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.
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
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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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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
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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_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);
102 EVENTHANDLER_LIST_DECLARE(process_exit);
105 proc_realparent(struct proc *child)
107 struct proc *p, *parent;
109 sx_assert(&proctree_lock, SX_LOCKED);
110 if ((child->p_treeflag & P_TREE_ORPHANED) == 0)
111 return (child->p_pptr->p_pid == child->p_oppid ?
112 child->p_pptr : initproc);
113 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
114 /* Cannot use LIST_PREV(), since the list head is not known. */
115 p = __containerof(p->p_orphan.le_prev, struct proc,
117 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
118 ("missing P_ORPHAN %p", p));
120 parent = __containerof(p->p_orphan.le_prev, struct proc,
126 reaper_abandon_children(struct proc *p, bool exiting)
128 struct proc *p1, *p2, *ptmp;
130 sx_assert(&proctree_lock, SX_LOCKED);
131 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
132 if ((p->p_treeflag & P_TREE_REAPER) == 0)
135 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
136 LIST_REMOVE(p2, p_reapsibling);
138 p2->p_reapsubtree = p->p_reapsubtree;
139 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
140 if (exiting && p2->p_pptr == p) {
142 proc_reparent(p2, p1, true);
146 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
147 p->p_treeflag &= ~P_TREE_REAPER;
151 clear_orphan(struct proc *p)
155 sx_assert(&proctree_lock, SA_XLOCKED);
156 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
158 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
159 p1 = LIST_NEXT(p, p_orphan);
161 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
162 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
164 LIST_REMOVE(p, p_orphan);
165 p->p_treeflag &= ~P_TREE_ORPHANED;
169 * exit -- death of process.
172 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
175 exit1(td, uap->rval, 0);
180 * Exit: deallocate address space and other resources, change proc state to
181 * zombie, and unlink proc from allproc and parent's lists. Save exit status
182 * and rusage for wait(). Check for child processes and orphan them.
185 exit1(struct thread *td, int rval, int signo)
187 struct proc *p, *nq, *q, *t;
189 ksiginfo_t *ksi, *ksi1;
192 mtx_assert(&Giant, MA_NOTOWNED);
193 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
197 * XXX in case we're rebooting we just let init die in order to
198 * work around an unsolved stack overflow seen very late during
199 * shutdown on sparc64 when the gmirror worker process exists.
201 if (p == initproc && rebooting == 0) {
202 printf("init died (signal %d, exit %d)\n", signo, rval);
203 panic("Going nowhere without my init!");
207 * Deref SU mp, since the thread does not return to userspace.
209 td_softdep_cleanup(td);
212 * MUST abort all other threads before proceeding past here.
216 * First check if some other thread or external request got
217 * here before us. If so, act appropriately: exit or suspend.
218 * We must ensure that stop requests are handled before we set
221 thread_suspend_check(0);
222 while (p->p_flag & P_HADTHREADS) {
224 * Kill off the other threads. This requires
225 * some co-operation from other parts of the kernel
226 * so it may not be instantaneous. With this state set
227 * any thread entering the kernel from userspace will
228 * thread_exit() in trap(). Any thread attempting to
229 * sleep will return immediately with EINTR or EWOULDBLOCK
230 * which will hopefully force them to back out to userland
231 * freeing resources as they go. Any thread attempting
232 * to return to userland will thread_exit() from userret().
233 * thread_exit() will unsuspend us when the last of the
234 * other threads exits.
235 * If there is already a thread singler after resumption,
236 * calling thread_single will fail; in that case, we just
237 * re-check all suspension request, the thread should
238 * either be suspended there or exit.
240 if (!thread_single(p, SINGLE_EXIT))
242 * All other activity in this process is now
243 * stopped. Threading support has been turned
248 * Recheck for new stop or suspend requests which
249 * might appear while process lock was dropped in
252 thread_suspend_check(0);
254 KASSERT(p->p_numthreads == 1,
255 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
256 racct_sub(p, RACCT_NTHR, 1);
258 /* Let event handler change exit status */
263 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
264 * on our vmspace, so we should block below until they have
265 * released their reference to us. Note that if they have
266 * requested S_EXIT stops we will block here until they ack
269 _STOPEVENT(p, S_EXIT, 0);
272 * Ignore any pending request to stop due to a stop signal.
