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
15 * 1. Redistributions of source code must retain 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
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24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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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("$FreeBSD$");
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>
52 #include <sys/malloc.h>
54 #include <sys/mutex.h>
56 #include <sys/procdesc.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/sysctl.h>
70 #include <sys/syslog.h>
71 #include <sys/ptrace.h>
72 #include <sys/acct.h> /* for acct_process() function prototype */
73 #include <sys/filedesc.h>
77 #include <sys/sysent.h>
78 #include <sys/timers.h>
81 #include <sys/ktrace.h>
84 #include <security/audit/audit.h>
85 #include <security/mac/mac_framework.h>
88 #include <vm/vm_extern.h>
89 #include <vm/vm_param.h>
91 #include <vm/vm_map.h>
92 #include <vm/vm_page.h>
96 #include <sys/dtrace_bsd.h>
97 dtrace_execexit_func_t dtrace_fasttrap_exit;
100 SDT_PROVIDER_DECLARE(proc);
101 SDT_PROBE_DEFINE1(proc, , , exit, "int");
103 static int kern_kill_on_dbg_exit = 1;
104 SYSCTL_INT(_kern, OID_AUTO, kill_on_debugger_exit, CTLFLAG_RWTUN,
105 &kern_kill_on_dbg_exit, 0,
106 "Kill ptraced processes when debugger exits");
108 static bool kern_wait_dequeue_sigchld = 1;
109 SYSCTL_BOOL(_kern, OID_AUTO, wait_dequeue_sigchld, CTLFLAG_RWTUN,
110 &kern_wait_dequeue_sigchld, 0,
111 "Dequeue SIGCHLD on wait(2) for live process");
114 proc_realparent(struct proc *child)
116 struct proc *p, *parent;
118 sx_assert(&proctree_lock, SX_LOCKED);
119 if ((child->p_treeflag & P_TREE_ORPHANED) == 0)
120 return (child->p_pptr->p_pid == child->p_oppid ?
121 child->p_pptr : child->p_reaper);
122 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
123 /* Cannot use LIST_PREV(), since the list head is not known. */
124 p = __containerof(p->p_orphan.le_prev, struct proc,
126 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
127 ("missing P_ORPHAN %p", p));
129 parent = __containerof(p->p_orphan.le_prev, struct proc,
135 reaper_abandon_children(struct proc *p, bool exiting)
137 struct proc *p1, *p2, *ptmp;
139 sx_assert(&proctree_lock, SX_LOCKED);
140 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
141 if ((p->p_treeflag & P_TREE_REAPER) == 0)
144 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
145 LIST_REMOVE(p2, p_reapsibling);
147 p2->p_reapsubtree = p->p_reapsubtree;
148 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
149 if (exiting && p2->p_pptr == p) {
151 proc_reparent(p2, p1, true);
155 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
156 p->p_treeflag &= ~P_TREE_REAPER;
160 reaper_clear(struct proc *p)
165 sx_assert(&proctree_lock, SX_LOCKED);
166 LIST_REMOVE(p, p_reapsibling);
167 if (p->p_reapsubtree == 1)
170 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) {
171 if (p1->p_reapsubtree == p->p_reapsubtree) {
177 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree);
181 proc_clear_orphan(struct proc *p)
185 sx_assert(&proctree_lock, SA_XLOCKED);
186 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
188 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
189 p1 = LIST_NEXT(p, p_orphan);
191 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
192 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
194 LIST_REMOVE(p, p_orphan);
195 p->p_treeflag &= ~P_TREE_ORPHANED;
199 * exit -- death of process.
202 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
205 exit1(td, uap->rval, 0);
210 * Exit: deallocate address space and other resources, change proc state to
211 * zombie, and unlink proc from allproc and parent's lists. Save exit status
212 * and rusage for wait(). Check for child processes and orphan them.
215 exit1(struct thread *td, int rval, int signo)
217 struct proc *p, *nq, *q, *t;
219 ksiginfo_t *ksi, *ksi1;
222 mtx_assert(&Giant, MA_NOTOWNED);
223 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
227 * XXX in case we're rebooting we just let init die in order to
228 * work around an unsolved stack overflow seen very late during
229 * shutdown on sparc64 when the gmirror worker process exists.
