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"
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/capsicum.h>
37 #include <sys/kernel.h>
39 #include <sys/mutex.h>
40 #include <sys/rwlock.h>
42 #include <sys/malloc.h>
43 #include <sys/unistd.h>
45 #include <sys/filedesc.h>
46 #include <sys/filio.h>
47 #include <sys/fcntl.h>
48 #include <sys/kthread.h>
49 #include <sys/selinfo.h>
50 #include <sys/queue.h>
51 #include <sys/event.h>
52 #include <sys/eventvar.h>
54 #include <sys/protosw.h>
55 #include <sys/sigio.h>
56 #include <sys/signalvar.h>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
60 #include <sys/sysctl.h>
61 #include <sys/sysproto.h>
62 #include <sys/syscallsubr.h>
63 #include <sys/taskqueue.h>
66 #include <sys/ktrace.h>
68 #include <machine/atomic.h>
72 static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
75 * This lock is used if multiple kq locks are required. This possibly
76 * should be made into a per proc lock.
78 static struct mtx kq_global;
79 MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF);
80 #define KQ_GLOBAL_LOCK(lck, haslck) do { \
85 #define KQ_GLOBAL_UNLOCK(lck, haslck) do { \
91 TASKQUEUE_DEFINE_THREAD(kqueue);
93 static int kevent_copyout(void *arg, struct kevent *kevp, int count);
94 static int kevent_copyin(void *arg, struct kevent *kevp, int count);
95 static int kqueue_register(struct kqueue *kq, struct kevent *kev,
96 struct thread *td, int waitok);
97 static int kqueue_acquire(struct file *fp, struct kqueue **kqp);
98 static void kqueue_release(struct kqueue *kq, int locked);
99 static int kqueue_expand(struct kqueue *kq, struct filterops *fops,
100 uintptr_t ident, int waitok);
101 static void kqueue_task(void *arg, int pending);
102 static int kqueue_scan(struct kqueue *kq, int maxevents,
103 struct kevent_copyops *k_ops,
104 const struct timespec *timeout,
105 struct kevent *keva, struct thread *td);
106 static void kqueue_wakeup(struct kqueue *kq);
107 static struct filterops *kqueue_fo_find(int filt);
108 static void kqueue_fo_release(int filt);
110 static fo_rdwr_t kqueue_read;
111 static fo_rdwr_t kqueue_write;
112 static fo_truncate_t kqueue_truncate;
113 static fo_ioctl_t kqueue_ioctl;
114 static fo_poll_t kqueue_poll;
115 static fo_kqfilter_t kqueue_kqfilter;
116 static fo_stat_t kqueue_stat;
117 static fo_close_t kqueue_close;
119 static struct fileops kqueueops = {
120 .fo_read = kqueue_read,
121 .fo_write = kqueue_write,
122 .fo_truncate = kqueue_truncate,
123 .fo_ioctl = kqueue_ioctl,
124 .fo_poll = kqueue_poll,
125 .fo_kqfilter = kqueue_kqfilter,
126 .fo_stat = kqueue_stat,
127 .fo_close = kqueue_close,
128 .fo_chmod = invfo_chmod,
129 .fo_chown = invfo_chown,
130 .fo_sendfile = invfo_sendfile,
133 static int knote_attach(struct knote *kn, struct kqueue *kq);
134 static void knote_drop(struct knote *kn, struct thread *td);
135 static void knote_enqueue(struct knote *kn);
136 static void knote_dequeue(struct knote *kn);
137 static void knote_init(void);
138 static struct knote *knote_alloc(int waitok);
139 static void knote_free(struct knote *kn);
141 static void filt_kqdetach(struct knote *kn);
142 static int filt_kqueue(struct knote *kn, long hint);
143 static int filt_procattach(struct knote *kn);
144 static void filt_procdetach(struct knote *kn);
145 static int filt_proc(struct knote *kn, long hint);
146 static int filt_fileattach(struct knote *kn);
147 static void filt_timerexpire(void *knx);
148 static int filt_timerattach(struct knote *kn);
149 static void filt_timerdetach(struct knote *kn);
150 static int filt_timer(struct knote *kn, long hint);
151 static int filt_userattach(struct knote *kn);
152 static void filt_userdetach(struct knote *kn);
153 static int filt_user(struct knote *kn, long hint);
154 static void filt_usertouch(struct knote *kn, struct kevent *kev,
157 static struct filterops file_filtops = {
159 .f_attach = filt_fileattach,
161 static struct filterops kqread_filtops = {
163 .f_detach = filt_kqdetach,
164 .f_event = filt_kqueue,
166 /* XXX - move to kern_proc.c? */
167 static struct filterops proc_filtops = {
169 .f_attach = filt_procattach,
170 .f_detach = filt_procdetach,
171 .f_event = filt_proc,
173 static struct filterops timer_filtops = {
175 .f_attach = filt_timerattach,
176 .f_detach = filt_timerdetach,
177 .f_event = filt_timer,
179 static struct filterops user_filtops = {
180 .f_attach = filt_userattach,
181 .f_detach = filt_userdetach,
182 .f_event = filt_user,
183 .f_touch = filt_usertouch,
186 static uma_zone_t knote_zone;
187 static unsigned int kq_ncallouts = 0;
188 static unsigned int kq_calloutmax = 4 * 1024;
189 SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
190 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
192 /* XXX - ensure not KN_INFLUX?? */
193 #define KNOTE_ACTIVATE(kn, islock) do { \
195 mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \
197 KQ_LOCK((kn)->kn_kq); \
198 (kn)->kn_status |= KN_ACTIVE; \
199 if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
200 knote_enqueue((kn)); \
202 KQ_UNLOCK((kn)->kn_kq); \
204 #define KQ_LOCK(kq) do { \
205 mtx_lock(&(kq)->kq_lock); \
207 #define KQ_FLUX_WAKEUP(kq) do { \
208 if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \
209 (kq)->kq_state &= ~KQ_FLUXWAIT; \
213 #define KQ_UNLOCK_FLUX(kq) do { \
214 KQ_FLUX_WAKEUP(kq); \
215 mtx_unlock(&(kq)->kq_lock); \
217 #define KQ_UNLOCK(kq) do { \
218 mtx_unlock(&(kq)->kq_lock); \
220 #define KQ_OWNED(kq) do { \
221 mtx_assert(&(kq)->kq_lock, MA_OWNED); \
223 #define KQ_NOTOWNED(kq) do { \
224 mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \
226 #define KN_LIST_LOCK(kn) do { \
227 if (kn->kn_knlist != NULL) \
228 kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \
230 #define KN_LIST_UNLOCK(kn) do { \
231 if (kn->kn_knlist != NULL) \
232 kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \
234 #define KNL_ASSERT_LOCK(knl, islocked) do { \
236 KNL_ASSERT_LOCKED(knl); \
238 KNL_ASSERT_UNLOCKED(knl); \
241 #define KNL_ASSERT_LOCKED(knl) do { \
242 knl->kl_assert_locked((knl)->kl_lockarg); \
244 #define KNL_ASSERT_UNLOCKED(knl) do { \
245 knl->kl_assert_unlocked((knl)->kl_lockarg); \
247 #else /* !INVARIANTS */
248 #define KNL_ASSERT_LOCKED(knl) do {} while(0)
249 #define KNL_ASSERT_UNLOCKED(knl) do {} while (0)
250 #endif /* INVARIANTS */
252 #define KN_HASHSIZE 64 /* XXX should be tunable */
253 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
256 filt_nullattach(struct knote *kn)
262 struct filterops null_filtops = {
264 .f_attach = filt_nullattach,
267 /* XXX - make SYSINIT to add these, and move into respective modules. */
268 extern struct filterops sig_filtops;
269 extern struct filterops fs_filtops;
272 * Table for for all system-defined filters.
