+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ *
+ */
+/*-
+ * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+/*
+ * @(#)kern_event.c 1.0 (3/31/2000)
+ */
+#include <stdint.h>
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/filedesc.h>
+#include <sys/kernel.h>
+#include <sys/proc_internal.h>
+#include <sys/kauth.h>
+#include <sys/malloc.h>
+#include <sys/unistd.h>
+#include <sys/file_internal.h>
+#include <sys/fcntl.h>
+#include <sys/select.h>
+#include <sys/queue.h>
+#include <sys/event.h>
+#include <sys/eventvar.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/stat.h>
+#include <sys/sysctl.h>
+#include <sys/uio.h>
+#include <sys/sysproto.h>
+#include <sys/user.h>
+#include <sys/vnode_internal.h>
+#include <string.h>
+#include <sys/proc_info.h>
+#include <sys/codesign.h>
+
+#include <kern/locks.h>
+#include <kern/clock.h>
+#include <kern/thread_call.h>
+#include <kern/sched_prim.h>
+#include <kern/wait_queue.h>
+#include <kern/zalloc.h>
+#include <kern/assert.h>
+
+#include <libkern/libkern.h>
+#include "net/net_str_id.h"
+
+#include <mach/task.h>
+
+#if VM_PRESSURE_EVENTS
+#include <kern/vm_pressure.h>
+#endif
+
+#if CONFIG_MEMORYSTATUS
+#include <sys/kern_memorystatus.h>
+#endif
+
+MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
+
+#define KQ_EVENT NULL
+
+static inline void kqlock(struct kqueue *kq);
+static inline void kqunlock(struct kqueue *kq);
+
+static int kqlock2knoteuse(struct kqueue *kq, struct knote *kn);
+static int kqlock2knoteusewait(struct kqueue *kq, struct knote *kn);
+static int kqlock2knotedrop(struct kqueue *kq, struct knote *kn);
+static int knoteuse2kqlock(struct kqueue *kq, struct knote *kn);
+
+static void kqueue_wakeup(struct kqueue *kq, int closed);
+static int kqueue_read(struct fileproc *fp, struct uio *uio,
+ int flags, vfs_context_t ctx);
+static int kqueue_write(struct fileproc *fp, struct uio *uio,
+ int flags, vfs_context_t ctx);
+static int kqueue_ioctl(struct fileproc *fp, u_long com, caddr_t data,
+ vfs_context_t ctx);
+static int kqueue_select(struct fileproc *fp, int which, void *wql,
+ vfs_context_t ctx);
+static int kqueue_close(struct fileglob *fg, vfs_context_t ctx);
+static int kqueue_kqfilter(struct fileproc *fp, struct knote *kn,
+ vfs_context_t ctx);
+static int kqueue_drain(struct fileproc *fp, vfs_context_t ctx);
+
+static const struct fileops kqueueops = {
+ .fo_type = DTYPE_KQUEUE,
+ .fo_read = kqueue_read,
+ .fo_write = kqueue_write,
+ .fo_ioctl = kqueue_ioctl,
+ .fo_select = kqueue_select,
+ .fo_close = kqueue_close,
+ .fo_kqfilter = kqueue_kqfilter,
+ .fo_drain = kqueue_drain,
+};
+
+static int kevent_internal(struct proc *p, int iskev64, user_addr_t changelist,
+ int nchanges, user_addr_t eventlist, int nevents, int fd,
+ user_addr_t utimeout, unsigned int flags, int32_t *retval);
+static int kevent_copyin(user_addr_t *addrp, struct kevent64_s *kevp,
+ struct proc *p, int iskev64);
+static int kevent_copyout(struct kevent64_s *kevp, user_addr_t *addrp,
+ struct proc *p, int iskev64);
+char * kevent_description(struct kevent64_s *kevp, char *s, size_t n);
+
+static int kevent_callback(struct kqueue *kq, struct kevent64_s *kevp,
+ void *data);
+static void kevent_continue(struct kqueue *kq, void *data, int error);
+static void kqueue_scan_continue(void *contp, wait_result_t wait_result);
+static int kqueue_process(struct kqueue *kq, kevent_callback_t callback,
+ void *data, int *countp, struct proc *p);
+static int kqueue_begin_processing(struct kqueue *kq);
+static void kqueue_end_processing(struct kqueue *kq);
+static int knote_process(struct knote *kn, kevent_callback_t callback,
+ void *data, struct kqtailq *inprocessp, struct proc *p);
+static void knote_put(struct knote *kn);
+static int knote_fdpattach(struct knote *kn, struct filedesc *fdp,
+ struct proc *p);
+static void knote_drop(struct knote *kn, struct proc *p);
+static void knote_activate(struct knote *kn, int);
+static void knote_deactivate(struct knote *kn);
+static void knote_enqueue(struct knote *kn);
+static void knote_dequeue(struct knote *kn);
+static struct knote *knote_alloc(void);
+static void knote_free(struct knote *kn);
+
+static int filt_fileattach(struct knote *kn);
+static struct filterops file_filtops = {
+ .f_isfd = 1,
+ .f_attach = filt_fileattach,
+};
+
+static void filt_kqdetach(struct knote *kn);
+static int filt_kqueue(struct knote *kn, long hint);
+static struct filterops kqread_filtops = {
+ .f_isfd = 1,
+ .f_detach = filt_kqdetach,
+ .f_event = filt_kqueue,
+};
+
+/* placeholder for not-yet-implemented filters */
+static int filt_badattach(struct knote *kn);
+static struct filterops bad_filtops = {
+ .f_attach = filt_badattach,
+};
+
+static int filt_procattach(struct knote *kn);
+static void filt_procdetach(struct knote *kn);
+static int filt_proc(struct knote *kn, long hint);
+static struct filterops proc_filtops = {
+ .f_attach = filt_procattach,
+ .f_detach = filt_procdetach,
+ .f_event = filt_proc,
+};
+
+#if VM_PRESSURE_EVENTS
+static int filt_vmattach(struct knote *kn);
+static void filt_vmdetach(struct knote *kn);
+static int filt_vm(struct knote *kn, long hint);
+static struct filterops vm_filtops = {
+ .f_attach = filt_vmattach,
+ .f_detach = filt_vmdetach,
+ .f_event = filt_vm,
+};
+#endif /* VM_PRESSURE_EVENTS */
+
+#if CONFIG_MEMORYSTATUS
+extern struct filterops memorystatus_filtops;
+#endif /* CONFIG_MEMORYSTATUS */
+
+extern struct filterops fs_filtops;
+
+extern struct filterops sig_filtops;
+
+/* Timer filter */
+static int filt_timerattach(struct knote *kn);
+static void filt_timerdetach(struct knote *kn);
+static int filt_timer(struct knote *kn, long hint);
+static void filt_timertouch(struct knote *kn, struct kevent64_s *kev,
+ long type);
+static struct filterops timer_filtops = {
+ .f_attach = filt_timerattach,
+ .f_detach = filt_timerdetach,
+ .f_event = filt_timer,
+ .f_touch = filt_timertouch,
+};
+
+/* Helpers */
+static void filt_timerexpire(void *knx, void *param1);
+static int filt_timervalidate(struct knote *kn);
+static void filt_timerupdate(struct knote *kn);
+static void filt_timercancel(struct knote *kn);
+
+#define TIMER_RUNNING 0x1
+#define TIMER_CANCELWAIT 0x2
+
+static lck_mtx_t _filt_timerlock;
+static void filt_timerlock(void);
+static void filt_timerunlock(void);
+
+static zone_t knote_zone;
+
+#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
+
+#if 0
+extern struct filterops aio_filtops;
+#endif
+
+/* Mach portset filter */
+extern struct filterops machport_filtops;
+
+/* User filter */
+static int filt_userattach(struct knote *kn);
+static void filt_userdetach(struct knote *kn);
+static int filt_user(struct knote *kn, long hint);
+static void filt_usertouch(struct knote *kn, struct kevent64_s *kev,
+ long type);
+static struct filterops user_filtops = {
+ .f_attach = filt_userattach,
+ .f_detach = filt_userdetach,
+ .f_event = filt_user,
+ .f_touch = filt_usertouch,
+};
+
+/*
+ * Table for all system-defined filters.
+ */
+static struct filterops *sysfilt_ops[] = {
+ &file_filtops, /* EVFILT_READ */
+ &file_filtops, /* EVFILT_WRITE */
+#if 0
+ &aio_filtops, /* EVFILT_AIO */
+#else
+ &bad_filtops, /* EVFILT_AIO */
+#endif
+ &file_filtops, /* EVFILT_VNODE */
+ &proc_filtops, /* EVFILT_PROC */
+ &sig_filtops, /* EVFILT_SIGNAL */
+ &timer_filtops, /* EVFILT_TIMER */
+ &machport_filtops, /* EVFILT_MACHPORT */
+ &fs_filtops, /* EVFILT_FS */
+ &user_filtops, /* EVFILT_USER */
+ &bad_filtops, /* unused */
+#if VM_PRESSURE_EVENTS
+ &vm_filtops, /* EVFILT_VM */
+#else
+ &bad_filtops, /* EVFILT_VM */
+#endif
+ &file_filtops, /* EVFILT_SOCK */
+#if CONFIG_MEMORYSTATUS
+ &memorystatus_filtops, /* EVFILT_MEMORYSTATUS */
+#else
+ &bad_filtops, /* EVFILT_MEMORYSTATUS */
+#endif
+};
+
+/*
+ * kqueue/note lock attributes and implementations
+ *
+ * kqueues have locks, while knotes have use counts
+ * Most of the knote state is guarded by the object lock.
+ * the knote "inuse" count and status use the kqueue lock.
+ */
+lck_grp_attr_t * kq_lck_grp_attr;
+lck_grp_t * kq_lck_grp;
+lck_attr_t * kq_lck_attr;
+
+static inline void
+kqlock(struct kqueue *kq)
+{
+ lck_spin_lock(&kq->kq_lock);
+}
+
+static inline void
+kqunlock(struct kqueue *kq)
+{
+ lck_spin_unlock(&kq->kq_lock);
+}
+
+/*
+ * Convert a kq lock to a knote use referece.
