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.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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
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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.
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
34 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "opt_compat.h"
41 #include "opt_kdtrace.h"
42 #include "opt_ktrace.h"
43 #include "opt_procdesc.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/capability.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>
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, kernel, , 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 if (child->p_oppid == 0 ||
110 child->p_pptr->p_pid == child->p_oppid)
111 parent = child->p_pptr;
116 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
117 /* Cannot use LIST_PREV(), since the list head is not known. */
118 p = __containerof(p->p_orphan.le_prev, struct proc,
120 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
121 ("missing P_ORPHAN %p", p));
123 parent = __containerof(p->p_orphan.le_prev, struct proc,
129 reaper_abandon_children(struct proc *p, bool exiting)
131 struct proc *p1, *p2, *ptmp;
133 sx_assert(&proctree_lock, SX_LOCKED);
134 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
135 if ((p->p_treeflag & P_TREE_REAPER) == 0)
138 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
139 LIST_REMOVE(p2, p_reapsibling);
141 p2->p_reapsubtree = p->p_reapsubtree;
142 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
143 if (exiting && p2->p_pptr == p) {
145 proc_reparent(p2, p1);
149 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
150 p->p_treeflag &= ~P_TREE_REAPER;
154 clear_orphan(struct proc *p)
158 sx_assert(&proctree_lock, SA_XLOCKED);
159 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
161 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
162 p1 = LIST_NEXT(p, p_orphan);
164 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
165 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
167 LIST_REMOVE(p, p_orphan);
168 p->p_treeflag &= ~P_TREE_ORPHANED;
172 * exit -- death of process.
175 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
178 exit1(td, W_EXITCODE(uap->rval, 0));
183 * Exit: deallocate address space and other resources, change proc state to
184 * zombie, and unlink proc from allproc and parent's lists. Save exit status
185 * and rusage for wait(). Check for child processes and orphan them.
188 exit1(struct thread *td, int rv)
190 struct proc *p, *nq, *q, *t;
192 struct vnode *ttyvp = NULL;
194 mtx_assert(&Giant, MA_NOTOWNED);
198 * XXX in case we're rebooting we just let init die in order to
199 * work around an unsolved stack overflow seen very late during
200 * shutdown on sparc64 when the gmirror worker process exists.
202 if (p == initproc && rebooting == 0) {
203 printf("init died (signal %d, exit %d)\n",
204 WTERMSIG(rv), WEXITSTATUS(rv));
205 panic("Going nowhere without my init!");
209 * MUST abort all other threads before proceeding past here.
213 * First check if some other thread or external request got
214 * here before us. If so, act appropriately: exit or suspend.
215 * We must ensure that stop requests are handled before we set
218 thread_suspend_check(0);
219 while (p->p_flag & P_HADTHREADS) {
221 * Kill off the other threads. This requires
222 * some co-operation from other parts of the kernel
223 * so it may not be instantaneous. With this state set
224 * any thread entering the kernel from userspace will
225 * thread_exit() in trap(). Any thread attempting to
226 * sleep will return immediately with EINTR or EWOULDBLOCK
227 * which will hopefully force them to back out to userland
228 * freeing resources as they go. Any thread attempting
229 * to return to userland will thread_exit() from userret().
230 * thread_exit() will unsuspend us when the last of the
231 * other threads exits.
232 * If there is already a thread singler after resumption,
233 * calling thread_single will fail; in that case, we just
234 * re-check all suspension request, the thread should
235 * either be suspended there or exit.
237 if (!thread_single(p, SINGLE_EXIT))
239 * All other activity in this process is now
240 * stopped. Threading support has been turned
245 * Recheck for new stop or suspend requests which
246 * might appear while process lock was dropped in
249 thread_suspend_check(0);
251 KASSERT(p->p_numthreads == 1,
252 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
253 racct_sub(p, RACCT_NTHR, 1);
255 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
256 * on our vmspace, so we should block below until they have
257 * released their reference to us. Note that if they have
258 * requested S_EXIT stops we will block here until they ack
261 _STOPEVENT(p, S_EXIT, rv);
264 * Ignore any pending request to stop due to a stop signal.
