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
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
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24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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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>
51 #include <sys/malloc.h>
53 #include <sys/mutex.h>
55 #include <sys/procdesc.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");
100 proc_realparent(struct proc *child)
102 struct proc *p, *parent;
104 sx_assert(&proctree_lock, SX_LOCKED);
105 if ((child->p_treeflag & P_TREE_ORPHANED) == 0)
106 return (child->p_pptr->p_pid == child->p_oppid ?
107 child->p_pptr : child->p_reaper);
108 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
109 /* Cannot use LIST_PREV(), since the list head is not known. */
110 p = __containerof(p->p_orphan.le_prev, struct proc,
112 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
113 ("missing P_ORPHAN %p", p));
115 parent = __containerof(p->p_orphan.le_prev, struct proc,
121 reaper_abandon_children(struct proc *p, bool exiting)
123 struct proc *p1, *p2, *ptmp;
125 sx_assert(&proctree_lock, SX_LOCKED);
126 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
127 if ((p->p_treeflag & P_TREE_REAPER) == 0)
130 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
131 LIST_REMOVE(p2, p_reapsibling);
133 p2->p_reapsubtree = p->p_reapsubtree;
134 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
135 if (exiting && p2->p_pptr == p) {
137 proc_reparent(p2, p1, true);
141 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
142 p->p_treeflag &= ~P_TREE_REAPER;
146 reaper_clear(struct proc *p)
151 sx_assert(&proctree_lock, SX_LOCKED);
152 LIST_REMOVE(p, p_reapsibling);
153 if (p->p_reapsubtree == 1)
156 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) {
157 if (p1->p_reapsubtree == p->p_reapsubtree) {
163 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree);
167 proc_clear_orphan(struct proc *p)
171 sx_assert(&proctree_lock, SA_XLOCKED);
172 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
174 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
175 p1 = LIST_NEXT(p, p_orphan);
177 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
178 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
180 LIST_REMOVE(p, p_orphan);
181 p->p_treeflag &= ~P_TREE_ORPHANED;
185 * exit -- death of process.
188 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
191 exit1(td, uap->rval, 0);
196 * Exit: deallocate address space and other resources, change proc state to
197 * zombie, and unlink proc from allproc and parent's lists. Save exit status
198 * and rusage for wait(). Check for child processes and orphan them.
201 exit1(struct thread *td, int rval, int signo)
203 struct proc *p, *nq, *q, *t;
205 ksiginfo_t *ksi, *ksi1;
208 mtx_assert(&Giant, MA_NOTOWNED);
209 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
213 * XXX in case we're rebooting we just let init die in order to
214 * work around an unsolved stack overflow seen very late during
215 * shutdown on sparc64 when the gmirror worker process exists.
216 * XXX what to do now that sparc64 is gone... remove if?
218 if (p == initproc && rebooting == 0) {
219 printf("init died (signal %d, exit %d)\n", signo, rval);
220 panic("Going nowhere without my init!");
224 * Deref SU mp, since the thread does not return to userspace.
226 td_softdep_cleanup(td);
229 * MUST abort all other threads before proceeding past here.
233 * First check if some other thread or external request got
234 * here before us. If so, act appropriately: exit or suspend.
235 * We must ensure that stop requests are handled before we set
238 thread_suspend_check(0);
239 while (p->p_flag & P_HADTHREADS) {
241 * Kill off the other threads. This requires
242 * some co-operation from other parts of the kernel
243 * so it may not be instantaneous. With this state set
244 * any thread entering the kernel from userspace will
245 * thread_exit() in trap(). Any thread attempting to
246 * sleep will return immediately with EINTR or EWOULDBLOCK
247 * which will hopefully force them to back out to userland
248 * freeing resources as they go. Any thread attempting
249 * to return to userland will thread_exit() from userret().
250 * thread_exit() will unsuspend us when the last of the
251 * other threads exits.
252 * If there is already a thread singler after resumption,
253 * calling thread_single will fail; in that case, we just
254 * re-check all suspension request, the thread should
255 * either be suspended there or exit.
257 if (!thread_single(p, SINGLE_EXIT))
259 * All other activity in this process is now
260 * stopped. Threading support has been turned
265 * Recheck for new stop or suspend requests which
266 * might appear while process lock was dropped in
269 thread_suspend_check(0);
271 KASSERT(p->p_numthreads == 1,
272 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
273 racct_sub(p, RACCT_NTHR, 1);
275 /* Let event handler change exit status */
280 * Ignore any pending request to stop due to a stop signal.
