2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
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7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
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11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
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18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
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22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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34 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "opt_compat.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>
49 #include <sys/malloc.h>
51 #include <sys/mutex.h>
53 #include <sys/procdesc.h>
54 #include <sys/pioctl.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/syslog.h>
68 #include <sys/ptrace.h>
69 #include <sys/acct.h> /* for acct_process() function prototype */
70 #include <sys/filedesc.h>
76 #include <sys/ktrace.h>
79 #include <security/audit/audit.h>
80 #include <security/mac/mac_framework.h>
83 #include <vm/vm_extern.h>
84 #include <vm/vm_param.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_page.h>
89 #include <vm/vm_domain.h>
92 #include <sys/dtrace_bsd.h>
93 dtrace_execexit_func_t dtrace_fasttrap_exit;
96 SDT_PROVIDER_DECLARE(proc);
97 SDT_PROBE_DEFINE1(proc, , , exit, "int");
99 /* Hook for NFS teardown procedure. */
100 void (*nlminfo_release_p)(struct proc *p);
103 proc_realparent(struct proc *child)
105 struct proc *p, *parent;
107 sx_assert(&proctree_lock, SX_LOCKED);
108 if ((child->p_treeflag & P_TREE_ORPHANED) == 0) {
109 if (child->p_oppid == 0 ||
110 child->p_pptr->p_pid == child->p_oppid)
111 parent = child->p_pptr;
116 for (p = child; (p->p_treeflag & P_TREE_FIRST_ORPHAN) == 0;) {
117 /* Cannot use LIST_PREV(), since the list head is not known. */
118 p = __containerof(p->p_orphan.le_prev, struct proc,
120 KASSERT((p->p_treeflag & P_TREE_ORPHANED) != 0,
121 ("missing P_ORPHAN %p", p));
123 parent = __containerof(p->p_orphan.le_prev, struct proc,
129 reaper_abandon_children(struct proc *p, bool exiting)
131 struct proc *p1, *p2, *ptmp;
133 sx_assert(&proctree_lock, SX_LOCKED);
134 KASSERT(p != initproc, ("reaper_abandon_children for initproc"));
135 if ((p->p_treeflag & P_TREE_REAPER) == 0)
138 LIST_FOREACH_SAFE(p2, &p->p_reaplist, p_reapsibling, ptmp) {
139 LIST_REMOVE(p2, p_reapsibling);
141 p2->p_reapsubtree = p->p_reapsubtree;
142 LIST_INSERT_HEAD(&p1->p_reaplist, p2, p_reapsibling);
143 if (exiting && p2->p_pptr == p) {
145 proc_reparent(p2, p1);
149 KASSERT(LIST_EMPTY(&p->p_reaplist), ("p_reaplist not empty"));
150 p->p_treeflag &= ~P_TREE_REAPER;
154 clear_orphan(struct proc *p)
158 sx_assert(&proctree_lock, SA_XLOCKED);
159 if ((p->p_treeflag & P_TREE_ORPHANED) == 0)
161 if ((p->p_treeflag & P_TREE_FIRST_ORPHAN) != 0) {
162 p1 = LIST_NEXT(p, p_orphan);
164 p1->p_treeflag |= P_TREE_FIRST_ORPHAN;
165 p->p_treeflag &= ~P_TREE_FIRST_ORPHAN;
167 LIST_REMOVE(p, p_orphan);
168 p->p_treeflag &= ~P_TREE_ORPHANED;
172 * exit -- death of process.
175 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
178 exit1(td, uap->rval, 0);
183 * Exit: deallocate address space and other resources, change proc state to
184 * zombie, and unlink proc from allproc and parent's lists. Save exit status
185 * and rusage for wait(). Check for child processes and orphan them.
188 exit1(struct thread *td, int rval, int signo)
190 struct proc *p, *nq, *q, *t;
193 mtx_assert(&Giant, MA_NOTOWNED);
194 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
198 * XXX in case we're rebooting we just let init die in order to
199 * work around an unsolved stack overflow seen very late during
200 * shutdown on sparc64 when the gmirror worker process exists.