274 static struct mtx filterops_lock;
275 MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops",
278 struct filterops *for_fop;
280 } sysfilt_ops[EVFILT_SYSCOUNT] = {
281 { &file_filtops }, /* EVFILT_READ */
282 { &file_filtops }, /* EVFILT_WRITE */
283 { &null_filtops }, /* EVFILT_AIO */
284 { &file_filtops }, /* EVFILT_VNODE */
285 { &proc_filtops }, /* EVFILT_PROC */
286 { &sig_filtops }, /* EVFILT_SIGNAL */
287 { &timer_filtops }, /* EVFILT_TIMER */
288 { &null_filtops }, /* former EVFILT_NETDEV */
289 { &fs_filtops }, /* EVFILT_FS */
290 { &null_filtops }, /* EVFILT_LIO */
291 { &user_filtops }, /* EVFILT_USER */
295 * Simple redirection for all cdevsw style objects to call their fo_kqfilter
299 filt_fileattach(struct knote *kn)
302 return (fo_kqfilter(kn->kn_fp, kn));
307 kqueue_kqfilter(struct file *fp, struct knote *kn)
309 struct kqueue *kq = kn->kn_fp->f_data;
311 if (kn->kn_filter != EVFILT_READ)
314 kn->kn_status |= KN_KQUEUE;
315 kn->kn_fop = &kqread_filtops;
316 knlist_add(&kq->kq_sel.si_note, kn, 0);
322 filt_kqdetach(struct knote *kn)
324 struct kqueue *kq = kn->kn_fp->f_data;
326 knlist_remove(&kq->kq_sel.si_note, kn, 0);
331 filt_kqueue(struct knote *kn, long hint)
333 struct kqueue *kq = kn->kn_fp->f_data;
335 kn->kn_data = kq->kq_count;
336 return (kn->kn_data > 0);
339 /* XXX - move to kern_proc.c? */
341 filt_procattach(struct knote *kn)
348 p = pfind(kn->kn_id);
349 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) {
350 p = zpfind(kn->kn_id);
352 } else if (p != NULL && (p->p_flag & P_WEXIT)) {
358 if ((error = p_cansee(curthread, p))) {
363 kn->kn_ptr.p_proc = p;
364 kn->kn_flags |= EV_CLEAR; /* automatically set */
367 * Internal flag indicating registration done by kernel for the
368 * purposes of getting a NOTE_CHILD notification.
370 if (kn->kn_flags & EV_FLAG2) {
371 kn->kn_flags &= ~EV_FLAG2;
372 kn->kn_data = kn->kn_sdata; /* ppid */
373 kn->kn_fflags = NOTE_CHILD;
374 kn->kn_sfflags &= ~NOTE_EXIT;
375 immediate = 1; /* Force immediate activation of child note. */
378 * Internal flag indicating registration done by kernel (for other than
381 if (kn->kn_flags & EV_FLAG1) {
382 kn->kn_flags &= ~EV_FLAG1;
386 knlist_add(&p->p_klist, kn, 1);
389 * Immediately activate any child notes or, in the case of a zombie
390 * target process, exit notes. The latter is necessary to handle the
391 * case where the target process, e.g. a child, dies before the kevent
394 if (immediate && filt_proc(kn, NOTE_EXIT))
395 KNOTE_ACTIVATE(kn, 0);
403 * The knote may be attached to a different process, which may exit,
404 * leaving nothing for the knote to be attached to. So when the process
405 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
406 * it will be deleted when read out. However, as part of the knote deletion,
407 * this routine is called, so a check is needed to avoid actually performing
408 * a detach, because the original process does not exist any more.
410 /* XXX - move to kern_proc.c? */
412 filt_procdetach(struct knote *kn)
416 p = kn->kn_ptr.p_proc;
417 knlist_remove(&p->p_klist, kn, 0);
418 kn->kn_ptr.p_proc = NULL;
421 /* XXX - move to kern_proc.c? */
423 filt_proc(struct knote *kn, long hint)
425 struct proc *p = kn->kn_ptr.p_proc;
429 * mask off extra data
431 event = (u_int)hint & NOTE_PCTRLMASK;
434 * if the user is interested in this event, record it.
436 if (kn->kn_sfflags & event)
437 kn->kn_fflags |= event;
440 * process is gone, so flag the event as finished.
442 if (event == NOTE_EXIT) {
443 if (!(kn->kn_status & KN_DETACHED))
444 knlist_remove_inevent(&p->p_klist, kn);
445 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
446 kn->kn_ptr.p_proc = NULL;
447 if (kn->kn_fflags & NOTE_EXIT)
448 kn->kn_data = p->p_xstat;
449 if (kn->kn_fflags == 0)
450 kn->kn_flags |= EV_DROP;
454 return (kn->kn_fflags != 0);
458 * Called when the process forked. It mostly does the same as the
459 * knote(), activating all knotes registered to be activated when the
460 * process forked. Additionally, for each knote attached to the
461 * parent, check whether user wants to track the new process. If so
462 * attach a new knote to it, and immediately report an event with the
466 knote_fork(struct knlist *list, int pid)
475 list->kl_lock(list->kl_lockarg);
477 SLIST_FOREACH(kn, &list->kl_list, kn_selnext) {
478 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX)
482 if ((kn->kn_status & (KN_INFLUX | KN_SCAN)) == KN_INFLUX) {
488 * The same as knote(), activate the event.
490 if ((kn->kn_sfflags & NOTE_TRACK) == 0) {
491 kn->kn_status |= KN_HASKQLOCK;
492 if (kn->kn_fop->f_event(kn, NOTE_FORK))
493 KNOTE_ACTIVATE(kn, 1);
494 kn->kn_status &= ~KN_HASKQLOCK;
500 * The NOTE_TRACK case. In addition to the activation
501 * of the event, we need to register new events to
502 * track the child. Drop the locks in preparation for
503 * the call to kqueue_register().
