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_thrworkq.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysproto.h>
47 #include <sys/capsicum.h>
48 #include <sys/eventhandler.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/procdesc.h>
55 #include <sys/pioctl.h>
56 #include <sys/jail.h>
57 #include <sys/tty.h>
58 #include <sys/wait.h>
59 #include <sys/vmmeter.h>
60 #include <sys/vnode.h>
61 #include <sys/racct.h>
62 #include <sys/resourcevar.h>
63 #include <sys/sbuf.h>
64 #include <sys/signalvar.h>
65 #include <sys/sched.h>
66 #include <sys/sx.h>
67 #include <sys/syscallsubr.h>
68 #include <sys/syslog.h>
69 #include <sys/ptrace.h>
70 #include <sys/acct.h> /* for acct_process() function prototype */
71 #include <sys/filedesc.h>
72 #include <sys/sdt.h>
73 #include <sys/shm.h>
74 #include <sys/sem.h>
75 #include <sys/umtx.h>
76 #ifdef THRWORKQ
77 #include <sys/thrworkq.h>
78 #endif
79 #ifdef KTRACE
80 #include <sys/ktrace.h>
81 #endif
82
83 #include <security/audit/audit.h>
84 #include <security/mac/mac_framework.h>
85
86 #include <vm/vm.h>
87 #include <vm/vm_extern.h>
88 #include <vm/vm_param.h>
89 #include <vm/pmap.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_page.h>
92 #include <vm/uma.h>
93 #include <vm/vm_domain.h>
94
95 #ifdef KDTRACE_HOOKS
96 #include <sys/dtrace_bsd.h>
97 dtrace_execexit_func_t dtrace_fasttrap_exit;
98 #endif
99
100 SDT_PROVIDER_DECLARE(proc);
101 SDT_PROBE_DEFINE1(proc, , , exit, "int");
102
103 /* Hook for NFS teardown procedure. */
104 void (*nlminfo_release_p)(struct proc *p);
105
106 struct proc *
proc_realparent(struct proc * child)107 proc_realparent(struct proc *child)
108 {
109 struct proc *p, *parent;
110
111 sx_assert(&proctree_lock, SX_LOCKED);
112 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) {
113 if (child->p_oppid == 0 ||
114 child->p_pptr->p_pid == child->p_oppid)
115 parent = child->p_pptr;
116 else
117 parent = initproc;
118 return (parent);
119 }
120 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
121 /* Cannot use LIST_PREV(), since the list head is not known. */
122 p = __containerof(p->p_orphan.le_prev, struct proc,
123 p_orphan.le_next);
124 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
125 ("missing P_ORPHAN %p", p));
126 }
127 parent = __containerof(p->p_orphan.le_prev, struct proc,
128 p_orphans.lh_first);
129 return (parent);
130 }
131
132 void
reaper_abandon_children(struct proc * p,bool exiting)133 reaper_abandon_children(struct proc *p, bool exiting)
134 {
135 struct proc *p1, *p2, *ptmp;
136
137 sx_assert(&proctree_lock, SX_LOCKED);
138 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
139 if ((p->p_treeflag & P_TREE_REAPER) == 0)
140 return;
141 p1 = p->p_reaper;
142 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
143 LIST_REMOVE(p2, p_reapsibling);
144 p2->p_reaper = p1;
145 p2->p_reapsubtree = p->p_reapsubtree;
146 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
147 if (exiting && p2->p_pptr == p) {
148 PROC_LOCK(p2);
149 proc_reparent(p2, p1);
150 PROC_UNLOCK(p2);
151 }
152 }
153 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
154 p->p_treeflag &= ~P_TREE_REAPER;
155 }
156
157 static void
clear_orphan(struct proc * p)158 clear_orphan(struct proc *p)
159 {
160 struct proc *p1;
161
162 sx_assert(&proctree_lock, SA_XLOCKED);
163 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
164 return;
165 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
166 p1 = LIST_NEXT(p, p_orphan);
167 if (p1 != NULL)
168 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
169 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
170 }
171 LIST_REMOVE(p, p_orphan);
172 p->p_treeflag &= ~P_TREE_ORPHANED;
173 }
174
175 /*
176 * exit -- death of process.
177 */
178 void
sys_sys_exit(struct thread * td,struct sys_exit_args * uap)179 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
180 {
181
182 exit1(td, uap->rval, 0);
183 /* NOTREACHED */
184 }
185
186 /*
187 * Exit: deallocate address space and other resources, change proc state to
188 * zombie, and unlink proc from allproc and parent's lists. Save exit status
189 * and rusage for wait(). Check for child processes and orphan them.
190 */
191 void
exit1(struct thread * td,int rval,int signo)192 exit1(struct thread *td, int rval, int signo)
193 {
194 struct proc *p, *nq, *q, *t;
195 struct thread *tdt;
196 struct vnode *ttyvp = NULL;
197
198 mtx_assert(&Giant, MA_NOTOWNED);
199 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
200
201 p = td->td_proc;
202 /*
203 * XXX in case we're rebooting we just let init die in order to
204 * work around an unsolved stack overflow seen very late during
205 * shutdown on sparc64 when the gmirror worker process exists.
206 */
207 if (p == initproc && rebooting == 0) {
208 printf("init died (signal %d, exit %d)\n", signo, rval);
209 panic("Going nowhere without my init!");
210 }
211
212 #ifdef THRWORKQ
213 /*
214 * Check if this process has a thread workqueue.
