1);
278 do
279 refcnt = vm->vm_refcnt;
280 while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1));
281 if (refcnt == 1) {
282 shmexit(vm);
283 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map),
284 vm_map_max(&vm->vm_map));
285 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
286 vm_map_max(&vm->vm_map));
287 }
288
289 mtx_lock(&Giant);
290 sx_xlock(&proctree_lock);
291 if (SESS_LEADER(p)) {
292 struct session *sp;
293
294 sp = p->p_session;
295 if (sp->s_ttyvp) {
296 /*
297 * Controlling process.
298 * Signal foreground pgrp,
299 * drain controlling terminal
300 * and revoke access to controlling terminal.
301 */
302 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
303 tp = sp->s_ttyp;
304 if (sp->s_ttyp->t_pgrp) {
305 PGRP_LOCK(sp->s_ttyp->t_pgrp);
306 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
307 PGRP_UNLOCK(sp->s_ttyp->t_pgrp);
308 }
309 /* XXX tp should be locked. */
310 sx_xunlock(&proctree_lock);
311 (void) ttywait(tp);
312 sx_xlock(&proctree_lock);
313 /*
314 * The tty could have been revoked
315 * if we blocked.
316 */
317 if (sp->s_ttyvp) {
318 ttyvp = sp->s_ttyvp;
319 SESS_LOCK(p->p_session);
320 sp->s_ttyvp = NULL;
321 SESS_UNLOCK(p->p_session);
322 sx_xunlock(&proctree_lock);
323 VOP_REVOKE(ttyvp, REVOKEALL);
324 vrele(ttyvp);
325 sx_xlock(&proctree_lock);
326 }
327 }
328 if (sp->s_ttyvp) {
329 ttyvp = sp->s_ttyvp;
330 SESS_LOCK(p->p_session);
331 sp->s_ttyvp = NULL;
332 SESS_UNLOCK(p->p_session);
333 vrele(ttyvp);
334 }
335 /*
336 * s_ttyp is not zero'd; we use this to indicate
337 * that the session once had a controlling terminal.
338 * (for logging and informational purposes)
339 */
340 }
341 SESS_LOCK(p->p_session);
342 sp->s_leader = NULL;
343 SESS_UNLOCK(p->p_session);
344 }
345 fixjobc(p, p->p_pgrp, 0);
346 sx_xunlock(&proctree_lock);
347 (void)acct_process(td);
348 mtx_unlock(&Giant);
349 #ifdef KTRACE
350 /*
351 * release trace file
352 */
353 PROC_LOCK(p);
354 mtx_lock(&ktrace_mtx);
355 p->p_traceflag = 0; /* don't trace the vrele() */
356 tracevp = p->p_tracevp;
357 p->p_tracevp = NULL;
358 tracecred = p->p_tracecred;
359 p->p_tracecred = NULL;
360 mtx_unlock(&ktrace_mtx);
361 PROC_UNLOCK(p);
362 if (tracevp != NULL) {
363 mtx_lock(&Giant);
364 vrele(tracevp);
365 mtx_unlock(&Giant);
366 }
367 if (tracecred != NULL)
368 crfree(tracecred);
369 #endif
370 /*
371 * Release reference to text vnode
372 */
373 if ((vtmp = p->p_textvp) != NULL) {
374 p->p_textvp = NULL;
375 mtx_lock(&Giant);
376 vrele(vtmp);
377 mtx_unlock(&Giant);
378 }
379
380 /*
381 * Release our limits structure.
382 */
383 PROC_LOCK(p);
384 plim = p->p_limit;
385 p->p_limit = NULL;
386 PROC_UNLOCK(p);
387 lim_free(plim);
388
389 /*
390 * Remove proc from allproc queue and pidhash chain.
391 * Place onto zombproc. Unlink from parent's child list.