202 if (p == initproc && rebooting == 0) {
203 printf("init died (signal %d, exit %d)\n", signo, rval);
204 panic("Going nowhere without my init!");
208 * Deref SU mp, since the thread does not return to userspace.
210 td_softdep_cleanup(td);
213 * MUST abort all other threads before proceeding past here.
217 * First check if some other thread or external request got
218 * here before us. If so, act appropriately: exit or suspend.
219 * We must ensure that stop requests are handled before we set
222 thread_suspend_check(0);
223 while (p->p_flag & P_HADTHREADS) {
225 * Kill off the other threads. This requires
226 * some co-operation from other parts of the kernel
227 * so it may not be instantaneous. With this state set
228 * any thread entering the kernel from userspace will
229 * thread_exit() in trap(). Any thread attempting to
230 * sleep will return immediately with EINTR or EWOULDBLOCK
231 * which will hopefully force them to back out to userland
232 * freeing resources as they go. Any thread attempting
233 * to return to userland will thread_exit() from userret().
234 * thread_exit() will unsuspend us when the last of the
235 * other threads exits.
236 * If there is already a thread singler after resumption,
237 * calling thread_single will fail; in that case, we just
238 * re-check all suspension request, the thread should
239 * either be suspended there or exit.
241 if (!thread_single(p, SINGLE_EXIT))
243 * All other activity in this process is now
244 * stopped. Threading support has been turned
249 * Recheck for new stop or suspend requests which
250 * might appear while process lock was dropped in
253 thread_suspend_check(0);
255 KASSERT(p->p_numthreads == 1,
256 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
257 racct_sub(p, RACCT_NTHR, 1);
259 /* Let event handler change exit status */
264 * Wakeup anyone in procfs' PIOCWAIT. They should have a hold
265 * on our vmspace, so we should block below until they have
266 * released their reference to us. Note that if they have
267 * requested S_EXIT stops we will block here until they ack
270 _STOPEVENT(p, S_EXIT, 0);
273 * Ignore any pending request to stop due to a stop signal.
274 * Once P_WEXIT is set, future requests will be ignored as
277 p->p_flag &= ~P_STOPPED_SIG;
278 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
281 * Note that we are exiting and do another wakeup of anyone in
282 * PIOCWAIT in case they aren't listening for S_EXIT stops or
283 * decided to wait again after we told them we are exiting.
285 p->p_flag |= P_WEXIT;
289 * Wait for any processes that have a hold on our vmspace to
290 * release their reference.
292 while (p->p_lock > 0)
293 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
296 /* Drain the limit callout while we don't have the proc locked */
297 callout_drain(&p->p_limco);
301 * The Sun BSM exit token contains two components: an exit status as
302 * passed to exit(), and a return value to indicate what sort of exit
303 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
304 * what the return value is.
306 AUDIT_ARG_EXIT(rval, 0);
307 AUDIT_SYSCALL_EXIT(0, td);
310 /* Are we a task leader with peers? */
311 if (p->p_peers != NULL && p == p->p_leader) {
312 mtx_lock(&ppeers_lock);
316 kern_psignal(q, SIGKILL);
320 while (p->p_peers != NULL)
321 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
322 mtx_unlock(&ppeers_lock);
326 * Check if any loadable modules need anything done at process exit.
327 * E.g. SYSV IPC stuff.
328 * Event handler could change exit status.
329 * XXX what if one of these generates an error?
331 EVENTHANDLER_INVOKE(process_exit, p);
334 * If parent is waiting for us to exit or exec,
335 * P_PPWAIT is set; we will wakeup the parent below.
339 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
343 * Stop the real interval timer. If the handler is currently
344 * executing, prevent it from rearming itself and let it finish.