215 */
216 thrworkq_exit(p);
217 #endif
218
219 /*
220 * Deref SU mp, since the thread does not return to userspace.
221 */
222 if (softdep_ast_cleanup != NULL)
223 softdep_ast_cleanup();
224
225 /*
226 * MUST abort all other threads before proceeding past here.
227 */
228 PROC_LOCK(p);
229 /*
230 * First check if some other thread or external request got
231 * here before us. If so, act appropriately: exit or suspend.
232 * We must ensure that stop requests are handled before we set
233 * P_WEXIT.
234 */
235 thread_suspend_check(0);
236 while (p->p_flag & P_HADTHREADS) {
237 /*
238 * Kill off the other threads. This requires
239 * some co-operation from other parts of the kernel
240 * so it may not be instantaneous. With this state set
241 * any thread entering the kernel from userspace will
242 * thread_exit() in trap(). Any thread attempting to
243 * sleep will return immediately with EINTR or EWOULDBLOCK
244 * which will hopefully force them to back out to userland
245 * freeing resources as they go. Any thread attempting
246 * to return to userland will thread_exit() from userret().
247 * thread_exit() will unsuspend us when the last of the
248 * other threads exits.
249 * If there is already a thread singler after resumption,
250 * calling thread_single will fail; in that case, we just
251 * re-check all suspension request, the thread should
252 * either be suspended there or exit.
253 */
254 if (!thread_single(p, SINGLE_EXIT))
255 /*
256 * All other activity in this process is now
257 * stopped. Threading support has been turned
258 * off.
259 */
260 break;
261 /*
262 * Recheck for new stop or suspend requests which
263 * might appear while process lock was dropped in
264 * thread_single().
265 */
266 thread_suspend_check(0);
267 }
268 KASSERT(p->p_numthreads == 1,
269 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
270 racct_sub(p, RACCT_NTHR, 1);
271
272 /* Let event handler change exit status */
273 p->p_xexit = rval;
274 p->p_xsig = signo;
275
276 /*
277 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
278 * on our vmspace, so we should block below until they have
279 * released their reference to us. Note that if they have
280 * requested S_EXIT stops we will block here until they ack
281 * via PIOCCONT.
282 */
283 _STOPEVENT(p, S_EXIT, 0);
284
285 /*
286 * Ignore any pending request to stop due to a stop signal.
287 * Once P_WEXIT is set, future requests will be ignored as
288 * well.
289 */
290 p->p_flag &= ~P_STOPPED_SIG;
291 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
292
293 /*
294 * Note that we are exiting and do another wakeup of anyone in
295 * PIOCWAIT in case they aren't listening for S_EXIT stops or
296 * decided to wait again after we told them we are exiting.
297 */
298 p->p_flag |= P_WEXIT;
299 wakeup(&p->p_stype);
300
301 /*
302 * Wait for any processes that have a hold on our vmspace to
303 * release their reference.
304 */
305 while (p->p_lock > 0)
306 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
307
308 PROC_UNLOCK(p);
309 /* Drain the limit callout while we don't have the proc locked */
310 callout_drain(&p->p_limco);
311
312 #ifdef AUDIT
313 /*
314 * The Sun BSM exit token contains two components: an exit status as
315 * passed to exit(), and a return value to indicate what sort of exit
316 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
317 * what the return value is.
318 */
319 AUDIT_ARG_EXIT(rval, 0);
320 AUDIT_SYSCALL_EXIT(0, td);
321 #endif
322
323 /* Are we a task leader with peers? */
324 if (p->p_peers != NULL && p == p->p_leader) {
325 mtx_lock(&ppeers_lock);
326 q = p->p_peers;
327 while (q != NULL) {
328 PROC_LOCK(q);
329 kern_psignal(q, SIGKILL);
330 PROC_UNLOCK(q);
331 q = q->p_peers;
332 }
333 while (p->p_peers != NULL)
334 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
335 mtx_unlock(&ppeers_lock);
336 }
337
338 /*
339 * Check if any loadable modules need anything done at process exit.
340 * E.g. SYSV IPC stuff.
341 * Event handler could change exit status.
342 * XXX what if one of these generates an error?
343 */
344 EVENTHANDLER_INVOKE(process_exit, p);
345
346 /*
347 * If parent is waiting for us to exit or exec,
348 * P_PPWAIT is set; we will wakeup the parent below.
349 */
350 PROC_LOCK(p);
351 stopprofclock(p);
352 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
353
354 /*
355 * Stop the real interval timer. If the handler is currently
356 * executing, prevent it from rearming itself and let it finish.
357 */
358 if (timevalisset(&p->p_realtimer.it_value) &&
359 callout_stop(&p->p_itcallout) == 0) {
360 timevalclear(&p->p_realtimer.it_interval);
361 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
362 KASSERT(!timevalisset(&p->p_realtimer.it_value),
363 ("realtime timer is still armed"));
364 }
365 PROC_UNLOCK(p);
366
367 /*
368 * Reset any sigio structures pointing to us as a result of
369 * F_SETOWN with our pid.
370 */
371 funsetownlst(&p->p_sigiolst);
372
373 /*
374 * If this process has an nlminfo data area (for lockd), release it
375 */
376 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
377 (*nlminfo_release_p)(p);
378
379 /*
380 * Close open files and release open-file table.
381 * This may block!
