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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 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
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 * If parent is waiting for us to exit or exec,
352 * P_PPWAIT is set; we will wakeup the parent below.
354 p->p_flags &= ~(P_TRACED | P_PPWAIT);
355 SIGEMPTYSET(p->p_siglist);
356 SIGEMPTYSET(lp->lwp_siglist);
357 if (timevalisset(&p->p_realtimer.it_value))
358 callout_stop(&p->p_ithandle);
361 * Reset any sigio structures pointing to us as a result of
362 * F_SETOWN with our pid.
364 funsetownlst(&p->p_sigiolst);
367 * Close open files and release open-file table.
372 if(p->p_leader->p_peers) {
374 while(q->p_peers != p)
376 q->p_peers = p->p_peers;
377 wakeup((caddr_t)p->p_leader);
381 * XXX Shutdown SYSV semaphores
385 KKASSERT(p->p_numposixlocks == 0);
387 /* The next two chunks should probably be moved to vmspace_exit. */
391 * Release upcalls associated with this process
397 * Clean up data related to virtual kernel operation. Clean up
398 * any vkernel context related to the current lwp now so we can
402 vkernel_lwp_exit(lp);
407 * Release user portion of address space.
408 * This releases references to vnodes,
409 * which could cause I/O if the file has been unlinked.
410 * Need to do this early enough that we can still sleep.
411 * Can't free the entire vmspace as the kernel stack
412 * may be mapped within that space also.
414 * Processes sharing the same vmspace may exit in one order, and
415 * get cleaned up by vmspace_exit() in a different order. The
416 * last exiting process to reach this point releases as much of
417 * the environment as it can, and the last process cleaned up
418 * by vmspace_exit() (which decrements exitingcnt) cleans up the
421 vmspace_exitbump(vm);
422 sysref_put(&vm->vm_sysref);
424 if (SESS_LEADER(p)) {
425 struct session *sp = p->p_session;
429 * We are the controlling process. Signal the
430 * foreground process group, drain the controlling
431 * terminal, and revoke access to the controlling
434 * NOTE: while waiting for the process group to exit
435 * it is possible that one of the processes in the
436 * group will revoke the tty, so the ttyclosesession()
437 * function will re-check sp->s_ttyvp.
439 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
440 if (sp->s_ttyp->t_pgrp)
441 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
443 ttyclosesession(sp, 1); /* also revoke */
446 * Release the tty. If someone has it open via
447 * /dev/tty then close it (since they no longer can
448 * once we've NULL'd it out).
450 ttyclosesession(sp, 0);
453 * s_ttyp is not zero'd; we use this to indicate
454 * that the session once had a controlling terminal.
455 * (for logging and informational purposes)
460 fixjobc(p, p->p_pgrp, 0);
461 (void)acct_process(p);
467 ktrdestroy(&p->p_tracenode);
471 * Release reference to text vnode
473 if ((vtmp = p->p_textvp) != NULL) {
478 /* Release namecache handle to text file */
479 if (p->p_textnch.ncp)
480 cache_drop(&p->p_textnch);
483 * Move the process to the zombie list. This will block
484 * until the process p_lock count reaches 0. The process will
485 * not be reaped until TDF_EXITING is set by cpu_thread_exit(),
486 * which is called from cpu_proc_exit().
488 proc_move_allproc_zombie(p);
491 * Reparent all of this process's children to the init process.
492 * We must hold initproc->p_token in order to mess with
493 * initproc->p_children. We already hold p->p_token (to remove
494 * the children from our list).
496 q = LIST_FIRST(&p->p_children);
498 lwkt_gettoken(&initproc->p_token);
500 nq = LIST_NEXT(q, p_sibling);
501 LIST_REMOVE(q, p_sibling);
502 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling);
503 q->p_pptr = initproc;
504 q->p_sigparent = SIGCHLD;
506 * Traced processes are killed
507 * since their existence means someone is screwing up.
509 if (q->p_flags & P_TRACED) {
510 q->p_flags &= ~P_TRACED;
515 lwkt_reltoken(&initproc->p_token);
520 * Save exit status and final rusage info, adding in child rusage
521 * info and self times.
523 calcru_proc(p, &p->p_ru);
524 ruadd(&p->p_ru, &p->p_cru);
527 * notify interested parties of our demise.
529 KNOTE(&p->p_klist, NOTE_EXIT);
532 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
533 * flag set, notify process 1 instead (and hope it will handle
536 if (p->p_pptr->p_sigacts->ps_flag & PS_NOCLDWAIT) {
537 struct proc *pp = p->p_pptr;
540 proc_reparent(p, initproc);
543 * If this was the last child of our parent, notify
544 * parent, so in case he was wait(2)ing, he will
545 * continue. This function interlocks with pptr->p_token.
