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
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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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33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/capsicum.h>
49 #include <sys/eventhandler.h>
50 #include <sys/kernel.h>
52 #include <sys/malloc.h>
54 #include <sys/mutex.h>
56 #include <sys/procdesc.h>
60 #include <sys/vmmeter.h>
61 #include <sys/vnode.h>
62 #include <sys/racct.h>
63 #include <sys/resourcevar.h>
65 #include <sys/signalvar.h>
66 #include <sys/sched.h>
68 #include <sys/syscallsubr.h>
69 #include <sys/sysctl.h>
70 #include <sys/syslog.h>
71 #include <sys/ptrace.h>
72 #include <sys/acct.h> /* for acct_process() function prototype */
73 #include <sys/filedesc.h>
77 #include <sys/sysent.h>
78 #include <sys/timers.h>
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_LOCKED);
140 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
141 if ((p->p_treeflag & P_TREE_REAPER) == 0)
144 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
145 LIST_REMOVE(p2, p_reapsibling);
147 p2->p_reapsubtree = p->p_reapsubtree;
148 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
149 if (exiting && p2->p_pptr == p) {
151 proc_reparent(p2, p1, true);
155 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
156 p->p_treeflag &= ~P_TREE_REAPER;
160 reaper_clear(struct proc *p)
165 sx_assert(&proctree_lock, SX_LOCKED);
166 LIST_REMOVE(p, p_reapsibling);
167 if (p->p_reapsubtree == 1)
170 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) {
171 if (p1->p_reapsubtree == p->p_reapsubtree) {
177 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree);
181 proc_clear_orphan(struct proc *p)
185 sx_assert(&proctree_lock, SA_XLOCKED);
186 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
188 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
189 p1 = LIST_NEXT(p, p_orphan);
191 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
192 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
194 LIST_REMOVE(p, p_orphan);
195 p->p_treeflag &= ~P_TREE_ORPHANED;
199 exit_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_exit(struct thread *td, struct exit_args *uap)
212 exit1(td, uap->rval, 0);
217 * Exit: deallocate address space and other resources, change proc state to
218 * zombie, and unlink proc from allproc and parent's lists. Save exit status
219 * and rusage for wait(). Check for child processes and orphan them.
222 exit1(struct thread *td, int rval, int signo)
224 struct proc *p, *nq, *q, *t;
226 ksiginfo_t *ksi, *ksi1;
229 mtx_assert(&Giant, MA_NOTOWNED);
230 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
231 TSPROCEXIT(td->td_proc->p_pid);
235 * XXX in case we're rebooting we just let init die in order to
236 * work around an unsolved stack overflow seen very late during
237 * shutdown on sparc64 when the gmirror worker process exists.
238 * XXX what to do now that sparc64 is gone... remove if?
240 if (p == initproc && rebooting == 0) {
241 printf("init died (signal %d, exit %d)\n", signo, rval);
242 panic("Going nowhere without my init!");
246 * Deref SU mp, since the thread does not return to userspace.
248 td_softdep_cleanup(td);
251 * MUST abort all other threads before proceeding past here.
255 * First check if some other thread or external request got
256 * here before us. If so, act appropriately: exit or suspend.
257 * We must ensure that stop requests are handled before we set
260 thread_suspend_check(0);
261 while (p->p_flag & P_HADTHREADS) {
263 * Kill off the other threads. This requires
264 * some co-operation from other parts of the kernel
265 * so it may not be instantaneous. With this state set
266 * any thread entering the kernel from userspace will
267 * thread_exit() in trap(). Any thread attempting to
268 * sleep will return immediately with EINTR or EWOULDBLOCK
269 * which will hopefully force them to back out to userland
270 * freeing resources as they go. Any thread attempting
271 * to return to userland will thread_exit() from userret().
272 * thread_exit() will unsuspend us when the last of the
273 * other threads exits.
274 * If there is already a thread singler after resumption,
275 * calling thread_single will fail; in that case, we just
276 * re-check all suspension request, the thread should
277 * either be suspended there or exit.