382 */
383 fdescfree(td);
384
385 /*
386 * If this thread tickled GEOM, we need to wait for the giggling to
387 * stop before we return to userland
388 */
389 if (td->td_pflags & TDP_GEOM)
390 g_waitidle();
391
392 /*
393 * Remove ourself from our leader's peer list and wake our leader.
394 */
395 if (p->p_leader->p_peers != NULL) {
396 mtx_lock(&ppeers_lock);
397 if (p->p_leader->p_peers != NULL) {
398 q = p->p_leader;
399 while (q->p_peers != p)
400 q = q->p_peers;
401 q->p_peers = p->p_peers;
402 wakeup(p->p_leader);
403 }
404 mtx_unlock(&ppeers_lock);
405 }
406
407 vmspace_exit(td);
408
409 sx_xlock(&proctree_lock);
410 if (SESS_LEADER(p)) {
411 struct session *sp = p->p_session;
412 struct tty *tp;
413
414 /*
415 * s_ttyp is not zero'd; we use this to indicate that
416 * the session once had a controlling terminal. (for
417 * logging and informational purposes)
418 */
419 SESS_LOCK(sp);
420 ttyvp = sp->s_ttyvp;
421 tp = sp->s_ttyp;
422 sp->s_ttyvp = NULL;
423 sp->s_ttydp = NULL;
424 sp->s_leader = NULL;
425 SESS_UNLOCK(sp);
426
427 /*
428 * Signal foreground pgrp and revoke access to
429 * controlling terminal if it has not been revoked
430 * already.
431 *
432 * Because the TTY may have been revoked in the mean
433 * time and could already have a new session associated
434 * with it, make sure we don't send a SIGHUP to a
435 * foreground process group that does not belong to this
436 * session.
437 */
438
439 if (tp != NULL) {
440 tty_lock(tp);
441 if (tp->t_session == sp)
442 tty_signal_pgrp(tp, SIGHUP);
443 tty_unlock(tp);
444 }
445
446 if (ttyvp != NULL) {
447 sx_xunlock(&proctree_lock);
448 if (vn_lock(ttyvp, LK_EXCLUSIVE) == 0) {
449 VOP_REVOKE(ttyvp, REVOKEALL);
450 VOP_UNLOCK(ttyvp, 0);
451 }
452 sx_xlock(&proctree_lock);
453 }
454 }
455 fixjobc(p, p->p_pgrp, 0);
456 sx_xunlock(&proctree_lock);
457 (void)acct_process(td);
458
459 /* Release the TTY now we've unlocked everything. */
460 if (ttyvp != NULL)
461 vrele(ttyvp);
462 #ifdef KTRACE
463 ktrprocexit(td);
464 #endif
465 /*
466 * Release reference to text vnode
467 */
468 if (p->p_textvp != NULL) {
469 vrele(p->p_textvp);
470 p->p_textvp = NULL;
471 }
472
473 /*
474 * Release our limits structure.
475 */
476 lim_free(p->p_limit);
477 p->p_limit = NULL;
478
479 tidhash_remove(td);
480
481 /*
482 * Remove proc from allproc queue and pidhash chain.
483 * Place onto zombproc. Unlink from parent's child list.
484 */
485 sx_xlock(&allproc_lock);
486 LIST_REMOVE(p, p_list);
487 LIST_INSERT_HEAD(&zombproc, p, p_list);
488 LIST_REMOVE(p, p_hash);
489 sx_xunlock(&allproc_lock);
490
491 /*
492 * Call machine-dependent code to release any
493 * machine-dependent resources other than the 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, NULL, "process (pid %d) exiting", p->p_pid);
500
501 /*
502 * Reparent all children processes:
503 * - traced ones to the original parent (or init if we are that parent)
504 * - the rest to init
505 */
506 sx_xlock(&proctree_lock);
507 q = LIST_FIRST(&p->p_children);
508 if (q != NULL) /* only need this if any child is S_ZOMB */
509 wakeup(q->p_reaper);
510 for (; q != NULL; q = nq) {
511 nq = LIST_NEXT(q, p_sibling);
512 PROC_LOCK(q);
513 q->p_sigparent = SIGCHLD;
514
515 if (!(q->p_flag & P_TRACED)) {
516 proc_reparent(q, q->p_reaper);
517 } else {
518 /*
519 * Traced processes are killed since their existence
520 * means someone is screwing up.
521 */
522 t = proc_realparent(q);
523 if (t == p) {
524 proc_reparent(q, q->p_reaper);
525 } else {
526 PROC_LOCK(t);
527 proc_reparent(q, t);
528 PROC_UNLOCK(t);
529 }
530 /*
531 * Since q was found on our children list, the
532 * proc_reparent() call moved q to the orphan
533 * list due to present P_TRACED flag. Clear
534 * orphan link for q now while q is locked.
535 */
536 clear_orphan(q);
537 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
538 FOREACH_THREAD_IN_PROC(q, tdt)
539 tdt->td_dbgflags &= ~TDB_SUSPEND;
540 kern_psignal(q, SIGKILL);
541 }
542 PROC_UNLOCK(q);
543 }
544
545 /*
546 * Also get rid of our orphans.
