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
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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>
41 #include "opt_ktrace.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysproto.h>
46 #include <sys/capsicum.h>
47 #include <sys/eventhandler.h>
48 #include <sys/kernel.h>
50 #include <sys/malloc.h>
52 #include <sys/mutex.h>
54 #include <sys/procdesc.h>
58 #include <sys/vmmeter.h>
59 #include <sys/vnode.h>
60 #include <sys/racct.h>
61 #include <sys/resourcevar.h>
63 #include <sys/signalvar.h>
64 #include <sys/sched.h>
66 #include <sys/syscallsubr.h>
67 #include <sys/sysctl.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>
75 #include <sys/sysent.h>
76 #include <sys/timers.h>
77 #include <sys/umtxvar.h>
79 #include <sys/ktrace.h>
82 #include <security/audit/audit.h>
83 #include <security/mac/mac_framework.h>
86 #include <vm/vm_extern.h>
87 #include <vm/vm_param.h>
89 #include <vm/vm_map.h>
90 #include <vm/vm_page.h>
94 #include <sys/dtrace_bsd.h>
95 dtrace_execexit_func_t dtrace_fasttrap_exit;
98 SDT_PROVIDER_DECLARE(proc);
99 SDT_PROBE_DEFINE1(proc, , , exit, "int");
101 static int kern_kill_on_dbg_exit = 1;
102 SYSCTL_INT(_kern, OID_AUTO, kill_on_debugger_exit, CTLFLAG_RWTUN,
103 &kern_kill_on_dbg_exit, 0,
104 "Kill ptraced processes when debugger exits");
106 static bool kern_wait_dequeue_sigchld = 1;
107 SYSCTL_BOOL(_kern, OID_AUTO, wait_dequeue_sigchld, CTLFLAG_RWTUN,
108 &kern_wait_dequeue_sigchld, 0,
109 "Dequeue SIGCHLD on wait(2) for live process");
112 proc_realparent(struct proc *child)
114 struct proc *p, *parent;
116 sx_assert(&proctree_lock, SX_LOCKED);
117 if ((child->p_treeflag & P_TREE_ORPHANED) == 0)
118 return (child->p_pptr->p_pid == child->p_oppid ?
119 child->p_pptr : child->p_reaper);
120 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
121 /* Cannot use LIST_PREV(), since the list head is not known. */
122 p = __containerof(p->p_orphan.le_prev, struct proc,
124 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
125 ("missing P_ORPHAN %p", p));
127 parent = __containerof(p->p_orphan.le_prev, struct proc,
133 reaper_abandon_children(struct proc *p, bool exiting)
135 struct proc *p1, *p2, *ptmp;
137 sx_assert(&proctree_lock, SX_XLOCKED);
138 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
139 if ((p->p_treeflag & P_TREE_REAPER) == 0)
142 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
143 LIST_REMOVE(p2, p_reapsibling);
145 p2->p_reapsubtree = p->p_reapsubtree;
146 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
147 if (exiting && p2->p_pptr == p) {
149 proc_reparent(p2, p1, true);
153 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
154 p->p_treeflag &= ~P_TREE_REAPER;
158 reaper_clear(struct proc *p)
163 sx_assert(&proctree_lock, SX_LOCKED);
164 LIST_REMOVE(p, p_reapsibling);
165 if (p->p_reapsubtree == 1)
168 LIST_FOREACH(p1, &p->p_reaper->p_reaplist, p_reapsibling) {
169 if (p1->p_reapsubtree == p->p_reapsubtree) {
175 proc_id_clear(PROC_ID_REAP, p->p_reapsubtree);
179 proc_clear_orphan(struct proc *p)
183 sx_assert(&proctree_lock, SA_XLOCKED);
184 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
186 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
187 p1 = LIST_NEXT(p, p_orphan);
189 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
190 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
192 LIST_REMOVE(p, p_orphan);
193 p->p_treeflag &= ~P_TREE_ORPHANED;
197 exit_onexit(struct proc *p)
199 MPASS(p->p_numthreads == 1);
200 umtx_thread_exit(FIRST_THREAD_IN_PROC(p));
204 * exit -- death of process.
