In order to get some coverage of C11 atomics in kernelspace, switch at least one piece of code in kernelspace to use C11 atomics instead of <machine/atomic.h>. While there, slightly improve the code by adding an assertion to prevent the use count from going negative.
2238 lines
51 KiB
C
2238 lines
51 KiB
C
/*-
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* Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
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* Copyright 2004 John-Mark Gurney <jmg@FreeBSD.org>
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* Copyright (c) 2009 Apple, Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_ktrace.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/capability.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/rwlock.h>
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#include <sys/proc.h>
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#include <sys/malloc.h>
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#include <sys/unistd.h>
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#include <sys/file.h>
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#include <sys/filedesc.h>
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#include <sys/filio.h>
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#include <sys/fcntl.h>
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#include <sys/kthread.h>
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#include <sys/selinfo.h>
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#include <sys/stdatomic.h>
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#include <sys/queue.h>
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#include <sys/event.h>
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#include <sys/eventvar.h>
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#include <sys/poll.h>
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#include <sys/protosw.h>
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#include <sys/sigio.h>
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#include <sys/signalvar.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/stat.h>
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#include <sys/sysctl.h>
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#include <sys/sysproto.h>
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#include <sys/syscallsubr.h>
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#include <sys/taskqueue.h>
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#include <sys/uio.h>
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#ifdef KTRACE
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#include <sys/ktrace.h>
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#endif
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#include <vm/uma.h>
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static MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
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/*
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* This lock is used if multiple kq locks are required. This possibly
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* should be made into a per proc lock.
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*/
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static struct mtx kq_global;
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MTX_SYSINIT(kq_global, &kq_global, "kqueue order", MTX_DEF);
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#define KQ_GLOBAL_LOCK(lck, haslck) do { \
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if (!haslck) \
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mtx_lock(lck); \
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haslck = 1; \
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} while (0)
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#define KQ_GLOBAL_UNLOCK(lck, haslck) do { \
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if (haslck) \
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mtx_unlock(lck); \
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haslck = 0; \
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} while (0)
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TASKQUEUE_DEFINE_THREAD(kqueue);
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static int kevent_copyout(void *arg, struct kevent *kevp, int count);
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static int kevent_copyin(void *arg, struct kevent *kevp, int count);
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static int kqueue_register(struct kqueue *kq, struct kevent *kev,
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struct thread *td, int waitok);
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static int kqueue_acquire(struct file *fp, struct kqueue **kqp);
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static void kqueue_release(struct kqueue *kq, int locked);
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static int kqueue_expand(struct kqueue *kq, struct filterops *fops,
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uintptr_t ident, int waitok);
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static void kqueue_task(void *arg, int pending);
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static int kqueue_scan(struct kqueue *kq, int maxevents,
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struct kevent_copyops *k_ops,
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const struct timespec *timeout,
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struct kevent *keva, struct thread *td);
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static void kqueue_wakeup(struct kqueue *kq);
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static struct filterops *kqueue_fo_find(int filt);
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static void kqueue_fo_release(int filt);
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static fo_rdwr_t kqueue_read;
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static fo_rdwr_t kqueue_write;
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static fo_truncate_t kqueue_truncate;
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static fo_ioctl_t kqueue_ioctl;
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static fo_poll_t kqueue_poll;
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static fo_kqfilter_t kqueue_kqfilter;
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static fo_stat_t kqueue_stat;
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static fo_close_t kqueue_close;
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static struct fileops kqueueops = {
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.fo_read = kqueue_read,
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.fo_write = kqueue_write,
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.fo_truncate = kqueue_truncate,
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.fo_ioctl = kqueue_ioctl,
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.fo_poll = kqueue_poll,
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.fo_kqfilter = kqueue_kqfilter,
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.fo_stat = kqueue_stat,
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.fo_close = kqueue_close,
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.fo_chmod = invfo_chmod,
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.fo_chown = invfo_chown,
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};
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static int knote_attach(struct knote *kn, struct kqueue *kq);
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static void knote_drop(struct knote *kn, struct thread *td);
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static void knote_enqueue(struct knote *kn);
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static void knote_dequeue(struct knote *kn);
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static void knote_init(void);
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static struct knote *knote_alloc(int waitok);
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static void knote_free(struct knote *kn);
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static void filt_kqdetach(struct knote *kn);
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static int filt_kqueue(struct knote *kn, long hint);
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static int filt_procattach(struct knote *kn);
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static void filt_procdetach(struct knote *kn);
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static int filt_proc(struct knote *kn, long hint);
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static int filt_fileattach(struct knote *kn);
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static void filt_timerexpire(void *knx);
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static int filt_timerattach(struct knote *kn);
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static void filt_timerdetach(struct knote *kn);
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static int filt_timer(struct knote *kn, long hint);
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static int filt_userattach(struct knote *kn);
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static void filt_userdetach(struct knote *kn);
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static int filt_user(struct knote *kn, long hint);
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static void filt_usertouch(struct knote *kn, struct kevent *kev,
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u_long type);
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static struct filterops file_filtops = {
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.f_isfd = 1,
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.f_attach = filt_fileattach,
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};
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static struct filterops kqread_filtops = {
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.f_isfd = 1,
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.f_detach = filt_kqdetach,
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.f_event = filt_kqueue,
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};
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/* XXX - move to kern_proc.c? */
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static struct filterops proc_filtops = {
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.f_isfd = 0,
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.f_attach = filt_procattach,
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.f_detach = filt_procdetach,
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.f_event = filt_proc,
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};
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static struct filterops timer_filtops = {
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.f_isfd = 0,
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.f_attach = filt_timerattach,
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.f_detach = filt_timerdetach,
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.f_event = filt_timer,
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};
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static struct filterops user_filtops = {
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.f_attach = filt_userattach,
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.f_detach = filt_userdetach,
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.f_event = filt_user,
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.f_touch = filt_usertouch,
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};
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static uma_zone_t knote_zone;
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static atomic_uint kq_ncallouts = ATOMIC_VAR_INIT(0);
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static unsigned int kq_calloutmax = 4 * 1024;
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SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
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&kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
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/* XXX - ensure not KN_INFLUX?? */
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#define KNOTE_ACTIVATE(kn, islock) do { \
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if ((islock)) \
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mtx_assert(&(kn)->kn_kq->kq_lock, MA_OWNED); \
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else \
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KQ_LOCK((kn)->kn_kq); \
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(kn)->kn_status |= KN_ACTIVE; \
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if (((kn)->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
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knote_enqueue((kn)); \
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if (!(islock)) \
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KQ_UNLOCK((kn)->kn_kq); \
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} while(0)
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#define KQ_LOCK(kq) do { \
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mtx_lock(&(kq)->kq_lock); \
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} while (0)
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#define KQ_FLUX_WAKEUP(kq) do { \
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if (((kq)->kq_state & KQ_FLUXWAIT) == KQ_FLUXWAIT) { \
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(kq)->kq_state &= ~KQ_FLUXWAIT; \
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wakeup((kq)); \
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} \
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} while (0)
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#define KQ_UNLOCK_FLUX(kq) do { \
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KQ_FLUX_WAKEUP(kq); \
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mtx_unlock(&(kq)->kq_lock); \
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} while (0)
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#define KQ_UNLOCK(kq) do { \
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mtx_unlock(&(kq)->kq_lock); \
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} while (0)
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#define KQ_OWNED(kq) do { \
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mtx_assert(&(kq)->kq_lock, MA_OWNED); \
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} while (0)
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#define KQ_NOTOWNED(kq) do { \
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mtx_assert(&(kq)->kq_lock, MA_NOTOWNED); \
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} while (0)
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#define KN_LIST_LOCK(kn) do { \
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if (kn->kn_knlist != NULL) \
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kn->kn_knlist->kl_lock(kn->kn_knlist->kl_lockarg); \
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} while (0)
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#define KN_LIST_UNLOCK(kn) do { \
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if (kn->kn_knlist != NULL) \
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kn->kn_knlist->kl_unlock(kn->kn_knlist->kl_lockarg); \
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} while (0)
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#define KNL_ASSERT_LOCK(knl, islocked) do { \
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if (islocked) \
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KNL_ASSERT_LOCKED(knl); \
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else \
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KNL_ASSERT_UNLOCKED(knl); \
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} while (0)
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#ifdef INVARIANTS
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#define KNL_ASSERT_LOCKED(knl) do { \
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knl->kl_assert_locked((knl)->kl_lockarg); \
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} while (0)
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#define KNL_ASSERT_UNLOCKED(knl) do { \
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knl->kl_assert_unlocked((knl)->kl_lockarg); \
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} while (0)
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#else /* !INVARIANTS */
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#define KNL_ASSERT_LOCKED(knl) do {} while(0)
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#define KNL_ASSERT_UNLOCKED(knl) do {} while (0)
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#endif /* INVARIANTS */
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#define KN_HASHSIZE 64 /* XXX should be tunable */
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#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
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static int
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filt_nullattach(struct knote *kn)
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{
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return (ENXIO);
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};
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struct filterops null_filtops = {
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.f_isfd = 0,
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.f_attach = filt_nullattach,
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};
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/* XXX - make SYSINIT to add these, and move into respective modules. */
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extern struct filterops sig_filtops;
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extern struct filterops fs_filtops;
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/*
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* Table for for all system-defined filters.