547 */
548 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
549 PROC_LOCK(q);
550 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
551 q->p_pid);
552 clear_orphan(q);
553 PROC_UNLOCK(q);
554 }
555
556 /* Save exit status. */
557 PROC_LOCK(p);
558 p->p_xthread = td;
559
560 /* Tell the prison that we are gone. */
561 prison_proc_free(p->p_ucred->cr_prison);
562
563 #ifdef KDTRACE_HOOKS
564 /*
565 * Tell the DTrace fasttrap provider about the exit if it
566 * has declared an interest.
567 */
568 if (dtrace_fasttrap_exit)
569 dtrace_fasttrap_exit(p);
570 #endif
571
572 /*
573 * Notify interested parties of our demise.
574 */
575 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT);
576
577 #ifdef KDTRACE_HOOKS
578 int reason = CLD_EXITED;
579 if (WCOREDUMP(signo))
580 reason = CLD_DUMPED;
581 else if (WIFSIGNALED(signo))
582 reason = CLD_KILLED;
583 SDT_PROBE1(proc, , , exit, reason);
584 #endif
585
586 /*
587 * Just delete all entries in the p_klist. At this point we won't
588 * report any more events, and there are nasty race conditions that
589 * can beat us if we don't.
590 */
591 knlist_clear(&p->p_klist, 1);
592
593 /*
594 * If this is a process with a descriptor, we may not need to deliver
595 * a signal to the parent. proctree_lock is held over
596 * procdesc_exit() to serialize concurrent calls to close() and
597 * exit().
598 */
599 if (p->p_procdesc == NULL || procdesc_exit(p)) {
600 /*
601 * Notify parent that we're gone. If parent has the
602 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
603 * notify process 1 instead (and hope it will handle this
604 * situation).
605 */
606 PROC_LOCK(p->p_pptr);
607 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
608 if (p->p_pptr->p_sigacts->ps_flag &
609 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
610 struct proc *pp;
611
612 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
613 pp = p->p_pptr;
614 PROC_UNLOCK(pp);
615 proc_reparent(p, p->p_reaper);
616 p->p_sigparent = SIGCHLD;
617 PROC_LOCK(p->p_pptr);
618
619 /*
620 * Notify parent, so in case he was wait(2)ing or
621 * executing waitpid(2) with our pid, he will
622 * continue.
623 */
624 wakeup(pp);
625 } else
626 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
627
628 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc)
629 childproc_exited(p);
630 else if (p->p_sigparent != 0) {
631 if (p->p_sigparent == SIGCHLD)
632 childproc_exited(p);
633 else /* LINUX thread */
634 kern_psignal(p->p_pptr, p->p_sigparent);
635 }
636 } else
637 PROC_LOCK(p->p_pptr);
638 sx_xunlock(&proctree_lock);
639
640 /*
641 * The state PRS_ZOMBIE prevents other proesses from sending
642 * signal to the process, to avoid memory leak, we free memory
643 * for signal queue at the time when the state is set.
644 */
645 sigqueue_flush(&p->p_sigqueue);
646 sigqueue_flush(&td->td_sigqueue);
647
648 /*
649 * We have to wait until after acquiring all locks before
650 * changing p_state. We need to avoid all possible context
651 * switches (including ones from blocking on a mutex) while
652 * marked as a zombie. We also have to set the zombie state
653 * before we release the parent process' proc lock to avoid
654 * a lost wakeup. So, we first call wakeup, then we grab the
655 * sched lock, update the state, and release the parent process'
656 * proc lock.
657 */
658 wakeup(p->p_pptr);
659 cv_broadcast(&p->p_pwait);
660 sched_exit(p->p_pptr, td);
661 umtx_thread_exit(td);
662 PROC_SLOCK(p);
663 p->p_state = PRS_ZOMBIE;
664 PROC_UNLOCK(p->p_pptr);
665
666 /*
667 * Hopefully no one will try to deliver a signal to the process this
668 * late in the game.
669 */
670 knlist_destroy(&p->p_klist);
671
672 /*
673 * Save our children's rusage information in our exit rusage.
674 */
675 PROC_STATLOCK(p);
676 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
677 PROC_STATUNLOCK(p);
678
679 /*
680 * Make sure the scheduler takes this thread out of its tables etc.
681 * This will also release this thread's reference to the ucred.
682 * Other thread parts to release include pcb bits and such.
683 */
684 thread_exit();
685 }
686
687
688 #ifndef _SYS_SYSPROTO_H_
689 struct abort2_args {
690 char *why;
691 int nargs;
692 void **args;
693 };
694 #endif
695
696 int
sys_abort2(struct thread * td,struct abort2_args * uap)697 sys_abort2(struct thread *td, struct abort2_args *uap)
698 {
699 struct proc *p = td->td_proc;
700 struct sbuf *sb;
701 void *uargs[16];
702 int error, i, sig;
703
704 /*
705 * Do it right now so we can log either proper call of abort2(), or
706 * note, that invalid argument was passed. 512 is big enough to
707 * handle 16 arguments' descriptions with additional comments.
708 */
709 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
710 sbuf_clear(sb);
711 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
712 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
713 /*
714 * Since we can't return from abort2(), send SIGKILL in cases, where
715 * abort2() was called improperly
716 */
717 sig = SIGKILL;
718 /* Prevent from DoSes from user-space. */
719 if (uap->nargs < 0 || uap->nargs > 16)
720 goto out;
721 if (uap->nargs > 0) {
722 if (uap->args == NULL)
723 goto out;
724 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
725 if (error != 0)
726 goto out;
727 }
728 /*
729 * Limit size of 'reason' string to 128. Will fit even when
730 * maximal number of arguments was chosen to be logged.
