2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
42 #include "opt_compat.h"
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/capsicum.h>
49 #include <sys/eventhandler.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
53 #include <sys/mutex.h>
55 #include <sys/procdesc.h>
56 #include <sys/pioctl.h>
60 #include <sys/vmmeter.h>
61 #include <sys/vnode.h>
62 #include <sys/racct.h>
63 #include <sys/resourcevar.h>
65 #include <sys/signalvar.h>
66 #include <sys/sched.h>
68 #include <sys/syscallsubr.h>
69 #include <sys/syslog.h>
70 #include <sys/ptrace.h>
71 #include <sys/acct.h> /* for acct_process() function prototype */
72 #include <sys/filedesc.h>
78 #include <sys/ktrace.h>
81 #include <security/audit/audit.h>
82 #include <security/mac/mac_framework.h>
85 #include <vm/vm_extern.h>
86 #include <vm/vm_param.h>
88 #include <vm/vm_map.h>
89 #include <vm/vm_page.h>
93 #include <sys/dtrace_bsd.h>
94 dtrace_execexit_func_t dtrace_fasttrap_exit;
97 SDT_PROVIDER_DECLARE(proc);
98 SDT_PROBE_DEFINE1(proc, , , exit, "int");
100 /* Hook for NFS teardown procedure. */
101 void (*nlminfo_release_p)(struct proc *p);
103 EVENTHANDLER_LIST_DECLARE(process_exit);
106 proc_realparent(struct proc *child)
108 struct proc *p, *parent;
110 sx_assert(&proctree_lock, SX_LOCKED);
111 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) {
112 if (child->p_oppid == 0 ||
113 child->p_pptr->p_pid == child->p_oppid)
114 parent = child->p_pptr;
119 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
120 /* Cannot use LIST_PREV(), since the list head is not known. */
121 p = __containerof(p->p_orphan.le_prev, struct proc,
123 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
124 ("missing P_ORPHAN %p", p));
126 parent = __containerof(p->p_orphan.le_prev, struct proc,
132 reaper_abandon_children(struct proc *p, bool exiting)
134 struct proc *p1, *p2, *ptmp;
136 sx_assert(&proctree_lock, SX_LOCKED);
137 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
138 if ((p->p_treeflag & P_TREE_REAPER) == 0)
141 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
142 LIST_REMOVE(p2, p_reapsibling);
144 p2->p_reapsubtree = p->p_reapsubtree;
145 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
146 if (exiting && p2->p_pptr == p) {
148 proc_reparent(p2, p1);
152 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
153 p->p_treeflag &= ~P_TREE_REAPER;
157 clear_orphan(struct proc *p)
161 sx_assert(&proctree_lock, SA_XLOCKED);
162 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
164 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
165 p1 = LIST_NEXT(p, p_orphan);
167 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
168 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
170 LIST_REMOVE(p, p_orphan);
171 p->p_treeflag &= ~P_TREE_ORPHANED;
175 * exit -- death of process.
178 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
181 exit1(td, uap->rval, 0);
186 * Exit: deallocate address space and other resources, change proc state to
187 * zombie, and unlink proc from allproc and parent's lists. Save exit status
188 * and rusage for wait(). Check for child processes and orphan them.
191 exit1(struct thread *td, int rval, int signo)
193 struct proc *p, *nq, *q, *t;
195 ksiginfo_t *ksi, *ksi1;
198 mtx_assert(&Giant, MA_NOTOWNED);
199 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
203 * XXX in case we're rebooting we just let init die in order to
204 * work around an unsolved stack overflow seen very late during
205 * shutdown on sparc64 when the gmirror worker process exists.
207 if (p == initproc && rebooting == 0) {
208 printf("init died (signal %d, exit %d)\n", signo, rval);
209 panic("Going nowhere without my init!");
213 * Deref SU mp, since the thread does not return to userspace.
215 td_softdep_cleanup(td);
218 * MUST abort all other threads before proceeding past here.
222 * First check if some other thread or external request got
223 * here before us. If so, act appropriately: exit or suspend.
224 * We must ensure that stop requests are handled before we set
227 thread_suspend_check(0);
228 while (p->p_flag & P_HADTHREADS) {
230 * Kill off the other threads. This requires
231 * some co-operation from other parts of the kernel
232 * so it may not be instantaneous. With this state set
233 * any thread entering the kernel from userspace will
234 * thread_exit() in trap(). Any thread attempting to
235 * sleep will return immediately with EINTR or EWOULDBLOCK
236 * which will hopefully force them to back out to userland
237 * freeing resources as they go. Any thread attempting
238 * to return to userland will thread_exit() from userret().
