2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
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9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
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13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
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20 * 3. Neither the name of the University nor the names of its contributors
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24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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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_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(&p->p_itcallout) == 0) {
373 timevalclear(&p->p_realtimer.it_interval);
375 callout_drain(&p->p_itcallout);
380 if (p->p_sysent->sv_onexit != NULL)
381 p->p_sysent->sv_onexit(p);
385 * Reset any sigio structures pointing to us as a result of
386 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
388 funsetownlst(&p->p_sigiolst);
391 * Close open files and release open-file table.
398 * If this thread tickled GEOM, we need to wait for the giggling to
399 * stop before we return to userland
401 if (td->td_pflags & TDP_GEOM)
405 * Remove ourself from our leader's peer list and wake our leader.
407 if (p->p_leader->p_peers != NULL) {
408 mtx_lock(&ppeers_lock);
409 if (p->p_leader->p_peers != NULL) {
411 while (q->p_peers != p)
413 q->p_peers = p->p_peers;
416 mtx_unlock(&ppeers_lock);
419 exec_free_abi_mappings(p);
421 (void)acct_process(td);
427 * Release reference to text vnode etc
429 if (p->p_textvp != NULL) {
433 if (p->p_textdvp != NULL) {
437 if (p->p_binname != NULL) {
438 free(p->p_binname, M_PARGS);
443 * Release our limits structure.
445 lim_free(p->p_limit);
451 * Call machine-dependent code to release any
452 * machine-dependent resources other than the address space.
453 * The address space is released by "vmspace_exitfree(p)" in
458 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
461 * Remove from allproc. It still sits in the hash.
463 sx_xlock(&allproc_lock);
464 LIST_REMOVE(p, p_list);
468 * Used by ddb's 'ps' command to find this process via the
471 p->p_list.le_prev = NULL;
473 sx_xunlock(&allproc_lock);
475 sx_xlock(&proctree_lock);
477 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
481 * killjobc() might drop and re-acquire proctree_lock to
482 * revoke control tty if exiting process was a session leader.
487 * Reparent all children processes:
488 * - traced ones to the original parent (or init if we are that parent)
491 q = LIST_FIRST(&p->p_children);
492 if (q != NULL) /* only need this if any child is S_ZOMB */
494 for (; q != NULL; q = nq) {
495 nq = LIST_NEXT(q, p_sibling);
496 ksi = ksiginfo_alloc(TRUE);
498 q->p_sigparent = SIGCHLD;
500 if ((q->p_flag & P_TRACED) == 0) {
501 proc_reparent(q, q->p_reaper, true);
502 if (q->p_state == PRS_ZOMBIE) {
504 * Inform reaper about the reparented
505 * zombie, since wait(2) has something
506 * new to report. Guarantee queueing
507 * of the SIGCHLD signal, similar to
508 * the _exit() behaviour, by providing
509 * our ksiginfo. Ksi is freed by the
512 if (q->p_ksi == NULL) {
515 ksiginfo_copy(q->p_ksi, ksi);
516 ksi->ksi_flags |= KSI_INS;
520 PROC_LOCK(q->p_reaper);
521 pksignal(q->p_reaper, SIGCHLD, ksi1);
522 PROC_UNLOCK(q->p_reaper);
523 } else if (q->p_pdeathsig > 0) {
525 * The child asked to received a signal
528 kern_psignal(q, q->p_pdeathsig);
532 * Traced processes are killed by default
533 * since their existence means someone is
536 t = proc_realparent(q);
538 proc_reparent(q, q->p_reaper, true);
541 proc_reparent(q, t, true);
545 * Since q was found on our children list, the
546 * proc_reparent() call moved q to the orphan
547 * list due to present P_TRACED flag. Clear
548 * orphan link for q now while q is locked.
550 proc_clear_orphan(q);
551 q->p_flag &= ~P_TRACED;
552 q->p_flag2 &= ~P2_PTRACE_FSTP;
555 FOREACH_THREAD_IN_PROC(q, tdt) {
556 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
560 if (kern_kill_on_dbg_exit) {
561 q->p_flag &= ~P_STOPPED_TRACE;
562 kern_psignal(q, SIGKILL);
563 } else if ((q->p_flag & (P_STOPPED_TRACE |
564 P_STOPPED_SIG)) != 0) {
565 sigqueue_delete_proc(q, SIGTRAP);
575 * Also get rid of our orphans.
