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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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_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_sys_exit(struct thread *td, struct sys_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));
234 * XXX in case we're rebooting we just let init die in order to
235 * work around an unsolved stack overflow seen very late during
236 * shutdown on sparc64 when the gmirror worker process exists.
237 * XXX what to do now that sparc64 is gone... remove if?
239 if (p == initproc && rebooting == 0) {
240 printf("init died (signal %d, exit %d)\n", signo, rval);
241 panic("Going nowhere without my init!");
245 * Deref SU mp, since the thread does not return to userspace.
247 td_softdep_cleanup(td);
250 * MUST abort all other threads before proceeding past here.
254 * First check if some other thread or external request got
255 * here before us. If so, act appropriately: exit or suspend.
256 * We must ensure that stop requests are handled before we set
259 thread_suspend_check(0);
260 while (p->p_flag & P_HADTHREADS) {
262 * Kill off the other threads. This requires
263 * some co-operation from other parts of the kernel
264 * so it may not be instantaneous. With this state set
265 * any thread entering the kernel from userspace will
266 * thread_exit() in trap(). Any thread attempting to
267 * sleep will return immediately with EINTR or EWOULDBLOCK
268 * which will hopefully force them to back out to userland
269 * freeing resources as they go. Any thread attempting
270 * to return to userland will thread_exit() from userret().
271 * thread_exit() will unsuspend us when the last of the
272 * other threads exits.
273 * If there is already a thread singler after resumption,
274 * calling thread_single will fail; in that case, we just
275 * re-check all suspension request, the thread should
276 * either be suspended there or exit.
278 if (!thread_single(p, SINGLE_EXIT))
280 * All other activity in this process is now
281 * stopped. Threading support has been turned
286 * Recheck for new stop or suspend requests which
287 * might appear while process lock was dropped in
290 thread_suspend_check(0);
292 KASSERT(p->p_numthreads == 1,
293 ("exit1: proc %p exiting with %d threads", p, p->p_numthreads));
294 racct_sub(p, RACCT_NTHR, 1);
296 /* Let event handler change exit status */
301 * Ignore any pending request to stop due to a stop signal.
302 * Once P_WEXIT is set, future requests will be ignored as
305 p->p_flag &= ~P_STOPPED_SIG;
306 KASSERT(!P_SHOULDSTOP(p), ("exiting process is stopped"));
308 /* Note that we are exiting. */
309 p->p_flag |= P_WEXIT;
312 * Wait for any processes that have a hold on our vmspace to
313 * release their reference.
315 while (p->p_lock > 0)
316 msleep(&p->p_lock, &p->p_mtx, PWAIT, "exithold", 0);
319 /* Drain the limit callout while we don't have the proc locked */
320 callout_drain(&p->p_limco);
324 * The Sun BSM exit token contains two components: an exit status as
325 * passed to exit(), and a return value to indicate what sort of exit
326 * it was. The exit status is WEXITSTATUS(rv), but it's not clear
327 * what the return value is.
329 AUDIT_ARG_EXIT(rval, 0);
330 AUDIT_SYSCALL_EXIT(0, td);
333 /* Are we a task leader with peers? */
334 if (p->p_peers != NULL && p == p->p_leader) {
335 mtx_lock(&ppeers_lock);
339 kern_psignal(q, SIGKILL);
343 while (p->p_peers != NULL)
344 msleep(p, &ppeers_lock, PWAIT, "exit1", 0);
345 mtx_unlock(&ppeers_lock);
351 * Check if any loadable modules need anything done at process exit.
352 * E.g. SYSV IPC stuff.
353 * Event handler could change exit status.
354 * XXX what if one of these generates an error?
356 EVENTHANDLER_DIRECT_INVOKE(process_exit, p);
359 * If parent is waiting for us to exit or exec,
360 * P_PPWAIT is set; we will wakeup the parent below.
367 * Stop the real interval timer. If the handler is currently
368 * executing, prevent it from rearming itself and let it finish.