547 if (LIST_EMPTY(&pp->p_children))
552 /* lwkt_gettoken(&proc_token); */
555 if (p->p_sigparent && q != initproc) {
556 ksignal(q, p->p_sigparent);
562 /* lwkt_reltoken(&proc_token); */
563 /* NOTE: p->p_pptr can get ripped out */
565 * cpu_exit is responsible for clearing curproc, since
566 * it is heavily integrated with the thread/switching sequence.
568 * Other substructures are freed from wait().
573 * Release the current user process designation on the process so
574 * the userland scheduler can work in someone else.
576 p->p_usched->release_curproc(lp);
579 * Finally, call machine-dependent code to release as many of the
580 * lwp's resources as we can and halt execution of this thread.
586 * Eventually called by every exiting LWP
588 * p->p_token must be held. mplock may be held and will be released.
591 lwp_exit(int masterexit)
593 struct thread *td = curthread;
594 struct lwp *lp = td->td_lwp;
595 struct proc *p = lp->lwp_proc;
599 * lwp_exit() may be called without setting LWP_MP_WEXIT, so
600 * make sure it is set here.
602 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
603 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
606 * Clean up any virtualization
609 vkernel_lwp_exit(lp);
612 * Clean up select/poll support
614 kqueue_terminate(&lp->lwp_kqueue);
617 * Clean up any syscall-cached ucred
620 crfree(td->td_ucred);
625 * Nobody actually wakes us when the lock
626 * count reaches zero, so just wait one tick.
628 while (lp->lwp_lock > 0)
629 tsleep(lp, 0, "lwpexit", 1);
631 /* Hand down resource usage to our proc */
632 ruadd(&p->p_ru, &lp->lwp_ru);
635 * If we don't hold the process until the LWP is reaped wait*()
636 * may try to dispose of its vmspace before all the LWPs have
637 * actually terminated.
642 * Do any remaining work that might block on us. We should be
643 * coded such that further blocking is ok after decrementing
644 * p_nthreads but don't take the chance.
646 dsched_exit_thread(td);
647 biosched_done(curthread);
650 * We have to use the reaper for all the LWPs except the one doing
651 * the master exit. The LWP doing the master exit can just be
652 * left on p_lwps and the process reaper will deal with it
653 * synchronously, which is much faster.
655 * Wakeup anyone waiting on p_nthreads to drop to 1 or 0.
657 * The process is left held until the reaper calls lwp_dispose() on
658 * the lp (after calling lwp_wait()).
660 if (masterexit == 0) {
661 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
663 if (p->p_nthreads <= 1)
665 lwkt_gettoken(&deadlwp_token);
666 LIST_INSERT_HEAD(&deadlwp_list[mycpuid], lp, u.lwp_reap_entry);
667 taskqueue_enqueue(taskqueue_thread[mycpuid],
668 deadlwp_task[mycpuid]);
669 lwkt_reltoken(&deadlwp_token);
672 if (p->p_nthreads <= 1)
677 * Release p_token. Issue the wakeup() on p_nthreads if necessary,
678 * as late as possible to give us a chance to actually deschedule and
679 * switch away before another cpu core hits reaplwp().
681 lwkt_reltoken(&p->p_token);
683 wakeup(&p->p_nthreads);
688 * Wait until a lwp is completely dead. The final interlock in this drama
689 * is when TDF_EXITING is set in cpu_thread_exit() just before the final
692 * At the point TDF_EXITING is set a complete exit is accomplished when
693 * TDF_RUNNING and TDF_PREEMPT_LOCK are both clear.
695 * Returns non-zero on success, and zero if the caller needs to retry
699 lwp_wait(struct lwp *lp)
701 struct thread *td = lp->lwp_thread;;
703 KKASSERT(lwkt_preempted_proc() != lp);
706 * Wait until the lp has entered its low level exit and wait
707 * until other cores with refs on the lp (e.g. for ps or signaling)
710 if (lp->lwp_lock > 0) {
711 tsleep(lp, 0, "lwpwait1", 1);
716 * Wait until the thread is no longer references and no longer
717 * runnable or preempted (i.e. finishes its low level exit).
720 tsleep(td, 0, "lwpwait2", 1);
725 * The lwp's thread may still be in the middle
726 * of switching away, we can't rip its stack out from
727 * under it until TDF_EXITING is set and both
728 * TDF_RUNNING and TDF_PREEMPT_LOCK are clear.