577 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
579 KASSERT(q->p_oppid == p->p_pid,
580 ("orphan %p of %p has unexpected oppid %d", q, p,
582 q->p_oppid = q->p_reaper->p_pid;
585 * If we are the real parent of this process
586 * but it has been reparented to a debugger, then
587 * check if it asked for a signal when we exit.
589 if (q->p_pdeathsig > 0)
590 kern_psignal(q, q->p_pdeathsig);
591 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
593 proc_clear_orphan(q);
598 if (SDT_PROBES_ENABLED()) {
599 int reason = CLD_EXITED;
600 if (WCOREDUMP(signo))
602 else if (WIFSIGNALED(signo))
604 SDT_PROBE1(proc, , , exit, reason);
608 /* Save exit status. */
612 if (p->p_sysent->sv_ontdexit != NULL)
613 p->p_sysent->sv_ontdexit(td);
617 * Tell the DTrace fasttrap provider about the exit if it
618 * has declared an interest.
620 if (dtrace_fasttrap_exit)
621 dtrace_fasttrap_exit(p);
625 * Notify interested parties of our demise.
627 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
630 * If this is a process with a descriptor, we may not need to deliver
631 * a signal to the parent. proctree_lock is held over
632 * procdesc_exit() to serialize concurrent calls to close() and
636 if (p->p_procdesc == NULL || procdesc_exit(p)) {
638 * Notify parent that we're gone. If parent has the
639 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
640 * notify process 1 instead (and hope it will handle this
643 PROC_LOCK(p->p_pptr);
644 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
645 if (p->p_pptr->p_sigacts->ps_flag &
646 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
649 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
652 proc_reparent(p, p->p_reaper, true);
653 p->p_sigparent = SIGCHLD;
654 PROC_LOCK(p->p_pptr);
657 * Notify parent, so in case he was wait(2)ing or
658 * executing waitpid(2) with our pid, he will
663 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
665 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
667 } else if (p->p_sigparent != 0) {
668 if (p->p_sigparent == SIGCHLD) {
670 } else { /* LINUX thread */
675 PROC_LOCK(p->p_pptr);
676 sx_xunlock(&proctree_lock);
678 if (signal_parent == 1) {
680 } else if (signal_parent == 2) {
681 kern_psignal(p->p_pptr, p->p_sigparent);
684 /* Tell the prison that we are gone. */
685 prison_proc_free(p->p_ucred->cr_prison);
688 * The state PRS_ZOMBIE prevents other proesses from sending
689 * signal to the process, to avoid memory leak, we free memory
690 * for signal queue at the time when the state is set.
692 sigqueue_flush(&p->p_sigqueue);
693 sigqueue_flush(&td->td_sigqueue);
696 * We have to wait until after acquiring all locks before
697 * changing p_state. We need to avoid all possible context
698 * switches (including ones from blocking on a mutex) while
699 * marked as a zombie. We also have to set the zombie state
700 * before we release the parent process' proc lock to avoid
701 * a lost wakeup. So, we first call wakeup, then we grab the
702 * sched lock, update the state, and release the parent process'
706 cv_broadcast(&p->p_pwait);
707 sched_exit(p->p_pptr, td);
709 p->p_state = PRS_ZOMBIE;
710 PROC_UNLOCK(p->p_pptr);
713 * Save our children's rusage information in our exit rusage.
716 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
720 * Make sure the scheduler takes this thread out of its tables etc.
721 * This will also release this thread's reference to the ucred.
722 * Other thread parts to release include pcb bits and such.
727 #ifndef _SYS_SYSPROTO_H_
736 sys_abort2(struct thread *td, struct abort2_args *uap)
743 if (nargs < 0 || nargs > nitems(uargs))
747 if (uap->args != NULL) {
748 error = copyin(uap->args, uargs,
749 nargs * sizeof(void *));
757 return (kern_abort2(td, uap->why, nargs, uargsp));
763 * why - user pointer to why
764 * nargs - number of arguments copied or -1 if an error occured in copying
765 * args - pointer to an array of pointers in kernel format
768 kern_abort2(struct thread *td, const char *why, int nargs, void **uargs)
770 struct proc *p = td->td_proc;
775 * Do it right now so we can log either proper call of abort2(), or
776 * note, that invalid argument was passed. 512 is big enough to
777 * handle 16 arguments' descriptions with additional comments.
