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.
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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
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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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>
79 #include <sys/umtxvar.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_XLOCKED);
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_onexit(struct proc *p)
201 MPASS(p->p_numthreads == 1);
202 umtx_thread_exit(FIRST_THREAD_IN_PROC(p));
206 * exit -- death of process.
209 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
212 exit1(td, uap->rval, 0);
217 proc_set_p2_wexit(struct proc *p)
219 PROC_LOCK_ASSERT(p, MA_OWNED);
220 p->p_flag2 |= P2_WEXIT;
221 while (p->p_singlethr > 0)
222 msleep(&p->p_singlethr, &p->p_mtx, PWAIT | PCATCH, "exit1t", 0);
226 * Exit: deallocate address space and other resources, change proc state to
227 * zombie, and unlink proc from allproc and parent's lists. Save exit status
228 * and rusage for wait(). Check for child processes and orphan them.
231 exit1(struct thread *td, int rval, int signo)
233 struct proc *p, *nq, *q, *t;
235 ksiginfo_t *ksi, *ksi1;
238 mtx_assert(&Giant, MA_NOTOWNED);
239 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
240 TSPROCEXIT(td->td_proc->p_pid);
244 * XXX in case we're rebooting we just let init die in order to
245 * work around an unsolved stack overflow seen very late during
246 * shutdown on sparc64 when the gmirror worker process exists.
247 * XXX what to do now that sparc64 is gone... remove if?
249 if (p == initproc && rebooting == 0) {
250 printf("init died (signal %d, exit %d)\n", signo, rval);
251 panic("Going nowhere without my init!");
255 * Deref SU mp, since the thread does not return to userspace.
257 td_softdep_cleanup(td);
260 * MUST abort all other threads before proceeding past here.
263 proc_set_p2_wexit(p);
266 * First check if some other thread or external request got
267 * here before us. If so, act appropriately: exit or suspend.
268 * We must ensure that stop requests are handled before we set
271 thread_suspend_check(0);
272 while (p->p_flag & P_HADTHREADS) {
274 * Kill off the other threads. This requires
275 * some co-operation from other parts of the kernel
276 * so it may not be instantaneous. With this state set
277 * any thread attempting to interruptibly
278 * sleep will return immediately with EINTR or EWOULDBLOCK
279 * which will hopefully force them to back out to userland
280 * freeing resources as they go. Any thread attempting
281 * to return to userland will thread_exit() from ast().
282 * thread_exit() will unsuspend us when the last of the
283 * other threads exits.
284 * If there is already a thread singler after resumption,
285 * calling thread_single() will fail; in that case, we just
286 * re-check all suspension request, the thread should
287 * either be suspended there or exit.
289 if (!thread_single(p, SINGLE_EXIT))
291 * All other activity in this process is now
292 * stopped. Threading support has been turned
297 * Recheck for new stop or suspend requests which
298 * might appear while process lock was dropped in
301 thread_suspend_check(0);
303 KASSERT(p->p_numthreads == 1,
304 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
305 racct_sub(p, RACCT_NTHR, 1);
307 /* Let event handler change exit status */
312 * Ignore any pending request to stop due to a stop signal.
313 * Once P_WEXIT is set, future requests will be ignored as
316 p->p_flag &= ~P_STOPPED_SIG;
317 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
319 /* Note that we are exiting. */
320 p->p_flag |= P_WEXIT;
323 * Wait for any processes that have a hold on our vmspace to
324 * release their reference.
326 while (p->p_lock > 0)
327 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
330 /* Drain the limit callout while we don't have the proc locked */
331 callout_drain(&p->p_limco);
335 * The Sun BSM exit token contains two components: an exit status as
336 * passed to exit(), and a return value to indicate what sort of exit
337 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
338 * what the return value is.
340 AUDIT_ARG_EXIT(rval, 0);
341 AUDIT_SYSCALL_EXIT(0, td);
344 /* Are we a task leader with peers? */
345 if (p->p_peers != NULL && p == p->p_leader) {
346 mtx_lock(&ppeers_lock);
350 kern_psignal(q, SIGKILL);
354 while (p->p_peers != NULL)
355 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
356 mtx_unlock(&ppeers_lock);
362 * Check if any loadable modules need anything done at process exit.
363 * E.g. SYSV IPC stuff.
364 * Event handler could change exit status.
365 * XXX what if one of these generates an error?