392 */
393 sx_xlock(&allproc_lock);
394 LIST_REMOVE(p, p_list);
395 LIST_INSERT_HEAD(&zombproc, p, p_list);
396 LIST_REMOVE(p, p_hash);
397 sx_xunlock(&allproc_lock);
398
399 sx_xlock(&proctree_lock);
400 q = LIST_FIRST(&p->p_children);
401 if (q != NULL) /* only need this if any child is S_ZOMB */
402 wakeup(initproc);
403 for (; q != NULL; q = nq) {
404 nq = LIST_NEXT(q, p_sibling);
405 PROC_LOCK(q);
406 proc_reparent(q, initproc);
407 q->p_sigparent = SIGCHLD;
408 /*
409 * Traced processes are killed
410 * since their existence means someone is screwing up.
411 */
412 if (q->p_flag & P_TRACED) {
413 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
414 psignal(q, SIGKILL);
415 }
416 PROC_UNLOCK(q);
417 }
418
419 /*
420 * Save exit status and final rusage info, adding in child rusage
421 * info and self times.
422 */
423 mtx_lock(&Giant);
424 PROC_LOCK(p);
425 p->p_xstat = rv;
426 p->p_xthread = td;
427 *p->p_ru = p->p_stats->p_ru;
428 mtx_lock_spin(&sched_lock);
429 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
430 mtx_unlock_spin(&sched_lock);
431 ruadd(p->p_ru, &p->p_stats->p_cru);
432
433 mtx_unlock(&Giant);
434 /*
435 * Notify interested parties of our demise.
436 */
437 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT);
438 /*
439 * Just delete all entries in the p_klist. At this point we won't
440 * report any more events, and there are nasty race conditions that
441 * can beat us if we don't.
442 */
443 knlist_clear(&p->p_klist, 1);
444
445 /*
446 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
447 * flag set, or if the handler is set to SIG_IGN, notify process
448 * 1 instead (and hope it will handle this situation).
449 */
450 PROC_LOCK(p->p_pptr);
451 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
452 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
453 struct proc *pp;
454
455 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
456 pp = p->p_pptr;
457 PROC_UNLOCK(pp);
458 proc_reparent(p, initproc);
459 p->p_sigparent = SIGCHLD;
460 PROC_LOCK(p->p_pptr);
461 /*
462 * If this was the last child of our parent, notify
463 * parent, so in case he was wait(2)ing, he will
464 * continue.
465 */
466 if (LIST_EMPTY(&pp->p_children))
467 wakeup(pp);
468 } else
469 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
470
471 if (p->p_pptr == initproc)
472 psignal(p->p_pptr, SIGCHLD);
473 else if (p->p_sigparent != 0)
474 psignal(p->p_pptr, p->p_sigparent);
475 PROC_UNLOCK(p->p_pptr);
476
477 /*
478 * If this is a kthread, then wakeup anyone waiting for it to exit.
479 */
480 if (p->p_flag & P_KTHREAD)
481 wakeup(p);
482 PROC_UNLOCK(p);
483
484 /*
485 * Finally, call machine-dependent code to release the remaining
486 * resources including address space.
487 * The address space is released by "vmspace_exitfree(p)" in
488 * vm_waitproc().
489 */
490 cpu_exit(td);
491
492 PROC_LOCK(p);
493 PROC_LOCK(p->p_pptr);
494 sx_xunlock(&proctree_lock);
495
496 while (mtx_owned(&Giant))
497 mtx_unlock(&Giant);
498
499 /*
500 * We have to wait until after acquiring all locks before
501 * changing p_state. We need to avoid any possibly context
502 * switches while marked as a zombie including blocking on
503 * a mutex.
504 */
505 mtx_lock_spin(&sched_lock);
506 p->p_state = PRS_ZOMBIE;
507 critical_enter();
508 mtx_unlock_spin(&sched_lock);
509
510 wakeup(p->p_pptr);
511 /*
512 * XXX hack, swap in parent process, please see TDP_WAKEPROC0
513 * code, because TDP_WAKEPROC0 is only useful if thread is
514 * leaving critical region, but here we never leave and
515 * thread_exit() will call cpu_throw(), TDP_WAKEPROC0 is never
516 * cleared.
