2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
3 * Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org>
4 * Copyright (c) 2009 Apple, Inc.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include "opt_ktrace.h"
33 #include "opt_kqueue.h"
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/capsicum.h>
38 #include <sys/kernel.h>
40 #include <sys/mutex.h>
41 #include <sys/rwlock.h>
43 #include <sys/malloc.h>
44 #include <sys/unistd.h>
46 #include <sys/filedesc.h>
47 #include <sys/filio.h>
48 #include <sys/fcntl.h>
49 #include <sys/kthread.h>
50 #include <sys/selinfo.h>
51 #include <sys/stdatomic.h>
52 #include <sys/queue.h>
53 #include <sys/event.h>
54 #include <sys/eventvar.h>
56 #include <sys/protosw.h>
57 #include <sys/resourcevar.h>
58 #include <sys/sigio.h>
59 #include <sys/signalvar.h>
60 #include <sys/socket.h>
61 #include <sys/socketvar.h>
63 #include <sys/sysctl.h>
64 #include <sys/sysproto.h>
65 #include <sys/syscallsubr.h>
66 #include <sys/taskqueue.h>
70 #include <sys/ktrace.h>
75 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
78 * This lock is used if multiple kq locks are required. This possibly
79 * should be made into a per proc lock.
81 static struct mtx kq_global;
82 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF);
83 #define KQ_GLOBAL_LOCK(lck, haslck) do { \
88 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \
94 TASKQUEUE_DEFINE_THREAD(kqueue_ctx);
96 static int kevent_copyout(void *arg, struct kevent *kevp, int count);
97 static int kevent_copyin(void *arg, struct kevent *kevp, int count);
98 static int kqueue_register(struct kqueue *kq, struct kevent *kev,
99 struct thread *td, int waitok);
100 static int kqueue_acquire(struct file *fp, struct kqueue **kqp);
101 static void kqueue_release(struct kqueue *kq, int locked);
102 static void kqueue_destroy(struct kqueue *kq);
103 static void kqueue_drain(struct kqueue *kq, struct thread *td);
104 static int kqueue_expand(struct kqueue *kq, struct filterops *fops,
105 uintptr_t ident, int waitok);
106 static void kqueue_task(void *arg, int pending);
107 static int kqueue_scan(struct kqueue *kq, int maxevents,
108 struct kevent_copyops *k_ops,
109 const struct timespec *timeout,
110 struct kevent *keva, struct thread *td);
111 static void kqueue_wakeup(struct kqueue *kq);
112 static struct filterops *kqueue_fo_find(int filt);
113 static void kqueue_fo_release(int filt);
115 static fo_ioctl_t kqueue_ioctl;
116 static fo_poll_t kqueue_poll;
117 static fo_kqfilter_t kqueue_kqfilter;
118 static fo_stat_t kqueue_stat;
119 static fo_close_t kqueue_close;
120 static fo_fill_kinfo_t kqueue_fill_kinfo;
122 static struct fileops kqueueops = {
123 .fo_read = invfo_rdwr,
124 .fo_write = invfo_rdwr,
125 .fo_truncate = invfo_truncate,
126 .fo_ioctl = kqueue_ioctl,
127 .fo_poll = kqueue_poll,
128 .fo_kqfilter = kqueue_kqfilter,
129 .fo_stat = kqueue_stat,
130 .fo_close = kqueue_close,
131 .fo_chmod = invfo_chmod,
132 .fo_chown = invfo_chown,
133 .fo_sendfile = invfo_sendfile,
134 .fo_fill_kinfo = kqueue_fill_kinfo,
137 static int knote_attach(struct knote *kn, struct kqueue *kq);
138 static void knote_drop(struct knote *kn, struct thread *td);
139 static void knote_enqueue(struct knote *kn);
140 static void knote_dequeue(struct knote *kn);
141 static void knote_init(void);
142 static struct knote *knote_alloc(int waitok);
143 static void knote_free(struct knote *kn);
145 static void filt_kqdetach(struct knote *kn);
146 static int filt_kqueue(struct knote *kn, long hint);
147 static int filt_procattach(struct knote *kn);
148 static void filt_procdetach(struct knote *kn);
149 static int filt_proc(struct knote *kn, long hint);
150 static int filt_fileattach(struct knote *kn);
151 static void filt_timerexpire(void *knx);
152 static int filt_timerattach(struct knote *kn);
153 static void filt_timerdetach(struct knote *kn);
154 static int filt_timer(struct knote *kn, long hint);
155 static int filt_userattach(struct knote *kn);
156 static void filt_userdetach(struct knote *kn);
157 static int filt_user(struct knote *kn, long hint);
158 static void filt_usertouch(struct knote *kn, struct kevent *kev,
161 static struct filterops file_filtops = {
163 .f_attach = filt_fileattach,
165 static struct filterops kqread_filtops = {
167 .f_detach = filt_kqdetach,
168 .f_event = filt_kqueue,
170 /* XXX - move to kern_proc.c? */
171 static struct filterops proc_filtops = {
173 .f_attach = filt_procattach,
174 .f_detach = filt_procdetach,
175 .f_event = filt_proc,
177 static struct filterops timer_filtops = {
179 .f_attach = filt_timerattach,
180 .f_detach = filt_timerdetach,
181 .f_event = filt_timer,
183 static struct filterops user_filtops = {
184 .f_attach = filt_userattach,
185 .f_detach = filt_userdetach,
186 .f_event = filt_user,
187 .f_touch = filt_usertouch,
190 static uma_zone_t knote_zone;
191 static atomic_uint kq_ncallouts = ATOMIC_VAR_INIT(0);
192 static unsigned int kq_calloutmax = 4 * 1024;
193 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
194 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
196 /* XXX - ensure not KN_INFLUX?? */
197 #define KNOTE_ACTIVATE(kn, islock) do { \
199 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \
201 KQ_LOCK((kn)->kn_kq); \
202 (kn)->kn_status |= KN_ACTIVE; \
203 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
204 knote_enqueue((kn)); \
206 KQ_UNLOCK((kn)->kn_kq); \
208 #define KQ_LOCK(kq) do { \
209 mtx_lock(&(kq)->kq_lock); \
211 #define KQ_FLUX_WAKEUP(kq) do { \
212 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \
213 (kq)->kq_state &= ~KQ_FLUXWAIT; \
217 #define KQ_UNLOCK_FLUX(kq) do { \
218 KQ_FLUX_WAKEUP(kq); \
219 mtx_unlock(&(kq)->kq_lock); \
221 #define KQ_UNLOCK(kq) do { \
222 mtx_unlock(&(kq)->kq_lock); \
224 #define KQ_OWNED(kq) do { \
225 mtx_assert(&(kq)->kq_lock, MA_OWNED); \
227 #define KQ_NOTOWNED(kq) do { \
228 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \
231 static struct knlist *
232 kn_list_lock(struct knote *kn)
238 knl->kl_lock(knl->kl_lockarg);
243 kn_list_unlock(struct knlist *knl)
249 do_free = knl->kl_autodestroy && knlist_empty(knl);
250 knl->kl_unlock(knl->kl_lockarg);
257 #define KNL_ASSERT_LOCK(knl, islocked) do { \
259 KNL_ASSERT_LOCKED(knl); \
261 KNL_ASSERT_UNLOCKED(knl); \
264 #define KNL_ASSERT_LOCKED(knl) do { \
265 knl->kl_assert_locked((knl)->kl_lockarg); \
267 #define KNL_ASSERT_UNLOCKED(knl) do { \
268 knl->kl_assert_unlocked((knl)->kl_lockarg); \
270 #else /* !INVARIANTS */
271 #define KNL_ASSERT_LOCKED(knl) do {} while(0)
272 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0)
273 #endif /* INVARIANTS */
276 #define KN_HASHSIZE 64 /* XXX should be tunable */
279 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
282 filt_nullattach(struct knote *kn)
288 struct filterops null_filtops = {
290 .f_attach = filt_nullattach,
293 /* XXX - make SYSINIT to add these, and move into respective modules. */
294 extern struct filterops sig_filtops;
295 extern struct filterops fs_filtops;
298 * Table for for all system-defined filters.
