/*
- * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2017 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
- *
* 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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
+ * 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,
* 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_LICENSE_HEADER_END@
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*
*/
/*-
/*
* @(#)kern_event.c 1.0 (3/31/2000)
*/
+#include <stdint.h>
+#include <machine/atomic.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
-#include <sys/proc.h>
-#include <sys/malloc.h>
+#include <sys/proc_internal.h>
+#include <sys/kauth.h>
+#include <sys/malloc.h>
#include <sys/unistd.h>
-#include <sys/file.h>
+#include <sys/file_internal.h>
#include <sys/fcntl.h>
#include <sys/select.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
-
+#include <sys/sysproto.h>
+#include <sys/user.h>
+#include <sys/vnode_internal.h>
+#include <string.h>
+#include <sys/proc_info.h>
+#include <sys/codesign.h>
+#include <sys/pthread_shims.h>
+#include <sys/kdebug.h>
+#include <sys/reason.h>
+#include <os/reason_private.h>
+#include <pexpert/pexpert.h>
+
+#include <kern/locks.h>
+#include <kern/clock.h>
+#include <kern/cpu_data.h>
+#include <kern/policy_internal.h>
+#include <kern/thread_call.h>
+#include <kern/sched_prim.h>
+#include <kern/waitq.h>
#include <kern/zalloc.h>
+#include <kern/kalloc.h>
+#include <kern/assert.h>
+#include <kern/ast.h>
+#include <kern/thread.h>
+#include <kern/kcdata.h>
-MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
+#include <pthread/priority_private.h>
+#include <pthread/workqueue_syscalls.h>
+#include <pthread/workqueue_internal.h>
+#include <libkern/libkern.h>
+#include <libkern/OSAtomic.h>
-static int kqueue_scan(struct file *fp, int maxevents,
- struct kevent *ulistp, const struct timespec *timeout,
- register_t *retval, struct proc *p);
-static void kqueue_wakeup(struct kqueue *kq);
-
-static int kqueue_read __P((struct file *fp, struct uio *uio,
- struct ucred *cred, int flags, struct proc *p));
-static int kqueue_write __P((struct file *fp, struct uio *uio,
- struct ucred *cred, int flags, struct proc *p));
-static int kqueue_ioctl __P((struct file *fp, u_long com, caddr_t data,
- struct proc *p));
-static int kqueue_select __P((struct file *fp, int which, void *wql,
- struct proc *p));
-static int kqueue_close __P((struct file *fp, struct proc *p));
-static int kqueue_kqfilter __P((struct file *fp, struct knote *kn, struct proc *p));
-
-static struct fileops kqueueops = {
- kqueue_read,
- kqueue_write,
- kqueue_ioctl,
- kqueue_select,
- kqueue_close,
- kqueue_kqfilter
-};
+#include "net/net_str_id.h"
-static void knote_fdpattach(struct knote *kn, struct filedesc *fdp);
-static void knote_drop(struct knote *kn, struct proc *p);
-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);
+#include <mach/task.h>
+#include <libkern/section_keywords.h>
-static int filt_fileattach(struct knote *kn);
-static struct filterops file_filtops =
- { 1, filt_fileattach, NULL, NULL };
+#if CONFIG_MEMORYSTATUS
+#include <sys/kern_memorystatus.h>
+#endif
-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 };
+extern thread_t port_name_to_thread(mach_port_name_t port_name); /* osfmk/kern/ipc_tt.h */
+extern mach_port_name_t ipc_entry_name_mask(mach_port_name_t name); /* osfmk/ipc/ipc_entry.h */
-/*
- * JMM - placeholder for not-yet-implemented filters
- */
-static int filt_badattach(struct knote *kn);
-static struct filterops bad_filtops =
- { 0, filt_badattach, 0 , 0 };
+#define KEV_EVTID(code) BSDDBG_CODE(DBG_BSD_KEVENT, (code))
-static int filt_procattach(struct knote *kn);
-static void filt_procdetach(struct knote *kn);
-static int filt_proc(struct knote *kn, long hint);
+MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system");
-static struct filterops proc_filtops =
- { 0, filt_procattach, filt_procdetach, filt_proc };
+#define KQ_EVENT NO_EVENT64
+
+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 *wq_link_id,
+ 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,
+ struct kevent_internal_s *kev, vfs_context_t ctx);
+static int kqueue_drain(struct fileproc *fp, vfs_context_t ctx);
+
+static const struct fileops kqueueops = {
+ .fo_type = DTYPE_KQUEUE,
+ .fo_read = kqueue_read,
+ .fo_write = kqueue_write,
+ .fo_ioctl = kqueue_ioctl,
+ .fo_select = kqueue_select,
+ .fo_close = kqueue_close,
+ .fo_kqfilter = kqueue_kqfilter,
+ .fo_drain = kqueue_drain,
+};
-extern struct filterops fs_filtops;
+static void kevent_put_kq(struct proc *p, kqueue_id_t id, struct fileproc *fp, struct kqueue *kq);
+static int kevent_internal(struct proc *p,
+ kqueue_id_t id, kqueue_id_t *id_out,
+ user_addr_t changelist, int nchanges,
+ user_addr_t eventlist, int nevents,
+ user_addr_t data_out, uint64_t data_available,
+ unsigned int flags, user_addr_t utimeout,
+ kqueue_continue_t continuation,
+ int32_t *retval);
+static int kevent_copyin(user_addr_t *addrp, struct kevent_internal_s *kevp,
+ struct proc *p, unsigned int flags);
+static int kevent_copyout(struct kevent_internal_s *kevp, user_addr_t *addrp,
+ struct proc *p, unsigned int flags);
+char * kevent_description(struct kevent_internal_s *kevp, char *s, size_t n);
+
+static int kevent_register_wait_prepare(struct knote *kn, struct kevent_internal_s *kev);
+static void kevent_register_wait_block(struct turnstile *ts, thread_t handoff_thread,
+ struct knote_lock_ctx *knlc, thread_continue_t cont,
+ struct _kevent_register *cont_args) __dead2;
+static void kevent_register_wait_return(struct _kevent_register *cont_args) __dead2;
+static void kevent_register_wait_cleanup(struct knote *kn);
+static inline void kqueue_release_last(struct proc *p, kqueue_t kqu);
+static void kqueue_interrupt(struct kqueue *kq);
+static int kevent_callback(struct kqueue *kq, struct kevent_internal_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 *callback_data,
+ struct filt_process_s *process_data, int *countp);
+static int kqueue_queue_empty(struct kqueue *kq, kq_index_t qos_index);
+
+static struct kqtailq *kqueue_get_suppressed_queue(kqueue_t kq, struct knote *kn);
+static void kqueue_threadreq_initiate(struct kqueue *kq, struct kqrequest *kqr, kq_index_t qos, int flags);
+
+static void kqworkq_update_override(struct kqworkq *kqwq, struct knote *kn, kq_index_t qos);
+static void kqworkq_unbind(proc_t p, struct kqrequest *kqr);
+static thread_qos_t kqworkq_unbind_locked(struct kqworkq *kqwq, struct kqrequest *kqr, thread_t thread);
+static struct kqrequest *kqworkq_get_request(struct kqworkq *kqwq, kq_index_t qos_index);
+
+static void kqworkloop_update_override(struct kqworkloop *kqwl, kq_index_t override_index);
+static void kqworkloop_unbind(proc_t p, struct kqworkloop *kwql);
+static thread_qos_t kqworkloop_unbind_locked(struct kqworkloop *kwql, thread_t thread);
+static kq_index_t kqworkloop_owner_override(struct kqworkloop *kqwl);
+enum {
+ KQWL_UTQ_NONE,
+ /*
+ * The wakeup qos is the qos of QUEUED knotes.
+ *
+ * This QoS is accounted for with the events override in the
+ * kqr_override_index field. It is raised each time a new knote is queued at
+ * a given QoS. The kqr_wakeup_indexes field is a superset of the non empty
+ * knote buckets and is recomputed after each event delivery.
+ */
+ KQWL_UTQ_UPDATE_WAKEUP_QOS,
+ KQWL_UTQ_UPDATE_STAYACTIVE_QOS,
+ KQWL_UTQ_RECOMPUTE_WAKEUP_QOS,
+ KQWL_UTQ_UNBINDING, /* attempt to rebind */
+ KQWL_UTQ_PARKING,
+ /*
+ * The wakeup override is for suppressed knotes that have fired again at
+ * a higher QoS than the one for which they are suppressed already.
+ * This override is cleared when the knote suppressed list becomes empty.
+ */
+ KQWL_UTQ_UPDATE_WAKEUP_OVERRIDE,
+ KQWL_UTQ_RESET_WAKEUP_OVERRIDE,
+ /*
+ * The QoS is the maximum QoS of an event enqueued on this workloop in
+ * userland. It is copied from the only EVFILT_WORKLOOP knote with
+ * a NOTE_WL_THREAD_REQUEST bit set allowed on this workloop. If there is no
+ * such knote, this QoS is 0.
+ */
+ KQWL_UTQ_SET_QOS_INDEX,
+ KQWL_UTQ_REDRIVE_EVENTS,
+};
+static void kqworkloop_update_threads_qos(struct kqworkloop *kqwl, int op, kq_index_t qos);
+static void kqworkloop_request_help(struct kqworkloop *kqwl, kq_index_t qos_index);
+static int kqworkloop_end_processing(struct kqworkloop *kqwl, int flags, int kevent_flags);
+
+static int knote_process(struct knote *kn, kevent_callback_t callback, void *callback_data,
+ struct filt_process_s *process_data);
+
+static int kq_add_knote(struct kqueue *kq, struct knote *kn,
+ struct knote_lock_ctx *knlc, struct proc *p);
+static struct knote *kq_find_knote_and_kq_lock(struct kqueue *kq, struct kevent_internal_s *kev, bool is_fd, struct proc *p);
+
+static void knote_drop(struct kqueue *kq, struct knote *kn, struct knote_lock_ctx *knlc);
+static struct knote *knote_alloc(void);
+static void knote_free(struct knote *kn);
+
+static void knote_activate(struct knote *kn);
+static void knote_deactivate(struct knote *kn);
+
+static void knote_enable(struct knote *kn);
+static void knote_disable(struct knote *kn);
+
+static int knote_enqueue(struct knote *kn);
+static void knote_dequeue(struct knote *kn);
+
+static void knote_suppress(struct knote *kn);
+static void knote_unsuppress(struct knote *kn);
+static void knote_wakeup(struct knote *kn);
+
+static bool knote_should_apply_qos_override(struct kqueue *kq, struct knote *kn,
+ int result, thread_qos_t *qos_out);
+static void knote_apply_qos_override(struct knote *kn, kq_index_t qos_index);
+static void knote_adjust_qos(struct kqueue *kq, struct knote *kn, int result);
+static void knote_reset_priority(struct knote *kn, pthread_priority_t pp);
+static kq_index_t knote_get_qos_override_index(struct knote *kn);
+static void knote_set_qos_overcommit(struct knote *kn);
+
+static zone_t knote_zone;
+static zone_t kqfile_zone;
+static zone_t kqworkq_zone;
+static zone_t kqworkloop_zone;
+#if DEVELOPMENT || DEBUG
+#define KEVENT_PANIC_ON_WORKLOOP_OWNERSHIP_LEAK (1U << 0)
+#define KEVENT_PANIC_ON_NON_ENQUEUED_PROCESS (1U << 1)
+#define KEVENT_PANIC_BOOT_ARG_INITIALIZED (1U << 31)
+
+#define KEVENT_PANIC_DEFAULT_VALUE (0)
+static uint32_t
+kevent_debug_flags(void)
+{
+ static uint32_t flags = KEVENT_PANIC_DEFAULT_VALUE;
-extern struct filterops sig_filtops;
+ if ((flags & KEVENT_PANIC_BOOT_ARG_INITIALIZED) == 0) {
+ uint32_t value = 0;
+ if (!PE_parse_boot_argn("kevent_debug", &value, sizeof(value))) {
+ value = KEVENT_PANIC_DEFAULT_VALUE;
+ }
+ value |= KEVENT_PANIC_BOOT_ARG_INITIALIZED;
+ os_atomic_store(&flags, value, relaxed);
+ }
+ return flags;
+}
+#endif
-#if 0
-/* JMM - We don't implement these now */
-static void filt_timerexpire(void *knx);
-static int filt_timerattach(struct knote *kn);
-static void filt_timerdetach(struct knote *kn);
-static int filt_timer(struct knote *kn, long hint);
+#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
-static struct filterops timer_filtops =
- { 0, filt_timerattach, filt_timerdetach, filt_timer };
+/* placeholder for not-yet-implemented filters */
+static int filt_badattach(struct knote *kn, struct kevent_internal_s *kev);
+static int filt_badevent(struct knote *kn, long hint);
+SECURITY_READ_ONLY_EARLY(static struct filterops) bad_filtops = {
+ .f_attach = filt_badattach,
+};
-static int kq_ncallouts = 0;
-static int kq_calloutmax = (4 * 1024);
+#if CONFIG_MEMORYSTATUS
+extern const struct filterops memorystatus_filtops;
+#endif /* CONFIG_MEMORYSTATUS */
+extern const struct filterops fs_filtops;
+extern const struct filterops sig_filtops;
+extern const struct filterops machport_filtops;
+extern const struct filterops pipe_rfiltops;
+extern const struct filterops pipe_wfiltops;
+extern const struct filterops ptsd_kqops;
+extern const struct filterops ptmx_kqops;
+extern const struct filterops soread_filtops;
+extern const struct filterops sowrite_filtops;
+extern const struct filterops sock_filtops;
+extern const struct filterops soexcept_filtops;
+extern const struct filterops spec_filtops;
+extern const struct filterops bpfread_filtops;
+extern const struct filterops necp_fd_rfiltops;
+extern const struct filterops fsevent_filtops;
+extern const struct filterops vnode_filtops;
+extern const struct filterops tty_filtops;
+
+const static struct filterops file_filtops;
+const static struct filterops kqread_filtops;
+const static struct filterops proc_filtops;
+const static struct filterops timer_filtops;
+const static struct filterops user_filtops;
+const static struct filterops workloop_filtops;
-SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
- &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
-#endif /* 0 */
+/*
+ *
+ * Rules for adding new filters to the system:
+ * Public filters:
+ * - Add a new "EVFILT_" option value to bsd/sys/event.h (typically a negative value)
+ * in the exported section of the header
+ * - Update the EVFILT_SYSCOUNT value to reflect the new addition
+ * - Add a filterops to the sysfilt_ops array. Public filters should be added at the end
+ * of the Public Filters section in the array.
+ * Private filters:
+ * - Add a new "EVFILT_" value to bsd/sys/event.h (typically a positive value)
+ * in the XNU_KERNEL_PRIVATE section of the header
+ * - Update the EVFILTID_MAX value to reflect the new addition
+ * - Add a filterops to the sysfilt_ops. Private filters should be added at the end of
+ * the Private filters section of the array.