207 sys_exit(struct thread *td, struct exit_args *uap)
210 exit1(td, uap->rval, 0);
215 proc_set_p2_wexit(struct proc *p)
217 PROC_LOCK_ASSERT(p, MA_OWNED);
218 p->p_flag2 |= P2_WEXIT;
222 * Exit: deallocate address space and other resources, change proc state to
223 * zombie, and unlink proc from allproc and parent's lists. Save exit status
224 * and rusage for wait(). Check for child processes and orphan them.
227 exit1(struct thread *td, int rval, int signo)
229 struct proc *p, *nq, *q, *t;
231 ksiginfo_t *ksi, *ksi1;
234 mtx_assert(&Giant, MA_NOTOWNED);
235 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
236 TSPROCEXIT(td->td_proc->p_pid);
240 * In case we're rebooting we just let init die in order to
241 * work around an issues where pid 1 might get a fatal signal.
242 * For instance, if network interface serving NFS root is
243 * going down due to reboot, page-in requests for text are
246 if (p == initproc && rebooting == 0) {
247 printf("init died (signal %d, exit %d)\n", signo, rval);
248 panic("Going nowhere without my init!");
252 * Process deferred operations, designated with ASTF_KCLEAR.
253 * For instance, we need to deref SU mp, since the thread does
254 * not return to userspace, and wait for geom to stabilize.
259 * MUST abort all other threads before proceeding past here.
262 proc_set_p2_wexit(p);
265 * First check if some other thread or external request got
266 * here before us. If so, act appropriately: exit or suspend.
267 * We must ensure that stop requests are handled before we set
270 thread_suspend_check(0);
271 while (p->p_flag & P_HADTHREADS) {
273 * Kill off the other threads. This requires
274 * some co-operation from other parts of the kernel
275 * so it may not be instantaneous. With this state set
276 * any thread attempting to interruptibly
277 * sleep will return immediately with EINTR or EWOULDBLOCK
278 * which will hopefully force them to back out to userland
279 * freeing resources as they go. Any thread attempting
280 * to return to userland will thread_exit() from ast().
281 * thread_exit() will unsuspend us when the last of the
282 * other threads exits.
283 * If there is already a thread singler after resumption,
284 * calling thread_single() will fail; in that case, we just
285 * re-check all suspension request, the thread should
286 * either be suspended there or exit.
288 if (!thread_single(p, SINGLE_EXIT))
290 * All other activity in this process is now
291 * stopped. Threading support has been turned
296 * Recheck for new stop or suspend requests which
297 * might appear while process lock was dropped in
300 thread_suspend_check(0);
302 KASSERT(p->p_numthreads == 1,
303 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
304 racct_sub(p, RACCT_NTHR, 1);
306 /* Let event handler change exit status */
311 * Ignore any pending request to stop due to a stop signal.
312 * Once P_WEXIT is set, future requests will be ignored as
315 p->p_flag &= ~P_STOPPED_SIG;
316 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
318 /* Note that we are exiting. */
319 p->p_flag |= P_WEXIT;
322 * Wait for any processes that have a hold on our vmspace to
323 * release their reference.
325 while (p->p_lock > 0)
326 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
329 /* Drain the limit callout while we don't have the proc locked */
330 callout_drain(&p->p_limco);
334 * The Sun BSM exit token contains two components: an exit status as
335 * passed to exit(), and a return value to indicate what sort of exit
336 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
337 * what the return value is.
339 AUDIT_ARG_EXIT(rval, 0);
340 AUDIT_SYSCALL_EXIT(0, td);
343 /* Are we a task leader with peers? */
344 if (p->p_peers != NULL && p == p->p_leader) {
345 mtx_lock(&ppeers_lock);
349 kern_psignal(q, SIGKILL);
353 while (p->p_peers != NULL)
354 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
355 mtx_unlock(&ppeers_lock);
361 * Check if any loadable modules need anything done at process exit.
362 * E.g. SYSV IPC stuff.
363 * Event handler could change exit status.
364 * XXX what if one of these generates an error?
366 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
369 * If parent is waiting for us to exit or exec,
370 * P_PPWAIT is set; we will wakeup the parent below.
377 * Stop the real interval timer. If the handler is currently
378 * executing, prevent it from rearming itself and let it finish.
380 if (timevalisset(&p->p_realtimer.it_value) &&
381 callout_stop(&p->p_itcallout) == 0) {
382 timevalclear(&p->p_realtimer.it_interval);
384 callout_drain(&p->p_itcallout);
389 if (p->p_sysent->sv_onexit != NULL)
390 p->p_sysent->sv_onexit(p);
394 * Reset any sigio structures pointing to us as a result of
395 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
397 funsetownlst(&p->p_sigiolst);
400 * Close open files and release open-file table.