230 * XXX what to do now that sparc64 is gone... remove if?
232 if (p == initproc && rebooting == 0) {
233 printf("init died (signal %d, exit %d)\n", signo, rval);
234 panic("Going nowhere without my init!");
238 * Deref SU mp, since the thread does not return to userspace.
240 td_softdep_cleanup(td);
243 * MUST abort all other threads before proceeding past here.
247 * First check if some other thread or external request got
248 * here before us. If so, act appropriately: exit or suspend.
249 * We must ensure that stop requests are handled before we set
252 thread_suspend_check(0);
253 while (p->p_flag & P_HADTHREADS) {
255 * Kill off the other threads. This requires
256 * some co-operation from other parts of the kernel
257 * so it may not be instantaneous. With this state set
258 * any thread entering the kernel from userspace will
259 * thread_exit() in trap(). Any thread attempting to
260 * sleep will return immediately with EINTR or EWOULDBLOCK
261 * which will hopefully force them to back out to userland
262 * freeing resources as they go. Any thread attempting
263 * to return to userland will thread_exit() from userret().
264 * thread_exit() will unsuspend us when the last of the
265 * other threads exits.
266 * If there is already a thread singler after resumption,
267 * calling thread_single will fail; in that case, we just
268 * re-check all suspension request, the thread should
269 * either be suspended there or exit.
271 if (!thread_single(p, SINGLE_EXIT))
273 * All other activity in this process is now
274 * stopped. Threading support has been turned
279 * Recheck for new stop or suspend requests which
280 * might appear while process lock was dropped in
283 thread_suspend_check(0);
285 KASSERT(p->p_numthreads == 1,
286 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
287 racct_sub(p, RACCT_NTHR, 1);
289 /* Let event handler change exit status */
294 * Ignore any pending request to stop due to a stop signal.
295 * Once P_WEXIT is set, future requests will be ignored as
298 p->p_flag &= ~P_STOPPED_SIG;
299 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
301 /* Note that we are exiting. */
302 p->p_flag |= P_WEXIT;
305 * Wait for any processes that have a hold on our vmspace to
306 * release their reference.
308 while (p->p_lock > 0)
309 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
312 /* Drain the limit callout while we don't have the proc locked */
313 callout_drain(&p->p_limco);
317 * The Sun BSM exit token contains two components: an exit status as
318 * passed to exit(), and a return value to indicate what sort of exit
319 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
320 * what the return value is.
322 AUDIT_ARG_EXIT(rval, 0);
323 AUDIT_SYSCALL_EXIT(0, td);
326 /* Are we a task leader with peers? */
327 if (p->p_peers != NULL && p == p->p_leader) {
328 mtx_lock(&ppeers_lock);
332 kern_psignal(q, SIGKILL);
336 while (p->p_peers != NULL)
337 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
338 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.
360 * Stop the real interval timer. If the handler is currently
361 * executing, prevent it from rearming itself and let it finish.
363 if (timevalisset(&p->p_realtimer.it_value) &&
364 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
365 timevalclear(&p->p_realtimer.it_interval);
366 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
367 KASSERT(!timevalisset(&p->p_realtimer.it_value),
368 ("realtime timer is still armed"));
373 umtx_thread_exit(td);
374 if (p->p_sysent->sv_onexit != NULL)
375 p->p_sysent->sv_onexit(p);
379 * Reset any sigio structures pointing to us as a result of
380 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
382 funsetownlst(&p->p_sigiolst);
385 * Close open files and release open-file table.
392 * If this thread tickled GEOM, we need to wait for the giggling to
393 * stop before we return to userland
395 if (td->td_pflags & TDP_GEOM)
399 * Remove ourself from our leader's peer list and wake our leader.
401 if (p->p_leader->p_peers != NULL) {
402 mtx_lock(&ppeers_lock);
403 if (p->p_leader->p_peers != NULL) {
405 while (q->p_peers != p)
407 q->p_peers = p->p_peers;
410 mtx_unlock(&ppeers_lock);
414 (void)acct_process(td);
420 * Release reference to text vnode
422 if (p->p_textvp != NULL) {
428 * Release our limits structure.