367 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
370 * If parent is waiting for us to exit or exec,
371 * P_PPWAIT is set; we will wakeup the parent below.
378 * Stop the real interval timer. If the handler is currently
379 * executing, prevent it from rearming itself and let it finish.
381 if (timevalisset(&p->p_realtimer.it_value) &&
382 callout_stop(&p->p_itcallout) == 0) {
383 timevalclear(&p->p_realtimer.it_interval);
385 callout_drain(&p->p_itcallout);
390 if (p->p_sysent->sv_onexit != NULL)
391 p->p_sysent->sv_onexit(p);
395 * Reset any sigio structures pointing to us as a result of
396 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
398 funsetownlst(&p->p_sigiolst);
401 * Close open files and release open-file table.
408 * If this thread tickled GEOM, we need to wait for the giggling to
409 * stop before we return to userland
411 if (td->td_pflags & TDP_GEOM)
415 * Remove ourself from our leader's peer list and wake our leader.
417 if (p->p_leader->p_peers != NULL) {
418 mtx_lock(&ppeers_lock);
419 if (p->p_leader->p_peers != NULL) {
421 while (q->p_peers != p)
423 q->p_peers = p->p_peers;
426 mtx_unlock(&ppeers_lock);
429 exec_free_abi_mappings(p);
431 (void)acct_process(td);
437 * Release reference to text vnode etc
439 if (p->p_textvp != NULL) {
443 if (p->p_textdvp != NULL) {
447 if (p->p_binname != NULL) {
448 free(p->p_binname, M_PARGS);
453 * Release our limits structure.
455 lim_free(p->p_limit);
461 * Call machine-dependent code to release any
462 * machine-dependent resources other than the address space.
463 * The address space is released by "vmspace_exitfree(p)" in
468 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
471 * Remove from allproc. It still sits in the hash.
473 sx_xlock(&allproc_lock);
474 LIST_REMOVE(p, p_list);
478 * Used by ddb's 'ps' command to find this process via the
481 p->p_list.le_prev = NULL;
483 sx_xunlock(&allproc_lock);
485 sx_xlock(&proctree_lock);
487 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
491 * killjobc() might drop and re-acquire proctree_lock to
492 * revoke control tty if exiting process was a session leader.
497 * Reparent all children processes:
498 * - traced ones to the original parent (or init if we are that parent)
501 q = LIST_FIRST(&p->p_children);
502 if (q != NULL) /* only need this if any child is S_ZOMB */
504 for (; q != NULL; q = nq) {
505 nq = LIST_NEXT(q, p_sibling);
506 ksi = ksiginfo_alloc(M_WAITOK);
508 q->p_sigparent = SIGCHLD;
510 if ((q->p_flag & P_TRACED) == 0) {
511 proc_reparent(q, q->p_reaper, true);
512 if (q->p_state == PRS_ZOMBIE) {
514 * Inform reaper about the reparented
515 * zombie, since wait(2) has something
516 * new to report. Guarantee queueing
517 * of the SIGCHLD signal, similar to
518 * the _exit() behaviour, by providing
519 * our ksiginfo. Ksi is freed by the
522 if (q->p_ksi == NULL) {
525 ksiginfo_copy(q->p_ksi, ksi);
526 ksi->ksi_flags |= KSI_INS;
530 PROC_LOCK(q->p_reaper);
531 pksignal(q->p_reaper, SIGCHLD, ksi1);
532 PROC_UNLOCK(q->p_reaper);
533 } else if (q->p_pdeathsig > 0) {
535 * The child asked to received a signal
538 kern_psignal(q, q->p_pdeathsig);
542 * Traced processes are killed by default
543 * since their existence means someone is
546 t = proc_realparent(q);
548 proc_reparent(q, q->p_reaper, true);
551 proc_reparent(q, t, true);
555 * Since q was found on our children list, the
556 * proc_reparent() call moved q to the orphan
557 * list due to present P_TRACED flag. Clear
558 * orphan link for q now while q is locked.
560 proc_clear_orphan(q);
561 q->p_flag &= ~P_TRACED;
562 q->p_flag2 &= ~P2_PTRACE_FSTP;
565 FOREACH_THREAD_IN_PROC(q, tdt) {
566 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
570 if (kern_kill_on_dbg_exit) {
571 q->p_flag &= ~P_STOPPED_TRACE;
572 kern_psignal(q, SIGKILL);
573 } else if ((q->p_flag & (P_STOPPED_TRACE |
574 P_STOPPED_SIG)) != 0) {
575 sigqueue_delete_proc(q, SIGTRAP);
585 * Also get rid of our orphans.