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*/
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static struct mtx filterops_lock;
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MTX_SYSINIT(kqueue_filterops, &filterops_lock, "protect sysfilt_ops",
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MTX_DEF);
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static struct {
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struct filterops *for_fop;
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int for_refcnt;
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} sysfilt_ops[EVFILT_SYSCOUNT] = {
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{ &file_filtops }, /* EVFILT_READ */
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{ &file_filtops }, /* EVFILT_WRITE */
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{ &null_filtops }, /* EVFILT_AIO */
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{ &file_filtops }, /* EVFILT_VNODE */
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{ &proc_filtops }, /* EVFILT_PROC */
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{ &sig_filtops }, /* EVFILT_SIGNAL */
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{ &timer_filtops }, /* EVFILT_TIMER */
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{ &null_filtops }, /* former EVFILT_NETDEV */
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{ &fs_filtops }, /* EVFILT_FS */
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{ &null_filtops }, /* EVFILT_LIO */
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{ &user_filtops }, /* EVFILT_USER */
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};
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/*
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* Simple redirection for all cdevsw style objects to call their fo_kqfilter
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* method.
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*/
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static int
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filt_fileattach(struct knote *kn)
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{
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return (fo_kqfilter(kn->kn_fp, kn));
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}
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/*ARGSUSED*/
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static int
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kqueue_kqfilter(struct file *fp, struct knote *kn)
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{
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struct kqueue *kq = kn->kn_fp->f_data;
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if (kn->kn_filter != EVFILT_READ)
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return (EINVAL);
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kn->kn_status |= KN_KQUEUE;
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kn->kn_fop = &kqread_filtops;
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knlist_add(&kq->kq_sel.si_note, kn, 0);
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return (0);
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}
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static void
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filt_kqdetach(struct knote *kn)
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{
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struct kqueue *kq = kn->kn_fp->f_data;
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knlist_remove(&kq->kq_sel.si_note, kn, 0);
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}
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/*ARGSUSED*/
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static int
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filt_kqueue(struct knote *kn, long hint)
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{
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struct kqueue *kq = kn->kn_fp->f_data;
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kn->kn_data = kq->kq_count;
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return (kn->kn_data > 0);
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}
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/* XXX - move to kern_proc.c? */
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static int
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filt_procattach(struct knote *kn)
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{
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struct proc *p;
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int immediate;
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int error;
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immediate = 0;
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p = pfind(kn->kn_id);
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if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) {
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p = zpfind(kn->kn_id);
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immediate = 1;
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} else if (p != NULL && (p->p_flag & P_WEXIT)) {
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immediate = 1;
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}
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if (p == NULL)
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return (ESRCH);
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if ((error = p_cansee(curthread, p))) {
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PROC_UNLOCK(p);
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return (error);
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}
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kn->kn_ptr.p_proc = p;
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kn->kn_flags |= EV_CLEAR; /* automatically set */
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/*
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* internal flag indicating registration done by kernel
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*/
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if (kn->kn_flags & EV_FLAG1) {
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kn->kn_data = kn->kn_sdata; /* ppid */
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kn->kn_fflags = NOTE_CHILD;
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kn->kn_flags &= ~EV_FLAG1;
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}
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if (immediate == 0)
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knlist_add(&p->p_klist, kn, 1);
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/*
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* Immediately activate any exit notes if the target process is a
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* zombie. This is necessary to handle the case where the target
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* process, e.g. a child, dies before the kevent is registered.
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*/
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if (immediate && filt_proc(kn, NOTE_EXIT))
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KNOTE_ACTIVATE(kn, 0);
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PROC_UNLOCK(p);
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return (0);
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}
|
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|
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/*
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* The knote may be attached to a different process, which may exit,
|
|
* leaving nothing for the knote to be attached to. So when the process
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* exits, the knote is marked as DETACHED and also flagged as ONESHOT so
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* it will be deleted when read out. However, as part of the knote deletion,
|
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* this routine is called, so a check is needed to avoid actually performing
|
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* a detach, because the original process does not exist any more.
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*/
|
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/* XXX - move to kern_proc.c? */
|
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static void
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filt_procdetach(struct knote *kn)
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{
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struct proc *p;
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p = kn->kn_ptr.p_proc;
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knlist_remove(&p->p_klist, kn, 0);
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kn->kn_ptr.p_proc = NULL;
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}
|
|
|
|
/* XXX - move to kern_proc.c? */
|
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static int
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filt_proc(struct knote *kn, long hint)
|
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{
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struct proc *p = kn->kn_ptr.p_proc;
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u_int event;
|
|
|
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/*
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* mask off extra data
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|
*/
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event = (u_int)hint & NOTE_PCTRLMASK;
|
|
|
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/*
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|
* if the user is interested in this event, record it.
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|
*/
|
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if (kn->kn_sfflags & event)
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kn->kn_fflags |= event;
|
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|
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/*
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|
* process is gone, so flag the event as finished.
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|
*/
|
|
if (event == NOTE_EXIT) {
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if (!(kn->kn_status & KN_DETACHED))
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|
knlist_remove_inevent(&p->p_klist, kn);
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kn->kn_flags |= (EV_EOF | EV_ONESHOT);
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kn->kn_data = p->p_xstat;
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kn->kn_ptr.p_proc = NULL;
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return (1);
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}
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|
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return (kn->kn_fflags != 0);
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}
|
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|
|
/*
|
|
* Called when the process forked. It mostly does the same as the
|
|
* knote(), activating all knotes registered to be activated when the
|
|
* process forked. Additionally, for each knote attached to the
|
|
* parent, check whether user wants to track the new process. If so
|
|
* attach a new knote to it, and immediately report an event with the
|
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* child's pid.
|
|
*/
|
|
void
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knote_fork(struct knlist *list, int pid)
|
|
{
|
|
struct kqueue *kq;
|
|
struct knote *kn;
|
|
struct kevent kev;
|
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int error;
|
|
|
|
if (list == NULL)
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return;
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list->kl_lock(list->kl_lockarg);
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|
|
|
SLIST_FOREACH(kn, &list->kl_list, kn_selnext) {
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if ((kn->kn_status & KN_INFLUX) == KN_INFLUX)
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continue;
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kq = kn->kn_kq;
|
|
KQ_LOCK(kq);
|
|
if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
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KQ_UNLOCK(kq);
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continue;
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}
|
|
|
|
/*
|
|
* The same as knote(), activate the event.
|
|
*/
|
|
if ((kn->kn_sfflags & NOTE_TRACK) == 0) {
|
|
kn->kn_status |= KN_HASKQLOCK;
|
|
if (kn->kn_fop->f_event(kn, NOTE_FORK | pid))
|
|
KNOTE_ACTIVATE(kn, 1);
|
|
kn->kn_status &= ~KN_HASKQLOCK;
|
|
KQ_UNLOCK(kq);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* The NOTE_TRACK case. In addition to the activation
|
|
* of the event, we need to register new event to
|
|
* track the child. Drop the locks in preparation for
|
|
* the call to kqueue_register().
|
|
*/
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
list->kl_unlock(list->kl_lockarg);
|
|
|
|
/*
|
|
* Activate existing knote and register a knote with
|
|
* new process.
|
|
*/
|
|
kev.ident = pid;
|
|
kev.filter = kn->kn_filter;
|
|
kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
|
|
kev.fflags = kn->kn_sfflags;
|
|
kev.data = kn->kn_id; /* parent */
|
|
kev.udata = kn->kn_kevent.udata;/* preserve udata */
|
|
error = kqueue_register(kq, &kev, NULL, 0);
|
|
if (kn->kn_fop->f_event(kn, NOTE_FORK | pid))
|
|
KNOTE_ACTIVATE(kn, 0);
|
|
if (error)
|
|
kn->kn_fflags |= NOTE_TRACKERR;
|
|
KQ_LOCK(kq);
|
|
kn->kn_status &= ~KN_INFLUX;
|
|
KQ_UNLOCK_FLUX(kq);
|
|
list->kl_lock(list->kl_lockarg);
|
|
}
|
|
list->kl_unlock(list->kl_lockarg);
|
|
}
|
|
|
|
/*
|
|
* XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the
|
|
* interval timer support code.
|
|
*/
|
|
static __inline sbintime_t
|
|
timer2sbintime(intptr_t data)
|
|
{
|
|
|
|
return (SBT_1MS * data);
|
|
}
|
|
|
|
static void
|
|
filt_timerexpire(void *knx)
|
|
{
|
|
struct callout *calloutp;
|
|
struct knote *kn;
|
|
|
|
kn = knx;
|
|
kn->kn_data++;
|
|
KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */
|
|
|
|
if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) {
|
|
calloutp = (struct callout *)kn->kn_hook;
|
|
callout_reset_sbt_on(calloutp,
|
|
timer2sbintime(kn->kn_sdata), 0 /* 1ms? */,
|
|
filt_timerexpire, kn, PCPU_GET(cpuid), 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* data contains amount of time to sleep, in milliseconds
|
|
*/
|
|
static int
|
|
filt_timerattach(struct knote *kn)
|
|
{
|
|
struct callout *calloutp;
|
|
unsigned int ncallouts;
|
|
|
|
ncallouts = atomic_load_explicit(&kq_ncallouts, memory_order_relaxed);
|
|
do {
|
|
if (ncallouts >= kq_calloutmax)
|
|
return (ENOMEM);
|
|
} while (!atomic_compare_exchange_weak_explicit(&kq_ncallouts,
|
|
&ncallouts, ncallouts + 1, memory_order_relaxed,
|
|
memory_order_relaxed));
|
|
|
|
kn->kn_flags |= EV_CLEAR; /* automatically set */
|
|
kn->kn_status &= ~KN_DETACHED; /* knlist_add usually sets it */
|
|
calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK);
|
|
callout_init(calloutp, CALLOUT_MPSAFE);
|
|
kn->kn_hook = calloutp;
|
|
callout_reset_sbt_on(calloutp,
|
|
timer2sbintime(kn->kn_sdata), 0 /* 1ms? */,
|
|
filt_timerexpire, kn, PCPU_GET(cpuid), 0);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
filt_timerdetach(struct knote *kn)
|
|
{
|
|
struct callout *calloutp;
|
|
unsigned int old;
|
|
|
|
calloutp = (struct callout *)kn->kn_hook;
|
|
callout_drain(calloutp);
|
|
free(calloutp, M_KQUEUE);
|
|
old = atomic_fetch_sub_explicit(&kq_ncallouts, 1, memory_order_relaxed);
|
|
KASSERT(old > 0, ("Number of callouts cannot become negative"));
|
|
kn->kn_status |= KN_DETACHED; /* knlist_remove usually clears it */
|
|
}
|
|
|
|
static int
|
|
filt_timer(struct knote *kn, long hint)
|
|
{
|
|
|
|
return (kn->kn_data != 0);
|
|
}
|
|
|
|
static int
|
|
filt_userattach(struct knote *kn)
|
|
{
|
|
|
|
/*
|
|
* EVFILT_USER knotes are not attached to anything in the kernel.