731 */
732 if (uap->why != NULL) {
733 error = sbuf_copyin(sb, uap->why, 128);
734 if (error < 0)
735 goto out;
736 } else {
737 sbuf_printf(sb, "(null)");
738 }
739 if (uap->nargs > 0) {
740 sbuf_printf(sb, "(");
741 for (i = 0;i < uap->nargs; i++)
742 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
743 sbuf_printf(sb, ")");
744 }
745 /*
746 * Final stage: arguments were proper, string has been
747 * successfully copied from userspace, and copying pointers
748 * from user-space succeed.
749 */
750 sig = SIGABRT;
751 out:
752 if (sig == SIGKILL) {
753 sbuf_trim(sb);
754 sbuf_printf(sb, " (Reason text inaccessible)");
755 }
756 sbuf_cat(sb, "\n");
757 sbuf_finish(sb);
758 log(LOG_INFO, "%s", sbuf_data(sb));
759 sbuf_delete(sb);
760 exit1(td, 0, sig);
761 return (0);
762 }
763
764
765 #ifdef COMPAT_43
766 /*
767 * The dirty work is handled by kern_wait().
768 */
769 int
owait(struct thread * td,struct owait_args * uap __unused)770 owait(struct thread *td, struct owait_args *uap __unused)
771 {
772 int error, status;
773
774 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
775 if (error == 0)
776 td->td_retval[1] = status;
777 return (error);
778 }
779 #endif /* COMPAT_43 */
780
781 /*
782 * The dirty work is handled by kern_wait().
783 */
784 int
sys_wait4(struct thread * td,struct wait4_args * uap)785 sys_wait4(struct thread *td, struct wait4_args *uap)
786 {
787 struct rusage ru, *rup;
788 int error, status;
789
790 if (uap->rusage != NULL)
791 rup = &ru;
792 else
793 rup = NULL;
794 error = kern_wait(td, uap->pid, &status, uap->options, rup);
795 if (uap->status != NULL && error == 0)
796 error = copyout(&status, uap->status, sizeof(status));
797 if (uap->rusage != NULL && error == 0)
798 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
799 return (error);
800 }
801
802 int
sys_wait6(struct thread * td,struct wait6_args * uap)803 sys_wait6(struct thread *td, struct wait6_args *uap)
804 {
805 struct __wrusage wru, *wrup;
806 siginfo_t si, *sip;
807 idtype_t idtype;
808 id_t id;
809 int error, status;
810
811 idtype = uap->idtype;
812 id = uap->id;
813
814 if (uap->wrusage != NULL)
815 wrup = &wru;
816 else
817 wrup = NULL;
818
819 if (uap->info != NULL) {
820 sip = &si;
821 bzero(sip, sizeof(*sip));
822 } else
823 sip = NULL;
824
825 /*
826 * We expect all callers of wait6() to know about WEXITED and
827 * WTRAPPED.
828 */
829 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
830
831 if (uap->status != NULL && error == 0)
832 error = copyout(&status, uap->status, sizeof(status));
833 if (uap->wrusage != NULL && error == 0)
834 error = copyout(&wru, uap->wrusage, sizeof(wru));
835 if (uap->info != NULL && error == 0)
836 error = copyout(&si, uap->info, sizeof(si));
837 return (error);
838 }
839
840 /*
841 * Reap the remains of a zombie process and optionally return status and
842 * rusage. Asserts and will release both the proctree_lock and the process
843 * lock as part of its work.
844 */
845 void
proc_reap(struct thread * td,struct proc * p,int * status,int options)846 proc_reap(struct thread *td, struct proc *p, int *status, int options)
847 {
848 struct proc *q, *t;
849
850 sx_assert(&proctree_lock, SA_XLOCKED);
851 PROC_LOCK_ASSERT(p, MA_OWNED);
852 PROC_SLOCK_ASSERT(p, MA_OWNED);
853 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
854
855 q = td->td_proc;
856
857 PROC_SUNLOCK(p);
858 if (status)
859 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
860 if (options & WNOWAIT) {
861 /*
862 * Only poll, returning the status. Caller does not wish to
863 * release the proc struct just yet.
864 */
865 PROC_UNLOCK(p);
866 sx_xunlock(&proctree_lock);
867 return;
868 }
869
870 PROC_LOCK(q);
871 sigqueue_take(p->p_ksi);
872 PROC_UNLOCK(q);
873
874 /*
875 * If we got the child via a ptrace 'attach', we need to give it back
876 * to the old parent.
877 */
878 if (p->p_oppid != 0 && p->p_oppid != p->p_pptr->p_pid) {
879 PROC_UNLOCK(p);
880 t = proc_realparent(p);
881 PROC_LOCK(t);
882 PROC_LOCK(p);
883 CTR2(KTR_PTRACE,
884 "wait: traced child %d moved back to parent %d", p->p_pid,
885 t->p_pid);
886 proc_reparent(p, t);
887 p->p_oppid = 0;
888 PROC_UNLOCK(p);
889 pksignal(t, SIGCHLD, p->p_ksi);
890 wakeup(t);
891 cv_broadcast(&p->p_pwait);
892 PROC_UNLOCK(t);
893 sx_xunlock(&proctree_lock);
894 return;
895 }
896 p->p_oppid = 0;
897 PROC_UNLOCK(p);
898
899 /*
900 * Remove other references to this process to ensure we have an
901 * exclusive reference.