239 * thread_exit() will unsuspend us when the last of the
240 * other threads exits.
241 * If there is already a thread singler after resumption,
242 * calling thread_single will fail; in that case, we just
243 * re-check all suspension request, the thread should
244 * either be suspended there or exit.
246 if (!thread_single(p, SINGLE_EXIT))
248 * All other activity in this process is now
249 * stopped. Threading support has been turned
254 * Recheck for new stop or suspend requests which
255 * might appear while process lock was dropped in
258 thread_suspend_check(0);
260 KASSERT(p->p_numthreads == 1,
261 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
262 racct_sub(p, RACCT_NTHR, 1);
264 /* Let event handler change exit status */
269 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
270 * on our vmspace, so we should block below until they have
271 * released their reference to us. Note that if they have
272 * requested S_EXIT stops we will block here until they ack
275 _STOPEVENT(p, S_EXIT, 0);
278 * Ignore any pending request to stop due to a stop signal.
279 * Once P_WEXIT is set, future requests will be ignored as
282 p->p_flag &= ~P_STOPPED_SIG;
283 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
286 * Note that we are exiting and do another wakeup of anyone in
287 * PIOCWAIT in case they aren't listening for S_EXIT stops or
288 * decided to wait again after we told them we are exiting.
290 p->p_flag |= P_WEXIT;
294 * Wait for any processes that have a hold on our vmspace to
295 * release their reference.
297 while (p->p_lock > 0)
298 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
301 /* Drain the limit callout while we don't have the proc locked */
302 callout_drain(&p->p_limco);
306 * The Sun BSM exit token contains two components: an exit status as
307 * passed to exit(), and a return value to indicate what sort of exit
308 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
309 * what the return value is.
311 AUDIT_ARG_EXIT(rval, 0);
312 AUDIT_SYSCALL_EXIT(0, td);
315 /* Are we a task leader with peers? */
316 if (p->p_peers != NULL && p == p->p_leader) {
317 mtx_lock(&ppeers_lock);
321 kern_psignal(q, SIGKILL);
325 while (p->p_peers != NULL)
326 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
327 mtx_unlock(&ppeers_lock);
331 * Check if any loadable modules need anything done at process exit.
332 * E.g. SYSV IPC stuff.
333 * Event handler could change exit status.
334 * XXX what if one of these generates an error?
336 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
339 * If parent is waiting for us to exit or exec,
340 * P_PPWAIT is set; we will wakeup the parent below.
344 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
348 * Stop the real interval timer. If the handler is currently
349 * executing, prevent it from rearming itself and let it finish.
351 if (timevalisset(&p->p_realtimer.it_value) &&
352 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
353 timevalclear(&p->p_realtimer.it_interval);
354 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
355 KASSERT(!timevalisset(&p->p_realtimer.it_value),
356 ("realtime timer is still armed"));
361 umtx_thread_exit(td);
364 * Reset any sigio structures pointing to us as a result of
365 * F_SETOWN with our pid.
367 funsetownlst(&p->p_sigiolst);
370 * If this process has an nlminfo data area (for lockd), release it
372 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
373 (*nlminfo_release_p)(p);
376 * Close open files and release open-file table.
382 * If this thread tickled GEOM, we need to wait for the giggling to
383 * stop before we return to userland
385 if (td->td_pflags & TDP_GEOM)
389 * Remove ourself from our leader's peer list and wake our leader.
391 if (p->p_leader->p_peers != NULL) {
392 mtx_lock(&ppeers_lock);
393 if (p->p_leader->p_peers != NULL) {
395 while (q->p_peers != p)
397 q->p_peers = p->p_peers;
400 mtx_unlock(&ppeers_lock);
405 (void)acct_process(td);
411 * Release reference to text vnode
413 if (p->p_textvp != NULL) {
419 * Release our limits structure.
421 lim_free(p->p_limit);
427 * Call machine-dependent code to release any
428 * machine-dependent resources other than the address space.
429 * The address space is released by "vmspace_exitfree(p)" in
434 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
436 sx_xlock(&proctree_lock);
438 * Remove proc from allproc queue and pidhash chain.
439 * Place onto zombproc. Unlink from parent's child list.