+ *
+ * If the knote is being dropped, we can't get
+ * a use reference, so just return with it
+ * still locked.
+ * - kq locked at entry
+ * - unlock on exit if we get the use reference
+ */
+static int
+kqlock2knoteuse(struct kqueue *kq, struct knote *kn)
+{
+ if (kn->kn_status & KN_DROPPING)
+ return (0);
+ kn->kn_inuse++;
+ kqunlock(kq);
+ return (1);
+}
+
+/*
+ * Convert a kq lock to a knote use referece,
+ * but wait for attach and drop events to complete.
+ *
+ * If the knote is being dropped, we can't get
+ * a use reference, so just return with it
+ * still locked.
+ * - kq locked at entry
+ * - kq always unlocked on exit
+ */
+static int
+kqlock2knoteusewait(struct kqueue *kq, struct knote *kn)
+{
+ if ((kn->kn_status & (KN_DROPPING | KN_ATTACHING)) != 0) {
+ kn->kn_status |= KN_USEWAIT;
+ wait_queue_assert_wait((wait_queue_t)kq->kq_wqs,
+ &kn->kn_status, THREAD_UNINT, 0);
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ return (0);
+ }
+ kn->kn_inuse++;
+ kqunlock(kq);
+ return (1);
+}
+
+/*
+ * Convert from a knote use reference back to kq lock.
+ *
+ * Drop a use reference and wake any waiters if
+ * this is the last one.
+ *
+ * The exit return indicates if the knote is
+ * still alive - but the kqueue lock is taken
+ * unconditionally.
+ */
+static int
+knoteuse2kqlock(struct kqueue *kq, struct knote *kn)
+{
+ kqlock(kq);
+ if (--kn->kn_inuse == 0) {
+ if ((kn->kn_status & KN_ATTACHING) != 0) {
+ kn->kn_status &= ~KN_ATTACHING;
+ }
+ if ((kn->kn_status & KN_USEWAIT) != 0) {
+ kn->kn_status &= ~KN_USEWAIT;
+ wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs,
+ &kn->kn_status, THREAD_AWAKENED);
+ }
+ }
+ return ((kn->kn_status & KN_DROPPING) == 0);
+}
+
+/*
+ * Convert a kq lock to a knote drop reference.
+ *
+ * If the knote is in use, wait for the use count
+ * to subside. We first mark our intention to drop
+ * it - keeping other users from "piling on."
+ * If we are too late, we have to wait for the
+ * other drop to complete.
+ *
+ * - kq locked at entry
+ * - always unlocked on exit.
+ * - caller can't hold any locks that would prevent
+ * the other dropper from completing.
+ */
+static int
+kqlock2knotedrop(struct kqueue *kq, struct knote *kn)
+{
+ int oktodrop;
+
+ oktodrop = ((kn->kn_status & (KN_DROPPING | KN_ATTACHING)) == 0);
+ kn->kn_status &= ~KN_STAYQUEUED;
+ kn->kn_status |= KN_DROPPING;
+ if (oktodrop) {
+ if (kn->kn_inuse == 0) {
+ kqunlock(kq);
+ return (oktodrop);
+ }
+ }
+ kn->kn_status |= KN_USEWAIT;
+ wait_queue_assert_wait((wait_queue_t)kq->kq_wqs, &kn->kn_status,
+ THREAD_UNINT, 0);
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ return (oktodrop);
+}
+
+/*
+ * Release a knote use count reference.
+ */
+static void
+knote_put(struct knote *kn)
+{
+ struct kqueue *kq = kn->kn_kq;
+
+ kqlock(kq);
+ if (--kn->kn_inuse == 0) {
+ if ((kn->kn_status & KN_USEWAIT) != 0) {
+ kn->kn_status &= ~KN_USEWAIT;
+ wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs,
+ &kn->kn_status, THREAD_AWAKENED);
+ }
+ }
+ kqunlock(kq);
+}
+
+static int
+filt_fileattach(struct knote *kn)
+{
+ return (fo_kqfilter(kn->kn_fp, kn, vfs_context_current()));
+}
+
+#define f_flag f_fglob->fg_flag
+#define f_msgcount f_fglob->fg_msgcount
+#define f_cred f_fglob->fg_cred
+#define f_ops f_fglob->fg_ops
+#define f_offset f_fglob->fg_offset
+#define f_data f_fglob->fg_data
+
+static void
+filt_kqdetach(struct knote *kn)
+{
+ struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+
+ kqlock(kq);
+ KNOTE_DETACH(&kq->kq_sel.si_note, kn);
+ kqunlock(kq);
+}
+
+/*ARGSUSED*/
+static int
+filt_kqueue(struct knote *kn, __unused long hint)
+{
+ struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+
+ kn->kn_data = kq->kq_count;
+ return (kn->kn_data > 0);
+}
+
+static int
+filt_procattach(struct knote *kn)
+{
+ struct proc *p;
+
+ assert(PID_MAX < NOTE_PDATAMASK);
+
+ if ((kn->kn_sfflags & (NOTE_TRACK | NOTE_TRACKERR | NOTE_CHILD)) != 0)
+ return (ENOTSUP);
+
+ p = proc_find(kn->kn_id);
+ if (p == NULL) {
+ return (ESRCH);
+ }
+
+ const int NoteExitStatusBits = NOTE_EXIT | NOTE_EXITSTATUS;
+
+ if ((kn->kn_sfflags & NoteExitStatusBits) == NoteExitStatusBits)
+ do {
+ pid_t selfpid = proc_selfpid();
+
+ if (p->p_ppid == selfpid)
+ break; /* parent => ok */
+
+ if ((p->p_lflag & P_LTRACED) != 0 &&
+ (p->p_oppid == selfpid))
+ break; /* parent-in-waiting => ok */
+
+ proc_rele(p);
+ return (EACCES);
+ } while (0);
+
+ proc_klist_lock();
+
+ kn->kn_flags |= EV_CLEAR; /* automatically set */
+ kn->kn_ptr.p_proc = p; /* store the proc handle */
+
+ KNOTE_ATTACH(&p->p_klist, kn);
+
+ proc_klist_unlock();
+
+ proc_rele(p);
+
+ return (0);
+}
+
+/*
+ * The knote may be attached to a different process, which may exit,
+ * leaving nothing for the knote to be attached to. In that case,
+ * the pointer to the process will have already been nulled out.
+ */
+static void
+filt_procdetach(struct knote *kn)
+{
+ struct proc *p;
+
+ proc_klist_lock();
+
+ p = kn->kn_ptr.p_proc;
+ if (p != PROC_NULL) {
+ kn->kn_ptr.p_proc = PROC_NULL;
+ KNOTE_DETACH(&p->p_klist, kn);
+ }
+
+ proc_klist_unlock();
+}
+
+static int
+filt_proc(struct knote *kn, long hint)
+{
+ /*
+ * Note: a lot of bits in hint may be obtained from the knote
+ * To free some of those bits, see <rdar://problem/12592988> Freeing up
+ * bits in hint for filt_proc
+ */
+ /* hint is 0 when called from above */
+ if (hint != 0) {
+ u_int event;
+
+ /* ALWAYS CALLED WITH proc_klist_lock when (hint != 0) */
+
+ /*
+ * mask off extra data
+ */
+ event = (u_int)hint & NOTE_PCTRLMASK;
+
+ /*
+ * termination lifecycle events can happen while a debugger
+ * has reparented a process, in which case notifications
+ * should be quashed except to the tracing parent. When
+ * the debugger reaps the child (either via wait4(2) or
+ * process exit), the child will be reparented to the original
+ * parent and these knotes re-fired.
+ */
+ if (event & NOTE_EXIT) {
+ if ((kn->kn_ptr.p_proc->p_oppid != 0)
+ && (kn->kn_kq->kq_p->p_pid != kn->kn_ptr.p_proc->p_ppid)) {
+ /*
+ * This knote is not for the current ptrace(2) parent, ignore.
+ */
+ return 0;
+ }
+ }
+
+ /*
+ * if the user is interested in this event, record it.
+ */
+ if (kn->kn_sfflags & event)
+ kn->kn_fflags |= event;
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+ if ((event == NOTE_REAP) || ((event == NOTE_EXIT) && !(kn->kn_sfflags & NOTE_REAP))) {
+ kn->kn_flags |= (EV_EOF | EV_ONESHOT);
+ }
+#pragma clang diagnostic pop
+
+
+ /*
+ * The kernel has a wrapper in place that returns the same data
+ * as is collected here, in kn_data. Any changes to how
+ * NOTE_EXITSTATUS and NOTE_EXIT_DETAIL are collected
+ * should also be reflected in the proc_pidnoteexit() wrapper.
