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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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>
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 -- death of process.
202 sys_sys_exit(struct thread *td, struct sys_exit_args *uap)
205 exit1(td, uap->rval, 0);
210 * Exit: deallocate address space and other resources, change proc state to
211 * zombie, and unlink proc from allproc and parent's lists. Save exit status
212 * and rusage for wait(). Check for child processes and orphan them.
215 exit1(struct thread *td, int rval, int signo)
217 struct proc *p, *nq, *q, *t;
219 ksiginfo_t *ksi, *ksi1;
222 mtx_assert(&Giant, MA_NOTOWNED);
223 KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));
227 * XXX in case we're rebooting we just let init die in order to
228 * work around an unsolved stack overflow seen very late during
229 * shutdown on sparc64 when the gmirror worker process exists.
230 * XXX what to do now that sparc64 is gone... remove if?
232 if (p == initproc && rebooting == 0) {
233 printf("init died (signal %d, exit %d)\n", signo, rval);
234 panic("Going nowhere without my init!");
238 * Deref SU mp, since the thread does not return to userspace.
240 td_softdep_cleanup(td);
243 * MUST abort all other threads before proceeding past here.
247 * First check if some other thread or external request got
248 * here before us. If so, act appropriately: exit or suspend.
249 * We must ensure that stop requests are handled before we set
252 thread_suspend_check(0);
253 while (p->p_flag & P_HADTHREADS) {
255 * Kill off the other threads. This requires
256 * some co-operation from other parts of the kernel
257 * so it may not be instantaneous. With this state set
258 * any thread entering the kernel from userspace will
259 * thread_exit() in trap(). Any thread attempting to
260 * sleep will return immediately with EINTR or EWOULDBLOCK
261 * which will hopefully force them to back out to userland
262 * freeing resources as they go. Any thread attempting
263 * to return to userland will thread_exit() from userret().
264 * thread_exit() will unsuspend us when the last of the
265 * other threads exits.
266 * If there is already a thread singler after resumption,
267 * calling thread_single will fail; in that case, we just
268 * re-check all suspension request, the thread should
269 * either be suspended there or exit.
271 if (!thread_single(p, SINGLE_EXIT))
273 * All other activity in this process is now
274 * stopped. Threading support has been turned
279 * Recheck for new stop or suspend requests which
280 * might appear while process lock was dropped in
283 thread_suspend_check(0);
285 KASSERT(p->p_numthreads == 1,
286 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
287 racct_sub(p, RACCT_NTHR, 1);
289 /* Let event handler change exit status */
294 * Ignore any pending request to stop due to a stop signal.
295 * Once P_WEXIT is set, future requests will be ignored as
298 p->p_flag &= ~P_STOPPED_SIG;
299 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
301 /* Note that we are exiting. */
302 p->p_flag |= P_WEXIT;
305 * Wait for any processes that have a hold on our vmspace to
306 * release their reference.
308 while (p->p_lock > 0)
309 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
312 /* Drain the limit callout while we don't have the proc locked */
313 callout_drain(&p->p_limco);
317 * The Sun BSM exit token contains two components: an exit status as
318 * passed to exit(), and a return value to indicate what sort of exit
319 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
320 * what the return value is.
322 AUDIT_ARG_EXIT(rval, 0);
323 AUDIT_SYSCALL_EXIT(0, td);
326 /* Are we a task leader with peers? */
327 if (p->p_peers != NULL && p == p->p_leader) {
328 mtx_lock(&ppeers_lock);
332 kern_psignal(q, SIGKILL);
336 while (p->p_peers != NULL)
337 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
338 mtx_unlock(&ppeers_lock);
343 if (p->p_sysent->sv_onexit != NULL)
344 p->p_sysent->sv_onexit(p);
347 * Check if any loadable modules need anything done at process exit.
348 * E.g. SYSV IPC stuff.
349 * Event handler could change exit status.
350 * XXX what if one of these generates an error?
352 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
355 * If parent is waiting for us to exit or exec,
356 * P_PPWAIT is set; we will wakeup the parent below.
363 * Stop the real interval timer. If the handler is currently
364 * executing, prevent it from rearming itself and let it finish.