370 if (timevalisset(&p->p_realtimer.it_value) &&
371 _callout_stop_safe(&p->p_itcallout, CS_EXECUTING, NULL) == 0) {
372 timevalclear(&p->p_realtimer.it_interval);
373 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0);
374 KASSERT(!timevalisset(&p->p_realtimer.it_value),
375 ("realtime timer is still armed"));
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);
420 (void)acct_process(td);
426 * Release reference to text vnode
428 if (p->p_textvp != NULL) {
434 * Release our limits structure.
436 lim_free(p->p_limit);
442 * Call machine-dependent code to release any
443 * machine-dependent resources other than the address space.
444 * The address space is released by "vmspace_exitfree(p)" in
449 WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid);
452 * Remove from allproc. It still sits in the hash.
454 sx_xlock(&allproc_lock);
455 LIST_REMOVE(p, p_list);
459 * Used by ddb's 'ps' command to find this process via the
462 p->p_list.le_prev = NULL;
464 sx_xunlock(&allproc_lock);
466 sx_xlock(&proctree_lock);
468 p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
472 * killjobc() might drop and re-acquire proctree_lock to
473 * revoke control tty if exiting process was a session leader.
478 * Reparent all children processes:
479 * - traced ones to the original parent (or init if we are that parent)
482 q = LIST_FIRST(&p->p_children);
483 if (q != NULL) /* only need this if any child is S_ZOMB */
485 for (; q != NULL; q = nq) {
486 nq = LIST_NEXT(q, p_sibling);
487 ksi = ksiginfo_alloc(TRUE);
489 q->p_sigparent = SIGCHLD;
491 if ((q->p_flag & P_TRACED) == 0) {
492 proc_reparent(q, q->p_reaper, true);
493 if (q->p_state == PRS_ZOMBIE) {
495 * Inform reaper about the reparented
496 * zombie, since wait(2) has something
497 * new to report. Guarantee queueing
498 * of the SIGCHLD signal, similar to
499 * the _exit() behaviour, by providing
500 * our ksiginfo. Ksi is freed by the
503 if (q->p_ksi == NULL) {
506 ksiginfo_copy(q->p_ksi, ksi);
507 ksi->ksi_flags |= KSI_INS;
511 PROC_LOCK(q->p_reaper);
512 pksignal(q->p_reaper, SIGCHLD, ksi1);
513 PROC_UNLOCK(q->p_reaper);
514 } else if (q->p_pdeathsig > 0) {
516 * The child asked to received a signal
519 kern_psignal(q, q->p_pdeathsig);
523 * Traced processes are killed by default
524 * since their existence means someone is
527 t = proc_realparent(q);
529 proc_reparent(q, q->p_reaper, true);
532 proc_reparent(q, t, true);
536 * Since q was found on our children list, the
537 * proc_reparent() call moved q to the orphan
538 * list due to present P_TRACED flag. Clear
539 * orphan link for q now while q is locked.
541 proc_clear_orphan(q);
542 q->p_flag &= ~P_TRACED;
543 q->p_flag2 &= ~P2_PTRACE_FSTP;
546 FOREACH_THREAD_IN_PROC(q, tdt) {
547 tdt->td_dbgflags &= ~(TDB_SUSPEND | TDB_XSIG |
551 if (kern_kill_on_dbg_exit) {
552 q->p_flag &= ~P_STOPPED_TRACE;
553 kern_psignal(q, SIGKILL);
554 } else if ((q->p_flag & (P_STOPPED_TRACE |
555 P_STOPPED_SIG)) != 0) {
556 sigqueue_delete_proc(q, SIGTRAP);
566 * Also get rid of our orphans.
568 while ((q = LIST_FIRST(&p->p_orphans)) != NULL) {
570 KASSERT(q->p_oppid == p->p_pid,
571 ("orphan %p of %p has unexpected oppid %d", q, p,
573 q->p_oppid = q->p_reaper->p_pid;
576 * If we are the real parent of this process
577 * but it has been reparented to a debugger, then
578 * check if it asked for a signal when we exit.