+ */
+SECURITY_READ_ONLY_EARLY(static struct filterops *) sysfilt_ops[EVFILTID_MAX] = {
+ /* Public Filters */
+ [~EVFILT_READ] = &file_filtops,
+ [~EVFILT_WRITE] = &file_filtops,
+ [~EVFILT_AIO] = &bad_filtops,
+ [~EVFILT_VNODE] = &file_filtops,
+ [~EVFILT_PROC] = &proc_filtops,
+ [~EVFILT_SIGNAL] = &sig_filtops,
+ [~EVFILT_TIMER] = &timer_filtops,
+ [~EVFILT_MACHPORT] = &machport_filtops,
+ [~EVFILT_FS] = &fs_filtops,
+ [~EVFILT_USER] = &user_filtops,
+ &bad_filtops,
+ [~EVFILT_VM] = &bad_filtops,
+ [~EVFILT_SOCK] = &file_filtops,
+#if CONFIG_MEMORYSTATUS
+ [~EVFILT_MEMORYSTATUS] = &memorystatus_filtops,
+#else
+ [~EVFILT_MEMORYSTATUS] = &bad_filtops,
+#endif
+ [~EVFILT_EXCEPT] = &file_filtops,
+ [~EVFILT_WORKLOOP] = &workloop_filtops,
+
+ /* Private filters */
+ [EVFILTID_KQREAD] = &kqread_filtops,
+ [EVFILTID_PIPE_R] = &pipe_rfiltops,
+ [EVFILTID_PIPE_W] = &pipe_wfiltops,
+ [EVFILTID_PTSD] = &ptsd_kqops,
+ [EVFILTID_SOREAD] = &soread_filtops,
+ [EVFILTID_SOWRITE] = &sowrite_filtops,
+ [EVFILTID_SCK] = &sock_filtops,
+ [EVFILTID_SOEXCEPT] = &soexcept_filtops,
+ [EVFILTID_SPEC] = &spec_filtops,
+ [EVFILTID_BPFREAD] = &bpfread_filtops,
+ [EVFILTID_NECP_FD] = &necp_fd_rfiltops,
+ [EVFILTID_FSEVENT] = &fsevent_filtops,
+ [EVFILTID_VN] = &vnode_filtops,
+ [EVFILTID_TTY] = &tty_filtops,
+ [EVFILTID_PTMX] = &ptmx_kqops,
+};
-static zone_t knote_zone;
+/* waitq prepost callback */
+void waitq_set__CALLING_PREPOST_HOOK__(void *kq_hook, void *knote_hook, int qos);
-#define KNOTE_ACTIVATE(kn) do { \
- kn->kn_status |= KN_ACTIVE; \
- if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
- knote_enqueue(kn); \
-} while(0)
+static inline struct kqworkloop *
+kqr_kqworkloop(struct kqrequest *kqr)
+{
+ if (kqr->kqr_state & KQR_WORKLOOP) {
+ return __container_of(kqr, struct kqworkloop, kqwl_request);
+ }
+ return NULL;
+}
-#define KN_HASHSIZE 64 /* XXX should be tunable */
-#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
+static inline kqueue_t
+kqr_kqueue(proc_t p, struct kqrequest *kqr)
+{
+ kqueue_t kqu;
+ if (kqr->kqr_state & KQR_WORKLOOP) {
+ kqu.kqwl = kqr_kqworkloop(kqr);
+ } else {
+ kqu.kqwq = (struct kqworkq *)p->p_fd->fd_wqkqueue;
+ assert(kqr >= kqu.kqwq->kqwq_request &&
+ kqr < kqu.kqwq->kqwq_request + KQWQ_NBUCKETS);
+ }
+ return kqu;
+}
-#if 0
-extern struct filterops aio_filtops;
-#endif
+static inline boolean_t
+is_workqueue_thread(thread_t thread)
+{
+ return (thread_get_tag(thread) & THREAD_TAG_WORKQUEUE);
+}
/*
- * Table for for all system-defined filters.
+ * kqueue/note lock implementations
+ *
+ * The kqueue lock guards the kq state, the state of its queues,
+ * and the kqueue-aware status and locks of individual knotes.
+ *
+ * The kqueue workq lock is used to protect state guarding the
+ * interaction of the kqueue with the workq. This state cannot
+ * be guarded by the kq lock - as it needs to be taken when we
+ * already have the waitq set lock held (during the waitq hook
+ * callback). It might be better to use the waitq lock itself
+ * for this, but the IRQ requirements make that difficult).
+ *
+ * Knote flags, filter flags, and associated data are protected
+ * by the underlying object lock - and are only ever looked at
+ * by calling the filter to get a [consistent] snapshot of that
+ * data.
*/
-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 */
-#if 0
- &timer_filtops, /* EVFILT_TIMER */
-#else
- &bad_filtops, /* EVFILT_TIMER */
-#endif
- &bad_filtops, /* EVFILT_MACHPORT */
- &fs_filtops /* EVFILT_FS */
-};
+static lck_grp_attr_t *kq_lck_grp_attr;
+static lck_grp_t *kq_lck_grp;
+static lck_attr_t *kq_lck_attr;
-static int
-filt_fileattach(struct knote *kn)
+static inline void
+kqlock(kqueue_t kqu)
{
-
- return (fo_kqfilter(kn->kn_fp, kn, current_proc()));
+ lck_spin_lock(&kqu.kq->kq_lock);
}
-static void
-filt_kqdetach(struct knote *kn)
+static inline void
+kqlock_held(__assert_only kqueue_t kqu)
{
- struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+ LCK_SPIN_ASSERT(&kqu.kq->kq_lock, LCK_ASSERT_OWNED);
+}
- if (kq->kq_state & KQ_SEL)
- return;
+static inline void
+kqunlock(kqueue_t kqu)
+{
+ lck_spin_unlock(&kqu.kq->kq_lock);
+}
- KNOTE_DETACH(&kq->kq_sel.si_note, kn);
+static inline void
+kq_req_lock(kqueue_t kqu)
+{
+ assert(kqu.kq->kq_state & (KQ_WORKLOOP | KQ_WORKQ));
+ lck_spin_lock(&kqu.kq->kq_reqlock);
}
-/*ARGSUSED*/
-static int
-filt_kqueue(struct knote *kn, long hint)
+static inline void
+kq_req_unlock(kqueue_t kqu)
{
- struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+ assert(kqu.kq->kq_state & (KQ_WORKLOOP | KQ_WORKQ));
+ lck_spin_unlock(&kqu.kq->kq_reqlock);
+}
- kn->kn_data = kq->kq_count;
- return (kn->kn_data > 0);
+static inline void
+kq_req_held(__assert_only kqueue_t kqu)
+{
+ assert(kqu.kq->kq_state & (KQ_WORKLOOP | KQ_WORKQ));
+ LCK_SPIN_ASSERT(&kqu.kq->kq_reqlock, LCK_ASSERT_OWNED);
}
-static int
-filt_procattach(struct knote *kn)
+static inline void
+knhash_lock(proc_t p)
{
- struct proc *p;
+ lck_mtx_lock(&p->p_fd->fd_knhashlock);
+}
- p = pfind(kn->kn_id);
- if (p == NULL)
- return (ESRCH);
- if (! PRISON_CHECK(current_proc(), p))
- return (EACCES);
+static inline void
+knhash_unlock(proc_t p)
+{
+ lck_mtx_unlock(&p->p_fd->fd_knhashlock);
+}
- kn->kn_ptr.p_proc = p;
- kn->kn_flags |= EV_CLEAR; /* automatically set */
+#pragma mark knote locks
- /*
- * internal flag indicating registration done by kernel
- */
- if (kn->kn_flags & EV_FLAG1) {
- kn->kn_data = kn->kn_sdata; /* ppid */
- kn->kn_fflags = NOTE_CHILD;
- kn->kn_flags &= ~EV_FLAG1;
+/*
+ * Enum used by the knote_lock_* functions.
+ *
+ * KNOTE_KQ_LOCK_ALWAYS
+ * The function will always return with the kq lock held.
+ *
+ * KNOTE_KQ_UNLOCK_ON_SUCCESS
+ * The function will return with the kq lock held if it was successful
+ * (knote_lock() is the only function that can fail).
+ *
+ * KNOTE_KQ_UNLOCK_ON_FAILURE
+ * The function will return with the kq lock held if it was unsuccessful
+ * (knote_lock() is the only function that can fail).
+ *
+ * KNOTE_KQ_UNLOCK:
+ * The function returns with the kq unlocked.
+ */
+#define KNOTE_KQ_LOCK_ALWAYS 0x0
+#define KNOTE_KQ_LOCK_ON_SUCCESS 0x1
+#define KNOTE_KQ_LOCK_ON_FAILURE 0x2
+#define KNOTE_KQ_UNLOCK 0x3
+
+#if DEBUG || DEVELOPMENT
+__attribute__((noinline, not_tail_called, disable_tail_calls))
+void knote_lock_ctx_chk(struct knote_lock_ctx *knlc)
+{
+ /* evil hackery to make sure no one forgets to unlock */
+ assert(knlc->knlc_state == KNOTE_LOCK_CTX_UNLOCKED);
+}
+#endif
+
+static struct knote_lock_ctx *
+knote_lock_ctx_find(struct kqueue *kq, struct knote *kn)
+{
+ struct knote_lock_ctx *ctx;
+ LIST_FOREACH(ctx, &kq->kq_knlocks, knlc_le) {
+ if (ctx->knlc_knote == kn) return ctx;
}
+ panic("knote lock context not found: %p", kn);
+ __builtin_trap();
+}
- /* XXX lock the proc here while adding to the list? */
- KNOTE_ATTACH(&p->p_klist, kn);
+/* slowpath of knote_lock() */
+__attribute__((noinline))
+static bool __result_use_check
+knote_lock_slow(struct kqueue *kq, struct knote *kn,
+ struct knote_lock_ctx *knlc, int kqlocking)
+{
+ kqlock_held(kq);
- return (0);
+ struct knote_lock_ctx *owner_lc = knote_lock_ctx_find(kq, kn);
+ thread_t owner_thread = owner_lc->knlc_thread;
+
+#if DEBUG || DEVELOPMENT
+ knlc->knlc_state = KNOTE_LOCK_CTX_WAITING;
+#endif
+
+ thread_reference(owner_thread);
+ TAILQ_INSERT_TAIL(&owner_lc->knlc_head, knlc, knlc_tqe);
+ assert_wait(&kn->kn_status, THREAD_UNINT | THREAD_WAIT_NOREPORT);
+ kqunlock(kq);
+
+ if (thread_handoff_deallocate(owner_thread) == THREAD_RESTART) {
+ if (kqlocking == KNOTE_KQ_LOCK_ALWAYS ||
+ kqlocking == KNOTE_KQ_LOCK_ON_FAILURE) {
+ kqlock(kq);
+ }
+#if DEBUG || DEVELOPMENT
+ assert(knlc->knlc_state == KNOTE_LOCK_CTX_WAITING);
+ knlc->knlc_state = KNOTE_LOCK_CTX_UNLOCKED;
+#endif
+ return false;
+ }
+#if DEBUG || DEVELOPMENT
+ assert(knlc->knlc_state == KNOTE_LOCK_CTX_LOCKED);
+#endif
+ if (kqlocking == KNOTE_KQ_LOCK_ALWAYS ||
+ kqlocking == KNOTE_KQ_LOCK_ON_SUCCESS) {
+ kqlock(kq);
+ }
+ return true;
}
/*
- * The knote may be attached to a different process, which may exit,
- * leaving nothing for the knote to be attached to. So when the process
- * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
- * it will be deleted when read out. However, as part of the knote deletion,
- * this routine is called, so a check is needed to avoid actually performing
- * a detach, because the original process does not exist any more.
+ * Attempts to take the "knote" lock.
+ *
+ * Called with the kqueue lock held.
+ *
+ * Returns true if the knote lock is acquired, false if it has been dropped
*/
-static void
-filt_procdetach(struct knote *kn)
+static bool __result_use_check
+knote_lock(struct kqueue *kq, struct knote *kn, struct knote_lock_ctx *knlc,
+ int kqlocking)
{
- struct proc *p = kn->kn_ptr.p_proc;
+ kqlock_held(kq);
- if (kn->kn_status & KN_DETACHED)
- return;
+#if DEBUG || DEVELOPMENT
+ assert(knlc->knlc_state == KNOTE_LOCK_CTX_UNLOCKED);
+#endif
+ knlc->knlc_knote = kn;
+ knlc->knlc_thread = current_thread();
+ TAILQ_INIT(&knlc->knlc_head);
+
+ if (__improbable(kn->kn_status & KN_LOCKED)) {
+ return knote_lock_slow(kq, kn, knlc, kqlocking);
+ }
+
+ /*
+ * When the knote will be dropped, the knote lock is taken before
+ * KN_DROPPING is set, and then the knote will be removed from any
+ * hash table that references it before the lock is canceled.
+ */
+ assert((kn->kn_status & KN_DROPPING) == 0);
+ LIST_INSERT_HEAD(&kq->kq_knlocks, knlc, knlc_le);
+ kn->kn_status |= KN_LOCKED;
+#if DEBUG || DEVELOPMENT
+ knlc->knlc_state = KNOTE_LOCK_CTX_LOCKED;
+#endif
- /* XXX locking? this might modify another process. */
- KNOTE_DETACH(&p->p_klist, kn);
+ if (kqlocking == KNOTE_KQ_UNLOCK ||
+ kqlocking == KNOTE_KQ_LOCK_ON_FAILURE) {
+ kqunlock(kq);
+ }
+ return true;
}
-static int
-filt_proc(struct knote *kn, long hint)
+/*
+ * Unlocks a knote successfully locked with knote_lock().
+ *
+ * Called with the kqueue lock held.
+ *
+ * Returns with the kqueue lock held according to KNOTE_KQ_* flags
+ */
+static void
+knote_unlock(struct kqueue *kq, struct knote *kn,
+ struct knote_lock_ctx *knlc, int flags)
{
- u_int event;
+ kqlock_held(kq);
- /*
- * mask off extra data
- */
- event = (u_int)hint & NOTE_PCTRLMASK;
+ assert(knlc->knlc_knote == kn);
+ assert(kn->kn_status & KN_LOCKED);
+#if DEBUG || DEVELOPMENT
+ assert(knlc->knlc_state == KNOTE_LOCK_CTX_LOCKED);
+#endif
- /*
- * if the user is interested in this event, record it.
- */
- if (kn->kn_sfflags & event)
- kn->kn_fflags |= event;
+ struct knote_lock_ctx *next_owner_lc = TAILQ_FIRST(&knlc->knlc_head);
- /*
- * process is gone, so flag the event as finished.
- */
- if (event == NOTE_EXIT) {
- kn->kn_status |= KN_DETACHED;
- kn->kn_flags |= (EV_EOF | EV_ONESHOT);
- return (1);
- }
+ LIST_REMOVE(knlc, knlc_le);
- /*
- * process forked, and user wants to track the new process,
- * so attach a new knote to it, and immediately report an
- * event with the parent's pid.
- */
- if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
- struct kevent kev;
- int error;
+ if (next_owner_lc) {
+ assert(next_owner_lc->knlc_knote == kn);
+ TAILQ_REMOVE(&knlc->knlc_head, next_owner_lc, knlc_tqe);
+ assert(TAILQ_EMPTY(&next_owner_lc->knlc_head));
+ TAILQ_CONCAT(&next_owner_lc->knlc_head, &knlc->knlc_head, knlc_tqe);
+ LIST_INSERT_HEAD(&kq->kq_knlocks, next_owner_lc, knlc_le);
+#if DEBUG || DEVELOPMENT
+ next_owner_lc->knlc_state = KNOTE_LOCK_CTX_LOCKED;
+#endif
+ } else {
+ kn->kn_status &= ~KN_LOCKED;
+ }
+ if (kn->kn_inuse == 0) {
/*
- * register knote with new process.
+ * No f_event() in flight anymore, we can leave QoS "Merge" mode
+ *
+ * See knote_should_apply_qos_override()
*/
- kev.ident = hint & NOTE_PDATAMASK; /* pid */
- kev.filter = kn->kn_filter;
- kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
- kev.fflags = kn->kn_sfflags;
- kev.data = kn->kn_id; /* parent */
- kev.udata = kn->kn_kevent.udata; /* preserve udata */
- error = kqueue_register(kn->kn_kq, &kev, NULL);
- if (error)
- kn->kn_fflags |= NOTE_TRACKERR;
+ kn->kn_status &= ~KN_MERGE_QOS;
}
-
- return (kn->kn_fflags != 0);
+ if (flags & KNOTE_KQ_UNLOCK) {
+ kqunlock(kq);
+ }
+ if (next_owner_lc) {
+ thread_wakeup_thread(&kn->kn_status, next_owner_lc->knlc_thread);
+ }
+#if DEBUG || DEVELOPMENT
+ knlc->knlc_state = KNOTE_LOCK_CTX_UNLOCKED;
+#endif
}
-#if 0
+/*
+ * Aborts all waiters for a knote lock, and unlock the knote.
+ *
+ * Called with the kqueue lock held.