366 if (timevalisset(&p->p_realtimer.it_value) &&
367 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
368 timevalclear(&p->p_realtimer.it_interval);
369 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
370 KASSERT(!timevalisset(&p->p_realtimer.it_value),
371 ("realtime timer is still armed"));
376 umtx_thread_exit(td);
380 * Reset any sigio structures pointing to us as a result of
381 * F_SETOWN with our pid. The P_WEXIT flag interlocks with fsetown().
383 funsetownlst(&p->p_sigiolst);
386 * Close open files and release open-file table.
393 * If this thread tickled GEOM, we need to wait for the giggling to
394 * stop before we return to userland
396 if (td->td_pflags & TDP_GEOM)
400 * Remove ourself from our leader's peer list and wake our leader.
402 if (p->p_leader->p_peers != NULL) {
403 mtx_lock(&ppeers_lock);
404 if (p->p_leader->p_peers != NULL) {
406 while (q->p_peers != p)
408 q->p_peers = p->p_peers;
411 mtx_unlock(&ppeers_lock);
415 (void)acct_process(td);
421 * Release reference to text vnode
423 if (p->p_textvp != NULL) {
429 * Release our limits structure.
431 lim_free(p->p_limit);
437 * Call machine-dependent code to release any
438 * machine-dependent resources other than the address space.
439 * The address space is released by "vmspace_exitfree(p)" in
444 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
447 * Remove from allproc. It still sits in the hash.
449 sx_xlock(&allproc_lock);
450 LIST_REMOVE(p, p_list);
454 * Used by ddb's 'ps' command to find this process via the
457 p->p_list.le_prev = NULL;
459 sx_xunlock(&allproc_lock);
461 sx_xlock(&proctree_lock);
463 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
467 * killjobc() might drop and re-acquire proctree_lock to
468 * revoke control tty if exiting process was a session leader.
473 * Reparent all children processes:
474 * - traced ones to the original parent (or init if we are that parent)
477 q = LIST_FIRST(&p->p_children);
478 if (q != NULL) /* only need this if any child is S_ZOMB */
480 for (; q != NULL; q = nq) {
481 nq = LIST_NEXT(q, p_sibling);
482 ksi = ksiginfo_alloc(TRUE);
484 q->p_sigparent = SIGCHLD;
486 if ((q->p_flag & P_TRACED) == 0) {
487 proc_reparent(q, q->p_reaper, true);
488 if (q->p_state == PRS_ZOMBIE) {
490 * Inform reaper about the reparented
491 * zombie, since wait(2) has something
492 * new to report. Guarantee queueing
493 * of the SIGCHLD signal, similar to
494 * the _exit() behaviour, by providing
495 * our ksiginfo. Ksi is freed by the
498 if (q->p_ksi == NULL) {
501 ksiginfo_copy(q->p_ksi, ksi);
502 ksi->ksi_flags |= KSI_INS;
506 PROC_LOCK(q->p_reaper);
507 pksignal(q->p_reaper, SIGCHLD, ksi1);
508 PROC_UNLOCK(q->p_reaper);
509 } else if (q->p_pdeathsig > 0) {
511 * The child asked to received a signal
514 kern_psignal(q, q->p_pdeathsig);
518 * Traced processes are killed by default
519 * since their existence means someone is
522 t = proc_realparent(q);
524 proc_reparent(q, q->p_reaper, true);
527 proc_reparent(q, t, true);
531 * Since q was found on our children list, the
532 * proc_reparent() call moved q to the orphan
533 * list due to present P_TRACED flag. Clear
534 * orphan link for q now while q is locked.
536 proc_clear_orphan(q);
537 q->p_flag &= ~P_TRACED;
538 q->p_flag2 &= ~P2_PTRACE_FSTP;
541 FOREACH_THREAD_IN_PROC(q, tdt) {
542 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
546 if (kern_kill_on_dbg_exit) {
547 q->p_flag &= ~P_STOPPED_TRACE;
548 kern_psignal(q, SIGKILL);
549 } else if ((q->p_flag & (P_STOPPED_TRACE |
550 P_STOPPED_SIG)) != 0) {
551 sigqueue_delete_proc(q, SIGTRAP);
561 * Also get rid of our orphans.
563 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
565 KASSERT(q->p_oppid == p->p_pid,
566 ("orphan %p of %p has unexpected oppid %d", q, p,
568 q->p_oppid = q->p_reaper->p_pid;
571 * If we are the real parent of this process
572 * but it has been reparented to a debugger, then
573 * check if it asked for a signal when we exit.
