/* * Copyright (c) 2000-2013 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * 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 * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "net/net_str_id.h" #include #if VM_PRESSURE_EVENTS #include #endif #if CONFIG_MEMORYSTATUS #include #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); extern int kqueue_stat(struct fileproc *fp, void *ub, int isstat64, 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_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 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 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_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); } } 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 fileproc *fp, void *ub, int isstat64, __unused vfs_context_t ctx) { struct kqueue *kq = (struct kqueue *)fp->f_data; 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 = sizeof(struct 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 = sizeof(struct kevent); sb->st_mode = S_IFIFO; } 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. * * caller provides the wait queue link structure. */ int knote_link_wait_queue(struct knote *kn, struct wait_queue *wq, wait_queue_link_t wql) { struct kqueue *kq = kn->kn_kq; kern_return_t kr; kr = wait_queue_link_noalloc(wq, kq->kq_wqs, wql); if (kr == KERN_SUCCESS) { knote_markstayqueued(kn); return (0); } else { return (EINVAL); } } /* * Unlink the provided wait queue from the kqueue associated with a knote. * Also remove it from the magic list of directly attached knotes. * * Note that the unlink may have already happened from the other side, so * ignore any failures to unlink and just remove it from the kqueue list. * * On success, caller is responsible for the link structure */ int knote_unlink_wait_queue(struct knote *kn, struct wait_queue *wq, wait_queue_link_t *wqlp) { struct kqueue *kq = kn->kn_kq; kern_return_t kr; kr = wait_queue_unlink_nofree(wq, kq->kq_wqs, wqlp); kqlock(kq); kn->kn_status &= ~KN_STAYQUEUED; knote_dequeue(kn); kqunlock(kq); return ((kr != KERN_SUCCESS) ? EINVAL : 0); } /* * 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("%s: proc mismatch (kq->kq_p=%p != p=%p)", __func__, 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, 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; if (kn->kn_id >= (uint64_t)p->p_rlimit[RLIMIT_NOFILE].rlim_cur || kn->kn_id >= (uint64_t)maxfiles) return (EINVAL); /* have to grow the fd_knlist */ size = fdp->fd_knlistsize; while (size <= kn->kn_id) size += KQEXTENT; if (size >= (UINT_MAX/sizeof(struct klist *))) return (EINVAL); 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; int needswakeup; 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); needswakeup = (kn->kn_status & KN_USEWAIT); kqunlock(kq); proc_fdunlock(p); if (needswakeup) wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, &kn->kn_status, THREAD_AWAKENED); 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, int propagate) { struct kqueue *kq = kn->kn_kq; kn->kn_status |= KN_ACTIVE; knote_enqueue(kn); kqueue_wakeup(kq, 0); /* this is a real event: wake up the parent kq, too */ if (propagate) KNOTE(&kq->kq_sel.si_note, 0); } /* 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) { if ((kn->kn_status & (KN_QUEUED | KN_STAYQUEUED)) == KN_STAYQUEUED || (kn->kn_status & (KN_QUEUED | KN_STAYQUEUED | KN_DISABLED)) == 0) { struct kqtailq *tq = kn->kn_tq; struct kqueue *kq = kn->kn_kq; 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; if ((kn->kn_status & (KN_QUEUED | KN_STAYQUEUED)) == 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); #if VM_PRESSURE_EVENTS /* Initialize the vm pressure list lock */ vm_pressure_init(kq_lck_grp, kq_lck_attr); #endif #if CONFIG_MEMORYSTATUS /* Initialize the memorystatus list lock */ memorystatus_kevent_init(kq_lck_grp, kq_lck_attr); #endif } 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 #include #include #include #include #include #include #include #include #include static lck_grp_attr_t *kev_lck_grp_attr; static lck_attr_t *kev_lck_attr; static lck_grp_t *kev_lck_grp; static decl_lck_rw_data(,kev_lck_data); static lck_rw_t *kev_rwlock = &kev_lck_data; static int kev_attach(struct socket *so, int proto, struct proc *p); static int kev_detach(struct socket *so); static int kev_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp, struct proc *p); static lck_mtx_t * event_getlock(struct socket *, int); static int event_lock(struct socket *, int, void *); static int event_unlock(struct socket *, int, void *); static int event_sofreelastref(struct socket *); static void kev_delete(struct kern_event_pcb *); static struct pr_usrreqs event_usrreqs = { .pru_attach = kev_attach, .pru_control = kev_control, .pru_detach = kev_detach, .pru_soreceive = soreceive, }; static struct protosw eventsw[] = { { .pr_type = SOCK_RAW, .pr_protocol = SYSPROTO_EVENT, .pr_flags = PR_ATOMIC, .pr_usrreqs = &event_usrreqs, .pr_lock = event_lock, .pr_unlock = event_unlock, .pr_getlock = event_getlock, } }; static lck_mtx_t * event_getlock(struct socket *so, int locktype) { #pragma unused(locktype) struct kern_event_pcb *ev_pcb = (struct kern_event_pcb *)so->so_pcb; if (so->so_pcb != NULL) { if (so->so_usecount < 0) panic("%s: so=%p usecount=%d lrh= %s\n", __func__, so, so->so_usecount, solockhistory_nr(so)); /* NOTREACHED */ } else { panic("%s: so=%p NULL NO so_pcb %s\n", __func__, so, solockhistory_nr(so)); /* NOTREACHED */ } return (&ev_pcb->evp_mtx); } static int event_lock(struct socket *so, int refcount, void *lr) { void *lr_saved; if (lr == NULL) lr_saved = __builtin_return_address(0); else lr_saved = lr; if (so->so_pcb != NULL) { lck_mtx_lock(&((struct kern_event_pcb *)so->so_pcb)->evp_mtx); } else { panic("%s: so=%p NO PCB! lr=%p lrh= %s\n", __func__, so, lr_saved, solockhistory_nr(so)); /* NOTREACHED */ } if (so->so_usecount < 0) { panic("%s: so=%p so_pcb=%p lr=%p ref=%d lrh= %s\n", __func__, so, so->so_pcb, lr_saved, so->so_usecount, solockhistory_nr(so)); /* NOTREACHED */ } if (refcount) so->so_usecount++; so->lock_lr[so->next_lock_lr] = lr_saved; so->next_lock_lr = (so->next_lock_lr+1) % SO_LCKDBG_MAX; return (0); } static int event_unlock(struct socket *so, int refcount, void *lr) { void *lr_saved; lck_mtx_t *mutex_held; if (lr == NULL) lr_saved = __builtin_return_address(0); else lr_saved = lr; if (refcount) so->so_usecount--; if (so->so_usecount < 0) { panic("%s: so=%p usecount=%d lrh= %s\n", __func__, so, so->so_usecount, solockhistory_nr(so)); /* NOTREACHED */ } if (so->so_pcb == NULL) { panic("%s: so=%p NO PCB usecount=%d lr=%p lrh= %s\n", __func__, so, so->so_usecount, (void *)lr_saved, solockhistory_nr(so)); /* NOTREACHED */ } mutex_held = (&((struct kern_event_pcb *)so->so_pcb)->evp_mtx); lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED); so->unlock_lr[so->next_unlock_lr] = lr_saved; so->next_unlock_lr = (so->next_unlock_lr+1) % SO_LCKDBG_MAX; if (so->so_usecount == 0) { VERIFY(so->so_flags & SOF_PCBCLEARING); event_sofreelastref(so); } else { lck_mtx_unlock(mutex_held); } return (0); } static int event_sofreelastref(struct socket *so) { struct kern_event_pcb *ev_pcb = (struct kern_event_pcb *)so->so_pcb; lck_mtx_assert(&(ev_pcb->evp_mtx), LCK_MTX_ASSERT_OWNED); so->so_pcb = NULL; /* * Disable upcall in the event another thread is in kev_post_msg() * appending record to the receive socket buffer, since sbwakeup() * may release the socket lock