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
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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
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_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);
361 * Reset any sigio structures pointing to us as a result of
362 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
364 funsetownlst(&p->p_sigiolst);
367 * Close open files and release open-file table.
374 * If this thread tickled GEOM, we need to wait for the giggling to
375 * stop before we return to userland
377 if (td->td_pflags & TDP_GEOM)
381 * Remove ourself from our leader's peer list and wake our leader.
383 if (p->p_leader->p_peers != NULL) {
384 mtx_lock(&ppeers_lock);
385 if (p->p_leader->p_peers != NULL) {
387 while (q->p_peers != p)
389 q->p_peers = p->p_peers;
392 mtx_unlock(&ppeers_lock);
396 (void)acct_process(td);
402 * Release reference to text vnode
404 if (p->p_textvp != NULL) {
410 * Release our limits structure.
412 lim_free(p->p_limit);
418 * Call machine-dependent code to release any
419 * machine-dependent resources other than the address space.
420 * The address space is released by "vmspace_exitfree(p)" in
425 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
428 * Remove from allproc. It still sits in the hash.
430 sx_xlock(&allproc_lock);
431 LIST_REMOVE(p, p_list);
432 sx_xunlock(&allproc_lock);
434 sx_xlock(&proctree_lock);
436 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
440 * killjobc() might drop and re-acquire proctree_lock to
441 * revoke control tty if exiting process was a session leader.
446 * Reparent all children processes:
447 * - traced ones to the original parent (or init if we are that parent)
450 q = LIST_FIRST(&p->p_children);
451 if (q != NULL) /* only need this if any child is S_ZOMB */
453 for (; q != NULL; q = nq) {
454 nq = LIST_NEXT(q, p_sibling);
455 ksi = ksiginfo_alloc(TRUE);
457 q->p_sigparent = SIGCHLD;
459 if ((q->p_flag & P_TRACED) == 0) {
460 proc_reparent(q, q->p_reaper, true);
461 if (q->p_state == PRS_ZOMBIE) {
463 * Inform reaper about the reparented
464 * zombie, since wait(2) has something
465 * new to report. Guarantee queueing
466 * of the SIGCHLD signal, similar to
467 * the _exit() behaviour, by providing
468 * our ksiginfo. Ksi is freed by the
471 if (q->p_ksi == NULL) {
474 ksiginfo_copy(q->p_ksi, ksi);
475 ksi->ksi_flags |= KSI_INS;
479 PROC_LOCK(q->p_reaper);
480 pksignal(q->p_reaper, SIGCHLD, ksi1);
481 PROC_UNLOCK(q->p_reaper);
482 } else if (q->p_pdeathsig > 0) {
484 * The child asked to received a signal
487 kern_psignal(q, q->p_pdeathsig);
491 * Traced processes are killed since their existence
492 * means someone is screwing up.
494 t = proc_realparent(q);
496 proc_reparent(q, q->p_reaper, true);
499 proc_reparent(q, t, true);
503 * Since q was found on our children list, the
504 * proc_reparent() call moved q to the orphan
505 * list due to present P_TRACED flag. Clear
506 * orphan link for q now while q is locked.
508 proc_clear_orphan(q);
509 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
510 q->p_flag2 &= ~P2_PTRACE_FSTP;
512 FOREACH_THREAD_IN_PROC(q, tdt) {
513 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
516 kern_psignal(q, SIGKILL);
524 * Also get rid of our orphans.
526 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
528 KASSERT(q->p_oppid == p->p_pid,
529 ("orphan %p of %p has unexpected oppid %d", q, p,
531 q->p_oppid = q->p_reaper->p_pid;
534 * If we are the real parent of this process
535 * but it has been reparented to a debugger, then
536 * check if it asked for a signal when we exit.
538 if (q->p_pdeathsig > 0)
539 kern_psignal(q, q->p_pdeathsig);
540 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
542 proc_clear_orphan(q);
547 if (SDT_PROBES_ENABLED()) {
548 int reason = CLD_EXITED;
549 if (WCOREDUMP(signo))
551 else if (WIFSIGNALED(signo))
553 SDT_PROBE1(proc, , , exit, reason);
557 /* Save exit status. */
563 * Tell the DTrace fasttrap provider about the exit if it
564 * has declared an interest.
