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
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
10 * Redistribution and use in source and binary forms, with or without
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
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
39 * $FreeBSD: src/sys/kern/kern_exit.c,v 1.92.2.11 2003/01/13 22:51:16 dillon Exp $
40 * $DragonFly: src/sys/kern/kern_exit.c,v 1.91 2008/05/18 20:02:02 nth Exp $
43 #include "opt_compat.h"
44 #include "opt_ktrace.h"
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/sysproto.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
52 #include <sys/ktrace.h>
53 #include <sys/pioctl.h>
56 #include <sys/vnode.h>
57 #include <sys/resourcevar.h>
58 #include <sys/signalvar.h>
59 #include <sys/taskqueue.h>
60 #include <sys/ptrace.h>
61 #include <sys/acct.h> /* for acct_process() function prototype */
62 #include <sys/filedesc.h>
66 #include <sys/kern_syscall.h>
67 #include <sys/upcall.h>
69 #include <sys/unistd.h>
70 #include <sys/eventhandler.h>
71 #include <sys/dsched.h>
74 #include <vm/vm_param.h>
77 #include <vm/vm_map.h>
78 #include <vm/vm_extern.h>
81 #include <sys/refcount.h>
82 #include <sys/thread2.h>
83 #include <sys/sysref2.h>
84 #include <sys/mplock2.h>
86 static void reaplwps(void *context, int dummy);
87 static void reaplwp(struct lwp *lp);
88 static void killlwps(struct lwp *lp);
90 static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
91 static MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
93 static struct lwkt_token deadlwp_token = LWKT_TOKEN_INITIALIZER(deadlwp_token);
96 * callout list for things to do at exit time
100 TAILQ_ENTRY(exitlist) next;
103 TAILQ_HEAD(exit_list_head, exitlist);
104 static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
109 struct task *deadlwp_task[MAXCPU];
110 struct lwplist deadlwp_list[MAXCPU];
116 * SYS_EXIT_ARGS(int rval)
119 sys_exit(struct exit_args *uap)
121 exit1(W_EXITCODE(uap->rval, 0));
127 * Death of a lwp or process with optional bells and whistles.
132 sys_extexit(struct extexit_args *uap)
134 struct proc *p = curproc;
138 action = EXTEXIT_ACTION(uap->how);
139 who = EXTEXIT_WHO(uap->how);
141 /* Check parameters before we might perform some action */
154 error = copyout(&uap->status, uap->addr, sizeof(uap->status));
162 lwkt_gettoken(&p->p_token);
167 * Be sure only to perform a simple lwp exit if there is at
168 * least one more lwp in the proc, which will call exit1()
169 * later, otherwise the proc will be an UNDEAD and not even a
172 if (p->p_nthreads > 1) {
173 lwp_exit(0); /* called w/ p_token held */
176 /* else last lwp in proc: do the real thing */
178 default: /* to help gcc */
180 lwkt_reltoken(&p->p_token);
181 exit1(W_EXITCODE(uap->status, 0));
186 lwkt_reltoken(&p->p_token); /* safety */
190 * Kill all lwps associated with the current process except the
191 * current lwp. Return an error if we race another thread trying to
192 * do the same thing and lose the race.
194 * If forexec is non-zero the current thread and process flags are
195 * cleaned up so they can be reused.
197 * Caller must hold curproc->p_token
200 killalllwps(int forexec)
202 struct lwp *lp = curthread->td_lwp;
203 struct proc *p = lp->lwp_proc;
206 * Interlock against P_WEXIT. Only one of the process's thread
207 * is allowed to do the master exit.
209 if (p->p_flags & P_WEXIT)
211 p->p_flags |= P_WEXIT;
214 * Interlock with LWP_MP_WEXIT and kill any remaining LWPs
216 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
217 if (p->p_nthreads > 1)
221 * If doing this for an exec, clean up the remaining thread
222 * (us) for continuing operation after all the other threads
226 atomic_clear_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
227 p->p_flags &= ~P_WEXIT;
233 * Kill all LWPs except the current one. Do not try to signal
234 * LWPs which have exited on their own or have already been
238 killlwps(struct lwp *lp)
240 struct proc *p = lp->lwp_proc;
244 * Kill the remaining LWPs. We must send the signal before setting
245 * LWP_MP_WEXIT. The setting of WEXIT is optional but helps reduce
246 * races. tlp must be held across the call as it might block and
247 * allow the target lwp to rip itself out from under our loop.
