+#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 <string.h>
+#include <sys/proc_info.h>
+
+#include <kern/lock.h>
+#include <kern/clock.h>
+#include <kern/thread_call.h>
+#include <kern/sched_prim.h>
+#include <kern/zalloc.h>
+#include <kern/assert.h>
+
+#include <libkern/libkern.h>
+#include "kpi_mbuf_internal.h"
+
+MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
+
+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);
+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 *fp, vfs_context_t ctx);
+static int kqueue_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx);
+extern int kqueue_stat(struct fileproc *fp, void *ub, int isstat64, vfs_context_t ctx);
+
+static struct fileops kqueueops = {
+ kqueue_read,
+ kqueue_write,
+ kqueue_ioctl,
+ kqueue_select,
+ kqueue_close,
+ kqueue_kqfilter,
+ 0
+};
+
+static int kevent_copyin(user_addr_t *addrp, struct kevent *kevp, struct proc *p);
+static int kevent_copyout(struct kevent *kevp, user_addr_t *addrp, struct proc *p);
+
+static int kevent_callback(struct kqueue *kq, struct kevent *kevp, void *data);
+static void kevent_continue(struct kqueue *kq, void *data, int error);
+static void kevent_scan_continue(void *contp, wait_result_t wait_result);
+static int kevent_process(struct kqueue *kq, kevent_callback_t callback,
+ void *data, int *countp, 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);
+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 =
+ { 1, filt_fileattach, NULL, NULL };
+
+static void filt_kqdetach(struct knote *kn);
+static int filt_kqueue(struct knote *kn, long hint);
+static struct filterops kqread_filtops =
+ { 1, NULL, filt_kqdetach, filt_kqueue };
+
+/*
+ * placeholder for not-yet-implemented filters
+ */
+static int filt_badattach(struct knote *kn);
+static struct filterops bad_filtops =
+ { 0, filt_badattach, 0 , 0 };
+
+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 =
+ { 0, filt_procattach, filt_procdetach, filt_proc };
+
+extern struct filterops fs_filtops;
+
+extern struct filterops sig_filtops;
+
+
+/* Timer filter */
+static int filt_timercompute(struct knote *kn, uint64_t *abs_time);
+static void filt_timerexpire(void *knx, void *param1);
+static int filt_timerattach(struct knote *kn);
+static void filt_timerdetach(struct knote *kn);
+static int filt_timer(struct knote *kn, long hint);
+
+static struct filterops timer_filtops =
+ { 0, filt_timerattach, filt_timerdetach, filt_timer };
+
+/* to avoid arming timers that fire quicker than we can handle */
+static uint64_t filt_timerfloor = 0;
+
+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
+
+/*
+ * Table for 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 */
+ &bad_filtops, /* EVFILT_MACHPORT */
+ &fs_filtops /* EVFILT_FS */
+};
+
+/*
+ * 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.
+ *
+ * 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 (!kqlock2knoteuse(kq, kn)) {
+ kn->kn_status |= KN_DROPWAIT;
+ assert_wait(&kn->kn_status, THREAD_UNINT);
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ return 0;
+ }
+ 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) &&
+ (kn->kn_status & KN_USEWAIT)) {
+ kn->kn_status &= ~KN_USEWAIT;
+ thread_wakeup(&kn->kn_inuse);
+ }
+ return ((kn->kn_status & KN_DROPPING) == 0);
+ }
+
+/*
+ * Convert a kq lock to a knote drop referece.
+ *
+ * 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)
+{
+
+ if ((kn->kn_status & KN_DROPPING) == 0) {
+ kn->kn_status |= KN_DROPPING;
+ if (kn->kn_inuse > 0) {
+ kn->kn_status |= KN_USEWAIT;
+ assert_wait(&kn->kn_inuse, THREAD_UNINT);
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ } else
+ kqunlock(kq);
+ return 1;
+ } else {
+ kn->kn_status |= KN_DROPWAIT;
+ assert_wait(&kn->kn_status, THREAD_UNINT);
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ return 0;
+ }
+}
+
+/*
+ * 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) &&
+ (kn->kn_status & KN_USEWAIT)) {
+ kn->kn_status &= ~KN_USEWAIT;
+ thread_wakeup(&kn->kn_inuse);
+ }
+ 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_type f_fglob->fg_type
+#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);
+ }
+
+ 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)
+{
+ struct proc * p;
+
+ /* 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;
+
+ /*
+ * if the user is interested in this event, record it.
