2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
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9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
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13 * modification, are permitted provided that the following conditions
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24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
42 #include "opt_ktrace.h"
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>
52 #include <sys/mutex.h>
54 #include <sys/procdesc.h>
55 #include <sys/pioctl.h>
59 #include <sys/vmmeter.h>
60 #include <sys/vnode.h>
61 #include <sys/racct.h>
62 #include <sys/resourcevar.h>
64 #include <sys/signalvar.h>
65 #include <sys/sched.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>
77 #include <sys/ktrace.h>
80 #include <security/audit/audit.h>
81 #include <security/mac/mac_framework.h>
84 #include <vm/vm_extern.h>
85 #include <vm/vm_param.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_page.h>
92 #include <sys/dtrace_bsd.h>
93 dtrace_execexit_func_t dtrace_fasttrap_exit;
96 SDT_PROVIDER_DECLARE(proc);
97 SDT_PROBE_DEFINE1(proc, , , exit, "int");
99 /* Hook for NFS teardown procedure. */
100 void (*nlminfo_release_p)(struct proc *p);
103 proc_realparent(struct proc *child)
105 struct proc *p, *parent;
107 sx_assert(&proctree_lock, SX_LOCKED);
108 if ((child->p_treeflag & P_TREE_ORPHANED) == 0)
109 return (child->p_pptr->p_pid == child->p_oppid ?
110 child->p_pptr : initproc);
111 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
112 /* Cannot use LIST_PREV(), since the list head is not known. */
113 p = __containerof(p->p_orphan.le_prev, struct proc,
115 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
116 ("missing P_ORPHAN %p", p));
118 parent = __containerof(p->p_orphan.le_prev, struct proc,
124 reaper_abandon_children(struct proc *p, bool exiting)
126 struct proc *p1, *p2, *ptmp;
128 sx_assert(&proctree_lock, SX_LOCKED);
129 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
130 if ((p->p_treeflag & P_TREE_REAPER) == 0)
133 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
134 LIST_REMOVE(p2, p_reapsibling);
136 p2->p_reapsubtree = p->p_reapsubtree;
137 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
138 if (exiting && p2->p_pptr == p) {
140 proc_reparent(p2, p1, true);
144 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
145 p->p_treeflag &= ~P_TREE_REAPER;
149 reaper_clear(struct proc *p)
154 sx_assert(&proctree_lock, SX_LOCKED);
155 LIST_REMOVE(p, p_reapsibling);
156 if (p->p_reapsubtree == 1)
159 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) {
160 if (p1->p_reapsubtree == p->p_reapsubtree) {
166 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree);
170 clear_orphan(struct proc *p)
174 sx_assert(&proctree_lock, SA_XLOCKED);
175 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
177 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
178 p1 = LIST_NEXT(p, p_orphan);
180 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
181 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
183 LIST_REMOVE(p, p_orphan);
184 p->p_treeflag &= ~P_TREE_ORPHANED;
188 * exit -- death of process.
191 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
194 exit1(td, uap->rval, 0);
199 * Exit: deallocate address space and other resources, change proc state to
200 * zombie, and unlink proc from allproc and parent's lists. Save exit status
201 * and rusage for wait(). Check for child processes and orphan them.
204 exit1(struct thread *td, int rval, int signo)
206 struct proc *p, *nq, *q, *t;
208 ksiginfo_t *ksi, *ksi1;
211 mtx_assert(&Giant, MA_NOTOWNED);
212 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
216 * XXX in case we're rebooting we just let init die in order to
217 * work around an unsolved stack overflow seen very late during
218 * shutdown on sparc64 when the gmirror worker process exists.
220 if (p == initproc && rebooting == 0) {
221 printf("init died (signal %d, exit %d)\n", signo, rval);
222 panic("Going nowhere without my init!");
226 * Deref SU mp, since the thread does not return to userspace.
228 td_softdep_cleanup(td);
231 * MUST abort all other threads before proceeding past here.