902 */
903 sx_xlock(&allproc_lock);
904 LIST_REMOVE(p, p_list); /* off zombproc */
905 sx_xunlock(&allproc_lock);
906 LIST_REMOVE(p, p_sibling);
907 reaper_abandon_children(p, true);
908 LIST_REMOVE(p, p_reapsibling);
909 PROC_LOCK(p);
910 clear_orphan(p);
911 PROC_UNLOCK(p);
912 leavepgrp(p);
913 if (p->p_procdesc != NULL)
914 procdesc_reap(p);
915 sx_xunlock(&proctree_lock);
916
917 /*
918 * Removal from allproc list and process group list paired with
919 * PROC_LOCK which was executed during that time should guarantee
920 * nothing can reach this process anymore. As such further locking
921 * is unnecessary.
922 */
923 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
924
925 PROC_LOCK(q);
926 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
927 PROC_UNLOCK(q);
928
929 /*
930 * Decrement the count of procs running with this uid.
931 */
932 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
933
934 /*
935 * Destroy resource accounting information associated with the process.
936 */
937 #ifdef RACCT
938 if (racct_enable) {
939 PROC_LOCK(p);
940 racct_sub(p, RACCT_NPROC, 1);
941 PROC_UNLOCK(p);
942 }
943 #endif
944 racct_proc_exit(p);
945
946 /*
947 * Free credentials, arguments, and sigacts.
948 */
949 crfree(p->p_ucred);
950 proc_set_cred(p, NULL);
951 pargs_drop(p->p_args);
952 p->p_args = NULL;
953 sigacts_free(p->p_sigacts);
954 p->p_sigacts = NULL;
955
956 /*
957 * Do any thread-system specific cleanups.
958 */
959 thread_wait(p);
960
961 /*
962 * Give vm and machine-dependent layer a chance to free anything that
963 * cpu_exit couldn't release while still running in process context.
964 */
965 vm_waitproc(p);
966 #ifdef MAC
967 mac_proc_destroy(p);
968 #endif
969 /*
970 * Free any domain policy that's still hiding around.
971 */
972 vm_domain_policy_cleanup(&p->p_vm_dom_policy);
973
974 KASSERT(FIRST_THREAD_IN_PROC(p),
975 ("proc_reap: no residual thread!"));
976 uma_zfree(proc_zone, p);
977 atomic_add_int(&nprocs, -1);
978 }
979
980 static int
proc_to_reap(struct thread * td,struct proc * p,idtype_t idtype,id_t id,int * status,int options,struct __wrusage * wrusage,siginfo_t * siginfo,int check_only)981 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
982 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
983 int check_only)
984 {
985 struct rusage *rup;
986
987 sx_assert(&proctree_lock, SA_XLOCKED);
988
989 PROC_LOCK(p);
990
991 switch (idtype) {
992 case P_ALL:
993 if (p->p_procdesc != NULL) {
994 PROC_UNLOCK(p);
995 return (0);
996 }
997 break;
998 case P_PID:
999 if (p->p_pid != (pid_t)id) {
1000 PROC_UNLOCK(p);
1001 return (0);
1002 }
1003 break;
1004 case P_PGID:
1005 if (p->p_pgid != (pid_t)id) {
1006 PROC_UNLOCK(p);
1007 return (0);
1008 }
1009 break;
1010 case P_SID:
1011 if (p->p_session->s_sid != (pid_t)id) {
1012 PROC_UNLOCK(p);
1013 return (0);
1014 }
1015 break;
1016 case P_UID:
1017 if (p->p_ucred->cr_uid != (uid_t)id) {
1018 PROC_UNLOCK(p);
1019 return (0);
1020 }
1021 break;
1022 case P_GID:
1023 if (p->p_ucred->cr_gid != (gid_t)id) {
1024 PROC_UNLOCK(p);
1025 return (0);
1026 }
1027 break;
1028 case P_JAILID:
1029 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1030 PROC_UNLOCK(p);
1031 return (0);
1032 }
1033 break;
1034 /*
1035 * It seems that the thread structures get zeroed out
1036 * at process exit. This makes it impossible to
1037 * support P_SETID, P_CID or P_CPUID.
1038 */
1039 default:
1040 PROC_UNLOCK(p);
1041 return (0);
1042 }
1043
1044 if (p_canwait(td, p)) {
1045 PROC_UNLOCK(p);
1046 return (0);
1047 }
1048
1049 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1050 PROC_UNLOCK(p);
1051 return (0);
1052 }
1053
1054 /*
1055 * This special case handles a kthread spawned by linux_clone
1056 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1057 * functions need to be able to distinguish between waiting
1058 * on a process and waiting on a thread. It is a thread if
1059 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1060 * signifies we want to wait for threads and not processes.
1061 */
1062 if ((p->p_sigparent != SIGCHLD) ^
1063 ((options & WLINUXCLONE) != 0)) {
1064 PROC_UNLOCK(p);
1065 return (0);
1066 }
1067
1068 if (siginfo != NULL) {
1069 bzero(siginfo, sizeof(*siginfo));
1070 siginfo->si_errno = 0;
1071
1072 /*
1073 * SUSv4 requires that the si_signo value is always
1074 * SIGCHLD. Obey it despite the rfork(2) interface
1075 * allows to request other signal for child exit
1076 * notification.
