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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 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, notify process 1 instead (and hope it will handle
541 if (p->p_pptr->p_sigacts->ps_flag & PS_NOCLDWAIT) {
542 struct proc *pp = p->p_pptr;
545 proc_reparent(p, initproc);
548 * If this was the last child of our parent, notify
549 * parent, so in case he was wait(2)ing, he will
550 * continue. This function interlocks with pptr->p_token.
552 if (LIST_EMPTY(&pp->p_children))
557 /* lwkt_gettoken(&proc_token); */
560 if (p->p_sigparent && q != initproc) {
561 ksignal(q, p->p_sigparent);
566 p->p_flags &= ~P_TRACED;
570 /* lwkt_reltoken(&proc_token); */
571 /* NOTE: p->p_pptr can get ripped out */
573 * cpu_exit is responsible for clearing curproc, since
574 * it is heavily integrated with the thread/switching sequence.
576 * Other substructures are freed from wait().
581 * Release the current user process designation on the process so
582 * the userland scheduler can work in someone else.
584 p->p_usched->release_curproc(lp);
587 * Finally, call machine-dependent code to release as many of the
588 * lwp's resources as we can and halt execution of this thread.
594 * Eventually called by every exiting LWP
596 * p->p_token must be held. mplock may be held and will be released.
599 lwp_exit(int masterexit)
601 struct thread *td = curthread;
602 struct lwp *lp = td->td_lwp;
603 struct proc *p = lp->lwp_proc;
607 * lwp_exit() may be called without setting LWP_MP_WEXIT, so
608 * make sure it is set here.
610 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
611 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
614 * Clean up any virtualization
617 vkernel_lwp_exit(lp);
620 * Clean up select/poll support
622 kqueue_terminate(&lp->lwp_kqueue);
625 * Clean up any syscall-cached ucred
628 crfree(td->td_ucred);
633 * Nobody actually wakes us when the lock
634 * count reaches zero, so just wait one tick.
636 while (lp->lwp_lock > 0)
637 tsleep(lp, 0, "lwpexit", 1);
639 /* Hand down resource usage to our proc */
640 ruadd(&p->p_ru, &lp->lwp_ru);
643 * If we don't hold the process until the LWP is reaped wait*()
644 * may try to dispose of its vmspace before all the LWPs have
645 * actually terminated.
650 * Do any remaining work that might block on us. We should be
651 * coded such that further blocking is ok after decrementing
652 * p_nthreads but don't take the chance.
654 dsched_exit_thread(td);
655 biosched_done(curthread);
658 * We have to use the reaper for all the LWPs except the one doing
659 * the master exit. The LWP doing the master exit can just be
660 * left on p_lwps and the process reaper will deal with it
661 * synchronously, which is much faster.
663 * Wakeup anyone waiting on p_nthreads to drop to 1 or 0.
665 * The process is left held until the reaper calls lwp_dispose() on
666 * the lp (after calling lwp_wait()).
668 if (masterexit == 0) {
669 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
671 if (p->p_nthreads <= 1)
673 lwkt_gettoken(&deadlwp_token);
674 LIST_INSERT_HEAD(&deadlwp_list[mycpuid], lp, u.lwp_reap_entry);
675 taskqueue_enqueue(taskqueue_thread[mycpuid],
676 deadlwp_task[mycpuid]);
677 lwkt_reltoken(&deadlwp_token);
680 if (p->p_nthreads <= 1)
685 * Release p_token. Issue the wakeup() on p_nthreads if necessary,
686 * as late as possible to give us a chance to actually deschedule and
687 * switch away before another cpu core hits reaplwp().
689 lwkt_reltoken(&p->p_token);
691 wakeup(&p->p_nthreads);
696 * Wait until a lwp is completely dead. The final interlock in this drama
697 * is when TDF_EXITING is set in cpu_thread_exit() just before the final
700 * At the point TDF_EXITING is set a complete exit is accomplished when
701 * TDF_RUNNING and TDF_PREEMPT_LOCK are both clear.
703 * Returns non-zero on success, and zero if the caller needs to retry
707 lwp_wait(struct lwp *lp)
709 struct thread *td = lp->lwp_thread;;
711 KKASSERT(lwkt_preempted_proc() != lp);
714 * Wait until the lp has entered its low level exit and wait
715 * until other cores with refs on the lp (e.g. for ps or signaling)
718 if (lp->lwp_lock > 0) {
719 tsleep(lp, 0, "lwpwait1", 1);
724 * Wait until the thread is no longer references and no longer
725 * runnable or preempted (i.e. finishes its low level exit).
728 tsleep(td, 0, "lwpwait2", 1);
733 * The lwp's thread may still be in the middle
734 * of switching away, we can't rip its stack out from
735 * under it until TDF_EXITING is set and both
736 * TDF_RUNNING and TDF_PREEMPT_LOCK are clear.