566 if (dtrace_fasttrap_exit)
567 dtrace_fasttrap_exit(p);
571 * Notify interested parties of our demise.
573 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
576 * If this is a process with a descriptor, we may not need to deliver
577 * a signal to the parent. proctree_lock is held over
578 * procdesc_exit() to serialize concurrent calls to close() and
582 if (p->p_procdesc == NULL || procdesc_exit(p)) {
584 * Notify parent that we're gone. If parent has the
585 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
586 * notify process 1 instead (and hope it will handle this
589 PROC_LOCK(p->p_pptr);
590 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
591 if (p->p_pptr->p_sigacts->ps_flag &
592 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
595 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
598 proc_reparent(p, p->p_reaper, true);
599 p->p_sigparent = SIGCHLD;
600 PROC_LOCK(p->p_pptr);
603 * Notify parent, so in case he was wait(2)ing or
604 * executing waitpid(2) with our pid, he will
609 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
611 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
613 } else if (p->p_sigparent != 0) {
614 if (p->p_sigparent == SIGCHLD) {
616 } else { /* LINUX thread */
621 PROC_LOCK(p->p_pptr);
622 sx_xunlock(&proctree_lock);
624 if (signal_parent == 1) {
626 } else if (signal_parent == 2) {
627 kern_psignal(p->p_pptr, p->p_sigparent);
630 /* Tell the prison that we are gone. */
631 prison_proc_free(p->p_ucred->cr_prison);
634 * The state PRS_ZOMBIE prevents other proesses from sending
635 * signal to the process, to avoid memory leak, we free memory
636 * for signal queue at the time when the state is set.
638 sigqueue_flush(&p->p_sigqueue);
639 sigqueue_flush(&td->td_sigqueue);
642 * We have to wait until after acquiring all locks before
643 * changing p_state. We need to avoid all possible context
644 * switches (including ones from blocking on a mutex) while
645 * marked as a zombie. We also have to set the zombie state
646 * before we release the parent process' proc lock to avoid
647 * a lost wakeup. So, we first call wakeup, then we grab the
648 * sched lock, update the state, and release the parent process'
652 cv_broadcast(&p->p_pwait);
653 sched_exit(p->p_pptr, td);
655 p->p_state = PRS_ZOMBIE;
656 PROC_UNLOCK(p->p_pptr);
659 * Save our children's rusage information in our exit rusage.
662 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
666 * Make sure the scheduler takes this thread out of its tables etc.
667 * This will also release this thread's reference to the ucred.
668 * Other thread parts to release include pcb bits and such.
673 #ifndef _SYS_SYSPROTO_H_
682 sys_abort2(struct thread *td, struct abort2_args *uap)
684 struct proc *p = td->td_proc;
690 * Do it right now so we can log either proper call of abort2(), or
691 * note, that invalid argument was passed. 512 is big enough to
692 * handle 16 arguments' descriptions with additional comments.
694 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
696 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
697 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
699 * Since we can't return from abort2(), send SIGKILL in cases, where
700 * abort2() was called improperly
703 /* Prevent from DoSes from user-space. */
704 if (uap->nargs < 0 || uap->nargs > 16)
706 if (uap->nargs > 0) {
707 if (uap->args == NULL)
709 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
714 * Limit size of 'reason' string to 128. Will fit even when
715 * maximal number of arguments was chosen to be logged.
717 if (uap->why != NULL) {
718 error = sbuf_copyin(sb, uap->why, 128);
722 sbuf_printf(sb, "(null)");
724 if (uap->nargs > 0) {
725 sbuf_printf(sb, "(");
726 for (i = 0;i < uap->nargs; i++)
727 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
728 sbuf_printf(sb, ")");
731 * Final stage: arguments were proper, string has been
732 * successfully copied from userspace, and copying pointers
733 * from user-space succeed.
737 if (sig == SIGKILL) {
739 sbuf_printf(sb, " (Reason text inaccessible)");
743 log(LOG_INFO, "%s", sbuf_data(sb));
751 * The dirty work is handled by kern_wait().