505 kn->kn_status |= KN_INFLUX;
507 list->kl_unlock(list->kl_lockarg);
510 * Activate existing knote and register tracking knotes with
513 * First register a knote to get just the child notice. This
514 * must be a separate note from a potential NOTE_EXIT
515 * notification since both NOTE_CHILD and NOTE_EXIT are defined
516 * to use the data field (in conflicting ways).
519 kev.filter = kn->kn_filter;
520 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_ONESHOT | EV_FLAG2;
521 kev.fflags = kn->kn_sfflags;
522 kev.data = kn->kn_id; /* parent */
523 kev.udata = kn->kn_kevent.udata;/* preserve udata */
524 error = kqueue_register(kq, &kev, NULL, 0);
526 kn->kn_fflags |= NOTE_TRACKERR;
529 * Then register another knote to track other potential events
530 * from the new process.
533 kev.filter = kn->kn_filter;
534 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
535 kev.fflags = kn->kn_sfflags;
536 kev.data = kn->kn_id; /* parent */
537 kev.udata = kn->kn_kevent.udata;/* preserve udata */
538 error = kqueue_register(kq, &kev, NULL, 0);
540 kn->kn_fflags |= NOTE_TRACKERR;
541 if (kn->kn_fop->f_event(kn, NOTE_FORK))
542 KNOTE_ACTIVATE(kn, 0);
544 kn->kn_status &= ~KN_INFLUX;
546 list->kl_lock(list->kl_lockarg);
548 list->kl_unlock(list->kl_lockarg);
552 * XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the
553 * interval timer support code.
556 #define NOTE_TIMER_PRECMASK (NOTE_SECONDS|NOTE_MSECONDS|NOTE_USECONDS| \
560 timer2sbintime(intptr_t data, int flags)
564 * Macros for converting to the fractional second portion of an
565 * sbintime_t using 64bit multiplication to improve precision.
567 #define NS_TO_SBT(ns) (((ns) * (((uint64_t)1 << 63) / 500000000)) >> 32)
568 #define US_TO_SBT(us) (((us) * (((uint64_t)1 << 63) / 500000)) >> 32)
569 #define MS_TO_SBT(ms) (((ms) * (((uint64_t)1 << 63) / 500)) >> 32)
570 switch (flags & NOTE_TIMER_PRECMASK) {
573 if (data > (SBT_MAX / SBT_1S))
576 return ((sbintime_t)data << 32);
577 case NOTE_MSECONDS: /* FALLTHROUGH */
580 int64_t secs = data / 1000;
582 if (secs > (SBT_MAX / SBT_1S))
585 return (secs << 32 | MS_TO_SBT(data % 1000));
587 return MS_TO_SBT(data);
589 if (data >= 1000000) {
590 int64_t secs = data / 1000000;
592 if (secs > (SBT_MAX / SBT_1S))
595 return (secs << 32 | US_TO_SBT(data % 1000000));
597 return US_TO_SBT(data);
599 if (data >= 1000000000) {
600 int64_t secs = data / 1000000000;
602 if (secs > (SBT_MAX / SBT_1S))
605 return (secs << 32 | US_TO_SBT(data % 1000000000));
607 return (NS_TO_SBT(data));
614 struct kq_timer_cb_data {
616 sbintime_t next; /* next timer event fires at */
617 sbintime_t to; /* precalculated timer period */
621 filt_timerexpire(void *knx)
624 struct kq_timer_cb_data *kc;
628 KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */
630 if ((kn->kn_flags & EV_ONESHOT) != 0)
635 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn,
636 PCPU_GET(cpuid), C_ABSOLUTE);
640 * data contains amount of time to sleep
643 filt_timerattach(struct knote *kn)
645 struct kq_timer_cb_data *kc;
647 unsigned int ncallouts;
649 if (kn->kn_sdata < 0)
651 if (kn->kn_sdata == 0 && (kn->kn_flags & EV_ONESHOT) == 0)
653 /* Only precision unit are supported in flags so far */
654 if ((kn->kn_sfflags & ~NOTE_TIMER_PRECMASK) != 0)
657 to = timer2sbintime(kn->kn_sdata, kn->kn_sfflags);
662 ncallouts = kq_ncallouts;
663 if (ncallouts >= kq_calloutmax)
665 } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1));
667 kn->kn_flags |= EV_CLEAR; /* automatically set */
668 kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */
669 kn->kn_ptr.p_v = kc = malloc(sizeof(*kc), M_KQUEUE, M_WAITOK);
670 callout_init(&kc->c, 1);
671 kc->next = to + sbinuptime();
673 callout_reset_sbt_on(&kc->c, kc->next, 0, filt_timerexpire, kn,
674 PCPU_GET(cpuid), C_ABSOLUTE);
680 filt_timerdetach(struct knote *kn)
682 struct kq_timer_cb_data *kc;
686 callout_drain(&kc->c);
688 old = atomic_fetchadd_int(&kq_ncallouts, -1);
689 KASSERT(old > 0, ("Number of callouts cannot become negative"));
690 kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */
694 filt_timer(struct knote *kn, long hint)
697 return (kn->kn_data != 0);
701 filt_userattach(struct knote *kn)
705 * EVFILT_USER knotes are not attached to anything in the kernel.
708 if (kn->kn_fflags & NOTE_TRIGGER)
716 filt_userdetach(__unused struct knote *kn)
720 * EVFILT_USER knotes are not attached to anything in the kernel.