407 * Remove ourself from our leader's peer list and wake our leader.
409 if (p->p_leader->p_peers != NULL) {
410 mtx_lock(&ppeers_lock);
411 if (p->p_leader->p_peers != NULL) {
413 while (q->p_peers != p)
415 q->p_peers = p->p_peers;
418 mtx_unlock(&ppeers_lock);
421 exec_free_abi_mappings(p);
423 (void)acct_process(td);
429 * Release reference to text vnode etc
431 if (p->p_textvp != NULL) {
435 if (p->p_textdvp != NULL) {
439 if (p->p_binname != NULL) {
440 free(p->p_binname, M_PARGS);
445 * Release our limits structure.
447 lim_free(p->p_limit);
453 * Call machine-dependent code to release any
454 * machine-dependent resources other than the address space.
455 * The address space is released by "vmspace_exitfree(p)" in
460 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
463 * Remove from allproc. It still sits in the hash.
465 sx_xlock(&allproc_lock);
466 LIST_REMOVE(p, p_list);
470 * Used by ddb's 'ps' command to find this process via the
473 p->p_list.le_prev = NULL;
475 prison_proc_unlink(p->p_ucred->cr_prison, p);
476 sx_xunlock(&allproc_lock);
478 sx_xlock(&proctree_lock);
479 if ((p->p_flag & (P_TRACED | P_PPWAIT | P_PPTRACE)) != 0) {
481 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
486 * killjobc() might drop and re-acquire proctree_lock to
487 * revoke control tty if exiting process was a session leader.
492 * Reparent all children processes:
493 * - traced ones to the original parent (or init if we are that parent)
496 q = LIST_FIRST(&p->p_children);
497 if (q != NULL) /* only need this if any child is S_ZOMB */
499 for (; q != NULL; q = nq) {
500 nq = LIST_NEXT(q, p_sibling);
501 ksi = ksiginfo_alloc(M_WAITOK);
503 q->p_sigparent = SIGCHLD;
505 if ((q->p_flag & P_TRACED) == 0) {
506 proc_reparent(q, q->p_reaper, true);
507 if (q->p_state == PRS_ZOMBIE) {
509 * Inform reaper about the reparented
510 * zombie, since wait(2) has something
511 * new to report. Guarantee queueing
512 * of the SIGCHLD signal, similar to
513 * the _exit() behaviour, by providing
514 * our ksiginfo. Ksi is freed by the
517 if (q->p_ksi == NULL) {
520 ksiginfo_copy(q->p_ksi, ksi);
521 ksi->ksi_flags |= KSI_INS;
525 PROC_LOCK(q->p_reaper);
526 pksignal(q->p_reaper, SIGCHLD, ksi1);
527 PROC_UNLOCK(q->p_reaper);
528 } else if (q->p_pdeathsig > 0) {
530 * The child asked to received a signal
533 kern_psignal(q, q->p_pdeathsig);
537 * Traced processes are killed by default
538 * since their existence means someone is
541 t = proc_realparent(q);
543 proc_reparent(q, q->p_reaper, true);
546 proc_reparent(q, t, true);
550 * Since q was found on our children list, the
551 * proc_reparent() call moved q to the orphan
552 * list due to present P_TRACED flag. Clear
553 * orphan link for q now while q is locked.
555 proc_clear_orphan(q);
556 q->p_flag &= ~P_TRACED;
557 q->p_flag2 &= ~P2_PTRACE_FSTP;
560 FOREACH_THREAD_IN_PROC(q, tdt) {
561 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
565 if (kern_kill_on_dbg_exit) {
566 q->p_flag &= ~P_STOPPED_TRACE;
567 kern_psignal(q, SIGKILL);
568 } else if ((q->p_flag & (P_STOPPED_TRACE |
569 P_STOPPED_SIG)) != 0) {
570 sigqueue_delete_proc(q, SIGTRAP);
580 * Also get rid of our orphans.
582 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
584 KASSERT(q->p_oppid == p->p_pid,
585 ("orphan %p of %p has unexpected oppid %d", q, p,
587 q->p_oppid = q->p_reaper->p_pid;
590 * If we are the real parent of this process
591 * but it has been reparented to a debugger, then
592 * check if it asked for a signal when we exit.
