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
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
42 #include "opt_compat.h"
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/capsicum.h>
49 #include <sys/eventhandler.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
53 #include <sys/mutex.h>
55 #include <sys/procdesc.h>
56 #include <sys/pioctl.h>
60 #include <sys/vmmeter.h>
61 #include <sys/vnode.h>
62 #include <sys/racct.h>
63 #include <sys/resourcevar.h>
65 #include <sys/signalvar.h>
66 #include <sys/sched.h>
68 #include <sys/syscallsubr.h>
69 #include <sys/syslog.h>
70 #include <sys/ptrace.h>
71 #include <sys/acct.h> /* for acct_process() function prototype */
72 #include <sys/filedesc.h>
78 #include <sys/ktrace.h>
81 #include <security/audit/audit.h>
82 #include <security/mac/mac_framework.h>
85 #include <vm/vm_extern.h>
86 #include <vm/vm_param.h>
88 #include <vm/vm_map.h>
89 #include <vm/vm_page.h>
91 #include <vm/vm_domain.h>
94 #include <sys/dtrace_bsd.h>
95 dtrace_execexit_func_t dtrace_fasttrap_exit;
98 SDT_PROVIDER_DECLARE(proc);
99 SDT_PROBE_DEFINE1(proc, , , exit, "int");
101 /* Hook for NFS teardown procedure. */
102 void (*nlminfo_release_p)(struct proc *p);
104 EVENTHANDLER_LIST_DECLARE(process_exit);
107 proc_realparent(struct proc *child)
109 struct proc *p, *parent;
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;
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,
124 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
125 ("missing P_ORPHAN %p", p));
127 parent = __containerof(p->p_orphan.le_prev, struct proc,
133 reaper_abandon_children(struct proc *p, bool exiting)
135 struct proc *p1, *p2, *ptmp;
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)
142 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
143 LIST_REMOVE(p2, p_reapsibling);
145 p2->p_reapsubtree = p->p_reapsubtree;
146 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
147 if (exiting && p2->p_pptr == p) {
149 proc_reparent(p2, p1);
153 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
154 p->p_treeflag &= ~P_TREE_REAPER;
158 clear_orphan(struct proc *p)
162 sx_assert(&proctree_lock, SA_XLOCKED);
163 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
165 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
166 p1 = LIST_NEXT(p, p_orphan);
168 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
169 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
171 LIST_REMOVE(p, p_orphan);
172 p->p_treeflag &= ~P_TREE_ORPHANED;
176 * exit -- death of process.
179 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
182 exit1(td, uap->rval, 0);
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.
192 exit1(struct thread *td, int rval, int signo)
194 struct proc *p, *nq, *q, *t;
196 ksiginfo_t *ksi, *ksi1;
198 mtx_assert(&Giant, MA_NOTOWNED);
199 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
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.
207 if (p == initproc && rebooting == 0) {
208 printf("init died (signal %d, exit %d)\n", signo, rval);
209 panic("Going nowhere without my init!");
213 * Deref SU mp, since the thread does not return to userspace.
215 td_softdep_cleanup(td);
218 * MUST abort all other threads before proceeding past here.
222 * First check if some other thread or external request got
223 * here before us. If so, act appropriately: exit or suspend.
224 * We must ensure that stop requests are handled before we set
227 thread_suspend_check(0);
228 while (p->p_flag & P_HADTHREADS) {
230 * Kill off the other threads. This requires
231 * some co-operation from other parts of the kernel
232 * so it may not be instantaneous. With this state set
233 * any thread entering the kernel from userspace will
234 * thread_exit() in trap(). Any thread attempting to
235 * sleep will return immediately with EINTR or EWOULDBLOCK
236 * which will hopefully force them to back out to userland
237 * freeing resources as they go. Any thread attempting
238 * to return to userland will thread_exit() from userret().
239 * thread_exit() will unsuspend us when the last of the
240 * other threads exits.
241 * If there is already a thread singler after resumption,
242 * calling thread_single will fail; in that case, we just
243 * re-check all suspension request, the thread should
244 * either be suspended there or exit.