|
|
*/
|
|
kn->kn_hook = NULL;
|
|
if (kn->kn_fflags & NOTE_TRIGGER)
|
|
kn->kn_hookid = 1;
|
|
else
|
|
kn->kn_hookid = 0;
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
filt_userdetach(__unused struct knote *kn)
|
|
{
|
|
|
|
/*
|
|
* EVFILT_USER knotes are not attached to anything in the kernel.
|
|
*/
|
|
}
|
|
|
|
static int
|
|
filt_user(struct knote *kn, __unused long hint)
|
|
{
|
|
|
|
return (kn->kn_hookid);
|
|
}
|
|
|
|
static void
|
|
filt_usertouch(struct knote *kn, struct kevent *kev, u_long type)
|
|
{
|
|
u_int ffctrl;
|
|
|
|
switch (type) {
|
|
case EVENT_REGISTER:
|
|
if (kev->fflags & NOTE_TRIGGER)
|
|
kn->kn_hookid = 1;
|
|
|
|
ffctrl = kev->fflags & NOTE_FFCTRLMASK;
|
|
kev->fflags &= NOTE_FFLAGSMASK;
|
|
switch (ffctrl) {
|
|
case NOTE_FFNOP:
|
|
break;
|
|
|
|
case NOTE_FFAND:
|
|
kn->kn_sfflags &= kev->fflags;
|
|
break;
|
|
|
|
case NOTE_FFOR:
|
|
kn->kn_sfflags |= kev->fflags;
|
|
break;
|
|
|
|
case NOTE_FFCOPY:
|
|
kn->kn_sfflags = kev->fflags;
|
|
break;
|
|
|
|
default:
|
|
/* XXX Return error? */
|
|
break;
|
|
}
|
|
kn->kn_sdata = kev->data;
|
|
if (kev->flags & EV_CLEAR) {
|
|
kn->kn_hookid = 0;
|
|
kn->kn_data = 0;
|
|
kn->kn_fflags = 0;
|
|
}
|
|
break;
|
|
|
|
case EVENT_PROCESS:
|
|
*kev = kn->kn_kevent;
|
|
kev->fflags = kn->kn_sfflags;
|
|
kev->data = kn->kn_sdata;
|
|
if (kn->kn_flags & EV_CLEAR) {
|
|
kn->kn_hookid = 0;
|
|
kn->kn_data = 0;
|
|
kn->kn_fflags = 0;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
panic("filt_usertouch() - invalid type (%ld)", type);
|
|
break;
|
|
}
|
|
}
|
|
|
|
int
|
|
sys_kqueue(struct thread *td, struct kqueue_args *uap)
|
|
{
|
|
struct filedesc *fdp;
|
|
struct kqueue *kq;
|
|
struct file *fp;
|
|
int fd, error;
|
|
|
|
fdp = td->td_proc->p_fd;
|
|
error = falloc(td, &fp, &fd, 0);
|
|
if (error)
|
|
goto done2;
|
|
|
|
/* An extra reference on `fp' has been held for us by falloc(). */
|
|
kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO);
|
|
mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK);
|
|
TAILQ_INIT(&kq->kq_head);
|
|
kq->kq_fdp = fdp;
|
|
knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock);
|
|
TASK_INIT(&kq->kq_task, 0, kqueue_task, kq);
|
|
|
|
FILEDESC_XLOCK(fdp);
|
|
SLIST_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list);
|
|
FILEDESC_XUNLOCK(fdp);
|
|
|
|
finit(fp, FREAD | FWRITE, DTYPE_KQUEUE, kq, &kqueueops);
|
|
fdrop(fp, td);
|
|
|
|
td->td_retval[0] = fd;
|
|
done2:
|
|
return (error);
|
|
}
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct kevent_args {
|
|
int fd;
|
|
const struct kevent *changelist;
|
|
int nchanges;
|
|
struct kevent *eventlist;
|
|
int nevents;
|
|
const struct timespec *timeout;
|
|
};
|
|
#endif
|
|
int
|
|
sys_kevent(struct thread *td, struct kevent_args *uap)
|
|
{
|
|
struct timespec ts, *tsp;
|
|
struct kevent_copyops k_ops = { uap,
|
|
kevent_copyout,
|
|
kevent_copyin};
|
|
int error;
|
|
#ifdef KTRACE
|
|
struct uio ktruio;
|
|
struct iovec ktriov;
|
|
struct uio *ktruioin = NULL;
|
|
struct uio *ktruioout = NULL;
|
|
#endif
|
|
|
|
if (uap->timeout != NULL) {
|
|
error = copyin(uap->timeout, &ts, sizeof(ts));
|
|
if (error)
|
|
return (error);
|
|
tsp = &ts;
|
|
} else
|
|
tsp = NULL;
|
|
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(td, KTR_GENIO)) {
|
|
ktriov.iov_base = uap->changelist;
|
|
ktriov.iov_len = uap->nchanges * sizeof(struct kevent);
|
|
ktruio = (struct uio){ .uio_iov = &ktriov, .uio_iovcnt = 1,
|
|
.uio_segflg = UIO_USERSPACE, .uio_rw = UIO_READ,
|
|
.uio_td = td };
|
|
ktruioin = cloneuio(&ktruio);
|
|
ktriov.iov_base = uap->eventlist;
|
|
ktriov.iov_len = uap->nevents * sizeof(struct kevent);
|
|
ktruioout = cloneuio(&ktruio);
|
|
}
|
|
#endif
|
|
|
|
error = kern_kevent(td, uap->fd, uap->nchanges, uap->nevents,
|
|
&k_ops, tsp);
|
|
|
|
#ifdef KTRACE
|
|
if (ktruioin != NULL) {
|
|
ktruioin->uio_resid = uap->nchanges * sizeof(struct kevent);
|
|
ktrgenio(uap->fd, UIO_WRITE, ktruioin, 0);
|
|
ktruioout->uio_resid = td->td_retval[0] * sizeof(struct kevent);
|
|
ktrgenio(uap->fd, UIO_READ, ktruioout, error);
|
|
}
|
|
#endif
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Copy 'count' items into the destination list pointed to by uap->eventlist.
|
|
*/
|
|
static int
|
|
kevent_copyout(void *arg, struct kevent *kevp, int count)
|
|
{
|
|
struct kevent_args *uap;
|
|
int error;
|
|
|
|
KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count));
|
|
uap = (struct kevent_args *)arg;
|
|
|
|
error = copyout(kevp, uap->eventlist, count * sizeof *kevp);
|
|
if (error == 0)
|
|
uap->eventlist += count;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Copy 'count' items from the list pointed to by uap->changelist.