594 if (q->p_pdeathsig > 0)
595 kern_psignal(q, q->p_pdeathsig);
596 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
598 proc_clear_orphan(q);
603 if (SDT_PROBES_ENABLED()) {
604 int reason = CLD_EXITED;
605 if (WCOREDUMP(signo))
607 else if (WIFSIGNALED(signo))
609 SDT_PROBE1(proc, , , exit, reason);
613 /* Save exit status. */
617 if (p->p_sysent->sv_ontdexit != NULL)
618 p->p_sysent->sv_ontdexit(td);
622 * Tell the DTrace fasttrap provider about the exit if it
623 * has declared an interest.
625 if (dtrace_fasttrap_exit)
626 dtrace_fasttrap_exit(p);
630 * Notify interested parties of our demise.
632 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
635 * If this is a process with a descriptor, we may not need to deliver
636 * a signal to the parent. proctree_lock is held over
637 * procdesc_exit() to serialize concurrent calls to close() and
641 if (p->p_procdesc == NULL || procdesc_exit(p)) {
643 * Notify parent that we're gone. If parent has the
644 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
645 * notify process 1 instead (and hope it will handle this
648 PROC_LOCK(p->p_pptr);
649 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
650 if (p->p_pptr->p_sigacts->ps_flag &
651 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
654 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
657 proc_reparent(p, p->p_reaper, true);
658 p->p_sigparent = SIGCHLD;
659 PROC_LOCK(p->p_pptr);
662 * Notify parent, so in case he was wait(2)ing or
663 * executing waitpid(2) with our pid, he will
668 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
670 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
672 } else if (p->p_sigparent != 0) {
673 if (p->p_sigparent == SIGCHLD) {
675 } else { /* LINUX thread */
680 PROC_LOCK(p->p_pptr);
681 sx_xunlock(&proctree_lock);
683 if (signal_parent == 1) {
685 } else if (signal_parent == 2) {
686 kern_psignal(p->p_pptr, p->p_sigparent);
689 /* Tell the prison that we are gone. */
690 prison_proc_free(p->p_ucred->cr_prison);
693 * The state PRS_ZOMBIE prevents other processes from sending
694 * signal to the process, to avoid memory leak, we free memory
695 * for signal queue at the time when the state is set.
697 sigqueue_flush(&p->p_sigqueue);
698 sigqueue_flush(&td->td_sigqueue);
701 * We have to wait until after acquiring all locks before
702 * changing p_state. We need to avoid all possible context
703 * switches (including ones from blocking on a mutex) while
704 * marked as a zombie. We also have to set the zombie state
705 * before we release the parent process' proc lock to avoid
706 * a lost wakeup. So, we first call wakeup, then we grab the
707 * sched lock, update the state, and release the parent process'
711 cv_broadcast(&p->p_pwait);
712 sched_exit(p->p_pptr, td);
714 p->p_state = PRS_ZOMBIE;
715 PROC_UNLOCK(p->p_pptr);
718 * Save our children's rusage information in our exit rusage.
721 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
725 * Make sure the scheduler takes this thread out of its tables etc.
726 * This will also release this thread's reference to the ucred.
727 * Other thread parts to release include pcb bits and such.
732 #ifndef _SYS_SYSPROTO_H_
741 sys_abort2(struct thread *td, struct abort2_args *uap)
748 if (nargs < 0 || nargs > nitems(uargs))
752 if (uap->args != NULL) {
753 error = copyin(uap->args, uargs,
754 nargs * sizeof(void *));
762 return (kern_abort2(td, uap->why, nargs, uargsp));
768 * why - user pointer to why
769 * nargs - number of arguments copied or -1 if an error occurred in copying
770 * args - pointer to an array of pointers in kernel format
773 kern_abort2(struct thread *td, const char *why, int nargs, void **uargs)
775 struct proc *p = td->td_proc;
780 * Do it right now so we can log either proper call of abort2(), or
781 * note, that invalid argument was passed. 512 is big enough to
782 * handle 16 arguments' descriptions with additional comments.
784 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
786 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
787 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
789 * Since we can't return from abort2(), send SIGKILL in cases, where
790 * abort2() was called improperly
793 /* Prevent from DoSes from user-space. */
796 KASSERT(nargs >= 0 && nargs <= 16, ("called with too many args (%d)",
799 * Limit size of 'reason' string to 128. Will fit even when
800 * maximal number of arguments was chosen to be logged.