580 if (q->p_pdeathsig > 0)
581 kern_psignal(q, q->p_pdeathsig);
582 CTR2(KTR_PTRACE, "exit: pid %d, clearing orphan %d", p->p_pid,
584 proc_clear_orphan(q);
589 if (SDT_PROBES_ENABLED()) {
590 int reason = CLD_EXITED;
591 if (WCOREDUMP(signo))
593 else if (WIFSIGNALED(signo))
595 SDT_PROBE1(proc, , , exit, reason);
599 /* Save exit status. */
603 if (p->p_sysent->sv_ontdexit != NULL)
604 p->p_sysent->sv_ontdexit(td);
608 * Tell the DTrace fasttrap provider about the exit if it
609 * has declared an interest.
611 if (dtrace_fasttrap_exit)
612 dtrace_fasttrap_exit(p);
616 * Notify interested parties of our demise.
618 KNOTE_LOCKED(p->p_klist, NOTE_EXIT);
621 * If this is a process with a descriptor, we may not need to deliver
622 * a signal to the parent. proctree_lock is held over
623 * procdesc_exit() to serialize concurrent calls to close() and
627 if (p->p_procdesc == NULL || procdesc_exit(p)) {
629 * Notify parent that we're gone. If parent has the
630 * PS_NOCLDWAIT flag set, or if the handler is set to SIG_IGN,
631 * notify process 1 instead (and hope it will handle this
634 PROC_LOCK(p->p_pptr);
635 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx);
636 if (p->p_pptr->p_sigacts->ps_flag &
637 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
640 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
643 proc_reparent(p, p->p_reaper, true);
644 p->p_sigparent = SIGCHLD;
645 PROC_LOCK(p->p_pptr);
648 * Notify parent, so in case he was wait(2)ing or
649 * executing waitpid(2) with our pid, he will
654 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx);
656 if (p->p_pptr == p->p_reaper || p->p_pptr == initproc) {
658 } else if (p->p_sigparent != 0) {
659 if (p->p_sigparent == SIGCHLD) {
661 } else { /* LINUX thread */
666 PROC_LOCK(p->p_pptr);
667 sx_xunlock(&proctree_lock);
669 if (signal_parent == 1) {
671 } else if (signal_parent == 2) {
672 kern_psignal(p->p_pptr, p->p_sigparent);
675 /* Tell the prison that we are gone. */
676 prison_proc_free(p->p_ucred->cr_prison);
679 * The state PRS_ZOMBIE prevents other proesses from sending
680 * signal to the process, to avoid memory leak, we free memory
681 * for signal queue at the time when the state is set.
683 sigqueue_flush(&p->p_sigqueue);
684 sigqueue_flush(&td->td_sigqueue);
687 * We have to wait until after acquiring all locks before
688 * changing p_state. We need to avoid all possible context
689 * switches (including ones from blocking on a mutex) while
690 * marked as a zombie. We also have to set the zombie state
691 * before we release the parent process' proc lock to avoid
692 * a lost wakeup. So, we first call wakeup, then we grab the
693 * sched lock, update the state, and release the parent process'
697 cv_broadcast(&p->p_pwait);
698 sched_exit(p->p_pptr, td);
700 p->p_state = PRS_ZOMBIE;
701 PROC_UNLOCK(p->p_pptr);
704 * Save our children's rusage information in our exit rusage.
707 ruadd(&p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
711 * Make sure the scheduler takes this thread out of its tables etc.
712 * This will also release this thread's reference to the ucred.
713 * Other thread parts to release include pcb bits and such.
718 #ifndef _SYS_SYSPROTO_H_
727 sys_abort2(struct thread *td, struct abort2_args *uap)
729 struct proc *p = td->td_proc;
735 * Do it right now so we can log either proper call of abort2(), or
736 * note, that invalid argument was passed. 512 is big enough to
737 * handle 16 arguments' descriptions with additional comments.
739 sb = sbuf_new(NULL, NULL, 512, SBUF_FIXEDLEN);
741 sbuf_printf(sb, "%s(pid %d uid %d) aborted: ",
742 p->p_comm, p->p_pid, td->td_ucred->cr_uid);
744 * Since we can't return from abort2(), send SIGKILL in cases, where
745 * abort2() was called improperly
748 /* Prevent from DoSes from user-space. */
749 if (uap->nargs < 0 || uap->nargs > 16)
751 if (uap->nargs > 0) {
752 if (uap->args == NULL)
754 error = copyin(uap->args, uargs, uap->nargs * sizeof(void *));
759 * Limit size of 'reason' string to 128. Will fit even when
760 * maximal number of arguments was chosen to be logged.