235 * First check if some other thread or external request got
236 * here before us. If so, act appropriately: exit or suspend.
237 * We must ensure that stop requests are handled before we set
240 thread_suspend_check(0);
241 while (p->p_flag & P_HADTHREADS) {
243 * Kill off the other threads. This requires
244 * some co-operation from other parts of the kernel
245 * so it may not be instantaneous. With this state set
246 * any thread entering the kernel from userspace will
247 * thread_exit() in trap(). Any thread attempting to
248 * sleep will return immediately with EINTR or EWOULDBLOCK
249 * which will hopefully force them to back out to userland
250 * freeing resources as they go. Any thread attempting
251 * to return to userland will thread_exit() from userret().
252 * thread_exit() will unsuspend us when the last of the
253 * other threads exits.
254 * If there is already a thread singler after resumption,
255 * calling thread_single will fail; in that case, we just
256 * re-check all suspension request, the thread should
257 * either be suspended there or exit.
259 if (!thread_single(p, SINGLE_EXIT))
261 * All other activity in this process is now
262 * stopped. Threading support has been turned
267 * Recheck for new stop or suspend requests which
268 * might appear while process lock was dropped in
271 thread_suspend_check(0);
273 KASSERT(p->p_numthreads == 1,
274 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
275 racct_sub(p, RACCT_NTHR, 1);
277 /* Let event handler change exit status */
282 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
283 * on our vmspace, so we should block below until they have
284 * released their reference to us. Note that if they have
285 * requested S_EXIT stops we will block here until they ack
288 _STOPEVENT(p, S_EXIT, 0);
291 * Ignore any pending request to stop due to a stop signal.
292 * Once P_WEXIT is set, future requests will be ignored as
295 p->p_flag &= ~P_STOPPED_SIG;
296 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
299 * Note that we are exiting and do another wakeup of anyone in
300 * PIOCWAIT in case they aren't listening for S_EXIT stops or
301 * decided to wait again after we told them we are exiting.
303 p->p_flag |= P_WEXIT;
307 * Wait for any processes that have a hold on our vmspace to
308 * release their reference.
310 while (p->p_lock > 0)
311 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
314 /* Drain the limit callout while we don't have the proc locked */
315 callout_drain(&p->p_limco);
319 * The Sun BSM exit token contains two components: an exit status as
320 * passed to exit(), and a return value to indicate what sort of exit
321 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
322 * what the return value is.
324 AUDIT_ARG_EXIT(rval, 0);
325 AUDIT_SYSCALL_EXIT(0, td);
328 /* Are we a task leader with peers? */
329 if (p->p_peers != NULL && p == p->p_leader) {
330 mtx_lock(&ppeers_lock);
334 kern_psignal(q, SIGKILL);
338 while (p->p_peers != NULL)
339 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
340 mtx_unlock(&ppeers_lock);
344 * Check if any loadable modules need anything done at process exit.
345 * E.g. SYSV IPC stuff.
346 * Event handler could change exit status.
347 * XXX what if one of these generates an error?
349 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
352 * If parent is waiting for us to exit or exec,
353 * P_PPWAIT is set; we will wakeup the parent below.
357 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
361 * Stop the real interval timer. If the handler is currently
362 * executing, prevent it from rearming itself and let it finish.
364 if (timevalisset(&p->p_realtimer.it_value) &&
365 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
366 timevalclear(&p->p_realtimer.it_interval);
367 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
368 KASSERT(!timevalisset(&p->p_realtimer.it_value),
369 ("realtime timer is still armed"));
374 umtx_thread_exit(td);
377 * Reset any sigio structures pointing to us as a result of
378 * F_SETOWN with our pid.
380 funsetownlst(&p->p_sigiolst);
383 * If this process has an nlminfo data area (for lockd), release it
385 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
386 (*nlminfo_release_p)(p);
389 * Close open files and release open-file table.
395 * If this thread tickled GEOM, we need to wait for the giggling to
396 * stop before we return to userland
398 if (td->td_pflags & TDP_GEOM)
402 * Remove ourself from our leader's peer list and wake our leader.