441 sx_xlock(&allproc_lock);
442 LIST_REMOVE(p, p_list);
443 LIST_INSERT_HEAD(&zombproc, p, p_list);
444 LIST_REMOVE(p, p_hash);
445 sx_xunlock(&allproc_lock);
448 * Reparent all children processes:
449 * - traced ones to the original parent (or init if we are that parent)
452 q = LIST_FIRST(&p->p_children);
453 if (q != NULL) /* only need this if any child is S_ZOMB */
455 for (; q != NULL; q = nq) {
456 nq = LIST_NEXT(q, p_sibling);
457 ksi = ksiginfo_alloc(TRUE);
459 q->p_sigparent = SIGCHLD;
461 if (!(q->p_flag & P_TRACED)) {
462 proc_reparent(q, q->p_reaper);
463 if (q->p_state == PRS_ZOMBIE) {
465 * Inform reaper about the reparented
466 * zombie, since wait(2) has something
467 * new to report. Guarantee queueing
468 * of the SIGCHLD signal, similar to
469 * the _exit() behaviour, by providing
470 * our ksiginfo. Ksi is freed by the
473 if (q->p_ksi == NULL) {
476 ksiginfo_copy(q->p_ksi, ksi);
477 ksi->ksi_flags |= KSI_INS;
481 PROC_LOCK(q->p_reaper);
482 pksignal(q->p_reaper, SIGCHLD, ksi1);
483 PROC_UNLOCK(q->p_reaper);
487 * Traced processes are killed since their existence
488 * means someone is screwing up.
490 t = proc_realparent(q);
492 proc_reparent(q, q->p_reaper);
499 * Since q was found on our children list, the
500 * proc_reparent() call moved q to the orphan
501 * list due to present P_TRACED flag. Clear
502 * orphan link for q now while q is locked.
505 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
506 q->p_flag2 &= ~P2_PTRACE_FSTP;
508 FOREACH_THREAD_IN_PROC(q, tdt) {
509 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
512 kern_psignal(q, SIGKILL);
520 * Also get rid of our orphans.
522 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
524 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
530 /* Save exit status. */
536 * Tell the DTrace fasttrap provider about the exit if it
537 * has declared an interest.
539 if (dtrace_fasttrap_exit)
540 dtrace_fasttrap_exit(p);
544 * Notify interested parties of our demise.
546 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
549 int reason = CLD_EXITED;
550 if (WCOREDUMP(signo))
552 else if (WIFSIGNALED(signo))
554 SDT_PROBE1(proc, , , exit, reason);
558 * If this is a process with a descriptor, we may not need to deliver
559 * a signal to the parent. proctree_lock is held over
560 * procdesc_exit() to serialize concurrent calls to close() and
564 if (p->p_procdesc == NULL || procdesc_exit(p)) {
566 * Notify parent that we're gone. If parent has the
567 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
568 * notify process 1 instead (and hope it will handle this
571 PROC_LOCK(p->p_pptr);
572 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
573 if (p->p_pptr->p_sigacts->ps_flag &
574 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
577 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
580 proc_reparent(p, p->p_reaper);
581 p->p_sigparent = SIGCHLD;
582 PROC_LOCK(p->p_pptr);
585 * Notify parent, so in case he was wait(2)ing or
586 * executing waitpid(2) with our pid, he will
591 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
593 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
595 } else if (p->p_sigparent != 0) {
596 if (p->p_sigparent == SIGCHLD) {
598 } else { /* LINUX thread */
603 PROC_LOCK(p->p_pptr);
604 sx_xunlock(&proctree_lock);
606 if (signal_parent == 1) {
608 } else if (signal_parent == 2) {
609 kern_psignal(p->p_pptr, p->p_sigparent);
612 /* Tell the prison that we are gone. */
613 prison_proc_free(p->p_ucred->cr_prison);
616 * The state PRS_ZOMBIE prevents other proesses from sending
617 * signal to the process, to avoid memory leak, we free memory
618 * for signal queue at the time when the state is set.
620 sigqueue_flush(&p->p_sigqueue);
621 sigqueue_flush(&td->td_sigqueue);
624 * We have to wait until after acquiring all locks before
625 * changing p_state. We need to avoid all possible context
626 * switches (including ones from blocking on a mutex) while
627 * marked as a zombie. We also have to set the zombie state
628 * before we release the parent process' proc lock to avoid
629 * a lost wakeup. So, we first call wakeup, then we grab the
630 * sched lock, update the state, and release the parent process'
634 cv_broadcast(&p->p_pwait);
635 sched_exit(p->p_pptr, td);
637 p->p_state = PRS_ZOMBIE;
638 PROC_UNLOCK(p->p_pptr);
641 * Save our children's rusage information in our exit rusage.