273 * Once P_WEXIT is set, future requests will be ignored as
276 p->p_flag &= ~P_STOPPED_SIG;
277 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
280 * Note that we are exiting and do another wakeup of anyone in
281 * PIOCWAIT in case they aren't listening for S_EXIT stops or
282 * decided to wait again after we told them we are exiting.
284 p->p_flag |= P_WEXIT;
288 * Wait for any processes that have a hold on our vmspace to
289 * release their reference.
291 while (p->p_lock > 0)
292 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
295 /* Drain the limit callout while we don't have the proc locked */
296 callout_drain(&p->p_limco);
300 * The Sun BSM exit token contains two components: an exit status as
301 * passed to exit(), and a return value to indicate what sort of exit
302 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
303 * what the return value is.
305 AUDIT_ARG_EXIT(rval, 0);
306 AUDIT_SYSCALL_EXIT(0, td);
309 /* Are we a task leader with peers? */
310 if (p->p_peers != NULL && p == p->p_leader) {
311 mtx_lock(&ppeers_lock);
315 kern_psignal(q, SIGKILL);
319 while (p->p_peers != NULL)
320 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
321 mtx_unlock(&ppeers_lock);
325 * Check if any loadable modules need anything done at process exit.
326 * E.g. SYSV IPC stuff.
327 * Event handler could change exit status.
328 * XXX what if one of these generates an error?
330 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
333 * If parent is waiting for us to exit or exec,
334 * P_PPWAIT is set; we will wakeup the parent below.
338 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
342 * Stop the real interval timer. If the handler is currently
343 * executing, prevent it from rearming itself and let it finish.
345 if (timevalisset(&p->p_realtimer.it_value) &&
346 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
347 timevalclear(&p->p_realtimer.it_interval);
348 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
349 KASSERT(!timevalisset(&p->p_realtimer.it_value),
350 ("realtime timer is still armed"));
355 umtx_thread_exit(td);
358 * Reset any sigio structures pointing to us as a result of
359 * F_SETOWN with our pid.
361 funsetownlst(&p->p_sigiolst);
364 * If this process has an nlminfo data area (for lockd), release it
366 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
367 (*nlminfo_release_p)(p);
370 * Close open files and release open-file table.
376 * If this thread tickled GEOM, we need to wait for the giggling to
377 * stop before we return to userland
379 if (td->td_pflags & TDP_GEOM)
383 * Remove ourself from our leader's peer list and wake our leader.
385 if (p->p_leader->p_peers != NULL) {
386 mtx_lock(&ppeers_lock);
387 if (p->p_leader->p_peers != NULL) {
389 while (q->p_peers != p)
391 q->p_peers = p->p_peers;
394 mtx_unlock(&ppeers_lock);
399 (void)acct_process(td);
405 * Release reference to text vnode
407 if (p->p_textvp != NULL) {
413 * Release our limits structure.
415 lim_free(p->p_limit);
421 * Call machine-dependent code to release any
422 * machine-dependent resources other than the address space.
423 * The address space is released by "vmspace_exitfree(p)" in
428 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
430 sx_xlock(&proctree_lock);
432 * Remove proc from allproc queue and pidhash chain.
433 * Place onto zombproc. Unlink from parent's child list.
435 sx_xlock(&allproc_lock);
436 LIST_REMOVE(p, p_list);
437 LIST_INSERT_HEAD(&zombproc, p, p_list);
438 LIST_REMOVE(p, p_hash);
439 sx_xunlock(&allproc_lock);
442 * Reparent all children processes:
443 * - traced ones to the original parent (or init if we are that parent)
446 q = LIST_FIRST(&p->p_children);
447 if (q != NULL) /* only need this if any child is S_ZOMB */
449 for (; q != NULL; q = nq) {
450 nq = LIST_NEXT(q, p_sibling);
451 ksi = ksiginfo_alloc(TRUE);
453 q->p_sigparent = SIGCHLD;
455 if (!(q->p_flag & P_TRACED)) {
456 proc_reparent(q, q->p_reaper, true);
457 if (q->p_state == PRS_ZOMBIE) {
459 * Inform reaper about the reparented
460 * zombie, since wait(2) has something
461 * new to report. Guarantee queueing
462 * of the SIGCHLD signal, similar to
463 * the _exit() behaviour, by providing
464 * our ksiginfo. Ksi is freed by the
467 if (q->p_ksi == NULL) {
470 ksiginfo_copy(q->p_ksi, ksi);
471 ksi->ksi_flags |= KSI_INS;
475 PROC_LOCK(q->p_reaper);
476 pksignal(q->p_reaper, SIGCHLD, ksi1);
477 PROC_UNLOCK(q->p_reaper);
478 } else if (q->p_pdeathsig > 0) {
480 * The child asked to received a signal
483 kern_psignal(q, q->p_pdeathsig);
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, true);
495 proc_reparent(q, t, true);
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) {
525 * If we are the real parent of this process
526 * but it has been reparented to a debugger, then
527 * check if it asked for a signal when we exit.