+ */
+ if (kn->kn_sfflags & event)
+ kn->kn_fflags |= event;
+
+ /*
+ * If this is the last possible event for the
+ * knote, unlink this knote from the process
+ * before the process goes away.
+ */
+ if (event == NOTE_REAP || (event == NOTE_EXIT && !(kn->kn_sfflags & NOTE_REAP))) {
+ kn->kn_flags |= (EV_EOF | EV_ONESHOT);
+ p = kn->kn_ptr.p_proc;
+ if (p != PROC_NULL) {
+ kn->kn_ptr.p_proc = PROC_NULL;
+ KNOTE_DETACH(&p->p_klist, kn);
+ }
+ return (1);
+ }
+
+ }
+
+ /* atomic check, no locking need when called from above */
+ return (kn->kn_fflags != 0);
+}
+
+/*
+ * filt_timercompute - compute absolute timeout
+ *
+ * The saved-data field in the knote contains the
+ * time value. The saved filter-flags indicates
+ * the unit of measurement.
+ *
+ * If the timeout is not absolute, adjust it for
+ * the current time.
+ */
+static int
+filt_timercompute(struct knote *kn, uint64_t *abs_time)
+{
+ uint64_t multiplier;
+ uint64_t raw;
+
+ 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;
+ }
+ nanoseconds_to_absolutetime((uint64_t)kn->kn_sdata * multiplier, &raw);
+ if (raw <= filt_timerfloor) {
+ *abs_time = 0;
+ return 0;
+ }
+ if ((kn->kn_sfflags & NOTE_ABSOLUTE) == NOTE_ABSOLUTE) {
+ uint32_t seconds, nanoseconds;
+ uint64_t now;
+
+ clock_get_calendar_nanotime(&seconds, &nanoseconds);
+ nanoseconds_to_absolutetime((uint64_t)seconds * NSEC_PER_SEC + nanoseconds,
+ &now);
+ if (now >= raw + filt_timerfloor) {
+ *abs_time = 0;
+ return 0;
+ }
+ raw -= now;
+ }
+ clock_absolutetime_interval_to_deadline(raw, abs_time);
+ return 0;
+}
+
+/*
+ * 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;
+
+ /* no "object" for timers, so fake a list */
+ SLIST_INIT(&timer_list);
+ SLIST_INSERT_HEAD(&timer_list, kn, kn_selnext);
+ KNOTE(&timer_list, 1);
+}
+
+/*
+ * data contains amount of time to sleep, in milliseconds,
+ * or a pointer to a timespec structure.