346 if (timevalisset(&p->p_realtimer.it_value) &&
347 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
348 timevalclear(&p->p_realtimer.it_interval);
349 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
350 KASSERT(!timevalisset(&p->p_realtimer.it_value),
351 ("realtime timer is still armed"));
356 umtx_thread_exit(td);
359 * Reset any sigio structures pointing to us as a result of
360 * F_SETOWN with our pid.
362 funsetownlst(&p->p_sigiolst);
365 * If this process has an nlminfo data area (for lockd), release it
367 if (nlminfo_release_p != NULL && p->p_nlminfo != NULL)
368 (*nlminfo_release_p)(p);
371 * Close open files and release open-file table.
377 * If this thread tickled GEOM, we need to wait for the giggling to
378 * stop before we return to userland
380 if (td->td_pflags & TDP_GEOM)
384 * Remove ourself from our leader's peer list and wake our leader.
386 if (p->p_leader->p_peers != NULL) {
387 mtx_lock(&ppeers_lock);
388 if (p->p_leader->p_peers != NULL) {
390 while (q->p_peers != p)
392 q->p_peers = p->p_peers;
395 mtx_unlock(&ppeers_lock);
400 (void)acct_process(td);
406 * Release reference to text vnode
408 if (p->p_textvp != NULL) {
414 * Release our limits structure.
416 lim_free(p->p_limit);
422 * Remove proc from allproc queue and pidhash chain.
423 * Place onto zombproc. Unlink from parent's child list.
425 sx_xlock(&allproc_lock);
426 LIST_REMOVE(p, p_list);
427 LIST_INSERT_HEAD(&zombproc, p, p_list);
428 LIST_REMOVE(p, p_hash);
429 sx_xunlock(&allproc_lock);
432 * Call machine-dependent code to release any
433 * machine-dependent resources other than the address space.
434 * The address space is released by "vmspace_exitfree(p)" in
439 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
442 * Reparent all children processes:
443 * - traced ones to the original parent (or init if we are that parent)
446 sx_xlock(&proctree_lock);
447 q = LIST_FIRST(&p->p_children);
448 if (q != NULL) /* only need this if any child is S_ZOMB */
450 for (; q != NULL; q = nq) {
451 nq = LIST_NEXT(q, p_sibling);
453 q->p_sigparent = SIGCHLD;
455 if (!(q->p_flag & P_TRACED)) {
456 proc_reparent(q, q->p_reaper);
457 if (q->p_state == PRS_ZOMBIE) {
458 PROC_LOCK(q->p_reaper);
459 pksignal(q->p_reaper, SIGCHLD, q->p_ksi);
460 PROC_UNLOCK(q->p_reaper);
464 * Traced processes are killed since their existence
465 * means someone is screwing up.
467 t = proc_realparent(q);
469 proc_reparent(q, q->p_reaper);
476 * Since q was found on our children list, the
477 * proc_reparent() call moved q to the orphan
478 * list due to present P_TRACED flag. Clear
479 * orphan link for q now while q is locked.
482 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
483 q->p_flag2 &= ~P2_PTRACE_FSTP;
485 FOREACH_THREAD_IN_PROC(q, tdt) {
486 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
489 kern_psignal(q, SIGKILL);
495 * Also get rid of our orphans.
497 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
499 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
505 /* Save exit status. */
509 /* Tell the prison that we are gone. */
510 prison_proc_free(p->p_ucred->cr_prison);
514 * Tell the DTrace fasttrap provider about the exit if it
515 * has declared an interest.
517 if (dtrace_fasttrap_exit)
518 dtrace_fasttrap_exit(p);
522 * Notify interested parties of our demise.