|
|
*/
|
|
static int
|
|
kevent_copyin(void *arg, struct kevent *kevp, int count)
|
|
{
|
|
struct kevent_args *uap;
|
|
int error;
|
|
|
|
KASSERT(count <= KQ_NEVENTS, ("count (%d) > KQ_NEVENTS", count));
|
|
uap = (struct kevent_args *)arg;
|
|
|
|
error = copyin(uap->changelist, kevp, count * sizeof *kevp);
|
|
if (error == 0)
|
|
uap->changelist += count;
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
kern_kevent(struct thread *td, int fd, int nchanges, int nevents,
|
|
struct kevent_copyops *k_ops, const struct timespec *timeout)
|
|
{
|
|
struct kevent keva[KQ_NEVENTS];
|
|
struct kevent *kevp, *changes;
|
|
struct kqueue *kq;
|
|
struct file *fp;
|
|
int i, n, nerrors, error;
|
|
|
|
if ((error = fget(td, fd, CAP_POST_EVENT, &fp)) != 0)
|
|
return (error);
|
|
if ((error = kqueue_acquire(fp, &kq)) != 0)
|
|
goto done_norel;
|
|
|
|
nerrors = 0;
|
|
|
|
while (nchanges > 0) {
|
|
n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges;
|
|
error = k_ops->k_copyin(k_ops->arg, keva, n);
|
|
if (error)
|
|
goto done;
|
|
changes = keva;
|
|
for (i = 0; i < n; i++) {
|
|
kevp = &changes[i];
|
|
if (!kevp->filter)
|
|
continue;
|
|
kevp->flags &= ~EV_SYSFLAGS;
|
|
error = kqueue_register(kq, kevp, td, 1);
|
|
if (error || (kevp->flags & EV_RECEIPT)) {
|
|
if (nevents != 0) {
|
|
kevp->flags = EV_ERROR;
|
|
kevp->data = error;
|
|
(void) k_ops->k_copyout(k_ops->arg,
|
|
kevp, 1);
|
|
nevents--;
|
|
nerrors++;
|
|
} else {
|
|
goto done;
|
|
}
|
|
}
|
|
}
|
|
nchanges -= n;
|
|
}
|
|
if (nerrors) {
|
|
td->td_retval[0] = nerrors;
|
|
error = 0;
|
|
goto done;
|
|
}
|
|
|
|
error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td);
|
|
done:
|
|
kqueue_release(kq, 0);
|
|
done_norel:
|
|
fdrop(fp, td);
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
kqueue_add_filteropts(int filt, struct filterops *filtops)
|
|
{
|
|
int error;
|
|
|
|
error = 0;
|
|
if (filt > 0 || filt + EVFILT_SYSCOUNT < 0) {
|
|
printf(
|
|
"trying to add a filterop that is out of range: %d is beyond %d\n",
|
|
~filt, EVFILT_SYSCOUNT);
|
|
return EINVAL;
|
|
}
|
|
mtx_lock(&filterops_lock);
|
|
if (sysfilt_ops[~filt].for_fop != &null_filtops &&
|
|
sysfilt_ops[~filt].for_fop != NULL)
|
|
error = EEXIST;
|
|
else {
|
|
sysfilt_ops[~filt].for_fop = filtops;
|
|
sysfilt_ops[~filt].for_refcnt = 0;
|
|
}
|
|
mtx_unlock(&filterops_lock);
|
|
|
|
return (error);
|
|
}
|
|
|
|
int
|
|
kqueue_del_filteropts(int filt)
|
|
{
|
|
int error;
|
|
|
|
error = 0;
|
|
if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
|
|
return EINVAL;
|
|
|
|
mtx_lock(&filterops_lock);
|
|
if (sysfilt_ops[~filt].for_fop == &null_filtops ||
|
|
sysfilt_ops[~filt].for_fop == NULL)
|
|
error = EINVAL;
|
|
else if (sysfilt_ops[~filt].for_refcnt != 0)
|
|
error = EBUSY;
|
|
else {
|
|
sysfilt_ops[~filt].for_fop = &null_filtops;
|
|
sysfilt_ops[~filt].for_refcnt = 0;
|
|
}
|
|
mtx_unlock(&filterops_lock);
|
|
|
|
return error;
|
|
}
|
|
|
|
static struct filterops *
|
|
kqueue_fo_find(int filt)
|
|
{
|
|
|
|
if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
|
|
return NULL;
|
|
|
|
mtx_lock(&filterops_lock);
|
|
sysfilt_ops[~filt].for_refcnt++;
|
|
if (sysfilt_ops[~filt].for_fop == NULL)
|
|
sysfilt_ops[~filt].for_fop = &null_filtops;
|
|
mtx_unlock(&filterops_lock);
|
|
|
|
return sysfilt_ops[~filt].for_fop;
|
|
}
|
|
|
|
static void
|
|
kqueue_fo_release(int filt)
|
|
{
|
|
|
|
if (filt > 0 || filt + EVFILT_SYSCOUNT < 0)
|
|
return;
|
|
|
|
mtx_lock(&filterops_lock);
|
|
KASSERT(sysfilt_ops[~filt].for_refcnt > 0,
|
|
("filter object refcount not valid on release"));
|
|
sysfilt_ops[~filt].for_refcnt--;
|
|
mtx_unlock(&filterops_lock);
|
|
}
|
|
|
|
/*
|
|
* A ref to kq (obtained via kqueue_acquire) must be held. waitok will
|
|
* influence if memory allocation should wait. Make sure it is 0 if you
|
|
* hold any mutexes.
|
|
*/
|
|
static int
|
|
kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int waitok)
|
|
{
|
|
struct filterops *fops;
|
|
struct file *fp;
|
|
struct knote *kn, *tkn;
|
|
int error, filt, event;
|
|
int haskqglobal;
|
|
|
|
fp = NULL;
|
|
kn = NULL;
|
|
error = 0;
|
|
haskqglobal = 0;
|
|
|
|
filt = kev->filter;
|
|
fops = kqueue_fo_find(filt);
|
|
if (fops == NULL)
|
|
return EINVAL;
|
|
|
|
tkn = knote_alloc(waitok); /* prevent waiting with locks */
|
|
|
|
findkn:
|
|
if (fops->f_isfd) {
|
|
KASSERT(td != NULL, ("td is NULL"));
|
|
error = fget(td, kev->ident, CAP_POLL_EVENT, &fp);
|
|
if (error)
|
|
goto done;
|
|
|
|
if ((kev->flags & EV_ADD) == EV_ADD && kqueue_expand(kq, fops,
|
|
kev->ident, 0) != 0) {
|
|
/* try again */
|
|
fdrop(fp, td);
|
|
fp = NULL;
|
|
error = kqueue_expand(kq, fops, kev->ident, waitok);
|
|
if (error)
|
|
goto done;
|
|
goto findkn;
|
|
}
|
|
|
|
if (fp->f_type == DTYPE_KQUEUE) {
|
|
/*
|
|
* if we add some inteligence about what we are doing,
|
|
* we should be able to support events on ourselves.
|
|
* We need to know when we are doing this to prevent
|
|
* getting both the knlist lock and the kq lock since
|
|
* they are the same thing.
|
|
*/
|
|
if (fp->f_data == kq) {
|
|
error = EINVAL;
|
|
goto done;
|
|
}
|
|
|
|
KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
|
|
}
|
|
|
|
KQ_LOCK(kq);
|
|
if (kev->ident < kq->kq_knlistsize) {
|
|
SLIST_FOREACH(kn, &kq->kq_knlist[kev->ident], kn_link)
|
|
if (kev->filter == kn->kn_filter)
|
|
break;
|
|
}
|
|
} else {
|
|
if ((kev->flags & EV_ADD) == EV_ADD)
|
|
kqueue_expand(kq, fops, kev->ident, waitok);
|
|
|
|
KQ_LOCK(kq);
|
|
if (kq->kq_knhashmask != 0) {
|
|
struct klist *list;
|
|
|
|
list = &kq->kq_knhash[
|
|
KN_HASH((u_long)kev->ident, kq->kq_knhashmask)];
|
|
SLIST_FOREACH(kn, list, kn_link)
|
|
if (kev->ident == kn->kn_id &&
|
|
kev->filter == kn->kn_filter)
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* knote is in the process of changing, wait for it to stablize. */
|
|
if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) {
|
|
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
|
|
kq->kq_state |= KQ_FLUXWAIT;
|
|
msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0);
|
|
if (fp != NULL) {
|
|
fdrop(fp, td);
|
|
fp = NULL;
|
|
}
|
|
goto findkn;
|
|
}
|
|
|
|
/*
|
|
* kn now contains the matching knote, or NULL if no match
|
|
*/
|
|
if (kn == NULL) {
|
|
if (kev->flags & EV_ADD) {
|
|
kn = tkn;
|
|
tkn = NULL;
|
|
if (kn == NULL) {
|
|
KQ_UNLOCK(kq);
|
|
error = ENOMEM;
|
|
goto done;
|
|
}
|
|
kn->kn_fp = fp;
|
|
kn->kn_kq = kq;
|
|
kn->kn_fop = fops;
|
|
/*
|
|
* apply reference counts to knote structure, and
|
|
* do not release it at the end of this routine.
|
|
*/
|
|
fops = NULL;
|
|
fp = NULL;
|
|
|
|
kn->kn_sfflags = kev->fflags;
|
|
kn->kn_sdata = kev->data;
|
|
kev->fflags = 0;
|
|
kev->data = 0;
|
|
kn->kn_kevent = *kev;
|
|
kn->kn_kevent.flags &= ~(EV_ADD | EV_DELETE |
|
|
EV_ENABLE | EV_DISABLE);
|
|
kn->kn_status = KN_INFLUX|KN_DETACHED;
|
|
|
|
error = knote_attach(kn, kq);
|
|
KQ_UNLOCK(kq);
|
|
if (error != 0) {
|
|
tkn = kn;
|
|
goto done;
|
|
}
|
|
|
|
if ((error = kn->kn_fop->f_attach(kn)) != 0) {
|
|
knote_drop(kn, td);
|
|
goto done;
|
|
}
|
|
KN_LIST_LOCK(kn);
|
|
goto done_ev_add;
|
|
} else {
|
|
/* No matching knote and the EV_ADD flag is not set. */
|
|
KQ_UNLOCK(kq);
|
|
error = ENOENT;
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
if (kev->flags & EV_DELETE) {
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
if (!(kn->kn_status & KN_DETACHED))
|
|
kn->kn_fop->f_detach(kn);
|
|
knote_drop(kn, td);
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* The user may change some filter values after the initial EV_ADD,
|
|
* but doing so will not reset any filter which has already been
|
|
* triggered.
|
|
*/
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
KN_LIST_LOCK(kn);
|
|
kn->kn_kevent.udata = kev->udata;
|
|
if (!fops->f_isfd && fops->f_touch != NULL) {
|
|
fops->f_touch(kn, kev, EVENT_REGISTER);
|
|
} else {
|
|
kn->kn_sfflags = kev->fflags;
|
|
kn->kn_sdata = kev->data;
|
|
}
|
|
|
|
/*
|
|
* We can get here with kn->kn_knlist == NULL. This can happen when
|
|
* the initial attach event decides that the event is "completed"
|
|
* already. i.e. filt_procattach is called on a zombie process. It
|
|
* will call filt_proc which will remove it from the list, and NULL
|
|
* kn_knlist.