587 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
589 KASSERT(q->p_oppid == p->p_pid,
590 ("orphan %p of %p has unexpected oppid %d", q, p,
592 q->p_oppid = q->p_reaper->p_pid;
595 * If we are the real parent of this process
596 * but it has been reparented to a debugger, then
597 * check if it asked for a signal when we exit.
599 if (q->p_pdeathsig > 0)
600 kern_psignal(q, q->p_pdeathsig);
601 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
603 proc_clear_orphan(q);
608 if (SDT_PROBES_ENABLED()) {
609 int reason = CLD_EXITED;
610 if (WCOREDUMP(signo))
612 else if (WIFSIGNALED(signo))
614 SDT_PROBE1(proc, , , exit, reason);
618 /* Save exit status. */
622 if (p->p_sysent->sv_ontdexit != NULL)
623 p->p_sysent->sv_ontdexit(td);
627 * Tell the DTrace fasttrap provider about the exit if it
628 * has declared an interest.
630 if (dtrace_fasttrap_exit)
631 dtrace_fasttrap_exit(p);
635 * Notify interested parties of our demise.
637 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
640 * If this is a process with a descriptor, we may not need to deliver
641 * a signal to the parent. proctree_lock is held over
642 * procdesc_exit() to serialize concurrent calls to close() and
646 if (p->p_procdesc == NULL || procdesc_exit(p)) {
648 * Notify parent that we're gone. If parent has the
649 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
650 * notify process 1 instead (and hope it will handle this
653 PROC_LOCK(p->p_pptr);
654 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
655 if (p->p_pptr->p_sigacts->ps_flag &
656 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
659 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
662 proc_reparent(p, p->p_reaper, true);
663 p->p_sigparent = SIGCHLD;
664 PROC_LOCK(p->p_pptr);
667 * Notify parent, so in case he was wait(2)ing or
668 * executing waitpid(2) with our pid, he will
673 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
675 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
677 } else if (p->p_sigparent != 0) {
678 if (p->p_sigparent == SIGCHLD) {
680 } else { /* LINUX thread */
685 PROC_LOCK(p->p_pptr);
686 sx_xunlock(&proctree_lock);
688 if (signal_parent == 1) {
690 } else if (signal_parent == 2) {
691 kern_psignal(p->p_pptr, p->p_sigparent);
694 /* Tell the prison that we are gone. */
695 prison_proc_free(p->p_ucred->cr_prison);
698 * The state PRS_ZOMBIE prevents other proesses from sending
699 * signal to the process, to avoid memory leak, we free memory
700 * for signal queue at the time when the state is set.
702 sigqueue_flush(&p->p_sigqueue);
703 sigqueue_flush(&td->td_sigqueue);
706 * We have to wait until after acquiring all locks before
707 * changing p_state. We need to avoid all possible context
708 * switches (including ones from blocking on a mutex) while
709 * marked as a zombie. We also have to set the zombie state
710 * before we release the parent process' proc lock to avoid
711 * a lost wakeup. So, we first call wakeup, then we grab the
712 * sched lock, update the state, and release the parent process'
716 cv_broadcast(&p->p_pwait);
717 sched_exit(p->p_pptr, td);
719 p->p_state = PRS_ZOMBIE;
720 PROC_UNLOCK(p->p_pptr);
723 * Save our children's rusage information in our exit rusage.
726 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
730 * Make sure the scheduler takes this thread out of its tables etc.
731 * This will also release this thread's reference to the ucred.
732 * Other thread parts to release include pcb bits and such.
737 #ifndef _SYS_SYSPROTO_H_
746 sys_abort2(struct thread *td, struct abort2_args *uap)
748 struct proc *p = td->td_proc;
754 * Do it right now so we can log either proper call of abort2(), or
755 * note, that invalid argument was passed. 512 is big enough to
756 * handle 16 arguments' descriptions with additional comments.
758 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
760 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
761 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
763 * Since we can't return from abort2(), send SIGKILL in cases, where
764 * abort2() was called improperly
767 /* Prevent from DoSes from user-space. */
768 if (uap->nargs < 0 || uap->nargs > 16)
770 if (uap->nargs > 0) {
771 if (uap->args == NULL)
773 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
778 * Limit size of 'reason' string to 128. Will fit even when
779 * maximal number of arguments was chosen to be logged.