430 lim_free(p->p_limit);
436 * Call machine-dependent code to release any
437 * machine-dependent resources other than the address space.
438 * The address space is released by "vmspace_exitfree(p)" in
443 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
446 * Remove from allproc. It still sits in the hash.
448 sx_xlock(&allproc_lock);
449 LIST_REMOVE(p, p_list);
453 * Used by ddb's 'ps' command to find this process via the
456 p->p_list.le_prev = NULL;
458 sx_xunlock(&allproc_lock);
460 sx_xlock(&proctree_lock);
462 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
466 * killjobc() might drop and re-acquire proctree_lock to
467 * revoke control tty if exiting process was a session leader.
472 * Reparent all children processes:
473 * - traced ones to the original parent (or init if we are that parent)
476 q = LIST_FIRST(&p->p_children);
477 if (q != NULL) /* only need this if any child is S_ZOMB */
479 for (; q != NULL; q = nq) {
480 nq = LIST_NEXT(q, p_sibling);
481 ksi = ksiginfo_alloc(TRUE);
483 q->p_sigparent = SIGCHLD;
485 if ((q->p_flag & P_TRACED) == 0) {
486 proc_reparent(q, q->p_reaper, true);
487 if (q->p_state == PRS_ZOMBIE) {
489 * Inform reaper about the reparented
490 * zombie, since wait(2) has something
491 * new to report. Guarantee queueing
492 * of the SIGCHLD signal, similar to
493 * the _exit() behaviour, by providing
494 * our ksiginfo. Ksi is freed by the
497 if (q->p_ksi == NULL) {
500 ksiginfo_copy(q->p_ksi, ksi);
501 ksi->ksi_flags |= KSI_INS;
505 PROC_LOCK(q->p_reaper);
506 pksignal(q->p_reaper, SIGCHLD, ksi1);
507 PROC_UNLOCK(q->p_reaper);
508 } else if (q->p_pdeathsig > 0) {
510 * The child asked to received a signal
513 kern_psignal(q, q->p_pdeathsig);
517 * Traced processes are killed by default
518 * since their existence means someone is
521 t = proc_realparent(q);
523 proc_reparent(q, q->p_reaper, true);
526 proc_reparent(q, t, true);
530 * Since q was found on our children list, the
531 * proc_reparent() call moved q to the orphan
532 * list due to present P_TRACED flag. Clear
533 * orphan link for q now while q is locked.
535 proc_clear_orphan(q);
536 q->p_flag &= ~P_TRACED;
537 q->p_flag2 &= ~P2_PTRACE_FSTP;
540 FOREACH_THREAD_IN_PROC(q, tdt) {
541 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
545 if (kern_kill_on_dbg_exit) {
546 q->p_flag &= ~P_STOPPED_TRACE;
547 kern_psignal(q, SIGKILL);
548 } else if ((q->p_flag & (P_STOPPED_TRACE |
549 P_STOPPED_SIG)) != 0) {
550 sigqueue_delete_proc(q, SIGTRAP);
560 * Also get rid of our orphans.
562 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
564 KASSERT(q->p_oppid == p->p_pid,
565 ("orphan %p of %p has unexpected oppid %d", q, p,
567 q->p_oppid = q->p_reaper->p_pid;
570 * If we are the real parent of this process
571 * but it has been reparented to a debugger, then
572 * check if it asked for a signal when we exit.
574 if (q->p_pdeathsig > 0)
575 kern_psignal(q, q->p_pdeathsig);
576 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
578 proc_clear_orphan(q);
583 if (SDT_PROBES_ENABLED()) {
584 int reason = CLD_EXITED;
585 if (WCOREDUMP(signo))
587 else if (WIFSIGNALED(signo))
589 SDT_PROBE1(proc, , , exit, reason);
593 /* Save exit status. */
597 if (p->p_sysent->sv_ontdexit != NULL)
598 p->p_sysent->sv_ontdexit(td);
602 * Tell the DTrace fasttrap provider about the exit if it
603 * has declared an interest.