762 if (uap->why != NULL) {
763 error = sbuf_copyin(sb, uap->why, 128);
767 sbuf_printf(sb, "(null)");
769 if (uap->nargs > 0) {
770 sbuf_printf(sb, "(");
771 for (i = 0;i < uap->nargs; i++)
772 sbuf_printf(sb, "%s%p", i == 0 ? "" : ", ", uargs[i]);
773 sbuf_printf(sb, ")");
776 * Final stage: arguments were proper, string has been
777 * successfully copied from userspace, and copying pointers
778 * from user-space succeed.
782 if (sig == SIGKILL) {
784 sbuf_printf(sb, " (Reason text inaccessible)");
788 log(LOG_INFO, "%s", sbuf_data(sb));
796 * The dirty work is handled by kern_wait().
799 owait(struct thread *td, struct owait_args *uap __unused)
803 error = kern_wait(td, WAIT_ANY, &status, 0, NULL);
805 td->td_retval[1] = status;
808 #endif /* COMPAT_43 */
811 * The dirty work is handled by kern_wait().
814 sys_wait4(struct thread *td, struct wait4_args *uap)
816 struct rusage ru, *rup;
819 if (uap->rusage != NULL)
823 error = kern_wait(td, uap->pid, &status, uap->options, rup);
824 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
825 error = copyout(&status, uap->status, sizeof(status));
826 if (uap->rusage != NULL && error == 0 && td->td_retval[0] != 0)
827 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
832 sys_wait6(struct thread *td, struct wait6_args *uap)
834 struct __wrusage wru, *wrup;
840 idtype = uap->idtype;
843 if (uap->wrusage != NULL)
848 if (uap->info != NULL) {
850 bzero(sip, sizeof(*sip));
855 * We expect all callers of wait6() to know about WEXITED and
858 error = kern_wait6(td, idtype, id, &status, uap->options, wrup, sip);
860 if (uap->status != NULL && error == 0 && td->td_retval[0] != 0)
861 error = copyout(&status, uap->status, sizeof(status));
862 if (uap->wrusage != NULL && error == 0 && td->td_retval[0] != 0)
863 error = copyout(&wru, uap->wrusage, sizeof(wru));
864 if (uap->info != NULL && error == 0)
865 error = copyout(&si, uap->info, sizeof(si));
870 * Reap the remains of a zombie process and optionally return status and
871 * rusage. Asserts and will release both the proctree_lock and the process
872 * lock as part of its work.
875 proc_reap(struct thread *td, struct proc *p, int *status, int options)
879 sx_assert(&proctree_lock, SA_XLOCKED);
880 PROC_LOCK_ASSERT(p, MA_OWNED);
881 KASSERT(p->p_state == PRS_ZOMBIE, ("proc_reap: !PRS_ZOMBIE"));
883 mtx_spin_wait_unlocked(&p->p_slock);
888 *status = KW_EXITCODE(p->p_xexit, p->p_xsig);
889 if (options & WNOWAIT) {
891 * Only poll, returning the status. Caller does not wish to
892 * release the proc struct just yet.
895 sx_xunlock(&proctree_lock);
900 sigqueue_take(p->p_ksi);
904 * If we got the child via a ptrace 'attach', we need to give it back
907 if (p->p_oppid != p->p_pptr->p_pid) {
909 t = proc_realparent(p);
913 "wait: traced child %d moved back to parent %d", p->p_pid,
915 proc_reparent(p, t, false);
917 pksignal(t, SIGCHLD, p->p_ksi);
919 cv_broadcast(&p->p_pwait);
921 sx_xunlock(&proctree_lock);
927 * Remove other references to this process to ensure we have an
928 * exclusive reference.