725 filt_user(struct knote *kn, __unused long hint)
728 return (kn->kn_hookid);
732 filt_usertouch(struct knote *kn, struct kevent *kev, u_long type)
738 if (kev->fflags & NOTE_TRIGGER)
741 ffctrl = kev->fflags & NOTE_FFCTRLMASK;
742 kev->fflags &= NOTE_FFLAGSMASK;
748 kn->kn_sfflags &= kev->fflags;
752 kn->kn_sfflags |= kev->fflags;
756 kn->kn_sfflags = kev->fflags;
760 /* XXX Return error? */
763 kn->kn_sdata = kev->data;
764 if (kev->flags & EV_CLEAR) {
772 *kev = kn->kn_kevent;
773 kev->fflags = kn->kn_sfflags;
774 kev->data = kn->kn_sdata;
775 if (kn->kn_flags & EV_CLEAR) {
783 panic("filt_usertouch() - invalid type (%ld)", type);
789 sys_kqueue(struct thread *td, struct kqueue_args *uap)
792 return (kern_kqueue(td, 0));
796 kern_kqueue(struct thread *td, int flags)
798 struct filedesc *fdp;
803 fdp = td->td_proc->p_fd;
804 error = falloc(td, &fp, &fd, flags);
808 /* An extra reference on `fp' has been held for us by falloc(). */
809 kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO);
810 mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK);
811 TAILQ_INIT(&kq->kq_head);
813 knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock);
814 TASK_INIT(&kq->kq_task, 0, kqueue_task, kq);
817 TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list);
818 FILEDESC_XUNLOCK(fdp);
820 finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops);
823 td->td_retval[0] = fd;
829 kev_iovlen(int n, u_int kgio)
832 if (n < 0 || n >= kgio / sizeof(struct kevent))
834 return (n * sizeof(struct kevent));
837 #ifndef _SYS_SYSPROTO_H_
840 const struct kevent *changelist;
842 struct kevent *eventlist;
844 const struct timespec *timeout;
848 sys_kevent(struct thread *td, struct kevent_args *uap)
850 struct timespec ts, *tsp;
851 struct kevent_copyops k_ops = { uap,
858 struct uio *ktruioin = NULL;
859 struct uio *ktruioout = NULL;
863 if (uap->timeout != NULL) {
864 error = copyin(uap->timeout, &ts, sizeof(ts));
872 if (KTRPOINT(td, KTR_GENIO)) {
873 kgio = ktr_geniosize;
874 ktriov.iov_base = uap->changelist;
875 ktriov.iov_len = kev_iovlen(uap->nchanges, kgio);
876 ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1,
877 .uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ,
879 ktruioin = cloneuio(&ktruio);
880 ktriov.iov_base = uap->eventlist;
881 ktriov.iov_len = kev_iovlen(uap->nevents, kgio);
882 ktriov.iov_len = uap->nevents * sizeof(struct kevent);
883 ktruioout = cloneuio(&ktruio);
887 error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents,
891 if (ktruioin != NULL) {
892 ktruioin->uio_resid = kev_iovlen(uap->nchanges, kgio);
893 ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0);
894 ktruioout->uio_resid = kev_iovlen(td->td_retval[0], kgio);
895 ktrgenio(uap->fd, UIO_READ, ktruioout, error);
903 * Copy 'count' items into the destination list pointed to by uap->eventlist.
906 kevent_copyout(void *arg, struct kevent *kevp, int count)
908 struct kevent_args *uap;
911 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count));
912 uap = (struct kevent_args *)arg;
914 error = copyout(kevp, uap->eventlist, count * sizeof *kevp);
916 uap->eventlist += count;
921 * Copy 'count' items from the list pointed to by uap->changelist.
924 kevent_copyin(void *arg, struct kevent *kevp, int count)
926 struct kevent_args *uap;
929 KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count));
930 uap = (struct kevent_args *)arg;
932 error = copyin(uap->changelist, kevp, count * sizeof *kevp);
934 uap->changelist += count;
939 kern_kevent(struct thread *td, int fd, int nchanges, int nevents,
940 struct kevent_copyops *k_ops, const struct timespec *timeout)
946 cap_rights_init(&rights);
948 cap_rights_set(&rights, CAP_KQUEUE_CHANGE);
950 cap_rights_set(&rights, CAP_KQUEUE_EVENT);
951 error = fget(td, fd, &rights, &fp);
955 error = kern_kevent_fp(td, fp, nchanges, nevents, k_ops, timeout);
962 kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents,
963 struct kevent_copyops *k_ops, const struct timespec *timeout)
965 struct kevent keva[KQ_NEVENTS];
966 struct kevent *kevp, *changes;
968 int i, n, nerrors, error;
970 error = kqueue_acquire(fp, &kq);
976 while (nchanges > 0) {
977 n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges;
978 error = k_ops->k_copyin(k_ops->arg, keva, n);
982 for (i = 0; i < n; i++) {
986 kevp->flags &= ~EV_SYSFLAGS;
987 error = kqueue_register(kq, kevp, td, 1);
988 if (error || (kevp->flags & EV_RECEIPT)) {
990 kevp->flags = EV_ERROR;
992 (void) k_ops->k_copyout(k_ops->arg,
1004 td->td_retval[0] = nerrors;
1009 error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td);
1011 kqueue_release(kq, 0);
1016 kqueue_add_filteropts(int filt, struct filterops *filtops)
1021 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) {
1023 "trying to add a filterop that is out of range: %d is beyond %d\n",
1024 ~filt, EVFILT_SYSCOUNT);
1027 mtx_lock(&filterops_lock);
1028 if (sysfilt_ops[~filt].for_fop != &null_filtops &&
1029 sysfilt_ops[~filt].for_fop != NULL)
1032 sysfilt_ops[~filt].for_fop = filtops;
1033 sysfilt_ops[~filt].for_refcnt = 0;
1035 mtx_unlock(&filterops_lock);
1041 kqueue_del_filteropts(int filt)
1046 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
1049 mtx_lock(&filterops_lock);
1050 if (sysfilt_ops[~filt].for_fop == &null_filtops ||
1051 sysfilt_ops[~filt].for_fop == NULL)
1053 else if (sysfilt_ops[~filt].for_refcnt != 0)
1056 sysfilt_ops[~filt].for_fop = &null_filtops;
1057 sysfilt_ops[~filt].for_refcnt = 0;
1059 mtx_unlock(&filterops_lock);
1064 static struct filterops *
1065 kqueue_fo_find(int filt)
1068 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
1071 mtx_lock(&filterops_lock);
1072 sysfilt_ops[~filt].for_refcnt++;
1073 if (sysfilt_ops[~filt].for_fop == NULL)
1074 sysfilt_ops[~filt].for_fop = &null_filtops;
1075 mtx_unlock(&filterops_lock);
1077 return sysfilt_ops[~filt].for_fop;
1081 kqueue_fo_release(int filt)
1084 if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
1087 mtx_lock(&filterops_lock);
1088 KASSERT(sysfilt_ops[~filt].for_refcnt > 0,
1089 ("filter object refcount not valid on release"));
1090 sysfilt_ops[~filt].for_refcnt--;
1091 mtx_unlock(&filterops_lock);
1095 * A ref to kq (obtained via kqueue_acquire) must be held. waitok will
1096 * influence if memory allocation should wait. Make sure it is 0 if you
1100 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok)
1102 struct filterops *fops;
1104 struct knote *kn, *tkn;
1105 cap_rights_t rights;
1106 int error, filt, event;
1107 int haskqglobal, filedesc_unlock;
1113 filedesc_unlock = 0;
1116 fops = kqueue_fo_find(filt);
1120 tkn = knote_alloc(waitok); /* prevent waiting with locks */
1124 KASSERT(td != NULL, ("td is NULL"));
1125 if (kev->ident > INT_MAX)
1128 error = fget(td, kev->ident,
1129 cap_rights_init(&rights, CAP_EVENT), &fp);
1133 if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops,
1134 kev->ident, 0) != 0) {
1138 error = kqueue_expand(kq, fops, kev->ident, waitok);
1144 if (fp->f_type == DTYPE_KQUEUE) {
1146 * If we add some intelligence about what we are doing,
1147 * we should be able to support events on ourselves.
