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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 $
42 #include "opt_compat.h"
43 #include "opt_ktrace.h"
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
51 #include <sys/ktrace.h>
52 #include <sys/pioctl.h>
55 #include <sys/vnode.h>
56 #include <sys/resourcevar.h>
57 #include <sys/signalvar.h>
58 #include <sys/taskqueue.h>
59 #include <sys/ptrace.h>
60 #include <sys/acct.h> /* for acct_process() function prototype */
61 #include <sys/filedesc.h>
65 #include <sys/kern_syscall.h>
66 #include <sys/upcall.h>
67 #include <sys/unistd.h>
68 #include <sys/eventhandler.h>
69 #include <sys/dsched.h>
72 #include <vm/vm_param.h>
75 #include <vm/vm_map.h>
76 #include <vm/vm_extern.h>
79 #include <sys/refcount.h>
80 #include <sys/thread2.h>
81 #include <sys/sysref2.h>
82 #include <sys/mplock2.h>
84 static void reaplwps(void *context, int dummy);
85 static void reaplwp(struct lwp *lp);
86 static void killlwps(struct lwp *lp);
88 static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
89 static MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
91 static struct lwkt_token deadlwp_token = LWKT_TOKEN_INITIALIZER(deadlwp_token);
94 * callout list for things to do at exit time
98 TAILQ_ENTRY(exitlist) next;
101 TAILQ_HEAD(exit_list_head, exitlist);
102 static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
107 struct task *deadlwp_task[MAXCPU];
108 struct lwplist deadlwp_list[MAXCPU];
114 * SYS_EXIT_ARGS(int rval)
117 sys_exit(struct exit_args *uap)
119 exit1(W_EXITCODE(uap->rval, 0));
125 * Death of a lwp or process with optional bells and whistles.
130 sys_extexit(struct extexit_args *uap)
132 struct proc *p = curproc;
136 action = EXTEXIT_ACTION(uap->how);
137 who = EXTEXIT_WHO(uap->how);
139 /* Check parameters before we might perform some action */
152 error = copyout(&uap->status, uap->addr, sizeof(uap->status));
160 lwkt_gettoken(&p->p_token);
165 * Be sure only to perform a simple lwp exit if there is at
166 * least one more lwp in the proc, which will call exit1()
167 * later, otherwise the proc will be an UNDEAD and not even a
170 if (p->p_nthreads > 1) {
171 lwp_exit(0); /* called w/ p_token held */
174 /* else last lwp in proc: do the real thing */
176 default: /* to help gcc */
178 lwkt_reltoken(&p->p_token);
179 exit1(W_EXITCODE(uap->status, 0));
184 lwkt_reltoken(&p->p_token); /* safety */
188 * Kill all lwps associated with the current process except the
189 * current lwp. Return an error if we race another thread trying to
190 * do the same thing and lose the race.
192 * If forexec is non-zero the current thread and process flags are
193 * cleaned up so they can be reused.
195 * Caller must hold curproc->p_token
198 killalllwps(int forexec)
200 struct lwp *lp = curthread->td_lwp;
201 struct proc *p = lp->lwp_proc;
204 * Interlock against P_WEXIT. Only one of the process's thread
205 * is allowed to do the master exit.
207 if (p->p_flags & P_WEXIT)
209 p->p_flags |= P_WEXIT;
212 * Interlock with LWP_MP_WEXIT and kill any remaining LWPs
214 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
215 if (p->p_nthreads > 1)
219 * If doing this for an exec, clean up the remaining thread
220 * (us) for continuing operation after all the other threads
224 atomic_clear_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
225 p->p_flags &= ~P_WEXIT;
231 * Kill all LWPs except the current one. Do not try to signal
232 * LWPs which have exited on their own or have already been
236 killlwps(struct lwp *lp)
238 struct proc *p = lp->lwp_proc;
242 * Kill the remaining LWPs. We must send the signal before setting
243 * LWP_MP_WEXIT. The setting of WEXIT is optional but helps reduce
244 * races. tlp must be held across the call as it might block and
245 * allow the target lwp to rip itself out from under our loop.