300 static struct mtx filterops_lock;
301 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops",
304 struct filterops *for_fop;
307 } sysfilt_ops[EVFILT_SYSCOUNT] = {
308 { &file_filtops, 1 }, /* EVFILT_READ */
309 { &file_filtops, 1 }, /* EVFILT_WRITE */
310 { &null_filtops }, /* EVFILT_AIO */
311 { &file_filtops, 1 }, /* EVFILT_VNODE */
312 { &proc_filtops, 1 }, /* EVFILT_PROC */
313 { &sig_filtops, 1 }, /* EVFILT_SIGNAL */
314 { &timer_filtops, 1 }, /* EVFILT_TIMER */
315 { &file_filtops, 1 }, /* EVFILT_PROCDESC */
316 { &fs_filtops, 1 }, /* EVFILT_FS */
317 { &null_filtops }, /* EVFILT_LIO */
318 { &user_filtops, 1 }, /* EVFILT_USER */
319 { &null_filtops }, /* EVFILT_SENDFILE */
323 * Simple redirection for all cdevsw style objects to call their fo_kqfilter
327 filt_fileattach(struct knote *kn)
330 return (fo_kqfilter(kn->kn_fp, kn));
335 kqueue_kqfilter(struct file *fp, struct knote *kn)
337 struct kqueue *kq = kn->kn_fp->f_data;
339 if (kn->kn_filter != EVFILT_READ)
342 kn->kn_status |= KN_KQUEUE;
343 kn->kn_fop = &kqread_filtops;
344 knlist_add(&kq->kq_sel.si_note, kn, 0);
350 filt_kqdetach(struct knote *kn)
352 struct kqueue *kq = kn->kn_fp->f_data;
354 knlist_remove(&kq->kq_sel.si_note, kn, 0);
359 filt_kqueue(struct knote *kn, long hint)
361 struct kqueue *kq = kn->kn_fp->f_data;
363 kn->kn_data = kq->kq_count;
364 return (kn->kn_data > 0);
367 /* XXX - move to kern_proc.c? */
369 filt_procattach(struct knote *kn)
373 bool exiting, immediate;
375 exiting = immediate = false;
376 p = pfind(kn->kn_id);
377 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) {
378 p = zpfind(kn->kn_id);
380 } else if (p != NULL && (p->p_flag & P_WEXIT)) {
386 if ((error = p_cansee(curthread, p))) {
391 kn->kn_ptr.p_proc = p;
392 kn->kn_flags |= EV_CLEAR; /* automatically set */
395 * Internal flag indicating registration done by kernel for the
396 * purposes of getting a NOTE_CHILD notification.
398 if (kn->kn_flags & EV_FLAG2) {
399 kn->kn_flags &= ~EV_FLAG2;
400 kn->kn_data = kn->kn_sdata; /* ppid */
401 kn->kn_fflags = NOTE_CHILD;
402 kn->kn_sfflags &= ~(NOTE_EXIT | NOTE_EXEC | NOTE_FORK);
403 immediate = true; /* Force immediate activation of child note. */
406 * Internal flag indicating registration done by kernel (for other than
409 if (kn->kn_flags & EV_FLAG1) {
410 kn->kn_flags &= ~EV_FLAG1;
413 knlist_add(p->p_klist, kn, 1);
416 * Immediately activate any child notes or, in the case of a zombie
417 * target process, exit notes. The latter is necessary to handle the
418 * case where the target process, e.g. a child, dies before the kevent
421 if (immediate || (exiting && filt_proc(kn, NOTE_EXIT)))
422 KNOTE_ACTIVATE(kn, 0);
430 * The knote may be attached to a different process, which may exit,
431 * leaving nothing for the knote to be attached to. So when the process
432 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
433 * it will be deleted when read out. However, as part of the knote deletion,
434 * this routine is called, so a check is needed to avoid actually performing
435 * a detach, because the original process does not exist any more.
437 /* XXX - move to kern_proc.c? */
439 filt_procdetach(struct knote *kn)
442 knlist_remove(kn->kn_knlist, kn, 0);
443 kn->kn_ptr.p_proc = NULL;
446 /* XXX - move to kern_proc.c? */
448 filt_proc(struct knote *kn, long hint)
453 p = kn->kn_ptr.p_proc;
454 /* Mask off extra data. */
455 event = (u_int)hint & NOTE_PCTRLMASK;
457 /* If the user is interested in this event, record it. */
458 if (kn->kn_sfflags & event)
459 kn->kn_fflags |= event;
461 /* Process is gone, so flag the event as finished. */
462 if (event == NOTE_EXIT) {
463 kn->kn_flags |= EV_EOF | EV_ONESHOT;
464 kn->kn_ptr.p_proc = NULL;
465 if (kn->kn_fflags & NOTE_EXIT)
466 kn->kn_data = KW_EXITCODE(p->p_xexit, p->p_xsig);
467 if (kn->kn_fflags == 0)
468 kn->kn_flags |= EV_DROP;
472 return (kn->kn_fflags != 0);
476 * Called when the process forked. It mostly does the same as the
477 * knote(), activating all knotes registered to be activated when the
478 * process forked. Additionally, for each knote attached to the
479 * parent, check whether user wants to track the new process. If so
480 * attach a new knote to it, and immediately report an event with the
484 knote_fork(struct knlist *list, int pid)
493 list->kl_lock(list->kl_lockarg);
495 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) {
498 if ((kn->kn_status & (KN_INFLUX | KN_SCAN)) == KN_INFLUX) {
504 * The same as knote(), activate the event.
506 if ((kn->kn_sfflags & NOTE_TRACK) == 0) {
507 kn->kn_status |= KN_HASKQLOCK;
508 if (kn->kn_fop->f_event(kn, NOTE_FORK))
509 KNOTE_ACTIVATE(kn, 1);
510 kn->kn_status &= ~KN_HASKQLOCK;
516 * The NOTE_TRACK case. In addition to the activation
517 * of the event, we need to register new events to
518 * track the child. Drop the locks in preparation for
519 * the call to kqueue_register().