529 if (q->p_pdeathsig > 0)
530 kern_psignal(q, q->p_pdeathsig);
531 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
537 /* Save exit status. */
543 * Tell the DTrace fasttrap provider about the exit if it
544 * has declared an interest.
546 if (dtrace_fasttrap_exit)
547 dtrace_fasttrap_exit(p);
551 * Notify interested parties of our demise.
553 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
556 int reason = CLD_EXITED;
557 if (WCOREDUMP(signo))
559 else if (WIFSIGNALED(signo))
561 SDT_PROBE1(proc, , , exit, reason);
565 * If this is a process with a descriptor, we may not need to deliver
566 * a signal to the parent. proctree_lock is held over
567 * procdesc_exit() to serialize concurrent calls to close() and
571 if (p->p_procdesc == NULL || procdesc_exit(p)) {
573 * Notify parent that we're gone. If parent has the
574 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
575 * notify process 1 instead (and hope it will handle this
578 PROC_LOCK(p->p_pptr);
579 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
580 if (p->p_pptr->p_sigacts->ps_flag &
581 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
584 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
587 proc_reparent(p, p->p_reaper, true);
588 p->p_sigparent = SIGCHLD;
589 PROC_LOCK(p->p_pptr);
592 * Notify parent, so in case he was wait(2)ing or
593 * executing waitpid(2) with our pid, he will
598 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
600 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
602 } else if (p->p_sigparent != 0) {
603 if (p->p_sigparent == SIGCHLD) {
605 } else { /* LINUX thread */
610 PROC_LOCK(p->p_pptr);
611 sx_xunlock(&proctree_lock);
613 if (signal_parent == 1) {
615 } else if (signal_parent == 2) {
616 kern_psignal(p->p_pptr, p->p_sigparent);
619 /* Tell the prison that we are gone. */
620 prison_proc_free(p->p_ucred->cr_prison);
623 * The state PRS_ZOMBIE prevents other proesses from sending
624 * signal to the process, to avoid memory leak, we free memory
625 * for signal queue at the time when the state is set.
627 sigqueue_flush(&p->p_sigqueue);
628 sigqueue_flush(&td->td_sigqueue);
631 * We have to wait until after acquiring all locks before
632 * changing p_state. We need to avoid all possible context
633 * switches (including ones from blocking on a mutex) while
634 * marked as a zombie. We also have to set the zombie state
635 * before we release the parent process' proc lock to avoid
636 * a lost wakeup. So, we first call wakeup, then we grab the
637 * sched lock, update the state, and release the parent process'
641 cv_broadcast(&p->p_pwait);
642 sched_exit(p->p_pptr, td);
644 p->p_state = PRS_ZOMBIE;
645 PROC_UNLOCK(p->p_pptr);
648 * Save our children's rusage information in our exit rusage.
651 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
655 * Make sure the scheduler takes this thread out of its tables etc.
656 * This will also release this thread's reference to the ucred.
657 * Other thread parts to release include pcb bits and such.
663 #ifndef _SYS_SYSPROTO_H_
672 sys_abort2(struct thread *td, struct abort2_args *uap)
674 struct proc *p = td->td_proc;
680 * Do it right now so we can log either proper call of abort2(), or
681 * note, that invalid argument was passed. 512 is big enough to
682 * handle 16 arguments' descriptions with additional comments.