279 if (!thread_single(p, SINGLE_EXIT))
281 * All other activity in this process is now
282 * stopped. Threading support has been turned
287 * Recheck for new stop or suspend requests which
288 * might appear while process lock was dropped in
291 thread_suspend_check(0);
293 KASSERT(p->p_numthreads == 1,
294 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
295 racct_sub(p, RACCT_NTHR, 1);
297 /* Let event handler change exit status */
302 * Ignore any pending request to stop due to a stop signal.
303 * Once P_WEXIT is set, future requests will be ignored as
306 p->p_flag &= ~P_STOPPED_SIG;
307 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
309 /* Note that we are exiting. */
310 p->p_flag |= P_WEXIT;
313 * Wait for any processes that have a hold on our vmspace to
314 * release their reference.
316 while (p->p_lock > 0)
317 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
320 /* Drain the limit callout while we don't have the proc locked */
321 callout_drain(&p->p_limco);
325 * The Sun BSM exit token contains two components: an exit status as
326 * passed to exit(), and a return value to indicate what sort of exit
327 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
328 * what the return value is.
330 AUDIT_ARG_EXIT(rval, 0);
331 AUDIT_SYSCALL_EXIT(0, td);
334 /* Are we a task leader with peers? */
335 if (p->p_peers != NULL && p == p->p_leader) {
336 mtx_lock(&ppeers_lock);
340 kern_psignal(q, SIGKILL);
344 while (p->p_peers != NULL)
345 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
346 mtx_unlock(&ppeers_lock);
352 * Check if any loadable modules need anything done at process exit.
353 * E.g. SYSV IPC stuff.
354 * Event handler could change exit status.
355 * XXX what if one of these generates an error?
357 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
360 * If parent is waiting for us to exit or exec,
361 * P_PPWAIT is set; we will wakeup the parent below.
368 * Stop the real interval timer. If the handler is currently
369 * executing, prevent it from rearming itself and let it finish.
371 if (timevalisset(&p->p_realtimer.it_value) &&
372 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
373 timevalclear(&p->p_realtimer.it_interval);
374 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
375 KASSERT(!timevalisset(&p->p_realtimer.it_value),
376 ("realtime timer is still armed"));
381 if (p->p_sysent->sv_onexit != NULL)
382 p->p_sysent->sv_onexit(p);
386 * Reset any sigio structures pointing to us as a result of
387 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
389 funsetownlst(&p->p_sigiolst);
392 * Close open files and release open-file table.
399 * If this thread tickled GEOM, we need to wait for the giggling to
400 * stop before we return to userland
402 if (td->td_pflags & TDP_GEOM)
406 * Remove ourself from our leader's peer list and wake our leader.
408 if (p->p_leader->p_peers != NULL) {
409 mtx_lock(&ppeers_lock);
410 if (p->p_leader->p_peers != NULL) {
412 while (q->p_peers != p)
414 q->p_peers = p->p_peers;
417 mtx_unlock(&ppeers_lock);
420 exec_free_abi_mappings(p);
422 (void)acct_process(td);
428 * Release reference to text vnode etc
430 if (p->p_textvp != NULL) {
434 if (p->p_textdvp != NULL) {
438 if (p->p_binname != NULL) {
439 free(p->p_binname, M_PARGS);
444 * Release our limits structure.
446 lim_free(p->p_limit);
452 * Call machine-dependent code to release any
453 * machine-dependent resources other than the address space.
454 * The address space is released by "vmspace_exitfree(p)" in
459 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
462 * Remove from allproc. It still sits in the hash.
464 sx_xlock(&allproc_lock);
465 LIST_REMOVE(p, p_list);
469 * Used by ddb's 'ps' command to find this process via the
472 p->p_list.le_prev = NULL;
474 sx_xunlock(&allproc_lock);
476 sx_xlock(&proctree_lock);
478 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
482 * killjobc() might drop and re-acquire proctree_lock to
483 * revoke control tty if exiting process was a session leader.