281 * Once P_WEXIT is set, future requests will be ignored as
284 p->p_flag &= ~P_STOPPED_SIG;
285 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
287 /* Note that we are exiting. */
288 p->p_flag |= P_WEXIT;
291 * Wait for any processes that have a hold on our vmspace to
292 * release their reference.
294 while (p->p_lock > 0)
295 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
298 /* Drain the limit callout while we don't have the proc locked */
299 callout_drain(&p->p_limco);
303 * The Sun BSM exit token contains two components: an exit status as
304 * passed to exit(), and a return value to indicate what sort of exit
305 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
306 * what the return value is.
308 AUDIT_ARG_EXIT(rval, 0);
309 AUDIT_SYSCALL_EXIT(0, td);
312 /* Are we a task leader with peers? */
313 if (p->p_peers != NULL && p == p->p_leader) {
314 mtx_lock(&ppeers_lock);
318 kern_psignal(q, SIGKILL);
322 while (p->p_peers != NULL)
323 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
324 mtx_unlock(&ppeers_lock);
328 * Check if any loadable modules need anything done at process exit.
329 * E.g. SYSV IPC stuff.
330 * Event handler could change exit status.
331 * XXX what if one of these generates an error?
333 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
336 * If parent is waiting for us to exit or exec,
337 * P_PPWAIT is set; we will wakeup the parent below.
344 * Stop the real interval timer. If the handler is currently
345 * executing, prevent it from rearming itself and let it finish.
347 if (timevalisset(&p->p_realtimer.it_value) &&
348 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
349 timevalclear(&p->p_realtimer.it_interval);
350 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
351 KASSERT(!timevalisset(&p->p_realtimer.it_value),
352 ("realtime timer is still armed"));
357 umtx_thread_exit(td);
360 * Reset any sigio structures pointing to us as a result of
361 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
363 funsetownlst(&p->p_sigiolst);
366 * Close open files and release open-file table.
372 * If this thread tickled GEOM, we need to wait for the giggling to
373 * stop before we return to userland
375 if (td->td_pflags & TDP_GEOM)
379 * Remove ourself from our leader's peer list and wake our leader.
381 if (p->p_leader->p_peers != NULL) {
382 mtx_lock(&ppeers_lock);
383 if (p->p_leader->p_peers != NULL) {
385 while (q->p_peers != p)
387 q->p_peers = p->p_peers;
390 mtx_unlock(&ppeers_lock);
394 (void)acct_process(td);
400 * Release reference to text vnode
402 if (p->p_textvp != NULL) {
408 * Release our limits structure.
410 lim_free(p->p_limit);
416 * Call machine-dependent code to release any
417 * machine-dependent resources other than the address space.
418 * The address space is released by "vmspace_exitfree(p)" in
423 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
426 * Remove from allproc. It still sits in the hash.
428 sx_xlock(&allproc_lock);
429 LIST_REMOVE(p, p_list);
430 sx_xunlock(&allproc_lock);
432 sx_xlock(&proctree_lock);
434 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
438 * killjobc() might drop and re-acquire proctree_lock to
439 * revoke control tty if exiting process was a session leader.
444 * Reparent all children processes:
445 * - traced ones to the original parent (or init if we are that parent)
448 q = LIST_FIRST(&p->p_children);
449 if (q != NULL) /* only need this if any child is S_ZOMB */
451 for (; q != NULL; q = nq) {
452 nq = LIST_NEXT(q, p_sibling);
453 ksi = ksiginfo_alloc(TRUE);
455 q->p_sigparent = SIGCHLD;
457 if ((q->p_flag & P_TRACED) == 0) {
458 proc_reparent(q, q->p_reaper, true);
459 if (q->p_state == PRS_ZOMBIE) {
461 * Inform reaper about the reparented
462 * zombie, since wait(2) has something
463 * new to report. Guarantee queueing
464 * of the SIGCHLD signal, similar to
465 * the _exit() behaviour, by providing
466 * our ksiginfo. Ksi is freed by the
469 if (q->p_ksi == NULL) {
472 ksiginfo_copy(q->p_ksi, ksi);
473 ksi->ksi_flags |= KSI_INS;
477 PROC_LOCK(q->p_reaper);
478 pksignal(q->p_reaper, SIGCHLD, ksi1);
479 PROC_UNLOCK(q->p_reaper);
480 } else if (q->p_pdeathsig > 0) {
482 * The child asked to received a signal
485 kern_psignal(q, q->p_pdeathsig);
489 * Traced processes are killed since their existence
490 * means someone is screwing up.