265 * Once P_WEXIT is set, future requests will be ignored as
268 p->p_flag &= ~P_STOPPED_SIG;
269 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
272 * Note that we are exiting and do another wakeup of anyone in
273 * PIOCWAIT in case they aren't listening for S_EXIT stops or
274 * decided to wait again after we told them we are exiting.
276 p->p_flag |= P_WEXIT;
280 * Wait for any processes that have a hold on our vmspace to
281 * release their reference.
283 while (p->p_lock > 0)
284 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
286 p->p_xstat = rv; /* Let event handler change exit status */
288 /* Drain the limit callout while we don't have the proc locked */
289 callout_drain(&p->p_limco);
293 * The Sun BSM exit token contains two components: an exit status as
294 * passed to exit(), and a return value to indicate what sort of exit
295 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
296 * what the return value is.
298 AUDIT_ARG_EXIT(WEXITSTATUS(rv), 0);
299 AUDIT_SYSCALL_EXIT(0, td);
302 /* Are we a task leader? */
303 if (p == p->p_leader) {
304 mtx_lock(&ppeers_lock);
308 kern_psignal(q, SIGKILL);
312 while (p->p_peers != NULL)
313 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
314 mtx_unlock(&ppeers_lock);
318 * Check if any loadable modules need anything done at process exit.
319 * E.g. SYSV IPC stuff
320 * XXX what if one of these generates an error?
322 EVENTHANDLER_INVOKE(process_exit, p);
325 * If parent is waiting for us to exit or exec,
326 * P_PPWAIT is set; we will wakeup the parent below.
329 rv = p->p_xstat; /* Event handler could change exit status */
331 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
334 * Stop the real interval timer. If the handler is currently
335 * executing, prevent it from rearming itself and let it finish.
337 if (timevalisset(&p->p_realtimer.it_value) &&
338 callout_stop(&p->p_itcallout) == 0) {
339 timevalclear(&p->p_realtimer.it_interval);
340 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
341 KASSERT(!timevalisset(&p->p_realtimer.it_value),
342 ("realtime timer is still armed"));
347 * Reset any sigio structures pointing to us as a result of
348 * F_SETOWN with our pid.
350 funsetownlst(&p->p_sigiolst);
353 * If this process has an nlminfo data area (for lockd), release it
355 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
356 (*nlminfo_release_p)(p);
359 * Close open files and release open-file table.
365 * If this thread tickled GEOM, we need to wait for the giggling to
366 * stop before we return to userland
368 if (td->td_pflags & TDP_GEOM)
372 * Remove ourself from our leader's peer list and wake our leader.
374 mtx_lock(&ppeers_lock);
375 if (p->p_leader->p_peers) {
377 while (q->p_peers != p)
379 q->p_peers = p->p_peers;
382 mtx_unlock(&ppeers_lock);
386 sx_xlock(&proctree_lock);
387 if (SESS_LEADER(p)) {
388 struct session *sp = p->p_session;
392 * s_ttyp is not zero'd; we use this to indicate that
393 * the session once had a controlling terminal. (for
394 * logging and informational purposes)
405 * Signal foreground pgrp and revoke access to
406 * controlling terminal if it has not been revoked
409 * Because the TTY may have been revoked in the mean
410 * time and could already have a new session associated
411 * with it, make sure we don't send a SIGHUP to a
412 * foreground process group that does not belong to this
418 if (tp->t_session == sp)
419 tty_signal_pgrp(tp, SIGHUP);
424 sx_xunlock(&proctree_lock);
425 if (vn_lock(ttyvp, LK_EXCLUSIVE) == 0) {
426 VOP_REVOKE(ttyvp, REVOKEALL);
427 VOP_UNLOCK(ttyvp, 0);
429 sx_xlock(&proctree_lock);
432 fixjobc(p, p->p_pgrp, 0);
433 sx_xunlock(&proctree_lock);
434 (void)acct_process(td);
436 /* Release the TTY now we've unlocked everything. */
443 * Release reference to text vnode
445 if (p->p_textvp != NULL) {
451 * Release our limits structure.
453 lim_free(p->p_limit);
459 * Remove proc from allproc queue and pidhash chain.
460 * Place onto zombproc. Unlink from parent's child list.