781 if (uap->why != NULL) {
782 error = sbuf_copyin(sb, uap->why, 128);
786 sbuf_printf(sb, "(null)");
788 if (uap->nargs > 0) {
789 sbuf_printf(sb, "(");
790 for (i = 0;i < uap->nargs; i++)
791 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
792 sbuf_printf(sb, ")");
795 * Final stage: arguments were proper, string has been
796 * successfully copied from userspace, and copying pointers
797 * from user-space succeed.
801 if (sig == SIGKILL) {
803 sbuf_printf(sb, " (Reason text inaccessible)");
807 log(LOG_INFO, "%s", sbuf_data(sb));
815 * The dirty work is handled by kern_wait().
818 owait(struct thread *td, struct owait_args *uap __unused)
822 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
824 td->td_retval[1] = status;
827 #endif /* COMPAT_43 */
830 * The dirty work is handled by kern_wait().
833 sys_wait4(struct thread *td, struct wait4_args *uap)
835 struct rusage ru, *rup;
838 if (uap->rusage != NULL)
842 error = kern_wait(td, uap->pid, &status, uap->options, rup);
843 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
844 error = copyout(&status, uap->status, sizeof(status));
845 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
846 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
851 sys_wait6(struct thread *td, struct wait6_args *uap)
853 struct __wrusage wru, *wrup;
859 idtype = uap->idtype;
862 if (uap->wrusage != NULL)
867 if (uap->info != NULL) {
869 bzero(sip, sizeof(*sip));
874 * We expect all callers of wait6() to know about WEXITED and
877 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
879 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
880 error = copyout(&status, uap->status, sizeof(status));
881 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
882 error = copyout(&wru, uap->wrusage, sizeof(wru));
883 if (uap->info != NULL && error == 0)
884 error = copyout(&si, uap->info, sizeof(si));
889 * Reap the remains of a zombie process and optionally return status and
890 * rusage. Asserts and will release both the proctree_lock and the process
891 * lock as part of its work.
894 proc_reap(struct thread *td, struct proc *p, int *status, int options)
898 sx_assert(&proctree_lock, SA_XLOCKED);
899 PROC_LOCK_ASSERT(p, MA_OWNED);
900 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
902 mtx_spin_wait_unlocked(&p->p_slock);
907 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
908 if (options & WNOWAIT) {
910 * Only poll, returning the status. Caller does not wish to
911 * release the proc struct just yet.
914 sx_xunlock(&proctree_lock);
919 sigqueue_take(p->p_ksi);
923 * If we got the child via a ptrace 'attach', we need to give it back
926 if (p->p_oppid != p->p_pptr->p_pid) {
928 t = proc_realparent(p);
932 "wait: traced child %d moved back to parent %d", p->p_pid,
934 proc_reparent(p, t, false);
936 pksignal(t, SIGCHLD, p->p_ksi);
938 cv_broadcast(&p->p_pwait);
940 sx_xunlock(&proctree_lock);
946 * Remove other references to this process to ensure we have an
947 * exclusive reference.
949 sx_xlock(PIDHASHLOCK(p->p_pid));
950 LIST_REMOVE(p, p_hash);
951 sx_xunlock(PIDHASHLOCK(p->p_pid));
952 LIST_REMOVE(p, p_sibling);
953 reaper_abandon_children(p, true);
956 proc_clear_orphan(p);
959 if (p->p_procdesc != NULL)
961 sx_xunlock(&proctree_lock);
963 proc_id_clear(PROC_ID_PID, p->p_pid);
966 knlist_detach(p->p_klist);
971 * Removal from allproc list and process group list paired with
972 * PROC_LOCK which was executed during that time should guarantee
973 * nothing can reach this process anymore. As such further locking
976 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
979 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
983 * Decrement the count of procs running with this uid.
985 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
988 * Destroy resource accounting information associated with the process.
993 racct_sub(p, RACCT_NPROC, 1);
1000 * Free credentials, arguments, and sigacts.
1003 pargs_drop(p->p_args);
1005 sigacts_free(p->p_sigacts);
1006 p->p_sigacts = NULL;
1009 * Do any thread-system specific cleanups.
1014 * Give vm and machine-dependent layer a chance to free anything that
1015 * cpu_exit couldn't release while still running in process context.