754 owait(struct thread *td, struct owait_args *uap __unused)
758 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
760 td->td_retval[1] = status;
763 #endif /* COMPAT_43 */
766 * The dirty work is handled by kern_wait().
769 sys_wait4(struct thread *td, struct wait4_args *uap)
771 struct rusage ru, *rup;
774 if (uap->rusage != NULL)
778 error = kern_wait(td, uap->pid, &status, uap->options, rup);
779 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
780 error = copyout(&status, uap->status, sizeof(status));
781 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
782 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
787 sys_wait6(struct thread *td, struct wait6_args *uap)
789 struct __wrusage wru, *wrup;
795 idtype = uap->idtype;
798 if (uap->wrusage != NULL)
803 if (uap->info != NULL) {
805 bzero(sip, sizeof(*sip));
810 * We expect all callers of wait6() to know about WEXITED and
813 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
815 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
816 error = copyout(&status, uap->status, sizeof(status));
817 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
818 error = copyout(&wru, uap->wrusage, sizeof(wru));
819 if (uap->info != NULL && error == 0)
820 error = copyout(&si, uap->info, sizeof(si));
825 * Reap the remains of a zombie process and optionally return status and
826 * rusage. Asserts and will release both the proctree_lock and the process
827 * lock as part of its work.
830 proc_reap(struct thread *td, struct proc *p, int *status, int options)
834 sx_assert(&proctree_lock, SA_XLOCKED);
835 PROC_LOCK_ASSERT(p, MA_OWNED);
836 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
838 mtx_spin_wait_unlocked(&p->p_slock);
843 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
844 if (options & WNOWAIT) {
846 * Only poll, returning the status. Caller does not wish to
847 * release the proc struct just yet.
850 sx_xunlock(&proctree_lock);
855 sigqueue_take(p->p_ksi);
859 * If we got the child via a ptrace 'attach', we need to give it back
862 if (p->p_oppid != p->p_pptr->p_pid) {
864 t = proc_realparent(p);
868 "wait: traced child %d moved back to parent %d", p->p_pid,
870 proc_reparent(p, t, false);
872 pksignal(t, SIGCHLD, p->p_ksi);
874 cv_broadcast(&p->p_pwait);
876 sx_xunlock(&proctree_lock);
882 * Remove other references to this process to ensure we have an
883 * exclusive reference.
885 sx_xlock(PIDHASHLOCK(p->p_pid));
886 LIST_REMOVE(p, p_hash);
887 sx_xunlock(PIDHASHLOCK(p->p_pid));
888 LIST_REMOVE(p, p_sibling);
889 reaper_abandon_children(p, true);
892 proc_clear_orphan(p);
895 if (p->p_procdesc != NULL)
897 sx_xunlock(&proctree_lock);
899 proc_id_clear(PROC_ID_PID, p->p_pid);
902 knlist_detach(p->p_klist);
907 * Removal from allproc list and process group list paired with
908 * PROC_LOCK which was executed during that time should guarantee
909 * nothing can reach this process anymore. As such further locking
912 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
915 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
919 * Decrement the count of procs running with this uid.
921 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
924 * Destroy resource accounting information associated with the process.
929 racct_sub(p, RACCT_NPROC, 1);
936 * Free credentials, arguments, and sigacts.
939 pargs_drop(p->p_args);
941 sigacts_free(p->p_sigacts);
945 * Do any thread-system specific cleanups.
950 * Give vm and machine-dependent layer a chance to free anything that
951 * cpu_exit couldn't release while still running in process context.
958 KASSERT(FIRST_THREAD_IN_PROC(p),
959 ("proc_reap: no residual thread!"));
960 uma_zfree(proc_zone, p);
961 atomic_add_int(&nprocs, -1);
965 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
966 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
971 sx_assert(&proctree_lock, SA_XLOCKED);
977 if (p->p_procdesc == NULL ||
978 (p->p_pptr == td->td_proc &&
979 (p->p_flag & P_TRACED) != 0)) {
986 if (p->p_pid != (pid_t)id) {
992 if (p->p_pgid != (pid_t)id) {
998 if (p->p_session->s_sid != (pid_t)id) {
1004 if (p->p_ucred->cr_uid != (uid_t)id) {
1010 if (p->p_ucred->cr_gid != (gid_t)id) {
1016 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1022 * It seems that the thread structures get zeroed out
1023 * at process exit. This makes it impossible to
1024 * support P_SETID, P_CID or P_CPUID.