684 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
686 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
687 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
689 * Since we can't return from abort2(), send SIGKILL in cases, where
690 * abort2() was called improperly
693 /* Prevent from DoSes from user-space. */
694 if (uap->nargs < 0 || uap->nargs > 16)
696 if (uap->nargs > 0) {
697 if (uap->args == NULL)
699 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
704 * Limit size of 'reason' string to 128. Will fit even when
705 * maximal number of arguments was chosen to be logged.
707 if (uap->why != NULL) {
708 error = sbuf_copyin(sb, uap->why, 128);
712 sbuf_printf(sb, "(null)");
714 if (uap->nargs > 0) {
715 sbuf_printf(sb, "(");
716 for (i = 0;i < uap->nargs; i++)
717 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
718 sbuf_printf(sb, ")");
721 * Final stage: arguments were proper, string has been
722 * successfully copied from userspace, and copying pointers
723 * from user-space succeed.
727 if (sig == SIGKILL) {
729 sbuf_printf(sb, " (Reason text inaccessible)");
733 log(LOG_INFO, "%s", sbuf_data(sb));
742 * The dirty work is handled by kern_wait().
745 owait(struct thread *td, struct owait_args *uap __unused)
749 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
751 td->td_retval[1] = status;
754 #endif /* COMPAT_43 */
757 * The dirty work is handled by kern_wait().
760 sys_wait4(struct thread *td, struct wait4_args *uap)
762 struct rusage ru, *rup;
765 if (uap->rusage != NULL)
769 error = kern_wait(td, uap->pid, &status, uap->options, rup);
770 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
771 error = copyout(&status, uap->status, sizeof(status));
772 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
773 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
778 sys_wait6(struct thread *td, struct wait6_args *uap)
780 struct __wrusage wru, *wrup;
786 idtype = uap->idtype;
789 if (uap->wrusage != NULL)
794 if (uap->info != NULL) {
796 bzero(sip, sizeof(*sip));
801 * We expect all callers of wait6() to know about WEXITED and
804 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
806 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
807 error = copyout(&status, uap->status, sizeof(status));
808 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
809 error = copyout(&wru, uap->wrusage, sizeof(wru));
810 if (uap->info != NULL && error == 0)
811 error = copyout(&si, uap->info, sizeof(si));
816 * Reap the remains of a zombie process and optionally return status and
817 * rusage. Asserts and will release both the proctree_lock and the process
818 * lock as part of its work.
821 proc_reap(struct thread *td, struct proc *p, int *status, int options)
825 sx_assert(&proctree_lock, SA_XLOCKED);
826 PROC_LOCK_ASSERT(p, MA_OWNED);
827 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
829 mtx_spin_wait_unlocked(&p->p_slock);
834 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
835 if (options & WNOWAIT) {
837 * Only poll, returning the status. Caller does not wish to
838 * release the proc struct just yet.
841 sx_xunlock(&proctree_lock);
846 sigqueue_take(p->p_ksi);
850 * If we got the child via a ptrace 'attach', we need to give it back
853 if (p->p_oppid != p->p_pptr->p_pid) {
855 t = proc_realparent(p);
859 "wait: traced child %d moved back to parent %d", p->p_pid,
861 proc_reparent(p, t, false);
863 pksignal(t, SIGCHLD, p->p_ksi);
865 cv_broadcast(&p->p_pwait);
867 sx_xunlock(&proctree_lock);
873 * Remove other references to this process to ensure we have an
874 * exclusive reference.
876 sx_xlock(&allproc_lock);
877 LIST_REMOVE(p, p_list); /* off zombproc */
878 sx_xunlock(&allproc_lock);
879 LIST_REMOVE(p, p_sibling);
880 reaper_abandon_children(p, true);
881 LIST_REMOVE(p, p_reapsibling);
886 if (p->p_procdesc != NULL)
888 sx_xunlock(&proctree_lock);
891 knlist_detach(p->p_klist);
896 * Removal from allproc list and process group list paired with
897 * PROC_LOCK which was executed during that time should guarantee
898 * nothing can reach this process anymore. As such further locking
901 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
904 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
908 * Decrement the count of procs running with this uid.
910 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
913 * Destroy resource accounting information associated with the process.
918 racct_sub(p, RACCT_NPROC, 1);
925 * Free credentials, arguments, and sigacts.