737 * TDF_PREEMPT_LOCK must be checked because TDF_RUNNING
738 * will be cleared temporarily if a thread gets
741 * YYY no wakeup occurs, so we simply return failure
742 * and let the caller deal with sleeping and calling
745 if ((td->td_flags & (TDF_RUNNING |
747 TDF_EXITING)) != TDF_EXITING) {
748 tsleep(lp, 0, "lwpwait2", 1);
751 KASSERT((td->td_flags & (TDF_RUNQ|TDF_TSLEEPQ)) == 0,
752 ("lwp_wait: td %p (%s) still on run or sleep queue",
758 * Release the resources associated with a lwp.
759 * The lwp must be completely dead.
762 lwp_dispose(struct lwp *lp)
764 struct thread *td = lp->lwp_thread;;
766 KKASSERT(lwkt_preempted_proc() != lp);
767 KKASSERT(td->td_refs == 0);
768 KKASSERT((td->td_flags & (TDF_RUNNING |
770 TDF_EXITING)) == TDF_EXITING);
777 lp->lwp_thread = NULL;
778 lwkt_free_thread(td);
787 sys_wait4(struct wait_args *uap)
789 struct rusage rusage;
792 error = kern_wait(uap->pid, (uap->status ? &status : NULL),
793 uap->options, (uap->rusage ? &rusage : NULL),
794 &uap->sysmsg_result);
796 if (error == 0 && uap->status)
797 error = copyout(&status, uap->status, sizeof(*uap->status));
798 if (error == 0 && uap->rusage)
799 error = copyout(&rusage, uap->rusage, sizeof(*uap->rusage));
806 * wait_args(int pid, int *status, int options, struct rusage *rusage)
811 kern_wait(pid_t pid, int *status, int options, struct rusage *rusage, int *res)
813 struct thread *td = curthread;
815 struct proc *q = td->td_proc;
823 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
826 lwkt_gettoken(&q->p_token);
829 * All sorts of things can change due to blocking so we have to loop
830 * all the way back up here.
832 * The problem is that if a process group is stopped and the parent
833 * is doing a wait*(..., WUNTRACED, ...), it will see the STOP
834 * of the child and then stop itself when it tries to return from the
835 * system call. When the process group is resumed the parent will
836 * then get the STOP status even though the child has now resumed
837 * (a followup wait*() will get the CONT status).
839 * Previously the CONT would overwrite the STOP because the tstop
840 * was handled within tsleep(), and the parent would only see
841 * the CONT when both are stopped and continued together. This little
842 * two-line hack restores this effect.
844 while (q->p_stat == SSTOP)
852 * NOTE: We don't want to break q's p_token in the loop for the
853 * case where no children are found or we risk breaking the
854 * interlock between child and parent.
856 LIST_FOREACH(p, &q->p_children, p_sibling) {
857 if (pid != WAIT_ANY &&
858 p->p_pid != pid && p->p_pgid != -pid) {
863 * This special case handles a kthread spawned by linux_clone
864 * (see linux_misc.c). The linux_wait4 and linux_waitpid
865 * functions need to be able to distinguish between waiting
866 * on a process and waiting on a thread. It is a thread if
867 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
868 * signifies we want to wait for threads and not processes.
870 if ((p->p_sigparent != SIGCHLD) ^
871 ((options & WLINUXCLONE) != 0)) {
876 if (p->p_stat == SZOMB) {
878 * We may go into SZOMB with threads still present.
879 * We must wait for them to exit before we can reap
880 * the master thread, otherwise we may race reaping
881 * non-master threads.
883 lwkt_gettoken(&p->p_token);
884 while (p->p_nthreads > 0) {
885 tsleep(&p->p_nthreads, 0, "lwpzomb", hz);
889 * Reap any LWPs left in p->p_lwps. This is usually
890 * just the last LWP. This must be done before
891 * we loop on p_lock since the lwps hold a ref on
892 * it as a vmspace interlock.
894 * Once that is accomplished p_nthreads had better
897 while ((lp = RB_ROOT(&p->p_lwp_tree)) != NULL) {
898 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
901 KKASSERT(p->p_nthreads == 0);
904 * Don't do anything really bad until all references
905 * to the process go away. This may include other
906 * LWPs which are still in the process of being
907 * reaped. We can't just pull the rug out from under
908 * them because they may still be using the VM space.
910 * Certain kernel facilities such as /proc will also
911 * put a hold on the process for short periods of
914 PSTALL(p, "reap3", 0);
916 /* Take care of our return values. */
918 p->p_usched->heuristic_exiting(td->td_lwp, p);
921 *status = p->p_xstat;
925 * If we got the child via a ptrace 'attach',
926 * we need to give it back to the old parent.