488 * Reparent all children processes:
489 * - traced ones to the original parent (or init if we are that parent)
492 q = LIST_FIRST(&p->p_children);
493 if (q != NULL) /* only need this if any child is S_ZOMB */
495 for (; q != NULL; q = nq) {
496 nq = LIST_NEXT(q, p_sibling);
497 ksi = ksiginfo_alloc(TRUE);
499 q->p_sigparent = SIGCHLD;
501 if ((q->p_flag & P_TRACED) == 0) {
502 proc_reparent(q, q->p_reaper, true);
503 if (q->p_state == PRS_ZOMBIE) {
505 * Inform reaper about the reparented
506 * zombie, since wait(2) has something
507 * new to report. Guarantee queueing
508 * of the SIGCHLD signal, similar to
509 * the _exit() behaviour, by providing
510 * our ksiginfo. Ksi is freed by the
513 if (q->p_ksi == NULL) {
516 ksiginfo_copy(q->p_ksi, ksi);
517 ksi->ksi_flags |= KSI_INS;
521 PROC_LOCK(q->p_reaper);
522 pksignal(q->p_reaper, SIGCHLD, ksi1);
523 PROC_UNLOCK(q->p_reaper);
524 } else if (q->p_pdeathsig > 0) {
526 * The child asked to received a signal
529 kern_psignal(q, q->p_pdeathsig);
533 * Traced processes are killed by default
534 * since their existence means someone is
537 t = proc_realparent(q);
539 proc_reparent(q, q->p_reaper, true);
542 proc_reparent(q, t, true);
546 * Since q was found on our children list, the
547 * proc_reparent() call moved q to the orphan
548 * list due to present P_TRACED flag. Clear
549 * orphan link for q now while q is locked.
551 proc_clear_orphan(q);
552 q->p_flag &= ~P_TRACED;
553 q->p_flag2 &= ~P2_PTRACE_FSTP;
556 FOREACH_THREAD_IN_PROC(q, tdt) {
557 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
561 if (kern_kill_on_dbg_exit) {
562 q->p_flag &= ~P_STOPPED_TRACE;
563 kern_psignal(q, SIGKILL);
564 } else if ((q->p_flag & (P_STOPPED_TRACE |
565 P_STOPPED_SIG)) != 0) {
566 sigqueue_delete_proc(q, SIGTRAP);
576 * Also get rid of our orphans.
578 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
580 KASSERT(q->p_oppid == p->p_pid,
581 ("orphan %p of %p has unexpected oppid %d", q, p,
583 q->p_oppid = q->p_reaper->p_pid;
586 * If we are the real parent of this process
587 * but it has been reparented to a debugger, then
588 * check if it asked for a signal when we exit.
590 if (q->p_pdeathsig > 0)
591 kern_psignal(q, q->p_pdeathsig);
592 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
594 proc_clear_orphan(q);
599 if (SDT_PROBES_ENABLED()) {
600 int reason = CLD_EXITED;
601 if (WCOREDUMP(signo))
603 else if (WIFSIGNALED(signo))
605 SDT_PROBE1(proc, , , exit, reason);
609 /* Save exit status. */
613 if (p->p_sysent->sv_ontdexit != NULL)
614 p->p_sysent->sv_ontdexit(td);
618 * Tell the DTrace fasttrap provider about the exit if it
619 * has declared an interest.
621 if (dtrace_fasttrap_exit)
622 dtrace_fasttrap_exit(p);
626 * Notify interested parties of our demise.