|
|
*/
|
|
done_ev_add:
|
|
event = kn->kn_fop->f_event(kn, 0);
|
|
KQ_LOCK(kq);
|
|
if (event)
|
|
KNOTE_ACTIVATE(kn, 1);
|
|
kn->kn_status &= ~KN_INFLUX;
|
|
KN_LIST_UNLOCK(kn);
|
|
|
|
if ((kev->flags & EV_DISABLE) &&
|
|
((kn->kn_status & KN_DISABLED) == 0)) {
|
|
kn->kn_status |= KN_DISABLED;
|
|
}
|
|
|
|
if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
|
|
kn->kn_status &= ~KN_DISABLED;
|
|
if ((kn->kn_status & KN_ACTIVE) &&
|
|
((kn->kn_status & KN_QUEUED) == 0))
|
|
knote_enqueue(kn);
|
|
}
|
|
KQ_UNLOCK_FLUX(kq);
|
|
|
|
done:
|
|
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
|
|
if (fp != NULL)
|
|
fdrop(fp, td);
|
|
if (tkn != NULL)
|
|
knote_free(tkn);
|
|
if (fops != NULL)
|
|
kqueue_fo_release(filt);
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
kqueue_acquire(struct file *fp, struct kqueue **kqp)
|
|
{
|
|
int error;
|
|
struct kqueue *kq;
|
|
|
|
error = 0;
|
|
|
|
kq = fp->f_data;
|
|
if (fp->f_type != DTYPE_KQUEUE || kq == NULL)
|
|
return (EBADF);
|
|
*kqp = kq;
|
|
KQ_LOCK(kq);
|
|
if ((kq->kq_state & KQ_CLOSING) == KQ_CLOSING) {
|
|
KQ_UNLOCK(kq);
|
|
return (EBADF);
|
|
}
|
|
kq->kq_refcnt++;
|
|
KQ_UNLOCK(kq);
|
|
|
|
return error;
|
|
}
|
|
|
|
static void
|
|
kqueue_release(struct kqueue *kq, int locked)
|
|
{
|
|
if (locked)
|
|
KQ_OWNED(kq);
|
|
else
|
|
KQ_LOCK(kq);
|
|
kq->kq_refcnt--;
|
|
if (kq->kq_refcnt == 1)
|
|
wakeup(&kq->kq_refcnt);
|
|
if (!locked)
|
|
KQ_UNLOCK(kq);
|
|
}
|
|
|
|
static void
|
|
kqueue_schedtask(struct kqueue *kq)
|
|
{
|
|
|
|
KQ_OWNED(kq);
|
|
KASSERT(((kq->kq_state & KQ_TASKDRAIN) != KQ_TASKDRAIN),
|
|
("scheduling kqueue task while draining"));
|
|
|
|
if ((kq->kq_state & KQ_TASKSCHED) != KQ_TASKSCHED) {
|
|
taskqueue_enqueue(taskqueue_kqueue, &kq->kq_task);
|
|
kq->kq_state |= KQ_TASKSCHED;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Expand the kq to make sure we have storage for fops/ident pair.
|
|
*
|
|
* Return 0 on success (or no work necessary), return errno on failure.
|
|
*
|
|
* Not calling hashinit w/ waitok (proper malloc flag) should be safe.
|
|
* If kqueue_register is called from a non-fd context, there usually/should
|
|
* be no locks held.
|
|
*/
|
|
static int
|
|
kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
|
|
int waitok)
|
|
{
|
|
struct klist *list, *tmp_knhash, *to_free;
|
|
u_long tmp_knhashmask;
|
|
int size;
|
|
int fd;
|
|
int mflag = waitok ? M_WAITOK : M_NOWAIT;
|
|
|
|
KQ_NOTOWNED(kq);
|
|
|
|
to_free = NULL;
|
|
if (fops->f_isfd) {
|
|
fd = ident;
|
|
if (kq->kq_knlistsize <= fd) {
|
|
size = kq->kq_knlistsize;
|
|
while (size <= fd)
|
|
size += KQEXTENT;
|
|
list = malloc(size * sizeof(*list), M_KQUEUE, mflag);
|
|
if (list == NULL)
|
|
return ENOMEM;
|
|
KQ_LOCK(kq);
|
|
if (kq->kq_knlistsize > fd) {
|
|
to_free = list;
|
|
list = NULL;
|
|
} else {
|
|
if (kq->kq_knlist != NULL) {
|
|
bcopy(kq->kq_knlist, list,
|
|
kq->kq_knlistsize * sizeof(*list));
|
|
to_free = kq->kq_knlist;
|
|
kq->kq_knlist = NULL;
|
|
}
|
|
bzero((caddr_t)list +
|
|
kq->kq_knlistsize * sizeof(*list),
|
|
(size - kq->kq_knlistsize) * sizeof(*list));
|
|
kq->kq_knlistsize = size;
|
|
kq->kq_knlist = list;
|
|
}
|
|
KQ_UNLOCK(kq);
|
|
}
|
|
} else {
|
|
if (kq->kq_knhashmask == 0) {
|
|
tmp_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
|
|
&tmp_knhashmask);
|
|
if (tmp_knhash == NULL)
|
|
return ENOMEM;
|
|
KQ_LOCK(kq);
|
|
if (kq->kq_knhashmask == 0) {
|
|
kq->kq_knhash = tmp_knhash;
|
|
kq->kq_knhashmask = tmp_knhashmask;
|
|
} else {
|
|
to_free = tmp_knhash;
|
|
}
|
|
KQ_UNLOCK(kq);
|
|
}
|
|
}
|
|
free(to_free, M_KQUEUE);
|
|
|
|
KQ_NOTOWNED(kq);
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
kqueue_task(void *arg, int pending)
|
|
{
|
|
struct kqueue *kq;
|
|
int haskqglobal;
|
|
|
|
haskqglobal = 0;
|
|
kq = arg;
|
|
|
|
KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
|
|
KQ_LOCK(kq);
|
|
|
|
KNOTE_LOCKED(&kq->kq_sel.si_note, 0);
|
|
|
|
kq->kq_state &= ~KQ_TASKSCHED;
|
|
if ((kq->kq_state & KQ_TASKDRAIN) == KQ_TASKDRAIN) {
|
|
wakeup(&kq->kq_state);
|
|
}
|
|
KQ_UNLOCK(kq);
|
|
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
|
|
}
|
|
|
|
/*
|
|
* Scan, update kn_data (if not ONESHOT), and copyout triggered events.
|
|
* We treat KN_MARKER knotes as if they are INFLUX.
|
|
*/
|
|
static int
|
|
kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops,
|
|
const struct timespec *tsp, struct kevent *keva, struct thread *td)
|
|
{
|
|
struct kevent *kevp;
|
|
struct knote *kn, *marker;
|
|
sbintime_t asbt, rsbt;
|
|
int count, error, haskqglobal, influx, nkev, touch;
|
|
|
|
count = maxevents;
|
|
nkev = 0;
|
|
error = 0;
|
|
haskqglobal = 0;
|
|
|
|
if (maxevents == 0)
|
|
goto done_nl;
|
|
|
|
rsbt = 0;
|
|
if (tsp != NULL) {
|
|
if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 ||
|
|
tsp->tv_nsec >= 1000000000) {
|
|
error = EINVAL;
|
|
goto done_nl;
|
|
}
|
|
if (timespecisset(tsp)) {
|
|
if (tsp->tv_sec <= INT32_MAX) {
|
|
rsbt = tstosbt(*tsp);
|
|
if (TIMESEL(&asbt, rsbt))
|
|
asbt += tc_tick_sbt;
|
|
if (asbt <= INT64_MAX - rsbt)
|
|
asbt += rsbt;
|
|
else
|
|
asbt = 0;
|
|
rsbt >>= tc_precexp;
|
|
} else
|
|
asbt = 0;
|
|
} else
|
|
asbt = -1;
|
|
} else
|
|
asbt = 0;
|
|
marker = knote_alloc(1);
|
|
if (marker == NULL) {
|
|
error = ENOMEM;
|
|
goto done_nl;
|
|
}
|
|
marker->kn_status = KN_MARKER;
|
|
KQ_LOCK(kq);
|
|
|
|
retry:
|
|
kevp = keva;
|
|
if (kq->kq_count == 0) {
|
|
if (asbt == -1) {
|
|
error = EWOULDBLOCK;
|
|
} else {
|
|
kq->kq_state |= KQ_SLEEP;
|
|
error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH,
|
|
"kqread", asbt, rsbt, C_ABSOLUTE);
|
|
}
|
|
if (error == 0)
|
|
goto retry;
|
|
/* don't restart after signals... */
|
|
if (error == ERESTART)
|
|
error = EINTR;
|
|
else if (error == EWOULDBLOCK)
|
|
error = 0;
|
|
goto done;
|
|
}
|
|
|
|
TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe);
|
|
influx = 0;
|
|
while (count) {
|
|
KQ_OWNED(kq);
|
|
kn = TAILQ_FIRST(&kq->kq_head);
|
|
|
|
if ((kn->kn_status == KN_MARKER && kn != marker) ||
|
|
(kn->kn_status & KN_INFLUX) == KN_INFLUX) {
|
|
if (influx) {
|
|
influx = 0;
|
|
KQ_FLUX_WAKEUP(kq);
|
|
}
|
|
kq->kq_state |= KQ_FLUXWAIT;
|
|
error = msleep(kq, &kq->kq_lock, PSOCK,
|
|
"kqflxwt", 0);
|
|
continue;
|
|
}
|
|
|
|
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
|
|
if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) {
|
|
kn->kn_status &= ~KN_QUEUED;
|
|
kq->kq_count--;
|
|
continue;
|
|
}
|
|
if (kn == marker) {
|
|
KQ_FLUX_WAKEUP(kq);
|
|
if (count == maxevents)
|
|
goto retry;
|
|
goto done;
|
|
}
|
|
KASSERT((kn->kn_status & KN_INFLUX) == 0,
|
|
("KN_INFLUX set when not suppose to be"));
|
|
|
|
if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) {
|
|
kn->kn_status &= ~KN_QUEUED;
|
|
kn->kn_status |= KN_INFLUX;
|
|
kq->kq_count--;
|
|
KQ_UNLOCK(kq);
|
|
/*
|
|
* We don't need to lock the list since we've marked
|
|
* it _INFLUX.