+ *
+ * Returns with the kqueue lock held according to KNOTE_KQ_* flags
+ */
static void
-filt_timerexpire(void *knx)
+knote_unlock_cancel(struct kqueue *kq, struct knote *kn,
+ struct knote_lock_ctx *knlc, int kqlocking)
{
- struct knote *kn = knx;
- struct callout *calloutp;
- struct timeval tv;
- int tticks;
+ kqlock_held(kq);
+
+ assert(knlc->knlc_knote == kn);
+ assert(kn->kn_status & KN_LOCKED);
+ assert(kn->kn_status & KN_DROPPING);
- kn->kn_data++;
- KNOTE_ACTIVATE(kn);
+ LIST_REMOVE(knlc, knlc_le);
+ kn->kn_status &= ~KN_LOCKED;
- if ((kn->kn_flags & EV_ONESHOT) == 0) {
- tv.tv_sec = kn->kn_sdata / 1000;
- tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
- tticks = tvtohz(&tv);
- calloutp = (struct callout *)kn->kn_hook;
- callout_reset(calloutp, tticks, filt_timerexpire, kn);
+ if (kqlocking == KNOTE_KQ_UNLOCK ||
+ kqlocking == KNOTE_KQ_LOCK_ON_FAILURE) {
+ kqunlock(kq);
}
+ if (!TAILQ_EMPTY(&knlc->knlc_head)) {
+ thread_wakeup_with_result(&kn->kn_status, THREAD_RESTART);
+ }
+#if DEBUG || DEVELOPMENT
+ knlc->knlc_state = KNOTE_LOCK_CTX_UNLOCKED;
+#endif
}
/*
- * data contains amount of time to sleep, in milliseconds
- */
-static int
-filt_timerattach(struct knote *kn)
+ * Call the f_event hook of a given filter.
+ *
+ * Takes a use count to protect against concurrent drops.
+ */
+static void
+knote_call_filter_event(struct kqueue *kq, struct knote *kn, long hint)
{
- struct callout *calloutp;
- struct timeval tv;
- int tticks;
+ int result, dropping = 0;
- if (kq_ncallouts >= kq_calloutmax)
- return (ENOMEM);
- kq_ncallouts++;
+ kqlock_held(kq);
+
+ if (kn->kn_status & (KN_DROPPING | KN_VANISHED))
+ return;
- tv.tv_sec = kn->kn_sdata / 1000;
- tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
- tticks = tvtohz(&tv);
+ kn->kn_inuse++;
+ kqunlock(kq);
+ result = filter_call(knote_fops(kn), f_event(kn, hint));
+ kqlock(kq);
- kn->kn_flags |= EV_CLEAR; /* automatically set */
- MALLOC(calloutp, struct callout *, sizeof(*calloutp),
- M_KQUEUE, M_WAITOK);
- callout_init(calloutp);
- callout_reset(calloutp, tticks, filt_timerexpire, kn);
- kn->kn_hook = (caddr_t)calloutp;
+ dropping = (kn->kn_status & KN_DROPPING);
- return (0);
+ if (!dropping && (result & FILTER_ACTIVE)) {
+ if (result & FILTER_ADJUST_EVENT_QOS_BIT)
+ knote_adjust_qos(kq, kn, result);
+ knote_activate(kn);
+ }
+
+ if (--kn->kn_inuse == 0) {
+ if ((kn->kn_status & KN_LOCKED) == 0) {
+ /*
+ * We're the last f_event() call and there's no other f_* call in
+ * flight, we can leave QoS "Merge" mode.
+ *
+ * See knote_should_apply_qos_override()
+ */
+ kn->kn_status &= ~KN_MERGE_QOS;
+ }
+ if (dropping) {
+ waitq_wakeup64_all((struct waitq *)&kq->kq_wqs,
+ CAST_EVENT64_T(&kn->kn_inuse),
+ THREAD_AWAKENED, WAITQ_ALL_PRIORITIES);
+ }
+ }
}
+/*
+ * Called by knote_drop() to wait for the last f_event() caller to be done.
+ *
+ * - kq locked at entry
+ * - kq unlocked at exit
+ */
static void
-filt_timerdetach(struct knote *kn)
+knote_wait_for_filter_events(struct kqueue *kq, struct knote *kn)
{
- struct callout *calloutp;
+ wait_result_t wr = THREAD_NOT_WAITING;
- calloutp = (struct callout *)kn->kn_hook;
- callout_stop(calloutp);
- FREE(calloutp, M_KQUEUE);
- kq_ncallouts--;
-}
+ kqlock_held(kq);
-static int
-filt_timer(struct knote *kn, long hint)
-{
+ assert(kn->kn_status & KN_DROPPING);
- return (kn->kn_data != 0);
+ if (kn->kn_inuse) {
+ wr = waitq_assert_wait64((struct waitq *)&kq->kq_wqs,
+ CAST_EVENT64_T(&kn->kn_inuse),
+ THREAD_UNINT | THREAD_WAIT_NOREPORT, TIMEOUT_WAIT_FOREVER);
+ }
+ kqunlock(kq);
+ if (wr == THREAD_WAITING) {
+ thread_block(THREAD_CONTINUE_NULL);
+ }
}
-#endif /* 0 */
-/*
- * JMM - placeholder for not-yet-implemented filters
- */
+#pragma mark file_filtops
+
static int
-filt_badattach(struct knote *kn)
+filt_fileattach(struct knote *kn, struct kevent_internal_s *kev)
{
- return(EOPNOTSUPP);
+ return fo_kqfilter(kn->kn_fp, kn, kev, vfs_context_current());
}
-#ifndef _SYS_SYSPROTO_H_
-struct kqueue_args {
- int dummy;
+SECURITY_READ_ONLY_EARLY(static struct filterops) file_filtops = {
+ .f_isfd = 1,
+ .f_attach = filt_fileattach,
};
-#endif
-int
-kqueue(struct proc *p, struct kqueue_args *uap, register_t *retval)
+#pragma mark kqread_filtops
+
+#define f_flag f_fglob->fg_flag
+#define f_ops f_fglob->fg_ops
+#define f_data f_fglob->fg_data
+
+static void
+filt_kqdetach(struct knote *kn)
{
- struct filedesc *fdp = p->p_fd;
- struct kqueue *kq;
- struct file *fp;
- int fd, error;
+ struct kqfile *kqf = (struct kqfile *)kn->kn_fp->f_data;
+ struct kqueue *kq = &kqf->kqf_kqueue;
- error = falloc(p, &fp, &fd);
- if (error)
- return (error);
- fp->f_flag = FREAD | FWRITE;
- fp->f_type = DTYPE_KQUEUE;
- fp->f_ops = &kqueueops;
- kq = (struct kqueue *)_MALLOC(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO);
- TAILQ_INIT(&kq->kq_head);
- fp->f_data = (caddr_t)kq;
- *retval = fd;
- if (fdp->fd_knlistsize < 0)
- fdp->fd_knlistsize = 0; /* this process has a kq */
- kq->kq_fdp = fdp;
- return (error);
+ kqlock(kq);
+ KNOTE_DETACH(&kqf->kqf_sel.si_note, kn);
+ kqunlock(kq);
}
-#ifndef _SYS_SYSPROTO_H_
-struct kqueue_portset_np_args {
- int fd;
-};
-#endif
-int
-kqueue_portset_np(struct proc *p, struct kqueue_portset_np_args *uap, register_t *retval)
+static int
+filt_kqueue(struct knote *kn, __unused long hint)
{
- /* JMM - Placeholder for now */
- return (EOPNOTSUPP);
+ struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+
+ return (kq->kq_count > 0);
}
-#ifndef _SYS_SYSPROTO_H_
-struct kqueue_from_portset_np_args {
- int fd;
-};
-#endif
-int
-kqueue_from_portset_np(struct proc *p, struct kqueue_from_portset_np_args *uap, register_t *retval)
-{
- /* JMM - Placeholder for now */
- return (EOPNOTSUPP);
-}
-
-#if !0
-/* JMM - We don't implement this yet */
-#define fhold(fp)
-#define fdrop(fp, p)
-#endif /* !0 */
-
-#ifndef _SYS_SYSPROTO_H_
-struct kevent_args {
- int fd;
- const struct kevent *changelist;
- int nchanges;
- struct kevent *eventlist;
- int nevents;
- const struct timespec *timeout;
-};
-#endif
-int
-kevent(struct proc *p, struct kevent_args *uap, register_t *retval)
+static int
+filt_kqtouch(struct knote *kn, struct kevent_internal_s *kev)
{
- struct filedesc* fdp = p->p_fd;
- struct kqueue *kq;
- struct file *fp = NULL;
- struct timespec ts;
- int i, nerrors, error;
-
- if (uap->timeout != NULL) {
- error = copyin((caddr_t)uap->timeout, (caddr_t)&ts, sizeof(ts));
- if (error)
- goto done;
- uap->timeout = &ts;
- }
+#pragma unused(kev)
+ struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+ int res;
- if (((u_int)uap->fd) >= fdp->fd_nfiles ||
- (fp = fdp->fd_ofiles[uap->fd]) == NULL ||
- (fp->f_type != DTYPE_KQUEUE))
- return (EBADF);
+ kqlock(kq);
+ kn->kn_data = kq->kq_count;
+ res = (kn->kn_data > 0);
- fhold(fp);
+ kqunlock(kq);
- kq = (struct kqueue *)fp->f_data;
- nerrors = 0;
+ return res;
+}
- while (uap->nchanges > 0) {
- int i;
- int n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges;
- struct kevent kq_kev[n];
+static int
+filt_kqprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+{
+#pragma unused(data)
+ struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
+ int res;
- error = copyin((caddr_t)uap->changelist, (caddr_t)kq_kev,
- n * sizeof(struct kevent));
- if (error)
- goto done;
- for (i = 0; i < n; i++) {
- struct kevent *kevp = &kq_kev[i];
-
- kevp->flags &= ~EV_SYSFLAGS;
- error = kqueue_register(kq, kevp, p);
- if (error) {
- if (uap->nevents != 0) {
- kevp->flags = EV_ERROR;
- kevp->data = error;
- (void) copyout((caddr_t)kevp,
- (caddr_t)uap->eventlist,
- sizeof(*kevp));
- uap->eventlist++;
- uap->nevents--;
- nerrors++;
- } else {
- goto done;
- }
- }
- }
- uap->nchanges -= n;
- uap->changelist += n;
- }
- if (nerrors) {
- *retval = nerrors;
- error = 0;
- goto done;
+ kqlock(kq);
+ kn->kn_data = kq->kq_count;
+ res = (kn->kn_data > 0);
+ if (res) {
+ *kev = kn->kn_kevent;
+ if (kn->kn_flags & EV_CLEAR)
+ kn->kn_data = 0;
}
+ kqunlock(kq);
- error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, retval, p);
-done:
- if (fp != NULL)
- fdrop(fp, p);
- return (error);
+ return res;
}
-int
-kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
+SECURITY_READ_ONLY_EARLY(static struct filterops) kqread_filtops = {
+ .f_isfd = 1,
+ .f_detach = filt_kqdetach,
+ .f_event = filt_kqueue,
+ .f_touch = filt_kqtouch,
+ .f_process = filt_kqprocess,
+};
+
+#pragma mark proc_filtops
+
+static int
+filt_procattach(struct knote *kn, __unused struct kevent_internal_s *kev)
{
- struct filedesc *fdp = kq->kq_fdp;
- struct filterops *fops;
- struct file *fp = NULL;
- struct knote *kn = NULL;
- int s, error = 0;
+ struct proc *p;
- 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);
- }
+ assert(PID_MAX < NOTE_PDATAMASK);
- if (fops->f_isfd) {
- /* validate descriptor */
- if ((u_int)kev->ident >= fdp->fd_nfiles ||
- (fp = fdp->fd_ofiles[kev->ident]) == NULL)
- return (EBADF);
- fhold(fp);
+ if ((kn->kn_sfflags & (NOTE_TRACK | NOTE_TRACKERR | NOTE_CHILD)) != 0) {
+ knote_set_error(kn, ENOTSUP);
+ return 0;
+ }
- if (kev->ident < 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 {
- 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;
- }
+ p = proc_find(kn->kn_id);
+ if (p == NULL) {
+ knote_set_error(kn, ESRCH);
+ return 0;
}
- if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
- error = ENOENT;
- goto done;
- }
+ 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);
+ knote_set_error(kn, EACCES);
+ return 0;
+ } while (0);
+
+ proc_klist_lock();
+
+ kn->kn_ptr.p_proc = p; /* store the proc handle */
+
+ KNOTE_ATTACH(&p->p_klist, kn);
+
+ proc_klist_unlock();
+
+ proc_rele(p);
/*
- * kn now contains the matching knote, or NULL if no match
+ * only captures edge-triggered events after this point
+ * so it can't already be fired.
*/
- if (kev->flags & EV_ADD) {
+ return (0);
+}
- if (kn == NULL) {
- kn = knote_alloc();
- if (kn == NULL) {
- error = ENOMEM;
- goto done;
- }
- kn->kn_fp = fp;
- kn->kn_kq = kq;
- kn->kn_fop = fops;
- /*
- * apply reference count to knote structure, and
- * do not release it at the end of this routine.
- */
- fp = NULL;
+/*
+ * 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;
- kn->kn_sfflags = kev->fflags;
- kn->kn_sdata = kev->data;
- kev->fflags = 0;
- kev->data = 0;
- kn->kn_kevent = *kev;
+ proc_klist_lock();
- knote_fdpattach(kn, fdp);
- if ((error = fops->f_attach(kn)) != 0) {
- knote_drop(kn, p);
- goto done;
- }
- } else {
+ 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)
+{
+ u_int event;
+
+ /* ALWAYS CALLED WITH proc_klist_lock */
+
+ /*
+ * Note: a lot of bits in hint may be obtained from the knote
+ * To free some of those bits, see <rdar://problem/12592988> Freeing up
+ * bits in hint for filt_proc
+ *
+ * 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)
+ && (knote_get_kq(kn)->kq_p->p_pid != kn->kn_ptr.p_proc->p_ppid)) {
/*
- * 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.
+ * This knote is not for the current ptrace(2) parent, ignore.
*/
- kn->kn_sfflags = kev->fflags;
- kn->kn_sdata = kev->data;
- kn->kn_kevent.udata = kev->udata;
+ return 0;
}
+ }
- s = splhigh();
- if (kn->kn_fop->f_event(kn, 0))
- KNOTE_ACTIVATE(kn);
- splx(s);
+ /*
+ * if the user is interested in this event, record it.
+ */
+ if (kn->kn_sfflags & event)
+ kn->kn_fflags |= event;
- } else if (kev->flags & EV_DELETE) {
- kn->kn_fop->f_detach(kn);
- knote_drop(kn, p);
- goto done;
+#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 ((kev->flags & EV_DISABLE) &&
- ((kn->kn_status & KN_DISABLED) == 0)) {
- s = splhigh();
- kn->kn_status |= KN_DISABLED;
- splx(s);
+ /*
+ * The kernel has a wrapper in place that returns the same data
+ * as is collected here, in kn_data. Any changes to how
+ * NOTE_EXITSTATUS and NOTE_EXIT_DETAIL are collected
+ * should also be reflected in the proc_pidnoteexit() wrapper.