521 kn->kn_status |= KN_INFLUX;
523 list->kl_unlock(list->kl_lockarg);
526 * Activate existing knote and register tracking knotes with
529 * First register a knote to get just the child notice. This
530 * must be a separate note from a potential NOTE_EXIT
531 * notification since both NOTE_CHILD and NOTE_EXIT are defined
532 * to use the data field (in conflicting ways).
535 kev.filter = kn->kn_filter;
536 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT |
538 kev.fflags = kn->kn_sfflags;
539 kev.data = kn->kn_id; /* parent */
540 kev.udata = kn->kn_kevent.udata;/* preserve udata */
541 error = kqueue_register(kq, &kev, NULL, 0);
543 kn->kn_fflags |= NOTE_TRACKERR;
546 * Then register another knote to track other potential events
547 * from the new process.
550 kev.filter = kn->kn_filter;
551 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
552 kev.fflags = kn->kn_sfflags;
553 kev.data = kn->kn_id; /* parent */
554 kev.udata = kn->kn_kevent.udata;/* preserve udata */
555 error = kqueue_register(kq, &kev, NULL, 0);
557 kn->kn_fflags |= NOTE_TRACKERR;
558 if (kn->kn_fop->f_event(kn, NOTE_FORK))
559 KNOTE_ACTIVATE(kn, 0);
561 kn->kn_status &= ~KN_INFLUX;
563 list->kl_lock(list->kl_lockarg);
565 list->kl_unlock(list->kl_lockarg);
569 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the
570 * interval timer support code.
573 #define NOTE_TIMER_PRECMASK (NOTE_SECONDS|NOTE_MSECONDS|NOTE_USECONDS| \
577 timer2sbintime(intptr_t data, int flags)
581 * Macros for converting to the fractional second portion of an
582 * sbintime_t using 64bit multiplication to improve precision.
584 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32)
585 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32)
586 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32)
587 switch (flags & NOTE_TIMER_PRECMASK) {
590 if (data > (SBT_MAX / SBT_1S))
593 return ((sbintime_t)data << 32);
594 case NOTE_MSECONDS: /* FALLTHROUGH */
597 int64_t secs = data / 1000;
599 if (secs > (SBT_MAX / SBT_1S))
602 return (secs << 32 | MS_TO_SBT(data % 1000));
604 return MS_TO_SBT(data);
606 if (data >= 1000000) {
607 int64_t secs = data / 1000000;
609 if (secs > (SBT_MAX / SBT_1S))
612 return (secs << 32 | US_TO_SBT(data % 1000000));
614 return US_TO_SBT(data);
616 if (data >= 1000000000) {
617 int64_t secs = data / 1000000000;
619 if (secs > (SBT_MAX / SBT_1S))
622 return (secs << 32 | US_TO_SBT(data % 1000000000));
624 return NS_TO_SBT(data);
632 filt_timerexpire(void *knx)
634 struct callout *calloutp;
639 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */
641 if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) {
642 calloutp = (struct callout *)kn->kn_hook;
643 *kn->kn_ptr.p_nexttime += timer2sbintime(kn->kn_sdata,
645 callout_reset_sbt_on(calloutp, *kn->kn_ptr.p_nexttime, 0,
646 filt_timerexpire, kn, PCPU_GET(cpuid), C_ABSOLUTE);
651 * data contains amount of time to sleep
654 filt_timerattach(struct knote *kn)
656 struct callout *calloutp;
658 unsigned int ncallouts;
660 if ((intptr_t)kn->kn_sdata < 0)
662 if ((intptr_t)kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0)
664 /* Only precision unit are supported in flags so far */
665 if (kn->kn_sfflags & ~NOTE_TIMER_PRECMASK)
668 to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags);
672 ncallouts = atomic_load_explicit(&kq_ncallouts, memory_order_relaxed);
674 if (ncallouts >= kq_calloutmax)
676 } while (!atomic_compare_exchange_weak_explicit(&kq_ncallouts,
677 &ncallouts, ncallouts + 1, memory_order_relaxed,
678 memory_order_relaxed));
680 kn->kn_flags |= EV_CLEAR; /* automatically set */
681 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */
682 kn->kn_ptr.p_nexttime = malloc(sizeof(sbintime_t), M_KQUEUE, M_WAITOK);
683 calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK);
684 callout_init(calloutp, 1);
685 kn->kn_hook = calloutp;
686 *kn->kn_ptr.p_nexttime = to + sbinuptime();
687 callout_reset_sbt_on(calloutp, *kn->kn_ptr.p_nexttime, 0,
688 filt_timerexpire, kn, PCPU_GET(cpuid), C_ABSOLUTE);
694 filt_timerdetach(struct knote *kn)
696 struct callout *calloutp;
699 calloutp = (struct callout *)kn->kn_hook;
700 callout_drain(calloutp);
701 free(calloutp, M_KQUEUE);
702 free(kn->kn_ptr.p_nexttime, M_KQUEUE);
703 old = atomic_fetch_sub_explicit(&kq_ncallouts, 1, memory_order_relaxed);
704 KASSERT(old > 0, ("Number of callouts cannot become negative"));
705 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */
709 filt_timer(struct knote *kn, long hint)
712 return (kn->kn_data != 0);
716 filt_userattach(struct knote *kn)
720 * EVFILT_USER knotes are not attached to anything in the kernel.
723 if (kn->kn_fflags & NOTE_TRIGGER)
731 filt_userdetach(__unused struct knote *kn)
735 * EVFILT_USER knotes are not attached to anything in the kernel.