246 if (!thread_single(p, SINGLE_EXIT))
248 * All other activity in this process is now
249 * stopped. Threading support has been turned
254 * Recheck for new stop or suspend requests which
255 * might appear while process lock was dropped in
258 thread_suspend_check(0);
260 KASSERT(p->p_numthreads == 1,
261 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
262 racct_sub(p, RACCT_NTHR, 1);
264 /* Let event handler change exit status */
269 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
270 * on our vmspace, so we should block below until they have
271 * released their reference to us. Note that if they have
272 * requested S_EXIT stops we will block here until they ack
275 _STOPEVENT(p, S_EXIT, 0);
278 * Ignore any pending request to stop due to a stop signal.
279 * Once P_WEXIT is set, future requests will be ignored as
282 p->p_flag &= ~P_STOPPED_SIG;
283 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
286 * Note that we are exiting and do another wakeup of anyone in
287 * PIOCWAIT in case they aren't listening for S_EXIT stops or
288 * decided to wait again after we told them we are exiting.
290 p->p_flag |= P_WEXIT;
294 * Wait for any processes that have a hold on our vmspace to
295 * release their reference.
297 while (p->p_lock > 0)
298 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
301 /* Drain the limit callout while we don't have the proc locked */
302 callout_drain(&p->p_limco);
306 * The Sun BSM exit token contains two components: an exit status as
307 * passed to exit(), and a return value to indicate what sort of exit
308 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
309 * what the return value is.
311 AUDIT_ARG_EXIT(rval, 0);
312 AUDIT_SYSCALL_EXIT(0, td);
315 /* Are we a task leader with peers? */
316 if (p->p_peers != NULL && p == p->p_leader) {
317 mtx_lock(&ppeers_lock);
321 kern_psignal(q, SIGKILL);
325 while (p->p_peers != NULL)
326 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
327 mtx_unlock(&ppeers_lock);
331 * Check if any loadable modules need anything done at process exit.
332 * E.g. SYSV IPC stuff.
333 * Event handler could change exit status.
334 * XXX what if one of these generates an error?
336 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
339 * If parent is waiting for us to exit or exec,
340 * P_PPWAIT is set; we will wakeup the parent below.
344 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
348 * Stop the real interval timer. If the handler is currently
349 * executing, prevent it from rearming itself and let it finish.
351 if (timevalisset(&p->p_realtimer.it_value) &&
352 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
353 timevalclear(&p->p_realtimer.it_interval);
354 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
355 KASSERT(!timevalisset(&p->p_realtimer.it_value),
356 ("realtime timer is still armed"));
361 umtx_thread_exit(td);
364 * Reset any sigio structures pointing to us as a result of
365 * F_SETOWN with our pid.
367 funsetownlst(&p->p_sigiolst);
370 * If this process has an nlminfo data area (for lockd), release it
372 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
373 (*nlminfo_release_p)(p);
376 * Close open files and release open-file table.
382 * If this thread tickled GEOM, we need to wait for the giggling to
383 * stop before we return to userland
385 if (td->td_pflags & TDP_GEOM)
389 * Remove ourself from our leader's peer list and wake our leader.
391 if (p->p_leader->p_peers != NULL) {
392 mtx_lock(&ppeers_lock);
393 if (p->p_leader->p_peers != NULL) {
395 while (q->p_peers != p)
397 q->p_peers = p->p_peers;
400 mtx_unlock(&ppeers_lock);
405 (void)acct_process(td);
411 * Release reference to text vnode
413 if (p->p_textvp != NULL) {
419 * Release our limits structure.
421 lim_free(p->p_limit);
427 * Remove proc from allproc queue and pidhash chain.
428 * Place onto zombproc. Unlink from parent's child list.
430 sx_xlock(&allproc_lock);
431 LIST_REMOVE(p, p_list);
432 LIST_INSERT_HEAD(&zombproc, p, p_list);
433 LIST_REMOVE(p, p_hash);
434 sx_xunlock(&allproc_lock);
437 * Call machine-dependent code to release any
438 * machine-dependent resources other than the address space.