+ */
+ if (event == NOTE_EXIT) {
+ kn->kn_data = 0;
+ if ((kn->kn_sfflags & NOTE_EXITSTATUS) != 0) {
+ kn->kn_fflags |= NOTE_EXITSTATUS;
+ kn->kn_data |= (hint & NOTE_PDATAMASK);
+ }
+ if ((kn->kn_sfflags & NOTE_EXIT_DETAIL) != 0) {
+ kn->kn_fflags |= NOTE_EXIT_DETAIL;
+ if ((kn->kn_ptr.p_proc->p_lflag &
+ P_LTERM_DECRYPTFAIL) != 0) {
+ kn->kn_data |= NOTE_EXIT_DECRYPTFAIL;
+ }
+ if ((kn->kn_ptr.p_proc->p_lflag &
+ P_LTERM_JETSAM) != 0) {
+ kn->kn_data |= NOTE_EXIT_MEMORY;
+ switch (kn->kn_ptr.p_proc->p_lflag &
+ P_JETSAM_MASK) {
+ case P_JETSAM_VMPAGESHORTAGE:
+ kn->kn_data |= NOTE_EXIT_MEMORY_VMPAGESHORTAGE;
+ break;
+ case P_JETSAM_VMTHRASHING:
+ kn->kn_data |= NOTE_EXIT_MEMORY_VMTHRASHING;
+ break;
+ case P_JETSAM_FCTHRASHING:
+ kn->kn_data |= NOTE_EXIT_MEMORY_FCTHRASHING;
+ break;
+ case P_JETSAM_VNODE:
+ kn->kn_data |= NOTE_EXIT_MEMORY_VNODE;
+ break;
+ case P_JETSAM_HIWAT:
+ kn->kn_data |= NOTE_EXIT_MEMORY_HIWAT;
+ break;
+ case P_JETSAM_PID:
+ kn->kn_data |= NOTE_EXIT_MEMORY_PID;
+ break;
+ case P_JETSAM_IDLEEXIT:
+ kn->kn_data |= NOTE_EXIT_MEMORY_IDLE;
+ break;
+ }
+ }
+ if ((kn->kn_ptr.p_proc->p_csflags &
+ CS_KILLED) != 0) {
+ kn->kn_data |= NOTE_EXIT_CSERROR;
+ }
+ }
+ }
+ }
+
+ /* atomic check, no locking need when called from above */
+ return (kn->kn_fflags != 0);
+}
+
+#if VM_PRESSURE_EVENTS
+/*
+ * Virtual memory kevents
+ *
+ * author: Matt Jacobson [matthew_jacobson@apple.com]
+ */
+
+static int
+filt_vmattach(struct knote *kn)
+{
+ /*
+ * The note will be cleared once the information has been flushed to
+ * the client. If there is still pressure, we will be re-alerted.
+ */
+ kn->kn_flags |= EV_CLEAR;
+ return (vm_knote_register(kn));
+}
+
+static void
+filt_vmdetach(struct knote *kn)
+{
+ vm_knote_unregister(kn);
+}
+
+static int
+filt_vm(struct knote *kn, long hint)
+{
+ /* hint == 0 means this is just an alive? check (always true) */
+ if (hint != 0) {
+ const pid_t pid = (pid_t)hint;
+ if ((kn->kn_sfflags & NOTE_VM_PRESSURE) &&
+ (kn->kn_kq->kq_p->p_pid == pid)) {
+ kn->kn_fflags |= NOTE_VM_PRESSURE;
+ }
+ }
+
+ return (kn->kn_fflags != 0);
+}
+#endif /* VM_PRESSURE_EVENTS */
+
+/*
+ * filt_timervalidate - process data from user
+ *
+ * Converts to either interval or deadline format.
+ *
+ * The saved-data field in the knote contains the
+ * time value. The saved filter-flags indicates
+ * the unit of measurement.
+ *
+ * After validation, either the saved-data field
+ * contains the interval in absolute time, or ext[0]
+ * contains the expected deadline. If that deadline
+ * is in the past, ext[0] is 0.
+ *
+ * Returns EINVAL for unrecognized units of time.
+ *
+ * Timer filter lock is held.
+ *
+ */
+static int
+filt_timervalidate(struct knote *kn)
+{
+ uint64_t multiplier;
+ uint64_t raw = 0;
+
+ switch (kn->kn_sfflags & (NOTE_SECONDS|NOTE_USECONDS|NOTE_NSECONDS)) {
+ case NOTE_SECONDS:
+ multiplier = NSEC_PER_SEC;
+ break;
+ case NOTE_USECONDS:
+ multiplier = NSEC_PER_USEC;
+ break;
+ case NOTE_NSECONDS:
+ multiplier = 1;
+ break;
+ case 0: /* milliseconds (default) */
+ multiplier = NSEC_PER_SEC / 1000;
+ break;
+ default:
+ return (EINVAL);
+ }
+
+ /* transform the slop delta(leeway) in kn_ext[1] if passed to same time scale */
+ if(kn->kn_sfflags & NOTE_LEEWAY){
+ nanoseconds_to_absolutetime((uint64_t)kn->kn_ext[1] * multiplier, &raw);
+ kn->kn_ext[1] = raw;
+ }
+
+ nanoseconds_to_absolutetime((uint64_t)kn->kn_sdata * multiplier, &raw);
+
+ kn->kn_ext[0] = 0;
+ kn->kn_sdata = 0;
+
+ if (kn->kn_sfflags & NOTE_ABSOLUTE) {
+ clock_sec_t seconds;
+ clock_nsec_t nanoseconds;
+ uint64_t now;
+
+ clock_get_calendar_nanotime(&seconds, &nanoseconds);
+ nanoseconds_to_absolutetime((uint64_t)seconds * NSEC_PER_SEC +
+ nanoseconds, &now);
+
+ if (raw < now) {
+ /* time has already passed */
+ kn->kn_ext[0] = 0;
+ } else {
+ raw -= now;
+ clock_absolutetime_interval_to_deadline(raw,
+ &kn->kn_ext[0]);
+ }
+ } else {
+ kn->kn_sdata = raw;
+ }
+
+ return (0);
+}
+
+/*
+ * filt_timerupdate - compute the next deadline
+ *
+ * Repeating timers store their interval in kn_sdata. Absolute
+ * timers have already calculated the deadline, stored in ext[0].
+ *
+ * On return, the next deadline (or zero if no deadline is needed)
+ * is stored in kn_ext[0].
+ *
+ * Timer filter lock is held.
+ */
+static void
+filt_timerupdate(struct knote *kn)
+{
+ /* if there's no interval, deadline is just in kn_ext[0] */
+ if (kn->kn_sdata == 0)
+ return;
+
+ /* if timer hasn't fired before, fire in interval nsecs */
+ if (kn->kn_ext[0] == 0) {
+ clock_absolutetime_interval_to_deadline(kn->kn_sdata,
+ &kn->kn_ext[0]);
+ } else {
+ /*
+ * If timer has fired before, schedule the next pop
+ * relative to the last intended deadline.
+ *
+ * We could check for whether the deadline has expired,
+ * but the thread call layer can handle that.
+ */
+ kn->kn_ext[0] += kn->kn_sdata;
+ }
+}
+
+/*
+ * filt_timerexpire - the timer callout routine
+ *
+ * Just propagate the timer event into the knote
+ * filter routine (by going through the knote
+ * synchronization point). Pass a hint to
+ * indicate this is a real event, not just a
+ * query from above.
+ */
+static void
+filt_timerexpire(void *knx, __unused void *spare)
+{
+ struct klist timer_list;
+ struct knote *kn = knx;
+
+ filt_timerlock();
+
+ kn->kn_hookid &= ~TIMER_RUNNING;
+
+ /* no "object" for timers, so fake a list */
+ SLIST_INIT(&timer_list);
+ SLIST_INSERT_HEAD(&timer_list, kn, kn_selnext);
+ KNOTE(&timer_list, 1);
+
+ /* if someone is waiting for timer to pop */
+ if (kn->kn_hookid & TIMER_CANCELWAIT) {
+ struct kqueue *kq = kn->kn_kq;
+ wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, &kn->kn_hook,
+ THREAD_AWAKENED);
+ }
+
+ filt_timerunlock();
+}
+
+/*
+ * Cancel a running timer (or wait for the pop).
+ * Timer filter lock is held.
+ */
+static void
+filt_timercancel(struct knote *kn)
+{
+ struct kqueue *kq = kn->kn_kq;
+ thread_call_t callout = kn->kn_hook;
+ boolean_t cancelled;
+
+ if (kn->kn_hookid & TIMER_RUNNING) {
+ /* cancel the callout if we can */
+ cancelled = thread_call_cancel(callout);
+ if (cancelled) {
+ kn->kn_hookid &= ~TIMER_RUNNING;
+ } else {
+ /* we have to wait for the expire routine. */
+ kn->kn_hookid |= TIMER_CANCELWAIT;
+ wait_queue_assert_wait((wait_queue_t)kq->kq_wqs,
+ &kn->kn_hook, THREAD_UNINT, 0);
+ filt_timerunlock();
+ thread_block(THREAD_CONTINUE_NULL);
+ filt_timerlock();
+ assert((kn->kn_hookid & TIMER_RUNNING) == 0);
+ }
+ }
+}
+
+/*
+ * Allocate a thread call for the knote's lifetime, and kick off the timer.
+ */
+static int
+filt_timerattach(struct knote *kn)
+{
+ thread_call_t callout;
+ int error;
+
+ callout = thread_call_allocate(filt_timerexpire, kn);
+ if (NULL == callout)
+ return (ENOMEM);
+
+ filt_timerlock();
+ error = filt_timervalidate(kn);
+ if (error != 0) {
+ filt_timerunlock();
+ return (error);
+ }
+
+ kn->kn_hook = (void*)callout;
+ kn->kn_hookid = 0;
+
+ /* absolute=EV_ONESHOT */
+ if (kn->kn_sfflags & NOTE_ABSOLUTE)
+ kn->kn_flags |= EV_ONESHOT;
+
+ filt_timerupdate(kn);
+ if (kn->kn_ext[0]) {
+ kn->kn_flags |= EV_CLEAR;
+ unsigned int timer_flags = 0;
+ if (kn->kn_sfflags & NOTE_CRITICAL)
+ timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL;
+ else if (kn->kn_sfflags & NOTE_BACKGROUND)
+ timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND;
+ else
+ timer_flags |= THREAD_CALL_DELAY_USER_NORMAL;
+
+ if (kn->kn_sfflags & NOTE_LEEWAY)
+ timer_flags |= THREAD_CALL_DELAY_LEEWAY;
+
+ thread_call_enter_delayed_with_leeway(callout, NULL,
+ kn->kn_ext[0], kn->kn_ext[1], timer_flags);
+
+ kn->kn_hookid |= TIMER_RUNNING;
+ } else {
+ /* fake immediate */
+ kn->kn_data = 1;
+ }
+
+ filt_timerunlock();
+ return (0);
+}
+
+/*
+ * Shut down the timer if it's running, and free the callout.