1148 * We need to know when we are doing this to prevent
1149 * getting both the knlist lock and the kq lock since
1150 * they are the same thing.
1152 if (fp->f_data == kq) {
1158 * Pre-lock the filedesc before the global
1159 * lock mutex, see the comment in
1162 FILEDESC_XLOCK(td->td_proc->p_fd);
1163 filedesc_unlock = 1;
1164 KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
1168 if (kev->ident < kq->kq_knlistsize) {
1169 SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link)
1170 if (kev->filter == kn->kn_filter)
1174 if ((kev->flags & EV_ADD) == EV_ADD)
1175 kqueue_expand(kq, fops, kev->ident, waitok);
1180 * If possible, find an existing knote to use for this kevent.
1182 if (kev->filter == EVFILT_PROC &&
1183 (kev->flags & (EV_FLAG1 | EV_FLAG2)) != 0) {
1184 /* This is an internal creation of a process tracking
1185 * note. Don't attempt to coalesce this with an
1189 } else if (kq->kq_knhashmask != 0) {
1192 list = &kq->kq_knhash[
1193 KN_HASH((u_long)kev->ident, kq->kq_knhashmask)];
1194 SLIST_FOREACH(kn, list, kn_link)
1195 if (kev->ident == kn->kn_id &&
1196 kev->filter == kn->kn_filter)
1201 /* knote is in the process of changing, wait for it to stabilize. */
1202 if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1203 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1204 if (filedesc_unlock) {
1205 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1206 filedesc_unlock = 0;
1208 kq->kq_state |= KQ_FLUXWAIT;
1209 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0);
1218 * kn now contains the matching knote, or NULL if no match
1221 if (kev->flags & EV_ADD) {
1233 * apply reference counts to knote structure, and
1234 * do not release it at the end of this routine.
1239 kn->kn_sfflags = kev->fflags;
1240 kn->kn_sdata = kev->data;
1243 kn->kn_kevent = *kev;
1244 kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE |
1245 EV_ENABLE | EV_DISABLE);
1246 kn->kn_status = KN_INFLUX|KN_DETACHED;
1248 error = knote_attach(kn, kq);
1255 if ((error = kn->kn_fop->f_attach(kn)) != 0) {
1262 /* No matching knote and the EV_ADD flag is not set. */
1269 if (kev->flags & EV_DELETE) {
1270 kn->kn_status |= KN_INFLUX;
1272 if (!(kn->kn_status & KN_DETACHED))
1273 kn->kn_fop->f_detach(kn);
1279 * The user may change some filter values after the initial EV_ADD,
1280 * but doing so will not reset any filter which has already been
1283 kn->kn_status |= KN_INFLUX | KN_SCAN;
1286 kn->kn_kevent.udata = kev->udata;
1287 if (!fops->f_isfd && fops->f_touch != NULL) {
1288 fops->f_touch(kn, kev, EVENT_REGISTER);
1290 kn->kn_sfflags = kev->fflags;
1291 kn->kn_sdata = kev->data;
1295 * We can get here with kn->kn_knlist == NULL. This can happen when
1296 * the initial attach event decides that the event is "completed"
1297 * already. i.e. filt_procattach is called on a zombie process. It
1298 * will call filt_proc which will remove it from the list, and NULL
1302 event = kn->kn_fop->f_event(kn, 0);
1305 KNOTE_ACTIVATE(kn, 1);
1306 kn->kn_status &= ~(KN_INFLUX | KN_SCAN);
1309 if ((kev->flags & EV_DISABLE) &&
1310 ((kn->kn_status & KN_DISABLED) == 0)) {
1311 kn->kn_status |= KN_DISABLED;
1314 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
1315 kn->kn_status &= ~KN_DISABLED;
1316 if ((kn->kn_status & KN_ACTIVE) &&
1317 ((kn->kn_status & KN_QUEUED) == 0))
1323 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1324 if (filedesc_unlock)
1325 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1331 kqueue_fo_release(filt);
1336 kqueue_acquire(struct file *fp, struct kqueue **kqp)
1344 if (fp->f_type != DTYPE_KQUEUE || kq == NULL)
1348 if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) {
1359 kqueue_release(struct kqueue *kq, int locked)
1366 if (kq->kq_refcnt == 1)
1367 wakeup(&kq->kq_refcnt);
1373 kqueue_schedtask(struct kqueue *kq)
1377 KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN),
1378 ("scheduling kqueue task while draining"));
1380 if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) {
1381 taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task);
1382 kq->kq_state |= KQ_TASKSCHED;
1387 * Expand the kq to make sure we have storage for fops/ident pair.
1389 * Return 0 on success (or no work necessary), return errno on failure.
1391 * Not calling hashinit w/ waitok (proper malloc flag) should be safe.
1392 * If kqueue_register is called from a non-fd context, there usually/should
1396 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
1399 struct klist *list, *tmp_knhash, *to_free;
1400 u_long tmp_knhashmask;
1403 int mflag = waitok ? M_WAITOK : M_NOWAIT;
1410 if (kq->kq_knlistsize <= fd) {
1411 size = kq->kq_knlistsize;
1414 list = malloc(size * sizeof(*list), M_KQUEUE, mflag);
1418 if (kq->kq_knlistsize > fd) {
1422 if (kq->kq_knlist != NULL) {
1423 bcopy(kq->kq_knlist, list,
1424 kq->kq_knlistsize * sizeof(*list));
1425 to_free = kq->kq_knlist;
1426 kq->kq_knlist = NULL;
1428 bzero((caddr_t)list +
1429 kq->kq_knlistsize * sizeof(*list),
1430 (size - kq->kq_knlistsize) * sizeof(*list));
1431 kq->kq_knlistsize = size;
1432 kq->kq_knlist = list;
1437 if (kq->kq_knhashmask == 0) {
1438 tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
1440 if (tmp_knhash == NULL)
1443 if (kq->kq_knhashmask == 0) {
1444 kq->kq_knhash = tmp_knhash;
1445 kq->kq_knhashmask = tmp_knhashmask;
1447 to_free = tmp_knhash;
1452 free(to_free, M_KQUEUE);
1459 kqueue_task(void *arg, int pending)
1467 KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
1470 KNOTE_LOCKED(&kq->kq_sel.si_note, 0);
1472 kq->kq_state &= ~KQ_TASKSCHED;
1473 if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) {
1474 wakeup(&kq->kq_state);
1477 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1481 * Scan, update kn_data (if not ONESHOT), and copyout triggered events.
1482 * We treat KN_MARKER knotes as if they are INFLUX.