|
|
*/
|
|
*kevp = kn->kn_kevent;
|
|
if (!(kn->kn_status & KN_DETACHED))
|
|
kn->kn_fop->f_detach(kn);
|
|
knote_drop(kn, td);
|
|
KQ_LOCK(kq);
|
|
kn = NULL;
|
|
} else {
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
if ((kn->kn_status & KN_KQUEUE) == KN_KQUEUE)
|
|
KQ_GLOBAL_LOCK(&kq_global, haskqglobal);
|
|
KN_LIST_LOCK(kn);
|
|
if (kn->kn_fop->f_event(kn, 0) == 0) {
|
|
KQ_LOCK(kq);
|
|
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
|
|
kn->kn_status &=
|
|
~(KN_QUEUED | KN_ACTIVE | KN_INFLUX);
|
|
kq->kq_count--;
|
|
KN_LIST_UNLOCK(kn);
|
|
influx = 1;
|
|
continue;
|
|
}
|
|
touch = (!kn->kn_fop->f_isfd &&
|
|
kn->kn_fop->f_touch != NULL);
|
|
if (touch)
|
|
kn->kn_fop->f_touch(kn, kevp, EVENT_PROCESS);
|
|
else
|
|
*kevp = kn->kn_kevent;
|
|
KQ_LOCK(kq);
|
|
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
|
|
if (kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) {
|
|
/*
|
|
* Manually clear knotes who weren't
|
|
* 'touch'ed.
|
|
*/
|
|
if (touch == 0 && kn->kn_flags & EV_CLEAR) {
|
|
kn->kn_data = 0;
|
|
kn->kn_fflags = 0;
|
|
}
|
|
if (kn->kn_flags & EV_DISPATCH)
|
|
kn->kn_status |= KN_DISABLED;
|
|
kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
|
|
kq->kq_count--;
|
|
} else
|
|
TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
|
|
|
|
kn->kn_status &= ~(KN_INFLUX);
|
|
KN_LIST_UNLOCK(kn);
|
|
influx = 1;
|
|
}
|
|
|
|
/* we are returning a copy to the user */
|
|
kevp++;
|
|
nkev++;
|
|
count--;
|
|
|
|
if (nkev == KQ_NEVENTS) {
|
|
influx = 0;
|
|
KQ_UNLOCK_FLUX(kq);
|
|
error = k_ops->k_copyout(k_ops->arg, keva, nkev);
|
|
nkev = 0;
|
|
kevp = keva;
|
|
KQ_LOCK(kq);
|
|
if (error)
|
|
break;
|
|
}
|
|
}
|
|
TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe);
|
|
done:
|
|
KQ_OWNED(kq);
|
|
KQ_UNLOCK_FLUX(kq);
|
|
knote_free(marker);
|
|
done_nl:
|
|
KQ_NOTOWNED(kq);
|
|
if (nkev != 0)
|
|
error = k_ops->k_copyout(k_ops->arg, keva, nkev);
|
|
td->td_retval[0] = maxevents - count;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* XXX
|
|
* This could be expanded to call kqueue_scan, if desired.
|
|
*/
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
|
|
int flags, struct thread *td)
|
|
{
|
|
return (ENXIO);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
|
|
int flags, struct thread *td)
|
|
{
|
|
return (ENXIO);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_truncate(struct file *fp, off_t length, struct ucred *active_cred,
|
|
struct thread *td)
|
|
{
|
|
|
|
return (EINVAL);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_ioctl(struct file *fp, u_long cmd, void *data,
|
|
struct ucred *active_cred, struct thread *td)
|
|
{
|
|
/*
|
|
* Enabling sigio causes two major problems:
|
|
* 1) infinite recursion:
|
|
* Synopsys: kevent is being used to track signals and have FIOASYNC
|
|
* set. On receipt of a signal this will cause a kqueue to recurse
|
|
* into itself over and over. Sending the sigio causes the kqueue
|
|
* to become ready, which in turn posts sigio again, forever.
|
|
* Solution: this can be solved by setting a flag in the kqueue that
|
|
* we have a SIGIO in progress.
|
|
* 2) locking problems:
|
|
* Synopsys: Kqueue is a leaf subsystem, but adding signalling puts
|
|
* us above the proc and pgrp locks.
|
|
* Solution: Post a signal using an async mechanism, being sure to
|
|
* record a generation count in the delivery so that we do not deliver
|
|
* a signal to the wrong process.
|
|
*
|
|
* Note, these two mechanisms are somewhat mutually exclusive!
|
|
*/
|
|
#if 0
|
|
struct kqueue *kq;
|
|
|
|
kq = fp->f_data;
|
|
switch (cmd) {
|
|
case FIOASYNC:
|
|
if (*(int *)data) {
|
|
kq->kq_state |= KQ_ASYNC;
|
|
} else {
|
|
kq->kq_state &= ~KQ_ASYNC;
|
|
}
|
|
return (0);
|
|
|
|
case FIOSETOWN:
|
|
return (fsetown(*(int *)data, &kq->kq_sigio));
|
|
|
|
case FIOGETOWN:
|
|
*(int *)data = fgetown(&kq->kq_sigio);
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
return (ENOTTY);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_poll(struct file *fp, int events, struct ucred *active_cred,
|
|
struct thread *td)
|
|
{
|
|
struct kqueue *kq;
|
|
int revents = 0;
|
|
int error;
|
|
|
|
if ((error = kqueue_acquire(fp, &kq)))
|
|
return POLLERR;
|
|
|
|
KQ_LOCK(kq);
|
|
if (events & (POLLIN | POLLRDNORM)) {
|
|
if (kq->kq_count) {
|
|
revents |= events & (POLLIN | POLLRDNORM);
|
|
} else {
|
|
selrecord(td, &kq->kq_sel);
|
|
if (SEL_WAITING(&kq->kq_sel))
|
|
kq->kq_state |= KQ_SEL;
|
|
}
|
|
}
|
|
kqueue_release(kq, 1);
|
|
KQ_UNLOCK(kq);
|
|
return (revents);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
|
|
struct thread *td)
|
|
{
|
|
|
|
bzero((void *)st, sizeof *st);
|
|
/*
|
|
* We no longer return kq_count because the unlocked value is useless.
|
|
* If you spent all this time getting the count, why not spend your
|
|
* syscall better by calling kevent?
|
|
*
|
|
* XXX - This is needed for libc_r.
|
|
*/
|
|
st->st_mode = S_IFIFO;
|
|
return (0);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
kqueue_close(struct file *fp, struct thread *td)
|
|
{
|
|
struct kqueue *kq = fp->f_data;
|
|
struct filedesc *fdp;
|
|
struct knote *kn;
|
|
int i;
|
|
int error;
|
|
|
|
if ((error = kqueue_acquire(fp, &kq)))
|
|
return error;
|
|
|
|
KQ_LOCK(kq);
|
|
|
|
KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING,
|
|
("kqueue already closing"));
|
|
kq->kq_state |= KQ_CLOSING;
|
|
if (kq->kq_refcnt > 1)
|
|
msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0);
|
|
|
|
KASSERT(kq->kq_refcnt == 1, ("other refs are out there!"));
|
|
fdp = kq->kq_fdp;
|
|
|
|
KASSERT(knlist_empty(&kq->kq_sel.si_note),
|
|
("kqueue's knlist not empty"));
|
|
|
|
for (i = 0; i < kq->kq_knlistsize; i++) {
|
|
while ((kn = SLIST_FIRST(&kq->kq_knlist[i])) != NULL) {
|
|
if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
|
|
kq->kq_state |= KQ_FLUXWAIT;
|
|
msleep(kq, &kq->kq_lock, PSOCK, "kqclo1", 0);
|
|
continue;
|
|
}
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
if (!(kn->kn_status & KN_DETACHED))
|
|
kn->kn_fop->f_detach(kn);
|
|
knote_drop(kn, td);
|
|
KQ_LOCK(kq);
|
|
}
|
|
}
|
|
if (kq->kq_knhashmask != 0) {
|
|
for (i = 0; i <= kq->kq_knhashmask; i++) {
|
|
while ((kn = SLIST_FIRST(&kq->kq_knhash[i])) != NULL) {
|
|
if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
|
|
kq->kq_state |= KQ_FLUXWAIT;
|
|
msleep(kq, &kq->kq_lock, PSOCK,
|
|
"kqclo2", 0);
|
|
continue;
|
|
}
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
if (!(kn->kn_status & KN_DETACHED))
|
|
kn->kn_fop->f_detach(kn);
|
|
knote_drop(kn, td);
|
|
KQ_LOCK(kq);
|
|
}
|
|
}
|
|
}
|
|
|
|
if ((kq->kq_state & KQ_TASKSCHED) == KQ_TASKSCHED) {
|
|
kq->kq_state |= KQ_TASKDRAIN;
|
|
msleep(&kq->kq_state, &kq->kq_lock, PSOCK, "kqtqdr", 0);
|
|
}
|
|
|
|
if ((kq->kq_state & KQ_SEL) == KQ_SEL) {
|
|
selwakeuppri(&kq->kq_sel, PSOCK);
|
|
if (!SEL_WAITING(&kq->kq_sel))
|
|
kq->kq_state &= ~KQ_SEL;
|
|
}
|
|
|
|
KQ_UNLOCK(kq);
|
|
|
|
FILEDESC_XLOCK(fdp);
|
|
SLIST_REMOVE(&fdp->fd_kqlist, kq, kqueue, kq_list);
|
|
FILEDESC_XUNLOCK(fdp);
|
|
|
|
seldrain(&kq->kq_sel);
|
|
knlist_destroy(&kq->kq_sel.si_note);
|
|
mtx_destroy(&kq->kq_lock);
|
|
kq->kq_fdp = NULL;
|
|
|
|
if (kq->kq_knhash != NULL)
|
|
free(kq->kq_knhash, M_KQUEUE);
|
|
if (kq->kq_knlist != NULL)
|
|
free(kq->kq_knlist, M_KQUEUE);
|
|
|
|
funsetown(&kq->kq_sigio);
|
|
free(kq, M_KQUEUE);
|
|
fp->f_data = NULL;
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
kqueue_wakeup(struct kqueue *kq)
|
|
{
|
|
KQ_OWNED(kq);
|
|
|
|
if ((kq->kq_state & KQ_SLEEP) == KQ_SLEEP) {
|
|
kq->kq_state &= ~KQ_SLEEP;
|
|
wakeup(kq);
|
|
}
|
|
if ((kq->kq_state & KQ_SEL) == KQ_SEL) {
|
|
selwakeuppri(&kq->kq_sel, PSOCK);
|
|
if (!SEL_WAITING(&kq->kq_sel))
|
|
kq->kq_state &= ~KQ_SEL;
|
|
}
|
|
if (!knlist_empty(&kq->kq_sel.si_note))
|
|
kqueue_schedtask(kq);
|
|
if ((kq->kq_state & KQ_ASYNC) == KQ_ASYNC) {
|
|
pgsigio(&kq->kq_sigio, SIGIO, 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Walk down a list of knotes, activating them if their event has triggered.