930 sx_xlock(PIDHASHLOCK(p->p_pid));
931 LIST_REMOVE(p, p_hash);
932 sx_xunlock(PIDHASHLOCK(p->p_pid));
933 LIST_REMOVE(p, p_sibling);
934 reaper_abandon_children(p, true);
937 proc_clear_orphan(p);
940 if (p->p_procdesc != NULL)
942 sx_xunlock(&proctree_lock);
944 proc_id_clear(PROC_ID_PID, p->p_pid);
947 knlist_detach(p->p_klist);
952 * Removal from allproc list and process group list paired with
953 * PROC_LOCK which was executed during that time should guarantee
954 * nothing can reach this process anymore. As such further locking
957 p->p_xexit = p->p_xsig = 0; /* XXX: why? */
960 ruadd(&q->p_stats->p_cru, &q->p_crux, &p->p_ru, &p->p_rux);
964 * Decrement the count of procs running with this uid.
966 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
969 * Destroy resource accounting information associated with the process.
974 racct_sub(p, RACCT_NPROC, 1);
981 * Free credentials, arguments, and sigacts.
984 pargs_drop(p->p_args);
986 sigacts_free(p->p_sigacts);
990 * Do any thread-system specific cleanups.
995 * Give vm and machine-dependent layer a chance to free anything that
996 * cpu_exit couldn't release while still running in process context.
1000 mac_proc_destroy(p);
1003 KASSERT(FIRST_THREAD_IN_PROC(p),
1004 ("proc_reap: no residual thread!"));
1005 uma_zfree(proc_zone, p);
1006 atomic_add_int(&nprocs, -1);
1010 proc_to_reap(struct thread *td, struct proc *p, idtype_t idtype, id_t id,
1011 int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
1016 sx_assert(&proctree_lock, SA_XLOCKED);
1022 if (p->p_procdesc == NULL ||
1023 (p->p_pptr == td->td_proc &&
1024 (p->p_flag & P_TRACED) != 0)) {
1031 if (p->p_pid != (pid_t)id) {
1037 if (p->p_pgid != (pid_t)id) {
1043 if (p->p_session->s_sid != (pid_t)id) {
1049 if (p->p_ucred->cr_uid != (uid_t)id) {
1055 if (p->p_ucred->cr_gid != (gid_t)id) {
1061 if (p->p_ucred->cr_prison->pr_id != (int)id) {
1067 * It seems that the thread structures get zeroed out
1068 * at process exit. This makes it impossible to
1069 * support P_SETID, P_CID or P_CPUID.
1076 if (p_canwait(td, p)) {
1081 if (((options & WEXITED) == 0) && (p->p_state == PRS_ZOMBIE)) {
1087 * This special case handles a kthread spawned by linux_clone
1088 * (see linux_misc.c). The linux_wait4 and linux_waitpid
1089 * functions need to be able to distinguish between waiting
1090 * on a process and waiting on a thread. It is a thread if
1091 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
1092 * signifies we want to wait for threads and not processes.
1094 if ((p->p_sigparent != SIGCHLD) ^
1095 ((options & WLINUXCLONE) != 0)) {
1100 if (siginfo != NULL) {
1101 bzero(siginfo, sizeof(*siginfo));
1102 siginfo->si_errno = 0;
1105 * SUSv4 requires that the si_signo value is always
1106 * SIGCHLD. Obey it despite the rfork(2) interface
1107 * allows to request other signal for child exit
1110 siginfo->si_signo = SIGCHLD;
1113 * This is still a rough estimate. We will fix the
1114 * cases TRAPPED, STOPPED, and CONTINUED later.
1116 if (WCOREDUMP(p->p_xsig)) {
1117 siginfo->si_code = CLD_DUMPED;
1118 siginfo->si_status = WTERMSIG(p->p_xsig);
1119 } else if (WIFSIGNALED(p->p_xsig)) {
1120 siginfo->si_code = CLD_KILLED;
1121 siginfo->si_status = WTERMSIG(p->p_xsig);
1123 siginfo->si_code = CLD_EXITED;
1124 siginfo->si_status = p->p_xexit;
1127 siginfo->si_pid = p->p_pid;
1128 siginfo->si_uid = p->p_ucred->cr_uid;
1131 * The si_addr field would be useful additional
1132 * detail, but apparently the PC value may be lost
1133 * when we reach this point. bzero() above sets
1134 * siginfo->si_addr to NULL.