247 FOREACH_LWP_IN_PROC(tlp, p) {
249 lwkt_gettoken(&tlp->lwp_token);
250 if ((tlp->lwp_mpflags & LWP_MP_WEXIT) == 0) {
251 lwpsignal(p, tlp, SIGKILL);
252 atomic_set_int(&tlp->lwp_mpflags, LWP_MP_WEXIT);
254 lwkt_reltoken(&tlp->lwp_token);
259 * Wait for everything to clear out.
261 while (p->p_nthreads > 1) {
262 tsleep(&p->p_nthreads, 0, "killlwps", 0);
267 * Exit: deallocate address space and other resources, change proc state
268 * to zombie, and unlink proc from allproc and parent's lists. Save exit
269 * status and rusage for wait(). Check for child processes and orphan them.
274 struct thread *td = curthread;
275 struct proc *p = td->td_proc;
276 struct lwp *lp = td->td_lwp;
283 lwkt_gettoken(&p->p_token);
286 kprintf("init died (signal %d, exit %d)\n",
287 WTERMSIG(rv), WEXITSTATUS(rv));
288 panic("Going nowhere without my init!");
290 varsymset_clean(&p->p_varsymset);
291 lockuninit(&p->p_varsymset.vx_lock);
294 * Kill all lwps associated with the current process, return an
295 * error if we race another thread trying to do the same thing
298 error = killalllwps(0);
304 /* are we a task leader? */
305 if (p == p->p_leader) {
306 struct kill_args killArgs;
307 killArgs.signum = SIGKILL;
310 killArgs.pid = q->p_pid;
312 * The interface for kill is better
313 * than the internal signal
320 tsleep((caddr_t)p, 0, "exit1", 0);
326 STOPEVENT(p, S_EXIT, rv);
327 p->p_flags |= P_POSTEXIT; /* stop procfs stepping */
330 * Check if any loadable modules need anything done at process exit.
331 * e.g. SYSV IPC stuff
332 * XXX what if one of these generates an error?
335 EVENTHANDLER_INVOKE(process_exit, p);
338 * XXX: imho, the eventhandler stuff is much cleaner than this.
339 * Maybe we should move everything to use eventhandler.
341 TAILQ_FOREACH(ep, &exit_list, next)
344 if (p->p_flags & P_PROFIL)
347 SIGEMPTYSET(p->p_siglist);
348 SIGEMPTYSET(lp->lwp_siglist);
349 if (timevalisset(&p->p_realtimer.it_value))
350 callout_stop_sync(&p->p_ithandle);
353 * Reset any sigio structures pointing to us as a result of
354 * F_SETOWN with our pid.
356 funsetownlst(&p->p_sigiolst);
359 * Close open files and release open-file table.
364 if(p->p_leader->p_peers) {
366 while(q->p_peers != p)
368 q->p_peers = p->p_peers;
369 wakeup((caddr_t)p->p_leader);
373 * XXX Shutdown SYSV semaphores
377 KKASSERT(p->p_numposixlocks == 0);
379 /* The next two chunks should probably be moved to vmspace_exit. */
383 * Release upcalls associated with this process
389 * Clean up data related to virtual kernel operation. Clean up
390 * any vkernel context related to the current lwp now so we can
394 vkernel_lwp_exit(lp);
399 * Release user portion of address space.
400 * This releases references to vnodes,
401 * which could cause I/O if the file has been unlinked.
402 * Need to do this early enough that we can still sleep.
403 * Can't free the entire vmspace as the kernel stack
404 * may be mapped within that space also.