740 filt_user(struct knote *kn, __unused long hint)
743 return (kn->kn_hookid);
747 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type)
753 if (kev->fflags & NOTE_TRIGGER)
756 ffctrl = kev->fflags & NOTE_FFCTRLMASK;
757 kev->fflags &= NOTE_FFLAGSMASK;
763 kn->kn_sfflags &= kev->fflags;
767 kn->kn_sfflags |= kev->fflags;
771 kn->kn_sfflags = kev->fflags;
775 /* XXX Return error? */
778 kn->kn_sdata = kev->data;
779 if (kev->flags & EV_CLEAR) {
787 *kev = kn->kn_kevent;
788 kev->fflags = kn->kn_sfflags;
789 kev->data = kn->kn_sdata;
790 if (kn->kn_flags & EV_CLEAR) {
798 panic("filt_usertouch() - invalid type (%ld)", type);
804 sys_kqueue(struct thread *td, struct kqueue_args *uap)
807 return (kern_kqueue(td, 0, NULL));
811 kqueue_init(struct kqueue *kq)
814 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK);
815 TAILQ_INIT(&kq->kq_head);
816 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock);
817 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq);
821 kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps)
823 struct filedesc *fdp;
829 fdp = td->td_proc->p_fd;
831 if (!chgkqcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_KQUEUES)))
834 error = falloc_caps(td, &fp, &fd, flags, fcaps);
836 chgkqcnt(cred->cr_ruidinfo, -1, 0);
840 /* An extra reference on `fp' has been held for us by falloc(). */
841 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO);
844 kq->kq_cred = crhold(cred);
847 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list);
848 FILEDESC_XUNLOCK(fdp);
850 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops);
853 td->td_retval[0] = fd;
857 #ifndef _SYS_SYSPROTO_H_
860 const struct kevent *changelist;
862 struct kevent *eventlist;
864 const struct timespec *timeout;
868 sys_kevent(struct thread *td, struct kevent_args *uap)
870 struct timespec ts, *tsp;
871 struct kevent_copyops k_ops = { uap,
878 struct uio *ktruioin = NULL;
879 struct uio *ktruioout = NULL;
882 if (uap->timeout != NULL) {
883 error = copyin(uap->timeout, &ts, sizeof(ts));
891 if (KTRPOINT(td, KTR_GENIO)) {
892 ktriov.iov_base = uap->changelist;
893 ktriov.iov_len = uap->nchanges * sizeof(struct kevent);
894 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1,
895 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ,
897 ktruioin = cloneuio(&ktruio);
898 ktriov.iov_base = uap->eventlist;
899 ktriov.iov_len = uap->nevents * sizeof(struct kevent);
900 ktruioout = cloneuio(&ktruio);
904 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents,
908 if (ktruioin != NULL) {
909 ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent);
910 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0);
911 ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent);
912 ktrgenio(uap->fd, UIO_READ, ktruioout, error);
920 * Copy 'count' items into the destination list pointed to by uap->eventlist.
923 kevent_copyout(void *arg, struct kevent *kevp, int count)
925 struct kevent_args *uap;
928 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count));
929 uap = (struct kevent_args *)arg;
931 error = copyout(kevp, uap->eventlist, count * sizeof *kevp);
933 uap->eventlist += count;
938 * Copy 'count' items from the list pointed to by uap->changelist.
941 kevent_copyin(void *arg, struct kevent *kevp, int count)
943 struct kevent_args *uap;
946 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count));
947 uap = (struct kevent_args *)arg;
949 error = copyin(uap->changelist, kevp, count * sizeof *kevp);
951 uap->changelist += count;
956 kern_kevent(struct thread *td, int fd, int nchanges, int nevents,
957 struct kevent_copyops *k_ops, const struct timespec *timeout)
963 cap_rights_init(&rights);
965 cap_rights_set(&rights, CAP_KQUEUE_CHANGE);
967 cap_rights_set(&rights, CAP_KQUEUE_EVENT);
968 error = fget(td, fd, &rights, &fp);
972 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout);
979 kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents,
980 struct kevent_copyops *k_ops, const struct timespec *timeout)
982 struct kevent keva[KQ_NEVENTS];
983 struct kevent *kevp, *changes;
984 int i, n, nerrors, error;
987 while (nchanges > 0) {
988 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges;
989 error = k_ops->k_copyin(k_ops->arg, keva, n);
993 for (i = 0; i < n; i++) {
997 kevp->flags &= ~EV_SYSFLAGS;
998 error = kqueue_register(kq, kevp, td, 1);
999 if (error || (kevp->flags & EV_RECEIPT)) {
1002 kevp->flags = EV_ERROR;
1004 (void)k_ops->k_copyout(k_ops->arg, kevp, 1);
1012 td->td_retval[0] = nerrors;
1016 return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td));
1020 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents,
1021 struct kevent_copyops *k_ops, const struct timespec *timeout)
1026 error = kqueue_acquire(fp, &kq);
1029 error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout);
1030 kqueue_release(kq, 0);
1035 * Performs a kevent() call on a temporarily created kqueue. This can be
1036 * used to perform one-shot polling, similar to poll() and select().
1039 kern_kevent_anonymous(struct thread *td, int nevents,
1040 struct kevent_copyops *k_ops)
1042 struct kqueue kq = {};
1047 error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL);
1048 kqueue_drain(&kq, td);
1049 kqueue_destroy(&kq);
1054 kqueue_add_filteropts(int filt, struct filterops *filtops)
1059 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) {
1061 "trying to add a filterop that is out of range: %d is beyond %d\n",
1062 ~filt, EVFILT_SYSCOUNT);
1065 mtx_lock(&filterops_lock);
1066 if (sysfilt_ops[~filt].for_fop != &null_filtops &&
1067 sysfilt_ops[~filt].for_fop != NULL)
1070 sysfilt_ops[~filt].for_fop = filtops;
1071 sysfilt_ops[~filt].for_refcnt = 0;
1073 mtx_unlock(&filterops_lock);
1079 kqueue_del_filteropts(int filt)
1084 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
1087 mtx_lock(&filterops_lock);
1088 if (sysfilt_ops[~filt].for_fop == &null_filtops ||
1089 sysfilt_ops[~filt].for_fop == NULL)
1091 else if (sysfilt_ops[~filt].for_refcnt != 0)
1094 sysfilt_ops[~filt].for_fop = &null_filtops;
1095 sysfilt_ops[~filt].for_refcnt = 0;
1097 mtx_unlock(&filterops_lock);
1102 static struct filterops *
1103 kqueue_fo_find(int filt)
1106 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
1109 if (sysfilt_ops[~filt].for_nolock)
1110 return sysfilt_ops[~filt].for_fop;
1112 mtx_lock(&filterops_lock);
1113 sysfilt_ops[~filt].for_refcnt++;
1114 if (sysfilt_ops[~filt].for_fop == NULL)
1115 sysfilt_ops[~filt].for_fop = &null_filtops;
1116 mtx_unlock(&filterops_lock);
1118 return sysfilt_ops[~filt].for_fop;
1122 kqueue_fo_release(int filt)
1125 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
1128 if (sysfilt_ops[~filt].for_nolock)
1131 mtx_lock(&filterops_lock);
1132 KASSERT(sysfilt_ops[~filt].for_refcnt > 0,
1133 ("filter object refcount not valid on release"));
1134 sysfilt_ops[~filt].for_refcnt--;
1135 mtx_unlock(&filterops_lock);
1139 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will
1140 * influence if memory allocation should wait. Make sure it is 0 if you
1144 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok)
1146 struct filterops *fops;
1148 struct knote *kn, *tkn;
1150 cap_rights_t rights;
1151 int error, filt, event;
1152 int haskqglobal, filedesc_unlock;
1154 if ((kev->flags & (EV_ENABLE | EV_DISABLE)) == (EV_ENABLE | EV_DISABLE))
1162 filedesc_unlock = 0;
1165 fops = kqueue_fo_find(filt);
1169 if (kev->flags & EV_ADD) {
1171 * Prevent waiting with locks. Non-sleepable
1172 * allocation failures are handled in the loop, only
1173 * if the spare knote appears to be actually required.