1139 * There should be no reason to limit resources usage info to
1140 * exited processes only. A snapshot about any resources used
1141 * by a stopped process may be exactly what is needed.
1143 if (wrusage != NULL) {
1144 rup = &wrusage->wru_self;
1147 calcru(p, &rup->ru_utime, &rup->ru_stime);
1150 rup = &wrusage->wru_children;
1151 *rup = p->p_stats->p_cru;
1152 calccru(p, &rup->ru_utime, &rup->ru_stime);
1155 if (p->p_state == PRS_ZOMBIE && !check_only) {
1156 proc_reap(td, p, status, options);
1163 kern_wait(struct thread *td, pid_t pid, int *status, int options,
1164 struct rusage *rusage)
1166 struct __wrusage wru, *wrup;
1172 * Translate the special pid values into the (idtype, pid)
1173 * pair for kern_wait6. The WAIT_MYPGRP case is handled by
1174 * kern_wait6() on its own.
1176 if (pid == WAIT_ANY) {
1179 } else if (pid < 0) {
1193 * For backward compatibility we implicitly add flags WEXITED
1194 * and WTRAPPED here.
1196 options |= WEXITED | WTRAPPED;
1197 ret = kern_wait6(td, idtype, id, status, options, wrup, NULL);
1199 *rusage = wru.wru_self;
1204 report_alive_proc(struct thread *td, struct proc *p, siginfo_t *siginfo,
1205 int *status, int options, int si_code)
1209 PROC_LOCK_ASSERT(p, MA_OWNED);
1210 sx_assert(&proctree_lock, SA_XLOCKED);
1211 MPASS(si_code == CLD_TRAPPED || si_code == CLD_STOPPED ||
1212 si_code == CLD_CONTINUED);
1214 cont = si_code == CLD_CONTINUED;
1215 if ((options & WNOWAIT) == 0) {
1217 p->p_flag &= ~P_CONTINUED;
1219 p->p_flag |= P_WAITED;
1220 if (kern_wait_dequeue_sigchld &&
1221 (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
1222 PROC_LOCK(td->td_proc);
1223 sigqueue_take(p->p_ksi);
1224 PROC_UNLOCK(td->td_proc);
1227 sx_xunlock(&proctree_lock);
1228 if (siginfo != NULL) {
1229 siginfo->si_code = si_code;
1230 siginfo->si_status = cont ? SIGCONT : p->p_xsig;
1233 *status = cont ? SIGCONT : W_STOPCODE(p->p_xsig);
1235 td->td_retval[0] = p->p_pid;
1239 kern_wait6(struct thread *td, idtype_t idtype, id_t id, int *status,
1240 int options, struct __wrusage *wrusage, siginfo_t *siginfo)
1244 int error, nfound, ret;
1247 AUDIT_ARG_VALUE((int)idtype); /* XXX - This is likely wrong! */
1248 AUDIT_ARG_PID((pid_t)id); /* XXX - This may be wrong! */
1249 AUDIT_ARG_VALUE(options);
1253 if ((pid_t)id == WAIT_MYPGRP && (idtype == P_PID || idtype == P_PGID)) {
1255 id = (id_t)q->p_pgid;
1260 /* If we don't know the option, just return. */
1261 if ((options & ~(WUNTRACED | WNOHANG | WCONTINUED | WNOWAIT |
1262 WEXITED | WTRAPPED | WLINUXCLONE)) != 0)
1264 if ((options & (WEXITED | WUNTRACED | WCONTINUED | WTRAPPED)) == 0) {
1266 * We will be unable to find any matching processes,
1267 * because there are no known events to look for.