462 sx_xlock(&allproc_lock);
463 LIST_REMOVE(p, p_list);
464 LIST_INSERT_HEAD(&zombproc, p, p_list);
465 LIST_REMOVE(p, p_hash);
466 sx_xunlock(&allproc_lock);
469 * Call machine-dependent code to release any
470 * machine-dependent resources other than the address space.
471 * The address space is released by "vmspace_exitfree(p)" in
476 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
479 * Reparent all children processes:
480 * - traced ones to the original parent (or init if we are that parent)
483 sx_xlock(&proctree_lock);
484 q = LIST_FIRST(&p->p_children);
485 if (q != NULL) /* only need this if any child is S_ZOMB */
487 for (; q != NULL; q = nq) {
488 nq = LIST_NEXT(q, p_sibling);
490 q->p_sigparent = SIGCHLD;
492 if (!(q->p_flag & P_TRACED)) {
493 proc_reparent(q, q->p_reaper);
496 * Traced processes are killed since their existence
497 * means someone is screwing up.
499 t = proc_realparent(q);
501 proc_reparent(q, q->p_reaper);
508 * Since q was found on our children list, the
509 * proc_reparent() call moved q to the orphan
510 * list due to present P_TRACED flag. Clear
511 * orphan link for q now while q is locked.
514 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
515 FOREACH_THREAD_IN_PROC(q, tdt)
516 tdt->td_dbgflags &= ~TDB_SUSPEND;
517 kern_psignal(q, SIGKILL);
523 * Also get rid of our orphans.
525 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
531 /* Save exit status. */
535 /* Tell the prison that we are gone. */
536 prison_proc_free(p->p_ucred->cr_prison);
540 * Tell the DTrace fasttrap provider about the exit if it
541 * has declared an interest.
543 if (dtrace_fasttrap_exit)
544 dtrace_fasttrap_exit(p);
548 * Notify interested parties of our demise.
550 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT);
553 int reason = CLD_EXITED;
556 else if (WIFSIGNALED(rv))
558 SDT_PROBE(proc, kernel, , exit, reason, 0, 0, 0, 0);
562 * Just delete all entries in the p_klist. At this point we won't
563 * report any more events, and there are nasty race conditions that
564 * can beat us if we don't.
566 knlist_clear(&p->p_klist, 1);
569 * If this is a process with a descriptor, we may not need to deliver
570 * a signal to the parent. proctree_lock is held over
571 * procdesc_exit() to serialize concurrent calls to close() and
575 if (p->p_procdesc == NULL || procdesc_exit(p)) {
578 * Notify parent that we're gone. If parent has the
579 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
580 * notify process 1 instead (and hope it will handle this
583 PROC_LOCK(p->p_pptr);
584 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
585 if (p->p_pptr->p_sigacts->ps_flag &
586 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
589 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
592 proc_reparent(p, p->p_reaper);
593 p->p_sigparent = SIGCHLD;
594 PROC_LOCK(p->p_pptr);
597 * Notify parent, so in case he was wait(2)ing or
598 * executing waitpid(2) with our pid, he will
603 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
605 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc)
607 else if (p->p_sigparent != 0) {
608 if (p->p_sigparent == SIGCHLD)
610 else /* LINUX thread */
611 kern_psignal(p->p_pptr, p->p_sigparent);
615 PROC_LOCK(p->p_pptr);
617 sx_xunlock(&proctree_lock);
620 * The state PRS_ZOMBIE prevents other proesses from sending
621 * signal to the process, to avoid memory leak, we free memory
622 * for signal queue at the time when the state is set.
624 sigqueue_flush(&p->p_sigqueue);
625 sigqueue_flush(&td->td_sigqueue);
628 * We have to wait until after acquiring all locks before
629 * changing p_state. We need to avoid all possible context
630 * switches (including ones from blocking on a mutex) while
631 * marked as a zombie. We also have to set the zombie state
632 * before we release the parent process' proc lock to avoid
633 * a lost wakeup. So, we first call wakeup, then we grab the
634 * sched lock, update the state, and release the parent process'
638 cv_broadcast(&p->p_pwait);
639 sched_exit(p->p_pptr, td);
641 p->p_state = PRS_ZOMBIE;
642 PROC_UNLOCK(p->p_pptr);
645 * Hopefully no one will try to deliver a signal to the process this
648 knlist_destroy(&p->p_klist);
651 * Save our children's rusage information in our exit rusage.