628 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
631 * If this is a process with a descriptor, we may not need to deliver
632 * a signal to the parent. proctree_lock is held over
633 * procdesc_exit() to serialize concurrent calls to close() and
637 if (p->p_procdesc == NULL || procdesc_exit(p)) {
639 * Notify parent that we're gone. If parent has the
640 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
641 * notify process 1 instead (and hope it will handle this
644 PROC_LOCK(p->p_pptr);
645 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
646 if (p->p_pptr->p_sigacts->ps_flag &
647 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
650 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
653 proc_reparent(p, p->p_reaper, true);
654 p->p_sigparent = SIGCHLD;
655 PROC_LOCK(p->p_pptr);
658 * Notify parent, so in case he was wait(2)ing or
659 * executing waitpid(2) with our pid, he will
664 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
666 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
668 } else if (p->p_sigparent != 0) {
669 if (p->p_sigparent == SIGCHLD) {
671 } else { /* LINUX thread */
676 PROC_LOCK(p->p_pptr);
677 sx_xunlock(&proctree_lock);
679 if (signal_parent == 1) {
681 } else if (signal_parent == 2) {
682 kern_psignal(p->p_pptr, p->p_sigparent);
685 /* Tell the prison that we are gone. */
686 prison_proc_free(p->p_ucred->cr_prison);
689 * The state PRS_ZOMBIE prevents other proesses from sending
690 * signal to the process, to avoid memory leak, we free memory
691 * for signal queue at the time when the state is set.
693 sigqueue_flush(&p->p_sigqueue);
694 sigqueue_flush(&td->td_sigqueue);
697 * We have to wait until after acquiring all locks before
698 * changing p_state. We need to avoid all possible context
699 * switches (including ones from blocking on a mutex) while
700 * marked as a zombie. We also have to set the zombie state
701 * before we release the parent process' proc lock to avoid
702 * a lost wakeup. So, we first call wakeup, then we grab the
703 * sched lock, update the state, and release the parent process'
707 cv_broadcast(&p->p_pwait);
708 sched_exit(p->p_pptr, td);
710 p->p_state = PRS_ZOMBIE;
711 PROC_UNLOCK(p->p_pptr);
714 * Save our children's rusage information in our exit rusage.
717 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
721 * Make sure the scheduler takes this thread out of its tables etc.
722 * This will also release this thread's reference to the ucred.
723 * Other thread parts to release include pcb bits and such.
728 #ifndef _SYS_SYSPROTO_H_
737 sys_abort2(struct thread *td, struct abort2_args *uap)
744 if (nargs < 0 || nargs > nitems(uargs))
748 if (uap->args != NULL) {
749 error = copyin(uap->args, uargs,
750 nargs * sizeof(void *));
758 return (kern_abort2(td, uap->why, nargs, uargsp));
764 * why - user pointer to why
765 * nargs - number of arguments copied or -1 if an error occured in copying
766 * args - pointer to an array of pointers in kernel format
769 kern_abort2(struct thread *td, const char *why, int nargs, void **uargs)
771 struct proc *p = td->td_proc;
776 * Do it right now so we can log either proper call of abort2(), or
777 * note, that invalid argument was passed. 512 is big enough to
778 * handle 16 arguments' descriptions with additional comments.
780 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
782 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
783 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
785 * Since we can't return from abort2(), send SIGKILL in cases, where
786 * abort2() was called improperly
789 /* Prevent from DoSes from user-space. */
792 KASSERT(nargs >= 0 && nargs <= 16, ("called with too many args (%d)",
795 * Limit size of 'reason' string to 128. Will fit even when
796 * maximal number of arguments was chosen to be logged.
799 error = sbuf_copyin(sb, why, 128);
803 sbuf_printf(sb, "(null)");
806 sbuf_printf(sb, "(");
807 for (i = 0;i < nargs; i++)
808 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
809 sbuf_printf(sb, ")");
812 * Final stage: arguments were proper, string has been
813 * successfully copied from userspace, and copying pointers
814 * from user-space succeed.
818 if (sig == SIGKILL) {
820 sbuf_printf(sb, " (Reason text inaccessible)");
824 log(LOG_INFO, "%s", sbuf_data(sb));
832 * The dirty work is handled by kern_wait().
835 owait(struct thread *td, struct owait_args *uap __unused)
839 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
841 td->td_retval[1] = status;
844 #endif /* COMPAT_43 */
847 * The dirty work is handled by kern_wait().