779 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
781 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
782 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
784 * Since we can't return from abort2(), send SIGKILL in cases, where
785 * abort2() was called improperly
788 /* Prevent from DoSes from user-space. */
791 KASSERT(nargs >= 0 && nargs <= 16, ("called with too many args (%d)",
794 * Limit size of 'reason' string to 128. Will fit even when
795 * maximal number of arguments was chosen to be logged.
798 error = sbuf_copyin(sb, why, 128);
802 sbuf_printf(sb, "(null)");
805 sbuf_printf(sb, "(");
806 for (i = 0;i < nargs; i++)
807 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
808 sbuf_printf(sb, ")");
811 * Final stage: arguments were proper, string has been
812 * successfully copied from userspace, and copying pointers
813 * from user-space succeed.
817 if (sig == SIGKILL) {
819 sbuf_printf(sb, " (Reason text inaccessible)");
823 log(LOG_INFO, "%s", sbuf_data(sb));
831 * The dirty work is handled by kern_wait().
834 owait(struct thread *td, struct owait_args *uap __unused)
838 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
840 td->td_retval[1] = status;
843 #endif /* COMPAT_43 */
846 * The dirty work is handled by kern_wait().
849 sys_wait4(struct thread *td, struct wait4_args *uap)
851 struct rusage ru, *rup;
854 if (uap->rusage != NULL)
858 error = kern_wait(td, uap->pid, &status, uap->options, rup);
859 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
860 error = copyout(&status, uap->status, sizeof(status));
861 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
862 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
867 sys_wait6(struct thread *td, struct wait6_args *uap)
869 struct __wrusage wru, *wrup;
875 idtype = uap->idtype;
878 if (uap->wrusage != NULL)
883 if (uap->info != NULL) {
885 bzero(sip, sizeof(*sip));
890 * We expect all callers of wait6() to know about WEXITED and
893 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
895 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
896 error = copyout(&status, uap->status, sizeof(status));
897 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
898 error = copyout(&wru, uap->wrusage, sizeof(wru));
899 if (uap->info != NULL && error == 0)
900 error = copyout(&si, uap->info, sizeof(si));
905 * Reap the remains of a zombie process and optionally return status and
906 * rusage. Asserts and will release both the proctree_lock and the process
907 * lock as part of its work.
910 proc_reap(struct thread *td, struct proc *p, int *status, int options)
914 sx_assert(&proctree_lock, SA_XLOCKED);
915 PROC_LOCK_ASSERT(p, MA_OWNED);
916 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
918 mtx_spin_wait_unlocked(&p->p_slock);
923 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
924 if (options & WNOWAIT) {
926 * Only poll, returning the status. Caller does not wish to
927 * release the proc struct just yet.
930 sx_xunlock(&proctree_lock);
935 sigqueue_take(p->p_ksi);
939 * If we got the child via a ptrace 'attach', we need to give it back
942 if (p->p_oppid != p->p_pptr->p_pid) {
944 t = proc_realparent(p);
948 "wait: traced child %d moved back to parent %d", p->p_pid,
950 proc_reparent(p, t, false);
952 pksignal(t, SIGCHLD, p->p_ksi);
954 cv_broadcast(&p->p_pwait);
956 sx_xunlock(&proctree_lock);
962 * Remove other references to this process to ensure we have an
963 * exclusive reference.
965 sx_xlock(PIDHASHLOCK(p->p_pid));
966 LIST_REMOVE(p, p_hash);
967 sx_xunlock(PIDHASHLOCK(p->p_pid));
968 LIST_REMOVE(p, p_sibling);
969 reaper_abandon_children(p, true);
972 proc_clear_orphan(p);
975 if (p->p_procdesc != NULL)
977 sx_xunlock(&proctree_lock);
979 proc_id_clear(PROC_ID_PID, p->p_pid);
982 knlist_detach(p->p_klist);
987 * Removal from allproc list and process group list paired with
988 * PROC_LOCK which was executed during that time should guarantee
989 * nothing can reach this process anymore. As such further locking
992 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
995 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
999 * Decrement the count of procs running with this uid.
1001 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
1004 * Destroy resource accounting information associated with the process.
1009 racct_sub(p, RACCT_NPROC, 1);
1016 * Free credentials, arguments, and sigacts.
1019 pargs_drop(p->p_args);
1021 sigacts_free(p->p_sigacts);
1022 p->p_sigacts = NULL;
1025 * Do any thread-system specific cleanups.
1030 * Give vm and machine-dependent layer a chance to free anything that
1031 * cpu_exit couldn't release while still running in process context.