803 error = sbuf_copyin(sb, why, 128);
807 sbuf_printf(sb, "(null)");
810 sbuf_printf(sb, "(");
811 for (i = 0;i < nargs; i++)
812 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
813 sbuf_printf(sb, ")");
816 * Final stage: arguments were proper, string has been
817 * successfully copied from userspace, and copying pointers
818 * from user-space succeed.
822 if (sig == SIGKILL) {
824 sbuf_printf(sb, " (Reason text inaccessible)");
828 log(LOG_INFO, "%s", sbuf_data(sb));
836 * The dirty work is handled by kern_wait().
839 owait(struct thread *td, struct owait_args *uap __unused)
843 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
845 td->td_retval[1] = status;
848 #endif /* COMPAT_43 */
851 * The dirty work is handled by kern_wait().
854 sys_wait4(struct thread *td, struct wait4_args *uap)
856 struct rusage ru, *rup;
859 if (uap->rusage != NULL)
863 error = kern_wait(td, uap->pid, &status, uap->options, rup);
864 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
865 error = copyout(&status, uap->status, sizeof(status));
866 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
867 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
872 sys_wait6(struct thread *td, struct wait6_args *uap)
874 struct __wrusage wru, *wrup;
880 idtype = uap->idtype;
883 if (uap->wrusage != NULL)
888 if (uap->info != NULL) {
890 bzero(sip, sizeof(*sip));
895 * We expect all callers of wait6() to know about WEXITED and
898 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
900 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
901 error = copyout(&status, uap->status, sizeof(status));
902 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
903 error = copyout(&wru, uap->wrusage, sizeof(wru));
904 if (uap->info != NULL && error == 0)
905 error = copyout(&si, uap->info, sizeof(si));
910 * Reap the remains of a zombie process and optionally return status and
911 * rusage. Asserts and will release both the proctree_lock and the process
912 * lock as part of its work.
915 proc_reap(struct thread *td, struct proc *p, int *status, int options)
919 sx_assert(&proctree_lock, SA_XLOCKED);
920 PROC_LOCK_ASSERT(p, MA_OWNED);
921 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
923 mtx_spin_wait_unlocked(&p->p_slock);
928 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
929 if (options & WNOWAIT) {
931 * Only poll, returning the status. Caller does not wish to
932 * release the proc struct just yet.
935 sx_xunlock(&proctree_lock);
940 sigqueue_take(p->p_ksi);
944 * If we got the child via a ptrace 'attach', we need to give it back
947 if (p->p_oppid != p->p_pptr->p_pid) {
949 t = proc_realparent(p);
953 "wait: traced child %d moved back to parent %d", p->p_pid,
955 proc_reparent(p, t, false);
957 pksignal(t, SIGCHLD, p->p_ksi);
959 cv_broadcast(&p->p_pwait);
961 sx_xunlock(&proctree_lock);
967 * Remove other references to this process to ensure we have an
968 * exclusive reference.
970 sx_xlock(PIDHASHLOCK(p->p_pid));
971 LIST_REMOVE(p, p_hash);
972 sx_xunlock(PIDHASHLOCK(p->p_pid));
973 LIST_REMOVE(p, p_sibling);
974 reaper_abandon_children(p, true);
977 proc_clear_orphan(p);
980 if (p->p_procdesc != NULL)
982 sx_xunlock(&proctree_lock);
984 proc_id_clear(PROC_ID_PID, p->p_pid);
987 knlist_detach(p->p_klist);
992 * Removal from allproc list and process group list paired with
993 * PROC_LOCK which was executed during that time should guarantee
994 * nothing can reach this process anymore. As such further locking
997 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
1000 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
1004 * Decrement the count of procs running with this uid.
1006 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
1009 * Destroy resource accounting information associated with the process.
1014 racct_sub(p, RACCT_NPROC, 1);
1021 * Free credentials, arguments, and sigacts.
1024 pargs_drop(p->p_args);
1026 sigacts_free(p->p_sigacts);
1027 p->p_sigacts = NULL;
1030 * Do any thread-system specific cleanups.
1035 * Give vm and machine-dependent layer a chance to free anything that
1036 * cpu_exit couldn't release while still running in process context.