575 if (q->p_pdeathsig > 0)
576 kern_psignal(q, q->p_pdeathsig);
577 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
579 proc_clear_orphan(q);
584 if (SDT_PROBES_ENABLED()) {
585 int reason = CLD_EXITED;
586 if (WCOREDUMP(signo))
588 else if (WIFSIGNALED(signo))
590 SDT_PROBE1(proc, , , exit, reason);
594 /* Save exit status. */
598 if (p->p_sysent->sv_ontdexit != NULL)
599 p->p_sysent->sv_ontdexit(td);
603 * Tell the DTrace fasttrap provider about the exit if it
604 * has declared an interest.
606 if (dtrace_fasttrap_exit)
607 dtrace_fasttrap_exit(p);
611 * Notify interested parties of our demise.
613 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
616 * If this is a process with a descriptor, we may not need to deliver
617 * a signal to the parent. proctree_lock is held over
618 * procdesc_exit() to serialize concurrent calls to close() and
622 if (p->p_procdesc == NULL || procdesc_exit(p)) {
624 * Notify parent that we're gone. If parent has the
625 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
626 * notify process 1 instead (and hope it will handle this
629 PROC_LOCK(p->p_pptr);
630 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
631 if (p->p_pptr->p_sigacts->ps_flag &
632 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
635 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
638 proc_reparent(p, p->p_reaper, true);
639 p->p_sigparent = SIGCHLD;
640 PROC_LOCK(p->p_pptr);
643 * Notify parent, so in case he was wait(2)ing or
644 * executing waitpid(2) with our pid, he will
649 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
651 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
653 } else if (p->p_sigparent != 0) {
654 if (p->p_sigparent == SIGCHLD) {
656 } else { /* LINUX thread */
661 PROC_LOCK(p->p_pptr);
662 sx_xunlock(&proctree_lock);
664 if (signal_parent == 1) {
666 } else if (signal_parent == 2) {
667 kern_psignal(p->p_pptr, p->p_sigparent);
670 /* Tell the prison that we are gone. */
671 prison_proc_free(p->p_ucred->cr_prison);
674 * The state PRS_ZOMBIE prevents other proesses from sending
675 * signal to the process, to avoid memory leak, we free memory
676 * for signal queue at the time when the state is set.
678 sigqueue_flush(&p->p_sigqueue);
679 sigqueue_flush(&td->td_sigqueue);
682 * We have to wait until after acquiring all locks before
683 * changing p_state. We need to avoid all possible context
684 * switches (including ones from blocking on a mutex) while
685 * marked as a zombie. We also have to set the zombie state
686 * before we release the parent process' proc lock to avoid
687 * a lost wakeup. So, we first call wakeup, then we grab the
688 * sched lock, update the state, and release the parent process'
692 cv_broadcast(&p->p_pwait);
693 sched_exit(p->p_pptr, td);
695 p->p_state = PRS_ZOMBIE;
696 PROC_UNLOCK(p->p_pptr);
699 * Save our children's rusage information in our exit rusage.
702 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
706 * Make sure the scheduler takes this thread out of its tables etc.
707 * This will also release this thread's reference to the ucred.
708 * Other thread parts to release include pcb bits and such.
713 #ifndef _SYS_SYSPROTO_H_
722 sys_abort2(struct thread *td, struct abort2_args *uap)
724 struct proc *p = td->td_proc;
730 * Do it right now so we can log either proper call of abort2(), or
731 * note, that invalid argument was passed. 512 is big enough to
732 * handle 16 arguments' descriptions with additional comments.
734 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
736 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
737 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
739 * Since we can't return from abort2(), send SIGKILL in cases, where
740 * abort2() was called improperly
743 /* Prevent from DoSes from user-space. */
744 if (uap->nargs < 0 || uap->nargs > 16)
746 if (uap->nargs > 0) {
747 if (uap->args == NULL)
749 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
754 * Limit size of 'reason' string to 128. Will fit even when
755 * maximal number of arguments was chosen to be logged.