1175 tkn = knote_alloc(waitok);
1182 KASSERT(td != NULL, ("td is NULL"));
1183 error = fget(td, kev->ident,
1184 cap_rights_init(&rights, CAP_EVENT), &fp);
1188 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops,
1189 kev->ident, 0) != 0) {
1193 error = kqueue_expand(kq, fops, kev->ident, waitok);
1199 if (fp->f_type == DTYPE_KQUEUE) {
1201 * If we add some intelligence about what we are doing,
1202 * we should be able to support events on ourselves.
1203 * We need to know when we are doing this to prevent
1204 * getting both the knlist lock and the kq lock since
1205 * they are the same thing.
1207 if (fp->f_data == kq) {
1213 * Pre-lock the filedesc before the global
1214 * lock mutex, see the comment in
1217 FILEDESC_XLOCK(td->td_proc->p_fd);
1218 filedesc_unlock = 1;
1219 KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
1223 if (kev->ident < kq->kq_knlistsize) {
1224 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link)
1225 if (kev->filter == kn->kn_filter)
1229 if ((kev->flags & EV_ADD) == EV_ADD)
1230 kqueue_expand(kq, fops, kev->ident, waitok);
1235 * If possible, find an existing knote to use for this kevent.
1237 if (kev->filter == EVFILT_PROC &&
1238 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) {
1239 /* This is an internal creation of a process tracking
1240 * note. Don't attempt to coalesce this with an
1244 } else if (kq->kq_knhashmask != 0) {
1247 list = &kq->kq_knhash[
1248 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)];
1249 SLIST_FOREACH(kn, list, kn_link)
1250 if (kev->ident == kn->kn_id &&
1251 kev->filter == kn->kn_filter)
1256 /* knote is in the process of changing, wait for it to stabilize. */
1257 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1258 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1259 if (filedesc_unlock) {
1260 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1261 filedesc_unlock = 0;
1263 kq->kq_state |= KQ_FLUXWAIT;
1264 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0);
1273 * kn now contains the matching knote, or NULL if no match
1276 if (kev->flags & EV_ADD) {
1288 * apply reference counts to knote structure, and
1289 * do not release it at the end of this routine.
1294 kn->kn_sfflags = kev->fflags;
1295 kn->kn_sdata = kev->data;
1298 kn->kn_kevent = *kev;
1299 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE |
1300 EV_ENABLE | EV_DISABLE | EV_FORCEONESHOT);
1301 kn->kn_status = KN_INFLUX|KN_DETACHED;
1303 error = knote_attach(kn, kq);
1310 if ((error = kn->kn_fop->f_attach(kn)) != 0) {
1314 knl = kn_list_lock(kn);
1317 /* No matching knote and the EV_ADD flag is not set. */
1324 if (kev->flags & EV_DELETE) {
1325 kn->kn_status |= KN_INFLUX;
1327 if (!(kn->kn_status & KN_DETACHED))
1328 kn->kn_fop->f_detach(kn);
1333 if (kev->flags & EV_FORCEONESHOT) {
1334 kn->kn_flags |= EV_ONESHOT;
1335 KNOTE_ACTIVATE(kn, 1);
1339 * The user may change some filter values after the initial EV_ADD,
1340 * but doing so will not reset any filter which has already been
1343 kn->kn_status |= KN_INFLUX | KN_SCAN;
1345 knl = kn_list_lock(kn);
1346 kn->kn_kevent.udata = kev->udata;
1347 if (!fops->f_isfd && fops->f_touch != NULL) {
1348 fops->f_touch(kn, kev, EVENT_REGISTER);
1350 kn->kn_sfflags = kev->fflags;
1351 kn->kn_sdata = kev->data;
1355 * We can get here with kn->kn_knlist == NULL. This can happen when
1356 * the initial attach event decides that the event is "completed"
1357 * already. i.e. filt_procattach is called on a zombie process. It
1358 * will call filt_proc which will remove it from the list, and NULL
1362 if ((kev->flags & EV_ENABLE) != 0)
1363 kn->kn_status &= ~KN_DISABLED;
1364 else if ((kev->flags & EV_DISABLE) != 0)
1365 kn->kn_status |= KN_DISABLED;
1367 if ((kn->kn_status & KN_DISABLED) == 0)
1368 event = kn->kn_fop->f_event(kn, 0);
1374 kn->kn_status |= KN_ACTIVE;
1375 if ((kn->kn_status & (KN_ACTIVE | KN_DISABLED | KN_QUEUED)) ==
1378 kn->kn_status &= ~(KN_INFLUX | KN_SCAN);
1379 kn_list_unlock(knl);
1383 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1384 if (filedesc_unlock)
1385 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1390 kqueue_fo_release(filt);
1395 kqueue_acquire(struct file *fp, struct kqueue **kqp)
1403 if (fp->f_type != DTYPE_KQUEUE || kq == NULL)
1407 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) {
1418 kqueue_release(struct kqueue *kq, int locked)
1425 if (kq->kq_refcnt == 1)
1426 wakeup(&kq->kq_refcnt);
1432 kqueue_schedtask(struct kqueue *kq)
1436 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN),
1437 ("scheduling kqueue task while draining"));
1439 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) {
1440 taskqueue_enqueue(taskqueue_kqueue_ctx, &kq->kq_task);
1441 kq->kq_state |= KQ_TASKSCHED;
1446 * Expand the kq to make sure we have storage for fops/ident pair.
1448 * Return 0 on success (or no work necessary), return errno on failure.
1450 * Not calling hashinit w/ waitok (proper malloc flag) should be safe.
1451 * If kqueue_register is called from a non-fd context, there usually/should
1455 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
1458 struct klist *list, *tmp_knhash, *to_free;
1459 u_long tmp_knhashmask;
1462 int mflag = waitok ? M_WAITOK : M_NOWAIT;
1469 if (kq->kq_knlistsize <= fd) {
1470 size = kq->kq_knlistsize;
1473 list = malloc(size * sizeof(*list), M_KQUEUE, mflag);
1477 if (kq->kq_knlistsize > fd) {
1481 if (kq->kq_knlist != NULL) {
1482 bcopy(kq->kq_knlist, list,
1483 kq->kq_knlistsize * sizeof(*list));
1484 to_free = kq->kq_knlist;
1485 kq->kq_knlist = NULL;
1487 bzero((caddr_t)list +
1488 kq->kq_knlistsize * sizeof(*list),
1489 (size - kq->kq_knlistsize) * sizeof(*list));
1490 kq->kq_knlistsize = size;
1491 kq->kq_knlist = list;
1496 if (kq->kq_knhashmask == 0) {
1497 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
1499 if (tmp_knhash == NULL)
1502 if (kq->kq_knhashmask == 0) {
1503 kq->kq_knhash = tmp_knhash;
1504 kq->kq_knhashmask = tmp_knhashmask;
1506 to_free = tmp_knhash;
1511 free(to_free, M_KQUEUE);
1518 kqueue_task(void *arg, int pending)
1526 KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
1529 KNOTE_LOCKED(&kq->kq_sel.si_note, 0);
1531 kq->kq_state &= ~KQ_TASKSCHED;
1532 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) {
1533 wakeup(&kq->kq_state);
1536 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1540 * Scan, update kn_data (if not ONESHOT), and copyout triggered events.