+ */
+static int
+filt_timerattach(struct knote *kn)
+{
+ thread_call_t callout;
+ uint64_t deadline;
+ int error;
+
+ error = filt_timercompute(kn, &deadline);
+ if (error)
+ return (error);
+
+ if (deadline) {
+ callout = thread_call_allocate(filt_timerexpire, kn);
+ if (NULL == callout)
+ return (ENOMEM);
+ } else {
+ /* handle as immediate */
+ kn->kn_sdata = 0;
+ callout = NULL;
+ }
+
+ filt_timerlock();
+ kn->kn_hook = (caddr_t)callout;
+
+ /* absolute=EV_ONESHOT */
+ if (kn->kn_sfflags & NOTE_ABSOLUTE)
+ kn->kn_flags |= EV_ONESHOT;
+
+ if (deadline) {
+ /* all others - if not faking immediate */
+ kn->kn_flags |= EV_CLEAR;
+ thread_call_enter_delayed(callout, deadline);
+ kn->kn_hookid = 0;
+ } else {
+ /* fake immediate */
+ kn->kn_hookid = 1;
+ }
+ filt_timerunlock();
+ return (0);
+}
+
+static void
+filt_timerdetach(struct knote *kn)
+{
+ thread_call_t callout;
+
+ filt_timerlock();
+ callout = (thread_call_t)kn->kn_hook;
+ if (callout != NULL) {
+ boolean_t cancelled;
+
+ /* cancel the callout if we can */
+ cancelled = thread_call_cancel(callout);
+ if (cancelled) {
+ /* got it, just free it */
+ kn->kn_hook = NULL;
+ filt_timerunlock();
+ thread_call_free(callout);
+ return;
+ }
+ /* we have to wait for the expire routine. */
+ kn->kn_hookid = -1; /* we are detaching */
+ assert_wait(&kn->kn_hook, THREAD_UNINT);
+ filt_timerunlock();
+ thread_block(THREAD_CONTINUE_NULL);
+ assert(kn->kn_hook == NULL);
+ return;
+ }
+ /* nothing to do */
+ filt_timerunlock();
+}
+
+
+
+static int
+filt_timer(struct knote *kn, __unused long hint)
+{
+ int result;
+
+ if (hint) {
+ /* real timer pop */
+ thread_call_t callout;
+ boolean_t detaching;
+
+ filt_timerlock();
+
+ kn->kn_data++;
+
+ detaching = (kn->kn_hookid < 0);
+ callout = (thread_call_t)kn->kn_hook;
+
+ if (!detaching && (kn->kn_flags & EV_ONESHOT) == 0) {
+ uint64_t deadline;
+ int error;
+
+ /* user input data may have changed - deal */
+ error = filt_timercompute(kn, &deadline);
+ if (error) {
+ kn->kn_flags |= EV_ERROR;
+ kn->kn_data = error;
+ } else if (deadline == 0) {
+ /* revert to fake immediate */
+ kn->kn_flags &= ~EV_CLEAR;
+ kn->kn_sdata = 0;
+ kn->kn_hookid = 1;
+ } else {
+ /* keep the callout and re-arm */
+ thread_call_enter_delayed(callout, deadline);
+ filt_timerunlock();
+ return 1;
+ }
+ }
+ kn->kn_hook = NULL;
+ filt_timerunlock();
+ thread_call_free(callout);
+
+ /* if someone is waiting for timer to pop */
+ if (detaching)
+ thread_wakeup(&kn->kn_hook);
+
+ return 1;
+ }
+
+ /* user-query */
+ filt_timerlock();
+
+ /* change fake timer to real if needed */
+ while (kn->kn_hookid > 0 && kn->kn_sdata > 0) {
+ int error;
+
+ /* update the fake timer (make real) */
+ kn->kn_hookid = 0;
+ kn->kn_data = 0;
+ filt_timerunlock();
+ error = filt_timerattach(kn);
+ filt_timerlock();
+ if (error) {
+ kn->kn_flags |= EV_ERROR;
+ kn->kn_data = error;
+ filt_timerunlock();
+ return 1;
+ }
+ }
+
+ /* if still fake, pretend it fired */
+ if (kn->kn_hookid > 0)
+ kn->kn_data = 1;
+
+ result = (kn->kn_data != 0);
+ filt_timerunlock();
+ return result;
+}
+
+static void
+filt_timerlock(void)
+{
+ lck_mtx_lock(&_filt_timerlock);
+}
+
+static void
+filt_timerunlock(void)
+{
+ lck_mtx_unlock(&_filt_timerlock);
+}
+
+/*
+ * 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) {
+ bzero(kq, sizeof(struct kqueue));
+ lck_spin_init(&kq->kq_lock, kq_lck_grp, kq_lck_attr);
+ TAILQ_INIT(&kq->kq_head);
+ TAILQ_INIT(&kq->kq_inprocess);
+ kq->kq_p = p;
+ }
+
+ 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);
+ lck_spin_destroy(&kq->kq_lock, kq_lck_grp);
+ FREE_ZONE(kq, sizeof(struct kqueue), M_KQUEUE);
+}
+
+int
+kqueue(struct proc *p, __unused struct kqueue_args *uap, register_t *retval)
+{
+ struct kqueue *kq;
+ struct fileproc *fp;
+ int fd, error;
+
+ error = falloc(p, &fp, &fd, vfs_context_current());