406 * Processes sharing the same vmspace may exit in one order, and
407 * get cleaned up by vmspace_exit() in a different order. The
408 * last exiting process to reach this point releases as much of
409 * the environment as it can, and the last process cleaned up
410 * by vmspace_exit() (which decrements exitingcnt) cleans up the
413 vmspace_exitbump(vm);
414 sysref_put(&vm->vm_sysref);
416 if (SESS_LEADER(p)) {
417 struct session *sp = p->p_session;
421 * We are the controlling process. Signal the
422 * foreground process group, drain the controlling
423 * terminal, and revoke access to the controlling
426 * NOTE: while waiting for the process group to exit
427 * it is possible that one of the processes in the
428 * group will revoke the tty, so the ttyclosesession()
429 * function will re-check sp->s_ttyvp.
431 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
432 if (sp->s_ttyp->t_pgrp)
433 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
435 ttyclosesession(sp, 1); /* also revoke */
438 * Release the tty. If someone has it open via
439 * /dev/tty then close it (since they no longer can
440 * once we've NULL'd it out).
442 ttyclosesession(sp, 0);
445 * s_ttyp is not zero'd; we use this to indicate
446 * that the session once had a controlling terminal.
447 * (for logging and informational purposes)
452 fixjobc(p, p->p_pgrp, 0);
453 (void)acct_process(p);
459 ktrdestroy(&p->p_tracenode);
463 * Release reference to text vnode
465 if ((vtmp = p->p_textvp) != NULL) {
470 /* Release namecache handle to text file */
471 if (p->p_textnch.ncp)
472 cache_drop(&p->p_textnch);
475 * We have to handle PPWAIT here or proc_move_allproc_zombie()
476 * will block on the PHOLD() the parent is doing.
478 if (p->p_flags & P_PPWAIT) {
479 p->p_flags &= ~P_PPWAIT;
484 * Move the process to the zombie list. This will block
485 * until the process p_lock count reaches 0. The process will
486 * not be reaped until TDF_EXITING is set by cpu_thread_exit(),
487 * which is called from cpu_proc_exit().
489 proc_move_allproc_zombie(p);
492 * Reparent all of this process's children to the init process.
493 * We must hold initproc->p_token in order to mess with
494 * initproc->p_children. We already hold p->p_token (to remove
495 * the children from our list).
497 q = LIST_FIRST(&p->p_children);
499 lwkt_gettoken(&initproc->p_token);
500 while ((q = LIST_FIRST(&p->p_children)) != NULL) {
502 lwkt_gettoken(&q->p_token);
503 if (q != LIST_FIRST(&p->p_children)) {
504 lwkt_reltoken(&q->p_token);
508 LIST_REMOVE(q, p_sibling);
509 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling);
510 q->p_pptr = initproc;
511 q->p_sigparent = SIGCHLD;
514 * Traced processes are killed
515 * since their existence means someone is screwing up.
517 if (q->p_flags & P_TRACED) {
518 q->p_flags &= ~P_TRACED;
521 lwkt_reltoken(&q->p_token);
524 lwkt_reltoken(&initproc->p_token);
529 * Save exit status and final rusage info, adding in child rusage
530 * info and self times.
532 calcru_proc(p, &p->p_ru);
533 ruadd(&p->p_ru, &p->p_cru);
536 * notify interested parties of our demise.
538 KNOTE(&p->p_klist, NOTE_EXIT);
541 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
542 * flag set, or if the handler is set to SIG_IGN, notify process 1
543 * instead (and hope it will handle this situation).
545 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
546 struct proc *pp = p->p_pptr;
549 proc_reparent(p, initproc);
552 * If this was the last child of our parent, notify
553 * parent, so in case he was wait(2)ing, he will
554 * continue. This function interlocks with pptr->p_token.
556 if (LIST_EMPTY(&pp->p_children))
561 /* lwkt_gettoken(&proc_token); */
564 if (p->p_sigparent && q != initproc) {
565 ksignal(q, p->p_sigparent);
570 p->p_flags &= ~P_TRACED;
574 /* lwkt_reltoken(&proc_token); */
575 /* NOTE: p->p_pptr can get ripped out */
577 * cpu_exit is responsible for clearing curproc, since
578 * it is heavily integrated with the thread/switching sequence.