1040 mac_proc_destroy(p);
1043 KASSERT(FIRST_THREAD_IN_PROC(p),
1044 ("proc_reap: no residual thread!"));
1045 uma_zfree(proc_zone, p);
1046 atomic_add_int(&nprocs, -1);
1050 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1051 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1056 sx_assert(&proctree_lock, SA_XLOCKED);
1062 if (p->p_procdesc == NULL ||
1063 (p->p_pptr == td->td_proc &&
1064 (p->p_flag & P_TRACED) != 0)) {
1071 if (p->p_pid != (pid_t)id) {
1077 if (p->p_pgid != (pid_t)id) {
1083 if (p->p_session->s_sid != (pid_t)id) {
1089 if (p->p_ucred->cr_uid != (uid_t)id) {
1095 if (p->p_ucred->cr_gid != (gid_t)id) {
1101 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1107 * It seems that the thread structures get zeroed out
1108 * at process exit. This makes it impossible to
1109 * support P_SETID, P_CID or P_CPUID.
1116 if (p_canwait(td, p)) {
1121 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1127 * This special case handles a kthread spawned by linux_clone
1128 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1129 * functions need to be able to distinguish between waiting
1130 * on a process and waiting on a thread. It is a thread if
1131 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1132 * signifies we want to wait for threads and not processes.
1134 if ((p->p_sigparent != SIGCHLD) ^
1135 ((options & WLINUXCLONE) != 0)) {
1140 if (siginfo != NULL) {
1141 bzero(siginfo, sizeof(*siginfo));
1142 siginfo->si_errno = 0;
1145 * SUSv4 requires that the si_signo value is always
1146 * SIGCHLD. Obey it despite the rfork(2) interface
1147 * allows to request other signal for child exit
1150 siginfo->si_signo = SIGCHLD;
1153 * This is still a rough estimate. We will fix the
1154 * cases TRAPPED, STOPPED, and CONTINUED later.
1156 if (WCOREDUMP(p->p_xsig)) {
1157 siginfo->si_code = CLD_DUMPED;
1158 siginfo->si_status = WTERMSIG(p->p_xsig);
1159 } else if (WIFSIGNALED(p->p_xsig)) {
1160 siginfo->si_code = CLD_KILLED;
1161 siginfo->si_status = WTERMSIG(p->p_xsig);
1163 siginfo->si_code = CLD_EXITED;
1164 siginfo->si_status = p->p_xexit;
1167 siginfo->si_pid = p->p_pid;
1168 siginfo->si_uid = p->p_ucred->cr_uid;
1171 * The si_addr field would be useful additional
1172 * detail, but apparently the PC value may be lost
1173 * when we reach this point. bzero() above sets
1174 * siginfo->si_addr to NULL.
1179 * There should be no reason to limit resources usage info to
1180 * exited processes only. A snapshot about any resources used
1181 * by a stopped process may be exactly what is needed.
1183 if (wrusage != NULL) {
1184 rup = &wrusage->wru_self;
1187 calcru(p, &rup->ru_utime, &rup->ru_stime);
1190 rup = &wrusage->wru_children;
1191 *rup = p->p_stats->p_cru;
1192 calccru(p, &rup->ru_utime, &rup->ru_stime);
1195 if (p->p_state == PRS_ZOMBIE && !check_only) {
1196 proc_reap(td, p, status, options);
1203 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1204 struct rusage *rusage)
1206 struct __wrusage wru, *wrup;
1212 * Translate the special pid values into the (idtype, pid)
1213 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1214 * kern_wait6() on its own.
1216 if (pid == WAIT_ANY) {
1219 } else if (pid < 0) {
1233 * For backward compatibility we implicitly add flags WEXITED
1234 * and WTRAPPED here.
1236 options |= WEXITED | WTRAPPED;
1237 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1239 *rusage = wru.wru_self;
1244 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1245 int *status, int options, int si_code)
1249 PROC_LOCK_ASSERT(p, MA_OWNED);
1250 sx_assert(&proctree_lock, SA_XLOCKED);
1251 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1252 si_code == CLD_CONTINUED);
1254 cont = si_code == CLD_CONTINUED;
1255 if ((options & WNOWAIT) == 0) {
1257 p->p_flag &= ~P_CONTINUED;
1259 p->p_flag |= P_WAITED;
1260 if (kern_wait_dequeue_sigchld &&
1261 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1262 PROC_LOCK(td->td_proc);
1263 sigqueue_take(p->p_ksi);
1264 PROC_UNLOCK(td->td_proc);
1267 sx_xunlock(&proctree_lock);
1268 if (siginfo != NULL) {
1269 siginfo->si_code = si_code;
1270 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1273 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1274 td->td_retval[0] = p->p_pid;
1279 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1280 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1284 int error, nfound, ret;
1287 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1288 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1289 AUDIT_ARG_VALUE(options);
1293 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1295 id = (id_t)q->p_pgid;
1300 /* If we don't know the option, just return. */
1301 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1302 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1304 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1306 * We will be unable to find any matching processes,
1307 * because there are no known events to look for.