404 if (p->p_leader->p_peers != NULL) {
405 mtx_lock(&ppeers_lock);
406 if (p->p_leader->p_peers != NULL) {
408 while (q->p_peers != p)
410 q->p_peers = p->p_peers;
413 mtx_unlock(&ppeers_lock);
418 (void)acct_process(td);
424 * Release reference to text vnode
426 if (p->p_textvp != NULL) {
432 * Release our limits structure.
434 lim_free(p->p_limit);
440 * Call machine-dependent code to release any
441 * machine-dependent resources other than the address space.
442 * The address space is released by "vmspace_exitfree(p)" in
447 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
450 * Move proc from allproc queue to zombproc.
452 sx_xlock(&allproc_lock);
453 sx_xlock(&zombproc_lock);
454 LIST_REMOVE(p, p_list);
455 LIST_INSERT_HEAD(&zombproc, p, p_list);
456 sx_xunlock(&zombproc_lock);
457 sx_xunlock(&allproc_lock);
459 sx_xlock(&proctree_lock);
462 * Reparent all children processes:
463 * - traced ones to the original parent (or init if we are that parent)
466 q = LIST_FIRST(&p->p_children);
467 if (q != NULL) /* only need this if any child is S_ZOMB */
469 for (; q != NULL; q = nq) {
470 nq = LIST_NEXT(q, p_sibling);
471 ksi = ksiginfo_alloc(TRUE);
473 q->p_sigparent = SIGCHLD;
475 if (!(q->p_flag & P_TRACED)) {
476 proc_reparent(q, q->p_reaper, true);
477 if (q->p_state == PRS_ZOMBIE) {
479 * Inform reaper about the reparented
480 * zombie, since wait(2) has something
481 * new to report. Guarantee queueing
482 * of the SIGCHLD signal, similar to
483 * the _exit() behaviour, by providing
484 * our ksiginfo. Ksi is freed by the
487 if (q->p_ksi == NULL) {
490 ksiginfo_copy(q->p_ksi, ksi);
491 ksi->ksi_flags |= KSI_INS;
495 PROC_LOCK(q->p_reaper);
496 pksignal(q->p_reaper, SIGCHLD, ksi1);
497 PROC_UNLOCK(q->p_reaper);
498 } else if (q->p_pdeathsig > 0) {
500 * The child asked to received a signal
503 kern_psignal(q, q->p_pdeathsig);
507 * Traced processes are killed since their existence
508 * means someone is screwing up.
510 t = proc_realparent(q);
512 proc_reparent(q, q->p_reaper, true);
515 proc_reparent(q, t, true);
519 * Since q was found on our children list, the
520 * proc_reparent() call moved q to the orphan
521 * list due to present P_TRACED flag. Clear
522 * orphan link for q now while q is locked.
525 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
526 q->p_flag2 &= ~P2_PTRACE_FSTP;
528 FOREACH_THREAD_IN_PROC(q, tdt) {
529 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
532 kern_psignal(q, SIGKILL);
540 * Also get rid of our orphans.
542 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
544 KASSERT(q->p_oppid == p->p_pid,
545 ("orphan %p of %p has unexpected oppid %d", q, p,
547 q->p_oppid = q->p_reaper->p_pid;
550 * If we are the real parent of this process
551 * but it has been reparented to a debugger, then
552 * check if it asked for a signal when we exit.
554 if (q->p_pdeathsig > 0)
555 kern_psignal(q, q->p_pdeathsig);
556 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
563 if (SDT_PROBES_ENABLED()) {
564 int reason = CLD_EXITED;
565 if (WCOREDUMP(signo))
567 else if (WIFSIGNALED(signo))
569 SDT_PROBE1(proc, , , exit, reason);
573 /* Save exit status. */
579 * Tell the DTrace fasttrap provider about the exit if it
580 * has declared an interest.