1268 * Prefer to return error instead of blocking
1275 if (q->p_flag & P_STATCHILD) {
1277 q->p_flag &= ~P_STATCHILD;
1280 sx_xlock(&proctree_lock);
1283 LIST_FOREACH(p, &q->p_children, p_sibling) {
1285 ret = proc_to_reap(td, p, idtype, id, status, options,
1286 wrusage, siginfo, 0);
1289 else if (ret != 1) {
1290 td->td_retval[0] = pid;
1295 PROC_LOCK_ASSERT(p, MA_OWNED);
1297 if ((options & WTRAPPED) != 0 &&
1298 (p->p_flag & P_TRACED) != 0) {
1301 ((p->p_flag & (P_STOPPED_TRACE | P_STOPPED_SIG)) &&
1302 p->p_suspcount == p->p_numthreads &&
1303 (p->p_flag & P_WAITED) == 0);
1307 "wait: returning trapped pid %d status %#x "
1308 "(xstat %d) xthread %d",
1309 p->p_pid, W_STOPCODE(p->p_xsig), p->p_xsig,
1310 p->p_xthread != NULL ?
1311 p->p_xthread->td_tid : -1);
1312 report_alive_proc(td, p, siginfo, status,
1313 options, CLD_TRAPPED);
1317 if ((options & WUNTRACED) != 0 &&
1318 (p->p_flag & P_STOPPED_SIG) != 0) {
1320 report = (p->p_suspcount == p->p_numthreads &&
1321 ((p->p_flag & P_WAITED) == 0));
1324 report_alive_proc(td, p, siginfo, status,
1325 options, CLD_STOPPED);
1329 if ((options & WCONTINUED) != 0 &&
1330 (p->p_flag & P_CONTINUED) != 0) {
1331 report_alive_proc(td, p, siginfo, status, options,
1339 * Look in the orphans list too, to allow the parent to
1340 * collect it's child exit status even if child is being
1343 * Debugger detaches from the parent upon successful
1344 * switch-over from parent to child. At this point due to
1345 * re-parenting the parent loses the child to debugger and a
1346 * wait4(2) call would report that it has no children to wait
1347 * for. By maintaining a list of orphans we allow the parent
1348 * to successfully wait until the child becomes a zombie.
1351 LIST_FOREACH(p, &q->p_orphans, p_orphan) {
1352 ret = proc_to_reap(td, p, idtype, id, NULL, options,
1355 KASSERT(ret != -1, ("reaped an orphan (pid %d)",
1356 (int)td->td_retval[0]));
1364 sx_xunlock(&proctree_lock);
1367 if (options & WNOHANG) {
1368 sx_xunlock(&proctree_lock);
1369 td->td_retval[0] = 0;
1373 if (q->p_flag & P_STATCHILD) {
1374 q->p_flag &= ~P_STATCHILD;
1378 sx_xunlock(&proctree_lock);
1379 error = msleep(q, &q->p_mtx, PWAIT | PCATCH | PDROP, "wait", 0);
1386 proc_add_orphan(struct proc *child, struct proc *parent)
1389 sx_assert(&proctree_lock, SX_XLOCKED);
1390 KASSERT((child->p_flag & P_TRACED) != 0,
1391 ("proc_add_orphan: not traced"));
1393 if (LIST_EMPTY(&parent->p_orphans)) {
1394 child->p_treeflag |= P_TREE_FIRST_ORPHAN;
1395 LIST_INSERT_HEAD(&parent->p_orphans, child, p_orphan);
1397 LIST_INSERT_AFTER(LIST_FIRST(&parent->p_orphans),
1400 child->p_treeflag |= P_TREE_ORPHANED;
1404 * Make process 'parent' the new parent of process 'child'.
1405 * Must be called with an exclusive hold of proctree lock.
1408 proc_reparent(struct proc *child, struct proc *parent, bool set_oppid)
1411 sx_assert(&proctree_lock, SX_XLOCKED);
1412 PROC_LOCK_ASSERT(child, MA_OWNED);
1413 if (child->p_pptr == parent)
1416 PROC_LOCK(child->p_pptr);
1417 sigqueue_take(child->p_ksi);
1418 PROC_UNLOCK(child->p_pptr);
1419 LIST_REMOVE(child, p_sibling);
1420 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1422 proc_clear_orphan(child);
1423 if ((child->p_flag & P_TRACED) != 0) {
1424 proc_add_orphan(child, child->p_pptr);
1427 child->p_pptr = parent;
1429 child->p_oppid = parent->p_pid;