1031 if (p_canwait(td, p)) {
1036 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1042 * This special case handles a kthread spawned by linux_clone
1043 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1044 * functions need to be able to distinguish between waiting
1045 * on a process and waiting on a thread. It is a thread if
1046 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1047 * signifies we want to wait for threads and not processes.
1049 if ((p->p_sigparent != SIGCHLD) ^
1050 ((options & WLINUXCLONE) != 0)) {
1055 if (siginfo != NULL) {
1056 bzero(siginfo, sizeof(*siginfo));
1057 siginfo->si_errno = 0;
1060 * SUSv4 requires that the si_signo value is always
1061 * SIGCHLD. Obey it despite the rfork(2) interface
1062 * allows to request other signal for child exit
1065 siginfo->si_signo = SIGCHLD;
1068 * This is still a rough estimate. We will fix the
1069 * cases TRAPPED, STOPPED, and CONTINUED later.
1071 if (WCOREDUMP(p->p_xsig)) {
1072 siginfo->si_code = CLD_DUMPED;
1073 siginfo->si_status = WTERMSIG(p->p_xsig);
1074 } else if (WIFSIGNALED(p->p_xsig)) {
1075 siginfo->si_code = CLD_KILLED;
1076 siginfo->si_status = WTERMSIG(p->p_xsig);
1078 siginfo->si_code = CLD_EXITED;
1079 siginfo->si_status = p->p_xexit;
1082 siginfo->si_pid = p->p_pid;
1083 siginfo->si_uid = p->p_ucred->cr_uid;
1086 * The si_addr field would be useful additional
1087 * detail, but apparently the PC value may be lost
1088 * when we reach this point. bzero() above sets
1089 * siginfo->si_addr to NULL.
1094 * There should be no reason to limit resources usage info to
1095 * exited processes only. A snapshot about any resources used
1096 * by a stopped process may be exactly what is needed.
1098 if (wrusage != NULL) {
1099 rup = &wrusage->wru_self;
1102 calcru(p, &rup->ru_utime, &rup->ru_stime);
1105 rup = &wrusage->wru_children;
1106 *rup = p->p_stats->p_cru;
1107 calccru(p, &rup->ru_utime, &rup->ru_stime);
1110 if (p->p_state == PRS_ZOMBIE && !check_only) {
1111 proc_reap(td, p, status, options);
1118 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1119 struct rusage *rusage)
1121 struct __wrusage wru, *wrup;
1127 * Translate the special pid values into the (idtype, pid)
1128 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1129 * kern_wait6() on its own.
1131 if (pid == WAIT_ANY) {
1134 } else if (pid < 0) {
1148 * For backward compatibility we implicitly add flags WEXITED
1149 * and WTRAPPED here.
1151 options |= WEXITED | WTRAPPED;
1152 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1154 *rusage = wru.wru_self;
1159 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1160 int *status, int options, int si_code)
1164 PROC_LOCK_ASSERT(p, MA_OWNED);
1165 sx_assert(&proctree_lock, SA_XLOCKED);
1166 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1167 si_code == CLD_CONTINUED);
1169 cont = si_code == CLD_CONTINUED;
1170 if ((options & WNOWAIT) == 0) {
1172 p->p_flag &= ~P_CONTINUED;
1174 p->p_flag |= P_WAITED;
1175 PROC_LOCK(td->td_proc);
1176 sigqueue_take(p->p_ksi);
1177 PROC_UNLOCK(td->td_proc);
1179 sx_xunlock(&proctree_lock);
1180 if (siginfo != NULL) {
1181 siginfo->si_code = si_code;
1182 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1185 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1187 td->td_retval[0] = p->p_pid;
1191 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1192 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1196 int error, nfound, ret;
1199 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1200 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1201 AUDIT_ARG_VALUE(options);
1205 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1207 id = (id_t)q->p_pgid;
1212 /* If we don't know the option, just return. */
1213 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1214 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1216 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1218 * We will be unable to find any matching processes,
1219 * because there are no known events to look for.