605 if (dtrace_fasttrap_exit)
606 dtrace_fasttrap_exit(p);
610 * Notify interested parties of our demise.
612 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
615 * If this is a process with a descriptor, we may not need to deliver
616 * a signal to the parent. proctree_lock is held over
617 * procdesc_exit() to serialize concurrent calls to close() and
621 if (p->p_procdesc == NULL || procdesc_exit(p)) {
623 * Notify parent that we're gone. If parent has the
624 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
625 * notify process 1 instead (and hope it will handle this
628 PROC_LOCK(p->p_pptr);
629 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
630 if (p->p_pptr->p_sigacts->ps_flag &
631 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
634 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
637 proc_reparent(p, p->p_reaper, true);
638 p->p_sigparent = SIGCHLD;
639 PROC_LOCK(p->p_pptr);
642 * Notify parent, so in case he was wait(2)ing or
643 * executing waitpid(2) with our pid, he will
648 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
650 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
652 } else if (p->p_sigparent != 0) {
653 if (p->p_sigparent == SIGCHLD) {
655 } else { /* LINUX thread */
660 PROC_LOCK(p->p_pptr);
661 sx_xunlock(&proctree_lock);
663 if (signal_parent == 1) {
665 } else if (signal_parent == 2) {
666 kern_psignal(p->p_pptr, p->p_sigparent);
669 /* Tell the prison that we are gone. */
670 prison_proc_free(p->p_ucred->cr_prison);
673 * The state PRS_ZOMBIE prevents other proesses from sending
674 * signal to the process, to avoid memory leak, we free memory
675 * for signal queue at the time when the state is set.
677 sigqueue_flush(&p->p_sigqueue);
678 sigqueue_flush(&td->td_sigqueue);
681 * We have to wait until after acquiring all locks before
682 * changing p_state. We need to avoid all possible context
683 * switches (including ones from blocking on a mutex) while
684 * marked as a zombie. We also have to set the zombie state
685 * before we release the parent process' proc lock to avoid
686 * a lost wakeup. So, we first call wakeup, then we grab the
687 * sched lock, update the state, and release the parent process'
691 cv_broadcast(&p->p_pwait);
692 sched_exit(p->p_pptr, td);
694 p->p_state = PRS_ZOMBIE;
695 PROC_UNLOCK(p->p_pptr);
698 * Save our children's rusage information in our exit rusage.
701 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
705 * Make sure the scheduler takes this thread out of its tables etc.
706 * This will also release this thread's reference to the ucred.
707 * Other thread parts to release include pcb bits and such.
712 #ifndef _SYS_SYSPROTO_H_
721 sys_abort2(struct thread *td, struct abort2_args *uap)
723 struct proc *p = td->td_proc;
729 * Do it right now so we can log either proper call of abort2(), or
730 * note, that invalid argument was passed. 512 is big enough to
731 * handle 16 arguments' descriptions with additional comments.
733 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
735 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
736 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
738 * Since we can't return from abort2(), send SIGKILL in cases, where
739 * abort2() was called improperly
742 /* Prevent from DoSes from user-space. */
743 if (uap->nargs < 0 || uap->nargs > 16)
745 if (uap->nargs > 0) {
746 if (uap->args == NULL)
748 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
753 * Limit size of 'reason' string to 128. Will fit even when
754 * maximal number of arguments was chosen to be logged.
756 if (uap->why != NULL) {
757 error = sbuf_copyin(sb, uap->why, 128);
761 sbuf_printf(sb, "(null)");
763 if (uap->nargs > 0) {
764 sbuf_printf(sb, "(");
765 for (i = 0;i < uap->nargs; i++)
766 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
767 sbuf_printf(sb, ")");
770 * Final stage: arguments were proper, string has been
771 * successfully copied from userspace, and copying pointers
772 * from user-space succeed.
776 if (sig == SIGKILL) {
778 sbuf_printf(sb, " (Reason text inaccessible)");
782 log(LOG_INFO, "%s", sbuf_data(sb));
790 * The dirty work is handled by kern_wait().