644 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
648 * Make sure the scheduler takes this thread out of its tables etc.
649 * This will also release this thread's reference to the ucred.
650 * Other thread parts to release include pcb bits and such.
656 #ifndef _SYS_SYSPROTO_H_
665 sys_abort2(struct thread *td, struct abort2_args *uap)
667 struct proc *p = td->td_proc;
673 * Do it right now so we can log either proper call of abort2(), or
674 * note, that invalid argument was passed. 512 is big enough to
675 * handle 16 arguments' descriptions with additional comments.
677 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
679 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
680 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
682 * Since we can't return from abort2(), send SIGKILL in cases, where
683 * abort2() was called improperly
686 /* Prevent from DoSes from user-space. */
687 if (uap->nargs < 0 || uap->nargs > 16)
689 if (uap->nargs > 0) {
690 if (uap->args == NULL)
692 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
697 * Limit size of 'reason' string to 128. Will fit even when
698 * maximal number of arguments was chosen to be logged.
700 if (uap->why != NULL) {
701 error = sbuf_copyin(sb, uap->why, 128);
705 sbuf_printf(sb, "(null)");
707 if (uap->nargs > 0) {
708 sbuf_printf(sb, "(");
709 for (i = 0;i < uap->nargs; i++)
710 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
711 sbuf_printf(sb, ")");
714 * Final stage: arguments were proper, string has been
715 * successfully copied from userspace, and copying pointers
716 * from user-space succeed.
720 if (sig == SIGKILL) {
722 sbuf_printf(sb, " (Reason text inaccessible)");
726 log(LOG_INFO, "%s", sbuf_data(sb));
735 * The dirty work is handled by kern_wait().
738 owait(struct thread *td, struct owait_args *uap __unused)
742 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
744 td->td_retval[1] = status;
747 #endif /* COMPAT_43 */
750 * The dirty work is handled by kern_wait().
753 sys_wait4(struct thread *td, struct wait4_args *uap)
755 struct rusage ru, *rup;
758 if (uap->rusage != NULL)
762 error = kern_wait(td, uap->pid, &status, uap->options, rup);
763 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
764 error = copyout(&status, uap->status, sizeof(status));
765 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
766 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
771 sys_wait6(struct thread *td, struct wait6_args *uap)
773 struct __wrusage wru, *wrup;
779 idtype = uap->idtype;
782 if (uap->wrusage != NULL)
787 if (uap->info != NULL) {
789 bzero(sip, sizeof(*sip));
794 * We expect all callers of wait6() to know about WEXITED and
797 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
799 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
800 error = copyout(&status, uap->status, sizeof(status));
801 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
802 error = copyout(&wru, uap->wrusage, sizeof(wru));
803 if (uap->info != NULL && error == 0)
804 error = copyout(&si, uap->info, sizeof(si));
809 * Reap the remains of a zombie process and optionally return status and
810 * rusage. Asserts and will release both the proctree_lock and the process
811 * lock as part of its work.
814 proc_reap(struct thread *td, struct proc *p, int *status, int options)
818 sx_assert(&proctree_lock, SA_XLOCKED);
819 PROC_LOCK_ASSERT(p, MA_OWNED);
820 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
822 mtx_spin_wait_unlocked(&p->p_slock);
827 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
828 if (options & WNOWAIT) {
830 * Only poll, returning the status. Caller does not wish to
831 * release the proc struct just yet.
834 sx_xunlock(&proctree_lock);
839 sigqueue_take(p->p_ksi);
843 * If we got the child via a ptrace 'attach', we need to give it back
846 if (p->p_oppid != 0 && p->p_oppid != p->p_pptr->p_pid) {
848 t = proc_realparent(p);
852 "wait: traced child %d moved back to parent %d", p->p_pid,
857 pksignal(t, SIGCHLD, p->p_ksi);
859 cv_broadcast(&p->p_pwait);
861 sx_xunlock(&proctree_lock);
868 * Remove other references to this process to ensure we have an
869 * exclusive reference.