+ 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_type = DTYPE_KQUEUE;
+ fp->f_ops = &kqueueops;
+ fp->f_data = (caddr_t)kq;
+
+ proc_fdlock(p);
+ procfdtbl_releasefd(p, fd, NULL);
+ fp_drop(p, fd, fp, 1);
+ proc_fdunlock(p);
+
+ *retval = fd;
+ return (error);
+}
+
+int
+kqueue_portset_np(__unused struct proc *p,
+ __unused struct kqueue_portset_np_args *uap,
+ __unused register_t *retval)
+{
+ /* JMM - Placeholder for now */
+ return (ENOTSUP);
+}
+
+int
+kqueue_from_portset_np(__unused struct proc *p,
+ __unused struct kqueue_from_portset_np_args *uap,
+ __unused register_t *retval)
+{
+ /* JMM - Placeholder for now */
+ return (ENOTSUP);
+}
+
+static int
+kevent_copyin(user_addr_t *addrp, struct kevent *kevp, struct proc *p)
+{
+ int advance;
+ int error;
+
+ if (IS_64BIT_PROCESS(p)) {
+ struct user_kevent kev64;
+
+ advance = sizeof(kev64);
+ error = copyin(*addrp, (caddr_t)&kev64, advance);
+ if (error)
+ return error;
+ kevp->ident = CAST_DOWN(uintptr_t, kev64.ident);
+ kevp->filter = kev64.filter;
+ kevp->flags = kev64.flags;
+ kevp->fflags = kev64.fflags;
+ kevp->data = CAST_DOWN(intptr_t, kev64.data);
+ kevp->udata = kev64.udata;
+ } else {
+ /*
+ * compensate for legacy in-kernel kevent layout
+ * where the udata field is alredy 64-bit.
+ */
+ advance = sizeof(*kevp) + sizeof(void *) - sizeof(user_addr_t);
+ error = copyin(*addrp, (caddr_t)kevp, advance);
+ }
+ if (!error)
+ *addrp += advance;
+ return error;
+}
+
+static int
+kevent_copyout(struct kevent *kevp, user_addr_t *addrp, struct proc *p)
+{
+ int advance;
+ int error;
+
+ if (IS_64BIT_PROCESS(p)) {
+ struct user_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 {
+ /*
+ * compensate for legacy in-kernel kevent layout
+ * where the udata field is alredy 64-bit.
+ */
+ advance = sizeof(*kevp) + sizeof(void *) - sizeof(user_addr_t);
+ error = copyout((caddr_t)kevp, *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;
+ register_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, register_t *retval)
+{
+ user_addr_t changelist = uap->changelist;
+ user_addr_t ueventlist = uap->eventlist;
+ int nchanges = uap->nchanges;
+ int nevents = uap->nevents;
+ int fd = uap->fd;
+
+ struct _kevent *cont_args;
+ uthread_t ut;
+ struct kqueue *kq;
+ struct fileproc *fp;
+ struct kevent kev;
+ int error, noutputs;
+ struct timeval atv;
+
+ /* convert timeout to absolute - if we have one */
+ if (uap->timeout != USER_ADDR_NULL) {
+ struct timeval rtv;
+ if ( IS_64BIT_PROCESS(p) ) {
+ struct user_timespec ts;
+ error = copyin( uap->timeout, &ts, sizeof(ts) );
+ if ((ts.tv_sec & 0xFFFFFFFF00000000ull) != 0)
+ error = EINVAL;
+ else
+ TIMESPEC_TO_TIMEVAL(&rtv, &ts);
+ } else {
+ struct timespec ts;
+ error = copyin( uap->timeout, &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);
+
+ /* register all the change requests the user provided... */
+ noutputs = 0;
+ while (nchanges > 0 && error == 0) {
+ error = kevent_copyin(&changelist, &kev, p);
+ 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);
+ if (error == 0) {
+ nevents--;
+ noutputs++;
+ }
+ }
+ nchanges--;
+ }
+
+ /* store the continuation/completion data in the uthread */
+ ut = (uthread_t)get_bsdthread_info(current_thread());
+ cont_args = (struct _kevent *)&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;
+
+ if (nevents > 0 && noutputs == 0 && error == 0)
+ error = kevent_scan(kq, kevent_callback,
+ kevent_continue, cont_args,
+ &atv, p);
+ kevent_continue(kq, cont_args, error);
+ /* NOTREACHED */
+ 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 kevent *kevp, void *data)
+{
+ struct _kevent *cont_args;
+ int error;
+
+ cont_args = (struct _kevent *)data;
+ assert(cont_args->eventout < cont_args->eventcount);
+
+ /*
+ * Copy out the appropriate amount of event data for this user.