524 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
527 int reason = CLD_EXITED;
528 if (WCOREDUMP(signo))
530 else if (WIFSIGNALED(signo))
532 SDT_PROBE1(proc, , , exit, reason);
536 * If this is a process with a descriptor, we may not need to deliver
537 * a signal to the parent. proctree_lock is held over
538 * procdesc_exit() to serialize concurrent calls to close() and
541 if (p->p_procdesc == NULL || procdesc_exit(p)) {
543 * Notify parent that we're gone. If parent has the
544 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
545 * notify process 1 instead (and hope it will handle this
548 PROC_LOCK(p->p_pptr);
549 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
550 if (p->p_pptr->p_sigacts->ps_flag &
551 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
554 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
557 proc_reparent(p, p->p_reaper);
558 p->p_sigparent = SIGCHLD;
559 PROC_LOCK(p->p_pptr);
562 * Notify parent, so in case he was wait(2)ing or
563 * executing waitpid(2) with our pid, he will
568 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
570 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc)
572 else if (p->p_sigparent != 0) {
573 if (p->p_sigparent == SIGCHLD)
575 else /* LINUX thread */
576 kern_psignal(p->p_pptr, p->p_sigparent);
579 PROC_LOCK(p->p_pptr);
580 sx_xunlock(&proctree_lock);
583 * The state PRS_ZOMBIE prevents other proesses from sending
584 * signal to the process, to avoid memory leak, we free memory
585 * for signal queue at the time when the state is set.
587 sigqueue_flush(&p->p_sigqueue);
588 sigqueue_flush(&td->td_sigqueue);
591 * We have to wait until after acquiring all locks before
592 * changing p_state. We need to avoid all possible context
593 * switches (including ones from blocking on a mutex) while
594 * marked as a zombie. We also have to set the zombie state
595 * before we release the parent process' proc lock to avoid
596 * a lost wakeup. So, we first call wakeup, then we grab the
597 * sched lock, update the state, and release the parent process'
601 cv_broadcast(&p->p_pwait);
602 sched_exit(p->p_pptr, td);
604 p->p_state = PRS_ZOMBIE;
605 PROC_UNLOCK(p->p_pptr);
608 * Save our children's rusage information in our exit rusage.
611 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
615 * Make sure the scheduler takes this thread out of its tables etc.
616 * This will also release this thread's reference to the ucred.
617 * Other thread parts to release include pcb bits and such.
623 #ifndef _SYS_SYSPROTO_H_
632 sys_abort2(struct thread *td, struct abort2_args *uap)
634 struct proc *p = td->td_proc;
640 * Do it right now so we can log either proper call of abort2(), or
641 * note, that invalid argument was passed. 512 is big enough to
642 * handle 16 arguments' descriptions with additional comments.
644 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
646 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
647 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
649 * Since we can't return from abort2(), send SIGKILL in cases, where
650 * abort2() was called improperly
653 /* Prevent from DoSes from user-space. */
654 if (uap->nargs < 0 || uap->nargs > 16)
656 if (uap->nargs > 0) {
657 if (uap->args == NULL)
659 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
664 * Limit size of 'reason' string to 128. Will fit even when
665 * maximal number of arguments was chosen to be logged.
667 if (uap->why != NULL) {
668 error = sbuf_copyin(sb, uap->why, 128);
672 sbuf_printf(sb, "(null)");
674 if (uap->nargs > 0) {
675 sbuf_printf(sb, "(");
676 for (i = 0;i < uap->nargs; i++)
677 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
678 sbuf_printf(sb, ")");
681 * Final stage: arguments were proper, string has been
682 * successfully copied from userspace, and copying pointers
683 * from user-space succeed.
687 if (sig == SIGKILL) {
689 sbuf_printf(sb, " (Reason text inaccessible)");
693 log(LOG_INFO, "%s", sbuf_data(sb));
702 * The dirty work is handled by kern_wait().
705 owait(struct thread *td, struct owait_args *uap __unused)
709 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
711 td->td_retval[1] = status;
714 #endif /* COMPAT_43 */
717 * The dirty work is handled by kern_wait().