793 owait(struct thread *td, struct owait_args *uap __unused)
797 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
799 td->td_retval[1] = status;
802 #endif /* COMPAT_43 */
805 * The dirty work is handled by kern_wait().
808 sys_wait4(struct thread *td, struct wait4_args *uap)
810 struct rusage ru, *rup;
813 if (uap->rusage != NULL)
817 error = kern_wait(td, uap->pid, &status, uap->options, rup);
818 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
819 error = copyout(&status, uap->status, sizeof(status));
820 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
821 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
826 sys_wait6(struct thread *td, struct wait6_args *uap)
828 struct __wrusage wru, *wrup;
834 idtype = uap->idtype;
837 if (uap->wrusage != NULL)
842 if (uap->info != NULL) {
844 bzero(sip, sizeof(*sip));
849 * We expect all callers of wait6() to know about WEXITED and
852 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
854 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
855 error = copyout(&status, uap->status, sizeof(status));
856 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
857 error = copyout(&wru, uap->wrusage, sizeof(wru));
858 if (uap->info != NULL && error == 0)
859 error = copyout(&si, uap->info, sizeof(si));
864 * Reap the remains of a zombie process and optionally return status and
865 * rusage. Asserts and will release both the proctree_lock and the process
866 * lock as part of its work.
869 proc_reap(struct thread *td, struct proc *p, int *status, int options)
873 sx_assert(&proctree_lock, SA_XLOCKED);
874 PROC_LOCK_ASSERT(p, MA_OWNED);
875 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
877 mtx_spin_wait_unlocked(&p->p_slock);
882 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
883 if (options & WNOWAIT) {
885 * Only poll, returning the status. Caller does not wish to
886 * release the proc struct just yet.
889 sx_xunlock(&proctree_lock);
894 sigqueue_take(p->p_ksi);
898 * If we got the child via a ptrace 'attach', we need to give it back
901 if (p->p_oppid != p->p_pptr->p_pid) {
903 t = proc_realparent(p);
907 "wait: traced child %d moved back to parent %d", p->p_pid,
909 proc_reparent(p, t, false);
911 pksignal(t, SIGCHLD, p->p_ksi);
913 cv_broadcast(&p->p_pwait);
915 sx_xunlock(&proctree_lock);
921 * Remove other references to this process to ensure we have an
922 * exclusive reference.
924 sx_xlock(PIDHASHLOCK(p->p_pid));
925 LIST_REMOVE(p, p_hash);
926 sx_xunlock(PIDHASHLOCK(p->p_pid));
927 LIST_REMOVE(p, p_sibling);
928 reaper_abandon_children(p, true);
931 proc_clear_orphan(p);
934 if (p->p_procdesc != NULL)
936 sx_xunlock(&proctree_lock);
938 proc_id_clear(PROC_ID_PID, p->p_pid);
941 knlist_detach(p->p_klist);
946 * Removal from allproc list and process group list paired with
947 * PROC_LOCK which was executed during that time should guarantee
948 * nothing can reach this process anymore. As such further locking
951 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
954 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
958 * Decrement the count of procs running with this uid.
960 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
963 * Destroy resource accounting information associated with the process.
968 racct_sub(p, RACCT_NPROC, 1);
975 * Free credentials, arguments, and sigacts.
978 pargs_drop(p->p_args);
980 sigacts_free(p->p_sigacts);
984 * Do any thread-system specific cleanups.
989 * Give vm and machine-dependent layer a chance to free anything that
990 * cpu_exit couldn't release while still running in process context.
997 KASSERT(FIRST_THREAD_IN_PROC(p),
998 ("proc_reap: no residual thread!"));
999 uma_zfree(proc_zone, p);
1000 atomic_add_int(&nprocs, -1);
1004 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1005 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1010 sx_assert(&proctree_lock, SA_XLOCKED);
1016 if (p->p_procdesc == NULL ||
1017 (p->p_pptr == td->td_proc &&
1018 (p->p_flag & P_TRACED) != 0)) {
1025 if (p->p_pid != (pid_t)id) {
1031 if (p->p_pgid != (pid_t)id) {
1037 if (p->p_session->s_sid != (pid_t)id) {
1043 if (p->p_ucred->cr_uid != (uid_t)id) {
1049 if (p->p_ucred->cr_gid != (gid_t)id) {
1055 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1061 * It seems that the thread structures get zeroed out
1062 * at process exit. This makes it impossible to
1063 * support P_SETID, P_CID or P_CPUID.