+ */
+static void
+filt_timerdetach(struct knote *kn)
+{
+ thread_call_t callout;
+
+ filt_timerlock();
+
+ callout = (thread_call_t)kn->kn_hook;
+ filt_timercancel(kn);
+
+ filt_timerunlock();
+
+ thread_call_free(callout);
+}
+
+
+
+static int
+filt_timer(struct knote *kn, long hint)
+{
+ int result;
+
+ if (hint) {
+ /* real timer pop -- timer lock held by filt_timerexpire */
+ kn->kn_data++;
+
+ if (((kn->kn_hookid & TIMER_CANCELWAIT) == 0) &&
+ ((kn->kn_flags & EV_ONESHOT) == 0)) {
+
+ /* evaluate next time to fire */
+ filt_timerupdate(kn);
+
+ if (kn->kn_ext[0]) {
+ unsigned int timer_flags = 0;
+
+ /* keep the callout and re-arm */
+ if (kn->kn_sfflags & NOTE_CRITICAL)
+ timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL;
+ else if (kn->kn_sfflags & NOTE_BACKGROUND)
+ timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND;
+ else
+ timer_flags |= THREAD_CALL_DELAY_USER_NORMAL;
+
+ if (kn->kn_sfflags & NOTE_LEEWAY)
+ timer_flags |= THREAD_CALL_DELAY_LEEWAY;
+
+ thread_call_enter_delayed_with_leeway(kn->kn_hook, NULL,
+ kn->kn_ext[0], kn->kn_ext[1], timer_flags);
+
+ kn->kn_hookid |= TIMER_RUNNING;
+ }
+ }
+
+ return (1);
+ }
+
+ /* user-query */
+ filt_timerlock();
+
+ result = (kn->kn_data != 0);
+
+ filt_timerunlock();
+
+ return (result);
+}
+
+
+/*
+ * filt_timertouch - update knote with new user input
+ *
+ * Cancel and restart the timer based on new user data. When
+ * the user picks up a knote, clear the count of how many timer
+ * pops have gone off (in kn_data).
+ */
+static void
+filt_timertouch(struct knote *kn, struct kevent64_s *kev, long type)
+{
+ int error;
+ filt_timerlock();
+
+ switch (type) {
+ case EVENT_REGISTER:
+ /* cancel current call */
+ filt_timercancel(kn);
+
+ /* recalculate deadline */
+ kn->kn_sdata = kev->data;
+ kn->kn_sfflags = kev->fflags;
+ kn->kn_ext[0] = kev->ext[0];
+ kn->kn_ext[1] = kev->ext[1];
+
+ error = filt_timervalidate(kn);
+ if (error) {
+ /* no way to report error, so mark it in the knote */
+ kn->kn_flags |= EV_ERROR;
+ kn->kn_data = error;
+ break;
+ }
+
+ /* start timer if necessary */
+ filt_timerupdate(kn);
+
+ if (kn->kn_ext[0]) {
+ unsigned int timer_flags = 0;
+ if (kn->kn_sfflags & NOTE_CRITICAL)
+ timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL;
+ else if (kn->kn_sfflags & NOTE_BACKGROUND)
+ timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND;
+ else
+ timer_flags |= THREAD_CALL_DELAY_USER_NORMAL;
+
+ if (kn->kn_sfflags & NOTE_LEEWAY)
+ timer_flags |= THREAD_CALL_DELAY_LEEWAY;
+
+ thread_call_enter_delayed_with_leeway(kn->kn_hook, NULL,
+ kn->kn_ext[0], kn->kn_ext[1], timer_flags);
+
+ kn->kn_hookid |= TIMER_RUNNING;
+ } else {
+ /* pretend the timer has fired */
+ kn->kn_data = 1;
+ }
+
+ break;
+
+ case EVENT_PROCESS:
+ /* reset the timer pop count in kn_data */
+ *kev = kn->kn_kevent;
+ kev->ext[0] = 0;
+ kn->kn_data = 0;
+ if (kn->kn_flags & EV_CLEAR)
+ kn->kn_fflags = 0;
+ break;
+ default:
+ panic("%s: - invalid type (%ld)", __func__, type);
+ break;
+ }
+
+ filt_timerunlock();
+}
+
+static void
+filt_timerlock(void)
+{
+ lck_mtx_lock(&_filt_timerlock);
+}
+
+static void
+filt_timerunlock(void)
+{
+ lck_mtx_unlock(&_filt_timerlock);
+}
+
+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 kevent64_s *kev, long type)
+{
+ uint32_t 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:
+ OSBitAndAtomic(kev->fflags, &kn->kn_sfflags);
+ break;
+ case NOTE_FFOR:
+ OSBitOrAtomic(kev->fflags, &kn->kn_sfflags);
+ break;
+ case NOTE_FFCOPY:
+ kn->kn_sfflags = kev->fflags;
+ break;
+ }
+ kn->kn_sdata = kev->data;
+ break;
+ case EVENT_PROCESS:
+ *kev = kn->kn_kevent;
+ kev->fflags = (volatile UInt32)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("%s: - invalid type (%ld)", __func__, type);
+ break;
+ }
+}
+
+/*
+ * JMM - placeholder for not-yet-implemented filters
+ */
+static int
+filt_badattach(__unused struct knote *kn)
+{
+ return (ENOTSUP);
+}
+
+struct kqueue *
+kqueue_alloc(struct proc *p)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct kqueue *kq;
+
+ MALLOC_ZONE(kq, struct kqueue *, sizeof (struct kqueue), M_KQUEUE,
+ M_WAITOK);
+ if (kq != NULL) {
+ wait_queue_set_t wqs;
+
+ wqs = wait_queue_set_alloc(SYNC_POLICY_FIFO |
+ SYNC_POLICY_PREPOST);
+ if (wqs != NULL) {
+ bzero(kq, sizeof (struct kqueue));
+ lck_spin_init(&kq->kq_lock, kq_lck_grp, kq_lck_attr);
+ TAILQ_INIT(&kq->kq_head);
+ kq->kq_wqs = wqs;
+ kq->kq_p = p;
+ } else {
+ FREE_ZONE(kq, sizeof (struct kqueue), M_KQUEUE);
+ kq = NULL;
+ }
+ }
+
+ if (fdp->fd_knlistsize < 0) {
+ proc_fdlock(p);
+ if (fdp->fd_knlistsize < 0)
+ fdp->fd_knlistsize = 0; /* this process has had a kq */
+ proc_fdunlock(p);
+ }
+
+ return (kq);
+}
+
+/*
+ * kqueue_dealloc - detach all knotes from a kqueue and free it
+ *
+ * We walk each list looking for knotes referencing this
+ * this kqueue. If we find one, we try to drop it. But
+ * if we fail to get a drop reference, that will wait
+ * until it is dropped. So, we can just restart again
+ * safe in the assumption that the list will eventually
+ * not contain any more references to this kqueue (either
+ * we dropped them all, or someone else did).
+ *
+ * Assumes no new events are being added to the kqueue.
+ * Nothing locked on entry or exit.
+ */
+void
+kqueue_dealloc(struct kqueue *kq)
+{
+ struct proc *p = kq->kq_p;
+ struct filedesc *fdp = p->p_fd;
+ struct knote *kn;
+ int i;
+
+ proc_fdlock(p);
+ for (i = 0; i < fdp->fd_knlistsize; i++) {
+ kn = SLIST_FIRST(&fdp->fd_knlist[i]);
+ while (kn != NULL) {
+ if (kq == kn->kn_kq) {
+ kqlock(kq);
+ proc_fdunlock(p);
+ /* drop it ourselves or wait */
+ if (kqlock2knotedrop(kq, kn)) {
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ }
+ proc_fdlock(p);
+ /* start over at beginning of list */
+ kn = SLIST_FIRST(&fdp->fd_knlist[i]);
+ continue;
+ }
+ kn = SLIST_NEXT(kn, kn_link);
+ }
+ }
+ if (fdp->fd_knhashmask != 0) {
+ for (i = 0; i < (int)fdp->fd_knhashmask + 1; i++) {
+ kn = SLIST_FIRST(&fdp->fd_knhash[i]);
+ while (kn != NULL) {
+ if (kq == kn->kn_kq) {
+ kqlock(kq);
+ proc_fdunlock(p);
+ /* drop it ourselves or wait */
+ if (kqlock2knotedrop(kq, kn)) {
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ }
+ proc_fdlock(p);
+ /* start over at beginning of list */
+ kn = SLIST_FIRST(&fdp->fd_knhash[i]);
+ continue;
+ }
+ kn = SLIST_NEXT(kn, kn_link);
+ }
+ }
+ }
+ proc_fdunlock(p);
+
+ /*
+ * before freeing the wait queue set for this kqueue,
+ * make sure it is unlinked from all its containing (select) sets.