1541 * We treat KN_MARKER knotes as if they are INFLUX.
1544 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops,
1545 const struct timespec *tsp, struct kevent *keva, struct thread *td)
1547 struct kevent *kevp;
1548 struct knote *kn, *marker;
1550 sbintime_t asbt, rsbt;
1551 int count, error, haskqglobal, influx, nkev, touch;
1563 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 ||
1564 tsp->tv_nsec >= 1000000000) {
1568 if (timespecisset(tsp)) {
1569 if (tsp->tv_sec <= INT32_MAX) {
1570 rsbt = tstosbt(*tsp);
1571 if (TIMESEL(&asbt, rsbt))
1572 asbt += tc_tick_sbt;
1573 if (asbt <= SBT_MAX - rsbt)
1577 rsbt >>= tc_precexp;
1584 marker = knote_alloc(1);
1585 marker->kn_status = KN_MARKER;
1590 if (kq->kq_count == 0) {
1592 error = EWOULDBLOCK;
1594 kq->kq_state |= KQ_SLEEP;
1595 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH,
1596 "kqread", asbt, rsbt, C_ABSOLUTE);
1600 /* don't restart after signals... */
1601 if (error == ERESTART)
1603 else if (error == EWOULDBLOCK)
1608 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe);
1612 kn = TAILQ_FIRST(&kq->kq_head);
1614 if ((kn->kn_status == KN_MARKER && kn != marker) ||
1615 (kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1620 kq->kq_state |= KQ_FLUXWAIT;
1621 error = msleep(kq, &kq->kq_lock, PSOCK,
1626 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
1627 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) {
1628 kn->kn_status &= ~KN_QUEUED;
1634 if (count == maxevents)
1638 KASSERT((kn->kn_status & KN_INFLUX) == 0,
1639 ("KN_INFLUX set when not suppose to be"));
1641 if ((kn->kn_flags & EV_DROP) == EV_DROP) {
1642 kn->kn_status &= ~KN_QUEUED;
1643 kn->kn_status |= KN_INFLUX;
1647 * We don't need to lock the list since we've marked
1650 if (!(kn->kn_status & KN_DETACHED))
1651 kn->kn_fop->f_detach(kn);
1655 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) {
1656 kn->kn_status &= ~KN_QUEUED;
1657 kn->kn_status |= KN_INFLUX;
1661 * We don't need to lock the list since we've marked
1664 *kevp = kn->kn_kevent;
1665 if (!(kn->kn_status & KN_DETACHED))
1666 kn->kn_fop->f_detach(kn);
1671 kn->kn_status |= KN_INFLUX | KN_SCAN;
1673 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE)
1674 KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
1675 knl = kn_list_lock(kn);
1676 if (kn->kn_fop->f_event(kn, 0) == 0) {
1678 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1680 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX |
1683 kn_list_unlock(knl);
1687 touch = (!kn->kn_fop->f_isfd &&
1688 kn->kn_fop->f_touch != NULL);
1690 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS);
1692 *kevp = kn->kn_kevent;
1694 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1695 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) {
1697 * Manually clear knotes who weren't
1700 if (touch == 0 && kn->kn_flags & EV_CLEAR) {
1704 if (kn->kn_flags & EV_DISPATCH)
1705 kn->kn_status |= KN_DISABLED;
1706 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
1709 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
1711 kn->kn_status &= ~(KN_INFLUX | KN_SCAN);
1712 kn_list_unlock(knl);
1716 /* we are returning a copy to the user */
1721 if (nkev == KQ_NEVENTS) {
1724 error = k_ops->k_copyout(k_ops->arg, keva, nkev);
1732 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe);
1740 error = k_ops->k_copyout(k_ops->arg, keva, nkev);
1741 td->td_retval[0] = maxevents - count;
1747 kqueue_ioctl(struct file *fp, u_long cmd, void *data,
1748 struct ucred *active_cred, struct thread *td)
1751 * Enabling sigio causes two major problems:
1752 * 1) infinite recursion:
1753 * Synopsys: kevent is being used to track signals and have FIOASYNC
1754 * set. On receipt of a signal this will cause a kqueue to recurse
1755 * into itself over and over. Sending the sigio causes the kqueue
1756 * to become ready, which in turn posts sigio again, forever.
1757 * Solution: this can be solved by setting a flag in the kqueue that
1758 * we have a SIGIO in progress.
1759 * 2) locking problems:
1760 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts
1761 * us above the proc and pgrp locks.
1762 * Solution: Post a signal using an async mechanism, being sure to
1763 * record a generation count in the delivery so that we do not deliver
1764 * a signal to the wrong process.
1766 * Note, these two mechanisms are somewhat mutually exclusive!
1775 kq->kq_state |= KQ_ASYNC;
1777 kq->kq_state &= ~KQ_ASYNC;
1782 return (fsetown(*(int *)data, &kq->kq_sigio));
1785 *(int *)data = fgetown(&kq->kq_sigio);
1795 kqueue_poll(struct file *fp, int events, struct ucred *active_cred,
1802 if ((error = kqueue_acquire(fp, &kq)))
1806 if (events & (POLLIN | POLLRDNORM)) {
1808 revents |= events & (POLLIN | POLLRDNORM);
1810 selrecord(td, &kq->kq_sel);
1811 if (SEL_WAITING(&kq->kq_sel))
1812 kq->kq_state |= KQ_SEL;
1815 kqueue_release(kq, 1);
1822 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
1826 bzero((void *)st, sizeof *st);
1828 * We no longer return kq_count because the unlocked value is useless.
1829 * If you spent all this time getting the count, why not spend your
1830 * syscall better by calling kevent?
1832 * XXX - This is needed for libc_r.