439 * The address space is released by "vmspace_exitfree(p)" in
444 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
447 * Reparent all children processes:
448 * - traced ones to the original parent (or init if we are that parent)
451 sx_xlock(&proctree_lock);
452 q = LIST_FIRST(&p->p_children);
453 if (q != NULL) /* only need this if any child is S_ZOMB */
455 for (; q != NULL; q = nq) {
456 nq = LIST_NEXT(q, p_sibling);
457 ksi = ksiginfo_alloc(TRUE);
459 q->p_sigparent = SIGCHLD;
461 if (!(q->p_flag & P_TRACED)) {
462 proc_reparent(q, q->p_reaper);
463 if (q->p_state == PRS_ZOMBIE) {
465 * Inform reaper about the reparented
466 * zombie, since wait(2) has something
467 * new to report. Guarantee queueing
468 * of the SIGCHLD signal, similar to
469 * the _exit() behaviour, by providing
470 * our ksiginfo. Ksi is freed by the
473 if (q->p_ksi == NULL) {
476 ksiginfo_copy(q->p_ksi, ksi);
477 ksi->ksi_flags |= KSI_INS;
481 PROC_LOCK(q->p_reaper);
482 pksignal(q->p_reaper, SIGCHLD, ksi1);
483 PROC_UNLOCK(q->p_reaper);
487 * Traced processes are killed since their existence
488 * means someone is screwing up.
490 t = proc_realparent(q);
492 proc_reparent(q, q->p_reaper);
499 * Since q was found on our children list, the
500 * proc_reparent() call moved q to the orphan
501 * list due to present P_TRACED flag. Clear
502 * orphan link for q now while q is locked.
505 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
506 q->p_flag2 &= ~P2_PTRACE_FSTP;
508 FOREACH_THREAD_IN_PROC(q, tdt) {
509 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
512 kern_psignal(q, SIGKILL);
520 * Also get rid of our orphans.
522 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
524 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
530 /* Save exit status. */
534 /* Tell the prison that we are gone. */
535 prison_proc_free(p->p_ucred->cr_prison);
539 * Tell the DTrace fasttrap provider about the exit if it
540 * has declared an interest.
542 if (dtrace_fasttrap_exit)
543 dtrace_fasttrap_exit(p);
547 * Notify interested parties of our demise.
549 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
552 int reason = CLD_EXITED;
553 if (WCOREDUMP(signo))
555 else if (WIFSIGNALED(signo))
557 SDT_PROBE1(proc, , , exit, reason);
561 * If this is a process with a descriptor, we may not need to deliver
562 * a signal to the parent. proctree_lock is held over
563 * procdesc_exit() to serialize concurrent calls to close() and
566 if (p->p_procdesc == NULL || procdesc_exit(p)) {
568 * Notify parent that we're gone. If parent has the
569 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
570 * notify process 1 instead (and hope it will handle this
573 PROC_LOCK(p->p_pptr);
574 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
575 if (p->p_pptr->p_sigacts->ps_flag &
576 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
579 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
582 proc_reparent(p, p->p_reaper);
583 p->p_sigparent = SIGCHLD;
584 PROC_LOCK(p->p_pptr);
587 * Notify parent, so in case he was wait(2)ing or
588 * executing waitpid(2) with our pid, he will
593 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
595 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc)
597 else if (p->p_sigparent != 0) {
598 if (p->p_sigparent == SIGCHLD)
600 else /* LINUX thread */
601 kern_psignal(p->p_pptr, p->p_sigparent);
604 PROC_LOCK(p->p_pptr);
605 sx_xunlock(&proctree_lock);
608 * The state PRS_ZOMBIE prevents other proesses from sending
609 * signal to the process, to avoid memory leak, we free memory
610 * for signal queue at the time when the state is set.
612 sigqueue_flush(&p->p_sigqueue);
613 sigqueue_flush(&td->td_sigqueue);
616 * We have to wait until after acquiring all locks before
617 * changing p_state. We need to avoid all possible context
618 * switches (including ones from blocking on a mutex) while
619 * marked as a zombie. We also have to set the zombie state
620 * before we release the parent process' proc lock to avoid
621 * a lost wakeup. So, we first call wakeup, then we grab the
622 * sched lock, update the state, and release the parent process'
626 cv_broadcast(&p->p_pwait);
627 sched_exit(p->p_pptr, td);
629 p->p_state = PRS_ZOMBIE;
630 PROC_UNLOCK(p->p_pptr);
633 * Save our children's rusage information in our exit rusage.
636 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
640 * Make sure the scheduler takes this thread out of its tables etc.
641 * This will also release this thread's reference to the ucred.
642 * Other thread parts to release include pcb bits and such.
648 #ifndef _SYS_SYSPROTO_H_
657 sys_abort2(struct thread *td, struct abort2_args *uap)
659 struct proc *p = td->td_proc;
665 * Do it right now so we can log either proper call of abort2(), or
666 * note, that invalid argument was passed. 512 is big enough to
667 * handle 16 arguments' descriptions with additional comments.