otherwise. */ so->so_rcv.sb_flags &= ~SB_UPCALL; so->so_snd.sb_flags &= ~SB_UPCALL; so->so_event = NULL; lck_mtx_unlock(&(ev_pcb->evp_mtx)); lck_mtx_assert(&(ev_pcb->evp_mtx), LCK_MTX_ASSERT_NOTOWNED); lck_rw_lock_exclusive(kev_rwlock); LIST_REMOVE(ev_pcb, evp_link); lck_rw_done(kev_rwlock); kev_delete(ev_pcb); sofreelastref(so, 1); return (0); } static int event_proto_count = (sizeof (eventsw) / sizeof (struct protosw)); static struct kern_event_head kern_event_head; static u_int32_t static_event_id = 0; #define EVPCB_ZONE_MAX 65536 #define EVPCB_ZONE_NAME "kerneventpcb" static struct zone *ev_pcb_zone; /* * Install the protosw's for the NKE manager. Invoked at extension load time */ void kern_event_init(struct domain *dp) { struct protosw *pr; int i; VERIFY(!(dp->dom_flags & DOM_INITIALIZED)); VERIFY(dp == systemdomain); kev_lck_grp_attr = lck_grp_attr_alloc_init(); if (kev_lck_grp_attr == NULL) { panic("%s: lck_grp_attr_alloc_init failed\n", __func__); /* NOTREACHED */ } kev_lck_grp = lck_grp_alloc_init("Kernel Event Protocol", kev_lck_grp_attr); if (kev_lck_grp == NULL) { panic("%s: lck_grp_alloc_init failed\n", __func__); /* NOTREACHED */ } kev_lck_attr = lck_attr_alloc_init(); if (kev_lck_attr == NULL) { panic("%s: lck_attr_alloc_init failed\n", __func__); /* NOTREACHED */ } lck_rw_init(kev_rwlock, kev_lck_grp, kev_lck_attr); if (kev_rwlock == NULL) { panic("%s: lck_mtx_alloc_init failed\n", __func__); /* NOTREACHED */ } for (i = 0, pr = &eventsw[0]; i < event_proto_count; i++, pr++) net_add_proto(pr, dp, 1); ev_pcb_zone = zinit(sizeof(struct kern_event_pcb), EVPCB_ZONE_MAX * sizeof(struct kern_event_pcb), 0, EVPCB_ZONE_NAME); if (ev_pcb_zone == NULL) { panic("%s: failed allocating ev_pcb_zone", __func__); /* NOTREACHED */ } zone_change(ev_pcb_zone, Z_EXPAND, TRUE); zone_change(ev_pcb_zone, Z_CALLERACCT, TRUE); } static int kev_attach(struct socket *so, __unused int proto, __unused struct proc *p) { int error = 0; struct kern_event_pcb *ev_pcb; error = soreserve(so, KEV_SNDSPACE, KEV_RECVSPACE); if (error != 0) return (error); if ((ev_pcb = (struct kern_event_pcb *)zalloc(ev_pcb_zone)) == NULL) { return (ENOBUFS); } bzero(ev_pcb, sizeof(struct kern_event_pcb)); lck_mtx_init(&ev_pcb->evp_mtx, kev_lck_grp, kev_lck_attr); ev_pcb->evp_socket = so; ev_pcb->evp_vendor_code_filter = 0xffffffff; so->so_pcb = (caddr_t) ev_pcb; lck_rw_lock_exclusive(kev_rwlock); LIST_INSERT_HEAD(&kern_event_head, ev_pcb, evp_link); lck_rw_done(kev_rwlock); return (error); } static void kev_delete(struct kern_event_pcb *ev_pcb) { VERIFY(ev_pcb != NULL); lck_mtx_destroy(&ev_pcb->evp_mtx, kev_lck_grp); zfree(ev_pcb_zone, ev_pcb); } static int kev_detach(struct socket *so) { struct kern_event_pcb *ev_pcb = (struct kern_event_pcb *) so->so_pcb; if (ev_pcb != NULL) { soisdisconnected(so); so->so_flags |= SOF_PCBCLEARING; } return (0); } /* * For now, kev_vendor_code and mbuf_tags use the same * mechanism. */ errno_t kev_vendor_code_find( const char *string, u_int32_t *out_vendor_code) { if (strlen(string) >= KEV_VENDOR_CODE_MAX_STR_LEN) { return (EINVAL); } return (net_str_id_find_internal(string, out_vendor_code, NSI_VENDOR_CODE, 1)); } errno_t kev_msg_post(struct kev_msg *event_msg) { mbuf_tag_id_t min_vendor, max_vendor; net_str_id_first_last(&min_vendor, &max_vendor, NSI_VENDOR_CODE); if (event_msg == NULL) return (EINVAL); /* * Limit third parties to posting events for registered vendor codes * only */ if (event_msg->vendor_code < min_vendor || event_msg->vendor_code > max_vendor) return (EINVAL); return (kev_post_msg(event_msg)); } int kev_post_msg(struct kev_msg *event_msg) { struct mbuf *m, *m2; struct kern_event_pcb *ev_pcb; struct kern_event_msg *ev; char *tmp; u_int32_t