653 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
656 * Make sure the scheduler takes this thread out of its tables etc.
657 * This will also release this thread's reference to the ucred.
658 * Other thread parts to release include pcb bits and such.
664 #ifndef _SYS_SYSPROTO_H_
673 sys_abort2(struct thread *td, struct abort2_args *uap)
675 struct proc *p = td->td_proc;
681 * Do it right now so we can log either proper call of abort2(), or
682 * note, that invalid argument was passed. 512 is big enough to
683 * handle 16 arguments' descriptions with additional comments.
685 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
687 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
688 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
690 * Since we can't return from abort2(), send SIGKILL in cases, where
691 * abort2() was called improperly
694 /* Prevent from DoSes from user-space. */
695 if (uap->nargs < 0 || uap->nargs > 16)
697 if (uap->nargs > 0) {
698 if (uap->args == NULL)
700 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
705 * Limit size of 'reason' string to 128. Will fit even when
706 * maximal number of arguments was chosen to be logged.
708 if (uap->why != NULL) {
709 error = sbuf_copyin(sb, uap->why, 128);
713 sbuf_printf(sb, "(null)");
715 if (uap->nargs > 0) {
716 sbuf_printf(sb, "(");
717 for (i = 0;i < uap->nargs; i++)
718 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
719 sbuf_printf(sb, ")");
722 * Final stage: arguments were proper, string has been
723 * successfully copied from userspace, and copying pointers
724 * from user-space succeed.
728 if (sig == SIGKILL) {
730 sbuf_printf(sb, " (Reason text inaccessible)");
734 log(LOG_INFO, "%s", sbuf_data(sb));
736 exit1(td, W_EXITCODE(0, sig));
743 * The dirty work is handled by kern_wait().
746 owait(struct thread *td, struct owait_args *uap __unused)
750 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
752 td->td_retval[1] = status;
755 #endif /* COMPAT_43 */
758 * The dirty work is handled by kern_wait().
761 sys_wait4(struct thread *td, struct wait4_args *uap)
763 struct rusage ru, *rup;
766 if (uap->rusage != NULL)
770 error = kern_wait(td, uap->pid, &status, uap->options, rup);
771 if (uap->status != NULL && error == 0)
772 error = copyout(&status, uap->status, sizeof(status));
773 if (uap->rusage != NULL && error == 0)
774 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
779 sys_wait6(struct thread *td, struct wait6_args *uap)
781 struct __wrusage wru, *wrup;
787 idtype = uap->idtype;
790 if (uap->wrusage != NULL)
795 if (uap->info != NULL) {
797 bzero(sip, sizeof(*sip));
802 * We expect all callers of wait6() to know about WEXITED and
805 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
807 if (uap->status != NULL && error == 0)
808 error = copyout(&status, uap->status, sizeof(status));
809 if (uap->wrusage != NULL && error == 0)
810 error = copyout(&wru, uap->wrusage, sizeof(wru));
811 if (uap->info != NULL && error == 0)
812 error = copyout(&si, uap->info, sizeof(si));
817 * Reap the remains of a zombie process and optionally return status and
818 * rusage. Asserts and will release both the proctree_lock and the process
819 * lock as part of its work.
822 proc_reap(struct thread *td, struct proc *p, int *status, int options)
826 sx_assert(&proctree_lock, SA_XLOCKED);
827 PROC_LOCK_ASSERT(p, MA_OWNED);
828 PROC_SLOCK_ASSERT(p, MA_OWNED);
829 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
834 td->td_retval[0] = p->p_pid;
836 *status = p->p_xstat; /* convert to int */
837 if (options & WNOWAIT) {
839 * Only poll, returning the status. Caller does not wish to
840 * release the proc struct just yet.