669 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
671 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
672 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
674 * Since we can't return from abort2(), send SIGKILL in cases, where
675 * abort2() was called improperly
678 /* Prevent from DoSes from user-space. */
679 if (uap->nargs < 0 || uap->nargs > 16)
681 if (uap->nargs > 0) {
682 if (uap->args == NULL)
684 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
689 * Limit size of 'reason' string to 128. Will fit even when
690 * maximal number of arguments was chosen to be logged.
692 if (uap->why != NULL) {
693 error = sbuf_copyin(sb, uap->why, 128);
697 sbuf_printf(sb, "(null)");
699 if (uap->nargs > 0) {
700 sbuf_printf(sb, "(");
701 for (i = 0;i < uap->nargs; i++)
702 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
703 sbuf_printf(sb, ")");
706 * Final stage: arguments were proper, string has been
707 * successfully copied from userspace, and copying pointers
708 * from user-space succeed.
712 if (sig == SIGKILL) {
714 sbuf_printf(sb, " (Reason text inaccessible)");
718 log(LOG_INFO, "%s", sbuf_data(sb));
727 * The dirty work is handled by kern_wait().
730 owait(struct thread *td, struct owait_args *uap __unused)
734 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
736 td->td_retval[1] = status;
739 #endif /* COMPAT_43 */
742 * The dirty work is handled by kern_wait().
745 sys_wait4(struct thread *td, struct wait4_args *uap)
747 struct rusage ru, *rup;
750 if (uap->rusage != NULL)
754 error = kern_wait(td, uap->pid, &status, uap->options, rup);
755 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
756 error = copyout(&status, uap->status, sizeof(status));
757 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
758 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
763 sys_wait6(struct thread *td, struct wait6_args *uap)
765 struct __wrusage wru, *wrup;
771 idtype = uap->idtype;
774 if (uap->wrusage != NULL)
779 if (uap->info != NULL) {
781 bzero(sip, sizeof(*sip));
786 * We expect all callers of wait6() to know about WEXITED and
789 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
791 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
792 error = copyout(&status, uap->status, sizeof(status));
793 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
794 error = copyout(&wru, uap->wrusage, sizeof(wru));
795 if (uap->info != NULL && error == 0)
796 error = copyout(&si, uap->info, sizeof(si));
801 * Reap the remains of a zombie process and optionally return status and
802 * rusage. Asserts and will release both the proctree_lock and the process
803 * lock as part of its work.
806 proc_reap(struct thread *td, struct proc *p, int *status, int options)
810 sx_assert(&proctree_lock, SA_XLOCKED);
811 PROC_LOCK_ASSERT(p, MA_OWNED);
812 PROC_SLOCK_ASSERT(p, MA_OWNED);
813 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
819 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
820 if (options & WNOWAIT) {
822 * Only poll, returning the status. Caller does not wish to
823 * release the proc struct just yet.
826 sx_xunlock(&proctree_lock);
831 sigqueue_take(p->p_ksi);
835 * If we got the child via a ptrace 'attach', we need to give it back
838 if (p->p_oppid != 0 && p->p_oppid != p->p_pptr->p_pid) {
840 t = proc_realparent(p);
844 "wait: traced child %d moved back to parent %d", p->p_pid,
849 pksignal(t, SIGCHLD, p->p_ksi);
851 cv_broadcast(&p->p_pwait);
853 sx_xunlock(&proctree_lock);
860 * Remove other references to this process to ensure we have an
861 * exclusive reference.
863 sx_xlock(&allproc_lock);
864 LIST_REMOVE(p, p_list); /* off zombproc */
865 sx_xunlock(&allproc_lock);
866 LIST_REMOVE(p, p_sibling);
867 reaper_abandon_children(p, true);
868 LIST_REMOVE(p, p_reapsibling);
873 if (p->p_procdesc != NULL)
875 sx_xunlock(&proctree_lock);
878 knlist_detach(p->p_klist);
883 * Removal from allproc list and process group list paired with
884 * PROC_LOCK which was executed during that time should guarantee
885 * nothing can reach this process anymore. As such further locking
888 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
891 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
895 * Decrement the count of procs running with this uid.
897 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
900 * Destroy resource accounting information associated with the process.