720 sys_wait4(struct thread *td, struct wait4_args *uap)
722 struct rusage ru, *rup;
725 if (uap->rusage != NULL)
729 error = kern_wait(td, uap->pid, &status, uap->options, rup);
730 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
731 error = copyout(&status, uap->status, sizeof(status));
732 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
733 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
738 sys_wait6(struct thread *td, struct wait6_args *uap)
740 struct __wrusage wru, *wrup;
746 idtype = uap->idtype;
749 if (uap->wrusage != NULL)
754 if (uap->info != NULL) {
756 bzero(sip, sizeof(*sip));
761 * We expect all callers of wait6() to know about WEXITED and
764 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
766 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
767 error = copyout(&status, uap->status, sizeof(status));
768 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
769 error = copyout(&wru, uap->wrusage, sizeof(wru));
770 if (uap->info != NULL && error == 0)
771 error = copyout(&si, uap->info, sizeof(si));
776 * Reap the remains of a zombie process and optionally return status and
777 * rusage. Asserts and will release both the proctree_lock and the process
778 * lock as part of its work.
781 proc_reap(struct thread *td, struct proc *p, int *status, int options)
785 sx_assert(&proctree_lock, SA_XLOCKED);
786 PROC_LOCK_ASSERT(p, MA_OWNED);
787 PROC_SLOCK_ASSERT(p, MA_OWNED);
788 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
794 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
795 if (options & WNOWAIT) {
797 * Only poll, returning the status. Caller does not wish to
798 * release the proc struct just yet.
801 sx_xunlock(&proctree_lock);
806 sigqueue_take(p->p_ksi);
810 * If we got the child via a ptrace 'attach', we need to give it back
813 if (p->p_oppid != 0 && p->p_oppid != p->p_pptr->p_pid) {
815 t = proc_realparent(p);
819 "wait: traced child %d moved back to parent %d", p->p_pid,
824 pksignal(t, SIGCHLD, p->p_ksi);
826 cv_broadcast(&p->p_pwait);
828 sx_xunlock(&proctree_lock);
835 * Remove other references to this process to ensure we have an
836 * exclusive reference.
838 sx_xlock(&allproc_lock);
839 LIST_REMOVE(p, p_list); /* off zombproc */
840 sx_xunlock(&allproc_lock);
841 LIST_REMOVE(p, p_sibling);
842 reaper_abandon_children(p, true);
843 LIST_REMOVE(p, p_reapsibling);
848 if (p->p_procdesc != NULL)
850 sx_xunlock(&proctree_lock);
853 knlist_detach(p->p_klist);
858 * Removal from allproc list and process group list paired with
859 * PROC_LOCK which was executed during that time should guarantee
860 * nothing can reach this process anymore. As such further locking
863 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
866 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
870 * Decrement the count of procs running with this uid.
872 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
875 * Destroy resource accounting information associated with the process.
880 racct_sub(p, RACCT_NPROC, 1);
887 * Free credentials, arguments, and sigacts.
890 proc_set_cred(p, NULL);
891 pargs_drop(p->p_args);
893 sigacts_free(p->p_sigacts);
897 * Do any thread-system specific cleanups.
902 * Give vm and machine-dependent layer a chance to free anything that
903 * cpu_exit couldn't release while still running in process context.
910 * Free any domain policy that's still hiding around.
912 vm_domain_policy_cleanup(&p->p_vm_dom_policy);
914 KASSERT(FIRST_THREAD_IN_PROC(p),
915 ("proc_reap: no residual thread!"));
916 uma_zfree(proc_zone, p);
917 atomic_add_int(&nprocs, -1);
921 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
922 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
927 sx_assert(&proctree_lock, SA_XLOCKED);
933 if (p->p_procdesc != NULL) {
939 if (p->p_pid != (pid_t)id) {
945 if (p->p_pgid != (pid_t)id) {
951 if (p->p_session->s_sid != (pid_t)id) {
957 if (p->p_ucred->cr_uid != (uid_t)id) {
963 if (p->p_ucred->cr_gid != (gid_t)id) {
969 if (p->p_ucred->cr_prison->pr_id != (int)id) {
975 * It seems that the thread structures get zeroed out
976 * at process exit. This makes it impossible to
977 * support P_SETID, P_CID or P_CPUID.