928 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
935 lwkt_reltoken(&p->p_token);
940 * Unlink the proc from its process group so that
941 * the following operations won't lead to an
942 * inconsistent state for processes running down
945 proc_remove_zombie(p);
946 lwkt_reltoken(&p->p_token);
950 ruadd(&q->p_cru, &p->p_ru);
953 * Decrement the count of procs running with this uid.
955 chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
958 * Free up credentials.
964 * Remove unused arguments
968 if (pa && refcount_release(&pa->ar_ref)) {
975 if (ps && refcount_release(&ps->ps_refcnt)) {
976 kfree(ps, M_SUBPROC);
981 * Our exitingcount was incremented when the process
982 * became a zombie, now that the process has been
983 * removed from (almost) all lists we should be able
984 * to safely destroy its vmspace. Wait for any current
985 * holders to go away (so the vmspace remains stable),
988 PSTALL(p, "reap4", 0);
990 PSTALL(p, "reap5", 0);
993 atomic_add_int(&nprocs, -1);
997 if (p->p_stat == SSTOP && (p->p_flags & P_WAITED) == 0 &&
998 ((p->p_flags & P_TRACED) || (options & WUNTRACED))) {
999 lwkt_gettoken(&p->p_token);
1000 p->p_flags |= P_WAITED;
1003 p->p_usched->heuristic_exiting(td->td_lwp, p);
1005 *status = W_STOPCODE(p->p_xstat);
1006 /* Zero rusage so we get something consistent. */
1008 bzero(rusage, sizeof(rusage));
1010 lwkt_reltoken(&p->p_token);
1013 if ((options & WCONTINUED) && (p->p_flags & P_CONTINUED)) {
1014 lwkt_gettoken(&p->p_token);
1016 p->p_usched->heuristic_exiting(td->td_lwp, p);
1017 p->p_flags &= ~P_CONTINUED;
1022 lwkt_reltoken(&p->p_token);
1030 if (options & WNOHANG) {
1037 * Wait for signal - interlocked using q->p_token.
1039 error = tsleep(q, PCATCH, "wait", 0);
1042 lwkt_reltoken(&q->p_token);
1049 * Make process 'parent' the new parent of process 'child'.
1051 * p_children/p_sibling requires the parent's token, and
1052 * changing pptr requires the child's token, so we have to
1053 * get three tokens to do this operation.
1056 proc_reparent(struct proc *child, struct proc *parent)
1058 struct proc *opp = child->p_pptr;
1064 lwkt_gettoken(&opp->p_token);
1065 lwkt_gettoken(&child->p_token);
1066 lwkt_gettoken(&parent->p_token);
1067 KKASSERT(child->p_pptr == opp);
1068 LIST_REMOVE(child, p_sibling);
1069 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1070 child->p_pptr = parent;
1071 lwkt_reltoken(&parent->p_token);
1072 lwkt_reltoken(&child->p_token);
1073 lwkt_reltoken(&opp->p_token);
1079 * The next two functions are to handle adding/deleting items on the
1083 * Take the arguments given and put them onto the exit callout list,
1084 * However first make sure that it's not already there.
1085 * returns 0 on success.
1089 at_exit(exitlist_fn function)
1091 struct exitlist *ep;
1094 /* Be noisy if the programmer has lost track of things */
1095 if (rm_at_exit(function))
1096 kprintf("WARNING: exit callout entry (%p) already present\n",
1099 ep = kmalloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
1102 ep->function = function;
1103 TAILQ_INSERT_TAIL(&exit_list, ep, next);
1108 * Scan the exit callout list for the given item and remove it.
1109 * Returns the number of items removed (0 or 1)
1112 rm_at_exit(exitlist_fn function)
1114 struct exitlist *ep;
1116 TAILQ_FOREACH(ep, &exit_list, next) {
1117 if (ep->function == function) {
1118 TAILQ_REMOVE(&exit_list, ep, next);
1119 kfree(ep, M_ATEXIT);
1127 * LWP reaper related code.
1130 reaplwps(void *context, int dummy)
1132 struct lwplist *lwplist = context;
1135 lwkt_gettoken(&deadlwp_token);
1136 while ((lp = LIST_FIRST(lwplist))) {
1137 LIST_REMOVE(lp, u.lwp_reap_entry);
1140 lwkt_reltoken(&deadlwp_token);
1144 reaplwp(struct lwp *lp)
1146 while (lwp_wait(lp) == 0)
1156 for (cpu = 0; cpu < ncpus; cpu++) {
1157 LIST_INIT(&deadlwp_list[cpu]);
1158 deadlwp_task[cpu] = kmalloc(sizeof(*deadlwp_task[cpu]),
1159 M_DEVBUF, M_WAITOK);
1160 TASK_INIT(deadlwp_task[cpu], 0, reaplwps, &deadlwp_list[cpu]);
1164 SYSINIT(deadlwpinit, SI_SUB_CONFIGURE, SI_ORDER_ANY, deadlwp_init, NULL);