1485 kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops,
1486 const struct timespec *tsp, struct kevent *keva, struct thread *td)
1488 struct kevent *kevp;
1489 struct knote *kn, *marker;
1490 sbintime_t asbt, rsbt;
1491 int count, error, haskqglobal, influx, nkev, touch;
1503 if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 ||
1504 tsp->tv_nsec >= 1000000000) {
1508 if (timespecisset(tsp)) {
1509 if (tsp->tv_sec <= INT32_MAX) {
1510 rsbt = tstosbt(*tsp);
1511 if (TIMESEL(&asbt, rsbt))
1512 asbt += tc_tick_sbt;
1513 if (asbt <= SBT_MAX - rsbt)
1517 rsbt >>= tc_precexp;
1524 marker = knote_alloc(1);
1525 if (marker == NULL) {
1529 marker->kn_status = KN_MARKER;
1534 if (kq->kq_count == 0) {
1536 error = EWOULDBLOCK;
1538 kq->kq_state |= KQ_SLEEP;
1539 error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH,
1540 "kqread", asbt, rsbt, C_ABSOLUTE);
1544 /* don't restart after signals... */
1545 if (error == ERESTART)
1547 else if (error == EWOULDBLOCK)
1552 TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe);
1556 kn = TAILQ_FIRST(&kq->kq_head);
1558 if ((kn->kn_status == KN_MARKER && kn != marker) ||
1559 (kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1564 kq->kq_state |= KQ_FLUXWAIT;
1565 error = msleep(kq, &kq->kq_lock, PSOCK,
1570 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
1571 if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) {
1572 kn->kn_status &= ~KN_QUEUED;
1578 if (count == maxevents)
1582 KASSERT((kn->kn_status & KN_INFLUX) == 0,
1583 ("KN_INFLUX set when not suppose to be"));
1585 if ((kn->kn_flags & EV_DROP) == EV_DROP) {
1586 kn->kn_status &= ~KN_QUEUED;
1587 kn->kn_status |= KN_INFLUX;
1591 * We don't need to lock the list since we've marked
1594 if (!(kn->kn_status & KN_DETACHED))
1595 kn->kn_fop->f_detach(kn);
1599 } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) {
1600 kn->kn_status &= ~KN_QUEUED;
1601 kn->kn_status |= KN_INFLUX;
1605 * We don't need to lock the list since we've marked
1608 *kevp = kn->kn_kevent;
1609 if (!(kn->kn_status & KN_DETACHED))
1610 kn->kn_fop->f_detach(kn);
1615 kn->kn_status |= KN_INFLUX | KN_SCAN;
1617 if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE)
1618 KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
1620 if (kn->kn_fop->f_event(kn, 0) == 0) {
1622 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1624 ~(KN_QUEUED | KN_ACTIVE | KN_INFLUX |
1631 touch = (!kn->kn_fop->f_isfd &&
1632 kn->kn_fop->f_touch != NULL);
1634 kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS);
1636 *kevp = kn->kn_kevent;
1638 KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
1639 if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) {
1641 * Manually clear knotes who weren't
1644 if (touch == 0 && kn->kn_flags & EV_CLEAR) {
1648 if (kn->kn_flags & EV_DISPATCH)
1649 kn->kn_status |= KN_DISABLED;
1650 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
1653 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
1655 kn->kn_status &= ~(KN_INFLUX | KN_SCAN);
1660 /* we are returning a copy to the user */
1665 if (nkev == KQ_NEVENTS) {
1668 error = k_ops->k_copyout(k_ops->arg, keva, nkev);
1676 TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe);
1684 error = k_ops->k_copyout(k_ops->arg, keva, nkev);
1685 td->td_retval[0] = maxevents - count;
1691 * This could be expanded to call kqueue_scan, if desired.
1695 kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
1696 int flags, struct thread *td)
1703 kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
1704 int flags, struct thread *td)
1711 kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1720 kqueue_ioctl(struct file *fp, u_long cmd, void *data,
1721 struct ucred *active_cred, struct thread *td)
1724 * Enabling sigio causes two major problems:
1725 * 1) infinite recursion:
1726 * Synopsys: kevent is being used to track signals and have FIOASYNC
1727 * set. On receipt of a signal this will cause a kqueue to recurse
1728 * into itself over and over. Sending the sigio causes the kqueue
1729 * to become ready, which in turn posts sigio again, forever.
1730 * Solution: this can be solved by setting a flag in the kqueue that
1731 * we have a SIGIO in progress.
1732 * 2) locking problems:
1733 * Synopsys: Kqueue is a leaf subsystem, but adding signalling puts
1734 * us above the proc and pgrp locks.
1735 * Solution: Post a signal using an async mechanism, being sure to
1736 * record a generation count in the delivery so that we do not deliver
1737 * a signal to the wrong process.
1739 * Note, these two mechanisms are somewhat mutually exclusive!
1748 kq->kq_state |= KQ_ASYNC;
1750 kq->kq_state &= ~KQ_ASYNC;
1755 return (fsetown(*(int *)data, &kq->kq_sigio));
1758 *(int *)data = fgetown(&kq->kq_sigio);
1768 kqueue_poll(struct file *fp, int events, struct ucred *active_cred,
1775 if ((error = kqueue_acquire(fp, &kq)))
1779 if (events & (POLLIN | POLLRDNORM)) {
1781 revents |= events & (POLLIN | POLLRDNORM);
1783 selrecord(td, &kq->kq_sel);
1784 if (SEL_WAITING(&kq->kq_sel))
1785 kq->kq_state |= KQ_SEL;
1788 kqueue_release(kq, 1);
1795 kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
1799 bzero((void *)st, sizeof *st);
1801 * We no longer return kq_count because the unlocked value is useless.
1802 * If you spent all this time getting the count, why not spend your
1803 * syscall better by calling kevent?
1805 * XXX - This is needed for libc_r.
1807 st->st_mode = S_IFIFO;
1813 kqueue_close(struct file *fp, struct thread *td)
1815 struct kqueue *kq = fp->f_data;
1816 struct filedesc *fdp;
1820 int filedesc_unlock;
1822 if ((error = kqueue_acquire(fp, &kq)))
1825 filedesc_unlock = 0;
1828 KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING,
1829 ("kqueue already closing"));
1830 kq->kq_state |= KQ_CLOSING;
1831 if (kq->kq_refcnt > 1)
1832 msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0);
1834 KASSERT(kq->kq_refcnt == 1, ("other refs are out there!"));
1837 KASSERT(knlist_empty(&kq->kq_sel.si_note),
1838 ("kqueue's knlist not empty"));
1840 for (i = 0; i < kq->kq_knlistsize; i++) {
1841 while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) {
1842 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1843 kq->kq_state |= KQ_FLUXWAIT;
1844 msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0);
1847 kn->kn_status |= KN_INFLUX;
1849 if (!(kn->kn_status & KN_DETACHED))
1850 kn->kn_fop->f_detach(kn);
1855 if (kq->kq_knhashmask != 0) {
1856 for (i = 0; i <= kq->kq_knhashmask; i++) {
1857 while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) {
1858 if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
1859 kq->kq_state |= KQ_FLUXWAIT;
1860 msleep(kq, &kq->kq_lock, PSOCK,
1864 kn->kn_status |= KN_INFLUX;
1866 if (!(kn->kn_status & KN_DETACHED))
1867 kn->kn_fop->f_detach(kn);
1874 if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) {
1875 kq->kq_state |= KQ_TASKDRAIN;
1876 msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0);
1879 if ((kq->kq_state & KQ_SEL) == KQ_SEL) {
1880 selwakeuppri(&kq->kq_sel, PSOCK);
1881 if (!SEL_WAITING(&kq->kq_sel))
1882 kq->kq_state &= ~KQ_SEL;
1888 * We could be called due to the knote_drop() doing fdrop(),
1889 * called from kqueue_register(). In this case the global
1890 * lock is owned, and filedesc sx is locked before, to not
1891 * take the sleepable lock after non-sleepable.