1019 mac_proc_destroy(p);
1022 KASSERT(FIRST_THREAD_IN_PROC(p),
1023 ("proc_reap: no residual thread!"));
1024 uma_zfree(proc_zone, p);
1025 atomic_add_int(&nprocs, -1);
1029 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1030 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1035 sx_assert(&proctree_lock, SA_XLOCKED);
1041 if (p->p_procdesc == NULL ||
1042 (p->p_pptr == td->td_proc &&
1043 (p->p_flag & P_TRACED) != 0)) {
1050 if (p->p_pid != (pid_t)id) {
1056 if (p->p_pgid != (pid_t)id) {
1062 if (p->p_session->s_sid != (pid_t)id) {
1068 if (p->p_ucred->cr_uid != (uid_t)id) {
1074 if (p->p_ucred->cr_gid != (gid_t)id) {
1080 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1086 * It seems that the thread structures get zeroed out
1087 * at process exit. This makes it impossible to
1088 * support P_SETID, P_CID or P_CPUID.
1095 if (p_canwait(td, p)) {
1100 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1106 * This special case handles a kthread spawned by linux_clone
1107 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1108 * functions need to be able to distinguish between waiting
1109 * on a process and waiting on a thread. It is a thread if
1110 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1111 * signifies we want to wait for threads and not processes.
1113 if ((p->p_sigparent != SIGCHLD) ^
1114 ((options & WLINUXCLONE) != 0)) {
1119 if (siginfo != NULL) {
1120 bzero(siginfo, sizeof(*siginfo));
1121 siginfo->si_errno = 0;
1124 * SUSv4 requires that the si_signo value is always
1125 * SIGCHLD. Obey it despite the rfork(2) interface
1126 * allows to request other signal for child exit
1129 siginfo->si_signo = SIGCHLD;
1132 * This is still a rough estimate. We will fix the
1133 * cases TRAPPED, STOPPED, and CONTINUED later.
1135 if (WCOREDUMP(p->p_xsig)) {
1136 siginfo->si_code = CLD_DUMPED;
1137 siginfo->si_status = WTERMSIG(p->p_xsig);
1138 } else if (WIFSIGNALED(p->p_xsig)) {
1139 siginfo->si_code = CLD_KILLED;
1140 siginfo->si_status = WTERMSIG(p->p_xsig);
1142 siginfo->si_code = CLD_EXITED;
1143 siginfo->si_status = p->p_xexit;
1146 siginfo->si_pid = p->p_pid;
1147 siginfo->si_uid = p->p_ucred->cr_uid;
1150 * The si_addr field would be useful additional
1151 * detail, but apparently the PC value may be lost
1152 * when we reach this point. bzero() above sets
1153 * siginfo->si_addr to NULL.
1158 * There should be no reason to limit resources usage info to
1159 * exited processes only. A snapshot about any resources used
1160 * by a stopped process may be exactly what is needed.
1162 if (wrusage != NULL) {
1163 rup = &wrusage->wru_self;
1166 calcru(p, &rup->ru_utime, &rup->ru_stime);
1169 rup = &wrusage->wru_children;
1170 *rup = p->p_stats->p_cru;
1171 calccru(p, &rup->ru_utime, &rup->ru_stime);
1174 if (p->p_state == PRS_ZOMBIE && !check_only) {
1175 proc_reap(td, p, status, options);
1182 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1183 struct rusage *rusage)
1185 struct __wrusage wru, *wrup;
1191 * Translate the special pid values into the (idtype, pid)
1192 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1193 * kern_wait6() on its own.
1195 if (pid == WAIT_ANY) {
1198 } else if (pid < 0) {
1212 * For backward compatibility we implicitly add flags WEXITED
1213 * and WTRAPPED here.
1215 options |= WEXITED | WTRAPPED;
1216 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1218 *rusage = wru.wru_self;
1223 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1224 int *status, int options, int si_code)
1228 PROC_LOCK_ASSERT(p, MA_OWNED);
1229 sx_assert(&proctree_lock, SA_XLOCKED);
1230 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1231 si_code == CLD_CONTINUED);
1233 cont = si_code == CLD_CONTINUED;
1234 if ((options & WNOWAIT) == 0) {
1236 p->p_flag &= ~P_CONTINUED;
1238 p->p_flag |= P_WAITED;
1239 if (kern_wait_dequeue_sigchld &&
1240 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1241 PROC_LOCK(td->td_proc);
1242 sigqueue_take(p->p_ksi);
1243 PROC_UNLOCK(td->td_proc);
1246 sx_xunlock(&proctree_lock);
1247 if (siginfo != NULL) {
1248 siginfo->si_code = si_code;
1249 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1252 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1254 td->td_retval[0] = p->p_pid;
1258 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1259 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1263 int error, nfound, ret;
1266 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1267 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1268 AUDIT_ARG_VALUE(options);
1272 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1274 id = (id_t)q->p_pgid;
1279 /* If we don't know the option, just return. */
1280 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1281 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1283 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1285 * We will be unable to find any matching processes,
1286 * because there are no known events to look for.