1834 st->st_mode = S_IFIFO;
1839 kqueue_drain(struct kqueue *kq, struct thread *td)
1846 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING,
1847 ("kqueue already closing"));
1848 kq->kq_state |= KQ_CLOSING;
1849 if (kq->kq_refcnt > 1)
1850 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0);
1852 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!"));
1854 KASSERT(knlist_empty(&kq->kq_sel.si_note),
1855 ("kqueue's knlist not empty"));
1857 for (i = 0; i < kq->kq_knlistsize; i++) {
1858 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) {
1859 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1860 kq->kq_state |= KQ_FLUXWAIT;
1861 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0);
1864 kn->kn_status |= KN_INFLUX;
1866 if (!(kn->kn_status & KN_DETACHED))
1867 kn->kn_fop->f_detach(kn);
1872 if (kq->kq_knhashmask != 0) {
1873 for (i = 0; i <= kq->kq_knhashmask; i++) {
1874 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) {
1875 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1876 kq->kq_state |= KQ_FLUXWAIT;
1877 msleep(kq, &kq->kq_lock, PSOCK,
1881 kn->kn_status |= KN_INFLUX;
1883 if (!(kn->kn_status & KN_DETACHED))
1884 kn->kn_fop->f_detach(kn);
1891 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) {
1892 kq->kq_state |= KQ_TASKDRAIN;
1893 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0);
1896 if ((kq->kq_state & KQ_SEL) == KQ_SEL) {
1897 selwakeuppri(&kq->kq_sel, PSOCK);
1898 if (!SEL_WAITING(&kq->kq_sel))
1899 kq->kq_state &= ~KQ_SEL;
1906 kqueue_destroy(struct kqueue *kq)
1909 KASSERT(kq->kq_fdp == NULL,
1910 ("kqueue still attached to a file descriptor"));
1911 seldrain(&kq->kq_sel);
1912 knlist_destroy(&kq->kq_sel.si_note);
1913 mtx_destroy(&kq->kq_lock);
1915 if (kq->kq_knhash != NULL)
1916 free(kq->kq_knhash, M_KQUEUE);
1917 if (kq->kq_knlist != NULL)
1918 free(kq->kq_knlist, M_KQUEUE);
1920 funsetown(&kq->kq_sigio);
1925 kqueue_close(struct file *fp, struct thread *td)
1927 struct kqueue *kq = fp->f_data;
1928 struct filedesc *fdp;
1930 int filedesc_unlock;
1932 if ((error = kqueue_acquire(fp, &kq)))
1934 kqueue_drain(kq, td);
1937 * We could be called due to the knote_drop() doing fdrop(),
1938 * called from kqueue_register(). In this case the global
1939 * lock is owned, and filedesc sx is locked before, to not
1940 * take the sleepable lock after non-sleepable.
1944 if (!sx_xlocked(FILEDESC_LOCK(fdp))) {
1945 FILEDESC_XLOCK(fdp);
1946 filedesc_unlock = 1;
1948 filedesc_unlock = 0;
1949 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list);
1950 if (filedesc_unlock)
1951 FILEDESC_XUNLOCK(fdp);
1954 chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0);
1955 crfree(kq->kq_cred);
1963 kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
1966 kif->kf_type = KF_TYPE_KQUEUE;
1971 kqueue_wakeup(struct kqueue *kq)
1975 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) {
1976 kq->kq_state &= ~KQ_SLEEP;
1979 if ((kq->kq_state & KQ_SEL) == KQ_SEL) {
1980 selwakeuppri(&kq->kq_sel, PSOCK);
1981 if (!SEL_WAITING(&kq->kq_sel))
1982 kq->kq_state &= ~KQ_SEL;
1984 if (!knlist_empty(&kq->kq_sel.si_note))
1985 kqueue_schedtask(kq);
1986 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) {
1987 pgsigio(&kq->kq_sigio, SIGIO, 0);
1992 * Walk down a list of knotes, activating them if their event has triggered.
1994 * There is a possibility to optimize in the case of one kq watching another.
1995 * Instead of scheduling a task to wake it up, you could pass enough state
1996 * down the chain to make up the parent kqueue. Make this code functional
2000 knote(struct knlist *list, long hint, int lockflags)
2003 struct knote *kn, *tkn;
2009 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED);
2011 if ((lockflags & KNF_LISTLOCKED) == 0)
2012 list->kl_lock(list->kl_lockarg);
2015 * If we unlock the list lock (and set KN_INFLUX), we can
2016 * eliminate the kqueue scheduling, but this will introduce
2017 * four lock/unlock's for each knote to test. Also, marker
2018 * would be needed to keep iteration position, since filters
2019 * or other threads could remove events.
2021 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) {
2024 if ((kn->kn_status & (KN_INFLUX | KN_SCAN)) == KN_INFLUX) {
2026 * Do not process the influx notes, except for
2027 * the influx coming from the kq unlock in the
2028 * kqueue_scan(). In the later case, we do
2029 * not interfere with the scan, since the code
2030 * fragment in kqueue_scan() locks the knlist,
2031 * and cannot proceed until we finished.
2034 } else if ((lockflags & KNF_NOKQLOCK) != 0) {
2035 kn->kn_status |= KN_INFLUX;
2037 error = kn->kn_fop->f_event(kn, hint);
2039 kn->kn_status &= ~KN_INFLUX;
2041 KNOTE_ACTIVATE(kn, 1);
2044 kn->kn_status |= KN_HASKQLOCK;
2045 if (kn->kn_fop->f_event(kn, hint))
2046 KNOTE_ACTIVATE(kn, 1);
2047 kn->kn_status &= ~KN_HASKQLOCK;
2051 if ((lockflags & KNF_LISTLOCKED) == 0)
2052 list->kl_unlock(list->kl_lockarg);
2056 * add a knote to a knlist
2059 knlist_add(struct knlist *knl, struct knote *kn, int islocked)
2061 KNL_ASSERT_LOCK(knl, islocked);
2062 KQ_NOTOWNED(kn->kn_kq);
2063 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) ==
2064 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED"));
2066 knl->kl_lock(knl->kl_lockarg);
2067 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext);
2069 knl->kl_unlock(knl->kl_lockarg);
2071 kn->kn_knlist = knl;
2072 kn->kn_status &= ~KN_DETACHED;
2073 KQ_UNLOCK(kn->kn_kq);
2077 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked,
2080 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked"));
2081 KNL_ASSERT_LOCK(knl, knlislocked);
2082 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED);
2084 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX,
2085 ("knlist_remove called w/o knote being KN_INFLUX or already removed"));
2087 knl->kl_lock(knl->kl_lockarg);
2088 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext);
2089 kn->kn_knlist = NULL;
2091 kn_list_unlock(knl);
2094 kn->kn_status |= KN_DETACHED;
2096 KQ_UNLOCK(kn->kn_kq);
2100 * remove knote from the specified knlist
2103 knlist_remove(struct knlist *knl, struct knote *kn, int islocked)
2106 knlist_remove_kq(knl, kn, islocked, 0);
2110 knlist_empty(struct knlist *knl)
2113 KNL_ASSERT_LOCKED(knl);
2114 return SLIST_EMPTY(&knl->kl_list);
2117 static struct mtx knlist_lock;
2118 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects",
2120 static void knlist_mtx_lock(void *arg);
2121 static void knlist_mtx_unlock(void *arg);
2124 knlist_mtx_lock(void *arg)
2127 mtx_lock((struct mtx *)arg);
2131 knlist_mtx_unlock(void *arg)
2134 mtx_unlock((struct mtx *)arg);
2138 knlist_mtx_assert_locked(void *arg)
2141 mtx_assert((struct mtx *)arg, MA_OWNED);
2145 knlist_mtx_assert_unlocked(void *arg)
2148 mtx_assert((struct mtx *)arg, MA_NOTOWNED);
2152 knlist_rw_rlock(void *arg)
2155 rw_rlock((struct rwlock *)arg);
2159 knlist_rw_runlock(void *arg)
2162 rw_runlock((struct rwlock *)arg);
2166 knlist_rw_assert_locked(void *arg)
2169 rw_assert((struct rwlock *)arg, RA_LOCKED);
2173 knlist_rw_assert_unlocked(void *arg)
2176 rw_assert((struct rwlock *)arg, RA_UNLOCKED);
2180 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
2181 void (*kl_unlock)(void *),
2182 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *))
2186 knl->kl_lockarg = &knlist_lock;
2188 knl->kl_lockarg = lock;
2190 if (kl_lock == NULL)
2191 knl->kl_lock = knlist_mtx_lock;
2193 knl->kl_lock = kl_lock;
2194 if (kl_unlock == NULL)
2195 knl->kl_unlock = knlist_mtx_unlock;
2197 knl->kl_unlock = kl_unlock;
2198 if (kl_assert_locked == NULL)
2199 knl->kl_assert_locked = knlist_mtx_assert_locked;
2201 knl->kl_assert_locked = kl_assert_locked;
2202 if (kl_assert_unlocked == NULL)
2203 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked;
2205 knl->kl_assert_unlocked = kl_assert_unlocked;
2207 knl->kl_autodestroy = 0;
2208 SLIST_INIT(&knl->kl_list);
2212 knlist_init_mtx(struct knlist *knl, struct mtx *lock)
2215 knlist_init(knl, lock, NULL, NULL, NULL, NULL);
2219 knlist_alloc(struct mtx *lock)
2223 knl = malloc(sizeof(struct knlist), M_KQUEUE, M_WAITOK);
2224 knlist_init_mtx(knl, lock);
2229 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock)
2232 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock,
2233 knlist_rw_assert_locked, knlist_rw_assert_unlocked);
2237 knlist_destroy(struct knlist *knl)
2242 * if we run across this error, we need to find the offending
2243 * driver and have it call knlist_clear or knlist_delete.