905 racct_sub(p, RACCT_NPROC, 1);
912 * Free credentials, arguments, and sigacts.
915 proc_set_cred(p, NULL);
916 pargs_drop(p->p_args);
918 sigacts_free(p->p_sigacts);
922 * Do any thread-system specific cleanups.
927 * Give vm and machine-dependent layer a chance to free anything that
928 * cpu_exit couldn't release while still running in process context.
935 * Free any domain policy that's still hiding around.
937 vm_domain_policy_cleanup(&p->p_vm_dom_policy);
939 KASSERT(FIRST_THREAD_IN_PROC(p),
940 ("proc_reap: no residual thread!"));
941 uma_zfree(proc_zone, p);
942 atomic_add_int(&nprocs, -1);
946 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
947 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
952 sx_assert(&proctree_lock, SA_XLOCKED);
958 if (p->p_procdesc != NULL) {
964 if (p->p_pid != (pid_t)id) {
970 if (p->p_pgid != (pid_t)id) {
976 if (p->p_session->s_sid != (pid_t)id) {
982 if (p->p_ucred->cr_uid != (uid_t)id) {
988 if (p->p_ucred->cr_gid != (gid_t)id) {
994 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1000 * It seems that the thread structures get zeroed out
1001 * at process exit. This makes it impossible to
1002 * support P_SETID, P_CID or P_CPUID.
1009 if (p_canwait(td, p)) {
1014 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1020 * This special case handles a kthread spawned by linux_clone
1021 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1022 * functions need to be able to distinguish between waiting
1023 * on a process and waiting on a thread. It is a thread if
1024 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1025 * signifies we want to wait for threads and not processes.
1027 if ((p->p_sigparent != SIGCHLD) ^
1028 ((options & WLINUXCLONE) != 0)) {
1033 if (siginfo != NULL) {
1034 bzero(siginfo, sizeof(*siginfo));
1035 siginfo->si_errno = 0;
1038 * SUSv4 requires that the si_signo value is always
1039 * SIGCHLD. Obey it despite the rfork(2) interface
1040 * allows to request other signal for child exit
1043 siginfo->si_signo = SIGCHLD;
1046 * This is still a rough estimate. We will fix the
1047 * cases TRAPPED, STOPPED, and CONTINUED later.
1049 if (WCOREDUMP(p->p_xsig)) {
1050 siginfo->si_code = CLD_DUMPED;
1051 siginfo->si_status = WTERMSIG(p->p_xsig);
1052 } else if (WIFSIGNALED(p->p_xsig)) {
1053 siginfo->si_code = CLD_KILLED;
1054 siginfo->si_status = WTERMSIG(p->p_xsig);
1056 siginfo->si_code = CLD_EXITED;
1057 siginfo->si_status = p->p_xexit;
1060 siginfo->si_pid = p->p_pid;
1061 siginfo->si_uid = p->p_ucred->cr_uid;
1064 * The si_addr field would be useful additional
1065 * detail, but apparently the PC value may be lost
1066 * when we reach this point. bzero() above sets
1067 * siginfo->si_addr to NULL.
1072 * There should be no reason to limit resources usage info to
1073 * exited processes only. A snapshot about any resources used
1074 * by a stopped process may be exactly what is needed.
1076 if (wrusage != NULL) {
1077 rup = &wrusage->wru_self;
1080 calcru(p, &rup->ru_utime, &rup->ru_stime);
1083 rup = &wrusage->wru_children;
1084 *rup = p->p_stats->p_cru;
1085 calccru(p, &rup->ru_utime, &rup->ru_stime);
1088 if (p->p_state == PRS_ZOMBIE && !check_only) {
1090 proc_reap(td, p, status, options);
1097 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1098 struct rusage *rusage)
1100 struct __wrusage wru, *wrup;
1106 * Translate the special pid values into the (idtype, pid)
1107 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1108 * kern_wait6() on its own.
1110 if (pid == WAIT_ANY) {
1113 } else if (pid < 0) {
1127 * For backward compatibility we implicitly add flags WEXITED
1128 * and WTRAPPED here.