1077 */
1078 siginfo->si_signo = SIGCHLD;
1079
1080 /*
1081 * This is still a rough estimate. We will fix the
1082 * cases TRAPPED, STOPPED, and CONTINUED later.
1083 */
1084 if (WCOREDUMP(p->p_xsig)) {
1085 siginfo->si_code = CLD_DUMPED;
1086 siginfo->si_status = WTERMSIG(p->p_xsig);
1087 } else if (WIFSIGNALED(p->p_xsig)) {
1088 siginfo->si_code = CLD_KILLED;
1089 siginfo->si_status = WTERMSIG(p->p_xsig);
1090 } else {
1091 siginfo->si_code = CLD_EXITED;
1092 siginfo->si_status = p->p_xexit;
1093 }
1094
1095 siginfo->si_pid = p->p_pid;
1096 siginfo->si_uid = p->p_ucred->cr_uid;
1097
1098 /*
1099 * The si_addr field would be useful additional
1100 * detail, but apparently the PC value may be lost
1101 * when we reach this point. bzero() above sets
1102 * siginfo->si_addr to NULL.
1103 */
1104 }
1105
1106 /*
1107 * There should be no reason to limit resources usage info to
1108 * exited processes only. A snapshot about any resources used
1109 * by a stopped process may be exactly what is needed.
1110 */
1111 if (wrusage != NULL) {
1112 rup = &wrusage->wru_self;
1113 *rup = p->p_ru;
1114 PROC_STATLOCK(p);
1115 calcru(p, &rup->ru_utime, &rup->ru_stime);
1116 PROC_STATUNLOCK(p);
1117
1118 rup = &wrusage->wru_children;
1119 *rup = p->p_stats->p_cru;
1120 calccru(p, &rup->ru_utime, &rup->ru_stime);
1121 }
1122
1123 if (p->p_state == PRS_ZOMBIE && !check_only) {
1124 PROC_SLOCK(p);
1125 proc_reap(td, p, status, options);
1126 return (-1);
1127 }
1128 PROC_UNLOCK(p);
1129 return (1);
1130 }
1131
1132 int
kern_wait(struct thread * td,pid_t pid,int * status,int options,struct rusage * rusage)1133 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1134 struct rusage *rusage)
1135 {
1136 struct __wrusage wru, *wrup;
1137 idtype_t idtype;
1138 id_t id;
1139 int ret;
1140
1141 /*
1142 * Translate the special pid values into the (idtype, pid)
1143 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1144 * kern_wait6() on its own.
1145 */
1146 if (pid == WAIT_ANY) {
1147 idtype = P_ALL;
1148 id = 0;
1149 } else if (pid < 0) {
1150 idtype = P_PGID;
1151 id = (id_t)-pid;
1152 } else {
1153 idtype = P_PID;
1154 id = (id_t)pid;
1155 }
1156
1157 if (rusage != NULL)
1158 wrup = &wru;
1159 else
1160 wrup = NULL;
1161
1162 /*
1163 * For backward compatibility we implicitly add flags WEXITED
1164 * and WTRAPPED here.
1165 */
1166 options |= WEXITED | WTRAPPED;
1167 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1168 if (rusage != NULL)
1169 *rusage = wru.wru_self;
1170 return (ret);
1171 }
1172
1173 int
kern_wait6(struct thread * td,idtype_t idtype,id_t id,int * status,int options,struct __wrusage * wrusage,siginfo_t * siginfo)1174 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1175 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1176 {
1177 struct proc *p, *q;
1178 pid_t pid;
1179 int error, nfound, ret;
1180
1181 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1182 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1183 AUDIT_ARG_VALUE(options);
1184
1185 q = td->td_proc;
1186
1187 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1188 PROC_LOCK(q);
1189 id = (id_t)q->p_pgid;
1190 PROC_UNLOCK(q);
1191 idtype = P_PGID;
1192 }
1193
1194 /* If we don't know the option, just return. */
1195 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1196 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1197 return (EINVAL);
1198 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1199 /*
1200 * We will be unable to find any matching processes,
1201 * because there are no known events to look for.
1202 * Prefer to return error instead of blocking
1203 * indefinitely.