249 FOREACH_LWP_IN_PROC(tlp, p) {
251 lwkt_gettoken(&tlp->lwp_token);
252 if ((tlp->lwp_mpflags & LWP_MP_WEXIT) == 0) {
253 lwpsignal(p, tlp, SIGKILL);
254 atomic_set_int(&tlp->lwp_mpflags, LWP_MP_WEXIT);
256 lwkt_reltoken(&tlp->lwp_token);
261 * Wait for everything to clear out.
263 while (p->p_nthreads > 1) {
264 tsleep(&p->p_nthreads, 0, "killlwps", 0);
269 * Exit: deallocate address space and other resources, change proc state
270 * to zombie, and unlink proc from allproc and parent's lists. Save exit
271 * status and rusage for wait(). Check for child processes and orphan them.
276 struct thread *td = curthread;
277 struct proc *p = td->td_proc;
278 struct lwp *lp = td->td_lwp;
285 lwkt_gettoken(&p->p_token);
288 kprintf("init died (signal %d, exit %d)\n",
289 WTERMSIG(rv), WEXITSTATUS(rv));
290 panic("Going nowhere without my init!");
292 varsymset_clean(&p->p_varsymset);
293 lockuninit(&p->p_varsymset.vx_lock);
296 * Kill all lwps associated with the current process, return an
297 * error if we race another thread trying to do the same thing
300 error = killalllwps(0);
306 caps_exit(lp->lwp_thread);
308 /* are we a task leader? */
309 if (p == p->p_leader) {
310 struct kill_args killArgs;
311 killArgs.signum = SIGKILL;
314 killArgs.pid = q->p_pid;
316 * The interface for kill is better
317 * than the internal signal
324 tsleep((caddr_t)p, 0, "exit1", 0);
330 STOPEVENT(p, S_EXIT, rv);
331 p->p_flags |= P_POSTEXIT; /* stop procfs stepping */
334 * Check if any loadable modules need anything done at process exit.
335 * e.g. SYSV IPC stuff
336 * XXX what if one of these generates an error?
339 EVENTHANDLER_INVOKE(process_exit, p);
342 * XXX: imho, the eventhandler stuff is much cleaner than this.
343 * Maybe we should move everything to use eventhandler.
345 TAILQ_FOREACH(ep, &exit_list, next)
348 if (p->p_flags & P_PROFIL)
351 SIGEMPTYSET(p->p_siglist);
352 SIGEMPTYSET(lp->lwp_siglist);
353 if (timevalisset(&p->p_realtimer.it_value))
354 callout_stop_sync(&p->p_ithandle);
357 * Reset any sigio structures pointing to us as a result of
358 * F_SETOWN with our pid.
360 funsetownlst(&p->p_sigiolst);
363 * Close open files and release open-file table.
368 if(p->p_leader->p_peers) {
370 while(q->p_peers != p)
372 q->p_peers = p->p_peers;
373 wakeup((caddr_t)p->p_leader);
377 * XXX Shutdown SYSV semaphores
381 KKASSERT(p->p_numposixlocks == 0);
383 /* The next two chunks should probably be moved to vmspace_exit. */
387 * Release upcalls associated with this process
393 * Clean up data related to virtual kernel operation. Clean up
394 * any vkernel context related to the current lwp now so we can
398 vkernel_lwp_exit(lp);
403 * Release user portion of address space.
404 * This releases references to vnodes,
405 * which could cause I/O if the file has been unlinked.
406 * Need to do this early enough that we can still sleep.
407 * Can't free the entire vmspace as the kernel stack
408 * may be mapped within that space also.
410 * Processes sharing the same vmspace may exit in one order, and
411 * get cleaned up by vmspace_exit() in a different order. The
412 * last exiting process to reach this point releases as much of
413 * the environment as it can, and the last process cleaned up
414 * by vmspace_exit() (which decrements exitingcnt) cleans up the
417 vmspace_exitbump(vm);
418 sysref_put(&vm->vm_sysref);
420 if (SESS_LEADER(p)) {
421 struct session *sp = p->p_session;
425 * We are the controlling process. Signal the
426 * foreground process group, drain the controlling
427 * terminal, and revoke access to the controlling
430 * NOTE: while waiting for the process group to exit
431 * it is possible that one of the processes in the
432 * group will revoke the tty, so the ttyclosesession()
433 * function will re-check sp->s_ttyvp.