582 if (dtrace_fasttrap_exit)
583 dtrace_fasttrap_exit(p);
587 * Notify interested parties of our demise.
589 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
592 * If this is a process with a descriptor, we may not need to deliver
593 * a signal to the parent. proctree_lock is held over
594 * procdesc_exit() to serialize concurrent calls to close() and
598 if (p->p_procdesc == NULL || procdesc_exit(p)) {
600 * Notify parent that we're gone. If parent has the
601 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
602 * notify process 1 instead (and hope it will handle this
605 PROC_LOCK(p->p_pptr);
606 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
607 if (p->p_pptr->p_sigacts->ps_flag &
608 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
611 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
614 proc_reparent(p, p->p_reaper, true);
615 p->p_sigparent = SIGCHLD;
616 PROC_LOCK(p->p_pptr);
619 * Notify parent, so in case he was wait(2)ing or
620 * executing waitpid(2) with our pid, he will
625 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
627 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
629 } else if (p->p_sigparent != 0) {
630 if (p->p_sigparent == SIGCHLD) {
632 } else { /* LINUX thread */
637 PROC_LOCK(p->p_pptr);
638 sx_xunlock(&proctree_lock);
640 if (signal_parent == 1) {
642 } else if (signal_parent == 2) {
643 kern_psignal(p->p_pptr, p->p_sigparent);
646 /* Tell the prison that we are gone. */
647 prison_proc_free(p->p_ucred->cr_prison);
650 * The state PRS_ZOMBIE prevents other proesses from sending
651 * signal to the process, to avoid memory leak, we free memory
652 * for signal queue at the time when the state is set.
654 sigqueue_flush(&p->p_sigqueue);
655 sigqueue_flush(&td->td_sigqueue);
658 * We have to wait until after acquiring all locks before
659 * changing p_state. We need to avoid all possible context
660 * switches (including ones from blocking on a mutex) while
661 * marked as a zombie. We also have to set the zombie state
662 * before we release the parent process' proc lock to avoid
663 * a lost wakeup. So, we first call wakeup, then we grab the
664 * sched lock, update the state, and release the parent process'
668 cv_broadcast(&p->p_pwait);
669 sched_exit(p->p_pptr, td);
671 p->p_state = PRS_ZOMBIE;
672 PROC_UNLOCK(p->p_pptr);
675 * Save our children's rusage information in our exit rusage.
678 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
682 * Make sure the scheduler takes this thread out of its tables etc.
683 * This will also release this thread's reference to the ucred.
684 * Other thread parts to release include pcb bits and such.
690 #ifndef _SYS_SYSPROTO_H_
699 sys_abort2(struct thread *td, struct abort2_args *uap)
701 struct proc *p = td->td_proc;
707 * Do it right now so we can log either proper call of abort2(), or
708 * note, that invalid argument was passed. 512 is big enough to
709 * handle 16 arguments' descriptions with additional comments.
711 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
713 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
714 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
716 * Since we can't return from abort2(), send SIGKILL in cases, where
717 * abort2() was called improperly
720 /* Prevent from DoSes from user-space. */
721 if (uap->nargs < 0 || uap->nargs > 16)
723 if (uap->nargs > 0) {
724 if (uap->args == NULL)
726 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
731 * Limit size of 'reason' string to 128. Will fit even when
732 * maximal number of arguments was chosen to be logged.
734 if (uap->why != NULL) {
735 error = sbuf_copyin(sb, uap->why, 128);
739 sbuf_printf(sb, "(null)");
741 if (uap->nargs > 0) {
742 sbuf_printf(sb, "(");
743 for (i = 0;i < uap->nargs; i++)
744 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
745 sbuf_printf(sb, ")");
748 * Final stage: arguments were proper, string has been
749 * successfully copied from userspace, and copying pointers
750 * from user-space succeed.
754 if (sig == SIGKILL) {
756 sbuf_printf(sb, " (Reason text inaccessible)");
760 log(LOG_INFO, "%s", sbuf_data(sb));
769 * The dirty work is handled by kern_wait().