928 proc_set_cred(p, NULL);
929 pargs_drop(p->p_args);
931 sigacts_free(p->p_sigacts);
935 * Do any thread-system specific cleanups.
940 * Give vm and machine-dependent layer a chance to free anything that
941 * cpu_exit couldn't release while still running in process context.
948 KASSERT(FIRST_THREAD_IN_PROC(p),
949 ("proc_reap: no residual thread!"));
950 uma_zfree(proc_zone, p);
951 atomic_add_int(&nprocs, -1);
955 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
956 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
961 sx_assert(&proctree_lock, SA_XLOCKED);
967 if (p->p_procdesc != NULL) {
973 if (p->p_pid != (pid_t)id) {
979 if (p->p_pgid != (pid_t)id) {
985 if (p->p_session->s_sid != (pid_t)id) {
991 if (p->p_ucred->cr_uid != (uid_t)id) {
997 if (p->p_ucred->cr_gid != (gid_t)id) {
1003 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1009 * It seems that the thread structures get zeroed out
1010 * at process exit. This makes it impossible to
1011 * support P_SETID, P_CID or P_CPUID.
1018 if (p_canwait(td, p)) {
1023 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1029 * This special case handles a kthread spawned by linux_clone
1030 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1031 * functions need to be able to distinguish between waiting
1032 * on a process and waiting on a thread. It is a thread if
1033 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1034 * signifies we want to wait for threads and not processes.
1036 if ((p->p_sigparent != SIGCHLD) ^
1037 ((options & WLINUXCLONE) != 0)) {
1042 if (siginfo != NULL) {
1043 bzero(siginfo, sizeof(*siginfo));
1044 siginfo->si_errno = 0;
1047 * SUSv4 requires that the si_signo value is always
1048 * SIGCHLD. Obey it despite the rfork(2) interface
1049 * allows to request other signal for child exit
1052 siginfo->si_signo = SIGCHLD;
1055 * This is still a rough estimate. We will fix the
1056 * cases TRAPPED, STOPPED, and CONTINUED later.
1058 if (WCOREDUMP(p->p_xsig)) {
1059 siginfo->si_code = CLD_DUMPED;
1060 siginfo->si_status = WTERMSIG(p->p_xsig);
1061 } else if (WIFSIGNALED(p->p_xsig)) {
1062 siginfo->si_code = CLD_KILLED;
1063 siginfo->si_status = WTERMSIG(p->p_xsig);
1065 siginfo->si_code = CLD_EXITED;
1066 siginfo->si_status = p->p_xexit;
1069 siginfo->si_pid = p->p_pid;
1070 siginfo->si_uid = p->p_ucred->cr_uid;
1073 * The si_addr field would be useful additional
1074 * detail, but apparently the PC value may be lost
1075 * when we reach this point. bzero() above sets
1076 * siginfo->si_addr to NULL.
1081 * There should be no reason to limit resources usage info to
1082 * exited processes only. A snapshot about any resources used
1083 * by a stopped process may be exactly what is needed.
1085 if (wrusage != NULL) {
1086 rup = &wrusage->wru_self;
1089 calcru(p, &rup->ru_utime, &rup->ru_stime);
1092 rup = &wrusage->wru_children;
1093 *rup = p->p_stats->p_cru;
1094 calccru(p, &rup->ru_utime, &rup->ru_stime);
1097 if (p->p_state == PRS_ZOMBIE && !check_only) {
1098 proc_reap(td, p, status, options);
1105 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1106 struct rusage *rusage)
1108 struct __wrusage wru, *wrup;
1114 * Translate the special pid values into the (idtype, pid)
1115 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1116 * kern_wait6() on its own.
1118 if (pid == WAIT_ANY) {
1121 } else if (pid < 0) {
1135 * For backward compatibility we implicitly add flags WEXITED
1136 * and WTRAPPED here.