850 sys_wait4(struct thread *td, struct wait4_args *uap)
852 struct rusage ru, *rup;
855 if (uap->rusage != NULL)
859 error = kern_wait(td, uap->pid, &status, uap->options, rup);
860 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
861 error = copyout(&status, uap->status, sizeof(status));
862 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
863 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
868 sys_wait6(struct thread *td, struct wait6_args *uap)
870 struct __wrusage wru, *wrup;
876 idtype = uap->idtype;
879 if (uap->wrusage != NULL)
884 if (uap->info != NULL) {
886 bzero(sip, sizeof(*sip));
891 * We expect all callers of wait6() to know about WEXITED and
894 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
896 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
897 error = copyout(&status, uap->status, sizeof(status));
898 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
899 error = copyout(&wru, uap->wrusage, sizeof(wru));
900 if (uap->info != NULL && error == 0)
901 error = copyout(&si, uap->info, sizeof(si));
906 * Reap the remains of a zombie process and optionally return status and
907 * rusage. Asserts and will release both the proctree_lock and the process
908 * lock as part of its work.
911 proc_reap(struct thread *td, struct proc *p, int *status, int options)
915 sx_assert(&proctree_lock, SA_XLOCKED);
916 PROC_LOCK_ASSERT(p, MA_OWNED);
917 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
919 mtx_spin_wait_unlocked(&p->p_slock);
924 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
925 if (options & WNOWAIT) {
927 * Only poll, returning the status. Caller does not wish to
928 * release the proc struct just yet.
931 sx_xunlock(&proctree_lock);
936 sigqueue_take(p->p_ksi);
940 * If we got the child via a ptrace 'attach', we need to give it back
943 if (p->p_oppid != p->p_pptr->p_pid) {
945 t = proc_realparent(p);
949 "wait: traced child %d moved back to parent %d", p->p_pid,
951 proc_reparent(p, t, false);
953 pksignal(t, SIGCHLD, p->p_ksi);
955 cv_broadcast(&p->p_pwait);
957 sx_xunlock(&proctree_lock);
963 * Remove other references to this process to ensure we have an
964 * exclusive reference.
966 sx_xlock(PIDHASHLOCK(p->p_pid));
967 LIST_REMOVE(p, p_hash);
968 sx_xunlock(PIDHASHLOCK(p->p_pid));
969 LIST_REMOVE(p, p_sibling);
970 reaper_abandon_children(p, true);
973 proc_clear_orphan(p);
976 if (p->p_procdesc != NULL)
978 sx_xunlock(&proctree_lock);
980 proc_id_clear(PROC_ID_PID, p->p_pid);
983 knlist_detach(p->p_klist);
988 * Removal from allproc list and process group list paired with
989 * PROC_LOCK which was executed during that time should guarantee
990 * nothing can reach this process anymore. As such further locking
993 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
996 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
1000 * Decrement the count of procs running with this uid.
1002 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
1005 * Destroy resource accounting information associated with the process.
1010 racct_sub(p, RACCT_NPROC, 1);
1017 * Free credentials, arguments, and sigacts.
1020 pargs_drop(p->p_args);
1022 sigacts_free(p->p_sigacts);
1023 p->p_sigacts = NULL;
1026 * Do any thread-system specific cleanups.
1031 * Give vm and machine-dependent layer a chance to free anything that
1032 * cpu_exit couldn't release while still running in process context.
1036 mac_proc_destroy(p);
1039 KASSERT(FIRST_THREAD_IN_PROC(p),
1040 ("proc_reap: no residual thread!"));
1041 uma_zfree(proc_zone, p);
1042 atomic_add_int(&nprocs, -1);
1046 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1047 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1052 sx_assert(&proctree_lock, SA_XLOCKED);
1058 if (p->p_procdesc == NULL ||
1059 (p->p_pptr == td->td_proc &&
1060 (p->p_flag & P_TRACED) != 0)) {
1067 if (p->p_pid != (pid_t)id) {
1073 if (p->p_pgid != (pid_t)id) {
1079 if (p->p_session->s_sid != (pid_t)id) {
1085 if (p->p_ucred->cr_uid != (uid_t)id) {
1091 if (p->p_ucred->cr_gid != (gid_t)id) {
1097 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1103 * It seems that the thread structures get zeroed out
1104 * at process exit. This makes it impossible to
1105 * support P_SETID, P_CID or P_CPUID.