517 */
518 if (p->p_pptr->p_sflag & PS_SWAPINREQ)
519 wakeup(&proc0);
520 PROC_UNLOCK(p->p_pptr);
521
522 mtx_lock_spin(&sched_lock);
523 critical_exit();
524
525 /* Do the same timestamp bookkeeping that mi_switch() would do. */
526 binuptime(&new_switchtime);
527 bintime_add(&p->p_runtime, &new_switchtime);
528 bintime_sub(&p->p_runtime, PCPU_PTR(switchtime));
529 PCPU_SET(switchtime, new_switchtime);
530 PCPU_SET(switchticks, ticks);
531
532 cnt.v_swtch++;
533 sched_exit(p->p_pptr, td);
534
535 /*
536 * hopefully no one will try to deliver a signal to the process this
537 * late in the game.
538 */
539 knlist_destroy(&p->p_klist);
540
541 /*
542 * Make sure the scheduler takes this thread out of its tables etc.
543 * This will also release this thread's reference to the ucred.
544 * Other thread parts to release include pcb bits and such.
545 */
546 thread_exit();
547 }
548
549 #ifdef COMPAT_43
550 /*
551 * MPSAFE. The dirty work is handled by kern_wait().
552 */
553 int
554 owait(struct thread *td, struct owait_args *uap __unused)
555 {
556 int error, status;
557
558 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
559 if (error == 0)
560 td->td_retval[1] = status;
561 return (error);
562 }
563 #endif /* COMPAT_43 */
564
565 /*
566 * MPSAFE. The dirty work is handled by kern_wait().
567 */
568 int
569 wait4(struct thread *td, struct wait_args *uap)
570 {
571 struct rusage ru;
572 int error, status;
573
574 error = kern_wait(td, uap->pid, &status, uap->options, &ru);
575 if (uap->status != NULL && error == 0)
576 error = copyout(&status, uap->status, sizeof(status));
577 if (uap->rusage != NULL && error == 0)
578 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
579 return (error);
580 }
581
582 int
583 kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage)
584 {
585 int nfound;
586 struct proc *p, *q, *t;
587 int error;
588
589 q = td->td_proc;
590 if (pid == 0) {
591 PROC_LOCK(q);
592 pid = -q->p_pgid;
593 PROC_UNLOCK(q);
594 }
595 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
596 return (EINVAL);
597 loop:
598 if (q->p_flag & P_STATCHILD) {
599 PROC_LOCK(q);
600 q->p_flag &= ~P_STATCHILD;
601 PROC_UNLOCK(q);
602 }
603 nfound = 0;
604 sx_xlock(&proctree_lock);
605 LIST_FOREACH(p, &q->p_children, p_sibling) {
606 PROC_LOCK(p);
607 if (pid != WAIT_ANY &&
608 p->p_pid != pid && p->p_pgid != -pid) {
609 PROC_UNLOCK(p);
610 continue;
611 }
612
613 /*
614 * This special case handles a kthread spawned by linux_clone
615 * (see linux_misc.c). The linux_wait4 and linux_waitpid
616 * functions need to be able to distinguish between waiting
617 * on a process and waiting on a thread. It is a thread if
618 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
619 * signifies we want to wait for threads and not processes.
620 */
621 if ((p->p_sigparent != SIGCHLD) ^
622 ((options & WLINUXCLONE) != 0)) {
623 PROC_UNLOCK(p);
624 continue;
625 }
626
627 nfound++;
628 if (p->p_state == PRS_ZOMBIE) {
629 td->td_retval[0] = p->p_pid;
630 if (status)
631 *status = p->p_xstat; /* convert to int */
632 if (rusage)
633 *rusage = *p->p_ru;
634
635 /*
636 * If we got the child via a ptrace 'attach',
637 * we need to give it back to the old parent.
638 */
639 PROC_UNLOCK(p);
640 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
641 PROC_LOCK(p);
642 p->p_oppid = 0;
643 proc_reparent(p, t);
644 PROC_UNLOCK(p);
645 psignal(t, SIGCHLD);
646 wakeup(t);
647 PROC_UNLOCK(t);
648 sx_xunlock(&proctree_lock);
649 return (0);
650 }
651
652 /*
653 * Remove other references to this process to ensure
654 * we have an exclusive reference.