492 t = proc_realparent(q);
494 proc_reparent(q, q->p_reaper, true);
497 proc_reparent(q, t, true);
501 * Since q was found on our children list, the
502 * proc_reparent() call moved q to the orphan
503 * list due to present P_TRACED flag. Clear
504 * orphan link for q now while q is locked.
506 proc_clear_orphan(q);
507 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
508 q->p_flag2 &= ~P2_PTRACE_FSTP;
510 FOREACH_THREAD_IN_PROC(q, tdt) {
511 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
514 kern_psignal(q, SIGKILL);
522 * Also get rid of our orphans.
524 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
526 KASSERT(q->p_oppid == p->p_pid,
527 ("orphan %p of %p has unexpected oppid %d", q, p,
529 q->p_oppid = q->p_reaper->p_pid;
532 * If we are the real parent of this process
533 * but it has been reparented to a debugger, then
534 * check if it asked for a signal when we exit.
536 if (q->p_pdeathsig > 0)
537 kern_psignal(q, q->p_pdeathsig);
538 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
540 proc_clear_orphan(q);
545 if (SDT_PROBES_ENABLED()) {
546 int reason = CLD_EXITED;
547 if (WCOREDUMP(signo))
549 else if (WIFSIGNALED(signo))
551 SDT_PROBE1(proc, , , exit, reason);
555 /* Save exit status. */
561 * Tell the DTrace fasttrap provider about the exit if it
562 * has declared an interest.
564 if (dtrace_fasttrap_exit)
565 dtrace_fasttrap_exit(p);
569 * Notify interested parties of our demise.
571 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
574 * If this is a process with a descriptor, we may not need to deliver
575 * a signal to the parent. proctree_lock is held over
576 * procdesc_exit() to serialize concurrent calls to close() and
580 if (p->p_procdesc == NULL || procdesc_exit(p)) {
582 * Notify parent that we're gone. If parent has the
583 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
584 * notify process 1 instead (and hope it will handle this
587 PROC_LOCK(p->p_pptr);
588 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
589 if (p->p_pptr->p_sigacts->ps_flag &
590 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
593 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
596 proc_reparent(p, p->p_reaper, true);
597 p->p_sigparent = SIGCHLD;
598 PROC_LOCK(p->p_pptr);
601 * Notify parent, so in case he was wait(2)ing or
602 * executing waitpid(2) with our pid, he will
607 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
609 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
611 } else if (p->p_sigparent != 0) {
612 if (p->p_sigparent == SIGCHLD) {
614 } else { /* LINUX thread */
619 PROC_LOCK(p->p_pptr);
620 sx_xunlock(&proctree_lock);
622 if (signal_parent == 1) {
624 } else if (signal_parent == 2) {
625 kern_psignal(p->p_pptr, p->p_sigparent);
628 /* Tell the prison that we are gone. */
629 prison_proc_free(p->p_ucred->cr_prison);
632 * The state PRS_ZOMBIE prevents other proesses from sending
633 * signal to the process, to avoid memory leak, we free memory
634 * for signal queue at the time when the state is set.
636 sigqueue_flush(&p->p_sigqueue);
637 sigqueue_flush(&td->td_sigqueue);
640 * We have to wait until after acquiring all locks before
641 * changing p_state. We need to avoid all possible context
642 * switches (including ones from blocking on a mutex) while
643 * marked as a zombie. We also have to set the zombie state
644 * before we release the parent process' proc lock to avoid
645 * a lost wakeup. So, we first call wakeup, then we grab the
646 * sched lock, update the state, and release the parent process'
650 cv_broadcast(&p->p_pwait);
651 sched_exit(p->p_pptr, td);
653 p->p_state = PRS_ZOMBIE;
654 PROC_UNLOCK(p->p_pptr);
657 * Save our children's rusage information in our exit rusage.
660 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
664 * Make sure the scheduler takes this thread out of its tables etc.
665 * This will also release this thread's reference to the ucred.
666 * Other thread parts to release include pcb bits and such.
671 #ifndef _SYS_SYSPROTO_H_
680 sys_abort2(struct thread *td, struct abort2_args *uap)
682 struct proc *p = td->td_proc;
688 * Do it right now so we can log either proper call of abort2(), or
689 * note, that invalid argument was passed. 512 is big enough to
690 * handle 16 arguments' descriptions with additional comments.