729 * TDF_PREEMPT_LOCK must be checked because TDF_RUNNING
730 * will be cleared temporarily if a thread gets
733 * YYY no wakeup occurs, so we simply return failure
734 * and let the caller deal with sleeping and calling
737 if ((td->td_flags & (TDF_RUNNING |
739 TDF_EXITING)) != TDF_EXITING) {
740 tsleep(lp, 0, "lwpwait2", 1);
743 KASSERT((td->td_flags & (TDF_RUNQ|TDF_TSLEEPQ)) == 0,
744 ("lwp_wait: td %p (%s) still on run or sleep queue",
750 * Release the resources associated with a lwp.
751 * The lwp must be completely dead.
754 lwp_dispose(struct lwp *lp)
756 struct thread *td = lp->lwp_thread;;
758 KKASSERT(lwkt_preempted_proc() != lp);
759 KKASSERT(td->td_refs == 0);
760 KKASSERT((td->td_flags & (TDF_RUNNING |
762 TDF_EXITING)) == TDF_EXITING);
769 lp->lwp_thread = NULL;
770 lwkt_free_thread(td);
779 sys_wait4(struct wait_args *uap)
781 struct rusage rusage;
784 error = kern_wait(uap->pid, (uap->status ? &status : NULL),
785 uap->options, (uap->rusage ? &rusage : NULL),
786 &uap->sysmsg_result);
788 if (error == 0 && uap->status)
789 error = copyout(&status, uap->status, sizeof(*uap->status));
790 if (error == 0 && uap->rusage)
791 error = copyout(&rusage, uap->rusage, sizeof(*uap->rusage));
798 * wait_args(int pid, int *status, int options, struct rusage *rusage)
803 kern_wait(pid_t pid, int *status, int options, struct rusage *rusage, int *res)
805 struct thread *td = curthread;
807 struct proc *q = td->td_proc;
815 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
818 lwkt_gettoken(&q->p_token);
821 * All sorts of things can change due to blocking so we have to loop
822 * all the way back up here.
824 * The problem is that if a process group is stopped and the parent
825 * is doing a wait*(..., WUNTRACED, ...), it will see the STOP
826 * of the child and then stop itself when it tries to return from the
827 * system call. When the process group is resumed the parent will
828 * then get the STOP status even though the child has now resumed
829 * (a followup wait*() will get the CONT status).
831 * Previously the CONT would overwrite the STOP because the tstop
832 * was handled within tsleep(), and the parent would only see
833 * the CONT when both are stopped and continued together. This little
834 * two-line hack restores this effect.
836 while (q->p_stat == SSTOP)
844 * NOTE: We don't want to break q's p_token in the loop for the
845 * case where no children are found or we risk breaking the
846 * interlock between child and parent.
848 LIST_FOREACH(p, &q->p_children, p_sibling) {
849 if (pid != WAIT_ANY &&
850 p->p_pid != pid && p->p_pgid != -pid) {
855 * This special case handles a kthread spawned by linux_clone
856 * (see linux_misc.c). The linux_wait4 and linux_waitpid
857 * functions need to be able to distinguish between waiting
858 * on a process and waiting on a thread. It is a thread if
859 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
860 * signifies we want to wait for threads and not processes.
862 if ((p->p_sigparent != SIGCHLD) ^
863 ((options & WLINUXCLONE) != 0)) {
868 if (p->p_stat == SZOMB) {
870 * We may go into SZOMB with threads still present.
871 * We must wait for them to exit before we can reap
872 * the master thread, otherwise we may race reaping
873 * non-master threads.
875 lwkt_gettoken(&p->p_token);
876 while (p->p_nthreads > 0) {
877 tsleep(&p->p_nthreads, 0, "lwpzomb", hz);
881 * Reap any LWPs left in p->p_lwps. This is usually
882 * just the last LWP. This must be done before
883 * we loop on p_lock since the lwps hold a ref on
884 * it as a vmspace interlock.
886 * Once that is accomplished p_nthreads had better
889 while ((lp = RB_ROOT(&p->p_lwp_tree)) != NULL) {
890 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
893 KKASSERT(p->p_nthreads == 0);
896 * Don't do anything really bad until all references
897 * to the process go away. This may include other
898 * LWPs which are still in the process of being
899 * reaped. We can't just pull the rug out from under
900 * them because they may still be using the VM space.
902 * Certain kernel facilities such as /proc will also
903 * put a hold on the process for short periods of
907 tsleep(p, 0, "reap3", hz);
909 /* Take care of our return values. */
911 p->p_usched->heuristic_exiting(td->td_lwp, p);
914 *status = p->p_xstat;
918 * If we got the child via a ptrace 'attach',
919 * we need to give it back to the old parent.
921 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
928 lwkt_reltoken(&p->p_token);
933 * Unlink the proc from its process group so that
934 * the following operations won't lead to an
935 * inconsistent state for processes running down
938 proc_remove_zombie(p);
939 lwkt_reltoken(&p->p_token);
943 ruadd(&q->p_cru, &p->p_ru);
946 * Decrement the count of procs running with this uid.