580 * Other substructures are freed from wait().
585 * Release the current user process designation on the process so
586 * the userland scheduler can work in someone else.
588 p->p_usched->release_curproc(lp);
591 * Finally, call machine-dependent code to release as many of the
592 * lwp's resources as we can and halt execution of this thread.
598 * Eventually called by every exiting LWP
600 * p->p_token must be held. mplock may be held and will be released.
603 lwp_exit(int masterexit)
605 struct thread *td = curthread;
606 struct lwp *lp = td->td_lwp;
607 struct proc *p = lp->lwp_proc;
611 * lwp_exit() may be called without setting LWP_MP_WEXIT, so
612 * make sure it is set here.
614 ASSERT_LWKT_TOKEN_HELD(&p->p_token);
615 atomic_set_int(&lp->lwp_mpflags, LWP_MP_WEXIT);
618 * Clean up any virtualization
621 vkernel_lwp_exit(lp);
624 * Clean up select/poll support
626 kqueue_terminate(&lp->lwp_kqueue);
629 * Clean up any syscall-cached ucred
632 crfree(td->td_ucred);
637 * Nobody actually wakes us when the lock
638 * count reaches zero, so just wait one tick.
640 while (lp->lwp_lock > 0)
641 tsleep(lp, 0, "lwpexit", 1);
643 /* Hand down resource usage to our proc */
644 ruadd(&p->p_ru, &lp->lwp_ru);
647 * If we don't hold the process until the LWP is reaped wait*()
648 * may try to dispose of its vmspace before all the LWPs have
649 * actually terminated.
654 * Do any remaining work that might block on us. We should be
655 * coded such that further blocking is ok after decrementing
656 * p_nthreads but don't take the chance.
658 dsched_exit_thread(td);
659 biosched_done(curthread);
662 * We have to use the reaper for all the LWPs except the one doing
663 * the master exit. The LWP doing the master exit can just be
664 * left on p_lwps and the process reaper will deal with it
665 * synchronously, which is much faster.
667 * Wakeup anyone waiting on p_nthreads to drop to 1 or 0.
669 * The process is left held until the reaper calls lwp_dispose() on
670 * the lp (after calling lwp_wait()).
672 if (masterexit == 0) {
673 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
675 if (p->p_nthreads <= 1)
677 lwkt_gettoken(&deadlwp_token);
678 LIST_INSERT_HEAD(&deadlwp_list[mycpuid], lp, u.lwp_reap_entry);
679 taskqueue_enqueue(taskqueue_thread[mycpuid],
680 deadlwp_task[mycpuid]);
681 lwkt_reltoken(&deadlwp_token);
684 if (p->p_nthreads <= 1)
689 * Release p_token. Issue the wakeup() on p_nthreads if necessary,
690 * as late as possible to give us a chance to actually deschedule and
691 * switch away before another cpu core hits reaplwp().
693 lwkt_reltoken(&p->p_token);
695 wakeup(&p->p_nthreads);
698 * Tell the userland scheduler that we are going away
700 p->p_usched->heuristic_exiting(lp, p);
706 * Wait until a lwp is completely dead. The final interlock in this drama
707 * is when TDF_EXITING is set in cpu_thread_exit() just before the final
710 * At the point TDF_EXITING is set a complete exit is accomplished when
711 * TDF_RUNNING and TDF_PREEMPT_LOCK are both clear. td_mpflags has two
712 * post-switch interlock flags that can be used to wait for the TDF_
715 * Returns non-zero on success, and zero if the caller needs to retry
719 lwp_wait(struct lwp *lp)
721 struct thread *td = lp->lwp_thread;;
724 KKASSERT(lwkt_preempted_proc() != lp);
727 * This bit of code uses the thread destruction interlock
728 * managed by lwkt_switch_return() to wait for the lwp's
729 * thread to completely disengage.