total_size; int i; /* Verify the message is small enough to fit in one mbuf w/o cluster */ total_size = KEV_MSG_HEADER_SIZE; for (i = 0; i < 5; i++) { if (event_msg->dv[i].data_length == 0) break; total_size += event_msg->dv[i].data_length; } if (total_size > MLEN) { return (EMSGSIZE); } m = m_get(M_DONTWAIT, MT_DATA); if (m == 0) return (ENOBUFS); ev = mtod(m, struct kern_event_msg *); total_size = KEV_MSG_HEADER_SIZE; tmp = (char *) &ev->event_data[0]; for (i = 0; i < 5; i++) { if (event_msg->dv[i].data_length == 0) break; total_size += event_msg->dv[i].data_length; bcopy(event_msg->dv[i].data_ptr, tmp, event_msg->dv[i].data_length); tmp += event_msg->dv[i].data_length; } ev->id = ++static_event_id; ev->total_size = total_size; ev->vendor_code = event_msg->vendor_code; ev->kev_class = event_msg->kev_class; ev->kev_subclass = event_msg->kev_subclass; ev->event_code = event_msg->event_code; m->m_len = total_size; lck_rw_lock_shared(kev_rwlock); for (ev_pcb = LIST_FIRST(&kern_event_head); ev_pcb; ev_pcb = LIST_NEXT(ev_pcb, evp_link)) { lck_mtx_lock(&ev_pcb->evp_mtx); if (ev_pcb->evp_socket->so_pcb == NULL) { lck_mtx_unlock(&ev_pcb->evp_mtx); continue; } if (ev_pcb->evp_vendor_code_filter != KEV_ANY_VENDOR) { if (ev_pcb->evp_vendor_code_filter != ev->vendor_code) { lck_mtx_unlock(&ev_pcb->evp_mtx); continue; } if (ev_pcb->evp_class_filter != KEV_ANY_CLASS) { if (ev_pcb->evp_class_filter != ev->kev_class) { lck_mtx_unlock(&ev_pcb->evp_mtx); continue; } if ((ev_pcb->evp_subclass_filter != KEV_ANY_SUBCLASS) && (ev_pcb->evp_subclass_filter != ev->kev_subclass)) { lck_mtx_unlock(&ev_pcb->evp_mtx); continue; } } } m2 = m_copym(m, 0, m->m_len, M_NOWAIT); if (m2 == 0) { m_free(m); lck_mtx_unlock(&ev_pcb->evp_mtx); lck_rw_done(kev_rwlock); return (ENOBUFS); } if (sbappendrecord(&ev_pcb->evp_socket->so_rcv, m2)) sorwakeup(ev_pcb->evp_socket); lck_mtx_unlock(&ev_pcb->evp_mtx); } m_free(m); lck_rw_done(kev_rwlock); return (0); } static int kev_control(struct socket *so, u_long cmd, caddr_t data, __unused struct ifnet *ifp, __unused struct proc *p) { struct kev_request *kev_req = (struct kev_request *) data; struct kern_event_pcb *ev_pcb; struct kev_vendor_code *kev_vendor; u_int32_t *id_value = (u_int32_t *) data; switch (cmd) { case SIOCGKEVID: *id_value = static_event_id; break; case SIOCSKEVFILT: ev_pcb = (struct kern_event_pcb *) so->so_pcb; ev_pcb->evp_vendor_code_filter = kev_req->vendor_code; ev_pcb->evp_class_filter = kev_req->kev_class; ev_pcb->evp_subclass_filter = kev_req->kev_subclass; break; case SIOCGKEVFILT: ev_pcb = (struct kern_event_pcb *) so->so_pcb; kev_req->vendor_code = ev_pcb->evp_vendor_code_filter; kev_req->kev_class = ev_pcb->evp_class_filter; kev_req->kev_subclass = ev_pcb->evp_subclass_filter; break; case SIOCGKEVVENDOR: kev_vendor = (struct kev_vendor_code *)data; /* Make sure string is NULL terminated */ kev_vendor->vendor_string[KEV_VENDOR_CODE_MAX_STR_LEN-1] = 0; return (net_str_id_find_internal(kev_vendor->vendor_string, &kev_vendor->vendor_code, NSI_VENDOR_CODE, 0)); default: return (ENOTSUP); } return (0); } #endif /* SOCKETS */ int fill_kqueueinfo(struct kqueue *kq, struct kqueue_info * kinfo) { struct vinfo_stat * st; /* No need for the funnel as fd is kept alive */ st = &kinfo->kq_stat; st->vst_size = kq->kq_count; if (kq->kq_state & KQ_KEV64) st->vst_blksize = sizeof(struct kevent64_s); else st->vst_blksize = sizeof(struct kevent); st->vst_mode = S_IFIFO; if (kq->kq_state & KQ_SEL) kinfo->kq_state |= PROC_KQUEUE_SELECT; if (kq->kq_state & KQ_SLEEP) kinfo->kq_state |= PROC_KQUEUE_SLEEP; return (0); } void knote_markstayqueued(struct knote *kn) { kqlock(kn->kn_kq); kn->kn_status |= KN_STAYQUEUED; knote_enqueue(kn); kqunlock(kn->kn_kq); }