757 if (uap->why != NULL) {
758 error = sbuf_copyin(sb, uap->why, 128);
762 sbuf_printf(sb, "(null)");
764 if (uap->nargs > 0) {
765 sbuf_printf(sb, "(");
766 for (i = 0;i < uap->nargs; i++)
767 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
768 sbuf_printf(sb, ")");
771 * Final stage: arguments were proper, string has been
772 * successfully copied from userspace, and copying pointers
773 * from user-space succeed.
777 if (sig == SIGKILL) {
779 sbuf_printf(sb, " (Reason text inaccessible)");
783 log(LOG_INFO, "%s", sbuf_data(sb));
791 * The dirty work is handled by kern_wait().
794 owait(struct thread *td, struct owait_args *uap __unused)
798 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
800 td->td_retval[1] = status;
803 #endif /* COMPAT_43 */
806 * The dirty work is handled by kern_wait().
809 sys_wait4(struct thread *td, struct wait4_args *uap)
811 struct rusage ru, *rup;
814 if (uap->rusage != NULL)
818 error = kern_wait(td, uap->pid, &status, uap->options, rup);
819 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
820 error = copyout(&status, uap->status, sizeof(status));
821 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
822 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
827 sys_wait6(struct thread *td, struct wait6_args *uap)
829 struct __wrusage wru, *wrup;
835 idtype = uap->idtype;
838 if (uap->wrusage != NULL)
843 if (uap->info != NULL) {
845 bzero(sip, sizeof(*sip));
850 * We expect all callers of wait6() to know about WEXITED and
853 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
855 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
856 error = copyout(&status, uap->status, sizeof(status));
857 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
858 error = copyout(&wru, uap->wrusage, sizeof(wru));
859 if (uap->info != NULL && error == 0)
860 error = copyout(&si, uap->info, sizeof(si));
865 * Reap the remains of a zombie process and optionally return status and
866 * rusage. Asserts and will release both the proctree_lock and the process
867 * lock as part of its work.
870 proc_reap(struct thread *td, struct proc *p, int *status, int options)
874 sx_assert(&proctree_lock, SA_XLOCKED);
875 PROC_LOCK_ASSERT(p, MA_OWNED);
876 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
878 mtx_spin_wait_unlocked(&p->p_slock);
883 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
884 if (options & WNOWAIT) {
886 * Only poll, returning the status. Caller does not wish to
887 * release the proc struct just yet.
890 sx_xunlock(&proctree_lock);
895 sigqueue_take(p->p_ksi);
899 * If we got the child via a ptrace 'attach', we need to give it back
902 if (p->p_oppid != p->p_pptr->p_pid) {
904 t = proc_realparent(p);
908 "wait: traced child %d moved back to parent %d", p->p_pid,
910 proc_reparent(p, t, false);
912 pksignal(t, SIGCHLD, p->p_ksi);
914 cv_broadcast(&p->p_pwait);
916 sx_xunlock(&proctree_lock);
922 * Remove other references to this process to ensure we have an
923 * exclusive reference.
925 sx_xlock(PIDHASHLOCK(p->p_pid));
926 LIST_REMOVE(p, p_hash);
927 sx_xunlock(PIDHASHLOCK(p->p_pid));
928 LIST_REMOVE(p, p_sibling);
929 reaper_abandon_children(p, true);
932 proc_clear_orphan(p);
935 if (p->p_procdesc != NULL)
937 sx_xunlock(&proctree_lock);
939 proc_id_clear(PROC_ID_PID, p->p_pid);
942 knlist_detach(p->p_klist);
947 * Removal from allproc list and process group list paired with
948 * PROC_LOCK which was executed during that time should guarantee
949 * nothing can reach this process anymore. As such further locking
952 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
955 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
959 * Decrement the count of procs running with this uid.
961 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
964 * Destroy resource accounting information associated with the process.
969 racct_sub(p, RACCT_NPROC, 1);
976 * Free credentials, arguments, and sigacts.
979 pargs_drop(p->p_args);
981 sigacts_free(p->p_sigacts);
985 * Do any thread-system specific cleanups.
990 * Give vm and machine-dependent layer a chance to free anything that
991 * cpu_exit couldn't release while still running in process context.