+ */
+ if (event == NOTE_EXIT) {
+ kn->kn_data = 0;
+ if ((kn->kn_sfflags & NOTE_EXITSTATUS) != 0) {
+ kn->kn_fflags |= NOTE_EXITSTATUS;
+ kn->kn_data |= (hint & NOTE_PDATAMASK);
+ }
+ if ((kn->kn_sfflags & NOTE_EXIT_DETAIL) != 0) {
+ kn->kn_fflags |= NOTE_EXIT_DETAIL;
+ if ((kn->kn_ptr.p_proc->p_lflag &
+ P_LTERM_DECRYPTFAIL) != 0) {
+ kn->kn_data |= NOTE_EXIT_DECRYPTFAIL;
+ }
+ if ((kn->kn_ptr.p_proc->p_lflag &
+ P_LTERM_JETSAM) != 0) {
+ kn->kn_data |= NOTE_EXIT_MEMORY;
+ switch (kn->kn_ptr.p_proc->p_lflag & P_JETSAM_MASK) {
+ case P_JETSAM_VMPAGESHORTAGE:
+ kn->kn_data |= NOTE_EXIT_MEMORY_VMPAGESHORTAGE;
+ break;
+ case P_JETSAM_VMTHRASHING:
+ kn->kn_data |= NOTE_EXIT_MEMORY_VMTHRASHING;
+ break;
+ case P_JETSAM_FCTHRASHING:
+ kn->kn_data |= NOTE_EXIT_MEMORY_FCTHRASHING;
+ break;
+ case P_JETSAM_VNODE:
+ kn->kn_data |= NOTE_EXIT_MEMORY_VNODE;
+ break;
+ case P_JETSAM_HIWAT:
+ kn->kn_data |= NOTE_EXIT_MEMORY_HIWAT;
+ break;
+ case P_JETSAM_PID:
+ kn->kn_data |= NOTE_EXIT_MEMORY_PID;
+ break;
+ case P_JETSAM_IDLEEXIT:
+ kn->kn_data |= NOTE_EXIT_MEMORY_IDLE;
+ break;
+ }
+ }
+ if ((kn->kn_ptr.p_proc->p_csflags &
+ CS_KILLED) != 0) {
+ kn->kn_data |= NOTE_EXIT_CSERROR;
+ }
+ }
}
- if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
- s = splhigh();
- kn->kn_status &= ~KN_DISABLED;
- if ((kn->kn_status & KN_ACTIVE) &&
- ((kn->kn_status & KN_QUEUED) == 0))
- knote_enqueue(kn);
- splx(s);
+ /* if we have any matching state, activate the knote */
+ return (kn->kn_fflags != 0);
+}
+
+static int
+filt_proctouch(struct knote *kn, struct kevent_internal_s *kev)
+{
+ int res;
+
+ proc_klist_lock();
+
+ /* accept new filter flags and mask off output events no long interesting */
+ kn->kn_sfflags = kev->fflags;
+
+ /* restrict the current results to the (smaller?) set of new interest */
+ /*
+ * For compatibility with previous implementations, we leave kn_fflags
+ * as they were before.
+ */
+ //kn->kn_fflags &= kn->kn_sfflags;
+
+ res = (kn->kn_fflags != 0);
+
+ proc_klist_unlock();
+
+ return res;
+}
+
+static int
+filt_procprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+{
+#pragma unused(data)
+ int res;
+
+ proc_klist_lock();
+ res = (kn->kn_fflags != 0);
+ if (res) {
+ *kev = kn->kn_kevent;
+ kn->kn_flags |= EV_CLEAR; /* automatically set */
+ kn->kn_fflags = 0;
+ kn->kn_data = 0;
}
+ proc_klist_unlock();
+ return res;
+}
-done:
- if (fp != NULL)
- fdrop(fp, p);
- return (error);
+SECURITY_READ_ONLY_EARLY(static struct filterops) proc_filtops = {
+ .f_attach = filt_procattach,
+ .f_detach = filt_procdetach,
+ .f_event = filt_proc,
+ .f_touch = filt_proctouch,
+ .f_process = filt_procprocess,
+};
+
+#pragma mark timer_filtops
+
+struct filt_timer_params {
+ uint64_t deadline; /* deadline in abs/cont time
+ (or 0 if NOTE_ABSOLUTE and deadline is in past) */
+ uint64_t leeway; /* leeway in abstime, or 0 if none */
+ uint64_t interval; /* interval in abstime or 0 if non-repeating timer */
+};
+
+/*
+ * Values stored in the knote at rest (using Mach absolute time units)
+ *
+ * kn->kn_hook where the thread_call object is stored
+ * kn->kn_ext[0] next deadline or 0 if immediate expiration
+ * kn->kn_ext[1] leeway value
+ * kn->kn_sdata interval timer: the interval
+ * absolute/deadline timer: 0
+ * kn->kn_hookid timer state
+ *
+ * TIMER_IDLE:
+ * The timer has either never been scheduled or been cancelled.
+ * It is safe to schedule a new one in this state.
+ *
+ * TIMER_ARMED:
+ * The timer has been scheduled
+ *
+ * TIMER_FIRED
+ * The timer has fired and an event needs to be delivered.
+ * When in this state, the callout may still be running.
+ *
+ * TIMER_IMMEDIATE
+ * The timer has fired at registration time, and the callout was never
+ * dispatched.
+ */
+#define TIMER_IDLE 0x0
+#define TIMER_ARMED 0x1
+#define TIMER_FIRED 0x2
+#define TIMER_IMMEDIATE 0x3
+
+static void
+filt_timer_set_params(struct knote *kn, struct filt_timer_params *params)
+{
+ kn->kn_ext[0] = params->deadline;
+ kn->kn_ext[1] = params->leeway;
+ kn->kn_sdata = params->interval;
}
+/*
+ * filt_timervalidate - process data from user
+ *
+ * Sets up the deadline, interval, and leeway from the provided user data
+ *
+ * Input:
+ * kn_sdata timer deadline or interval time
+ * kn_sfflags style of timer, unit of measurement
+ *
+ * Output:
+ * struct filter_timer_params to apply to the filter with
+ * filt_timer_set_params when changes are ready to be commited.
+ *
+ * Returns:
+ * EINVAL Invalid user data parameters
+ * ERANGE Various overflows with the parameters
+ *
+ * Called with timer filter lock held.
+ */
static int
-kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
- const struct timespec *tsp, register_t *retval, struct proc *p)
+filt_timervalidate(const struct kevent_internal_s *kev,
+ struct filt_timer_params *params)
{
- struct kqueue *kq = (struct kqueue *)fp->f_data;
- struct timeval atv, rtv, ttv;
- int s, count, timeout, error = 0;
- struct knote marker;
+ /*
+ * There are 5 knobs that need to be chosen for a timer registration:
+ *
+ * A) Units of time (what is the time duration of the specified number)
+ * Absolute and interval take:
+ * NOTE_SECONDS, NOTE_USECONDS, NOTE_NSECONDS, NOTE_MACHTIME
+ * Defaults to milliseconds if not specified
+ *
+ * B) Clock epoch (what is the zero point of the specified number)
+ * For interval, there is none
+ * For absolute, defaults to the gettimeofday/calendar epoch
+ * With NOTE_MACHTIME, uses mach_absolute_time()
+ * With NOTE_MACHTIME and NOTE_MACH_CONTINUOUS_TIME, uses mach_continuous_time()
+ *
+ * C) The knote's behavior on delivery
+ * Interval timer causes the knote to arm for the next interval unless one-shot is set
+ * Absolute is a forced one-shot timer which deletes on delivery
+ * TODO: Add a way for absolute to be not forced one-shot
+ *
+ * D) Whether the time duration is relative to now or absolute
+ * Interval fires at now + duration when it is set up
+ * Absolute fires at now + difference between now walltime and passed in walltime
+ * With NOTE_MACHTIME it fires at an absolute MAT or MCT.
+ *
+ * E) Whether the timer continues to tick across sleep
+ * By default all three do not.
+ * For interval and absolute, NOTE_MACH_CONTINUOUS_TIME causes them to tick across sleep
+ * With NOTE_ABSOLUTE | NOTE_MACHTIME | NOTE_MACH_CONTINUOUS_TIME:
+ * expires when mach_continuous_time() is > the passed in value.
+ */
- count = maxevents;
- if (count == 0)
- goto done;
+ uint64_t multiplier;
+
+ boolean_t use_abstime = FALSE;
+
+ switch (kev->fflags & (NOTE_SECONDS|NOTE_USECONDS|NOTE_NSECONDS|NOTE_MACHTIME)) {
+ case NOTE_SECONDS:
+ multiplier = NSEC_PER_SEC;
+ break;
+ case NOTE_USECONDS:
+ multiplier = NSEC_PER_USEC;
+ break;
+ case NOTE_NSECONDS:
+ multiplier = 1;
+ break;
+ case NOTE_MACHTIME:
+ multiplier = 0;
+ use_abstime = TRUE;
+ break;
+ case 0: /* milliseconds (default) */
+ multiplier = NSEC_PER_SEC / 1000;
+ break;
+ default:
+ return (EINVAL);
+ }
- if (tsp != NULL) {
- TIMESPEC_TO_TIMEVAL(&atv, tsp);
- if (itimerfix(&atv)) {
- error = EINVAL;
- goto done;
+ /* transform the leeway in kn_ext[1] to same time scale */
+ if (kev->fflags & NOTE_LEEWAY) {
+ uint64_t leeway_abs;
+
+ if (use_abstime) {
+ leeway_abs = (uint64_t)kev->ext[1];
+ } else {
+ uint64_t leeway_ns;
+ if (os_mul_overflow((uint64_t)kev->ext[1], multiplier, &leeway_ns))
+ return (ERANGE);
+
+ nanoseconds_to_absolutetime(leeway_ns, &leeway_abs);
}
- if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
- timeout = -1;
- else
- timeout = atv.tv_sec > 24 * 60 * 60 ?
- 24 * 60 * 60 * hz : tvtohz(&atv);
- getmicrouptime(&rtv);
- timevaladd(&atv, &rtv);
+
+ params->leeway = leeway_abs;
} else {
- atv.tv_sec = 0;
- atv.tv_usec = 0;
- timeout = 0;
+ params->leeway = 0;
}
- goto start;
-retry:
- if (atv.tv_sec || atv.tv_usec) {
- getmicrouptime(&rtv);
- if (timevalcmp(&rtv, &atv, >=))
- goto done;
- ttv = atv;
- timevalsub(&ttv, &rtv);
- timeout = ttv.tv_sec > 24 * 60 * 60 ?
- 24 * 60 * 60 * hz : tvtohz(&ttv);
- }
+ if (kev->fflags & NOTE_ABSOLUTE) {
+ uint64_t deadline_abs;
-start:
- s = splhigh();
- if (kq->kq_count == 0) {
- if (timeout < 0) {
- error = EWOULDBLOCK;
+ if (use_abstime) {
+ deadline_abs = (uint64_t)kev->data;
} else {
- kq->kq_state |= KQ_SLEEP;
- error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout);
- }
- splx(s);
- if (error == 0)
- goto retry;
- /* don't restart after signals... */
- if (error == ERESTART)
- error = EINTR;
- else if (error == EWOULDBLOCK)
- error = 0;
- goto done;
- }
+ uint64_t calendar_deadline_ns;
- /* JMM - This marker trick doesn't work with multiple threads */
- TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe);
- while (count) {
- int maxkev = (count > KQ_NEVENTS) ? KQ_NEVENTS : count;
- struct kevent kq_kev[maxkev];
- struct kevent *kevp = kq_kev;
- struct knote *kn;
- int nkev = 0;
-
- while (nkev < maxkev) {
- kn = TAILQ_FIRST(&kq->kq_head);
- TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
- if (kn == &marker) {
- if (count == maxevents)
- goto retry;
- break;
- } else if (kn->kn_status & KN_DISABLED) {
- kn->kn_status &= ~KN_QUEUED;
- kq->kq_count--;
- continue;
- } else if ((kn->kn_flags & EV_ONESHOT) == 0 &&
- kn->kn_fop->f_event(kn, 0) == 0) {
- kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
- kq->kq_count--;
- continue;
- }
+ if (os_mul_overflow((uint64_t)kev->data, multiplier, &calendar_deadline_ns))
+ return (ERANGE);
+
+ /* calendar_deadline_ns is in nanoseconds since the epoch */
+
+ clock_sec_t seconds;
+ clock_nsec_t nanoseconds;
+
+ /*
+ * Note that the conversion through wall-time is only done once.
+ *
+ * If the relationship between MAT and gettimeofday changes,
+ * the underlying timer does not update.
+ *
+ * TODO: build a wall-time denominated timer_call queue
+ * and a flag to request DTRTing with wall-time timers
+ */
+ clock_get_calendar_nanotime(&seconds, &nanoseconds);
+
+ uint64_t calendar_now_ns = (uint64_t)seconds * NSEC_PER_SEC + nanoseconds;
+
+ /* if deadline is in the future */
+ if (calendar_now_ns < calendar_deadline_ns) {
+ uint64_t interval_ns = calendar_deadline_ns - calendar_now_ns;
+ uint64_t interval_abs;
- *kevp = kn->kn_kevent;
- kevp++;
- nkev++;
- count--;
-
- if (kn->kn_flags & EV_ONESHOT) {
- kn->kn_status &= ~KN_QUEUED;
- kq->kq_count--;
- splx(s);
- kn->kn_fop->f_detach(kn);
- knote_drop(kn, p);
- s = splhigh();
- } else if (kn->kn_flags & EV_CLEAR) {
- kn->kn_data = 0;
- kn->kn_fflags = 0;
- kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
- kq->kq_count--;
+ nanoseconds_to_absolutetime(interval_ns, &interval_abs);
+
+ /*
+ * Note that the NOTE_MACH_CONTINUOUS_TIME flag here only
+ * causes the timer to keep ticking across sleep, but
+ * it does not change the calendar timebase.
+ */
+
+ if (kev->fflags & NOTE_MACH_CONTINUOUS_TIME)
+ clock_continuoustime_interval_to_deadline(interval_abs,
+ &deadline_abs);
+ else
+ clock_absolutetime_interval_to_deadline(interval_abs,
+ &deadline_abs);
} else {
- TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
+ deadline_abs = 0; /* cause immediate expiration */
}
}
- splx(s);
- error = copyout((caddr_t)kq_kev, (caddr_t)ulistp,
- sizeof(struct kevent) * nkev);
- if (kn == &marker)
- goto done;
- ulistp += nkev;
- s = splhigh();
- if (error)
- break;
+
+ params->deadline = deadline_abs;
+ params->interval = 0; /* NOTE_ABSOLUTE is non-repeating */
+ } else if (kev->data < 0) {
+ /*
+ * Negative interval timers fire immediately, once.
+ *
+ * Ideally a negative interval would be an error, but certain clients
+ * pass negative values on accident, and expect an event back.
+ *
+ * In the old implementation the timer would repeat with no delay
+ * N times until mach_absolute_time() + (N * interval) underflowed,
+ * then it would wait ~forever by accidentally arming a timer for the far future.
+ *
+ * We now skip the power-wasting hot spin phase and go straight to the idle phase.
+ */
+
+ params->deadline = 0; /* expire immediately */
+ params->interval = 0; /* non-repeating */
+ } else {
+ uint64_t interval_abs = 0;
+
+ if (use_abstime) {
+ interval_abs = (uint64_t)kev->data;
+ } else {
+ uint64_t interval_ns;
+ if (os_mul_overflow((uint64_t)kev->data, multiplier, &interval_ns))
+ return (ERANGE);
+
+ nanoseconds_to_absolutetime(interval_ns, &interval_abs);
+ }
+
+ uint64_t deadline = 0;
+
+ if (kev->fflags & NOTE_MACH_CONTINUOUS_TIME)
+ clock_continuoustime_interval_to_deadline(interval_abs, &deadline);
+ else
+ clock_absolutetime_interval_to_deadline(interval_abs, &deadline);
+
+ params->deadline = deadline;
+ params->interval = interval_abs;
}
- TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe);
- splx(s);
-done:
- *retval = maxevents - count;
- return (error);
+
+ return (0);
}
/*
- * XXX
- * This could be expanded to call kqueue_scan, if desired.
+ * filt_timerexpire - the timer callout routine
*/
-/*ARGSUSED*/
-static int
-kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred,
- int flags, struct proc *p)
+static void
+filt_timerexpire(void *knx, __unused void *spare)
{
- return (ENXIO);
+ struct knote *kn = knx;
+ int v;
+
+ if (os_atomic_cmpxchgv(&kn->kn_hookid, TIMER_ARMED, TIMER_FIRED,
+ &v, relaxed)) {
+ // our f_event always would say FILTER_ACTIVE,
+ // so be leaner and just do it.
+ struct kqueue *kq = knote_get_kq(kn);
+ kqlock(kq);
+ knote_activate(kn);
+ kqunlock(kq);
+ } else {
+ /*
+ * From TIMER_ARMED, the only allowed transition are:
+ * - to TIMER_FIRED through the timer callout just above
+ * - to TIMER_IDLE due to filt_timercancel() which will wait for the
+ * timer callout (and any possible invocation of filt_timerexpire) to
+ * have finished before the state is changed again.