1035 mac_proc_destroy(p);
1038 KASSERT(FIRST_THREAD_IN_PROC(p),
1039 ("proc_reap: no residual thread!"));
1040 uma_zfree(proc_zone, p);
1041 atomic_add_int(&nprocs, -1);
1045 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1046 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1051 sx_assert(&proctree_lock, SA_XLOCKED);
1057 if (p->p_procdesc == NULL ||
1058 (p->p_pptr == td->td_proc &&
1059 (p->p_flag & P_TRACED) != 0)) {
1066 if (p->p_pid != (pid_t)id) {
1072 if (p->p_pgid != (pid_t)id) {
1078 if (p->p_session->s_sid != (pid_t)id) {
1084 if (p->p_ucred->cr_uid != (uid_t)id) {
1090 if (p->p_ucred->cr_gid != (gid_t)id) {
1096 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1102 * It seems that the thread structures get zeroed out
1103 * at process exit. This makes it impossible to
1104 * support P_SETID, P_CID or P_CPUID.
1111 if (p_canwait(td, p)) {
1116 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1122 * This special case handles a kthread spawned by linux_clone
1123 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1124 * functions need to be able to distinguish between waiting
1125 * on a process and waiting on a thread. It is a thread if
1126 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1127 * signifies we want to wait for threads and not processes.
1129 if ((p->p_sigparent != SIGCHLD) ^
1130 ((options & WLINUXCLONE) != 0)) {
1135 if (siginfo != NULL) {
1136 bzero(siginfo, sizeof(*siginfo));
1137 siginfo->si_errno = 0;
1140 * SUSv4 requires that the si_signo value is always
1141 * SIGCHLD. Obey it despite the rfork(2) interface
1142 * allows to request other signal for child exit
1145 siginfo->si_signo = SIGCHLD;
1148 * This is still a rough estimate. We will fix the
1149 * cases TRAPPED, STOPPED, and CONTINUED later.
1151 if (WCOREDUMP(p->p_xsig)) {
1152 siginfo->si_code = CLD_DUMPED;
1153 siginfo->si_status = WTERMSIG(p->p_xsig);
1154 } else if (WIFSIGNALED(p->p_xsig)) {
1155 siginfo->si_code = CLD_KILLED;
1156 siginfo->si_status = WTERMSIG(p->p_xsig);
1158 siginfo->si_code = CLD_EXITED;
1159 siginfo->si_status = p->p_xexit;
1162 siginfo->si_pid = p->p_pid;
1163 siginfo->si_uid = p->p_ucred->cr_uid;
1166 * The si_addr field would be useful additional
1167 * detail, but apparently the PC value may be lost
1168 * when we reach this point. bzero() above sets
1169 * siginfo->si_addr to NULL.
1174 * There should be no reason to limit resources usage info to
1175 * exited processes only. A snapshot about any resources used
1176 * by a stopped process may be exactly what is needed.
1178 if (wrusage != NULL) {
1179 rup = &wrusage->wru_self;
1182 calcru(p, &rup->ru_utime, &rup->ru_stime);
1185 rup = &wrusage->wru_children;
1186 *rup = p->p_stats->p_cru;
1187 calccru(p, &rup->ru_utime, &rup->ru_stime);
1190 if (p->p_state == PRS_ZOMBIE && !check_only) {
1191 proc_reap(td, p, status, options);
1198 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1199 struct rusage *rusage)
1201 struct __wrusage wru, *wrup;
1207 * Translate the special pid values into the (idtype, pid)
1208 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1209 * kern_wait6() on its own.
1211 if (pid == WAIT_ANY) {
1214 } else if (pid < 0) {
1228 * For backward compatibility we implicitly add flags WEXITED
1229 * and WTRAPPED here.