+ */
+ error = kevent_copyout(kevp, &cont_args->eventlist, current_proc());
+
+ /*
+ * 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_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 kevent *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);
+ }
+
+ /* this iocount needs to be dropped if it is not registered */
+ if (fops->f_isfd && (error = fp_lookup(p, kev->ident, &fp, 0)) != 0)
+ return(error);
+
+ restart:
+ proc_fdlock(p);
+ 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 = 0;
+
+ /* 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;
+
+ /*
+ * If the attach fails here, we can drop it knowing
+ * that nobody else has a reference to the knote.
+ */
+ if ((error = fops->f_attach(kn)) != 0) {
+ knote_drop(kn, p);
+ goto done;
+ }
+ } 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);
+ }
+
+ /*
+ * 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.
+ */
+ if (!kqlock2knoteusewait(kq, kn))
+ /* kqueue unlocked */
+ goto restart;
+
+ /*
+ * 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_sfflags = kev->fflags;
+ kn->kn_sdata = kev->data;
+ kn->kn_kevent.udata = kev->udata;
+ }
+
+ /* still have use ref on knote */
+ if (kn->kn_fop->f_event(kn, 0)) {
+ if (knoteuse2kqlock(kq, kn))
+ knote_activate(kn);
+ kqunlock(kq);
+ } else {
+ knote_put(kn);
+ }
+
+done:
+ if (fp != NULL)
+ fp_drop(p, kev->ident, fp, 0);
+ return (error);
+}
+
+/*
+ * kevent_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
+ */
+
+static int
+kevent_process(struct kqueue *kq,
+ kevent_callback_t callback,
+ void *data,
+ int *countp,
+ struct proc *p)
+{
+ struct knote *kn;
+ struct kevent kev;
+ int nevents;
+ int error;
+
+ restart:
+ if (kq->kq_count == 0) {
+ *countp = 0;
+ return 0;
+ }
+
+ /* if someone else is processing the queue, wait */
+ if (!TAILQ_EMPTY(&kq->kq_inprocess)) {
+ assert_wait(&kq->kq_inprocess, THREAD_UNINT);
+ kq->kq_state |= KQ_PROCWAIT;
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ kqlock(kq);
+ goto restart;
+ }
+
+ error = 0;
+ nevents = 0;
+ while (error == 0 &&
+ (kn = TAILQ_FIRST(&kq->kq_head)) != NULL) {
+
+ /*
+ * Take note off the active queue.
+ *
+ * Non-EV_ONESHOT events must be re-validated.
+ *
+ * Convert our lock to a use-count and call the event's
+ * filter routine to update.
+ *
+ * If the event is valid, or triggered while the kq
+ * is unlocked, move to the inprocess queue for processing.
+ */
+
+ if ((kn->kn_flags & EV_ONESHOT) == 0) {
+ int result;
+ knote_deactivate(kn);
+
+ if (kqlock2knoteuse(kq, kn)) {
+
+ /* call the filter with just a ref */
+ result = kn->kn_fop->f_event(kn, 0);
+
+ /* if it's still alive, make sure it's active */
+ if (knoteuse2kqlock(kq, kn) && result) {
+ /* may have been reactivated in filter*/
+ if (!(kn->kn_status & KN_ACTIVE)) {
+ knote_activate(kn);
+ }
+ } else {
+ continue;
+ }
+ } else {
+ continue;
+ }
+ }
+
+ /* knote is active: move onto inprocess queue */
+ assert(kn->kn_tq == &kq->kq_head);
+ TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
+ kn->kn_tq = &kq->kq_inprocess;
+ TAILQ_INSERT_TAIL(&kq->kq_inprocess, kn, kn_tqe);
+
+ /*
+ * Got a valid triggered knote with the kqueue
+ * still locked. Snapshot the data, and determine
+ * how to dispatch the knote for future events.