+ */
+ wait_queue_unlink_all((wait_queue_t)kq->kq_wqs);
+ wait_queue_set_free(kq->kq_wqs);
+ lck_spin_destroy(&kq->kq_lock, kq_lck_grp);
+ FREE_ZONE(kq, sizeof (struct kqueue), M_KQUEUE);
+}
+
+int
+kqueue_body(struct proc *p, fp_allocfn_t fp_zalloc, void *cra, int32_t *retval)
+{
+ struct kqueue *kq;
+ struct fileproc *fp;
+ int fd, error;
+
+ error = falloc_withalloc(p,
+ &fp, &fd, vfs_context_current(), fp_zalloc, cra);
+ if (error) {
+ return (error);
+ }
+
+ kq = kqueue_alloc(p);
+ if (kq == NULL) {
+ fp_free(p, fd, fp);
+ return (ENOMEM);
+ }
+
+ fp->f_flag = FREAD | FWRITE;
+ fp->f_ops = &kqueueops;
+ fp->f_data = kq;
+
+ proc_fdlock(p);
+ *fdflags(p, fd) |= UF_EXCLOSE;
+ procfdtbl_releasefd(p, fd, NULL);
+ fp_drop(p, fd, fp, 1);
+ proc_fdunlock(p);
+
+ *retval = fd;
+ return (error);
+}
+
+int
+kqueue(struct proc *p, __unused struct kqueue_args *uap, int32_t *retval)
+{
+ return (kqueue_body(p, fileproc_alloc_init, NULL, retval));
+}
+
+static int
+kevent_copyin(user_addr_t *addrp, struct kevent64_s *kevp, struct proc *p,
+ int iskev64)
+{
+ int advance;
+ int error;
+
+ if (iskev64) {
+ advance = sizeof (struct kevent64_s);
+ error = copyin(*addrp, (caddr_t)kevp, advance);
+ } else if (IS_64BIT_PROCESS(p)) {
+ struct user64_kevent kev64;
+ bzero(kevp, sizeof (struct kevent64_s));
+
+ advance = sizeof (kev64);
+ error = copyin(*addrp, (caddr_t)&kev64, advance);
+ if (error)
+ return (error);
+ kevp->ident = kev64.ident;
+ kevp->filter = kev64.filter;
+ kevp->flags = kev64.flags;
+ kevp->fflags = kev64.fflags;
+ kevp->data = kev64.data;
+ kevp->udata = kev64.udata;
+ } else {
+ struct user32_kevent kev32;
+ bzero(kevp, sizeof (struct kevent64_s));
+
+ advance = sizeof (kev32);
+ error = copyin(*addrp, (caddr_t)&kev32, advance);
+ if (error)
+ return (error);
+ kevp->ident = (uintptr_t)kev32.ident;
+ kevp->filter = kev32.filter;
+ kevp->flags = kev32.flags;
+ kevp->fflags = kev32.fflags;
+ kevp->data = (intptr_t)kev32.data;
+ kevp->udata = CAST_USER_ADDR_T(kev32.udata);
+ }
+ if (!error)
+ *addrp += advance;
+ return (error);
+}
+
+static int
+kevent_copyout(struct kevent64_s *kevp, user_addr_t *addrp, struct proc *p,
+ int iskev64)
+{
+ int advance;
+ int error;
+
+ if (iskev64) {
+ advance = sizeof (struct kevent64_s);
+ error = copyout((caddr_t)kevp, *addrp, advance);
+ } else if (IS_64BIT_PROCESS(p)) {
+ struct user64_kevent kev64;
+
+ /*
+ * deal with the special case of a user-supplied
+ * value of (uintptr_t)-1.
+ */
+ kev64.ident = (kevp->ident == (uintptr_t)-1) ?
+ (uint64_t)-1LL : (uint64_t)kevp->ident;
+
+ kev64.filter = kevp->filter;
+ kev64.flags = kevp->flags;
+ kev64.fflags = kevp->fflags;
+ kev64.data = (int64_t) kevp->data;
+ kev64.udata = kevp->udata;
+ advance = sizeof (kev64);
+ error = copyout((caddr_t)&kev64, *addrp, advance);
+ } else {
+ struct user32_kevent kev32;
+
+ kev32.ident = (uint32_t)kevp->ident;
+ kev32.filter = kevp->filter;
+ kev32.flags = kevp->flags;
+ kev32.fflags = kevp->fflags;
+ kev32.data = (int32_t)kevp->data;
+ kev32.udata = kevp->udata;
+ advance = sizeof (kev32);
+ error = copyout((caddr_t)&kev32, *addrp, advance);
+ }
+ if (!error)
+ *addrp += advance;
+ return (error);
+}
+
+/*
+ * kevent_continue - continue a kevent syscall after blocking
+ *
+ * assume we inherit a use count on the kq fileglob.
+ */
+
+static void
+kevent_continue(__unused struct kqueue *kq, void *data, int error)
+{
+ struct _kevent *cont_args;
+ struct fileproc *fp;
+ int32_t *retval;
+ int noutputs;
+ int fd;
+ struct proc *p = current_proc();
+
+ cont_args = (struct _kevent *)data;
+ noutputs = cont_args->eventout;
+ retval = cont_args->retval;
+ fd = cont_args->fd;
+ fp = cont_args->fp;
+
+ fp_drop(p, fd, fp, 0);
+
+ /* don't restart after signals... */
+ if (error == ERESTART)
+ error = EINTR;
+ else if (error == EWOULDBLOCK)
+ error = 0;
+ if (error == 0)
+ *retval = noutputs;
+ unix_syscall_return(error);
+}
+
+/*
+ * kevent - [syscall] register and wait for kernel events
+ *
+ */
+int
+kevent(struct proc *p, struct kevent_args *uap, int32_t *retval)
+{
+ return (kevent_internal(p,
+ 0,
+ uap->changelist,
+ uap->nchanges,
+ uap->eventlist,
+ uap->nevents,
+ uap->fd,
+ uap->timeout,
+ 0, /* no flags from old kevent() call */
+ retval));
+}
+
+int
+kevent64(struct proc *p, struct kevent64_args *uap, int32_t *retval)
+{
+ return (kevent_internal(p,
+ 1,
+ uap->changelist,
+ uap->nchanges,
+ uap->eventlist,
+ uap->nevents,
+ uap->fd,
+ uap->timeout,
+ uap->flags,
+ retval));
+}
+
+static int
+kevent_internal(struct proc *p, int iskev64, user_addr_t changelist,
+ int nchanges, user_addr_t ueventlist, int nevents, int fd,
+ user_addr_t utimeout, __unused unsigned int flags,
+ int32_t *retval)
+{
+ struct _kevent *cont_args;
+ uthread_t ut;
+ struct kqueue *kq;
+ struct fileproc *fp;
+ struct kevent64_s kev;
+ int error, noutputs;
+ struct timeval atv;
+
+ /* convert timeout to absolute - if we have one */
+ if (utimeout != USER_ADDR_NULL) {
+ struct timeval rtv;
+ if (IS_64BIT_PROCESS(p)) {
+ struct user64_timespec ts;
+ error = copyin(utimeout, &ts, sizeof(ts));
+ if ((ts.tv_sec & 0xFFFFFFFF00000000ull) != 0)
+ error = EINVAL;
+ else
+ TIMESPEC_TO_TIMEVAL(&rtv, &ts);
+ } else {
+ struct user32_timespec ts;
+ error = copyin(utimeout, &ts, sizeof(ts));
+ TIMESPEC_TO_TIMEVAL(&rtv, &ts);
+ }
+ if (error)
+ return (error);
+ if (itimerfix(&rtv))
+ return (EINVAL);
+ getmicrouptime(&atv);
+ timevaladd(&atv, &rtv);
+ } else {
+ atv.tv_sec = 0;
+ atv.tv_usec = 0;
+ }
+
+ /* get a usecount for the kq itself */
+ if ((error = fp_getfkq(p, fd, &fp, &kq)) != 0)
+ return (error);
+
+ /* each kq should only be used for events of one type */
+ kqlock(kq);
+ if (kq->kq_state & (KQ_KEV32 | KQ_KEV64)) {
+ if (((iskev64 && (kq->kq_state & KQ_KEV32)) ||
+ (!iskev64 && (kq->kq_state & KQ_KEV64)))) {
+ error = EINVAL;
+ kqunlock(kq);
+ goto errorout;
+ }
+ } else {
+ kq->kq_state |= (iskev64 ? KQ_KEV64 : KQ_KEV32);
+ }
+ kqunlock(kq);
+
+ /* register all the change requests the user provided... */
+ noutputs = 0;
+ while (nchanges > 0 && error == 0) {
+ error = kevent_copyin(&changelist, &kev, p, iskev64);
+ if (error)
+ break;
+
+ kev.flags &= ~EV_SYSFLAGS;
+ error = kevent_register(kq, &kev, p);
+ if ((error || (kev.flags & EV_RECEIPT)) && nevents > 0) {
+ kev.flags = EV_ERROR;
+ kev.data = error;
+ error = kevent_copyout(&kev, &ueventlist, p, iskev64);
+ if (error == 0) {
+ nevents--;
+ noutputs++;
+ }
+ }
+ nchanges--;
+ }
+
+ /* store the continuation/completion data in the uthread */
+ ut = (uthread_t)get_bsdthread_info(current_thread());
+ cont_args = &ut->uu_kevent.ss_kevent;
+ cont_args->fp = fp;
+ cont_args->fd = fd;
+ cont_args->retval = retval;
+ cont_args->eventlist = ueventlist;
+ cont_args->eventcount = nevents;
+ cont_args->eventout = noutputs;
+ cont_args->eventsize = iskev64;
+
+ if (nevents > 0 && noutputs == 0 && error == 0)
+ error = kqueue_scan(kq, kevent_callback,
+ kevent_continue, cont_args,
+ &atv, p);
+ kevent_continue(kq, cont_args, error);
+
+errorout:
+ fp_drop(p, fd, fp, 0);
+ return (error);
+}
+
+
+/*
+ * kevent_callback - callback for each individual event
+ *
+ * called with nothing locked
+ * caller holds a reference on the kqueue
+ */
+static int
+kevent_callback(__unused struct kqueue *kq, struct kevent64_s *kevp,
+ void *data)
+{
+ struct _kevent *cont_args;
+ int error;
+ int iskev64;
+
+ cont_args = (struct _kevent *)data;
+ assert(cont_args->eventout < cont_args->eventcount);
+
+ iskev64 = cont_args->eventsize;
+
+ /*
+ * Copy out the appropriate amount of event data for this user.
+ */
+ error = kevent_copyout(kevp, &cont_args->eventlist, current_proc(),
+ iskev64);
+
+ /*
+ * If there isn't space for additional events, return
+ * a harmless error to stop the processing here
+ */
+ if (error == 0 && ++cont_args->eventout == cont_args->eventcount)
+ error = EWOULDBLOCK;
+ return (error);
+}
+
+/*
+ * kevent_description - format a description of a kevent for diagnostic output
+ *
+ * called with a 128-byte string buffer
+ */
+
+char *
+kevent_description(struct kevent64_s *kevp, char *s, size_t n)
+{
+ snprintf(s, n,
+ "kevent="
+ "{.ident=%#llx, .filter=%d, .flags=%#x, .fflags=%#x, .data=%#llx, .udata=%#llx, .ext[0]=%#llx, .ext[1]=%#llx}",
+ kevp->ident,
+ kevp->filter,
+ kevp->flags,
+ kevp->fflags,
+ kevp->data,
+ kevp->udata,
+ kevp->ext[0],
+ kevp->ext[1]);
+
+ return (s);
+}
+
+/*
+ * kevent_register - add a new event to a kqueue
+ *
+ * Creates a mapping between the event source and
+ * the kqueue via a knote data structure.