843 sx_xunlock(&proctree_lock);
848 sigqueue_take(p->p_ksi);
853 * If we got the child via a ptrace 'attach', we need to give it back
856 if (p->p_oppid != 0) {
857 t = proc_realparent(p);
863 pksignal(t, SIGCHLD, p->p_ksi);
865 cv_broadcast(&p->p_pwait);
867 sx_xunlock(&proctree_lock);
872 * Remove other references to this process to ensure we have an
873 * exclusive reference.
875 sx_xlock(&allproc_lock);
876 LIST_REMOVE(p, p_list); /* off zombproc */
877 sx_xunlock(&allproc_lock);
878 LIST_REMOVE(p, p_sibling);
879 reaper_abandon_children(p, true);
880 LIST_REMOVE(p, p_reapsibling);
886 if (p->p_procdesc != NULL)
889 sx_xunlock(&proctree_lock);
892 * As a side effect of this lock, we know that all other writes to
893 * this proc are visible now, so no more locking is needed for p.
896 p->p_xstat = 0; /* XXX: why? */
899 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
903 * Decrement the count of procs running with this uid.
905 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
908 * Destroy resource accounting information associated with the process.
912 racct_sub(p, RACCT_NPROC, 1);
918 * Free credentials, arguments, and sigacts.
922 pargs_drop(p->p_args);
924 sigacts_free(p->p_sigacts);
928 * Do any thread-system specific cleanups.
933 * Give vm and machine-dependent layer a chance to free anything that
934 * cpu_exit couldn't release while still running in process context.
940 KASSERT(FIRST_THREAD_IN_PROC(p),
941 ("proc_reap: no residual thread!"));
942 uma_zfree(proc_zone, p);
943 sx_xlock(&allproc_lock);
945 sx_xunlock(&allproc_lock);
949 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
950 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo)
955 sx_assert(&proctree_lock, SA_XLOCKED);
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)) {
1035 if (siginfo != NULL) {
1036 bzero(siginfo, sizeof(*siginfo));
1037 siginfo->si_errno = 0;
1040 * SUSv4 requires that the si_signo value is always
1041 * SIGCHLD. Obey it despite the rfork(2) interface
1042 * allows to request other signal for child exit
1045 siginfo->si_signo = SIGCHLD;
1048 * This is still a rough estimate. We will fix the
1049 * cases TRAPPED, STOPPED, and CONTINUED later.
1051 if (WCOREDUMP(p->p_xstat)) {
1052 siginfo->si_code = CLD_DUMPED;
1053 siginfo->si_status = WTERMSIG(p->p_xstat);
1054 } else if (WIFSIGNALED(p->p_xstat)) {
1055 siginfo->si_code = CLD_KILLED;
1056 siginfo->si_status = WTERMSIG(p->p_xstat);
1058 siginfo->si_code = CLD_EXITED;
1059 siginfo->si_status = WEXITSTATUS(p->p_xstat);
1062 siginfo->si_pid = p->p_pid;
1063 siginfo->si_uid = p->p_ucred->cr_uid;
1066 * The si_addr field would be useful additional
1067 * detail, but apparently the PC value may be lost
1068 * when we reach this point. bzero() above sets
1069 * siginfo->si_addr to NULL.
1074 * There should be no reason to limit resources usage info to
1075 * exited processes only. A snapshot about any resources used
1076 * by a stopped process may be exactly what is needed.
1078 if (wrusage != NULL) {
1079 rup = &wrusage->wru_self;
1081 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) {
1089 proc_reap(td, p, status, options);
1098 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1099 struct rusage *rusage)
1101 struct __wrusage wru, *wrup;
1107 * Translate the special pid values into the (idtype, pid)
1108 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1109 * kern_wait6() on its own.
1111 if (pid == WAIT_ANY) {
1114 } else if (pid < 0) {
1128 * For backward compatibility we implicitly add flags WEXITED
1129 * and WTRAPPED here.
1131 options |= WEXITED | WTRAPPED;
1132 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1134 *rusage = wru.wru_self;
1139 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1140 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1143 int error, nfound, ret;
1145 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1146 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1147 AUDIT_ARG_VALUE(options);
1151 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1153 id = (id_t)q->p_pgid;
1158 /* If we don't know the option, just return. */
1159 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1160 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1162 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1164 * We will be unable to find any matching processes,
1165 * because there are no known events to look for.