772 owait(struct thread *td, struct owait_args *uap __unused)
776 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
778 td->td_retval[1] = status;
781 #endif /* COMPAT_43 */
784 * The dirty work is handled by kern_wait().
787 sys_wait4(struct thread *td, struct wait4_args *uap)
789 struct rusage ru, *rup;
792 if (uap->rusage != NULL)
796 error = kern_wait(td, uap->pid, &status, uap->options, rup);
797 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
798 error = copyout(&status, uap->status, sizeof(status));
799 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
800 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
805 sys_wait6(struct thread *td, struct wait6_args *uap)
807 struct __wrusage wru, *wrup;
813 idtype = uap->idtype;
816 if (uap->wrusage != NULL)
821 if (uap->info != NULL) {
823 bzero(sip, sizeof(*sip));
828 * We expect all callers of wait6() to know about WEXITED and
831 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
833 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
834 error = copyout(&status, uap->status, sizeof(status));
835 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
836 error = copyout(&wru, uap->wrusage, sizeof(wru));
837 if (uap->info != NULL && error == 0)
838 error = copyout(&si, uap->info, sizeof(si));
843 * Reap the remains of a zombie process and optionally return status and
844 * rusage. Asserts and will release both the proctree_lock and the process
845 * lock as part of its work.
848 proc_reap(struct thread *td, struct proc *p, int *status, int options)
852 sx_assert(&proctree_lock, SA_XLOCKED);
853 PROC_LOCK_ASSERT(p, MA_OWNED);
854 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
856 mtx_spin_wait_unlocked(&p->p_slock);
861 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
862 if (options & WNOWAIT) {
864 * Only poll, returning the status. Caller does not wish to
865 * release the proc struct just yet.
868 sx_xunlock(&proctree_lock);
873 sigqueue_take(p->p_ksi);
877 * If we got the child via a ptrace 'attach', we need to give it back
880 if (p->p_oppid != p->p_pptr->p_pid) {
882 t = proc_realparent(p);
886 "wait: traced child %d moved back to parent %d", p->p_pid,
888 proc_reparent(p, t, false);
890 pksignal(t, SIGCHLD, p->p_ksi);
892 cv_broadcast(&p->p_pwait);
894 sx_xunlock(&proctree_lock);
900 * Remove other references to this process to ensure we have an
901 * exclusive reference.
903 sx_xlock(&zombproc_lock);
904 LIST_REMOVE(p, p_list); /* off zombproc */
905 sx_xunlock(&zombproc_lock);
906 sx_xlock(PIDHASHLOCK(p->p_pid));
907 LIST_REMOVE(p, p_hash);
908 sx_xunlock(PIDHASHLOCK(p->p_pid));
909 LIST_REMOVE(p, p_sibling);
910 reaper_abandon_children(p, true);
912 proc_id_clear(PROC_ID_PID, p->p_pid);
917 if (p->p_procdesc != NULL)
919 sx_xunlock(&proctree_lock);
922 knlist_detach(p->p_klist);
927 * Removal from allproc list and process group list paired with
928 * PROC_LOCK which was executed during that time should guarantee
929 * nothing can reach this process anymore. As such further locking
932 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
935 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
939 * Decrement the count of procs running with this uid.
941 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
944 * Destroy resource accounting information associated with the process.
949 racct_sub(p, RACCT_NPROC, 1);
956 * Free credentials, arguments, and sigacts.
959 proc_set_cred(p, NULL);
960 pargs_drop(p->p_args);
962 sigacts_free(p->p_sigacts);
966 * Do any thread-system specific cleanups.
971 * Give vm and machine-dependent layer a chance to free anything that
972 * cpu_exit couldn't release while still running in process context.