1220 * Prefer to return error instead of blocking
1227 if (q->p_flag & P_STATCHILD) {
1229 q->p_flag &= ~P_STATCHILD;
1232 sx_xlock(&proctree_lock);
1235 LIST_FOREACH(p, &q->p_children, p_sibling) {
1237 ret = proc_to_reap(td, p, idtype, id, status, options,
1238 wrusage, siginfo, 0);
1241 else if (ret != 1) {
1242 td->td_retval[0] = pid;
1247 PROC_LOCK_ASSERT(p, MA_OWNED);
1249 if ((options & WTRAPPED) != 0 &&
1250 (p->p_flag & P_TRACED) != 0) {
1253 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1254 p->p_suspcount == p->p_numthreads &&
1255 (p->p_flag & P_WAITED) == 0);
1259 "wait: returning trapped pid %d status %#x "
1260 "(xstat %d) xthread %d",
1261 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1262 p->p_xthread != NULL ?
1263 p->p_xthread->td_tid : -1);
1264 report_alive_proc(td, p, siginfo, status,
1265 options, CLD_TRAPPED);
1269 if ((options & WUNTRACED) != 0 &&
1270 (p->p_flag & P_STOPPED_SIG) != 0) {
1272 report = (p->p_suspcount == p->p_numthreads &&
1273 ((p->p_flag & P_WAITED) == 0));
1276 report_alive_proc(td, p, siginfo, status,
1277 options, CLD_STOPPED);
1281 if ((options & WCONTINUED) != 0 &&
1282 (p->p_flag & P_CONTINUED) != 0) {
1283 report_alive_proc(td, p, siginfo, status, options,
1291 * Look in the orphans list too, to allow the parent to
1292 * collect it's child exit status even if child is being
1295 * Debugger detaches from the parent upon successful
1296 * switch-over from parent to child. At this point due to
1297 * re-parenting the parent loses the child to debugger and a
1298 * wait4(2) call would report that it has no children to wait
1299 * for. By maintaining a list of orphans we allow the parent
1300 * to successfully wait until the child becomes a zombie.
1303 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1304 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1307 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1308 (int)td->td_retval[0]));
1316 sx_xunlock(&proctree_lock);
1319 if (options & WNOHANG) {
1320 sx_xunlock(&proctree_lock);
1321 td->td_retval[0] = 0;
1325 if (q->p_flag & P_STATCHILD) {
1326 q->p_flag &= ~P_STATCHILD;
1330 sx_xunlock(&proctree_lock);
1331 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1338 proc_add_orphan(struct proc *child, struct proc *parent)
1341 sx_assert(&proctree_lock, SX_XLOCKED);
1342 KASSERT((child->p_flag & P_TRACED) != 0,
1343 ("proc_add_orphan: not traced"));
1345 if (LIST_EMPTY(&parent->p_orphans)) {
1346 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1347 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1349 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1352 child->p_treeflag |= P_TREE_ORPHANED;
1356 * Make process 'parent' the new parent of process 'child'.
1357 * Must be called with an exclusive hold of proctree lock.
1360 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1363 sx_assert(&proctree_lock, SX_XLOCKED);
1364 PROC_LOCK_ASSERT(child, MA_OWNED);
1365 if (child->p_pptr == parent)
1368 PROC_LOCK(child->p_pptr);
1369 sigqueue_take(child->p_ksi);
1370 PROC_UNLOCK(child->p_pptr);
1371 LIST_REMOVE(child, p_sibling);
1372 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1374 proc_clear_orphan(child);
1375 if ((child->p_flag & P_TRACED) != 0) {
1376 proc_add_orphan(child, child->p_pptr);
1379 child->p_pptr = parent;
1381 child->p_oppid = parent->p_pid;