1204 */
1205 return (EINVAL);
1206 }
1207
1208 loop:
1209 if (q->p_flag & P_STATCHILD) {
1210 PROC_LOCK(q);
1211 q->p_flag &= ~P_STATCHILD;
1212 PROC_UNLOCK(q);
1213 }
1214 nfound = 0;
1215 sx_xlock(&proctree_lock);
1216 LIST_FOREACH(p, &q->p_children, p_sibling) {
1217 pid = p->p_pid;
1218 ret = proc_to_reap(td, p, idtype, id, status, options,
1219 wrusage, siginfo, 0);
1220 if (ret == 0)
1221 continue;
1222 else if (ret == 1)
1223 nfound++;
1224 else {
1225 td->td_retval[0] = pid;
1226 return (0);
1227 }
1228
1229 PROC_LOCK(p);
1230 PROC_SLOCK(p);
1231
1232 if ((options & WTRAPPED) != 0 &&
1233 (p->p_flag & P_TRACED) != 0 &&
1234 (p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) != 0 &&
1235 (p->p_suspcount == p->p_numthreads) &&
1236 ((p->p_flag & P_WAITED) == 0)) {
1237 PROC_SUNLOCK(p);
1238 if ((options & WNOWAIT) == 0)
1239 p->p_flag |= P_WAITED;
1240 sx_xunlock(&proctree_lock);
1241
1242 if (status != NULL)
1243 *status = W_STOPCODE(p->p_xsig);
1244 if (siginfo != NULL) {
1245 siginfo->si_status = p->p_xsig;
1246 siginfo->si_code = CLD_TRAPPED;
1247 }
1248 if ((options & WNOWAIT) == 0) {
1249 PROC_LOCK(q);
1250 sigqueue_take(p->p_ksi);
1251 PROC_UNLOCK(q);
1252 }
1253
1254 CTR4(KTR_PTRACE,
1255 "wait: returning trapped pid %d status %#x (xstat %d) xthread %d",
1256 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1257 p->p_xthread != NULL ? p->p_xthread->td_tid : -1);
1258 PROC_UNLOCK(p);
1259 td->td_retval[0] = pid;
1260 return (0);
1261 }
1262 if ((options & WUNTRACED) != 0 &&
1263 (p->p_flag & P_STOPPED_SIG) != 0 &&
1264 (p->p_suspcount == p->p_numthreads) &&
1265 ((p->p_flag & P_WAITED) == 0)) {
1266 PROC_SUNLOCK(p);
1267 if ((options & WNOWAIT) == 0)
1268 p->p_flag |= P_WAITED;
1269 sx_xunlock(&proctree_lock);
1270
1271 if (status != NULL)
1272 *status = W_STOPCODE(p->p_xsig);
1273 if (siginfo != NULL) {
1274 siginfo->si_status = p->p_xsig;
1275 siginfo->si_code = CLD_STOPPED;
1276 }
1277 if ((options & WNOWAIT) == 0) {
1278 PROC_LOCK(q);
1279 sigqueue_take(p->p_ksi);
1280 PROC_UNLOCK(q);
1281 }
1282
1283 PROC_UNLOCK(p);
1284 td->td_retval[0] = pid;
1285 return (0);
1286 }
1287 PROC_SUNLOCK(p);
1288 if ((options & WCONTINUED) != 0 &&
1289 (p->p_flag & P_CONTINUED) != 0) {
1290 sx_xunlock(&proctree_lock);
1291 if ((options & WNOWAIT) == 0) {
1292 p->p_flag &= ~P_CONTINUED;
1293 PROC_LOCK(q);
1294 sigqueue_take(p->p_ksi);
1295 PROC_UNLOCK(q);
1296 }
1297 PROC_UNLOCK(p);
1298
1299 if (status != NULL)
1300 *status = SIGCONT;
1301 if (siginfo != NULL) {
1302 siginfo->si_status = SIGCONT;
1303 siginfo->si_code = CLD_CONTINUED;
1304 }
1305 td->td_retval[0] = pid;
1306 return (0);
1307 }
1308 PROC_UNLOCK(p);
1309 }
1310
1311 /*
1312 * Look in the orphans list too, to allow the parent to
1313 * collect it's child exit status even if child is being
1314 * debugged.
1315 *
1316 * Debugger detaches from the parent upon successful
1317 * switch-over from parent to child. At this point due to
1318 * re-parenting the parent loses the child to debugger and a
1319 * wait4(2) call would report that it has no children to wait
1320 * for. By maintaining a list of orphans we allow the parent
1321 * to successfully wait until the child becomes a zombie.
1322 */
1323 if (nfound == 0) {
1324 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1325 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1326 NULL, NULL, 1);
1327 if (ret != 0) {
1328 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1329 (int)td->td_retval[0]));
1330 nfound++;
1331 break;
1332 }
1333 }
1334 }
1335 if (nfound == 0) {
1336 sx_xunlock(&proctree_lock);
1337 return (ECHILD);
1338 }
1339 if (options & WNOHANG) {
1340 sx_xunlock(&proctree_lock);
1341 td->td_retval[0] = 0;
1342 return (0);
1343 }
1344 PROC_LOCK(q);
1345 sx_xunlock(&proctree_lock);
1346 if (q->p_flag & P_STATCHILD) {
1347 q->p_flag &= ~P_STATCHILD;
1348 error = 0;
1349 } else
1350 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
1351 PROC_UNLOCK(q);
1352 if (error)
1353 return (error);
1354 goto loop;
1355 }
1356
1357 /*
1358 * Make process 'parent' the new parent of process 'child'.
1359 * Must be called with an exclusive hold of proctree lock.
1360 */
1361 void
proc_reparent(struct proc * child,struct proc * parent)1362 proc_reparent(struct proc *child, struct proc *parent)
1363 {
1364
1365 sx_assert(&proctree_lock, SX_XLOCKED);
1366 PROC_LOCK_ASSERT(child, MA_OWNED);
1367 if (child->p_pptr == parent)
1368 return;
1369
1370 PROC_LOCK(child->p_pptr);
1371 sigqueue_take(child->p_ksi);
1372 PROC_UNLOCK(child->p_pptr);
1373 LIST_REMOVE(child, p_sibling);
1374 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1375
1376 clear_orphan(child);
1377 if (child->p_flag & P_TRACED) {
1378 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1379 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1380 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1381 p_orphan);
1382 } else {
1383 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1384 child, p_orphan);
1385 }
1386 child->p_treeflag |= P_TREE_ORPHANED;
1387 }
1388
1389 child->p_pptr = parent;
1390 }
1391