+ */
+ kev = kn->kn_kevent;
+
+ /* now what happens to it? */
+ if (kn->kn_flags & EV_ONESHOT) {
+ knote_deactivate(kn);
+ if (kqlock2knotedrop(kq, kn)) {
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ }
+ } else if (kn->kn_flags & EV_CLEAR) {
+ knote_deactivate(kn);
+ kn->kn_data = 0;
+ kn->kn_fflags = 0;
+ kqunlock(kq);
+ } else {
+ /*
+ * leave on in-process 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);
+ nevents++;
+
+ kqlock(kq);
+ }
+
+ /*
+ * With the kqueue still locked, move any knotes
+ * remaining on the in-process queue back to the
+ * kq's queue and wake up any waiters.
+ */
+ while ((kn = TAILQ_FIRST(&kq->kq_inprocess)) != NULL) {
+ assert(kn->kn_tq == &kq->kq_inprocess);
+ TAILQ_REMOVE(&kq->kq_inprocess, kn, kn_tqe);
+ kn->kn_tq = &kq->kq_head;
+ TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
+ }
+ if (kq->kq_state & KQ_PROCWAIT) {
+ kq->kq_state &= ~KQ_PROCWAIT;
+ thread_wakeup(&kq->kq_inprocess);
+ }
+
+ *countp = nevents;
+ return error;
+}
+
+
+static void
+kevent_scan_continue(void *data, wait_result_t wait_result)
+{
+ uthread_t ut = (uthread_t)get_bsdthread_info(current_thread());
+ struct _kevent_scan * cont_args = &ut->uu_kevent.ss_kevent_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 = kevent_process(kq, cont_args->call, cont_args, &count, current_proc());
+ if (error == 0 && count == 0) {
+ assert_wait_deadline(kq, THREAD_ABORTSAFE, cont_args->deadline);
+ kq->kq_state |= KQ_SLEEP;
+ kqunlock(kq);
+ thread_block_parameter(kevent_scan_continue, kq);
+ /* NOTREACHED */
+ }
+ kqunlock(kq);
+ break;
+ case THREAD_TIMED_OUT:
+ error = EWOULDBLOCK;
+ break;
+ case THREAD_INTERRUPTED:
+ error = EINTR;
+ break;
+ default:
+ panic("kevent_scan_cont() - invalid wait_result (%d)", wait_result);
+ error = 0;
+ }
+
+ /* call the continuation with the results */
+ assert(cont_args->cont != NULL);
+ (cont_args->cont)(kq, cont_args->data, error);
+}
+
+
+/*
+ * kevent_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
+kevent_scan(struct kqueue *kq,
+ kevent_callback_t callback,
+ kevent_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 = kevent_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 * 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 _kevent_scan *cont_args = &ut->uu_kevent.ss_kevent_scan;
+
+ cont_args->call = callback;
+ cont_args->cont = continuation;
+ cont_args->deadline = deadline;
+ cont_args->data = data;
+ cont = kevent_scan_continue;
+ }
+ }
+
+ /* go ahead and wait */
+ assert_wait_deadline(kq, THREAD_ABORTSAFE, deadline);
+ 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("kevent_scan - bad wait_result (%d)",
+ 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, vfs_context_t ctx)
+{
+ struct kqueue *kq = (struct kqueue *)fp->f_data;
+ int retnum = 0;
+
+ if (which == FREAD) {
+ kqlock(kq);
+ if (kq->kq_count) {
+ retnum = 1;
+ } else {
+ selrecord(vfs_context_proc(ctx), &kq->kq_sel, wql);
+ kq->kq_state |= KQ_SEL;
+ }
+ 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);
+ }
+}
+
+/*ARGSUSED*/
+int
+kqueue_stat(struct fileproc *fp, void *ub, int isstat64, __unused vfs_context_t ctx)
+{
+ struct stat *sb = (struct stat *)0; /* warning avoidance ; protected by isstat64 */
+ struct stat64 * sb64 = (struct stat64 *)0; /* warning avoidance ; protected by isstat64 */