731 * It is possible for us to race another cpu core so we
732 * have to do this correctly.
735 mpflags = td->td_mpflags;
737 if (mpflags & TDF_MP_EXITSIG)
739 tsleep_interlock(td, 0);
740 if (atomic_cmpset_int(&td->td_mpflags, mpflags,
741 mpflags | TDF_MP_EXITWAIT)) {
742 tsleep(td, PINTERLOCKED, "lwpxt", 0);
747 * We've already waited for the core exit but there can still
748 * be other refs from e.g. process scans and such.
750 if (lp->lwp_lock > 0) {
751 tsleep(lp, 0, "lwpwait1", 1);
755 tsleep(td, 0, "lwpwait2", 1);
760 * Now that we have the thread destruction interlock these flags
761 * really should already be cleaned up, keep a check for safety.
763 * We can't rip its stack out from under it until TDF_EXITING is
764 * set and both TDF_RUNNING and TDF_PREEMPT_LOCK are clear.
765 * TDF_PREEMPT_LOCK must be checked because TDF_RUNNING
766 * will be cleared temporarily if a thread gets preempted.
768 while ((td->td_flags & (TDF_RUNNING |
770 TDF_EXITING)) != TDF_EXITING) {
771 tsleep(lp, 0, "lwpwait3", 1);
775 KASSERT((td->td_flags & (TDF_RUNQ|TDF_TSLEEPQ)) == 0,
776 ("lwp_wait: td %p (%s) still on run or sleep queue",
782 * Release the resources associated with a lwp.
783 * The lwp must be completely dead.
786 lwp_dispose(struct lwp *lp)
788 struct thread *td = lp->lwp_thread;;
790 KKASSERT(lwkt_preempted_proc() != lp);
791 KKASSERT(td->td_refs == 0);
792 KKASSERT((td->td_flags & (TDF_RUNNING |
794 TDF_EXITING)) == TDF_EXITING);
801 lp->lwp_thread = NULL;
802 lwkt_free_thread(td);
811 sys_wait4(struct wait_args *uap)
813 struct rusage rusage;
816 error = kern_wait(uap->pid, (uap->status ? &status : NULL),
817 uap->options, (uap->rusage ? &rusage : NULL),
818 &uap->sysmsg_result);
820 if (error == 0 && uap->status)
821 error = copyout(&status, uap->status, sizeof(*uap->status));
822 if (error == 0 && uap->rusage)
823 error = copyout(&rusage, uap->rusage, sizeof(*uap->rusage));
830 * wait_args(int pid, int *status, int options, struct rusage *rusage)
835 kern_wait(pid_t pid, int *status, int options, struct rusage *rusage, int *res)
837 struct thread *td = curthread;
839 struct proc *q = td->td_proc;
847 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
850 lwkt_gettoken(&q->p_token);
853 * All sorts of things can change due to blocking so we have to loop
854 * all the way back up here.
856 * The problem is that if a process group is stopped and the parent
857 * is doing a wait*(..., WUNTRACED, ...), it will see the STOP
858 * of the child and then stop itself when it tries to return from the
859 * system call. When the process group is resumed the parent will
860 * then get the STOP status even though the child has now resumed
861 * (a followup wait*() will get the CONT status).
863 * Previously the CONT would overwrite the STOP because the tstop
864 * was handled within tsleep(), and the parent would only see
865 * the CONT when both are stopped and continued together. This little
866 * two-line hack restores this effect.
868 while (q->p_stat == SSTOP)
876 * NOTE: We don't want to break q's p_token in the loop for the
877 * case where no children are found or we risk breaking the
878 * interlock between child and parent.
880 LIST_FOREACH(p, &q->p_children, p_sibling) {
881 if (pid != WAIT_ANY &&
882 p->p_pid != pid && p->p_pgid != -pid) {
887 * This special case handles a kthread spawned by linux_clone
888 * (see linux_misc.c). The linux_wait4 and linux_waitpid
889 * functions need to be able to distinguish between waiting
890 * on a process and waiting on a thread. It is a thread if
891 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
892 * signifies we want to wait for threads and not processes.