692 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
694 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
695 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
697 * Since we can't return from abort2(), send SIGKILL in cases, where
698 * abort2() was called improperly
701 /* Prevent from DoSes from user-space. */
702 if (uap->nargs < 0 || uap->nargs > 16)
704 if (uap->nargs > 0) {
705 if (uap->args == NULL)
707 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
712 * Limit size of 'reason' string to 128. Will fit even when
713 * maximal number of arguments was chosen to be logged.
715 if (uap->why != NULL) {
716 error = sbuf_copyin(sb, uap->why, 128);
720 sbuf_printf(sb, "(null)");
722 if (uap->nargs > 0) {
723 sbuf_printf(sb, "(");
724 for (i = 0;i < uap->nargs; i++)
725 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
726 sbuf_printf(sb, ")");
729 * Final stage: arguments were proper, string has been
730 * successfully copied from userspace, and copying pointers
731 * from user-space succeed.
735 if (sig == SIGKILL) {
737 sbuf_printf(sb, " (Reason text inaccessible)");
741 log(LOG_INFO, "%s", sbuf_data(sb));
749 * The dirty work is handled by kern_wait().
752 owait(struct thread *td, struct owait_args *uap __unused)
756 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
758 td->td_retval[1] = status;
761 #endif /* COMPAT_43 */
764 * The dirty work is handled by kern_wait().
767 sys_wait4(struct thread *td, struct wait4_args *uap)
769 struct rusage ru, *rup;
772 if (uap->rusage != NULL)
776 error = kern_wait(td, uap->pid, &status, uap->options, rup);
777 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
778 error = copyout(&status, uap->status, sizeof(status));
779 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
780 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
785 sys_wait6(struct thread *td, struct wait6_args *uap)
787 struct __wrusage wru, *wrup;
793 idtype = uap->idtype;
796 if (uap->wrusage != NULL)
801 if (uap->info != NULL) {
803 bzero(sip, sizeof(*sip));
808 * We expect all callers of wait6() to know about WEXITED and
811 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
813 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
814 error = copyout(&status, uap->status, sizeof(status));
815 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
816 error = copyout(&wru, uap->wrusage, sizeof(wru));
817 if (uap->info != NULL && error == 0)
818 error = copyout(&si, uap->info, sizeof(si));
823 * Reap the remains of a zombie process and optionally return status and
824 * rusage. Asserts and will release both the proctree_lock and the process
825 * lock as part of its work.
828 proc_reap(struct thread *td, struct proc *p, int *status, int options)
832 sx_assert(&proctree_lock, SA_XLOCKED);
833 PROC_LOCK_ASSERT(p, MA_OWNED);
834 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
836 mtx_spin_wait_unlocked(&p->p_slock);
841 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
842 if (options & WNOWAIT) {
844 * Only poll, returning the status. Caller does not wish to
845 * release the proc struct just yet.
848 sx_xunlock(&proctree_lock);
853 sigqueue_take(p->p_ksi);
857 * If we got the child via a ptrace 'attach', we need to give it back
860 if (p->p_oppid != p->p_pptr->p_pid) {
862 t = proc_realparent(p);
866 "wait: traced child %d moved back to parent %d", p->p_pid,
868 proc_reparent(p, t, false);
870 pksignal(t, SIGCHLD, p->p_ksi);
872 cv_broadcast(&p->p_pwait);
874 sx_xunlock(&proctree_lock);
880 * Remove other references to this process to ensure we have an
881 * exclusive reference.
883 sx_xlock(PIDHASHLOCK(p->p_pid));
884 LIST_REMOVE(p, p_hash);
885 sx_xunlock(PIDHASHLOCK(p->p_pid));
886 LIST_REMOVE(p, p_sibling);
887 reaper_abandon_children(p, true);
890 proc_clear_orphan(p);
893 if (p->p_procdesc != NULL)
895 sx_xunlock(&proctree_lock);
897 proc_id_clear(PROC_ID_PID, p->p_pid);
900 knlist_detach(p->p_klist);
905 * Removal from allproc list and process group list paired with
906 * PROC_LOCK which was executed during that time should guarantee
907 * nothing can reach this process anymore. As such further locking
910 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
913 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
917 * Decrement the count of procs running with this uid.
919 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
922 * Destroy resource accounting information associated with the process.
927 racct_sub(p, RACCT_NPROC, 1);
934 * Free credentials, arguments, and sigacts.