1070 if (p_canwait(td, p)) {
1075 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1081 * This special case handles a kthread spawned by linux_clone
1082 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1083 * functions need to be able to distinguish between waiting
1084 * on a process and waiting on a thread. It is a thread if
1085 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1086 * signifies we want to wait for threads and not processes.
1088 if ((p->p_sigparent != SIGCHLD) ^
1089 ((options & WLINUXCLONE) != 0)) {
1094 if (siginfo != NULL) {
1095 bzero(siginfo, sizeof(*siginfo));
1096 siginfo->si_errno = 0;
1099 * SUSv4 requires that the si_signo value is always
1100 * SIGCHLD. Obey it despite the rfork(2) interface
1101 * allows to request other signal for child exit
1104 siginfo->si_signo = SIGCHLD;
1107 * This is still a rough estimate. We will fix the
1108 * cases TRAPPED, STOPPED, and CONTINUED later.
1110 if (WCOREDUMP(p->p_xsig)) {
1111 siginfo->si_code = CLD_DUMPED;
1112 siginfo->si_status = WTERMSIG(p->p_xsig);
1113 } else if (WIFSIGNALED(p->p_xsig)) {
1114 siginfo->si_code = CLD_KILLED;
1115 siginfo->si_status = WTERMSIG(p->p_xsig);
1117 siginfo->si_code = CLD_EXITED;
1118 siginfo->si_status = p->p_xexit;
1121 siginfo->si_pid = p->p_pid;
1122 siginfo->si_uid = p->p_ucred->cr_uid;
1125 * The si_addr field would be useful additional
1126 * detail, but apparently the PC value may be lost
1127 * when we reach this point. bzero() above sets
1128 * siginfo->si_addr to NULL.
1133 * There should be no reason to limit resources usage info to
1134 * exited processes only. A snapshot about any resources used
1135 * by a stopped process may be exactly what is needed.
1137 if (wrusage != NULL) {
1138 rup = &wrusage->wru_self;
1141 calcru(p, &rup->ru_utime, &rup->ru_stime);
1144 rup = &wrusage->wru_children;
1145 *rup = p->p_stats->p_cru;
1146 calccru(p, &rup->ru_utime, &rup->ru_stime);
1149 if (p->p_state == PRS_ZOMBIE && !check_only) {
1150 proc_reap(td, p, status, options);
1157 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1158 struct rusage *rusage)
1160 struct __wrusage wru, *wrup;
1166 * Translate the special pid values into the (idtype, pid)
1167 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1168 * kern_wait6() on its own.
1170 if (pid == WAIT_ANY) {
1173 } else if (pid < 0) {
1187 * For backward compatibility we implicitly add flags WEXITED
1188 * and WTRAPPED here.
1190 options |= WEXITED | WTRAPPED;
1191 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1193 *rusage = wru.wru_self;
1198 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1199 int *status, int options, int si_code)
1203 PROC_LOCK_ASSERT(p, MA_OWNED);
1204 sx_assert(&proctree_lock, SA_XLOCKED);
1205 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1206 si_code == CLD_CONTINUED);
1208 cont = si_code == CLD_CONTINUED;
1209 if ((options & WNOWAIT) == 0) {
1211 p->p_flag &= ~P_CONTINUED;
1213 p->p_flag |= P_WAITED;
1214 if (kern_wait_dequeue_sigchld &&
1215 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1216 PROC_LOCK(td->td_proc);
1217 sigqueue_take(p->p_ksi);
1218 PROC_UNLOCK(td->td_proc);
1221 sx_xunlock(&proctree_lock);
1222 if (siginfo != NULL) {
1223 siginfo->si_code = si_code;
1224 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1227 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1229 td->td_retval[0] = p->p_pid;
1233 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1234 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1238 int error, nfound, ret;
1241 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1242 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1243 AUDIT_ARG_VALUE(options);
1247 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1249 id = (id_t)q->p_pgid;
1254 /* If we don't know the option, just return. */
1255 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1256 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1258 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1260 * We will be unable to find any matching processes,
1261 * because there are no known events to look for.