894 if ((p->p_sigparent != SIGCHLD) ^
895 ((options & WLINUXCLONE) != 0)) {
900 if (p->p_stat == SZOMB) {
902 * We may go into SZOMB with threads still present.
903 * We must wait for them to exit before we can reap
904 * the master thread, otherwise we may race reaping
905 * non-master threads.
907 * Only this routine can remove a process from
908 * the zombie list and destroy it, use PACQUIREZOMB()
909 * to serialize us and loop if it blocks (interlocked
910 * by the parent's q->p_token).
912 * WARNING! (p) can be invalid when PHOLDZOMB(p)
913 * returns non-zero. Be sure not to
918 lwkt_gettoken(&p->p_token);
919 if (p->p_pptr != q) {
920 lwkt_reltoken(&p->p_token);
924 while (p->p_nthreads > 0) {
925 tsleep(&p->p_nthreads, 0, "lwpzomb", hz);
929 * Reap any LWPs left in p->p_lwps. This is usually
930 * just the last LWP. This must be done before
931 * we loop on p_lock since the lwps hold a ref on
932 * it as a vmspace interlock.
934 * Once that is accomplished p_nthreads had better
937 while ((lp = RB_ROOT(&p->p_lwp_tree)) != NULL) {
938 lwp_rb_tree_RB_REMOVE(&p->p_lwp_tree, lp);
941 KKASSERT(p->p_nthreads == 0);
944 * Don't do anything really bad until all references
945 * to the process go away. This may include other
946 * LWPs which are still in the process of being
947 * reaped. We can't just pull the rug out from under
948 * them because they may still be using the VM space.
950 * Certain kernel facilities such as /proc will also
951 * put a hold on the process for short periods of
955 PSTALL(p, "reap3", 0);
957 /* Take care of our return values. */
961 *status = p->p_xstat;
965 * If we got the child via a ptrace 'attach',
966 * we need to give it back to the old parent.
968 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
976 lwkt_reltoken(&p->p_token);
982 * Unlink the proc from its process group so that
983 * the following operations won't lead to an
984 * inconsistent state for processes running down
987 proc_remove_zombie(p);
988 lwkt_reltoken(&p->p_token);
992 ruadd(&q->p_cru, &p->p_ru);
995 * Decrement the count of procs running with this uid.
997 chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
1000 * Free up credentials.
1006 * Remove unused arguments
1010 if (pa && refcount_release(&pa->ar_ref)) {
1016 p->p_sigacts = NULL;
1017 if (ps && refcount_release(&ps->ps_refcnt)) {
1018 kfree(ps, M_SUBPROC);
1023 * Our exitingcount was incremented when the process
1024 * became a zombie, now that the process has been
1025 * removed from (almost) all lists we should be able
1026 * to safely destroy its vmspace. Wait for any current
1027 * holders to go away (so the vmspace remains stable),
1030 PSTALL(p, "reap4", 0);
1031 vmspace_exitfree(p);
1032 PSTALL(p, "reap5", 0);
1035 * NOTE: We have to officially release ZOMB in order
1036 * to ensure that a racing thread in kern_wait()
1037 * which blocked on ZOMB is woken up.