937 pargs_drop(p->p_args);
939 sigacts_free(p->p_sigacts);
943 * Do any thread-system specific cleanups.
948 * Give vm and machine-dependent layer a chance to free anything that
949 * cpu_exit couldn't release while still running in process context.
956 KASSERT(FIRST_THREAD_IN_PROC(p),
957 ("proc_reap: no residual thread!"));
958 uma_zfree(proc_zone, p);
959 atomic_add_int(&nprocs, -1);
963 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
964 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
969 sx_assert(&proctree_lock, SA_XLOCKED);
975 if (p->p_procdesc == NULL ||
976 (p->p_pptr == td->td_proc &&
977 (p->p_flag & P_TRACED) != 0)) {
984 if (p->p_pid != (pid_t)id) {
990 if (p->p_pgid != (pid_t)id) {
996 if (p->p_session->s_sid != (pid_t)id) {
1002 if (p->p_ucred->cr_uid != (uid_t)id) {
1008 if (p->p_ucred->cr_gid != (gid_t)id) {
1014 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1020 * It seems that the thread structures get zeroed out
1021 * at process exit. This makes it impossible to
1022 * support P_SETID, P_CID or P_CPUID.
1029 if (p_canwait(td, p)) {
1034 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1040 * This special case handles a kthread spawned by linux_clone
1041 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1042 * functions need to be able to distinguish between waiting
1043 * on a process and waiting on a thread. It is a thread if
1044 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1045 * signifies we want to wait for threads and not processes.
1047 if ((p->p_sigparent != SIGCHLD) ^
1048 ((options & WLINUXCLONE) != 0)) {
1053 if (siginfo != NULL) {
1054 bzero(siginfo, sizeof(*siginfo));
1055 siginfo->si_errno = 0;
1058 * SUSv4 requires that the si_signo value is always
1059 * SIGCHLD. Obey it despite the rfork(2) interface
1060 * allows to request other signal for child exit
1063 siginfo->si_signo = SIGCHLD;
1066 * This is still a rough estimate. We will fix the
1067 * cases TRAPPED, STOPPED, and CONTINUED later.
1069 if (WCOREDUMP(p->p_xsig)) {
1070 siginfo->si_code = CLD_DUMPED;
1071 siginfo->si_status = WTERMSIG(p->p_xsig);
1072 } else if (WIFSIGNALED(p->p_xsig)) {
1073 siginfo->si_code = CLD_KILLED;
1074 siginfo->si_status = WTERMSIG(p->p_xsig);
1076 siginfo->si_code = CLD_EXITED;
1077 siginfo->si_status = p->p_xexit;
1080 siginfo->si_pid = p->p_pid;
1081 siginfo->si_uid = p->p_ucred->cr_uid;
1084 * The si_addr field would be useful additional
1085 * detail, but apparently the PC value may be lost
1086 * when we reach this point. bzero() above sets
1087 * siginfo->si_addr to NULL.
1092 * There should be no reason to limit resources usage info to
1093 * exited processes only. A snapshot about any resources used
1094 * by a stopped process may be exactly what is needed.
1096 if (wrusage != NULL) {
1097 rup = &wrusage->wru_self;
1100 calcru(p, &rup->ru_utime, &rup->ru_stime);
1103 rup = &wrusage->wru_children;
1104 *rup = p->p_stats->p_cru;
1105 calccru(p, &rup->ru_utime, &rup->ru_stime);
1108 if (p->p_state == PRS_ZOMBIE && !check_only) {
1109 proc_reap(td, p, status, options);
1116 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1117 struct rusage *rusage)
1119 struct __wrusage wru, *wrup;
1125 * Translate the special pid values into the (idtype, pid)
1126 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1127 * kern_wait6() on its own.
1129 if (pid == WAIT_ANY) {
1132 } else if (pid < 0) {
1146 * For backward compatibility we implicitly add flags WEXITED
1147 * and WTRAPPED here.