1166 * Prefer to return error instead of blocking
1173 if (q->p_flag & P_STATCHILD) {
1175 q->p_flag &= ~P_STATCHILD;
1179 sx_xlock(&proctree_lock);
1180 LIST_FOREACH(p, &q->p_children, p_sibling) {
1181 ret = proc_to_reap(td, p, idtype, id, status, options,
1193 if ((options & WTRAPPED) != 0 &&
1194 (p->p_flag & P_TRACED) != 0 &&
1195 (p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) != 0 &&
1196 (p->p_suspcount == p->p_numthreads) &&
1197 ((p->p_flag & P_WAITED) == 0)) {
1199 if ((options & WNOWAIT) == 0)
1200 p->p_flag |= P_WAITED;
1201 sx_xunlock(&proctree_lock);
1202 td->td_retval[0] = p->p_pid;
1205 *status = W_STOPCODE(p->p_xstat);
1206 if (siginfo != NULL) {
1207 siginfo->si_status = p->p_xstat;
1208 siginfo->si_code = CLD_TRAPPED;
1210 if ((options & WNOWAIT) == 0) {
1212 sigqueue_take(p->p_ksi);
1219 if ((options & WUNTRACED) != 0 &&
1220 (p->p_flag & P_STOPPED_SIG) != 0 &&
1221 (p->p_suspcount == p->p_numthreads) &&
1222 ((p->p_flag & P_WAITED) == 0)) {
1224 if ((options & WNOWAIT) == 0)
1225 p->p_flag |= P_WAITED;
1226 sx_xunlock(&proctree_lock);
1227 td->td_retval[0] = p->p_pid;
1230 *status = W_STOPCODE(p->p_xstat);
1231 if (siginfo != NULL) {
1232 siginfo->si_status = p->p_xstat;
1233 siginfo->si_code = CLD_STOPPED;
1235 if ((options & WNOWAIT) == 0) {
1237 sigqueue_take(p->p_ksi);
1245 if ((options & WCONTINUED) != 0 &&
1246 (p->p_flag & P_CONTINUED) != 0) {
1247 sx_xunlock(&proctree_lock);
1248 td->td_retval[0] = p->p_pid;
1249 if ((options & WNOWAIT) == 0) {
1250 p->p_flag &= ~P_CONTINUED;
1252 sigqueue_take(p->p_ksi);
1259 if (siginfo != NULL) {
1260 siginfo->si_status = SIGCONT;
1261 siginfo->si_code = CLD_CONTINUED;
1269 * Look in the orphans list too, to allow the parent to
1270 * collect it's child exit status even if child is being
1273 * Debugger detaches from the parent upon successful
1274 * switch-over from parent to child. At this point due to
1275 * re-parenting the parent loses the child to debugger and a
1276 * wait4(2) call would report that it has no children to wait
1277 * for. By maintaining a list of orphans we allow the parent
1278 * to successfully wait until the child becomes a zombie.
1280 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1281 ret = proc_to_reap(td, p, idtype, id, status, options,
1291 sx_xunlock(&proctree_lock);
1294 if (options & WNOHANG) {
1295 sx_xunlock(&proctree_lock);
1296 td->td_retval[0] = 0;
1300 sx_xunlock(&proctree_lock);
1301 if (q->p_flag & P_STATCHILD) {
1302 q->p_flag &= ~P_STATCHILD;
1305 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
1313 * Make process 'parent' the new parent of process 'child'.
1314 * Must be called with an exclusive hold of proctree lock.
1317 proc_reparent(struct proc *child, struct proc *parent)
1320 sx_assert(&proctree_lock, SX_XLOCKED);
1321 PROC_LOCK_ASSERT(child, MA_OWNED);
1322 if (child->p_pptr == parent)
1325 PROC_LOCK(child->p_pptr);
1326 sigqueue_take(child->p_ksi);
1327 PROC_UNLOCK(child->p_pptr);
1328 LIST_REMOVE(child, p_sibling);
1329 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1331 clear_orphan(child);
1332 if (child->p_flag & P_TRACED) {
1333 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1334 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1335 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1338 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1341 child->p_treeflag |= P_TREE_ORPHANED;
1344 child->p_pptr = parent;