1231 options |= WEXITED | WTRAPPED;
1232 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1234 *rusage = wru.wru_self;
1239 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1240 int *status, int options, int si_code)
1244 PROC_LOCK_ASSERT(p, MA_OWNED);
1245 sx_assert(&proctree_lock, SA_XLOCKED);
1246 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1247 si_code == CLD_CONTINUED);
1249 cont = si_code == CLD_CONTINUED;
1250 if ((options & WNOWAIT) == 0) {
1252 p->p_flag &= ~P_CONTINUED;
1254 p->p_flag |= P_WAITED;
1255 if (kern_wait_dequeue_sigchld &&
1256 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1257 PROC_LOCK(td->td_proc);
1258 sigqueue_take(p->p_ksi);
1259 PROC_UNLOCK(td->td_proc);
1262 sx_xunlock(&proctree_lock);
1263 if (siginfo != NULL) {
1264 siginfo->si_code = si_code;
1265 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1268 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1270 td->td_retval[0] = p->p_pid;
1274 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1275 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1279 int error, nfound, ret;
1282 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1283 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1284 AUDIT_ARG_VALUE(options);
1288 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1290 id = (id_t)q->p_pgid;
1295 /* If we don't know the option, just return. */
1296 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1297 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1299 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1301 * We will be unable to find any matching processes,
1302 * because there are no known events to look for.
1303 * Prefer to return error instead of blocking
1310 if (q->p_flag & P_STATCHILD) {
1312 q->p_flag &= ~P_STATCHILD;
1315 sx_xlock(&proctree_lock);
1318 LIST_FOREACH(p, &q->p_children, p_sibling) {
1320 ret = proc_to_reap(td, p, idtype, id, status, options,
1321 wrusage, siginfo, 0);
1324 else if (ret != 1) {
1325 td->td_retval[0] = pid;
1330 PROC_LOCK_ASSERT(p, MA_OWNED);
1332 if ((options & WTRAPPED) != 0 &&
1333 (p->p_flag & P_TRACED) != 0) {
1336 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1337 p->p_suspcount == p->p_numthreads &&
1338 (p->p_flag & P_WAITED) == 0);
1342 "wait: returning trapped pid %d status %#x "
1343 "(xstat %d) xthread %d",
1344 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1345 p->p_xthread != NULL ?
1346 p->p_xthread->td_tid : -1);
1347 report_alive_proc(td, p, siginfo, status,
1348 options, CLD_TRAPPED);
1352 if ((options & WUNTRACED) != 0 &&
1353 (p->p_flag & P_STOPPED_SIG) != 0) {
1355 report = (p->p_suspcount == p->p_numthreads &&
1356 ((p->p_flag & P_WAITED) == 0));
1359 report_alive_proc(td, p, siginfo, status,
1360 options, CLD_STOPPED);
1364 if ((options & WCONTINUED) != 0 &&
1365 (p->p_flag & P_CONTINUED) != 0) {
1366 report_alive_proc(td, p, siginfo, status, options,
1374 * Look in the orphans list too, to allow the parent to
1375 * collect it's child exit status even if child is being
1378 * Debugger detaches from the parent upon successful
1379 * switch-over from parent to child. At this point due to
1380 * re-parenting the parent loses the child to debugger and a
1381 * wait4(2) call would report that it has no children to wait
1382 * for. By maintaining a list of orphans we allow the parent
1383 * to successfully wait until the child becomes a zombie.
1386 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1387 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1390 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1391 (int)td->td_retval[0]));
1399 sx_xunlock(&proctree_lock);
1402 if (options & WNOHANG) {
1403 sx_xunlock(&proctree_lock);
1404 td->td_retval[0] = 0;
1408 if (q->p_flag & P_STATCHILD) {
1409 q->p_flag &= ~P_STATCHILD;
1413 sx_xunlock(&proctree_lock);
1414 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1421 proc_add_orphan(struct proc *child, struct proc *parent)
1424 sx_assert(&proctree_lock, SX_XLOCKED);
1425 KASSERT((child->p_flag & P_TRACED) != 0,
1426 ("proc_add_orphan: not traced"));
1428 if (LIST_EMPTY(&parent->p_orphans)) {
1429 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1430 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1432 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1435 child->p_treeflag |= P_TREE_ORPHANED;
1439 * Make process 'parent' the new parent of process 'child'.
1440 * Must be called with an exclusive hold of proctree lock.
1443 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1446 sx_assert(&proctree_lock, SX_XLOCKED);
1447 PROC_LOCK_ASSERT(child, MA_OWNED);
1448 if (child->p_pptr == parent)
1451 PROC_LOCK(child->p_pptr);
1452 sigqueue_take(child->p_ksi);
1453 PROC_UNLOCK(child->p_pptr);
1454 LIST_REMOVE(child, p_sibling);
1455 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1457 proc_clear_orphan(child);
1458 if ((child->p_flag & P_TRACED) != 0) {
1459 proc_add_orphan(child, child->p_pptr);
1462 child->p_pptr = parent;
1464 child->p_oppid = parent->p_pid;