1149 options |= WEXITED | WTRAPPED;
1150 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1152 *rusage = wru.wru_self;
1157 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1158 int *status, int options, int si_code)
1162 PROC_LOCK_ASSERT(p, MA_OWNED);
1163 sx_assert(&proctree_lock, SA_XLOCKED);
1164 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1165 si_code == CLD_CONTINUED);
1167 cont = si_code == CLD_CONTINUED;
1168 if ((options & WNOWAIT) == 0) {
1170 p->p_flag &= ~P_CONTINUED;
1172 p->p_flag |= P_WAITED;
1173 PROC_LOCK(td->td_proc);
1174 sigqueue_take(p->p_ksi);
1175 PROC_UNLOCK(td->td_proc);
1177 sx_xunlock(&proctree_lock);
1178 if (siginfo != NULL) {
1179 siginfo->si_code = si_code;
1180 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1183 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1185 td->td_retval[0] = p->p_pid;
1189 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1190 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1194 int error, nfound, ret;
1197 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1198 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1199 AUDIT_ARG_VALUE(options);
1203 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1205 id = (id_t)q->p_pgid;
1210 /* If we don't know the option, just return. */
1211 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1212 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1214 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1216 * We will be unable to find any matching processes,
1217 * because there are no known events to look for.
1218 * Prefer to return error instead of blocking
1225 if (q->p_flag & P_STATCHILD) {
1227 q->p_flag &= ~P_STATCHILD;
1230 sx_xlock(&proctree_lock);
1233 LIST_FOREACH(p, &q->p_children, p_sibling) {
1235 ret = proc_to_reap(td, p, idtype, id, status, options,
1236 wrusage, siginfo, 0);
1239 else if (ret != 1) {
1240 td->td_retval[0] = pid;
1245 PROC_LOCK_ASSERT(p, MA_OWNED);
1247 if ((options & WTRAPPED) != 0 &&
1248 (p->p_flag & P_TRACED) != 0) {
1251 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1252 p->p_suspcount == p->p_numthreads &&
1253 (p->p_flag & P_WAITED) == 0);
1257 "wait: returning trapped pid %d status %#x "
1258 "(xstat %d) xthread %d",
1259 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1260 p->p_xthread != NULL ?
1261 p->p_xthread->td_tid : -1);
1262 report_alive_proc(td, p, siginfo, status,
1263 options, CLD_TRAPPED);
1267 if ((options & WUNTRACED) != 0 &&
1268 (p->p_flag & P_STOPPED_SIG) != 0) {
1270 report = (p->p_suspcount == p->p_numthreads &&
1271 ((p->p_flag & P_WAITED) == 0));
1274 report_alive_proc(td, p, siginfo, status,
1275 options, CLD_STOPPED);
1279 if ((options & WCONTINUED) != 0 &&
1280 (p->p_flag & P_CONTINUED) != 0) {
1281 report_alive_proc(td, p, siginfo, status, options,
1289 * Look in the orphans list too, to allow the parent to
1290 * collect it's child exit status even if child is being
1293 * Debugger detaches from the parent upon successful
1294 * switch-over from parent to child. At this point due to
1295 * re-parenting the parent loses the child to debugger and a
1296 * wait4(2) call would report that it has no children to wait
1297 * for. By maintaining a list of orphans we allow the parent
1298 * to successfully wait until the child becomes a zombie.
1301 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1302 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1305 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1306 (int)td->td_retval[0]));
1314 sx_xunlock(&proctree_lock);
1317 if (options & WNOHANG) {
1318 sx_xunlock(&proctree_lock);
1319 td->td_retval[0] = 0;
1323 if (q->p_flag & P_STATCHILD) {
1324 q->p_flag &= ~P_STATCHILD;
1328 sx_xunlock(&proctree_lock);
1329 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1336 proc_add_orphan(struct proc *child, struct proc *parent)
1339 sx_assert(&proctree_lock, SX_XLOCKED);
1340 KASSERT((child->p_flag & P_TRACED) != 0,
1341 ("proc_add_orphan: not traced"));
1343 if (LIST_EMPTY(&parent->p_orphans)) {
1344 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1345 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1347 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1350 child->p_treeflag |= P_TREE_ORPHANED;
1354 * Make process 'parent' the new parent of process 'child'.
1355 * Must be called with an exclusive hold of proctree lock.
1358 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1361 sx_assert(&proctree_lock, SX_XLOCKED);
1362 PROC_LOCK_ASSERT(child, MA_OWNED);
1363 if (child->p_pptr == parent)
1366 PROC_LOCK(child->p_pptr);
1367 sigqueue_take(child->p_ksi);
1368 PROC_UNLOCK(child->p_pptr);
1369 LIST_REMOVE(child, p_sibling);
1370 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1372 proc_clear_orphan(child);
1373 if ((child->p_flag & P_TRACED) != 0) {
1374 proc_add_orphan(child, child->p_pptr);
1377 child->p_pptr = parent;
1379 child->p_oppid = parent->p_pid;