|
|
*
|
|
* There is a possibility to optimize in the case of one kq watching another.
|
|
* Instead of scheduling a task to wake it up, you could pass enough state
|
|
* down the chain to make up the parent kqueue. Make this code functional
|
|
* first.
|
|
*/
|
|
void
|
|
knote(struct knlist *list, long hint, int lockflags)
|
|
{
|
|
struct kqueue *kq;
|
|
struct knote *kn;
|
|
int error;
|
|
|
|
if (list == NULL)
|
|
return;
|
|
|
|
KNL_ASSERT_LOCK(list, lockflags & KNF_LISTLOCKED);
|
|
|
|
if ((lockflags & KNF_LISTLOCKED) == 0)
|
|
list->kl_lock(list->kl_lockarg);
|
|
|
|
/*
|
|
* If we unlock the list lock (and set KN_INFLUX), we can eliminate
|
|
* the kqueue scheduling, but this will introduce four
|
|
* lock/unlock's for each knote to test. If we do, continue to use
|
|
* SLIST_FOREACH, SLIST_FOREACH_SAFE is not safe in our case, it is
|
|
* only safe if you want to remove the current item, which we are
|
|
* not doing.
|
|
*/
|
|
SLIST_FOREACH(kn, &list->kl_list, kn_selnext) {
|
|
kq = kn->kn_kq;
|
|
if ((kn->kn_status & KN_INFLUX) != KN_INFLUX) {
|
|
KQ_LOCK(kq);
|
|
if ((kn->kn_status & KN_INFLUX) == KN_INFLUX) {
|
|
KQ_UNLOCK(kq);
|
|
} else if ((lockflags & KNF_NOKQLOCK) != 0) {
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
error = kn->kn_fop->f_event(kn, hint);
|
|
KQ_LOCK(kq);
|
|
kn->kn_status &= ~KN_INFLUX;
|
|
if (error)
|
|
KNOTE_ACTIVATE(kn, 1);
|
|
KQ_UNLOCK_FLUX(kq);
|
|
} else {
|
|
kn->kn_status |= KN_HASKQLOCK;
|
|
if (kn->kn_fop->f_event(kn, hint))
|
|
KNOTE_ACTIVATE(kn, 1);
|
|
kn->kn_status &= ~KN_HASKQLOCK;
|
|
KQ_UNLOCK(kq);
|
|
}
|
|
}
|
|
kq = NULL;
|
|
}
|
|
if ((lockflags & KNF_LISTLOCKED) == 0)
|
|
list->kl_unlock(list->kl_lockarg);
|
|
}
|
|
|
|
/*
|
|
* add a knote to a knlist
|
|
*/
|
|
void
|
|
knlist_add(struct knlist *knl, struct knote *kn, int islocked)
|
|
{
|
|
KNL_ASSERT_LOCK(knl, islocked);
|
|
KQ_NOTOWNED(kn->kn_kq);
|
|
KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) ==
|
|
(KN_INFLUX|KN_DETACHED), ("knote not KN_INFLUX and KN_DETACHED"));
|
|
if (!islocked)
|
|
knl->kl_lock(knl->kl_lockarg);
|
|
SLIST_INSERT_HEAD(&knl->kl_list, kn, kn_selnext);
|
|
if (!islocked)
|
|
knl->kl_unlock(knl->kl_lockarg);
|
|
KQ_LOCK(kn->kn_kq);
|
|
kn->kn_knlist = knl;
|
|
kn->kn_status &= ~KN_DETACHED;
|
|
KQ_UNLOCK(kn->kn_kq);
|
|
}
|
|
|
|
static void
|
|
knlist_remove_kq(struct knlist *knl, struct knote *kn, int knlislocked, int kqislocked)
|
|
{
|
|
KASSERT(!(!!kqislocked && !knlislocked), ("kq locked w/o knl locked"));
|
|
KNL_ASSERT_LOCK(knl, knlislocked);
|
|
mtx_assert(&kn->kn_kq->kq_lock, kqislocked ? MA_OWNED : MA_NOTOWNED);
|
|
if (!kqislocked)
|
|
KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX,
|
|
("knlist_remove called w/o knote being KN_INFLUX or already removed"));
|
|
if (!knlislocked)
|
|
knl->kl_lock(knl->kl_lockarg);
|
|
SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext);
|
|
kn->kn_knlist = NULL;
|
|
if (!knlislocked)
|
|
knl->kl_unlock(knl->kl_lockarg);
|
|
if (!kqislocked)
|
|
KQ_LOCK(kn->kn_kq);
|
|
kn->kn_status |= KN_DETACHED;
|
|
if (!kqislocked)
|
|
KQ_UNLOCK(kn->kn_kq);
|
|
}
|
|
|
|
/*
|
|
* remove all knotes from a specified klist
|
|
*/
|
|
void
|
|
knlist_remove(struct knlist *knl, struct knote *kn, int islocked)
|
|
{
|
|
|
|
knlist_remove_kq(knl, kn, islocked, 0);
|
|
}
|
|
|
|
/*
|
|
* remove knote from a specified klist while in f_event handler.
|
|
*/
|
|
void
|
|
knlist_remove_inevent(struct knlist *knl, struct knote *kn)
|
|
{
|
|
|
|
knlist_remove_kq(knl, kn, 1,
|
|
(kn->kn_status & KN_HASKQLOCK) == KN_HASKQLOCK);
|
|
}
|
|
|
|
int
|
|
knlist_empty(struct knlist *knl)
|
|
{
|
|
|
|
KNL_ASSERT_LOCKED(knl);
|
|
return SLIST_EMPTY(&knl->kl_list);
|
|
}
|
|
|
|
static struct mtx knlist_lock;
|
|
MTX_SYSINIT(knlist_lock, &knlist_lock, "knlist lock for lockless objects",
|
|
MTX_DEF);
|
|
static void knlist_mtx_lock(void *arg);
|
|
static void knlist_mtx_unlock(void *arg);
|
|
|
|
static void
|
|
knlist_mtx_lock(void *arg)
|
|
{
|
|
|
|
mtx_lock((struct mtx *)arg);
|
|
}
|
|
|
|
static void
|
|
knlist_mtx_unlock(void *arg)
|
|
{
|
|
|
|
mtx_unlock((struct mtx *)arg);
|
|
}
|
|
|
|
static void
|
|
knlist_mtx_assert_locked(void *arg)
|
|
{
|
|
|
|
mtx_assert((struct mtx *)arg, MA_OWNED);
|
|
}
|
|
|
|
static void
|
|
knlist_mtx_assert_unlocked(void *arg)
|
|
{
|
|
|
|
mtx_assert((struct mtx *)arg, MA_NOTOWNED);
|
|
}
|
|
|
|
static void
|
|
knlist_rw_rlock(void *arg)
|
|
{
|
|
|
|
rw_rlock((struct rwlock *)arg);
|
|
}
|
|
|
|
static void
|
|
knlist_rw_runlock(void *arg)
|
|
{
|
|
|
|
rw_runlock((struct rwlock *)arg);
|
|
}
|
|
|
|
static void
|
|
knlist_rw_assert_locked(void *arg)
|
|
{
|
|
|
|
rw_assert((struct rwlock *)arg, RA_LOCKED);
|
|
}
|
|
|
|
static void
|
|
knlist_rw_assert_unlocked(void *arg)
|
|
{
|
|
|
|
rw_assert((struct rwlock *)arg, RA_UNLOCKED);
|
|
}
|
|
|
|
void
|
|
knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
|
|
void (*kl_unlock)(void *),
|
|
void (*kl_assert_locked)(void *), void (*kl_assert_unlocked)(void *))
|
|
{
|
|
|
|
if (lock == NULL)
|
|
knl->kl_lockarg = &knlist_lock;
|
|
else
|
|
knl->kl_lockarg = lock;
|
|
|
|
if (kl_lock == NULL)
|
|
knl->kl_lock = knlist_mtx_lock;
|
|
else
|
|
knl->kl_lock = kl_lock;
|
|
if (kl_unlock == NULL)
|
|
knl->kl_unlock = knlist_mtx_unlock;
|
|
else
|
|
knl->kl_unlock = kl_unlock;
|
|
if (kl_assert_locked == NULL)
|
|
knl->kl_assert_locked = knlist_mtx_assert_locked;
|
|
else
|
|
knl->kl_assert_locked = kl_assert_locked;
|
|
if (kl_assert_unlocked == NULL)
|
|
knl->kl_assert_unlocked = knlist_mtx_assert_unlocked;
|
|
else
|
|
knl->kl_assert_unlocked = kl_assert_unlocked;
|
|
|
|
SLIST_INIT(&knl->kl_list);
|
|
}
|
|
|
|
void
|
|
knlist_init_mtx(struct knlist *knl, struct mtx *lock)
|
|
{
|
|
|
|
knlist_init(knl, lock, NULL, NULL, NULL, NULL);
|
|
}
|
|
|
|
void
|
|
knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock)
|
|
{
|
|
|
|
knlist_init(knl, lock, knlist_rw_rlock, knlist_rw_runlock,
|
|
knlist_rw_assert_locked, knlist_rw_assert_unlocked);
|
|
}
|
|
|
|
void
|
|
knlist_destroy(struct knlist *knl)
|
|
{
|
|
|
|
#ifdef INVARIANTS
|
|
/*
|
|
* if we run across this error, we need to find the offending
|
|
* driver and have it call knlist_clear.