871 sx_xlock(&allproc_lock);
872 LIST_REMOVE(p, p_list); /* off zombproc */
873 sx_xunlock(&allproc_lock);
874 LIST_REMOVE(p, p_sibling);
875 reaper_abandon_children(p, true);
876 LIST_REMOVE(p, p_reapsibling);
881 if (p->p_procdesc != NULL)
883 sx_xunlock(&proctree_lock);
886 knlist_detach(p->p_klist);
891 * Removal from allproc list and process group list paired with
892 * PROC_LOCK which was executed during that time should guarantee
893 * nothing can reach this process anymore. As such further locking
896 p->p_xexit = p->p_xsig = 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.
913 racct_sub(p, RACCT_NPROC, 1);
920 * Free credentials, arguments, and sigacts.
923 proc_set_cred(p, NULL);
924 pargs_drop(p->p_args);
926 sigacts_free(p->p_sigacts);
930 * Do any thread-system specific cleanups.
935 * Give vm and machine-dependent layer a chance to free anything that
936 * cpu_exit couldn't release while still running in process context.
943 KASSERT(FIRST_THREAD_IN_PROC(p),
944 ("proc_reap: no residual thread!"));
945 uma_zfree(proc_zone, p);
946 atomic_add_int(&nprocs, -1);
950 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
951 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
956 sx_assert(&proctree_lock, SA_XLOCKED);
962 if (p->p_procdesc != NULL) {
968 if (p->p_pid != (pid_t)id) {
974 if (p->p_pgid != (pid_t)id) {
980 if (p->p_session->s_sid != (pid_t)id) {
986 if (p->p_ucred->cr_uid != (uid_t)id) {
992 if (p->p_ucred->cr_gid != (gid_t)id) {
998 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1004 * It seems that the thread structures get zeroed out
1005 * at process exit. This makes it impossible to
1006 * support P_SETID, P_CID or P_CPUID.
1013 if (p_canwait(td, p)) {
1018 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1024 * This special case handles a kthread spawned by linux_clone
1025 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1026 * functions need to be able to distinguish between waiting
1027 * on a process and waiting on a thread. It is a thread if
1028 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1029 * signifies we want to wait for threads and not processes.
1031 if ((p->p_sigparent != SIGCHLD) ^
1032 ((options & WLINUXCLONE) != 0)) {
1037 if (siginfo != NULL) {
1038 bzero(siginfo, sizeof(*siginfo));
1039 siginfo->si_errno = 0;
1042 * SUSv4 requires that the si_signo value is always
1043 * SIGCHLD. Obey it despite the rfork(2) interface
1044 * allows to request other signal for child exit
1047 siginfo->si_signo = SIGCHLD;
1050 * This is still a rough estimate. We will fix the
1051 * cases TRAPPED, STOPPED, and CONTINUED later.
1053 if (WCOREDUMP(p->p_xsig)) {
1054 siginfo->si_code = CLD_DUMPED;
1055 siginfo->si_status = WTERMSIG(p->p_xsig);
1056 } else if (WIFSIGNALED(p->p_xsig)) {
1057 siginfo->si_code = CLD_KILLED;
1058 siginfo->si_status = WTERMSIG(p->p_xsig);
1060 siginfo->si_code = CLD_EXITED;
1061 siginfo->si_status = p->p_xexit;
1064 siginfo->si_pid = p->p_pid;
1065 siginfo->si_uid = p->p_ucred->cr_uid;
1068 * The si_addr field would be useful additional
1069 * detail, but apparently the PC value may be lost
1070 * when we reach this point. bzero() above sets
1071 * siginfo->si_addr to NULL.
1076 * There should be no reason to limit resources usage info to
1077 * exited processes only. A snapshot about any resources used
1078 * by a stopped process may be exactly what is needed.
1080 if (wrusage != NULL) {
1081 rup = &wrusage->wru_self;
1084 calcru(p, &rup->ru_utime, &rup->ru_stime);
1087 rup = &wrusage->wru_children;
1088 *rup = p->p_stats->p_cru;
1089 calccru(p, &rup->ru_utime, &rup->ru_stime);
1092 if (p->p_state == PRS_ZOMBIE && !check_only) {
1093 proc_reap(td, p, status, options);
1100 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1101 struct rusage *rusage)
1103 struct __wrusage wru, *wrup;
1109 * Translate the special pid values into the (idtype, pid)
1110 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1111 * kern_wait6() on its own.
1113 if (pid == WAIT_ANY) {
1116 } else if (pid < 0) {
1130 * For backward compatibility we implicitly add flags WEXITED
1131 * and WTRAPPED here.