+ *
+ * Because many/most the event sources are file
+ * descriptor related, the knote is linked off
+ * the filedescriptor table for quick access.
+ *
+ * called with nothing locked
+ * caller holds a reference on the kqueue
+ */
+
+int
+kevent_register(struct kqueue *kq, struct kevent64_s *kev,
+ __unused struct proc *ctxp)
+{
+ struct proc *p = kq->kq_p;
+ struct filedesc *fdp = p->p_fd;
+ struct filterops *fops;
+ struct fileproc *fp = NULL;
+ struct knote *kn = NULL;
+ int error = 0;
+
+ if (kev->filter < 0) {
+ if (kev->filter + EVFILT_SYSCOUNT < 0)
+ return (EINVAL);
+ fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
+ } else {
+ /*
+ * XXX
+ * filter attach routine is responsible for insuring that
+ * the identifier can be attached to it.
+ */
+ printf("unknown filter: %d\n", kev->filter);
+ return (EINVAL);
+ }
+
+restart:
+ /* this iocount needs to be dropped if it is not registered */
+ proc_fdlock(p);
+ if (fops->f_isfd && (error = fp_lookup(p, kev->ident, &fp, 1)) != 0) {
+ proc_fdunlock(p);
+ return (error);
+ }
+
+ if (fops->f_isfd) {
+ /* fd-based knotes are linked off the fd table */
+ if (kev->ident < (u_int)fdp->fd_knlistsize) {
+ SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
+ if (kq == kn->kn_kq &&
+ kev->filter == kn->kn_filter)
+ break;
+ }
+ } else {
+ /* hash non-fd knotes here too */
+ if (fdp->fd_knhashmask != 0) {
+ struct klist *list;
+
+ list = &fdp->fd_knhash[
+ KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
+ SLIST_FOREACH(kn, list, kn_link)
+ if (kev->ident == kn->kn_id &&
+ kq == kn->kn_kq &&
+ kev->filter == kn->kn_filter)
+ break;
+ }
+ }
+
+ /*
+ * kn now contains the matching knote, or NULL if no match
+ */
+ if (kn == NULL) {
+ if ((kev->flags & (EV_ADD|EV_DELETE)) == EV_ADD) {
+ kn = knote_alloc();
+ if (kn == NULL) {
+ proc_fdunlock(p);
+ error = ENOMEM;
+ goto done;
+ }
+ kn->kn_fp = fp;
+ kn->kn_kq = kq;
+ kn->kn_tq = &kq->kq_head;
+ kn->kn_fop = fops;
+ kn->kn_sfflags = kev->fflags;
+ kn->kn_sdata = kev->data;
+ kev->fflags = 0;
+ kev->data = 0;
+ kn->kn_kevent = *kev;
+ kn->kn_inuse = 1; /* for f_attach() */
+ kn->kn_status = KN_ATTACHING;
+
+ /* before anyone can find it */
+ if (kev->flags & EV_DISABLE)
+ kn->kn_status |= KN_DISABLED;
+
+ error = knote_fdpattach(kn, fdp, p);
+ proc_fdunlock(p);
+
+ if (error) {
+ knote_free(kn);
+ goto done;
+ }
+
+ /*
+ * apply reference count to knote structure, and
+ * do not release it at the end of this routine.
+ */
+ fp = NULL;
+
+ error = fops->f_attach(kn);
+
+ kqlock(kq);
+
+ if (error != 0) {
+ /*
+ * Failed to attach correctly, so drop.
+ * All other possible users/droppers
+ * have deferred to us.
+ */
+ kn->kn_status |= KN_DROPPING;
+ kqunlock(kq);
+ knote_drop(kn, p);
+ goto done;
+ } else if (kn->kn_status & KN_DROPPING) {
+ /*
+ * Attach succeeded, but someone else
+ * deferred their drop - now we have
+ * to do it for them (after detaching).
+ */
+ kqunlock(kq);
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ goto done;
+ }
+ kn->kn_status &= ~KN_ATTACHING;
+ kqunlock(kq);
+ } else {
+ proc_fdunlock(p);
+ error = ENOENT;
+ goto done;
+ }
+ } else {
+ /* existing knote - get kqueue lock */
+ kqlock(kq);
+ proc_fdunlock(p);
+
+ if (kev->flags & EV_DELETE) {
+ knote_dequeue(kn);
+ kn->kn_status |= KN_DISABLED;
+ if (kqlock2knotedrop(kq, kn)) {
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ }
+ goto done;
+ }
+
+ /* update status flags for existing knote */
+ if (kev->flags & EV_DISABLE) {
+ knote_dequeue(kn);
+ kn->kn_status |= KN_DISABLED;
+ } else if (kev->flags & EV_ENABLE) {
+ kn->kn_status &= ~KN_DISABLED;
+ if (kn->kn_status & KN_ACTIVE)
+ knote_enqueue(kn);
+ }
+
+ /*
+ * The user may change some filter values after the
+ * initial EV_ADD, but doing so will not reset any
+ * filter which have already been triggered.
+ */
+ kn->kn_kevent.udata = kev->udata;
+ if (fops->f_isfd || fops->f_touch == NULL) {
+ kn->kn_sfflags = kev->fflags;
+ kn->kn_sdata = kev->data;
+ }
+
+ /*
+ * If somebody is in the middle of dropping this
+ * knote - go find/insert a new one. But we have
+ * wait for this one to go away first. Attaches
+ * running in parallel may also drop/modify the
+ * knote. Wait for those to complete as well and
+ * then start over if we encounter one.
+ */
+ if (!kqlock2knoteusewait(kq, kn)) {
+ /* kqueue, proc_fdlock both unlocked */
+ goto restart;
+ }
+
+ /*
+ * Call touch routine to notify filter of changes
+ * in filter values.
+ */
+ if (!fops->f_isfd && fops->f_touch != NULL)
+ fops->f_touch(kn, kev, EVENT_REGISTER);
+ }
+ /* still have use ref on knote */
+
+ /*
+ * If the knote is not marked to always stay enqueued,
+ * invoke the filter routine to see if it should be
+ * enqueued now.
+ */
+ if ((kn->kn_status & KN_STAYQUEUED) == 0 && kn->kn_fop->f_event(kn, 0)) {
+ if (knoteuse2kqlock(kq, kn))
+ knote_activate(kn, 1);
+ kqunlock(kq);
+ } else {
+ knote_put(kn);
+ }
+
+done:
+ if (fp != NULL)
+ fp_drop(p, kev->ident, fp, 0);
+ return (error);
+}
+
+
+/*
+ * knote_process - process a triggered event
+ *
+ * Validate that it is really still a triggered event
+ * by calling the filter routines (if necessary). Hold
+ * a use reference on the knote to avoid it being detached.
+ * If it is still considered triggered, invoke the callback
+ * routine provided and move it to the provided inprocess
+ * queue.
+ *
+ * caller holds a reference on the kqueue.
+ * kqueue locked on entry and exit - but may be dropped
+ */
+static int
+knote_process(struct knote *kn,
+ kevent_callback_t callback,
+ void *data,
+ struct kqtailq *inprocessp,
+ struct proc *p)
+{
+ struct kqueue *kq = kn->kn_kq;
+ struct kevent64_s kev;
+ int touch;
+ int result;
+ int error;
+
+ /*
+ * Determine the kevent state we want to return.
+ *
+ * Some event states need to be revalidated before returning
+ * them, others we take the snapshot at the time the event
+ * was enqueued.
+ *
+ * Events with non-NULL f_touch operations must be touched.
+ * Triggered events must fill in kev for the callback.
+ *
+ * Convert our lock to a use-count and call the event's
+ * filter routine(s) to update.
+ */
+ if ((kn->kn_status & KN_DISABLED) != 0) {
+ result = 0;
+ touch = 0;
+ } else {
+ int revalidate;
+
+ result = 1;
+ revalidate = ((kn->kn_status & KN_STAYQUEUED) != 0 ||
+ (kn->kn_flags & EV_ONESHOT) == 0);
+ touch = (!kn->kn_fop->f_isfd && kn->kn_fop->f_touch != NULL);
+
+ if (revalidate || touch) {
+ if (revalidate)
+ knote_deactivate(kn);
+
+ /* call the filter/touch routines with just a ref */
+ if (kqlock2knoteuse(kq, kn)) {
+ /* if we have to revalidate, call the filter */
+ if (revalidate) {
+ result = kn->kn_fop->f_event(kn, 0);
+ }
+
+ /*
+ * capture the kevent data - using touch if
+ * specified
+ */
+ if (result && touch) {
+ kn->kn_fop->f_touch(kn, &kev,
+ EVENT_PROCESS);
+ }
+
+ /*
+ * convert back to a kqlock - bail if the knote
+ * went away
+ */
+ if (!knoteuse2kqlock(kq, kn)) {
+ return (EJUSTRETURN);
+ } else if (result) {
+ /*
+ * if revalidated as alive, make sure
+ * it's active
+ */
+ if (!(kn->kn_status & KN_ACTIVE)) {
+ knote_activate(kn, 0);
+ }
+
+ /*
+ * capture all events that occurred
+ * during filter
+ */
+ if (!touch) {
+ kev = kn->kn_kevent;
+ }
+
+ } else if ((kn->kn_status & KN_STAYQUEUED) == 0) {
+ /*
+ * was already dequeued, so just bail on
+ * this one
+ */
+ return (EJUSTRETURN);
+ }
+ } else {
+ return (EJUSTRETURN);
+ }
+ } else {
+ kev = kn->kn_kevent;
+ }
+ }
+
+ /* move knote onto inprocess queue */
+ assert(kn->kn_tq == &kq->kq_head);
+ TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
+ kn->kn_tq = inprocessp;
+ TAILQ_INSERT_TAIL(inprocessp, kn, kn_tqe);
+
+ /*
+ * Determine how to dispatch the knote for future event handling.