1262 * Prefer to return error instead of blocking
1269 if (q->p_flag & P_STATCHILD) {
1271 q->p_flag &= ~P_STATCHILD;
1274 sx_xlock(&proctree_lock);
1277 LIST_FOREACH(p, &q->p_children, p_sibling) {
1279 ret = proc_to_reap(td, p, idtype, id, status, options,
1280 wrusage, siginfo, 0);
1283 else if (ret != 1) {
1284 td->td_retval[0] = pid;
1289 PROC_LOCK_ASSERT(p, MA_OWNED);
1291 if ((options & WTRAPPED) != 0 &&
1292 (p->p_flag & P_TRACED) != 0) {
1295 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1296 p->p_suspcount == p->p_numthreads &&
1297 (p->p_flag & P_WAITED) == 0);
1301 "wait: returning trapped pid %d status %#x "
1302 "(xstat %d) xthread %d",
1303 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1304 p->p_xthread != NULL ?
1305 p->p_xthread->td_tid : -1);
1306 report_alive_proc(td, p, siginfo, status,
1307 options, CLD_TRAPPED);
1311 if ((options & WUNTRACED) != 0 &&
1312 (p->p_flag & P_STOPPED_SIG) != 0) {
1314 report = (p->p_suspcount == p->p_numthreads &&
1315 ((p->p_flag & P_WAITED) == 0));
1318 report_alive_proc(td, p, siginfo, status,
1319 options, CLD_STOPPED);
1323 if ((options & WCONTINUED) != 0 &&
1324 (p->p_flag & P_CONTINUED) != 0) {
1325 report_alive_proc(td, p, siginfo, status, options,
1333 * Look in the orphans list too, to allow the parent to
1334 * collect it's child exit status even if child is being
1337 * Debugger detaches from the parent upon successful
1338 * switch-over from parent to child. At this point due to
1339 * re-parenting the parent loses the child to debugger and a
1340 * wait4(2) call would report that it has no children to wait
1341 * for. By maintaining a list of orphans we allow the parent
1342 * to successfully wait until the child becomes a zombie.
1345 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1346 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1349 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1350 (int)td->td_retval[0]));
1358 sx_xunlock(&proctree_lock);
1361 if (options & WNOHANG) {
1362 sx_xunlock(&proctree_lock);
1363 td->td_retval[0] = 0;
1367 if (q->p_flag & P_STATCHILD) {
1368 q->p_flag &= ~P_STATCHILD;
1372 sx_xunlock(&proctree_lock);
1373 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1380 proc_add_orphan(struct proc *child, struct proc *parent)
1383 sx_assert(&proctree_lock, SX_XLOCKED);
1384 KASSERT((child->p_flag & P_TRACED) != 0,
1385 ("proc_add_orphan: not traced"));
1387 if (LIST_EMPTY(&parent->p_orphans)) {
1388 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1389 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1391 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1394 child->p_treeflag |= P_TREE_ORPHANED;
1398 * Make process 'parent' the new parent of process 'child'.
1399 * Must be called with an exclusive hold of proctree lock.
1402 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1405 sx_assert(&proctree_lock, SX_XLOCKED);
1406 PROC_LOCK_ASSERT(child, MA_OWNED);
1407 if (child->p_pptr == parent)
1410 PROC_LOCK(child->p_pptr);
1411 sigqueue_take(child->p_ksi);
1412 PROC_UNLOCK(child->p_pptr);
1413 LIST_REMOVE(child, p_sibling);
1414 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1416 proc_clear_orphan(child);
1417 if ((child->p_flag & P_TRACED) != 0) {
1418 proc_add_orphan(child, child->p_pptr);
1421 child->p_pptr = parent;
1423 child->p_oppid = parent->p_pid;