435 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
436 if (sp->s_ttyp->t_pgrp)
437 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
439 ttyclosesession(sp, 1); /* also revoke */
442 * Release the tty. If someone has it open via
443 * /dev/tty then close it (since they no longer can
444 * once we've NULL'd it out).
446 ttyclosesession(sp, 0);
449 * s_ttyp is not zero'd; we use this to indicate
450 * that the session once had a controlling terminal.
451 * (for logging and informational purposes)
456 fixjobc(p, p->p_pgrp, 0);
457 (void)acct_process(p);
463 ktrdestroy(&p->p_tracenode);
467 * Release reference to text vnode
469 if ((vtmp = p->p_textvp) != NULL) {
474 /* Release namecache handle to text file */
475 if (p->p_textnch.ncp)
476 cache_drop(&p->p_textnch);
479 * We have to handle PPWAIT here or proc_move_allproc_zombie()
480 * will block on the PHOLD() the parent is doing.
482 if (p->p_flags & P_PPWAIT) {
483 p->p_flags &= ~P_PPWAIT;
488 * Move the process to the zombie list. This will block
489 * until the process p_lock count reaches 0. The process will
490 * not be reaped until TDF_EXITING is set by cpu_thread_exit(),
491 * which is called from cpu_proc_exit().
493 proc_move_allproc_zombie(p);
496 * Reparent all of this process's children to the init process.
497 * We must hold initproc->p_token in order to mess with
498 * initproc->p_children. We already hold p->p_token (to remove
499 * the children from our list).
501 q = LIST_FIRST(&p->p_children);
503 lwkt_gettoken(&initproc->p_token);
505 nq = LIST_NEXT(q, p_sibling);
506 LIST_REMOVE(q, p_sibling);
507 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling);
508 q->p_pptr = initproc;
509 q->p_sigparent = SIGCHLD;
511 * Traced processes are killed
512 * since their existence means someone is screwing up.
514 if (q->p_flags & P_TRACED) {
515 q->p_flags &= ~P_TRACED;
520 lwkt_reltoken(&initproc->p_token);
525 * Save exit status and final rusage info, adding in child rusage
526 * info and self times.
528 calcru_proc(p, &p->p_ru);
529 ruadd(&p->p_ru, &p->p_cru);
532 * notify interested parties of our demise.
534 KNOTE(&p->p_klist, NOTE_EXIT);
537 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
538 * flag set, or if the handler is set to SIG_IGN, notify process 1
539 * instead (and hope it will handle this situation).
541 if (p->p_pptr->p_sigacts->ps_flag &
542 (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
543 struct proc *pp = p->p_pptr;
546 proc_reparent(p, initproc);
549 * If this was the last child of our parent, notify
550 * parent, so in case he was wait(2)ing, he will
551 * continue. This function interlocks with pptr->p_token.
553 if (LIST_EMPTY(&pp->p_children))
558 /* lwkt_gettoken(&proc_token); */
561 if (p->p_sigparent && q != initproc) {
562 ksignal(q, p->p_sigparent);
567 p->p_flags &= ~P_TRACED;
571 /* lwkt_reltoken(&proc_token); */
572 /* NOTE: p->p_pptr can get ripped out */
574 * cpu_exit is responsible for clearing curproc, since
575 * it is heavily integrated with the thread/switching sequence.
577 * Other substructures are freed from wait().
582 * Release the current user process designation on the process so
583 * the userland scheduler can work in someone else.
585 p->p_usched->release_curproc(lp);
588 * Finally, call machine-dependent code to release as many of the
589 * lwp's resources as we can and halt execution of this thread.
595 * Eventually called by every exiting LWP
597 * p->p_token must be held. mplock may be held and will be released.
600 lwp_exit(int masterexit)
602 struct thread *td = curthread;
603 struct lwp *lp = td->td_lwp;
604 struct proc *p = lp->lwp_proc;
608 * lwp_exit() may be called without setting LWP_MP_WEXIT, so
609 * make sure it is set here.