+ * not-fired: just return (do not callout).
+ * One-shot: deactivate it.
+ * Clear: deactivate and clear the state.
+ * Dispatch: don't clear state, just deactivate it and mark it disabled.
+ * All others: just leave where they are.
+ */
+
+ if (result == 0) {
+ return (EJUSTRETURN);
+ } else if ((kn->kn_flags & EV_ONESHOT) != 0) {
+ knote_deactivate(kn);
+ if (kqlock2knotedrop(kq, kn)) {
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ }
+ } else if ((kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) != 0) {
+ if ((kn->kn_flags & EV_DISPATCH) != 0) {
+ /* deactivate and disable all dispatch knotes */
+ knote_deactivate(kn);
+ kn->kn_status |= KN_DISABLED;
+ } else if (!touch || kn->kn_fflags == 0) {
+ /* only deactivate if nothing since the touch */
+ knote_deactivate(kn);
+ }
+ if (!touch && (kn->kn_flags & EV_CLEAR) != 0) {
+ /* manually clear non-touch knotes */
+ kn->kn_data = 0;
+ kn->kn_fflags = 0;
+ }
+ kqunlock(kq);
+ } else {
+ /*
+ * leave on inprocess queue. We'll
+ * move all the remaining ones back
+ * the kq queue and wakeup any
+ * waiters when we are done.
+ */
+ kqunlock(kq);
+ }
+
+ /* callback to handle each event as we find it */
+ error = (callback)(kq, &kev, data);
+
+ kqlock(kq);
+ return (error);
+}
+
+/*
+ * Return 0 to indicate that processing should proceed,
+ * -1 if there is nothing to process.
+ *
+ * Called with kqueue locked and returns the same way,
+ * but may drop lock temporarily.
+ */
+static int
+kqueue_begin_processing(struct kqueue *kq)
+{
+ for (;;) {
+ if (kq->kq_count == 0) {
+ return (-1);
+ }
+
+ /* if someone else is processing the queue, wait */
+ if (kq->kq_nprocess != 0) {
+ wait_queue_assert_wait((wait_queue_t)kq->kq_wqs,
+ &kq->kq_nprocess, THREAD_UNINT, 0);
+ kq->kq_state |= KQ_PROCWAIT;
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ kqlock(kq);
+ } else {
+ kq->kq_nprocess = 1;
+ return (0);
+ }
+ }
+}
+
+/*
+ * Called with kqueue lock held.
+ */
+static void
+kqueue_end_processing(struct kqueue *kq)
+{
+ kq->kq_nprocess = 0;
+ if (kq->kq_state & KQ_PROCWAIT) {
+ kq->kq_state &= ~KQ_PROCWAIT;
+ wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs,
+ &kq->kq_nprocess, THREAD_AWAKENED);
+ }
+}
+
+/*
+ * kqueue_process - process the triggered events in a kqueue
+ *
+ * Walk the queued knotes and validate that they are
+ * really still triggered events by calling the filter
+ * routines (if necessary). Hold a use reference on
+ * the knote to avoid it being detached. For each event
+ * that is still considered triggered, invoke the
+ * callback routine provided.
+ *
+ * caller holds a reference on the kqueue.
+ * kqueue locked on entry and exit - but may be dropped
+ * kqueue list locked (held for duration of call)
+ */
+
+static int
+kqueue_process(struct kqueue *kq,
+ kevent_callback_t callback,
+ void *data,
+ int *countp,
+ struct proc *p)
+{
+ struct kqtailq inprocess;
+ struct knote *kn;
+ int nevents;
+ int error;
+
+ TAILQ_INIT(&inprocess);
+
+ if (kqueue_begin_processing(kq) == -1) {
+ *countp = 0;
+ /* Nothing to process */
+ return (0);
+ }
+
+ /*
+ * Clear any pre-posted status from previous runs, so we
+ * only detect events that occur during this run.
+ */
+ wait_queue_sub_clearrefs(kq->kq_wqs);
+
+ /*
+ * loop through the enqueued knotes, processing each one and
+ * revalidating those that need it. As they are processed,
+ * they get moved to the inprocess queue (so the loop can end).
+ */
+ error = 0;
+ nevents = 0;
+
+ while (error == 0 &&
+ (kn = TAILQ_FIRST(&kq->kq_head)) != NULL) {
+ error = knote_process(kn, callback, data, &inprocess, p);
+ if (error == EJUSTRETURN)
+ error = 0;
+ else
+ nevents++;
+ }
+
+ /*
+ * With the kqueue still locked, move any knotes
+ * remaining on the inprocess queue back to the
+ * kq's queue and wake up any waiters.
+ */
+ while ((kn = TAILQ_FIRST(&inprocess)) != NULL) {
+ assert(kn->kn_tq == &inprocess);
+ TAILQ_REMOVE(&inprocess, kn, kn_tqe);
+ kn->kn_tq = &kq->kq_head;
+ TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
+ }
+
+ kqueue_end_processing(kq);
+
+ *countp = nevents;
+ return (error);
+}
+
+
+static void
+kqueue_scan_continue(void *data, wait_result_t wait_result)
+{
+ thread_t self = current_thread();
+ uthread_t ut = (uthread_t)get_bsdthread_info(self);
+ struct _kqueue_scan * cont_args = &ut->uu_kevent.ss_kqueue_scan;
+ struct kqueue *kq = (struct kqueue *)data;
+ int error;
+ int count;
+
+ /* convert the (previous) wait_result to a proper error */
+ switch (wait_result) {
+ case THREAD_AWAKENED:
+ kqlock(kq);
+ error = kqueue_process(kq, cont_args->call, cont_args, &count,
+ current_proc());
+ if (error == 0 && count == 0) {
+ wait_queue_assert_wait((wait_queue_t)kq->kq_wqs,
+ KQ_EVENT, THREAD_ABORTSAFE, cont_args->deadline);
+ kq->kq_state |= KQ_SLEEP;
+ kqunlock(kq);
+ thread_block_parameter(kqueue_scan_continue, kq);
+ /* NOTREACHED */
+ }
+ kqunlock(kq);
+ break;
+ case THREAD_TIMED_OUT:
+ error = EWOULDBLOCK;
+ break;
+ case THREAD_INTERRUPTED:
+ error = EINTR;
+ break;
+ default:
+ panic("%s: - invalid wait_result (%d)", __func__,
+ wait_result);
+ error = 0;
+ }
+
+ /* call the continuation with the results */
+ assert(cont_args->cont != NULL);
+ (cont_args->cont)(kq, cont_args->data, error);
+}
+
+
+/*
+ * kqueue_scan - scan and wait for events in a kqueue
+ *
+ * Process the triggered events in a kqueue.
+ *
+ * If there are no events triggered arrange to
+ * wait for them. If the caller provided a
+ * continuation routine, then kevent_scan will
+ * also.
+ *
+ * The callback routine must be valid.
+ * The caller must hold a use-count reference on the kq.
+ */
+
+int
+kqueue_scan(struct kqueue *kq,
+ kevent_callback_t callback,
+ kqueue_continue_t continuation,
+ void *data,
+ struct timeval *atvp,
+ struct proc *p)
+{
+ thread_continue_t cont = THREAD_CONTINUE_NULL;
+ uint64_t deadline;
+ int error;
+ int first;
+
+ assert(callback != NULL);
+
+ first = 1;
+ for (;;) {
+ wait_result_t wait_result;
+ int count;
+
+ /*
+ * Make a pass through the kq to find events already
+ * triggered.
+ */
+ kqlock(kq);
+ error = kqueue_process(kq, callback, data, &count, p);
+ if (error || count)
+ break; /* lock still held */
+
+ /* looks like we have to consider blocking */
+ if (first) {
+ first = 0;
+ /* convert the timeout to a deadline once */
+ if (atvp->tv_sec || atvp->tv_usec) {
+ uint64_t now;
+
+ clock_get_uptime(&now);
+ nanoseconds_to_absolutetime((uint64_t)atvp->tv_sec * NSEC_PER_SEC +
+ atvp->tv_usec * (long)NSEC_PER_USEC,
+ &deadline);
+ if (now >= deadline) {
+ /* non-blocking call */
+ error = EWOULDBLOCK;
+ break; /* lock still held */
+ }
+ deadline -= now;
+ clock_absolutetime_interval_to_deadline(deadline, &deadline);
+ } else {
+ deadline = 0; /* block forever */
+ }
+
+ if (continuation) {
+ uthread_t ut = (uthread_t)get_bsdthread_info(current_thread());
+ struct _kqueue_scan *cont_args = &ut->uu_kevent.ss_kqueue_scan;
+
+ cont_args->call = callback;
+ cont_args->cont = continuation;
+ cont_args->deadline = deadline;
+ cont_args->data = data;
+ cont = kqueue_scan_continue;
+ }
+ }
+
+ /* go ahead and wait */
+ wait_queue_assert_wait_with_leeway((wait_queue_t)kq->kq_wqs,
+ KQ_EVENT, THREAD_ABORTSAFE, TIMEOUT_URGENCY_USER_NORMAL,
+ deadline, 0);
+ kq->kq_state |= KQ_SLEEP;
+ kqunlock(kq);
+ wait_result = thread_block_parameter(cont, kq);
+ /* NOTREACHED if (continuation != NULL) */
+
+ switch (wait_result) {
+ case THREAD_AWAKENED:
+ continue;
+ case THREAD_TIMED_OUT:
+ return (EWOULDBLOCK);
+ case THREAD_INTERRUPTED:
+ return (EINTR);
+ default:
+ panic("%s: - bad wait_result (%d)", __func__,
+ wait_result);
+ error = 0;
+ }
+ }
+ kqunlock(kq);
+ return (error);
+}
+
+
+/*
+ * XXX
+ * This could be expanded to call kqueue_scan, if desired.