1308 * Prefer to return error instead of blocking
1315 if (q->p_flag & P_STATCHILD) {
1317 q->p_flag &= ~P_STATCHILD;
1320 sx_xlock(&proctree_lock);
1323 LIST_FOREACH(p, &q->p_children, p_sibling) {
1325 ret = proc_to_reap(td, p, idtype, id, status, options,
1326 wrusage, siginfo, 0);
1329 else if (ret != 1) {
1330 td->td_retval[0] = pid;
1335 PROC_LOCK_ASSERT(p, MA_OWNED);
1337 if ((options & WTRAPPED) != 0 &&
1338 (p->p_flag & P_TRACED) != 0) {
1341 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1342 p->p_suspcount == p->p_numthreads &&
1343 (p->p_flag & P_WAITED) == 0);
1347 "wait: returning trapped pid %d status %#x "
1348 "(xstat %d) xthread %d",
1349 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1350 p->p_xthread != NULL ?
1351 p->p_xthread->td_tid : -1);
1352 report_alive_proc(td, p, siginfo, status,
1353 options, CLD_TRAPPED);
1357 if ((options & WUNTRACED) != 0 &&
1358 (p->p_flag & P_STOPPED_SIG) != 0) {
1360 report = (p->p_suspcount == p->p_numthreads &&
1361 ((p->p_flag & P_WAITED) == 0));
1364 report_alive_proc(td, p, siginfo, status,
1365 options, CLD_STOPPED);
1369 if ((options & WCONTINUED) != 0 &&
1370 (p->p_flag & P_CONTINUED) != 0) {
1371 report_alive_proc(td, p, siginfo, status, options,
1379 * Look in the orphans list too, to allow the parent to
1380 * collect it's child exit status even if child is being
1383 * Debugger detaches from the parent upon successful
1384 * switch-over from parent to child. At this point due to
1385 * re-parenting the parent loses the child to debugger and a
1386 * wait4(2) call would report that it has no children to wait
1387 * for. By maintaining a list of orphans we allow the parent
1388 * to successfully wait until the child becomes a zombie.
1391 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1392 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1395 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1396 (int)td->td_retval[0]));
1404 sx_xunlock(&proctree_lock);
1407 if (options & WNOHANG) {
1408 sx_xunlock(&proctree_lock);
1409 td->td_retval[0] = 0;
1413 if (q->p_flag & P_STATCHILD) {
1414 q->p_flag &= ~P_STATCHILD;
1418 sx_xunlock(&proctree_lock);
1419 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1426 proc_add_orphan(struct proc *child, struct proc *parent)
1429 sx_assert(&proctree_lock, SX_XLOCKED);
1430 KASSERT((child->p_flag & P_TRACED) != 0,
1431 ("proc_add_orphan: not traced"));
1433 if (LIST_EMPTY(&parent->p_orphans)) {
1434 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1435 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1437 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1440 child->p_treeflag |= P_TREE_ORPHANED;
1444 * Make process 'parent' the new parent of process 'child'.
1445 * Must be called with an exclusive hold of proctree lock.
1448 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1451 sx_assert(&proctree_lock, SX_XLOCKED);
1452 PROC_LOCK_ASSERT(child, MA_OWNED);
1453 if (child->p_pptr == parent)
1456 PROC_LOCK(child->p_pptr);
1457 sigqueue_take(child->p_ksi);
1458 PROC_UNLOCK(child->p_pptr);
1459 LIST_REMOVE(child, p_sibling);
1460 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1462 proc_clear_orphan(child);
1463 if ((child->p_flag & P_TRACED) != 0) {
1464 proc_add_orphan(child, child->p_pptr);
1467 child->p_pptr = parent;
1469 child->p_oppid = parent->p_pid;