1042 atomic_add_int(&nprocs, -1);
1046 if (p->p_stat == SSTOP && (p->p_flags & P_WAITED) == 0 &&
1047 ((p->p_flags & P_TRACED) || (options & WUNTRACED))) {
1049 lwkt_gettoken(&p->p_token);
1050 if (p->p_pptr != q) {
1051 lwkt_reltoken(&p->p_token);
1055 if (p->p_stat != SSTOP ||
1056 (p->p_flags & P_WAITED) != 0 ||
1057 ((p->p_flags & P_TRACED) == 0 &&
1058 (options & WUNTRACED) == 0)) {
1059 lwkt_reltoken(&p->p_token);
1064 p->p_flags |= P_WAITED;
1068 *status = W_STOPCODE(p->p_xstat);
1069 /* Zero rusage so we get something consistent. */
1071 bzero(rusage, sizeof(*rusage));
1073 lwkt_reltoken(&p->p_token);
1077 if ((options & WCONTINUED) && (p->p_flags & P_CONTINUED)) {
1079 lwkt_gettoken(&p->p_token);
1080 if (p->p_pptr != q) {
1081 lwkt_reltoken(&p->p_token);
1085 if ((p->p_flags & P_CONTINUED) == 0) {
1086 lwkt_reltoken(&p->p_token);
1092 p->p_flags &= ~P_CONTINUED;
1097 lwkt_reltoken(&p->p_token);
1106 if (options & WNOHANG) {
1113 * Wait for signal - interlocked using q->p_token.
1115 error = tsleep(q, PCATCH, "wait", 0);
1118 lwkt_reltoken(&q->p_token);
1125 * Make process 'parent' the new parent of process 'child'.
1127 * p_children/p_sibling requires the parent's token, and
1128 * changing pptr requires the child's token, so we have to
1129 * get three tokens to do this operation.
1132 proc_reparent(struct proc *child, struct proc *parent)
1134 struct proc *opp = child->p_pptr;
1140 lwkt_gettoken(&opp->p_token);
1141 lwkt_gettoken(&child->p_token);
1142 lwkt_gettoken(&parent->p_token);
1143 KKASSERT(child->p_pptr == opp);
1144 LIST_REMOVE(child, p_sibling);
1145 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
1146 child->p_pptr = parent;
1147 lwkt_reltoken(&parent->p_token);
1148 lwkt_reltoken(&child->p_token);
1149 lwkt_reltoken(&opp->p_token);
1155 * The next two functions are to handle adding/deleting items on the
1159 * Take the arguments given and put them onto the exit callout list,
1160 * However first make sure that it's not already there.
1161 * returns 0 on success.
1165 at_exit(exitlist_fn function)
1167 struct exitlist *ep;
1170 /* Be noisy if the programmer has lost track of things */
1171 if (rm_at_exit(function))
1172 kprintf("WARNING: exit callout entry (%p) already present\n",
1175 ep = kmalloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
1178 ep->function = function;
1179 TAILQ_INSERT_TAIL(&exit_list, ep, next);
1184 * Scan the exit callout list for the given item and remove it.
1185 * Returns the number of items removed (0 or 1)
1188 rm_at_exit(exitlist_fn function)
1190 struct exitlist *ep;
1192 TAILQ_FOREACH(ep, &exit_list, next) {
1193 if (ep->function == function) {
1194 TAILQ_REMOVE(&exit_list, ep, next);
1195 kfree(ep, M_ATEXIT);
1203 * LWP reaper related code.
1206 reaplwps(void *context, int dummy)
1208 struct lwplist *lwplist = context;
1211 lwkt_gettoken(&deadlwp_token);
1212 while ((lp = LIST_FIRST(lwplist))) {
1213 LIST_REMOVE(lp, u.lwp_reap_entry);
1216 lwkt_reltoken(&deadlwp_token);
1220 reaplwp(struct lwp *lp)
1222 while (lwp_wait(lp) == 0)
1232 for (cpu = 0; cpu < ncpus; cpu++) {
1233 LIST_INIT(&deadlwp_list[cpu]);
1234 deadlwp_task[cpu] = kmalloc(sizeof(*deadlwp_task[cpu]),
1235 M_DEVBUF, M_WAITOK);
1236 TASK_INIT(deadlwp_task[cpu], 0, reaplwps, &deadlwp_list[cpu]);
1240 SYSINIT(deadlwpinit, SI_SUB_CONFIGURE, SI_ORDER_ANY, deadlwp_init, NULL);