+ */
+ assert(v == TIMER_IDLE);
+ }
}
-/*ARGSUSED*/
-static int
-kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred,
- int flags, struct proc *p)
+static void
+filt_timercancel(struct knote *kn)
{
- return (ENXIO);
+ if (os_atomic_xchg(&kn->kn_hookid, TIMER_IDLE, relaxed) == TIMER_ARMED) {
+ /* cancel the thread call and wait for any filt_timerexpire in flight */
+ thread_call_cancel_wait((thread_call_t)kn->kn_hook);
+ }
}
-/*ARGSUSED*/
-static int
-kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p)
+/*
+ * Does this deadline needs a timer armed for it, or has it expired?
+ */
+static bool
+filt_timer_is_ready(struct knote *kn)
{
- return (ENOTTY);
+ uint64_t now, deadline = kn->kn_ext[0];
+
+ if (deadline == 0) {
+ return true;
+ }
+
+ if (kn->kn_sfflags & NOTE_MACH_CONTINUOUS_TIME) {
+ now = mach_continuous_time();
+ } else {
+ now = mach_absolute_time();
+ }
+ return deadline <= now;
}
-/*ARGSUSED*/
+/*
+ * Arm a timer
+ *
+ * It is the responsibility of the caller to make sure the timer call
+ * has completed or been cancelled properly prior to arming it.
+ */
+static void
+filt_timerarm(struct knote *kn)
+{
+ uint64_t deadline = kn->kn_ext[0];
+ uint64_t leeway = kn->kn_ext[1];
+
+ int filter_flags = kn->kn_sfflags;
+ unsigned int timer_flags = 0;
+
+ assert(os_atomic_load(&kn->kn_hookid, relaxed) == TIMER_IDLE);
+
+ if (filter_flags & NOTE_CRITICAL)
+ timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL;
+ else if (filter_flags & NOTE_BACKGROUND)
+ timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND;
+ else
+ timer_flags |= THREAD_CALL_DELAY_USER_NORMAL;
+
+ if (filter_flags & NOTE_LEEWAY)
+ timer_flags |= THREAD_CALL_DELAY_LEEWAY;
+
+ if (filter_flags & NOTE_MACH_CONTINUOUS_TIME)
+ timer_flags |= THREAD_CALL_CONTINUOUS;
+
+ os_atomic_store(&kn->kn_hookid, TIMER_ARMED, relaxed);
+ thread_call_enter_delayed_with_leeway((thread_call_t)kn->kn_hook, NULL,
+ deadline, leeway, timer_flags);
+}
+
+/*
+ * Allocate a thread call for the knote's lifetime, and kick off the timer.
+ */
static int
-kqueue_select(struct file *fp, int which, void *wql, struct proc *p)
+filt_timerattach(struct knote *kn, struct kevent_internal_s *kev)
{
- struct kqueue *kq = (struct kqueue *)fp->f_data;
- int retnum = 0;
- int s = splnet();
+ thread_call_t callout;
+ struct filt_timer_params params;
+ int error;
- if (which == FREAD) {
- if (kq->kq_count) {
- retnum = 1;
- } else {
- selrecord(p, &kq->kq_sel, wql);
- kq->kq_state |= KQ_SEL;
- }
+ if ((error = filt_timervalidate(kev, ¶ms)) != 0) {
+ knote_set_error(kn, error);
+ return 0;
+ }
+
+ callout = thread_call_allocate_with_options(filt_timerexpire,
+ (thread_call_param_t)kn, THREAD_CALL_PRIORITY_HIGH,
+ THREAD_CALL_OPTIONS_ONCE);
+
+ if (NULL == callout) {
+ knote_set_error(kn, ENOMEM);
+ return 0;
+ }
+
+ filt_timer_set_params(kn, ¶ms);
+ kn->kn_hook = callout;
+ kn->kn_flags |= EV_CLEAR;
+ os_atomic_store(&kn->kn_hookid, TIMER_IDLE, relaxed);
+
+ /* NOTE_ABSOLUTE implies EV_ONESHOT */
+ if (kn->kn_sfflags & NOTE_ABSOLUTE)
+ kn->kn_flags |= EV_ONESHOT;
+
+ if (filt_timer_is_ready(kn)) {
+ os_atomic_store(&kn->kn_hookid, TIMER_IMMEDIATE, relaxed);
+ return FILTER_ACTIVE;
+ } else {
+ filt_timerarm(kn);
+ return 0;
}
- splx(s);
- return (retnum);
}
-/*ARGSUSED*/
+/*
+ * Shut down the timer if it's running, and free the callout.
+ */
+static void
+filt_timerdetach(struct knote *kn)
+{
+ __assert_only boolean_t freed;
+
+ /*
+ * Unconditionally cancel to make sure there can't be any filt_timerexpire()
+ * running anymore.
+ */
+ thread_call_cancel_wait((thread_call_t)kn->kn_hook);
+ freed = thread_call_free((thread_call_t)kn->kn_hook);
+ assert(freed);
+}
+
+/*
+ * filt_timertouch - update timer 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 int
-kqueue_close(struct file *fp, struct proc *p)
+filt_timertouch(struct knote *kn, struct kevent_internal_s *kev)
{
- struct kqueue *kq = (struct kqueue *)fp->f_data;
- struct filedesc *fdp = p->p_fd;
- struct knote **knp, *kn, *kn0;
- int i;
+ struct filt_timer_params params;
+ uint32_t changed_flags = (kn->kn_sfflags ^ kev->fflags);
+ int error;
+
+ if (changed_flags & NOTE_ABSOLUTE) {
+ kev->flags |= EV_ERROR;
+ kev->data = EINVAL;
+ return 0;
+ }
- for (i = 0; i < fdp->fd_knlistsize; i++) {
- knp = &SLIST_FIRST(&fdp->fd_knlist[i]);
- kn = *knp;
- while (kn != NULL) {
- kn0 = SLIST_NEXT(kn, kn_link);
- if (kq == kn->kn_kq) {
- kn->kn_fop->f_detach(kn);
- fdrop(kn->kn_fp, p);
- knote_free(kn);
- *knp = kn0;
- } else {
- knp = &SLIST_NEXT(kn, kn_link);
- }
- kn = kn0;
- }
+ if ((error = filt_timervalidate(kev, ¶ms)) != 0) {
+ kev->flags |= EV_ERROR;
+ kev->data = error;
+ return 0;
}
- if (fdp->fd_knhashmask != 0) {
- for (i = 0; i < fdp->fd_knhashmask + 1; i++) {
- knp = &SLIST_FIRST(&fdp->fd_knhash[i]);
- kn = *knp;
- while (kn != NULL) {
- kn0 = SLIST_NEXT(kn, kn_link);
- if (kq == kn->kn_kq) {
- kn->kn_fop->f_detach(kn);
- /* XXX non-fd release of kn->kn_ptr */
- knote_free(kn);
- *knp = kn0;
- } else {
- knp = &SLIST_NEXT(kn, kn_link);
+
+ /* capture the new values used to compute deadline */
+ filt_timercancel(kn);
+ filt_timer_set_params(kn, ¶ms);
+ kn->kn_sfflags = kev->fflags;
+
+ if (filt_timer_is_ready(kn)) {
+ os_atomic_store(&kn->kn_hookid, TIMER_IMMEDIATE, relaxed);
+ return FILTER_ACTIVE | FILTER_UPDATE_REQ_QOS;
+ } else {
+ filt_timerarm(kn);
+ return FILTER_UPDATE_REQ_QOS;
+ }
+}
+
+/*
+ * filt_timerprocess - query state of knote and snapshot event data
+ *
+ * Determine if the timer has fired in the past, snapshot the state
+ * of the kevent for returning to user-space, and clear pending event
+ * counters for the next time.
+ */
+static int
+filt_timerprocess(
+ struct knote *kn,
+ __unused struct filt_process_s *data,
+ struct kevent_internal_s *kev)
+{
+ /*
+ * filt_timerprocess is serialized with any filter routine except for
+ * filt_timerexpire which atomically does a TIMER_ARMED -> TIMER_FIRED
+ * transition, and on success, activates the knote.
+ *
+ * Hence, we don't need atomic modifications of the state, only to peek at
+ * whether we see any of the "FIRED" state, and if we do, it is safe to
+ * do simple state machine transitions.
+ */
+ switch (os_atomic_load(&kn->kn_hookid, relaxed)) {
+ case TIMER_IDLE:
+ case TIMER_ARMED:
+ /*
+ * This can happen if a touch resets a timer that had fired
+ * without being processed
+ */
+ return 0;
+ }
+
+ os_atomic_store(&kn->kn_hookid, TIMER_IDLE, relaxed);
+
+ /*
+ * Copy out the interesting kevent state,
+ * but don't leak out the raw time calculations.
+ *
+ * TODO: potential enhancements - tell the user about:
+ * - deadline to which this timer thought it was expiring
+ * - return kn_sfflags in the fflags field so the client can know
+ * under what flags the timer fired
+ */
+ *kev = kn->kn_kevent;
+ kev->ext[0] = 0;
+ /* kev->ext[1] = 0; JMM - shouldn't we hide this too? */
+
+ if (kn->kn_sdata == 0) {
+ kev->data = 1;
+ } else {
+ /*
+ * This is a 'repeating' timer, so we have to emit
+ * how many intervals expired between the arm
+ * and the process.
+ *
+ * A very strange style of interface, because
+ * this could easily be done in the client...
+ */
+
+ uint64_t now;
+
+ if (kn->kn_sfflags & NOTE_MACH_CONTINUOUS_TIME)
+ now = mach_continuous_time();
+ else
+ now = mach_absolute_time();
+
+ uint64_t first_deadline = kn->kn_ext[0];
+ uint64_t interval_abs = kn->kn_sdata;
+ uint64_t orig_arm_time = first_deadline - interval_abs;
+
+ assert(now > orig_arm_time);
+ assert(now > first_deadline);
+
+ uint64_t elapsed = now - orig_arm_time;
+
+ uint64_t num_fired = elapsed / interval_abs;
+
+ /*
+ * To reach this code, we must have seen the timer pop
+ * and be in repeating mode, so therefore it must have been
+ * more than 'interval' time since the attach or last
+ * successful touch.
+ */
+ assert(num_fired > 0);
+
+ /* report how many intervals have elapsed to the user */
+ kev->data = (int64_t)num_fired;
+
+ /* We only need to re-arm the timer if it's not about to be destroyed */
+ if ((kn->kn_flags & EV_ONESHOT) == 0) {
+ /* fire at the end of the next interval */
+ uint64_t new_deadline = first_deadline + num_fired * interval_abs;
+
+ assert(new_deadline > now);
+
+ kn->kn_ext[0] = new_deadline;
+
+ /*
+ * This can't shortcut setting up the thread call, because
+ * knote_process deactivates EV_CLEAR knotes unconditionnally.
+ */
+ filt_timerarm(kn);
+ }
+ }
+
+ return FILTER_ACTIVE;
+}
+
+SECURITY_READ_ONLY_EARLY(static struct filterops) timer_filtops = {
+ .f_extended_codes = true,
+ .f_attach = filt_timerattach,
+ .f_detach = filt_timerdetach,
+ .f_event = filt_badevent,
+ .f_touch = filt_timertouch,
+ .f_process = filt_timerprocess,
+};
+
+#pragma mark user_filtops
+
+static int
+filt_userattach(struct knote *kn, __unused struct kevent_internal_s *kev)
+{
+ if (kn->kn_sfflags & NOTE_TRIGGER) {
+ kn->kn_hookid = FILTER_ACTIVE;
+ } else {
+ kn->kn_hookid = 0;
+ }
+ return (kn->kn_hookid);
+}
+
+static void
+filt_userdetach(__unused struct knote *kn)
+{
+ /* EVFILT_USER knotes are not attached to anything in the kernel */
+}
+
+static int
+filt_usertouch(struct knote *kn, struct kevent_internal_s *kev)
+{
+ uint32_t ffctrl;
+ int fflags;
+
+ ffctrl = kev->fflags & NOTE_FFCTRLMASK;
+ fflags = kev->fflags & NOTE_FFLAGSMASK;
+ switch (ffctrl) {
+ case NOTE_FFNOP:
+ break;
+ case NOTE_FFAND:
+ kn->kn_sfflags &= fflags;
+ break;
+ case NOTE_FFOR:
+ kn->kn_sfflags |= fflags;
+ break;
+ case NOTE_FFCOPY:
+ kn->kn_sfflags = fflags;
+ break;
+ }
+ kn->kn_sdata = kev->data;
+
+ if (kev->fflags & NOTE_TRIGGER) {
+ kn->kn_hookid = FILTER_ACTIVE;
+ }
+ return (int)kn->kn_hookid;
+}
+
+static int
+filt_userprocess(
+ struct knote *kn,
+ __unused struct filt_process_s *data,
+ struct kevent_internal_s *kev)
+{
+ int result = (int)kn->kn_hookid;
+
+ if (result) {
+ *kev = kn->kn_kevent;
+ kev->fflags = kn->kn_sfflags;
+ kev->data = kn->kn_sdata;
+ if (kn->kn_flags & EV_CLEAR) {
+ kn->kn_hookid = 0;
+ kn->kn_data = 0;
+ kn->kn_fflags = 0;
+ }
+ }
+
+ return result;
+}
+
+SECURITY_READ_ONLY_EARLY(static struct filterops) user_filtops = {
+ .f_extended_codes = true,
+ .f_attach = filt_userattach,
+ .f_detach = filt_userdetach,
+ .f_event = filt_badevent,
+ .f_touch = filt_usertouch,
+ .f_process = filt_userprocess,
+};
+
+#pragma mark workloop_filtops
+
+static inline void
+filt_wllock(struct kqworkloop *kqwl)
+{
+ lck_mtx_lock(&kqwl->kqwl_statelock);
+}
+
+static inline void
+filt_wlunlock(struct kqworkloop *kqwl)
+{
+ lck_mtx_unlock(&kqwl->kqwl_statelock);
+}
+
+/*
+ * Returns true when the interlock for the turnstile is the workqueue lock
+ *
+ * When this is the case, all turnstiles operations are delegated
+ * to the workqueue subsystem.
+ *
+ * This is required because kqueue_threadreq_bind_prepost only holds the
+ * workqueue lock but needs to move the inheritor from the workloop turnstile
+ * away from the creator thread, so that this now fulfilled request cannot be
+ * picked anymore by other threads.
+ */
+static inline bool
+filt_wlturnstile_interlock_is_workq(struct kqworkloop *kqwl)
+{
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ return (kqr->kqr_state & KQR_THREQUESTED) &&
+ (kqr->kqr_thread == THREAD_NULL);
+}
+
+static void
+filt_wlupdate_inheritor(struct kqworkloop *kqwl, struct turnstile *ts,
+ turnstile_update_flags_t flags)
+{
+ turnstile_inheritor_t inheritor = TURNSTILE_INHERITOR_NULL;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ /*
+ * binding to the workq should always happen through
+ * workq_kern_threadreq_update_inheritor()
+ */
+ assert(!filt_wlturnstile_interlock_is_workq(kqwl));
+
+ if ((inheritor = kqwl->kqwl_owner)) {
+ flags |= TURNSTILE_INHERITOR_THREAD;
+ } else if ((inheritor = kqr->kqr_thread)) {
+ flags |= TURNSTILE_INHERITOR_THREAD;
+ }
+
+ turnstile_update_inheritor(ts, inheritor, flags);
+}
+
+#define FILT_WLATTACH 0
+#define FILT_WLTOUCH 1
+#define FILT_WLDROP 2
+
+__result_use_check
+static int
+filt_wlupdate(struct kqworkloop *kqwl, struct knote *kn,
+ struct kevent_internal_s *kev, kq_index_t qos_index, int op)
+{
+ user_addr_t uaddr = CAST_USER_ADDR_T(kev->ext[EV_EXTIDX_WL_ADDR]);
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ thread_t cur_owner, new_owner, extra_thread_ref = THREAD_NULL;
+ kq_index_t cur_owner_override = THREAD_QOS_UNSPECIFIED;
+ int action = KQWL_UTQ_NONE, error = 0;
+ bool needs_wake = false, needs_wllock = false;
+ uint64_t kdata = kev->ext[EV_EXTIDX_WL_VALUE];
+ uint64_t mask = kev->ext[EV_EXTIDX_WL_MASK];
+ uint64_t udata = 0;
+
+ if (kev->fflags & (NOTE_WL_END_OWNERSHIP | NOTE_WL_DISCOVER_OWNER)) {
+ /*
+ * If we're maybe going to change the kqwl_owner,
+ * then we need to hold the filt_wllock().
