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