1130 options |= WEXITED | WTRAPPED;
1131 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1133 *rusage = wru.wru_self;
1138 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1139 int *status, int options, int si_code)
1143 PROC_LOCK_ASSERT(p, MA_OWNED);
1144 sx_assert(&proctree_lock, SA_XLOCKED);
1145 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1146 si_code == CLD_CONTINUED);
1148 cont = si_code == CLD_CONTINUED;
1149 if ((options & WNOWAIT) == 0) {
1151 p->p_flag &= ~P_CONTINUED;
1153 p->p_flag |= P_WAITED;
1154 PROC_LOCK(td->td_proc);
1155 sigqueue_take(p->p_ksi);
1156 PROC_UNLOCK(td->td_proc);
1158 sx_xunlock(&proctree_lock);
1159 if (siginfo != NULL) {
1160 siginfo->si_code = si_code;
1161 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1164 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1166 td->td_retval[0] = p->p_pid;
1170 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1171 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1175 int error, nfound, ret;
1177 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1178 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1179 AUDIT_ARG_VALUE(options);
1183 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1185 id = (id_t)q->p_pgid;
1190 /* If we don't know the option, just return. */
1191 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1192 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1194 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1196 * We will be unable to find any matching processes,
1197 * because there are no known events to look for.
1198 * Prefer to return error instead of blocking
1205 if (q->p_flag & P_STATCHILD) {
1207 q->p_flag &= ~P_STATCHILD;
1211 sx_xlock(&proctree_lock);
1212 LIST_FOREACH(p, &q->p_children, p_sibling) {
1214 ret = proc_to_reap(td, p, idtype, id, status, options,
1215 wrusage, siginfo, 0);
1221 td->td_retval[0] = pid;
1225 PROC_LOCK_ASSERT(p, MA_OWNED);
1227 if ((options & (WTRAPPED | WUNTRACED)) != 0)
1230 if ((options & WTRAPPED) != 0 &&
1231 (p->p_flag & P_TRACED) != 0 &&
1232 (p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) != 0 &&
1233 p->p_suspcount == p->p_numthreads &&
1234 (p->p_flag & P_WAITED) == 0) {
1237 "wait: returning trapped pid %d status %#x "
1238 "(xstat %d) xthread %d",
1239 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1240 p->p_xthread != NULL ?
1241 p->p_xthread->td_tid : -1);
1242 report_alive_proc(td, p, siginfo, status, options,
1246 if ((options & WUNTRACED) != 0 &&
1247 (p->p_flag & P_STOPPED_SIG) != 0 &&
1248 p->p_suspcount == p->p_numthreads &&
1249 (p->p_flag & P_WAITED) == 0) {
1251 report_alive_proc(td, p, siginfo, status, options,
1255 if ((options & (WTRAPPED | WUNTRACED)) != 0)
1257 if ((options & WCONTINUED) != 0 &&
1258 (p->p_flag & P_CONTINUED) != 0) {
1259 report_alive_proc(td, p, siginfo, status, options,
1267 * Look in the orphans list too, to allow the parent to
1268 * collect it's child exit status even if child is being
1271 * Debugger detaches from the parent upon successful
1272 * switch-over from parent to child. At this point due to
1273 * re-parenting the parent loses the child to debugger and a
1274 * wait4(2) call would report that it has no children to wait
1275 * for. By maintaining a list of orphans we allow the parent
1276 * to successfully wait until the child becomes a zombie.
1279 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1280 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1283 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1284 (int)td->td_retval[0]));
1292 sx_xunlock(&proctree_lock);
1295 if (options & WNOHANG) {
1296 sx_xunlock(&proctree_lock);
1297 td->td_retval[0] = 0;
1301 sx_xunlock(&proctree_lock);
1302 if (q->p_flag & P_STATCHILD) {
1303 q->p_flag &= ~P_STATCHILD;
1306 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
1314 * Make process 'parent' the new parent of process 'child'.
1315 * Must be called with an exclusive hold of proctree lock.
1318 proc_reparent(struct proc *child, struct proc *parent)
1321 sx_assert(&proctree_lock, SX_XLOCKED);
1322 PROC_LOCK_ASSERT(child, MA_OWNED);
1323 if (child->p_pptr == parent)
1326 PROC_LOCK(child->p_pptr);
1327 sigqueue_take(child->p_ksi);
1328 PROC_UNLOCK(child->p_pptr);
1329 LIST_REMOVE(child, p_sibling);
1330 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1332 clear_orphan(child);
1333 if (child->p_flag & P_TRACED) {
1334 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1335 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1336 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1339 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1342 child->p_treeflag |= P_TREE_ORPHANED;
1345 child->p_pptr = parent;