+ */
+ needs_wllock = true;
+ } else if (kqr->kqr_thread == current_thread()) {
+ /*
+ * <rdar://problem/41531764> Servicer updates need to be serialized with
+ * any ownership change too, as the kqr_thread value influences the
+ * outcome of handling NOTE_WL_DISCOVER_OWNER.
+ */
+ needs_wllock = true;
+ }
+
+ if (needs_wllock) {
+ filt_wllock(kqwl);
+ /*
+ * The kqwl owner is set under both the req and filter lock,
+ * meaning it's fine to look at it under any.
+ */
+ new_owner = cur_owner = kqwl->kqwl_owner;
+ } else {
+ new_owner = cur_owner = THREAD_NULL;
+ }
+
+ /*
+ * Phase 1:
+ *
+ * If asked, load the uint64 value at the user provided address and compare
+ * it against the passed in mask and expected value.
+ *
+ * If NOTE_WL_DISCOVER_OWNER is specified, translate the loaded name as
+ * a thread reference.
+ *
+ * If NOTE_WL_END_OWNERSHIP is specified and the currently known owner is
+ * the current thread, then end ownership.
+ *
+ * Lastly decide whether we need to perform a QoS update.
+ */
+ if (uaddr) {
+ error = copyin_word(uaddr, &udata, sizeof(udata));
+ if (error) {
+ goto out;
+ }
+
+ /* Update state as copied in. */
+ kev->ext[EV_EXTIDX_WL_VALUE] = udata;
+
+ if ((udata & mask) != (kdata & mask)) {
+ error = ESTALE;
+ } else if (kev->fflags & NOTE_WL_DISCOVER_OWNER) {
+ /*
+ * Decipher the owner port name, and translate accordingly.
+ * The low 2 bits were borrowed for other flags, so mask them off.
+ *
+ * Then attempt translation to a thread reference or fail.
+ */
+ mach_port_name_t name = (mach_port_name_t)udata & ~0x3;
+ if (name != MACH_PORT_NULL) {
+ name = ipc_entry_name_mask(name);
+ extra_thread_ref = port_name_to_thread(name);
+ if (extra_thread_ref == THREAD_NULL) {
+ error = EOWNERDEAD;
+ goto out;
+ }
+ new_owner = extra_thread_ref;
+ }
+ }
+ }
+
+ if ((kev->fflags & NOTE_WL_END_OWNERSHIP) && new_owner == current_thread()) {
+ new_owner = THREAD_NULL;
+ }
+
+ if (error == 0) {
+ if ((kev->fflags & NOTE_WL_THREAD_REQUEST) && (kev->flags & EV_DELETE)) {
+ action = KQWL_UTQ_SET_QOS_INDEX;
+ } else if (qos_index && kqr->kqr_qos_index != qos_index) {
+ action = KQWL_UTQ_SET_QOS_INDEX;
+ }
+
+ if (op == FILT_WLTOUCH) {
+ /*
+ * Save off any additional fflags/data we just accepted
+ * But only keep the last round of "update" bits we acted on which helps
+ * debugging a lot.
+ */
+ kn->kn_sfflags &= ~NOTE_WL_UPDATES_MASK;
+ kn->kn_sfflags |= kev->fflags;
+ kn->kn_sdata = kev->data;
+ if (kev->fflags & NOTE_WL_SYNC_WAKE) {
+ needs_wake = (kn->kn_hook != THREAD_NULL);
+ }
+ } else if (op == FILT_WLDROP) {
+ if ((kn->kn_sfflags & (NOTE_WL_SYNC_WAIT | NOTE_WL_SYNC_WAKE)) ==
+ NOTE_WL_SYNC_WAIT) {
+ /*
+ * When deleting a SYNC_WAIT knote that hasn't been woken up
+ * explicitly, issue a wake up.
+ */
+ kn->kn_sfflags |= NOTE_WL_SYNC_WAKE;
+ needs_wake = (kn->kn_hook != THREAD_NULL);
+ }
+ }
+ }
+
+ /*
+ * Phase 2:
+ *
+ * Commit ownership and QoS changes if any, possibly wake up waiters
+ */
+
+ if (cur_owner == new_owner && action == KQWL_UTQ_NONE && !needs_wake) {
+ goto out;
+ }
+
+ kq_req_lock(kqwl);
+
+ /* If already tracked as servicer, don't track as owner */
+ if (new_owner == kqr->kqr_thread) {
+ new_owner = THREAD_NULL;
+ }
+
+ if (cur_owner != new_owner) {
+ kqwl->kqwl_owner = new_owner;
+ if (new_owner == extra_thread_ref) {
+ /* we just transfered this ref to kqwl_owner */
+ extra_thread_ref = THREAD_NULL;
+ }
+ cur_owner_override = kqworkloop_owner_override(kqwl);
+
+ if (cur_owner) {
+ thread_ends_owning_workloop(cur_owner);
+ }
+
+ if (new_owner) {
+ /* override it before we drop the old */
+ if (cur_owner_override != THREAD_QOS_UNSPECIFIED) {
+ thread_add_ipc_override(new_owner, cur_owner_override);
+ }
+ thread_starts_owning_workloop(new_owner);
+ if ((kqr->kqr_state & KQR_THREQUESTED) && !kqr->kqr_thread) {
+ if (action == KQWL_UTQ_NONE) {
+ action = KQWL_UTQ_REDRIVE_EVENTS;
+ }
+ }
+ } else {
+ if ((kqr->kqr_state & (KQR_THREQUESTED | KQR_WAKEUP)) == KQR_WAKEUP) {
+ if (action == KQWL_UTQ_NONE) {
+ action = KQWL_UTQ_REDRIVE_EVENTS;
+ }
+ }
+ }
+ }
+
+ struct turnstile *ts = kqwl->kqwl_turnstile;
+ bool wl_inheritor_updated = false;
+
+ if (action != KQWL_UTQ_NONE) {
+ kqworkloop_update_threads_qos(kqwl, action, qos_index);
+ }
+
+ if (cur_owner != new_owner && ts) {
+ if (action == KQWL_UTQ_REDRIVE_EVENTS) {
+ /*
+ * Note that when action is KQWL_UTQ_REDRIVE_EVENTS,
+ * the code went through workq_kern_threadreq_initiate()
+ * and the workqueue has set the inheritor already
+ */
+ assert(filt_wlturnstile_interlock_is_workq(kqwl));
+ } else if (filt_wlturnstile_interlock_is_workq(kqwl)) {
+ workq_kern_threadreq_lock(kqwl->kqwl_p);
+ workq_kern_threadreq_update_inheritor(kqwl->kqwl_p, kqr, new_owner,
+ ts, TURNSTILE_IMMEDIATE_UPDATE);
+ workq_kern_threadreq_unlock(kqwl->kqwl_p);
+ if (!filt_wlturnstile_interlock_is_workq(kqwl)) {
+ /*
+ * If the workq is no longer the interlock, then
+ * workq_kern_threadreq_update_inheritor() has finished a bind
+ * and we need to fallback to the regular path.
+ */
+ filt_wlupdate_inheritor(kqwl, ts, TURNSTILE_IMMEDIATE_UPDATE);
+ }
+ wl_inheritor_updated = true;
+ } else {
+ filt_wlupdate_inheritor(kqwl, ts, TURNSTILE_IMMEDIATE_UPDATE);
+ wl_inheritor_updated = true;
+ }
+
+ /*
+ * We need a turnstile reference because we are dropping the interlock
+ * and the caller has not called turnstile_prepare.
+ */
+ if (wl_inheritor_updated) {
+ turnstile_reference(ts);
+ }
+ }
+
+ if (needs_wake && ts) {
+ waitq_wakeup64_thread(&ts->ts_waitq, CAST_EVENT64_T((event_t)kn),
+ (thread_t)kn->kn_hook, THREAD_AWAKENED);
+ }
+
+ kq_req_unlock(kqwl);
+
+ if (wl_inheritor_updated) {
+ turnstile_update_inheritor_complete(ts, TURNSTILE_INTERLOCK_NOT_HELD);
+ turnstile_deallocate(ts);
+ }
+
+out:
+ /*
+ * Phase 3:
+ *
+ * Unlock and cleanup various lingering references and things.
+ */
+ if (needs_wllock) {
+ filt_wlunlock(kqwl);
+ }
+
+#if CONFIG_WORKLOOP_DEBUG
+ KQWL_HISTORY_WRITE_ENTRY(kqwl, {
+ .updater = current_thread(),
+ .servicer = kqr->kqr_thread, /* Note: racy */
+ .old_owner = cur_owner,
+ .new_owner = new_owner,
+
+ .kev_ident = kev->ident,
+ .error = (int16_t)error,
+ .kev_flags = kev->flags,
+ .kev_fflags = kev->fflags,
+
+ .kev_mask = mask,
+ .kev_value = kdata,
+ .in_value = udata,
+ });
+#endif // CONFIG_WORKLOOP_DEBUG
+
+ if (cur_owner && new_owner != cur_owner) {
+ if (cur_owner_override != THREAD_QOS_UNSPECIFIED) {
+ thread_drop_ipc_override(cur_owner);
+ }
+ thread_deallocate(cur_owner);
+ }
+
+ if (extra_thread_ref) {
+ thread_deallocate(extra_thread_ref);
+ }
+ return error;
+}
+
+/*
+ * Remembers the last updated that came in from userspace for debugging reasons.
+ * - fflags is mirrored from the userspace kevent
+ * - ext[i, i != VALUE] is mirrored from the userspace kevent
+ * - ext[VALUE] is set to what the kernel loaded atomically
+ * - data is set to the error if any
+ */
+static inline void
+filt_wlremember_last_update(struct knote *kn, struct kevent_internal_s *kev,
+ int error)
+{
+ kn->kn_fflags = kev->fflags;
+ kn->kn_data = error;
+ memcpy(kn->kn_ext, kev->ext, sizeof(kev->ext));
+}
+
+static int
+filt_wlattach(struct knote *kn, struct kevent_internal_s *kev)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ int error = 0;
+ kq_index_t qos_index = 0;
+
+ if ((kq->kq_state & KQ_WORKLOOP) == 0) {
+ error = ENOTSUP;
+ goto out;
+ }
+
+#if DEVELOPMENT || DEBUG
+ if (kev->ident == 0 && kev->udata == 0 && kev->fflags == 0) {
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ kq_req_lock(kqwl);
+ kev->fflags = 0;
+ if (kqr->kqr_dsync_waiters) {
+ kev->fflags |= NOTE_WL_SYNC_WAIT;
+ }
+ if (kqr->kqr_qos_index) {
+ kev->fflags |= NOTE_WL_THREAD_REQUEST;
+ }
+ kev->ext[0] = thread_tid(kqwl->kqwl_owner);
+ kev->ext[1] = thread_tid(kqwl->kqwl_request.kqr_thread);
+ kev->ext[2] = thread_owned_workloops_count(current_thread());
+ kev->ext[3] = kn->kn_kevent.ext[3];
+ kq_req_unlock(kqwl);
+ error = EBUSY;
+ goto out;
+ }
+#endif
+
+ int command = (kn->kn_sfflags & NOTE_WL_COMMANDS_MASK);
+ switch (command) {
+ case NOTE_WL_THREAD_REQUEST:
+ if (kn->kn_id != kqwl->kqwl_dynamicid) {
+ error = EINVAL;
+ goto out;
+ }
+ qos_index = _pthread_priority_thread_qos(kn->kn_qos);
+ if (qos_index == THREAD_QOS_UNSPECIFIED) {
+ error = ERANGE;
+ goto out;
+ }
+ if (kqwl->kqwl_request.kqr_qos_index) {
+ /*
+ * There already is a thread request, and well, you're only allowed
+ * one per workloop, so fail the attach.
+ */
+ error = EALREADY;
+ goto out;
+ }
+ break;
+ case NOTE_WL_SYNC_WAIT:
+ case NOTE_WL_SYNC_WAKE:
+ if (kn->kn_id == kqwl->kqwl_dynamicid) {
+ error = EINVAL;
+ goto out;
+ }
+ if ((kn->kn_flags & EV_DISABLE) == 0) {
+ error = EINVAL;
+ goto out;
+ }
+ if (kn->kn_sfflags & NOTE_WL_END_OWNERSHIP) {
+ error = EINVAL;
+ goto out;
+ }
+ break;
+ default:
+ error = EINVAL;
+ goto out;
+ }
+
+ error = filt_wlupdate(kqwl, kn, kev, qos_index, FILT_WLATTACH);
+
+out:
+ if (error) {
+ /* If userland wants ESTALE to be hidden, fail the attach anyway */
+ if (error == ESTALE && (kn->kn_sfflags & NOTE_WL_IGNORE_ESTALE)) {
+ error = 0;
+ }
+ knote_set_error(kn, error);
+ return 0;
+ }
+ if (command == NOTE_WL_SYNC_WAIT) {
+ return kevent_register_wait_prepare(kn, kev);
+ }
+ /* Just attaching the thread request successfully will fire it */
+ if (command == NOTE_WL_THREAD_REQUEST) {
+ /*
+ * Thread Request knotes need an explicit touch to be active again,
+ * so delivering an event needs to also consume it.
+ */
+ kn->kn_flags |= EV_CLEAR;
+ return FILTER_ACTIVE;
+ }
+ return 0;
+}
+
+static void __dead2
+filt_wlwait_continue(void *parameter, wait_result_t wr)
+{
+ struct _kevent_register *cont_args = parameter;
+ struct kqworkloop *kqwl = (struct kqworkloop *)cont_args->kq;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ kq_req_lock(kqwl);
+ kqr->kqr_dsync_waiters--;
+ if (filt_wlturnstile_interlock_is_workq(kqwl)) {
+ workq_kern_threadreq_lock(kqwl->kqwl_p);
+ turnstile_complete((uintptr_t)kqwl, &kqwl->kqwl_turnstile, NULL);
+ workq_kern_threadreq_unlock(kqwl->kqwl_p);
+ } else {
+ turnstile_complete((uintptr_t)kqwl, &kqwl->kqwl_turnstile, NULL);
+ }
+ kq_req_unlock(kqwl);
+
+ turnstile_cleanup();
+
+ if (wr == THREAD_INTERRUPTED) {
+ cont_args->kev.flags |= EV_ERROR;
+ cont_args->kev.data = EINTR;
+ } else if (wr != THREAD_AWAKENED) {
+ panic("Unexpected wait result: %d", wr);
+ }
+
+ kevent_register_wait_return(cont_args);
+}
+
+/*
+ * Called with the workloop mutex held, most of the time never returns as it
+ * calls filt_wlwait_continue through a continuation.
+ */
+static void __dead2
+filt_wlpost_register_wait(struct uthread *uth, struct knote_lock_ctx *knlc,
+ struct _kevent_register *cont_args)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)cont_args->kq;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ struct turnstile *ts;
+ bool workq_locked = false;
+
+ kq_req_lock(kqwl);
+
+ kqr->kqr_dsync_waiters++;
+
+ if (filt_wlturnstile_interlock_is_workq(kqwl)) {
+ workq_kern_threadreq_lock(kqwl->kqwl_p);
+ workq_locked = true;
+ }
+
+ ts = turnstile_prepare((uintptr_t)kqwl, &kqwl->kqwl_turnstile,
+ TURNSTILE_NULL, TURNSTILE_WORKLOOPS);
+
+ if (workq_locked) {
+ workq_kern_threadreq_update_inheritor(kqwl->kqwl_p,
+ &kqwl->kqwl_request, kqwl->kqwl_owner, ts,
+ TURNSTILE_DELAYED_UPDATE);
+ if (!filt_wlturnstile_interlock_is_workq(kqwl)) {
+ /*
+ * if the interlock is no longer the workqueue lock,
+ * then we don't need to hold it anymore.