+
+ struct kqueue *kq = (struct kqueue *)fp->f_data;
+ if (isstat64 != 0) {
+ sb64 = (struct stat64 *)ub;
+ bzero((void *)sb64, sizeof(*sb64));
+ sb64->st_size = kq->kq_count;
+ sb64->st_blksize = sizeof(struct kevent);
+ sb64->st_mode = S_IFIFO;
+ } else {
+ sb = (struct stat *)ub;
+ bzero((void *)sb, sizeof(*sb));
+ sb->st_size = kq->kq_count;
+ sb->st_blksize = sizeof(struct kevent);
+ sb->st_mode = S_IFIFO;
+ }
+
+ return (0);
+}
+
+/*
+ * Called with the kqueue locked
+ */
+static void
+kqueue_wakeup(struct kqueue *kq)
+{
+
+ if (kq->kq_state & KQ_SLEEP) {
+ kq->kq_state &= ~KQ_SLEEP;
+ thread_wakeup(kq);
+ }
+ if (kq->kq_state & KQ_SEL) {
+ kq->kq_state &= ~KQ_SEL;
+ selwakeup(&kq->kq_sel);
+ }
+ KNOTE(&kq->kq_sel.si_note, 0);
+}
+
+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 hind) 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);
+ /* 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);
+}
+
+/*
+ * remove all knotes referencing a specified fd
+ *
+ * Essentially an inlined knote_remove & knote_drop
+ * when we know for sure that the thing is a file
+ *
+ * Entered with the proc_fd lock already held.
+ * It returns the same way, but may drop it temporarily.
+ */
+void
+knote_fdclose(struct proc *p, int fd)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct klist *list;
+ struct knote *kn;
+
+ list = &fdp->fd_knlist[fd];
+ while ((kn = SLIST_FIRST(list)) != NULL) {
+ struct kqueue *kq = kn->kn_kq;
+
+ if (kq->kq_p != p)
+ panic("knote_fdclose: proc mismatch (kq->kq_p=%p != p=%p)", kq->kq_p, p);
+
+ kqlock(kq);
+ proc_fdunlock(p);
+
+ /*
+ * Convert the lock to a drop ref.
+ * If we get it, go ahead and drop it.
+ * Otherwise, we waited for it to
+ * be dropped by the other guy, so
+ * it is safe to move on in the list.
+ */
+ if (kqlock2knotedrop(kq, kn)) {
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, p);
+ }
+
+ proc_fdlock(p);
+
+ /* the fd tables may have changed - start over */
+ list = &fdp->fd_knlist[fd];
+ }
+}
+
+/* proc_fdlock held on entry (and exit) */
+static int
+knote_fdpattach(struct knote *kn, struct filedesc *fdp, __unused struct proc *p)
+{
+ struct klist *list = NULL;
+
+ if (! kn->kn_fop->f_isfd) {
+ if (fdp->fd_knhashmask == 0)
+ fdp->fd_knhash = hashinit(CONFIG_KN_HASHSIZE, M_KQUEUE,
+ &fdp->fd_knhashmask);
+ list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
+ } else {
+ if ((u_int)fdp->fd_knlistsize <= kn->kn_id) {
+ u_int size = 0;
+
+ /* have to grow the fd_knlist */
+ size = fdp->fd_knlistsize;
+ while (size <= kn->kn_id)
+ size += KQEXTENT;
+ MALLOC(list, struct klist *,
+ size * sizeof(struct klist *), M_KQUEUE, M_WAITOK);
+ if (list == NULL)
+ return (ENOMEM);
+
+ bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list,
+ fdp->fd_knlistsize * sizeof(struct klist *));
+ bzero((caddr_t)list +
+ fdp->fd_knlistsize * sizeof(struct klist *),
+ (size - fdp->fd_knlistsize) * sizeof(struct klist *));
+ FREE(fdp->fd_knlist, M_KQUEUE);
+ fdp->fd_knlist = list;
+ fdp->fd_knlistsize = size;
+ }
+ list = &fdp->fd_knlist[kn->kn_id];
+ }
+ SLIST_INSERT_HEAD(list, kn, kn_link);
+ return (0);
+}
+
+
+
+/*
+ * should be called at spl == 0, since we don't want to hold spl
+ * while calling fdrop and free.