984 if (p_canwait(td, p)) {
989 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
995 * This special case handles a kthread spawned by linux_clone
996 * (see linux_misc.c). The linux_wait4 and linux_waitpid
997 * functions need to be able to distinguish between waiting
998 * on a process and waiting on a thread. It is a thread if
999 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1000 * signifies we want to wait for threads and not processes.
1002 if ((p->p_sigparent != SIGCHLD) ^
1003 ((options & WLINUXCLONE) != 0)) {
1008 if (siginfo != NULL) {
1009 bzero(siginfo, sizeof(*siginfo));
1010 siginfo->si_errno = 0;
1013 * SUSv4 requires that the si_signo value is always
1014 * SIGCHLD. Obey it despite the rfork(2) interface
1015 * allows to request other signal for child exit
1018 siginfo->si_signo = SIGCHLD;
1021 * This is still a rough estimate. We will fix the
1022 * cases TRAPPED, STOPPED, and CONTINUED later.
1024 if (WCOREDUMP(p->p_xsig)) {
1025 siginfo->si_code = CLD_DUMPED;
1026 siginfo->si_status = WTERMSIG(p->p_xsig);
1027 } else if (WIFSIGNALED(p->p_xsig)) {
1028 siginfo->si_code = CLD_KILLED;
1029 siginfo->si_status = WTERMSIG(p->p_xsig);
1031 siginfo->si_code = CLD_EXITED;
1032 siginfo->si_status = p->p_xexit;
1035 siginfo->si_pid = p->p_pid;
1036 siginfo->si_uid = p->p_ucred->cr_uid;
1039 * The si_addr field would be useful additional
1040 * detail, but apparently the PC value may be lost
1041 * when we reach this point. bzero() above sets
1042 * siginfo->si_addr to NULL.
1047 * There should be no reason to limit resources usage info to
1048 * exited processes only. A snapshot about any resources used
1049 * by a stopped process may be exactly what is needed.
1051 if (wrusage != NULL) {
1052 rup = &wrusage->wru_self;
1055 calcru(p, &rup->ru_utime, &rup->ru_stime);
1058 rup = &wrusage->wru_children;
1059 *rup = p->p_stats->p_cru;
1060 calccru(p, &rup->ru_utime, &rup->ru_stime);
1063 if (p->p_state == PRS_ZOMBIE && !check_only) {
1065 proc_reap(td, p, status, options);
1072 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1073 struct rusage *rusage)
1075 struct __wrusage wru, *wrup;
1081 * Translate the special pid values into the (idtype, pid)
1082 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1083 * kern_wait6() on its own.
1085 if (pid == WAIT_ANY) {
1088 } else if (pid < 0) {
1102 * For backward compatibility we implicitly add flags WEXITED
1103 * and WTRAPPED here.
1105 options |= WEXITED | WTRAPPED;
1106 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1108 *rusage = wru.wru_self;
1113 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1114 int *status, int options, int si_code)
1118 PROC_LOCK_ASSERT(p, MA_OWNED);
1119 sx_assert(&proctree_lock, SA_XLOCKED);
1120 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1121 si_code == CLD_CONTINUED);
1123 cont = si_code == CLD_CONTINUED;
1124 if ((options & WNOWAIT) == 0) {
1126 p->p_flag &= ~P_CONTINUED;
1128 p->p_flag |= P_WAITED;
1129 PROC_LOCK(td->td_proc);
1130 sigqueue_take(p->p_ksi);
1131 PROC_UNLOCK(td->td_proc);
1133 sx_xunlock(&proctree_lock);
1134 if (siginfo != NULL) {
1135 siginfo->si_code = si_code;
1136 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1139 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1141 td->td_retval[0] = p->p_pid;
1145 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1146 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1150 int error, nfound, ret;
1152 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1153 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1154 AUDIT_ARG_VALUE(options);
1158 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1160 id = (id_t)q->p_pgid;
1165 /* If we don't know the option, just return. */
1166 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1167 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1169 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1171 * We will be unable to find any matching processes,
1172 * because there are no known events to look for.