1138 options |= WEXITED | WTRAPPED;
1139 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1141 *rusage = wru.wru_self;
1146 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1147 int *status, int options, int si_code)
1151 PROC_LOCK_ASSERT(p, MA_OWNED);
1152 sx_assert(&proctree_lock, SA_XLOCKED);
1153 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1154 si_code == CLD_CONTINUED);
1156 cont = si_code == CLD_CONTINUED;
1157 if ((options & WNOWAIT) == 0) {
1159 p->p_flag &= ~P_CONTINUED;
1161 p->p_flag |= P_WAITED;
1162 PROC_LOCK(td->td_proc);
1163 sigqueue_take(p->p_ksi);
1164 PROC_UNLOCK(td->td_proc);
1166 sx_xunlock(&proctree_lock);
1167 if (siginfo != NULL) {
1168 siginfo->si_code = si_code;
1169 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1172 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1174 td->td_retval[0] = p->p_pid;
1178 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1179 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1183 int error, nfound, ret;
1186 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1187 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1188 AUDIT_ARG_VALUE(options);
1192 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1194 id = (id_t)q->p_pgid;
1199 /* If we don't know the option, just return. */
1200 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1201 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1203 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1205 * We will be unable to find any matching processes,
1206 * because there are no known events to look for.
1207 * Prefer to return error instead of blocking
1214 if (q->p_flag & P_STATCHILD) {
1216 q->p_flag &= ~P_STATCHILD;
1219 sx_xlock(&proctree_lock);
1222 LIST_FOREACH(p, &q->p_children, p_sibling) {
1224 ret = proc_to_reap(td, p, idtype, id, status, options,
1225 wrusage, siginfo, 0);
1228 else if (ret != 1) {
1229 td->td_retval[0] = pid;
1234 PROC_LOCK_ASSERT(p, MA_OWNED);
1236 if ((options & WTRAPPED) != 0 &&
1237 (p->p_flag & P_TRACED) != 0) {
1240 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1241 p->p_suspcount == p->p_numthreads &&
1242 (p->p_flag & P_WAITED) == 0);
1246 "wait: returning trapped pid %d status %#x "
1247 "(xstat %d) xthread %d",
1248 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1249 p->p_xthread != NULL ?
1250 p->p_xthread->td_tid : -1);
1251 report_alive_proc(td, p, siginfo, status,
1252 options, CLD_TRAPPED);
1256 if ((options & WUNTRACED) != 0 &&
1257 (p->p_flag & P_STOPPED_SIG) != 0) {
1259 report = (p->p_suspcount == p->p_numthreads &&
1260 ((p->p_flag & P_WAITED) == 0));
1263 report_alive_proc(td, p, siginfo, status,
1264 options, CLD_STOPPED);
1268 if ((options & WCONTINUED) != 0 &&
1269 (p->p_flag & P_CONTINUED) != 0) {
1270 report_alive_proc(td, p, siginfo, status, options,
1278 * Look in the orphans list too, to allow the parent to
1279 * collect it's child exit status even if child is being
1282 * Debugger detaches from the parent upon successful
1283 * switch-over from parent to child. At this point due to
1284 * re-parenting the parent loses the child to debugger and a
1285 * wait4(2) call would report that it has no children to wait
1286 * for. By maintaining a list of orphans we allow the parent
1287 * to successfully wait until the child becomes a zombie.
1290 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1291 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1294 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1295 (int)td->td_retval[0]));
1303 sx_xunlock(&proctree_lock);
1306 if (options & WNOHANG) {
1307 sx_xunlock(&proctree_lock);
1308 td->td_retval[0] = 0;
1312 if (q->p_flag & P_STATCHILD) {
1313 q->p_flag &= ~P_STATCHILD;
1317 sx_xunlock(&proctree_lock);
1318 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1325 * Make process 'parent' the new parent of process 'child'.
1326 * Must be called with an exclusive hold of proctree lock.
1329 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1332 sx_assert(&proctree_lock, SX_XLOCKED);
1333 PROC_LOCK_ASSERT(child, MA_OWNED);
1334 if (child->p_pptr == parent)
1337 PROC_LOCK(child->p_pptr);
1338 sigqueue_take(child->p_ksi);
1339 PROC_UNLOCK(child->p_pptr);
1340 LIST_REMOVE(child, p_sibling);
1341 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1343 clear_orphan(child);
1344 if (child->p_flag & P_TRACED) {
1345 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1346 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1347 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1350 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1353 child->p_treeflag |= P_TREE_ORPHANED;
1356 child->p_pptr = parent;
1358 child->p_oppid = parent->p_pid;