998 KASSERT(FIRST_THREAD_IN_PROC(p),
999 ("proc_reap: no residual thread!"));
1000 uma_zfree(proc_zone, p);
1001 atomic_add_int(&nprocs, -1);
1005 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1006 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1011 sx_assert(&proctree_lock, SA_XLOCKED);
1017 if (p->p_procdesc == NULL ||
1018 (p->p_pptr == td->td_proc &&
1019 (p->p_flag & P_TRACED) != 0)) {
1026 if (p->p_pid != (pid_t)id) {
1032 if (p->p_pgid != (pid_t)id) {
1038 if (p->p_session->s_sid != (pid_t)id) {
1044 if (p->p_ucred->cr_uid != (uid_t)id) {
1050 if (p->p_ucred->cr_gid != (gid_t)id) {
1056 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1062 * It seems that the thread structures get zeroed out
1063 * at process exit. This makes it impossible to
1064 * support P_SETID, P_CID or P_CPUID.
1071 if (p_canwait(td, p)) {
1076 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1082 * This special case handles a kthread spawned by linux_clone
1083 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1084 * functions need to be able to distinguish between waiting
1085 * on a process and waiting on a thread. It is a thread if
1086 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1087 * signifies we want to wait for threads and not processes.
1089 if ((p->p_sigparent != SIGCHLD) ^
1090 ((options & WLINUXCLONE) != 0)) {
1095 if (siginfo != NULL) {
1096 bzero(siginfo, sizeof(*siginfo));
1097 siginfo->si_errno = 0;
1100 * SUSv4 requires that the si_signo value is always
1101 * SIGCHLD. Obey it despite the rfork(2) interface
1102 * allows to request other signal for child exit
1105 siginfo->si_signo = SIGCHLD;
1108 * This is still a rough estimate. We will fix the
1109 * cases TRAPPED, STOPPED, and CONTINUED later.
1111 if (WCOREDUMP(p->p_xsig)) {
1112 siginfo->si_code = CLD_DUMPED;
1113 siginfo->si_status = WTERMSIG(p->p_xsig);
1114 } else if (WIFSIGNALED(p->p_xsig)) {
1115 siginfo->si_code = CLD_KILLED;
1116 siginfo->si_status = WTERMSIG(p->p_xsig);
1118 siginfo->si_code = CLD_EXITED;
1119 siginfo->si_status = p->p_xexit;
1122 siginfo->si_pid = p->p_pid;
1123 siginfo->si_uid = p->p_ucred->cr_uid;
1126 * The si_addr field would be useful additional
1127 * detail, but apparently the PC value may be lost
1128 * when we reach this point. bzero() above sets
1129 * siginfo->si_addr to NULL.
1134 * There should be no reason to limit resources usage info to
1135 * exited processes only. A snapshot about any resources used
1136 * by a stopped process may be exactly what is needed.
1138 if (wrusage != NULL) {
1139 rup = &wrusage->wru_self;
1142 calcru(p, &rup->ru_utime, &rup->ru_stime);
1145 rup = &wrusage->wru_children;
1146 *rup = p->p_stats->p_cru;
1147 calccru(p, &rup->ru_utime, &rup->ru_stime);
1150 if (p->p_state == PRS_ZOMBIE && !check_only) {
1151 proc_reap(td, p, status, options);
1158 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1159 struct rusage *rusage)
1161 struct __wrusage wru, *wrup;
1167 * Translate the special pid values into the (idtype, pid)
1168 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1169 * kern_wait6() on its own.
1171 if (pid == WAIT_ANY) {
1174 } else if (pid < 0) {
1188 * For backward compatibility we implicitly add flags WEXITED
1189 * and WTRAPPED here.
1191 options |= WEXITED | WTRAPPED;
1192 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1194 *rusage = wru.wru_self;
1199 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1200 int *status, int options, int si_code)
1204 PROC_LOCK_ASSERT(p, MA_OWNED);
1205 sx_assert(&proctree_lock, SA_XLOCKED);
1206 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1207 si_code == CLD_CONTINUED);
1209 cont = si_code == CLD_CONTINUED;
1210 if ((options & WNOWAIT) == 0) {
1212 p->p_flag &= ~P_CONTINUED;
1214 p->p_flag |= P_WAITED;
1215 if (kern_wait_dequeue_sigchld &&
1216 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1217 PROC_LOCK(td->td_proc);
1218 sigqueue_take(p->p_ksi);
1219 PROC_UNLOCK(td->td_proc);
1222 sx_xunlock(&proctree_lock);
1223 if (siginfo != NULL) {
1224 siginfo->si_code = si_code;
1225 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1228 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1230 td->td_retval[0] = p->p_pid;
1234 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1235 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1239 int error, nfound, ret;
1242 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1243 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1244 AUDIT_ARG_VALUE(options);
1248 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1250 id = (id_t)q->p_pgid;
1255 /* If we don't know the option, just return. */
1256 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1257 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1259 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1261 * We will be unable to find any matching processes,
1262 * because there are no known events to look for.