948 chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
951 * Free up credentials.
957 * Remove unused arguments
961 if (pa && refcount_release(&pa->ar_ref)) {
968 if (ps && refcount_release(&ps->ps_refcnt)) {
969 kfree(ps, M_SUBPROC);
974 * Our exitingcount was incremented when the process
975 * became a zombie, now that the process has been
976 * removed from (almost) all lists we should be able
977 * to safely destroy its vmspace. Wait for any current
978 * holders to go away (so the vmspace remains stable),
982 tsleep(p, 0, "reap4", hz);
985 tsleep(p, 0, "reap5", hz);
988 atomic_add_int(&nprocs, -1);
992 if (p->p_stat == SSTOP && (p->p_flags & P_WAITED) == 0 &&
993 ((p->p_flags & P_TRACED) || (options & WUNTRACED))) {
994 lwkt_gettoken(&p->p_token);
995 p->p_flags |= P_WAITED;
998 p->p_usched->heuristic_exiting(td->td_lwp, p);
1000 *status = W_STOPCODE(p->p_xstat);
1001 /* Zero rusage so we get something consistent. */
1003 bzero(rusage, sizeof(rusage));
1005 lwkt_reltoken(&p->p_token);
1008 if ((options & WCONTINUED) && (p->p_flags & P_CONTINUED)) {
1009 lwkt_gettoken(&p->p_token);
1011 p->p_usched->heuristic_exiting(td->td_lwp, p);
1012 p->p_flags &= ~P_CONTINUED;
1017 lwkt_reltoken(&p->p_token);
1025 if (options & WNOHANG) {
1032 * Wait for signal - interlocked using q->p_token.
1034 error = tsleep(q, PCATCH, "wait", 0);
1037 lwkt_reltoken(&q->p_token);
1044 * Make process 'parent' the new parent of process 'child'.
1046 * p_children/p_sibling requires the parent's token, and
1047 * changing pptr requires the child's token, so we have to
1048 * get three tokens to do this operation.
1051 proc_reparent(struct proc *child, struct proc *parent)
1053 struct proc *opp = child->p_pptr;
1059 lwkt_gettoken(&opp->p_token);
1060 lwkt_gettoken(&child->p_token);
1061 lwkt_gettoken(&parent->p_token);
1062 KKASSERT(child->p_pptr == opp);
1063 LIST_REMOVE(child, p_sibling);
1064 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1065 child->p_pptr = parent;
1066 lwkt_reltoken(&parent->p_token);
1067 lwkt_reltoken(&child->p_token);
1068 lwkt_reltoken(&opp->p_token);
1074 * The next two functions are to handle adding/deleting items on the
1078 * Take the arguments given and put them onto the exit callout list,
1079 * However first make sure that it's not already there.
1080 * returns 0 on success.
1084 at_exit(exitlist_fn function)
1086 struct exitlist *ep;
1089 /* Be noisy if the programmer has lost track of things */
1090 if (rm_at_exit(function))
1091 kprintf("WARNING: exit callout entry (%p) already present\n",
1094 ep = kmalloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
1097 ep->function = function;
1098 TAILQ_INSERT_TAIL(&exit_list, ep, next);
1103 * Scan the exit callout list for the given item and remove it.
1104 * Returns the number of items removed (0 or 1)
1107 rm_at_exit(exitlist_fn function)
1109 struct exitlist *ep;
1111 TAILQ_FOREACH(ep, &exit_list, next) {
1112 if (ep->function == function) {
1113 TAILQ_REMOVE(&exit_list, ep, next);
1114 kfree(ep, M_ATEXIT);
1122 * LWP reaper related code.
1125 reaplwps(void *context, int dummy)
1127 struct lwplist *lwplist = context;
1130 lwkt_gettoken(&deadlwp_token);
1131 while ((lp = LIST_FIRST(lwplist))) {
1132 LIST_REMOVE(lp, u.lwp_reap_entry);
1135 lwkt_reltoken(&deadlwp_token);
1139 reaplwp(struct lwp *lp)
1141 while (lwp_wait(lp) == 0)
1151 for (cpu = 0; cpu < ncpus; cpu++) {
1152 LIST_INIT(&deadlwp_list[cpu]);
1153 deadlwp_task[cpu] = kmalloc(sizeof(*deadlwp_task[cpu]),
1154 M_DEVBUF, M_WAITOK);
1155 TASK_INIT(deadlwp_task[cpu], 0, reaplwps, &deadlwp_list[cpu]);
1159 SYSINIT(deadlwpinit, SI_SUB_CONFIGURE, SI_ORDER_ANY, deadlwp_init, NULL);