2245 if (!SLIST_EMPTY(&knl->kl_list))
2246 printf("WARNING: destroying knlist w/ knotes on it!\n");
2249 knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL;
2250 SLIST_INIT(&knl->kl_list);
2254 knlist_detach(struct knlist *knl)
2257 KNL_ASSERT_LOCKED(knl);
2258 knl->kl_autodestroy = 1;
2259 if (knlist_empty(knl)) {
2260 knlist_destroy(knl);
2261 free(knl, M_KQUEUE);
2266 * Even if we are locked, we may need to drop the lock to allow any influx
2267 * knotes time to "settle".
2270 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn)
2272 struct knote *kn, *kn2;
2275 KASSERT(!knl->kl_autodestroy, ("cleardel for autodestroy %p", knl));
2277 KNL_ASSERT_LOCKED(knl);
2279 KNL_ASSERT_UNLOCKED(knl);
2280 again: /* need to reacquire lock since we have dropped it */
2281 knl->kl_lock(knl->kl_lockarg);
2284 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) {
2287 if ((kn->kn_status & KN_INFLUX)) {
2291 knlist_remove_kq(knl, kn, 1, 1);
2293 kn->kn_status |= KN_INFLUX | KN_DETACHED;
2297 /* Make sure cleared knotes disappear soon */
2298 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
2304 if (!SLIST_EMPTY(&knl->kl_list)) {
2305 /* there are still KN_INFLUX remaining */
2306 kn = SLIST_FIRST(&knl->kl_list);
2309 KASSERT(kn->kn_status & KN_INFLUX,
2310 ("knote removed w/o list lock"));
2311 knl->kl_unlock(knl->kl_lockarg);
2312 kq->kq_state |= KQ_FLUXWAIT;
2313 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0);
2319 KNL_ASSERT_LOCKED(knl);
2321 knl->kl_unlock(knl->kl_lockarg);
2322 KNL_ASSERT_UNLOCKED(knl);
2327 * Remove all knotes referencing a specified fd must be called with FILEDESC
2328 * lock. This prevents a race where a new fd comes along and occupies the
2329 * entry and we attach a knote to the fd.
2332 knote_fdclose(struct thread *td, int fd)
2334 struct filedesc *fdp = td->td_proc->p_fd;
2339 FILEDESC_XLOCK_ASSERT(fdp);
2342 * We shouldn't have to worry about new kevents appearing on fd
2343 * since filedesc is locked.
2345 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) {
2350 while (kq->kq_knlistsize > fd &&
2351 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) {
2352 if (kn->kn_status & KN_INFLUX) {
2353 /* someone else might be waiting on our knote */
2356 kq->kq_state |= KQ_FLUXWAIT;
2357 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0);
2360 kn->kn_status |= KN_INFLUX;
2362 if (!(kn->kn_status & KN_DETACHED))
2363 kn->kn_fop->f_detach(kn);
2373 knote_attach(struct knote *kn, struct kqueue *kq)
2377 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX"));
2380 if (kn->kn_fop->f_isfd) {
2381 if (kn->kn_id >= kq->kq_knlistsize)
2383 list = &kq->kq_knlist[kn->kn_id];
2385 if (kq->kq_knhash == NULL)
2387 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
2390 SLIST_INSERT_HEAD(list, kn, kn_link);
2396 * knote must already have been detached using the f_detach method.
2397 * no lock need to be held, it is assumed that the KN_INFLUX flag is set
2398 * to prevent other removal.
2401 knote_drop(struct knote *kn, struct thread *td)
2409 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX,
2410 ("knote_drop called without KN_INFLUX set in kn_status"));
2413 if (kn->kn_fop->f_isfd)
2414 list = &kq->kq_knlist[kn->kn_id];
2416 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
2418 if (!SLIST_EMPTY(list))
2419 SLIST_REMOVE(list, kn, knote, kn_link);
2420 if (kn->kn_status & KN_QUEUED)
2424 if (kn->kn_fop->f_isfd) {
2425 fdrop(kn->kn_fp, td);
2428 kqueue_fo_release(kn->kn_kevent.filter);
2434 knote_enqueue(struct knote *kn)
2436 struct kqueue *kq = kn->kn_kq;
2438 KQ_OWNED(kn->kn_kq);
2439 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
2441 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
2442 kn->kn_status |= KN_QUEUED;
2448 knote_dequeue(struct knote *kn)
2450 struct kqueue *kq = kn->kn_kq;
2452 KQ_OWNED(kn->kn_kq);
2453 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
2455 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
2456 kn->kn_status &= ~KN_QUEUED;
2464 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL,
2465 NULL, NULL, UMA_ALIGN_PTR, 0);
2467 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL);
2469 static struct knote *
2470 knote_alloc(int waitok)
2473 return (uma_zalloc(knote_zone, (waitok ? M_WAITOK : M_NOWAIT) |
2478 knote_free(struct knote *kn)
2481 uma_zfree(knote_zone, kn);
2485 * Register the kev w/ the kq specified by fd.
2488 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok)
2492 cap_rights_t rights;
2495 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp);
2498 if ((error = kqueue_acquire(fp, &kq)) != 0)
2501 error = kqueue_register(kq, kev, td, waitok);
2503 kqueue_release(kq, 0);