1287 * Prefer to return error instead of blocking
1294 if (q->p_flag & P_STATCHILD) {
1296 q->p_flag &= ~P_STATCHILD;
1299 sx_xlock(&proctree_lock);
1302 LIST_FOREACH(p, &q->p_children, p_sibling) {
1304 ret = proc_to_reap(td, p, idtype, id, status, options,
1305 wrusage, siginfo, 0);
1308 else if (ret != 1) {
1309 td->td_retval[0] = pid;
1314 PROC_LOCK_ASSERT(p, MA_OWNED);
1316 if ((options & WTRAPPED) != 0 &&
1317 (p->p_flag & P_TRACED) != 0) {
1320 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1321 p->p_suspcount == p->p_numthreads &&
1322 (p->p_flag & P_WAITED) == 0);
1326 "wait: returning trapped pid %d status %#x "
1327 "(xstat %d) xthread %d",
1328 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1329 p->p_xthread != NULL ?
1330 p->p_xthread->td_tid : -1);
1331 report_alive_proc(td, p, siginfo, status,
1332 options, CLD_TRAPPED);
1336 if ((options & WUNTRACED) != 0 &&
1337 (p->p_flag & P_STOPPED_SIG) != 0) {
1339 report = (p->p_suspcount == p->p_numthreads &&
1340 ((p->p_flag & P_WAITED) == 0));
1343 report_alive_proc(td, p, siginfo, status,
1344 options, CLD_STOPPED);
1348 if ((options & WCONTINUED) != 0 &&
1349 (p->p_flag & P_CONTINUED) != 0) {
1350 report_alive_proc(td, p, siginfo, status, options,
1358 * Look in the orphans list too, to allow the parent to
1359 * collect it's child exit status even if child is being
1362 * Debugger detaches from the parent upon successful
1363 * switch-over from parent to child. At this point due to
1364 * re-parenting the parent loses the child to debugger and a
1365 * wait4(2) call would report that it has no children to wait
1366 * for. By maintaining a list of orphans we allow the parent
1367 * to successfully wait until the child becomes a zombie.
1370 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1371 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1374 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1375 (int)td->td_retval[0]));
1383 sx_xunlock(&proctree_lock);
1386 if (options & WNOHANG) {
1387 sx_xunlock(&proctree_lock);
1388 td->td_retval[0] = 0;
1392 if (q->p_flag & P_STATCHILD) {
1393 q->p_flag &= ~P_STATCHILD;
1397 sx_xunlock(&proctree_lock);
1398 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1405 proc_add_orphan(struct proc *child, struct proc *parent)
1408 sx_assert(&proctree_lock, SX_XLOCKED);
1409 KASSERT((child->p_flag & P_TRACED) != 0,
1410 ("proc_add_orphan: not traced"));
1412 if (LIST_EMPTY(&parent->p_orphans)) {
1413 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1414 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1416 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1419 child->p_treeflag |= P_TREE_ORPHANED;
1423 * Make process 'parent' the new parent of process 'child'.
1424 * Must be called with an exclusive hold of proctree lock.
1427 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1430 sx_assert(&proctree_lock, SX_XLOCKED);
1431 PROC_LOCK_ASSERT(child, MA_OWNED);
1432 if (child->p_pptr == parent)
1435 PROC_LOCK(child->p_pptr);
1436 sigqueue_take(child->p_ksi);
1437 PROC_UNLOCK(child->p_pptr);
1438 LIST_REMOVE(child, p_sibling);
1439 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1441 proc_clear_orphan(child);
1442 if ((child->p_flag & P_TRACED) != 0) {
1443 proc_add_orphan(child, child->p_pptr);
1446 child->p_pptr = parent;
1448 child->p_oppid = parent->p_pid;