611 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
612 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
615 * Clean up any virtualization
618 vkernel_lwp_exit(lp);
621 * Clean up select/poll support
623 kqueue_terminate(&lp->lwp_kqueue);
626 * Clean up any syscall-cached ucred
629 crfree(td->td_ucred);
634 * Nobody actually wakes us when the lock
635 * count reaches zero, so just wait one tick.
637 while (lp->lwp_lock > 0)
638 tsleep(lp, 0, "lwpexit", 1);
640 /* Hand down resource usage to our proc */
641 ruadd(&p->p_ru, &lp->lwp_ru);
644 * If we don't hold the process until the LWP is reaped wait*()
645 * may try to dispose of its vmspace before all the LWPs have
646 * actually terminated.
651 * Do any remaining work that might block on us. We should be
652 * coded such that further blocking is ok after decrementing
653 * p_nthreads but don't take the chance.
655 dsched_exit_thread(td);
656 biosched_done(curthread);
659 * We have to use the reaper for all the LWPs except the one doing
660 * the master exit. The LWP doing the master exit can just be
661 * left on p_lwps and the process reaper will deal with it
662 * synchronously, which is much faster.
664 * Wakeup anyone waiting on p_nthreads to drop to 1 or 0.
666 * The process is left held until the reaper calls lwp_dispose() on
667 * the lp (after calling lwp_wait()).
669 if (masterexit == 0) {
670 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
672 if (p->p_nthreads <= 1)
674 lwkt_gettoken(&deadlwp_token);
675 LIST_INSERT_HEAD(&deadlwp_list[mycpuid], lp, u.lwp_reap_entry);
676 taskqueue_enqueue(taskqueue_thread[mycpuid],
677 deadlwp_task[mycpuid]);
678 lwkt_reltoken(&deadlwp_token);
681 if (p->p_nthreads <= 1)
686 * Release p_token. Issue the wakeup() on p_nthreads if necessary,
687 * as late as possible to give us a chance to actually deschedule and
688 * switch away before another cpu core hits reaplwp().
690 lwkt_reltoken(&p->p_token);
692 wakeup(&p->p_nthreads);
697 * Wait until a lwp is completely dead. The final interlock in this drama
698 * is when TDF_EXITING is set in cpu_thread_exit() just before the final
701 * At the point TDF_EXITING is set a complete exit is accomplished when
702 * TDF_RUNNING and TDF_PREEMPT_LOCK are both clear.
704 * Returns non-zero on success, and zero if the caller needs to retry
708 lwp_wait(struct lwp *lp)
710 struct thread *td = lp->lwp_thread;;
712 KKASSERT(lwkt_preempted_proc() != lp);
715 * Wait until the lp has entered its low level exit and wait
716 * until other cores with refs on the lp (e.g. for ps or signaling)
719 if (lp->lwp_lock > 0) {
720 tsleep(lp, 0, "lwpwait1", 1);
725 * Wait until the thread is no longer references and no longer
726 * runnable or preempted (i.e. finishes its low level exit).
729 tsleep(td, 0, "lwpwait2", 1);
734 * The lwp's thread may still be in the middle
735 * of switching away, we can't rip its stack out from
736 * under it until TDF_EXITING is set and both
737 * TDF_RUNNING and TDF_PREEMPT_LOCK are clear.
738 * TDF_PREEMPT_LOCK must be checked because TDF_RUNNING
739 * will be cleared temporarily if a thread gets
742 * YYY no wakeup occurs, so we simply return failure
743 * and let the caller deal with sleeping and calling
746 if ((td->td_flags & (TDF_RUNNING |
748 TDF_EXITING)) != TDF_EXITING) {
749 tsleep(lp, 0, "lwpwait2", 1);
752 KASSERT((td->td_flags & (TDF_RUNQ|TDF_TSLEEPQ)) == 0,
753 ("lwp_wait: td %p (%s) still on run or sleep queue",
759 * Release the resources associated with a lwp.
760 * The lwp must be completely dead.