|
|
*/
|
|
if (!SLIST_EMPTY(&knl->kl_list))
|
|
printf("WARNING: destroying knlist w/ knotes on it!\n");
|
|
#endif
|
|
|
|
knl->kl_lockarg = knl->kl_lock = knl->kl_unlock = NULL;
|
|
SLIST_INIT(&knl->kl_list);
|
|
}
|
|
|
|
/*
|
|
* Even if we are locked, we may need to drop the lock to allow any influx
|
|
* knotes time to "settle".
|
|
*/
|
|
void
|
|
knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn)
|
|
{
|
|
struct knote *kn, *kn2;
|
|
struct kqueue *kq;
|
|
|
|
if (islocked)
|
|
KNL_ASSERT_LOCKED(knl);
|
|
else {
|
|
KNL_ASSERT_UNLOCKED(knl);
|
|
again: /* need to reacquire lock since we have dropped it */
|
|
knl->kl_lock(knl->kl_lockarg);
|
|
}
|
|
|
|
SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) {
|
|
kq = kn->kn_kq;
|
|
KQ_LOCK(kq);
|
|
if ((kn->kn_status & KN_INFLUX)) {
|
|
KQ_UNLOCK(kq);
|
|
continue;
|
|
}
|
|
knlist_remove_kq(knl, kn, 1, 1);
|
|
if (killkn) {
|
|
kn->kn_status |= KN_INFLUX | KN_DETACHED;
|
|
KQ_UNLOCK(kq);
|
|
knote_drop(kn, td);
|
|
} else {
|
|
/* Make sure cleared knotes disappear soon */
|
|
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
|
|
KQ_UNLOCK(kq);
|
|
}
|
|
kq = NULL;
|
|
}
|
|
|
|
if (!SLIST_EMPTY(&knl->kl_list)) {
|
|
/* there are still KN_INFLUX remaining */
|
|
kn = SLIST_FIRST(&knl->kl_list);
|
|
kq = kn->kn_kq;
|
|
KQ_LOCK(kq);
|
|
KASSERT(kn->kn_status & KN_INFLUX,
|
|
("knote removed w/o list lock"));
|
|
knl->kl_unlock(knl->kl_lockarg);
|
|
kq->kq_state |= KQ_FLUXWAIT;
|
|
msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0);
|
|
kq = NULL;
|
|
goto again;
|
|
}
|
|
|
|
if (islocked)
|
|
KNL_ASSERT_LOCKED(knl);
|
|
else {
|
|
knl->kl_unlock(knl->kl_lockarg);
|
|
KNL_ASSERT_UNLOCKED(knl);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove all knotes referencing a specified fd must be called with FILEDESC
|
|
* lock. This prevents a race where a new fd comes along and occupies the
|
|
* entry and we attach a knote to the fd.
|
|
*/
|
|
void
|
|
knote_fdclose(struct thread *td, int fd)
|
|
{
|
|
struct filedesc *fdp = td->td_proc->p_fd;
|
|
struct kqueue *kq;
|
|
struct knote *kn;
|
|
int influx;
|
|
|
|
FILEDESC_XLOCK_ASSERT(fdp);
|
|
|
|
/*
|
|
* We shouldn't have to worry about new kevents appearing on fd
|
|
* since filedesc is locked.
|
|
*/
|
|
SLIST_FOREACH(kq, &fdp->fd_kqlist, kq_list) {
|
|
KQ_LOCK(kq);
|
|
|
|
again:
|
|
influx = 0;
|
|
while (kq->kq_knlistsize > fd &&
|
|
(kn = SLIST_FIRST(&kq->kq_knlist[fd])) != NULL) {
|
|
if (kn->kn_status & KN_INFLUX) {
|
|
/* someone else might be waiting on our knote */
|
|
if (influx)
|
|
wakeup(kq);
|
|
kq->kq_state |= KQ_FLUXWAIT;
|
|
msleep(kq, &kq->kq_lock, PSOCK, "kqflxwt", 0);
|
|
goto again;
|
|
}
|
|
kn->kn_status |= KN_INFLUX;
|
|
KQ_UNLOCK(kq);
|
|
if (!(kn->kn_status & KN_DETACHED))
|
|
kn->kn_fop->f_detach(kn);
|
|
knote_drop(kn, td);
|
|
influx = 1;
|
|
KQ_LOCK(kq);
|
|
}
|
|
KQ_UNLOCK_FLUX(kq);
|
|
}
|
|
}
|
|
|
|
static int
|
|
knote_attach(struct knote *kn, struct kqueue *kq)
|
|
{
|
|
struct klist *list;
|
|
|
|
KASSERT(kn->kn_status & KN_INFLUX, ("knote not marked INFLUX"));
|
|
KQ_OWNED(kq);
|
|
|
|
if (kn->kn_fop->f_isfd) {
|
|
if (kn->kn_id >= kq->kq_knlistsize)
|
|
return ENOMEM;
|
|
list = &kq->kq_knlist[kn->kn_id];
|
|
} else {
|
|
if (kq->kq_knhash == NULL)
|
|
return ENOMEM;
|
|
list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
|
|
}
|
|
|
|
SLIST_INSERT_HEAD(list, kn, kn_link);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* knote must already have been detached using the f_detach method.
|
|
* no lock need to be held, it is assumed that the KN_INFLUX flag is set
|
|
* to prevent other removal.
|
|
*/
|
|
static void
|
|
knote_drop(struct knote *kn, struct thread *td)
|
|
{
|
|
struct kqueue *kq;
|
|
struct klist *list;
|
|
|
|
kq = kn->kn_kq;
|
|
|
|
KQ_NOTOWNED(kq);
|
|
KASSERT((kn->kn_status & KN_INFLUX) == KN_INFLUX,
|
|
("knote_drop called without KN_INFLUX set in kn_status"));
|
|
|
|
KQ_LOCK(kq);
|
|
if (kn->kn_fop->f_isfd)
|
|
list = &kq->kq_knlist[kn->kn_id];
|
|
else
|
|
list = &kq->kq_knhash[KN_HASH(kn->kn_id, kq->kq_knhashmask)];
|
|
|
|
if (!SLIST_EMPTY(list))
|
|
SLIST_REMOVE(list, kn, knote, kn_link);
|
|
if (kn->kn_status & KN_QUEUED)
|
|
knote_dequeue(kn);
|
|
KQ_UNLOCK_FLUX(kq);
|
|
|
|
if (kn->kn_fop->f_isfd) {
|
|
fdrop(kn->kn_fp, td);
|
|
kn->kn_fp = NULL;
|
|
}
|
|
kqueue_fo_release(kn->kn_kevent.filter);
|
|
kn->kn_fop = NULL;
|
|
knote_free(kn);
|
|
}
|
|
|
|
static void
|
|
knote_enqueue(struct knote *kn)
|
|
{
|
|
struct kqueue *kq = kn->kn_kq;
|
|
|
|
KQ_OWNED(kn->kn_kq);
|
|
KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
|
|
|
|
TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
|
|
kn->kn_status |= KN_QUEUED;
|
|
kq->kq_count++;
|
|
kqueue_wakeup(kq);
|
|
}
|
|
|
|
static void
|
|
knote_dequeue(struct knote *kn)
|
|
{
|
|
struct kqueue *kq = kn->kn_kq;
|
|
|
|
KQ_OWNED(kn->kn_kq);
|
|
KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
|
|
|
|
TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
|
|
kn->kn_status &= ~KN_QUEUED;
|
|
kq->kq_count--;
|
|
}
|
|
|
|
static void
|
|
knote_init(void)
|
|
{
|
|
|
|
knote_zone = uma_zcreate("KNOTE", sizeof(struct knote), NULL, NULL,
|
|
NULL, NULL, UMA_ALIGN_PTR, 0);
|
|
}
|
|
SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL);
|
|
|
|
static struct knote *
|
|
knote_alloc(int waitok)
|
|
{
|
|
return ((struct knote *)uma_zalloc(knote_zone,
|
|
(waitok ? M_WAITOK : M_NOWAIT)|M_ZERO));
|
|
}
|
|
|
|
static void
|
|
knote_free(struct knote *kn)
|
|
{
|
|
if (kn != NULL)
|
|
uma_zfree(knote_zone, kn);
|
|
}
|
|
|
|
/*
|
|
* Register the kev w/ the kq specified by fd.
|
|
*/
|
|
int
|
|
kqfd_register(int fd, struct kevent *kev, struct thread *td, int waitok)
|
|
{
|
|
struct kqueue *kq;
|
|
struct file *fp;
|
|
int error;
|
|
|
|
if ((error = fget(td, fd, CAP_POST_EVENT, &fp)) != 0)
|
|
return (error);
|
|
if ((error = kqueue_acquire(fp, &kq)) != 0)
|
|
goto noacquire;
|
|
|
|
error = kqueue_register(kq, kev, td, waitok);
|
|
|
|
kqueue_release(kq, 0);
|
|
|
|
noacquire:
|
|
fdrop(fp, td);
|
|
|
|
return error;
|
|
}
|