1263 * Prefer to return error instead of blocking
1270 if (q->p_flag & P_STATCHILD) {
1272 q->p_flag &= ~P_STATCHILD;
1275 sx_xlock(&proctree_lock);
1278 LIST_FOREACH(p, &q->p_children, p_sibling) {
1280 ret = proc_to_reap(td, p, idtype, id, status, options,
1281 wrusage, siginfo, 0);
1284 else if (ret != 1) {
1285 td->td_retval[0] = pid;
1290 PROC_LOCK_ASSERT(p, MA_OWNED);
1292 if ((options & WTRAPPED) != 0 &&
1293 (p->p_flag & P_TRACED) != 0) {
1296 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1297 p->p_suspcount == p->p_numthreads &&
1298 (p->p_flag & P_WAITED) == 0);
1302 "wait: returning trapped pid %d status %#x "
1303 "(xstat %d) xthread %d",
1304 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1305 p->p_xthread != NULL ?
1306 p->p_xthread->td_tid : -1);
1307 report_alive_proc(td, p, siginfo, status,
1308 options, CLD_TRAPPED);
1312 if ((options & WUNTRACED) != 0 &&
1313 (p->p_flag & P_STOPPED_SIG) != 0) {
1315 report = (p->p_suspcount == p->p_numthreads &&
1316 ((p->p_flag & P_WAITED) == 0));
1319 report_alive_proc(td, p, siginfo, status,
1320 options, CLD_STOPPED);
1324 if ((options & WCONTINUED) != 0 &&
1325 (p->p_flag & P_CONTINUED) != 0) {
1326 report_alive_proc(td, p, siginfo, status, options,
1334 * Look in the orphans list too, to allow the parent to
1335 * collect it's child exit status even if child is being
1338 * Debugger detaches from the parent upon successful
1339 * switch-over from parent to child. At this point due to
1340 * re-parenting the parent loses the child to debugger and a
1341 * wait4(2) call would report that it has no children to wait
1342 * for. By maintaining a list of orphans we allow the parent
1343 * to successfully wait until the child becomes a zombie.
1346 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1347 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1350 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1351 (int)td->td_retval[0]));
1359 sx_xunlock(&proctree_lock);
1362 if (options & WNOHANG) {
1363 sx_xunlock(&proctree_lock);
1364 td->td_retval[0] = 0;
1368 if (q->p_flag & P_STATCHILD) {
1369 q->p_flag &= ~P_STATCHILD;
1373 sx_xunlock(&proctree_lock);
1374 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1381 proc_add_orphan(struct proc *child, struct proc *parent)
1384 sx_assert(&proctree_lock, SX_XLOCKED);
1385 KASSERT((child->p_flag & P_TRACED) != 0,
1386 ("proc_add_orphan: not traced"));
1388 if (LIST_EMPTY(&parent->p_orphans)) {
1389 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1390 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1392 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1395 child->p_treeflag |= P_TREE_ORPHANED;
1399 * Make process 'parent' the new parent of process 'child'.
1400 * Must be called with an exclusive hold of proctree lock.
1403 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1406 sx_assert(&proctree_lock, SX_XLOCKED);
1407 PROC_LOCK_ASSERT(child, MA_OWNED);
1408 if (child->p_pptr == parent)
1411 PROC_LOCK(child->p_pptr);
1412 sigqueue_take(child->p_ksi);
1413 PROC_UNLOCK(child->p_pptr);
1414 LIST_REMOVE(child, p_sibling);
1415 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1417 proc_clear_orphan(child);
1418 if ((child->p_flag & P_TRACED) != 0) {
1419 proc_add_orphan(child, child->p_pptr);
1422 child->p_pptr = parent;
1424 child->p_oppid = parent->p_pid;