1893 if (!sx_xlocked(FILEDESC_LOCK(fdp))) {
1894 FILEDESC_XLOCK(fdp);
1895 filedesc_unlock = 1;
1897 filedesc_unlock = 0;
1898 TAILQ_REMOVE(&fdp->fd_kqlist, kq, kq_list);
1899 if (filedesc_unlock)
1900 FILEDESC_XUNLOCK(fdp);
1902 seldrain(&kq->kq_sel);
1903 knlist_destroy(&kq->kq_sel.si_note);
1904 mtx_destroy(&kq->kq_lock);
1907 if (kq->kq_knhash != NULL)
1908 free(kq->kq_knhash, M_KQUEUE);
1909 if (kq->kq_knlist != NULL)
1910 free(kq->kq_knlist, M_KQUEUE);
1912 funsetown(&kq->kq_sigio);
1920 kqueue_wakeup(struct kqueue *kq)
1924 if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) {
1925 kq->kq_state &= ~KQ_SLEEP;
1928 if ((kq->kq_state & KQ_SEL) == KQ_SEL) {
1929 selwakeuppri(&kq->kq_sel, PSOCK);
1930 if (!SEL_WAITING(&kq->kq_sel))
1931 kq->kq_state &= ~KQ_SEL;
1933 if (!knlist_empty(&kq->kq_sel.si_note))
1934 kqueue_schedtask(kq);
1935 if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) {
1936 pgsigio(&kq->kq_sigio, SIGIO, 0);
1941 * Walk down a list of knotes, activating them if their event has triggered.
1943 * There is a possibility to optimize in the case of one kq watching another.
1944 * Instead of scheduling a task to wake it up, you could pass enough state
1945 * down the chain to make up the parent kqueue. Make this code functional
1949 knote(struct knlist *list, long hint, int lockflags)
1952 struct knote *kn, *tkn;
1959 KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED);
1961 if ((lockflags & KNF_LISTLOCKED) == 0)
1962 list->kl_lock(list->kl_lockarg);
1965 * If we unlock the list lock (and set KN_INFLUX), we can
1966 * eliminate the kqueue scheduling, but this will introduce
1967 * four lock/unlock's for each knote to test. Also, marker
1968 * would be needed to keep iteration position, since filters
1969 * or other threads could remove events.
1971 SLIST_FOREACH_SAFE(kn, &list->kl_list, kn_selnext, tkn) {
1974 if ((kn->kn_status & (KN_INFLUX | KN_SCAN)) == KN_INFLUX) {
1976 * Do not process the influx notes, except for
1977 * the influx coming from the kq unlock in the
1978 * kqueue_scan(). In the later case, we do
1979 * not interfere with the scan, since the code
1980 * fragment in kqueue_scan() locks the knlist,
1981 * and cannot proceed until we finished.
1984 } else if ((lockflags & KNF_NOKQLOCK) != 0) {
1985 own_influx = (kn->kn_status & KN_INFLUX) == 0;
1987 kn->kn_status |= KN_INFLUX;
1989 error = kn->kn_fop->f_event(kn, hint);
1992 kn->kn_status &= ~KN_INFLUX;
1994 KNOTE_ACTIVATE(kn, 1);
1997 kn->kn_status |= KN_HASKQLOCK;
1998 if (kn->kn_fop->f_event(kn, hint))
1999 KNOTE_ACTIVATE(kn, 1);
2000 kn->kn_status &= ~KN_HASKQLOCK;
2004 if ((lockflags & KNF_LISTLOCKED) == 0)
2005 list->kl_unlock(list->kl_lockarg);
2009 * add a knote to a knlist
2012 knlist_add(struct knlist *knl, struct knote *kn, int islocked)
2014 KNL_ASSERT_LOCK(knl, islocked);
2015 KQ_NOTOWNED(kn->kn_kq);
2016 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) ==
2017 (KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED"));
2019 knl->kl_lock(knl->kl_lockarg);
2020 SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext);
2022 knl->kl_unlock(knl->kl_lockarg);
2024 kn->kn_knlist = knl;
2025 kn->kn_status &= ~KN_DETACHED;
2026 KQ_UNLOCK(kn->kn_kq);
2030 knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked)
2032 KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked"));
2033 KNL_ASSERT_LOCK(knl, knlislocked);
2034 mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED);
2036 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX,
2037 ("knlist_remove called w/o knote being KN_INFLUX or already removed"));
2039 knl->kl_lock(knl->kl_lockarg);
2040 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext);
2041 kn->kn_knlist = NULL;
2043 knl->kl_unlock(knl->kl_lockarg);
2046 kn->kn_status |= KN_DETACHED;
2048 KQ_UNLOCK(kn->kn_kq);
2052 * remove knote from the specified knlist
2055 knlist_remove(struct knlist *knl, struct knote *kn, int islocked)
2058 knlist_remove_kq(knl, kn, islocked, 0);
2062 * remove knote from the specified knlist while in f_event handler.