+ */
+/*ARGSUSED*/
+static int
+kqueue_read(__unused struct fileproc *fp,
+ __unused struct uio *uio,
+ __unused int flags,
+ __unused vfs_context_t ctx)
+{
+ return (ENXIO);
+}
+
+/*ARGSUSED*/
+static int
+kqueue_write(__unused struct fileproc *fp,
+ __unused struct uio *uio,
+ __unused int flags,
+ __unused vfs_context_t ctx)
+{
+ return (ENXIO);
+}
+
+/*ARGSUSED*/
+static int
+kqueue_ioctl(__unused struct fileproc *fp,
+ __unused u_long com,
+ __unused caddr_t data,
+ __unused vfs_context_t ctx)
+{
+ return (ENOTTY);
+}
+
+/*ARGSUSED*/
+static int
+kqueue_select(struct fileproc *fp, int which, void *wql,
+ __unused vfs_context_t ctx)
+{
+ struct kqueue *kq = (struct kqueue *)fp->f_data;
+ struct knote *kn;
+ struct kqtailq inprocessq;
+ int retnum = 0;
+
+ if (which != FREAD)
+ return (0);
+
+ TAILQ_INIT(&inprocessq);
+
+ kqlock(kq);
+ /*
+ * If this is the first pass, link the wait queue associated with the
+ * the kqueue onto the wait queue set for the select(). Normally we
+ * use selrecord() for this, but it uses the wait queue within the
+ * selinfo structure and we need to use the main one for the kqueue to
+ * catch events from KN_STAYQUEUED sources. So we do the linkage manually.
+ * (The select() call will unlink them when it ends).
+ */
+ if (wql != NULL) {
+ thread_t cur_act = current_thread();
+ struct uthread * ut = get_bsdthread_info(cur_act);
+
+ kq->kq_state |= KQ_SEL;
+ wait_queue_link_noalloc((wait_queue_t)kq->kq_wqs, ut->uu_wqset,
+ (wait_queue_link_t)wql);
+ }
+
+ if (kqueue_begin_processing(kq) == -1) {
+ kqunlock(kq);
+ return (0);
+ }
+
+ if (kq->kq_count != 0) {
+ /*
+ * there is something queued - but it might be a
+ * KN_STAYQUEUED knote, which may or may not have
+ * any events pending. So, we have to walk the
+ * list of knotes to see, and peek at the stay-
+ * queued ones to be really sure.
+ */
+ while ((kn = (struct knote *)TAILQ_FIRST(&kq->kq_head)) != NULL) {
+ if ((kn->kn_status & KN_STAYQUEUED) == 0) {
+ retnum = 1;
+ goto out;
+ }
+
+ TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
+ TAILQ_INSERT_TAIL(&inprocessq, kn, kn_tqe);
+
+ if (kqlock2knoteuse(kq, kn)) {
+ unsigned peek;
+
+ peek = kn->kn_fop->f_peek(kn);
+ if (knoteuse2kqlock(kq, kn)) {
+ if (peek > 0) {
+ retnum = 1;
+ goto out;
+ }
+ } else {
+ retnum = 0;
+ }
+ }
+ }
+ }
+
+out:
+ /* Return knotes to active queue */
+ while ((kn = TAILQ_FIRST(&inprocessq)) != NULL) {
+ TAILQ_REMOVE(&inprocessq, kn, kn_tqe);
+ kn->kn_tq = &kq->kq_head;
+ TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
+ }
+
+ kqueue_end_processing(kq);
+ kqunlock(kq);
+ return (retnum);
+}
+
+/*
+ * kqueue_close -
+ */
+/*ARGSUSED*/
+static int
+kqueue_close(struct fileglob *fg, __unused vfs_context_t ctx)
+{
+ struct kqueue *kq = (struct kqueue *)fg->fg_data;
+
+ kqueue_dealloc(kq);
+ fg->fg_data = NULL;
+ return (0);
+}
+
+/*ARGSUSED*/
+/*
+ * The callers has taken a use-count reference on this kqueue and will donate it
+ * to the kqueue we are being added to. This keeps the kqueue from closing until
+ * that relationship is torn down.
+ */
+static int
+kqueue_kqfilter(__unused struct fileproc *fp, struct knote *kn, __unused vfs_context_t ctx)
+{
+ struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+ struct kqueue *parentkq = kn->kn_kq;
+
+ if (parentkq == kq ||
+ kn->kn_filter != EVFILT_READ)
+ return (1);
+
+ /*
+ * We have to avoid creating a cycle when nesting kqueues
+ * inside another. Rather than trying to walk the whole
+ * potential DAG of nested kqueues, we just use a simple
+ * ceiling protocol. When a kqueue is inserted into another,
+ * we check that the (future) parent is not already nested
+ * into another kqueue at a lower level than the potenial
+ * child (because it could indicate a cycle). If that test
+ * passes, we just mark the nesting levels accordingly.
+ */
+
+ kqlock(parentkq);
+ if (parentkq->kq_level > 0 &&
+ parentkq->kq_level < kq->kq_level)
+ {
+ kqunlock(parentkq);
+ return (1);
+ } else {
+ /* set parent level appropriately */
+ if (parentkq->kq_level == 0)
+ parentkq->kq_level = 2;
+ if (parentkq->kq_level < kq->kq_level + 1)
+ parentkq->kq_level = kq->kq_level + 1;
+ kqunlock(parentkq);
+
+ kn->kn_fop = &kqread_filtops;
+ kqlock(kq);
+ KNOTE_ATTACH(&kq->kq_sel.si_note, kn);
+ /* indicate nesting in child, if needed */
+ if (kq->kq_level == 0)
+ kq->kq_level = 1;
+ kqunlock(kq);
+ return (0);
+ }
+}
+
+/*
+ * kqueue_drain - called when kq is closed
+ */
+/*ARGSUSED*/
+static int
+kqueue_drain(struct fileproc *fp, __unused vfs_context_t ctx)
+{
+ struct kqueue *kq = (struct kqueue *)fp->f_fglob->fg_data;
+ kqlock(kq);
+ kqueue_wakeup(kq, 1);
+ kqunlock(kq);
+ return (0);
+}
+
+/*ARGSUSED*/
+int
+kqueue_stat(struct kqueue *kq, void *ub, int isstat64, proc_t p)
+{
+ kqlock(kq);
+ if (isstat64 != 0) {
+ struct stat64 *sb64 = (struct stat64 *)ub;
+
+ bzero((void *)sb64, sizeof(*sb64));
+ sb64->st_size = kq->kq_count;
+ if (kq->kq_state & KQ_KEV64)
+ sb64->st_blksize = sizeof(struct kevent64_s);
+ else
+ sb64->st_blksize = IS_64BIT_PROCESS(p) ? sizeof(struct user64_kevent) : sizeof(struct user32_kevent);
+ sb64->st_mode = S_IFIFO;
+ } else {
+ struct stat *sb = (struct stat *)ub;
+
+ bzero((void *)sb, sizeof(*sb));
+ sb->st_size = kq->kq_count;
+ if (kq->kq_state & KQ_KEV64)
+ sb->st_blksize = sizeof(struct kevent64_s);
+ else
+ sb->st_blksize = IS_64BIT_PROCESS(p) ? sizeof(struct user64_kevent) : sizeof(struct user32_kevent);
+ sb->st_mode = S_IFIFO;
+ }
+ kqunlock(kq);
+ return (0);
+}
+
+/*
+ * Called with the kqueue locked
+ */
+static void
+kqueue_wakeup(struct kqueue *kq, int closed)
+{
+ if ((kq->kq_state & (KQ_SLEEP | KQ_SEL)) != 0 || kq->kq_nprocess > 0) {
+ kq->kq_state &= ~(KQ_SLEEP | KQ_SEL);
+ wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, KQ_EVENT,
+ (closed) ? THREAD_INTERRUPTED : THREAD_AWAKENED);
+ }
+}
+
+void
+klist_init(struct klist *list)
+{
+ SLIST_INIT(list);
+}
+
+
+/*
+ * Query/Post each knote in the object's list
+ *
+ * The object lock protects the list. It is assumed
+ * that the filter/event routine for the object can
+ * determine that the object is already locked (via
+ * the hint) and not deadlock itself.
+ *
+ * The object lock should also hold off pending
+ * detach/drop operations. But we'll prevent it here
+ * too - just in case.
+ */
+void
+knote(struct klist *list, long hint)
+{
+ struct knote *kn;
+
+ SLIST_FOREACH(kn, list, kn_selnext) {
+ struct kqueue *kq = kn->kn_kq;
+
+ kqlock(kq);
+ if (kqlock2knoteuse(kq, kn)) {
+ int result;
+
+ /* call the event with only a use count */
+ result = kn->kn_fop->f_event(kn, hint);
+
+ /* if its not going away and triggered */
+ if (knoteuse2kqlock(kq, kn) && result)
+ knote_activate(kn, 1);
+ /* lock held again */
+ }
+ kqunlock(kq);
+ }
+}
+
+/*
+ * attach a knote to the specified list. Return true if this is the first entry.
+ * The list is protected by whatever lock the object it is associated with uses.
+ */
+int
+knote_attach(struct klist *list, struct knote *kn)
+{
+ int ret = SLIST_EMPTY(list);
+ SLIST_INSERT_HEAD(list, kn, kn_selnext);
+ return (ret);
+}
+
+/*
+ * detach a knote from the specified list. Return true if that was the last entry.
+ * The list is protected by whatever lock the object it is associated with uses.
+ */
+int
+knote_detach(struct klist *list, struct knote *kn)
+{
+ SLIST_REMOVE(list, kn, knote, kn_selnext);
+ return (SLIST_EMPTY(list));
+}
+
+/*
+ * For a given knote, link a provided wait queue directly with the kqueue.
+ * Wakeups will happen via recursive wait queue support. But nothing will move
+ * the knote to the active list at wakeup (nothing calls knote()). Instead,
+ * we permanently enqueue them here.
+ *
+ * kqueue and knote references are held by caller.
projects / apple / xnu.git / blobdiff