655 */
656 sx_xlock(&allproc_lock);
657 LIST_REMOVE(p, p_list); /* off zombproc */
658 sx_xunlock(&allproc_lock);
659 LIST_REMOVE(p, p_sibling);
660 leavepgrp(p);
661 sx_xunlock(&proctree_lock);
662
663 /*
664 * As a side effect of this lock, we know that
665 * all other writes to this proc are visible now, so
666 * no more locking is needed for p.
667 */
668 mtx_lock(&Giant);
669 PROC_LOCK(p);
670 p->p_xstat = 0; /* XXX: why? */
671 PROC_UNLOCK(p);
672 PROC_LOCK(q);
673 ruadd(&q->p_stats->p_cru, p->p_ru);
674 PROC_UNLOCK(q);
675 FREE(p->p_ru, M_ZOMBIE);
676 p->p_ru = NULL;
677 mtx_unlock(&Giant);
678
679 /*
680 * Decrement the count of procs running with this uid.
681 */
682 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
683
684 /*
685 * Free credentials, arguments, and sigacts
686 */
687 crfree(p->p_ucred);
688 p->p_ucred = NULL;
689 pargs_drop(p->p_args);
690 p->p_args = NULL;
691 sigacts_free(p->p_sigacts);
692 p->p_sigacts = NULL;
693
694 /*
695 * do any thread-system specific cleanups
696 */
697 thread_wait(p);
698
699 /*
700 * Give vm and machine-dependent layer a chance
701 * to free anything that cpu_exit couldn't
702 * release while still running in process context.
703 */
704 vm_waitproc(p);
705 #ifdef MAC
706 mac_destroy_proc(p);
707 #endif
708 KASSERT(FIRST_THREAD_IN_PROC(p),
709 ("kern_wait: no residual thread!"));
710 uma_zfree(proc_zone, p);
711 sx_xlock(&allproc_lock);
712 nprocs--;
713 sx_xunlock(&allproc_lock);
714 return (0);
715 }
716 mtx_lock_spin(&sched_lock);
717 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) &&
718 ((p->p_flag & P_WAITED) == 0) &&
719 (p->p_flag & P_TRACED || options & WUNTRACED)) {
720 mtx_unlock_spin(&sched_lock);
721 p->p_flag |= P_WAITED;
722 sx_xunlock(&proctree_lock);
723 td->td_retval[0] = p->p_pid;
724 if (status)
725 *status = W_STOPCODE(p->p_xstat);
726 PROC_UNLOCK(p);
727 return (0);
728 }
729 mtx_unlock_spin(&sched_lock);
730 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) {
731 sx_xunlock(&proctree_lock);
732 td->td_retval[0] = p->p_pid;
733 p->p_flag &= ~P_CONTINUED;
734 PROC_UNLOCK(p);
735
736 if (status)
737 *status = SIGCONT;
738 return (0);
739 }
740 PROC_UNLOCK(p);
741 }
742 if (nfound == 0) {
743 sx_xunlock(&proctree_lock);
744 return (ECHILD);
745 }
746 if (options & WNOHANG) {
747 sx_xunlock(&proctree_lock);
748 td->td_retval[0] = 0;
749 return (0);
750 }
751 PROC_LOCK(q);
752 sx_xunlock(&proctree_lock);
753 if (q->p_flag & P_STATCHILD) {
754 q->p_flag &= ~P_STATCHILD;
755 error = 0;
756 } else
757 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
758 PROC_UNLOCK(q);
759 if (error)
760 return (error);
761 goto loop;
762 }
763
764 /*
765 * Make process 'parent' the new parent of process 'child'.
766 * Must be called with an exclusive hold of proctree lock.
767 */
768 void
769 proc_reparent(struct proc *child, struct proc *parent)
770 {
771
772 sx_assert(&proctree_lock, SX_XLOCKED);
773 PROC_LOCK_ASSERT(child, MA_OWNED);
774 if (child->p_pptr == parent)
775 return;
776
777 LIST_REMOVE(child, p_sibling);
778 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
779 child->p_pptr = parent;
780 }
Cache object: 6a40ea6fc88be4ae784dfc45ee660945
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