2065 knlist_remove_inevent(struct knlist *knl, struct knote *kn)
2068 knlist_remove_kq(knl, kn, 1,
2069 (kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK);
2073 knlist_empty(struct knlist *knl)
2076 KNL_ASSERT_LOCKED(knl);
2077 return (SLIST_EMPTY(&knl->kl_list));
2080 static struct mtx knlist_lock;
2081 MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects",
2083 static void knlist_mtx_lock(void *arg);
2084 static void knlist_mtx_unlock(void *arg);
2087 knlist_mtx_lock(void *arg)
2090 mtx_lock((struct mtx *)arg);
2094 knlist_mtx_unlock(void *arg)
2097 mtx_unlock((struct mtx *)arg);
2101 knlist_mtx_assert_locked(void *arg)
2104 mtx_assert((struct mtx *)arg, MA_OWNED);
2108 knlist_mtx_assert_unlocked(void *arg)
2111 mtx_assert((struct mtx *)arg, MA_NOTOWNED);
2115 knlist_rw_rlock(void *arg)
2118 rw_rlock((struct rwlock *)arg);
2122 knlist_rw_runlock(void *arg)
2125 rw_runlock((struct rwlock *)arg);
2129 knlist_rw_assert_locked(void *arg)
2132 rw_assert((struct rwlock *)arg, RA_LOCKED);
2136 knlist_rw_assert_unlocked(void *arg)
2139 rw_assert((struct rwlock *)arg, RA_UNLOCKED);
2143 knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
2144 void (*kl_unlock)(void *),
2145 void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *))
2149 knl->kl_lockarg = &knlist_lock;
2151 knl->kl_lockarg = lock;
2153 if (kl_lock == NULL)
2154 knl->kl_lock = knlist_mtx_lock;
2156 knl->kl_lock = kl_lock;
2157 if (kl_unlock == NULL)
2158 knl->kl_unlock = knlist_mtx_unlock;
2160 knl->kl_unlock = kl_unlock;
2161 if (kl_assert_locked == NULL)
2162 knl->kl_assert_locked = knlist_mtx_assert_locked;
2164 knl->kl_assert_locked = kl_assert_locked;
2165 if (kl_assert_unlocked == NULL)
2166 knl->kl_assert_unlocked = knlist_mtx_assert_unlocked;
2168 knl->kl_assert_unlocked = kl_assert_unlocked;
2170 SLIST_INIT(&knl->kl_list);
2174 knlist_init_mtx(struct knlist *knl, struct mtx *lock)
2177 knlist_init(knl, lock, NULL, NULL, NULL, NULL);
2181 knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock)
2184 knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock,
2185 knlist_rw_assert_locked, knlist_rw_assert_unlocked);
2189 knlist_destroy(struct knlist *knl)
2192 KASSERT(KNLIST_EMPTY(knl),
2193 ("destroying knlist %p with knotes on it", knl));
2197 * Even if we are locked, we may need to drop the lock to allow any influx
2198 * knotes time to "settle".
2201 knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn)
2203 struct knote *kn, *kn2;
2207 KNL_ASSERT_LOCKED(knl);
2209 KNL_ASSERT_UNLOCKED(knl);
2210 again: /* need to reacquire lock since we have dropped it */
2211 knl->kl_lock(knl->kl_lockarg);
2214 SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) {
2217 if ((kn->kn_status & KN_INFLUX)) {
2221 knlist_remove_kq(knl, kn, 1, 1);
2223 kn->kn_status |= KN_INFLUX | KN_DETACHED;
2227 /* Make sure cleared knotes disappear soon */
2228 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
2234 if (!SLIST_EMPTY(&knl->kl_list)) {
2235 /* there are still KN_INFLUX remaining */
2236 kn = SLIST_FIRST(&knl->kl_list);
2239 KASSERT(kn->kn_status & KN_INFLUX,
2240 ("knote removed w/o list lock"));
2241 knl->kl_unlock(knl->kl_lockarg);
2242 kq->kq_state |= KQ_FLUXWAIT;
2243 msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0);
2249 KNL_ASSERT_LOCKED(knl);
2251 knl->kl_unlock(knl->kl_lockarg);
2252 KNL_ASSERT_UNLOCKED(knl);
2257 * Remove all knotes referencing a specified fd must be called with FILEDESC
2258 * lock. This prevents a race where a new fd comes along and occupies the
2259 * entry and we attach a knote to the fd.
2262 knote_fdclose(struct thread *td, int fd)
2264 struct filedesc *fdp = td->td_proc->p_fd;
2269 FILEDESC_XLOCK_ASSERT(fdp);
2272 * We shouldn't have to worry about new kevents appearing on fd
2273 * since filedesc is locked.
2275 TAILQ_FOREACH(kq, &fdp->fd_kqlist, kq_list) {
2280 while (kq->kq_knlistsize > fd &&
2281 (kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) {
2282 if (kn->kn_status & KN_INFLUX) {
2283 /* someone else might be waiting on our knote */
2286 kq->kq_state |= KQ_FLUXWAIT;
2287 msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0);
2290 kn->kn_status |= KN_INFLUX;
2292 if (!(kn->kn_status & KN_DETACHED))
2293 kn->kn_fop->f_detach(kn);
2303 knote_attach(struct knote *kn, struct kqueue *kq)
2307 KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX"));
2310 if (kn->kn_fop->f_isfd) {
2311 if (kn->kn_id >= kq->kq_knlistsize)
2313 list = &kq->kq_knlist[kn->kn_id];
2315 if (kq->kq_knhash == NULL)
2317 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
2319 SLIST_INSERT_HEAD(list, kn, kn_link);
2324 * knote must already have been detached using the f_detach method.
2325 * no lock need to be held, it is assumed that the KN_INFLUX flag is set
2326 * to prevent other removal.
2329 knote_drop(struct knote *kn, struct thread *td)
2337 KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX,
2338 ("knote_drop called without KN_INFLUX set in kn_status"));
2341 if (kn->kn_fop->f_isfd)
2342 list = &kq->kq_knlist[kn->kn_id];
2344 list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
2346 if (!SLIST_EMPTY(list))
2347 SLIST_REMOVE(list, kn, knote, kn_link);
2348 if (kn->kn_status & KN_QUEUED)
2352 if (kn->kn_fop->f_isfd) {
2353 fdrop(kn->kn_fp, td);
2356 kqueue_fo_release(kn->kn_kevent.filter);
2362 knote_enqueue(struct knote *kn)
2364 struct kqueue *kq = kn->kn_kq;
2366 KQ_OWNED(kn->kn_kq);
2367 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
2369 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
2370 kn->kn_status |= KN_QUEUED;
2376 knote_dequeue(struct knote *kn)
2378 struct kqueue *kq = kn->kn_kq;
2380 KQ_OWNED(kn->kn_kq);
2381 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
2383 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
2384 kn->kn_status &= ~KN_QUEUED;
2392 knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL,
2393 NULL, NULL, UMA_ALIGN_PTR, 0);
2395 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL);
2397 static struct knote *
2398 knote_alloc(int waitok)
2400 return ((struct knote *)uma_zalloc(knote_zone,
2401 (waitok ? M_WAITOK : M_NOWAIT)|M_ZERO));
2405 knote_free(struct knote *kn)
2408 uma_zfree(knote_zone, kn);
2412 * Register the kev w/ the kq specified by fd.
2415 kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok)
2419 cap_rights_t rights;
2422 error = fget(td, fd, cap_rights_init(&rights, CAP_KQUEUE_CHANGE), &fp);
2425 if ((error = kqueue_acquire(fp, &kq)) != 0)
2428 error = kqueue_register(kq, kev, td, waitok);
2429 kqueue_release(kq, 0);