1173 * Prefer to return error instead of blocking
1180 if (q->p_flag & P_STATCHILD) {
1182 q->p_flag &= ~P_STATCHILD;
1186 sx_xlock(&proctree_lock);
1187 LIST_FOREACH(p, &q->p_children, p_sibling) {
1189 ret = proc_to_reap(td, p, idtype, id, status, options,
1190 wrusage, siginfo, 0);
1196 td->td_retval[0] = pid;
1200 PROC_LOCK_ASSERT(p, MA_OWNED);
1202 if ((options & (WTRAPPED | WUNTRACED)) != 0)
1205 if ((options & WTRAPPED) != 0 &&
1206 (p->p_flag & P_TRACED) != 0 &&
1207 (p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) != 0 &&
1208 p->p_suspcount == p->p_numthreads &&
1209 (p->p_flag & P_WAITED) == 0) {
1212 "wait: returning trapped pid %d status %#x "
1213 "(xstat %d) xthread %d",
1214 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1215 p->p_xthread != NULL ?
1216 p->p_xthread->td_tid : -1);
1217 report_alive_proc(td, p, siginfo, status, options,
1221 if ((options & WUNTRACED) != 0 &&
1222 (p->p_flag & P_STOPPED_SIG) != 0 &&
1223 p->p_suspcount == p->p_numthreads &&
1224 (p->p_flag & P_WAITED) == 0) {
1226 report_alive_proc(td, p, siginfo, status, options,
1230 if ((options & (WTRAPPED | WUNTRACED)) != 0)
1232 if ((options & WCONTINUED) != 0 &&
1233 (p->p_flag & P_CONTINUED) != 0) {
1234 report_alive_proc(td, p, siginfo, status, options,
1242 * Look in the orphans list too, to allow the parent to
1243 * collect it's child exit status even if child is being
1246 * Debugger detaches from the parent upon successful
1247 * switch-over from parent to child. At this point due to
1248 * re-parenting the parent loses the child to debugger and a
1249 * wait4(2) call would report that it has no children to wait
1250 * for. By maintaining a list of orphans we allow the parent
1251 * to successfully wait until the child becomes a zombie.
1254 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1255 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1258 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1259 (int)td->td_retval[0]));
1267 sx_xunlock(&proctree_lock);
1270 if (options & WNOHANG) {
1271 sx_xunlock(&proctree_lock);
1272 td->td_retval[0] = 0;
1276 sx_xunlock(&proctree_lock);
1277 if (q->p_flag & P_STATCHILD) {
1278 q->p_flag &= ~P_STATCHILD;
1281 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
1289 * Make process 'parent' the new parent of process 'child'.
1290 * Must be called with an exclusive hold of proctree lock.
1293 proc_reparent(struct proc *child, struct proc *parent)
1296 sx_assert(&proctree_lock, SX_XLOCKED);
1297 PROC_LOCK_ASSERT(child, MA_OWNED);
1298 if (child->p_pptr == parent)
1301 PROC_LOCK(child->p_pptr);
1302 sigqueue_take(child->p_ksi);
1303 PROC_UNLOCK(child->p_pptr);
1304 LIST_REMOVE(child, p_sibling);
1305 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1307 clear_orphan(child);
1308 if (child->p_flag & P_TRACED) {
1309 if (LIST_EMPTY(&child->p_pptr->p_orphans)) {
1310 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1311 LIST_INSERT_HEAD(&child->p_pptr->p_orphans, child,
1314 LIST_INSERT_AFTER(LIST_FIRST(&child->p_pptr->p_orphans),
1317 child->p_treeflag |= P_TREE_ORPHANED;
1320 child->p_pptr = parent;