979 KASSERT(FIRST_THREAD_IN_PROC(p),
980 ("proc_reap: no residual thread!"));
981 uma_zfree(proc_zone, p);
982 atomic_add_int(&nprocs, -1);
986 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
987 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
992 sx_assert(&proctree_lock, SA_XLOCKED);
998 if (p->p_procdesc != NULL) {
1004 if (p->p_pid != (pid_t)id) {
1010 if (p->p_pgid != (pid_t)id) {
1016 if (p->p_session->s_sid != (pid_t)id) {
1022 if (p->p_ucred->cr_uid != (uid_t)id) {
1028 if (p->p_ucred->cr_gid != (gid_t)id) {
1034 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1040 * It seems that the thread structures get zeroed out
1041 * at process exit. This makes it impossible to
1042 * support P_SETID, P_CID or P_CPUID.
1049 if (p_canwait(td, p)) {
1054 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1060 * This special case handles a kthread spawned by linux_clone
1061 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1062 * functions need to be able to distinguish between waiting
1063 * on a process and waiting on a thread. It is a thread if
1064 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1065 * signifies we want to wait for threads and not processes.
1067 if ((p->p_sigparent != SIGCHLD) ^
1068 ((options & WLINUXCLONE) != 0)) {
1073 if (siginfo != NULL) {
1074 bzero(siginfo, sizeof(*siginfo));
1075 siginfo->si_errno = 0;
1078 * SUSv4 requires that the si_signo value is always
1079 * SIGCHLD. Obey it despite the rfork(2) interface
1080 * allows to request other signal for child exit
1083 siginfo->si_signo = SIGCHLD;
1086 * This is still a rough estimate. We will fix the
1087 * cases TRAPPED, STOPPED, and CONTINUED later.
1089 if (WCOREDUMP(p->p_xsig)) {
1090 siginfo->si_code = CLD_DUMPED;
1091 siginfo->si_status = WTERMSIG(p->p_xsig);
1092 } else if (WIFSIGNALED(p->p_xsig)) {
1093 siginfo->si_code = CLD_KILLED;
1094 siginfo->si_status = WTERMSIG(p->p_xsig);
1096 siginfo->si_code = CLD_EXITED;
1097 siginfo->si_status = p->p_xexit;
1100 siginfo->si_pid = p->p_pid;
1101 siginfo->si_uid = p->p_ucred->cr_uid;
1104 * The si_addr field would be useful additional
1105 * detail, but apparently the PC value may be lost
1106 * when we reach this point. bzero() above sets
1107 * siginfo->si_addr to NULL.
1112 * There should be no reason to limit resources usage info to
1113 * exited processes only. A snapshot about any resources used
1114 * by a stopped process may be exactly what is needed.
1116 if (wrusage != NULL) {
1117 rup = &wrusage->wru_self;
1120 calcru(p, &rup->ru_utime, &rup->ru_stime);
1123 rup = &wrusage->wru_children;
1124 *rup = p->p_stats->p_cru;
1125 calccru(p, &rup->ru_utime, &rup->ru_stime);
1128 if (p->p_state == PRS_ZOMBIE && !check_only) {
1129 proc_reap(td, p, status, options);
1136 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1137 struct rusage *rusage)
1139 struct __wrusage wru, *wrup;
1145 * Translate the special pid values into the (idtype, pid)
1146 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1147 * kern_wait6() on its own.
1149 if (pid == WAIT_ANY) {
1152 } else if (pid < 0) {
1166 * For backward compatibility we implicitly add flags WEXITED
1167 * and WTRAPPED here.
1169 options |= WEXITED | WTRAPPED;
1170 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1172 *rusage = wru.wru_self;
1177 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1178 int *status, int options, int si_code)
1182 PROC_LOCK_ASSERT(p, MA_OWNED);
1183 sx_assert(&proctree_lock, SA_XLOCKED);
1184 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1185 si_code == CLD_CONTINUED);
1187 cont = si_code == CLD_CONTINUED;
1188 if ((options & WNOWAIT) == 0) {
1190 p->p_flag &= ~P_CONTINUED;
1192 p->p_flag |= P_WAITED;
1193 PROC_LOCK(td->td_proc);
1194 sigqueue_take(p->p_ksi);
1195 PROC_UNLOCK(td->td_proc);
1197 sx_xunlock(&proctree_lock);
1198 if (siginfo != NULL) {
1199 siginfo->si_code = si_code;
1200 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1203 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1205 td->td_retval[0] = p->p_pid;
1209 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1210 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1214 int error, nfound, ret;
1217 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1218 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1219 AUDIT_ARG_VALUE(options);
1223 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1225 id = (id_t)q->p_pgid;
1230 /* If we don't know the option, just return. */
1231 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1232 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1234 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1236 * We will be unable to find any matching processes,
1237 * because there are no known events to look for.