1112 if (p_canwait(td, p)) {
1117 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1123 * This special case handles a kthread spawned by linux_clone
1124 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1125 * functions need to be able to distinguish between waiting
1126 * on a process and waiting on a thread. It is a thread if
1127 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1128 * signifies we want to wait for threads and not processes.
1130 if ((p->p_sigparent != SIGCHLD) ^
1131 ((options & WLINUXCLONE) != 0)) {
1136 if (siginfo != NULL) {
1137 bzero(siginfo, sizeof(*siginfo));
1138 siginfo->si_errno = 0;
1141 * SUSv4 requires that the si_signo value is always
1142 * SIGCHLD. Obey it despite the rfork(2) interface
1143 * allows to request other signal for child exit
1146 siginfo->si_signo = SIGCHLD;
1149 * This is still a rough estimate. We will fix the
1150 * cases TRAPPED, STOPPED, and CONTINUED later.
1152 if (WCOREDUMP(p->p_xsig)) {
1153 siginfo->si_code = CLD_DUMPED;
1154 siginfo->si_status = WTERMSIG(p->p_xsig);
1155 } else if (WIFSIGNALED(p->p_xsig)) {
1156 siginfo->si_code = CLD_KILLED;
1157 siginfo->si_status = WTERMSIG(p->p_xsig);
1159 siginfo->si_code = CLD_EXITED;
1160 siginfo->si_status = p->p_xexit;
1163 siginfo->si_pid = p->p_pid;
1164 siginfo->si_uid = p->p_ucred->cr_uid;
1167 * The si_addr field would be useful additional
1168 * detail, but apparently the PC value may be lost
1169 * when we reach this point. bzero() above sets
1170 * siginfo->si_addr to NULL.
1175 * There should be no reason to limit resources usage info to
1176 * exited processes only. A snapshot about any resources used
1177 * by a stopped process may be exactly what is needed.
1179 if (wrusage != NULL) {
1180 rup = &wrusage->wru_self;
1183 calcru(p, &rup->ru_utime, &rup->ru_stime);
1186 rup = &wrusage->wru_children;
1187 *rup = p->p_stats->p_cru;
1188 calccru(p, &rup->ru_utime, &rup->ru_stime);
1191 if (p->p_state == PRS_ZOMBIE && !check_only) {
1192 proc_reap(td, p, status, options);
1199 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1200 struct rusage *rusage)
1202 struct __wrusage wru, *wrup;
1208 * Translate the special pid values into the (idtype, pid)
1209 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1210 * kern_wait6() on its own.
1212 if (pid == WAIT_ANY) {
1215 } else if (pid < 0) {
1229 * For backward compatibility we implicitly add flags WEXITED
1230 * and WTRAPPED here.
1232 options |= WEXITED | WTRAPPED;
1233 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1235 *rusage = wru.wru_self;
1240 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1241 int *status, int options, int si_code)
1245 PROC_LOCK_ASSERT(p, MA_OWNED);
1246 sx_assert(&proctree_lock, SA_XLOCKED);
1247 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1248 si_code == CLD_CONTINUED);
1250 cont = si_code == CLD_CONTINUED;
1251 if ((options & WNOWAIT) == 0) {
1253 p->p_flag &= ~P_CONTINUED;
1255 p->p_flag |= P_WAITED;
1256 if (kern_wait_dequeue_sigchld &&
1257 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1258 PROC_LOCK(td->td_proc);
1259 sigqueue_take(p->p_ksi);
1260 PROC_UNLOCK(td->td_proc);
1263 sx_xunlock(&proctree_lock);
1264 if (siginfo != NULL) {
1265 siginfo->si_code = si_code;
1266 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1269 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1271 td->td_retval[0] = p->p_pid;
1275 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1276 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1280 int error, nfound, ret;
1283 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1284 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1285 AUDIT_ARG_VALUE(options);
1289 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1291 id = (id_t)q->p_pgid;
1296 /* If we don't know the option, just return. */
1297 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1298 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1300 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1302 * We will be unable to find any matching processes,
1303 * because there are no known events to look for.