763 lwp_dispose(struct lwp *lp)
765 struct thread *td = lp->lwp_thread;;
767 KKASSERT(lwkt_preempted_proc() != lp);
768 KKASSERT(td->td_refs == 0);
769 KKASSERT((td->td_flags & (TDF_RUNNING |
771 TDF_EXITING)) == TDF_EXITING);
778 lp->lwp_thread = NULL;
779 lwkt_free_thread(td);
788 sys_wait4(struct wait_args *uap)
790 struct rusage rusage;
793 error = kern_wait(uap->pid, (uap->status ? &status : NULL),
794 uap->options, (uap->rusage ? &rusage : NULL),
795 &uap->sysmsg_result);
797 if (error == 0 && uap->status)
798 error = copyout(&status, uap->status, sizeof(*uap->status));
799 if (error == 0 && uap->rusage)
800 error = copyout(&rusage, uap->rusage, sizeof(*uap->rusage));
807 * wait_args(int pid, int *status, int options, struct rusage *rusage)
812 kern_wait(pid_t pid, int *status, int options, struct rusage *rusage, int *res)
814 struct thread *td = curthread;
816 struct proc *q = td->td_proc;
824 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
827 lwkt_gettoken(&q->p_token);
830 * All sorts of things can change due to blocking so we have to loop
831 * all the way back up here.
833 * The problem is that if a process group is stopped and the parent
834 * is doing a wait*(..., WUNTRACED, ...), it will see the STOP
835 * of the child and then stop itself when it tries to return from the
836 * system call. When the process group is resumed the parent will
837 * then get the STOP status even though the child has now resumed
838 * (a followup wait*() will get the CONT status).
840 * Previously the CONT would overwrite the STOP because the tstop
841 * was handled within tsleep(), and the parent would only see
842 * the CONT when both are stopped and continued together. This little
843 * two-line hack restores this effect.
845 while (q->p_stat == SSTOP)
853 * NOTE: We don't want to break q's p_token in the loop for the
854 * case where no children are found or we risk breaking the
855 * interlock between child and parent.
857 LIST_FOREACH(p, &q->p_children, p_sibling) {
858 if (pid != WAIT_ANY &&
859 p->p_pid != pid && p->p_pgid != -pid) {
864 * This special case handles a kthread spawned by linux_clone
865 * (see linux_misc.c). The linux_wait4 and linux_waitpid
866 * functions need to be able to distinguish between waiting
867 * on a process and waiting on a thread. It is a thread if
868 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
869 * signifies we want to wait for threads and not processes.
871 if ((p->p_sigparent != SIGCHLD) ^
872 ((options & WLINUXCLONE) != 0)) {
877 if (p->p_stat == SZOMB) {
879 * We may go into SZOMB with threads still present.
880 * We must wait for them to exit before we can reap
881 * the master thread, otherwise we may race reaping
882 * non-master threads.
884 lwkt_gettoken(&p->p_token);
885 while (p->p_nthreads > 0) {
886 tsleep(&p->p_nthreads, 0, "lwpzomb", hz);
890 * Reap any LWPs left in p->p_lwps. This is usually
891 * just the last LWP. This must be done before
892 * we loop on p_lock since the lwps hold a ref on
893 * it as a vmspace interlock.
895 * Once that is accomplished p_nthreads had better
898 while ((lp = RB_ROOT(&p->p_lwp_tree)) != NULL) {
899 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
902 KKASSERT(p->p_nthreads == 0);
905 * Don't do anything really bad until all references
906 * to the process go away. This may include other
907 * LWPs which are still in the process of being
908 * reaped. We can't just pull the rug out from under
909 * them because they may still be using the VM space.
911 * Certain kernel facilities such as /proc will also
912 * put a hold on the process for short periods of
915 PSTALL(p, "reap3", 0);
917 /* Take care of our return values. */
919 p->p_usched->heuristic_exiting(td->td_lwp, p);
922 *status = p->p_xstat;
926 * If we got the child via a ptrace 'attach',
927 * we need to give it back to the old parent.
929 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
936 lwkt_reltoken(&p->p_token);
941 * Unlink the proc from its process group so that
942 * the following operations won't lead to an
943 * inconsistent state for processes running down
946 proc_remove_zombie(p);
947 lwkt_reltoken(&p->p_token);
951 ruadd(&q->p_cru, &p->p_ru);
954 * Decrement the count of procs running with this uid.
956 chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
959 * Free up credentials.