+ */
+static void
+knote_drop(struct knote *kn, __unused struct proc *ctxp)
+{
+ struct kqueue *kq = kn->kn_kq;
+ struct proc *p = kq->kq_p;
+ struct filedesc *fdp = p->p_fd;
+ struct klist *list;
+
+ proc_fdlock(p);
+ if (kn->kn_fop->f_isfd)
+ list = &fdp->fd_knlist[kn->kn_id];
+ else
+ list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
+
+ SLIST_REMOVE(list, kn, knote, kn_link);
+ kqlock(kq);
+ knote_dequeue(kn);
+ if (kn->kn_status & KN_DROPWAIT)
+ thread_wakeup(&kn->kn_status);
+ kqunlock(kq);
+ proc_fdunlock(p);
+
+ if (kn->kn_fop->f_isfd)
+ fp_drop(p, kn->kn_id, kn->kn_fp, 0);
+
+ knote_free(kn);
+}
+
+/* called with kqueue lock held */
+static void
+knote_activate(struct knote *kn)
+{
+ struct kqueue *kq = kn->kn_kq;
+
+ kn->kn_status |= KN_ACTIVE;
+ knote_enqueue(kn);
+ kqueue_wakeup(kq);
+ }
+
+/* called with kqueue lock held */
+static void
+knote_deactivate(struct knote *kn)
+{
+ kn->kn_status &= ~KN_ACTIVE;
+ knote_dequeue(kn);
+}
+
+/* called with kqueue lock held */
+static void
+knote_enqueue(struct knote *kn)
+{
+ struct kqueue *kq = kn->kn_kq;
+
+ if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) {
+ struct kqtailq *tq = kn->kn_tq;
+
+ TAILQ_INSERT_TAIL(tq, kn, kn_tqe);
+ kn->kn_status |= KN_QUEUED;
+ kq->kq_count++;
+ }
+}
+
+/* called with kqueue lock held */
+static void
+knote_dequeue(struct knote *kn)
+{
+ struct kqueue *kq = kn->kn_kq;
+
+ //assert((kn->kn_status & KN_DISABLED) == 0);
+ if ((kn->kn_status & KN_QUEUED) == KN_QUEUED) {
+ struct kqtailq *tq = kn->kn_tq;
+
+ TAILQ_REMOVE(tq, kn, kn_tqe);
+ kn->kn_tq = &kq->kq_head;
+ kn->kn_status &= ~KN_QUEUED;
+ kq->kq_count--;
+ }
+}
+
+void
+knote_init(void)
+{
+ knote_zone = zinit(sizeof(struct knote), 8192*sizeof(struct knote), 8192, "knote zone");
+
+ /* allocate kq lock group attribute and group */
+ kq_lck_grp_attr= lck_grp_attr_alloc_init();
+
+ kq_lck_grp = lck_grp_alloc_init("kqueue", kq_lck_grp_attr);
+
+ /* Allocate kq lock attribute */
+ kq_lck_attr = lck_attr_alloc_init();
+
+ /* Initialize the timer filter lock */
+ lck_mtx_init(&_filt_timerlock, kq_lck_grp, kq_lck_attr);
+}
+SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL)
+
+static struct knote *
+knote_alloc(void)
+{
+ return ((struct knote *)zalloc(knote_zone));
+}
+
+static void
+knote_free(struct knote *kn)
+{
+ zfree(knote_zone, kn);
+}
+
+#if SOCKETS
projects / apple / xnu.git / blobdiff