1304 * Prefer to return error instead of blocking
1311 if (q->p_flag & P_STATCHILD) {
1313 q->p_flag &= ~P_STATCHILD;
1316 sx_xlock(&proctree_lock);
1319 LIST_FOREACH(p, &q->p_children, p_sibling) {
1321 ret = proc_to_reap(td, p, idtype, id, status, options,
1322 wrusage, siginfo, 0);
1325 else if (ret != 1) {
1326 td->td_retval[0] = pid;
1331 PROC_LOCK_ASSERT(p, MA_OWNED);
1333 if ((options & WTRAPPED) != 0 &&
1334 (p->p_flag & P_TRACED) != 0) {
1337 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1338 p->p_suspcount == p->p_numthreads &&
1339 (p->p_flag & P_WAITED) == 0);
1343 "wait: returning trapped pid %d status %#x "
1344 "(xstat %d) xthread %d",
1345 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1346 p->p_xthread != NULL ?
1347 p->p_xthread->td_tid : -1);
1348 report_alive_proc(td, p, siginfo, status,
1349 options, CLD_TRAPPED);
1353 if ((options & WUNTRACED) != 0 &&
1354 (p->p_flag & P_STOPPED_SIG) != 0) {
1356 report = (p->p_suspcount == p->p_numthreads &&
1357 ((p->p_flag & P_WAITED) == 0));
1360 report_alive_proc(td, p, siginfo, status,
1361 options, CLD_STOPPED);
1365 if ((options & WCONTINUED) != 0 &&
1366 (p->p_flag & P_CONTINUED) != 0) {
1367 report_alive_proc(td, p, siginfo, status, options,
1375 * Look in the orphans list too, to allow the parent to
1376 * collect it's child exit status even if child is being
1379 * Debugger detaches from the parent upon successful
1380 * switch-over from parent to child. At this point due to
1381 * re-parenting the parent loses the child to debugger and a
1382 * wait4(2) call would report that it has no children to wait
1383 * for. By maintaining a list of orphans we allow the parent
1384 * to successfully wait until the child becomes a zombie.
1387 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1388 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1391 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1392 (int)td->td_retval[0]));
1400 sx_xunlock(&proctree_lock);
1403 if (options & WNOHANG) {
1404 sx_xunlock(&proctree_lock);
1405 td->td_retval[0] = 0;
1409 if (q->p_flag & P_STATCHILD) {
1410 q->p_flag &= ~P_STATCHILD;
1414 sx_xunlock(&proctree_lock);
1415 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1422 proc_add_orphan(struct proc *child, struct proc *parent)
1425 sx_assert(&proctree_lock, SX_XLOCKED);
1426 KASSERT((child->p_flag & P_TRACED) != 0,
1427 ("proc_add_orphan: not traced"));
1429 if (LIST_EMPTY(&parent->p_orphans)) {
1430 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1431 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1433 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1436 child->p_treeflag |= P_TREE_ORPHANED;
1440 * Make process 'parent' the new parent of process 'child'.
1441 * Must be called with an exclusive hold of proctree lock.
1444 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1447 sx_assert(&proctree_lock, SX_XLOCKED);
1448 PROC_LOCK_ASSERT(child, MA_OWNED);
1449 if (child->p_pptr == parent)
1452 PROC_LOCK(child->p_pptr);
1453 sigqueue_take(child->p_ksi);
1454 PROC_UNLOCK(child->p_pptr);
1455 LIST_REMOVE(child, p_sibling);
1456 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1458 proc_clear_orphan(child);
1459 if ((child->p_flag & P_TRACED) != 0) {
1460 proc_add_orphan(child, child->p_pptr);
1463 child->p_pptr = parent;
1465 child->p_oppid = parent->p_pid;