965 * Remove unused arguments
969 if (pa && refcount_release(&pa->ar_ref)) {
976 if (ps && refcount_release(&ps->ps_refcnt)) {
977 kfree(ps, M_SUBPROC);
982 * Our exitingcount was incremented when the process
983 * became a zombie, now that the process has been
984 * removed from (almost) all lists we should be able
985 * to safely destroy its vmspace. Wait for any current
986 * holders to go away (so the vmspace remains stable),
989 PSTALL(p, "reap4", 0);
991 PSTALL(p, "reap5", 0);
994 atomic_add_int(&nprocs, -1);
998 if (p->p_stat == SSTOP && (p->p_flags & P_WAITED) == 0 &&
999 ((p->p_flags & P_TRACED) || (options & WUNTRACED))) {
1000 lwkt_gettoken(&p->p_token);
1001 p->p_flags |= P_WAITED;
1004 p->p_usched->heuristic_exiting(td->td_lwp, p);
1006 *status = W_STOPCODE(p->p_xstat);
1007 /* Zero rusage so we get something consistent. */
1009 bzero(rusage, sizeof(*rusage));
1011 lwkt_reltoken(&p->p_token);
1014 if ((options & WCONTINUED) && (p->p_flags & P_CONTINUED)) {
1015 lwkt_gettoken(&p->p_token);
1017 p->p_usched->heuristic_exiting(td->td_lwp, p);
1018 p->p_flags &= ~P_CONTINUED;
1023 lwkt_reltoken(&p->p_token);
1031 if (options & WNOHANG) {
1038 * Wait for signal - interlocked using q->p_token.
1040 error = tsleep(q, PCATCH, "wait", 0);
1043 lwkt_reltoken(&q->p_token);
1050 * Make process 'parent' the new parent of process 'child'.
1052 * p_children/p_sibling requires the parent's token, and
1053 * changing pptr requires the child's token, so we have to
1054 * get three tokens to do this operation.
1057 proc_reparent(struct proc *child, struct proc *parent)
1059 struct proc *opp = child->p_pptr;
1065 lwkt_gettoken(&opp->p_token);
1066 lwkt_gettoken(&child->p_token);
1067 lwkt_gettoken(&parent->p_token);
1068 KKASSERT(child->p_pptr == opp);
1069 LIST_REMOVE(child, p_sibling);
1070 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1071 child->p_pptr = parent;
1072 lwkt_reltoken(&parent->p_token);
1073 lwkt_reltoken(&child->p_token);
1074 lwkt_reltoken(&opp->p_token);
1080 * The next two functions are to handle adding/deleting items on the
1084 * Take the arguments given and put them onto the exit callout list,
1085 * However first make sure that it's not already there.
1086 * returns 0 on success.
1090 at_exit(exitlist_fn function)
1092 struct exitlist *ep;
1095 /* Be noisy if the programmer has lost track of things */
1096 if (rm_at_exit(function))
1097 kprintf("WARNING: exit callout entry (%p) already present\n",
1100 ep = kmalloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
1103 ep->function = function;
1104 TAILQ_INSERT_TAIL(&exit_list, ep, next);
1109 * Scan the exit callout list for the given item and remove it.
1110 * Returns the number of items removed (0 or 1)
1113 rm_at_exit(exitlist_fn function)
1115 struct exitlist *ep;
1117 TAILQ_FOREACH(ep, &exit_list, next) {
1118 if (ep->function == function) {
1119 TAILQ_REMOVE(&exit_list, ep, next);
1120 kfree(ep, M_ATEXIT);
1128 * LWP reaper related code.
1131 reaplwps(void *context, int dummy)
1133 struct lwplist *lwplist = context;
1136 lwkt_gettoken(&deadlwp_token);
1137 while ((lp = LIST_FIRST(lwplist))) {
1138 LIST_REMOVE(lp, u.lwp_reap_entry);
1141 lwkt_reltoken(&deadlwp_token);
1145 reaplwp(struct lwp *lp)
1147 while (lwp_wait(lp) == 0)
1157 for (cpu = 0; cpu < ncpus; cpu++) {
1158 LIST_INIT(&deadlwp_list[cpu]);
1159 deadlwp_task[cpu] = kmalloc(sizeof(*deadlwp_task[cpu]),
1160 M_DEVBUF, M_WAITOK);
1161 TASK_INIT(deadlwp_task[cpu], 0, reaplwps, &deadlwp_list[cpu]);
1165 SYSINIT(deadlwpinit, SI_SUB_CONFIGURE, SI_ORDER_ANY, deadlwp_init, NULL);