+ */
+ workq_kern_threadreq_unlock(kqwl->kqwl_p);
+ workq_locked = false;
+ }
+ }
+ if (!workq_locked) {
+ /*
+ * If the interlock is the workloop's, then it's our responsibility to
+ * call update_inheritor, so just do it.
+ */
+ filt_wlupdate_inheritor(kqwl, ts, TURNSTILE_DELAYED_UPDATE);
+ }
+
+ thread_set_pending_block_hint(uth->uu_thread, kThreadWaitWorkloopSyncWait);
+ waitq_assert_wait64(&ts->ts_waitq, CAST_EVENT64_T(cont_args->knote),
+ THREAD_ABORTSAFE, TIMEOUT_WAIT_FOREVER);
+
+ if (workq_locked) {
+ workq_kern_threadreq_unlock(kqwl->kqwl_p);
+ }
+
+ thread_t thread = kqwl->kqwl_owner ?: kqr->kqr_thread;
+ if (thread) {
+ thread_reference(thread);
+ }
+ kq_req_unlock(kqwl);
+
+ kevent_register_wait_block(ts, thread, knlc, filt_wlwait_continue, cont_args);
+}
+
+/* called in stackshot context to report the thread responsible for blocking this thread */
+void
+kdp_workloop_sync_wait_find_owner(__assert_only thread_t thread,
+ event64_t event, thread_waitinfo_t *waitinfo)
+{
+ struct knote *kn = (struct knote *)event;
+ assert(kdp_is_in_zone(kn, "knote zone"));
+
+ assert(kn->kn_hook == thread);
+
+ struct kqueue *kq = knote_get_kq(kn);
+ assert(kdp_is_in_zone(kq, "kqueue workloop zone"));
+ assert(kq->kq_state & KQ_WORKLOOP);
+
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ thread_t kqwl_owner = kqwl->kqwl_owner;
+ thread_t servicer = kqr->kqr_thread;
+
+ if (kqwl_owner != THREAD_NULL) {
+ assert(kdp_is_in_zone(kqwl_owner, "threads"));
+
+ waitinfo->owner = thread_tid(kqwl->kqwl_owner);
+ } else if (servicer != THREAD_NULL) {
+ assert(kdp_is_in_zone(servicer, "threads"));
+
+ waitinfo->owner = thread_tid(servicer);
+ } else if (kqr->kqr_state & KQR_THREQUESTED) {
+ waitinfo->owner = STACKSHOT_WAITOWNER_THREQUESTED;
+ } else {
+ waitinfo->owner = 0;
+ }
+
+ waitinfo->context = kqwl->kqwl_dynamicid;
+}
+
+static void
+filt_wldetach(__assert_only struct knote *kn)
+{
+ assert(knote_get_kq(kn)->kq_state & KQ_WORKLOOP);
+ if (kn->kn_hook) {
+ kevent_register_wait_cleanup(kn);
+ }
+}
+
+static int
+filt_wlvalidate_kev_flags(struct knote *kn, struct kevent_internal_s *kev,
+ thread_qos_t *qos_index)
+{
+ int new_commands = kev->fflags & NOTE_WL_COMMANDS_MASK;
+ int sav_commands = kn->kn_sfflags & NOTE_WL_COMMANDS_MASK;
+
+ if ((kev->fflags & NOTE_WL_DISCOVER_OWNER) && (kev->flags & EV_DELETE)) {
+ return EINVAL;
+ }
+ if (kev->fflags & NOTE_WL_UPDATE_QOS) {
+ if (kev->flags & EV_DELETE) {
+ return EINVAL;
+ }
+ if (sav_commands != NOTE_WL_THREAD_REQUEST) {
+ return EINVAL;
+ }
+ if (!(*qos_index = _pthread_priority_thread_qos(kev->qos))) {
+ return ERANGE;
+ }
+ }
+
+ switch (new_commands) {
+ case NOTE_WL_THREAD_REQUEST:
+ /* thread requests can only update themselves */
+ if (sav_commands != NOTE_WL_THREAD_REQUEST)
+ return EINVAL;
+ break;
+
+ case NOTE_WL_SYNC_WAIT:
+ if (kev->fflags & NOTE_WL_END_OWNERSHIP)
+ return EINVAL;
+ goto sync_checks;
+
+ case NOTE_WL_SYNC_WAKE:
+ sync_checks:
+ if (!(sav_commands & (NOTE_WL_SYNC_WAIT | NOTE_WL_SYNC_WAKE)))
+ return EINVAL;
+ if ((kev->flags & (EV_ENABLE | EV_DELETE)) == EV_ENABLE)
+ return EINVAL;
+ break;
+
+ default:
+ return EINVAL;
+ }
+ return 0;
+}
+
+static int
+filt_wltouch(struct knote *kn, struct kevent_internal_s *kev)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)knote_get_kq(kn);
+ thread_qos_t qos_index = THREAD_QOS_UNSPECIFIED;
+
+ int error = filt_wlvalidate_kev_flags(kn, kev, &qos_index);
+ if (error) {
+ goto out;
+ }
+
+ error = filt_wlupdate(kqwl, kn, kev, qos_index, FILT_WLTOUCH);
+ filt_wlremember_last_update(kn, kev, error);
+ if (error) {
+ goto out;
+ }
+
+out:
+ if (error) {
+ if (error == ESTALE && (kev->fflags & NOTE_WL_IGNORE_ESTALE)) {
+ /* If userland wants ESTALE to be hidden, do not activate */
+ return 0;
+ }
+ kev->flags |= EV_ERROR;
+ kev->data = error;
+ return 0;
+ }
+ int command = kev->fflags & NOTE_WL_COMMANDS_MASK;
+ if (command == NOTE_WL_SYNC_WAIT && !(kn->kn_sfflags & NOTE_WL_SYNC_WAKE)) {
+ return kevent_register_wait_prepare(kn, kev);
+ }
+ /* Just touching the thread request successfully will fire it */
+ if (command == NOTE_WL_THREAD_REQUEST) {
+ if (kev->fflags & NOTE_WL_UPDATE_QOS) {
+ return FILTER_ACTIVE | FILTER_UPDATE_REQ_QOS;
+ }
+ return FILTER_ACTIVE;
+ }
+ return 0;
+}
+
+static bool
+filt_wlallow_drop(struct knote *kn, struct kevent_internal_s *kev)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)knote_get_kq(kn);
+
+ int error = filt_wlvalidate_kev_flags(kn, kev, NULL);
+ if (error) {
+ goto out;
+ }
+
+ error = filt_wlupdate(kqwl, kn, kev, 0, FILT_WLDROP);
+ filt_wlremember_last_update(kn, kev, error);
+ if (error) {
+ goto out;
+ }
+
+out:
+ if (error) {
+ if (error == ESTALE && (kev->fflags & NOTE_WL_IGNORE_ESTALE)) {
+ return false;
+ }
+ kev->flags |= EV_ERROR;
+ kev->data = error;
+ return false;
+ }
+ return true;
+}
+
+static int
+filt_wlprocess(
+ struct knote *kn,
+ __unused struct filt_process_s *data,
+ struct kevent_internal_s *kev)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)knote_get_kq(kn);
+ int rc = 0;
+
+ assert(kn->kn_sfflags & NOTE_WL_THREAD_REQUEST);
+
+ filt_wllock(kqwl);
+
+ if (kqwl->kqwl_owner) {
+ /*
+ * <rdar://problem/33584321> userspace sometimes due to events being
+ * delivered but not triggering a drain session can cause a process
+ * of the thread request knote.
+ *
+ * When that happens, the automatic deactivation due to process
+ * would swallow the event, so we have to activate the knote again.
+ */
+ kqlock(kqwl);
+ knote_activate(kn);
+ kqunlock(kqwl);
+ } else {
+#if DEBUG || DEVELOPMENT
+ if (kevent_debug_flags() & KEVENT_PANIC_ON_NON_ENQUEUED_PROCESS) {
+ /*
+ * see src/queue_internal.h in libdispatch
+ */
+#define DISPATCH_QUEUE_ENQUEUED 0x1ull
+ user_addr_t addr = CAST_USER_ADDR_T(kn->kn_ext[EV_EXTIDX_WL_ADDR]);
+ task_t t = current_task();
+ uint64_t val;
+ if (addr && task_is_active(t) && !task_is_halting(t) &&
+ copyin_word(addr, &val, sizeof(val)) == 0 &&
+ val && (val & DISPATCH_QUEUE_ENQUEUED) == 0 &&
+ (val >> 48) != 0xdead && (val >> 48) != 0 && (val >> 48) != 0xffff) {
+ panic("kevent: workloop %#016llx is not enqueued "
+ "(kn:%p dq_state:%#016llx kev.dq_state:%#016llx)",
+ kn->kn_udata, kn, val, kn->kn_ext[EV_EXTIDX_WL_VALUE]);
+ }
+ }
+#endif
+ *kev = kn->kn_kevent;
+ kev->fflags = kn->kn_sfflags;
+ kev->data = kn->kn_sdata;
+ kev->qos = kn->kn_qos;
+ rc |= FILTER_ACTIVE;
+ }
+
+ filt_wlunlock(kqwl);
+
+ if (rc & FILTER_ACTIVE) {
+ workq_thread_set_max_qos(kqwl->kqwl_p, &kqwl->kqwl_request);
+ }
+ return rc;
+}
+
+SECURITY_READ_ONLY_EARLY(static struct filterops) workloop_filtops = {
+ .f_extended_codes = true,
+ .f_attach = filt_wlattach,
+ .f_detach = filt_wldetach,
+ .f_event = filt_badevent,
+ .f_touch = filt_wltouch,
+ .f_process = filt_wlprocess,
+ .f_allow_drop = filt_wlallow_drop,
+ .f_post_register_wait = filt_wlpost_register_wait,
+};
+
+#pragma mark kevent / knotes
+
+/*
+ * JMM - placeholder for not-yet-implemented filters
+ */
+static int
+filt_badevent(struct knote *kn, long hint)
+{
+ panic("%s[%d](%p, %ld)", __func__, kn->kn_filter, kn, hint);
+ return 0;
+}
+
+static int
+filt_badattach(__unused struct knote *kn, __unused struct kevent_internal_s *kev)
+{
+ knote_set_error(kn, ENOTSUP);
+ return 0;
+}
+
+struct kqueue *
+kqueue_alloc(struct proc *p, unsigned int flags)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct kqueue *kq = NULL;
+ int policy;
+ void *hook = NULL;
+
+ if (flags & KEVENT_FLAG_WORKQ) {
+ struct kqworkq *kqwq;
+ int i;
+
+ kqwq = (struct kqworkq *)zalloc(kqworkq_zone);
+ if (kqwq == NULL)
+ return NULL;
+
+ kq = &kqwq->kqwq_kqueue;
+ bzero(kqwq, sizeof (struct kqworkq));
+
+ kqwq->kqwq_state = KQ_WORKQ;
+
+ for (i = 0; i < KQWQ_NBUCKETS; i++) {
+ TAILQ_INIT(&kqwq->kqwq_queue[i]);
+ }
+ for (i = 0; i < KQWQ_NBUCKETS; i++) {
+ if (i != KQWQ_QOS_MANAGER) {
+ /*
+ * Because of how the bucketized system works, we mix overcommit
+ * sources with not overcommit: each time we move a knote from
+ * one bucket to the next due to overrides, we'd had to track
+ * overcommitness, and it's really not worth it in the workloop
+ * enabled world that track this faithfully.
+ *
+ * Incidentally, this behaves like the original manager-based
+ * kqwq where event delivery always happened (hence is
+ * "overcommit")
+ */
+ kqwq->kqwq_request[i].kqr_state |= KQR_THOVERCOMMIT;
+ }
+ kqwq->kqwq_request[i].kqr_qos_index = i;
+ TAILQ_INIT(&kqwq->kqwq_request[i].kqr_suppressed);
+ }
+
+ policy = SYNC_POLICY_FIFO;
+ hook = (void *)kqwq;
+ } else if (flags & KEVENT_FLAG_WORKLOOP) {
+ struct kqworkloop *kqwl;
+ int i;
+
+ kqwl = (struct kqworkloop *)zalloc(kqworkloop_zone);
+ if (kqwl == NULL)
+ return NULL;
+
+ bzero(kqwl, sizeof (struct kqworkloop));
+
+ kqwl->kqwl_state = KQ_WORKLOOP | KQ_DYNAMIC;
+ kqwl->kqwl_retains = 1; /* donate a retain to creator */
+ kqwl->kqwl_request.kqr_state = KQR_WORKLOOP;
+
+ kq = &kqwl->kqwl_kqueue;
+ for (i = 0; i < KQWL_NBUCKETS; i++) {
+ TAILQ_INIT(&kqwl->kqwl_queue[i]);
+ }
+ TAILQ_INIT(&kqwl->kqwl_request.kqr_suppressed);
+
+ lck_mtx_init(&kqwl->kqwl_statelock, kq_lck_grp, kq_lck_attr);
+
+ policy = SYNC_POLICY_FIFO;
+ hook = (void *)kqwl;
+ } else {
+ struct kqfile *kqf;
+
+ kqf = (struct kqfile *)zalloc(kqfile_zone);
+ if (kqf == NULL)
+ return NULL;
+
+ kq = &kqf->kqf_kqueue;
+ bzero(kqf, sizeof (struct kqfile));
+ TAILQ_INIT(&kqf->kqf_queue);
+ TAILQ_INIT(&kqf->kqf_suppressed);
+
+ policy = SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST;
+ }
+
+ waitq_set_init(&kq->kq_wqs, policy, NULL, hook);
+ lck_spin_init(&kq->kq_lock, kq_lck_grp, kq_lck_attr);
+ lck_spin_init(&kq->kq_reqlock, kq_lck_grp, kq_lck_attr);
+ 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);
+}
+
+/*
+ * knotes_dealloc - detach all knotes for the process and drop them
+ *
+ * Called with proc_fdlock held.
+ * Returns with it locked.
+ * May drop it temporarily.
+ * Process is in such a state that it will not try to allocate
+ * any more knotes during this process (stopped for exit or exec).
+ */
+void
+knotes_dealloc(proc_t p)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct kqueue *kq;
+ struct knote *kn;
+ struct klist *kn_hash = NULL;
+ int i;
+
+ /* Close all the fd-indexed knotes up front */
+ if (fdp->fd_knlistsize > 0) {
+ for (i = 0; i < fdp->fd_knlistsize; i++) {
+ while ((kn = SLIST_FIRST(&fdp->fd_knlist[i])) != NULL) {
+ kq = knote_get_kq(kn);
+ kqlock(kq);
+ proc_fdunlock(p);
+ knote_drop(kq, kn, NULL);
+ proc_fdlock(p);
+ }
+ }
+ /* free the table */
+ FREE(fdp->fd_knlist, M_KQUEUE);
+ fdp->fd_knlist = NULL;
+ }
+ fdp->fd_knlistsize = -1;
+
+ knhash_lock(p);
+ proc_fdunlock(p);
+
+ /* Clean out all the hashed knotes as well */
+ if (fdp->fd_knhashmask != 0) {
+ for (i = 0; i <= (int)fdp->fd_knhashmask; i++) {
+ while ((kn = SLIST_FIRST(&fdp->fd_knhash[i])) != NULL) {
+ kq = knote_get_kq(kn);
+ kqlock(kq);
+ knhash_unlock(p);
+ knote_drop(kq, kn, NULL);
+ knhash_lock(p);
+ }
+ }
+ kn_hash = fdp->fd_knhash;
+ fdp->fd_knhashmask = 0;
+ fdp->fd_knhash = NULL;
+ }
+
+ knhash_unlock(p);
+
+ /* free the kn_hash table */
+ if (kn_hash)
+ FREE(kn_hash, M_KQUEUE);
+
+ proc_fdlock(p);
+}
+
+/*
+ * kqworkloop_invalidate
+ *
+ * Invalidate ownership of a workloop.