1238 * Prefer to return error instead of blocking
1245 if (q->p_flag & P_STATCHILD) {
1247 q->p_flag &= ~P_STATCHILD;
1250 sx_xlock(&proctree_lock);
1253 LIST_FOREACH(p, &q->p_children, p_sibling) {
1255 ret = proc_to_reap(td, p, idtype, id, status, options,
1256 wrusage, siginfo, 0);
1259 else if (ret != 1) {
1260 td->td_retval[0] = pid;
1265 PROC_LOCK_ASSERT(p, MA_OWNED);
1267 if ((options & WTRAPPED) != 0 &&
1268 (p->p_flag & P_TRACED) != 0) {
1271 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1272 p->p_suspcount == p->p_numthreads &&
1273 (p->p_flag & P_WAITED) == 0);
1277 "wait: returning trapped pid %d status %#x "
1278 "(xstat %d) xthread %d",
1279 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1280 p->p_xthread != NULL ?
1281 p->p_xthread->td_tid : -1);
1282 report_alive_proc(td, p, siginfo, status,
1283 options, CLD_TRAPPED);
1287 if ((options & WUNTRACED) != 0 &&
1288 (p->p_flag & P_STOPPED_SIG) != 0) {
1290 report = (p->p_suspcount == p->p_numthreads &&
1291 ((p->p_flag & P_WAITED) == 0));
1294 report_alive_proc(td, p, siginfo, status,
1295 options, CLD_STOPPED);
1299 if ((options & WCONTINUED) != 0 &&
1300 (p->p_flag & P_CONTINUED) != 0) {
1301 report_alive_proc(td, p, siginfo, status, options,
1309 * Look in the orphans list too, to allow the parent to
1310 * collect it's child exit status even if child is being
1313 * Debugger detaches from the parent upon successful
1314 * switch-over from parent to child. At this point due to
1315 * re-parenting the parent loses the child to debugger and a
1316 * wait4(2) call would report that it has no children to wait
1317 * for. By maintaining a list of orphans we allow the parent
1318 * to successfully wait until the child becomes a zombie.
1321 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1322 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1325 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1326 (int)td->td_retval[0]));
1334 sx_xunlock(&proctree_lock);
1337 if (options & WNOHANG) {
1338 sx_xunlock(&proctree_lock);
1339 td->td_retval[0] = 0;
1343 if (q->p_flag & P_STATCHILD) {
1344 q->p_flag &= ~P_STATCHILD;
1348 sx_xunlock(&proctree_lock);
1349 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1356 * Make process 'parent' the new parent of process 'child'.
1357 * Must be called with an exclusive hold of proctree lock.
1360 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1363 sx_assert(&proctree_lock, SX_XLOCKED);
1364 PROC_LOCK_ASSERT(child, MA_OWNED);
1365 if (child->p_pptr == parent)
1368 PROC_LOCK(child->p_pptr);
1369 sigqueue_take(child->p_ksi);
1370 PROC_UNLOCK(child->p_pptr);
1371 LIST_REMOVE(child, p_sibling);
1372 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1374 clear_orphan(child);
1375 if (child->p_flag & P_TRACED) {
1376 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1377 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1378 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1381 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1384 child->p_treeflag |= P_TREE_ORPHANED;
1387 child->p_pptr = parent;
1389 child->p_oppid = parent->p_pid;