1133 options |= WEXITED | WTRAPPED;
1134 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1136 *rusage = wru.wru_self;
1141 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1142 int *status, int options, int si_code)
1146 PROC_LOCK_ASSERT(p, MA_OWNED);
1147 sx_assert(&proctree_lock, SA_XLOCKED);
1148 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1149 si_code == CLD_CONTINUED);
1151 cont = si_code == CLD_CONTINUED;
1152 if ((options & WNOWAIT) == 0) {
1154 p->p_flag &= ~P_CONTINUED;
1156 p->p_flag |= P_WAITED;
1157 PROC_LOCK(td->td_proc);
1158 sigqueue_take(p->p_ksi);
1159 PROC_UNLOCK(td->td_proc);
1161 sx_xunlock(&proctree_lock);
1162 if (siginfo != NULL) {
1163 siginfo->si_code = si_code;
1164 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1167 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1169 td->td_retval[0] = p->p_pid;
1173 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1174 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1178 int error, nfound, ret;
1181 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1182 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1183 AUDIT_ARG_VALUE(options);
1187 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1189 id = (id_t)q->p_pgid;
1194 /* If we don't know the option, just return. */
1195 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1196 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1198 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1200 * We will be unable to find any matching processes,
1201 * because there are no known events to look for.
1202 * Prefer to return error instead of blocking
1209 if (q->p_flag & P_STATCHILD) {
1211 q->p_flag &= ~P_STATCHILD;
1214 sx_xlock(&proctree_lock);
1217 LIST_FOREACH(p, &q->p_children, p_sibling) {
1219 ret = proc_to_reap(td, p, idtype, id, status, options,
1220 wrusage, siginfo, 0);
1223 else if (ret != 1) {
1224 td->td_retval[0] = pid;
1229 PROC_LOCK_ASSERT(p, MA_OWNED);
1231 if ((options & WTRAPPED) != 0 &&
1232 (p->p_flag & P_TRACED) != 0) {
1235 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1236 p->p_suspcount == p->p_numthreads &&
1237 (p->p_flag & P_WAITED) == 0);
1241 "wait: returning trapped pid %d status %#x "
1242 "(xstat %d) xthread %d",
1243 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1244 p->p_xthread != NULL ?
1245 p->p_xthread->td_tid : -1);
1246 report_alive_proc(td, p, siginfo, status,
1247 options, CLD_TRAPPED);
1251 if ((options & WUNTRACED) != 0 &&
1252 (p->p_flag & P_STOPPED_SIG) != 0) {
1254 report = (p->p_suspcount == p->p_numthreads &&
1255 ((p->p_flag & P_WAITED) == 0));
1258 report_alive_proc(td, p, siginfo, status,
1259 options, CLD_STOPPED);
1263 if ((options & WCONTINUED) != 0 &&
1264 (p->p_flag & P_CONTINUED) != 0) {
1265 report_alive_proc(td, p, siginfo, status, options,
1273 * Look in the orphans list too, to allow the parent to
1274 * collect it's child exit status even if child is being
1277 * Debugger detaches from the parent upon successful
1278 * switch-over from parent to child. At this point due to
1279 * re-parenting the parent loses the child to debugger and a
1280 * wait4(2) call would report that it has no children to wait
1281 * for. By maintaining a list of orphans we allow the parent
1282 * to successfully wait until the child becomes a zombie.
1285 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1286 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1289 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1290 (int)td->td_retval[0]));
1298 sx_xunlock(&proctree_lock);
1301 if (options & WNOHANG) {
1302 sx_xunlock(&proctree_lock);
1303 td->td_retval[0] = 0;
1307 if (q->p_flag & P_STATCHILD) {
1308 q->p_flag &= ~P_STATCHILD;
1312 sx_xunlock(&proctree_lock);
1313 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1320 * Make process 'parent' the new parent of process 'child'.
1321 * Must be called with an exclusive hold of proctree lock.
1324 proc_reparent(struct proc *child, struct proc *parent)
1327 sx_assert(&proctree_lock, SX_XLOCKED);
1328 PROC_LOCK_ASSERT(child, MA_OWNED);
1329 if (child->p_pptr == parent)
1332 PROC_LOCK(child->p_pptr);
1333 sigqueue_take(child->p_ksi);
1334 PROC_UNLOCK(child->p_pptr);
1335 LIST_REMOVE(child, p_sibling);
1336 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1338 clear_orphan(child);
1339 if (child->p_flag & P_TRACED) {
1340 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1341 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1342 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1345 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1348 child->p_treeflag |= P_TREE_ORPHANED;
1351 child->p_pptr = parent;