+ *
+ * This is meant to be used so that any remnant of overrides and ownership
+ * information is dropped before a kqworkloop can no longer be found in the
+ * global hash table and have ghost workloop ownership left over.
+ *
+ * Possibly returns a thread to deallocate in a safe context.
+ */
+static thread_t
+kqworkloop_invalidate(struct kqworkloop *kqwl)
+{
+ thread_t cur_owner = kqwl->kqwl_owner;
+
+ assert(TAILQ_EMPTY(&kqwl->kqwl_request.kqr_suppressed));
+ if (cur_owner) {
+ /*
+ * If the kqueue had an owner that prevented the thread request to
+ * go through, then no unbind happened, and we may have lingering
+ * overrides to drop.
+ */
+ if (kqworkloop_owner_override(kqwl) != THREAD_QOS_UNSPECIFIED) {
+ thread_drop_ipc_override(cur_owner);
+ }
+ thread_ends_owning_workloop(cur_owner);
+ kqwl->kqwl_owner = THREAD_NULL;
+ }
+
+ return cur_owner;
+}
+
+/*
+ * 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.
+ *
+ * Workloop kqueues cant get here unless all the knotes
+ * are already gone and all requested threads have come
+ * and gone (cancelled or arrived).
+ */
+void
+kqueue_dealloc(struct kqueue *kq)
+{
+ struct proc *p;
+ struct filedesc *fdp;
+ struct knote *kn;
+ int i;
+
+ if (kq == NULL)
+ return;
+
+ p = kq->kq_p;
+ fdp = p->p_fd;
+
+ /*
+ * Workloops are refcounted by their knotes, so there's no point
+ * spending a lot of time under these locks just to deallocate one.
+ */
+ if ((kq->kq_state & KQ_WORKLOOP) == 0) {
+ KNOTE_LOCK_CTX(knlc);
+
+ proc_fdlock(p);
+ for (i = 0; i < fdp->fd_knlistsize; i++) {
+ kn = SLIST_FIRST(&fdp->fd_knlist[i]);
+ while (kn != NULL) {
+ if (kq == knote_get_kq(kn)) {
+ kqlock(kq);
+ proc_fdunlock(p);
+ if (knote_lock(kq, kn, &knlc, KNOTE_KQ_LOCK_ON_SUCCESS)) {
+ knote_drop(kq, kn, &knlc);
+ }
+ proc_fdlock(p);
+ /* start over at beginning of list */
+ kn = SLIST_FIRST(&fdp->fd_knlist[i]);
+ continue;
+ }
+ kn = SLIST_NEXT(kn, kn_link);
+ }
+ }
+
+ knhash_lock(p);
+ proc_fdunlock(p);
+
+ 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 == knote_get_kq(kn)) {
+ kqlock(kq);
+ knhash_unlock(p);
+ if (knote_lock(kq, kn, &knlc, KNOTE_KQ_LOCK_ON_SUCCESS)) {
+ knote_drop(kq, kn, &knlc);
+ }
+ knhash_lock(p);
+ /* start over at beginning of list */
+ kn = SLIST_FIRST(&fdp->fd_knhash[i]);
+ continue;
+ }
+ kn = SLIST_NEXT(kn, kn_link);
+ }
+ }
+ }
+ knhash_unlock(p);
+ }
+
+ if (kq->kq_state & KQ_WORKLOOP) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ thread_t cur_owner = kqworkloop_invalidate(kqwl);
+
+ if (cur_owner) thread_deallocate(cur_owner);
+
+ if (kqwl->kqwl_request.kqr_state & KQR_ALLOCATED_TURNSTILE) {
+ struct turnstile *ts;
+ turnstile_complete((uintptr_t)kqwl, &kqwl->kqwl_turnstile, &ts);
+ turnstile_cleanup();
+ turnstile_deallocate(ts);
+ } else {
+ assert(kqwl->kqwl_turnstile == NULL);
+ }
+ }
+
+ /*
+ * waitq_set_deinit() remove the KQ's waitq set from
+ * any select sets to which it may belong.
+ */
+ waitq_set_deinit(&kq->kq_wqs);
+ lck_spin_destroy(&kq->kq_lock, kq_lck_grp);
+ lck_spin_destroy(&kq->kq_reqlock, kq_lck_grp);
+
+ if (kq->kq_state & KQ_WORKQ) {
+ zfree(kqworkq_zone, (struct kqworkq *)kq);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+
+ assert(kqwl->kqwl_retains == 0);
+ lck_mtx_destroy(&kqwl->kqwl_statelock, kq_lck_grp);
+ zfree(kqworkloop_zone, kqwl);
+ } else {
+ zfree(kqfile_zone, (struct kqfile *)kq);
+ }
+}
+
+static inline void
+kqueue_retain(struct kqueue *kq)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ uint32_t previous;
+
+ if ((kq->kq_state & KQ_DYNAMIC) == 0)
+ return;
+
+ previous = OSIncrementAtomic(&kqwl->kqwl_retains);
+ if (previous == KQ_WORKLOOP_RETAINS_MAX)
+ panic("kq(%p) retain overflow", kq);
+
+ if (previous == 0)
+ panic("kq(%p) resurrection", kq);
+}
+
+#define KQUEUE_CANT_BE_LAST_REF 0
+#define KQUEUE_MIGHT_BE_LAST_REF 1
+
+static inline int
+kqueue_release(kqueue_t kqu, __assert_only int possibly_last)
+{
+ if ((kqu.kq->kq_state & KQ_DYNAMIC) == 0) {
+ return 0;
+ }
+
+ assert(kqu.kq->kq_state & KQ_WORKLOOP); /* for now */
+ uint32_t refs = OSDecrementAtomic(&kqu.kqwl->kqwl_retains);
+ if (__improbable(refs == 0)) {
+ panic("kq(%p) over-release", kqu.kq);
+ }
+ if (refs == 1) {
+ assert(possibly_last);
+ }
+ return refs == 1;
+}
+
+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, 0);
+ 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 kevent_internal_s *kevp, struct proc *p,
+ unsigned int flags)
+{
+ int advance;
+ int error;
+
+ if (flags & KEVENT_FLAG_LEGACY32) {
+ bzero(kevp, sizeof (*kevp));
+
+ if (IS_64BIT_PROCESS(p)) {
+ struct user64_kevent kev64;
+
+ 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->udata = kev64.udata;
+ kevp->fflags = kev64.fflags;
+ kevp->data = kev64.data;
+ } else {
+ struct user32_kevent kev32;
+
+ 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->udata = CAST_USER_ADDR_T(kev32.udata);
+ kevp->fflags = kev32.fflags;
+ kevp->data = (intptr_t)kev32.data;
+ }
+ } else if (flags & KEVENT_FLAG_LEGACY64) {
+ struct kevent64_s kev64;
+
+ bzero(kevp, sizeof (*kevp));
+
+ advance = sizeof (struct kevent64_s);
+ error = copyin(*addrp, (caddr_t)&kev64, advance);
+ if (error)
+ return(error);
+ kevp->ident = kev64.ident;
+ kevp->filter = kev64.filter;
+ kevp->flags = kev64.flags;
+ kevp->udata = kev64.udata;
+ kevp->fflags = kev64.fflags;
+ kevp->data = kev64.data;
+ kevp->ext[0] = kev64.ext[0];
+ kevp->ext[1] = kev64.ext[1];
+
+ } else {
+ struct kevent_qos_s kevqos;
+
+ bzero(kevp, sizeof (*kevp));
+
+ advance = sizeof (struct kevent_qos_s);
+ error = copyin(*addrp, (caddr_t)&kevqos, advance);
+ if (error)
+ return error;
+ kevp->ident = kevqos.ident;
+ kevp->filter = kevqos.filter;
+ kevp->flags = kevqos.flags;
+ kevp->qos = kevqos.qos;
+// kevp->xflags = kevqos.xflags;
+ kevp->udata = kevqos.udata;
+ kevp->fflags = kevqos.fflags;
+ kevp->data = kevqos.data;
+ kevp->ext[0] = kevqos.ext[0];
+ kevp->ext[1] = kevqos.ext[1];
+ kevp->ext[2] = kevqos.ext[2];
+ kevp->ext[3] = kevqos.ext[3];
+ }
+ if (!error)
+ *addrp += advance;
+ return (error);
+}
+
+static int
+kevent_copyout(struct kevent_internal_s *kevp, user_addr_t *addrp, struct proc *p,
+ unsigned int flags)
+{
+ user_addr_t addr = *addrp;
+ int advance;
+ int error;
+
+ /*
+ * fully initialize the differnt output event structure
+ * types from the internal kevent (and some universal
+ * defaults for fields not represented in the internal
+ * form).
+ */
+ if (flags & KEVENT_FLAG_LEGACY32) {
+ assert((flags & KEVENT_FLAG_STACK_EVENTS) == 0);
+
+ if (IS_64BIT_PROCESS(p)) {
+ struct user64_kevent kev64;
+
+ advance = sizeof (kev64);
+ bzero(&kev64, advance);
+
+ /*
+ * 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;
+ error = copyout((caddr_t)&kev64, addr, advance);
+ } else {
+ struct user32_kevent kev32;
+
+ advance = sizeof (kev32);
+ bzero(&kev32, advance);
+ 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;
+ error = copyout((caddr_t)&kev32, addr, advance);
+ }
+ } else if (flags & KEVENT_FLAG_LEGACY64) {
+ struct kevent64_s kev64;
+
+ advance = sizeof (struct kevent64_s);
+ if (flags & KEVENT_FLAG_STACK_EVENTS) {
+ addr -= advance;
+ }
+ bzero(&kev64, advance);
+ kev64.ident = kevp->ident;
+ kev64.filter = kevp->filter;
+ kev64.flags = kevp->flags;
+ kev64.fflags = kevp->fflags;
+ kev64.data = (int64_t) kevp->data;
+ kev64.udata = kevp->udata;
+ kev64.ext[0] = kevp->ext[0];
+ kev64.ext[1] = kevp->ext[1];
+ error = copyout((caddr_t)&kev64, addr, advance);
+ } else {
+ struct kevent_qos_s kevqos;
+
+ advance = sizeof (struct kevent_qos_s);
+ if (flags & KEVENT_FLAG_STACK_EVENTS) {
+ addr -= advance;
+ }
+ bzero(&kevqos, advance);
+ kevqos.ident = kevp->ident;
+ kevqos.filter = kevp->filter;
+ kevqos.flags = kevp->flags;
+ kevqos.qos = kevp->qos;
+ kevqos.udata = kevp->udata;
+ kevqos.fflags = kevp->fflags;
+ kevqos.xflags = 0;
+ kevqos.data = (int64_t) kevp->data;
+ kevqos.ext[0] = kevp->ext[0];
+ kevqos.ext[1] = kevp->ext[1];
+ kevqos.ext[2] = kevp->ext[2];
+ kevqos.ext[3] = kevp->ext[3];
+ error = copyout((caddr_t)&kevqos, addr, advance);
+ }
+ if (!error) {
+ if (flags & KEVENT_FLAG_STACK_EVENTS)
+ *addrp = addr;
+ else
+ *addrp = addr + advance;
+ }
+ return (error);
+}
+
+static int
+kevent_get_data_size(
+ struct proc *p,
+ uint64_t data_available,
+ unsigned int flags,
+ user_size_t *residp)
+{
+ user_size_t resid;
+ int error = 0;
+
+ if (data_available != USER_ADDR_NULL) {
+ if (flags & KEVENT_FLAG_KERNEL) {
+ resid = *(user_size_t *)(uintptr_t)data_available;
+ } else if (IS_64BIT_PROCESS(p)) {
+ user64_size_t usize;
+ error = copyin((user_addr_t)data_available, &usize, sizeof(usize));
+ resid = (user_size_t)usize;
+ } else {
+ user32_size_t usize;
+ error = copyin((user_addr_t)data_available, &usize, sizeof(usize));
+ resid = (user_size_t)usize;
+ }
+ if (error)
+ return(error);
+ } else {
+ resid = 0;
+ }
+ *residp = resid;
+ return 0;
+}
+
+static int
+kevent_put_data_size(
+ struct proc *p,
+ uint64_t data_available,
+ unsigned int flags,
+ user_size_t resid)
+{
+ int error = 0;
+
+ if (data_available) {
+ if (flags & KEVENT_FLAG_KERNEL) {
+ *(user_size_t *)(uintptr_t)data_available = resid;
+ } else if (IS_64BIT_PROCESS(p)) {
+ user64_size_t usize = (user64_size_t)resid;
+ error = copyout(&usize, (user_addr_t)data_available, sizeof(usize));
+ } else {
+ user32_size_t usize = (user32_size_t)resid;
+ error = copyout(&usize, (user_addr_t)data_available, sizeof(usize));
+ }
+ }
+ return error;
+}
+
+/*
+ * kevent_continue - continue a kevent syscall after blocking
+ *
+ * assume we inherit a use count on the kq fileglob.
+ */
+__attribute__((noreturn))
+static void
+kevent_continue(__unused struct kqueue *kq, void *data, int error)
+{
+ struct _kevent *cont_args;
+ struct fileproc *fp;
+ uint64_t data_available;
+ user_size_t data_size;
+ user_size_t data_resid;
+ unsigned int flags;
+ int32_t *retval;
+ int noutputs;
+ int fd;
+ struct proc *p = current_proc();
+
+ cont_args = (struct _kevent *)data;
+ data_available = cont_args->data_available;
+ flags = cont_args->process_data.fp_flags;
+ data_size = cont_args->process_data.fp_data_size;
+ data_resid = cont_args->process_data.fp_data_resid;
+ noutputs = cont_args->eventout;
+ retval = cont_args->retval;
+ fd = cont_args->fd;
+ fp = cont_args->fp;
+
+ kevent_put_kq(p, fd, fp, kq);
+
+ /* don't abandon other output just because of residual copyout failures */
+ if (error == 0 && data_available && data_resid != data_size) {
+ (void)kevent_put_data_size(p, data_available, flags, data_resid);
+ }
+
+ /* 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)
+{
+ unsigned int flags = KEVENT_FLAG_LEGACY32;
+
+ return kevent_internal(p,
+ (kqueue_id_t)uap->fd, NULL,
+ uap->changelist, uap->nchanges,
+ uap->eventlist, uap->nevents,
+ 0ULL, 0ULL,
+ flags,
+ uap->timeout,
+ kevent_continue,
+ retval);
+}
+
+int
+kevent64(struct proc *p, struct kevent64_args *uap, int32_t *retval)
+{
+ unsigned int flags;
+
+ /* restrict to user flags and set legacy64 */
+ flags = uap->flags & KEVENT_FLAG_USER;
+ flags |= KEVENT_FLAG_LEGACY64;
+
+ return kevent_internal(p,
+ (kqueue_id_t)uap->fd, NULL,
+ uap->changelist, uap->nchanges,
+ uap->eventlist, uap->nevents,
+ 0ULL, 0ULL,
+ flags,
+ uap->timeout,
+ kevent_continue,
+ retval);
+}
+
+int
+kevent_qos(struct proc *p, struct kevent_qos_args *uap, int32_t *retval)
+{
+ /* restrict to user flags */
+ uap->flags &= KEVENT_FLAG_USER;
+
+ return kevent_internal(p,
+ (kqueue_id_t)uap->fd, NULL,
+ uap->changelist, uap->nchanges,
+ uap->eventlist, uap->nevents,
+ uap->data_out, (uint64_t)uap->data_available,
+ uap->flags,
+ 0ULL,
+ kevent_continue,
+ retval);
+}
+
+int
+kevent_qos_internal(struct proc *p, int fd,
+ user_addr_t changelist, int nchanges,
+ user_addr_t eventlist, int nevents,
+ user_addr_t data_out, user_size_t *data_available,
+ unsigned int flags,
+ int32_t *retval)
+{
+ return kevent_internal(p,
+ (kqueue_id_t)fd, NULL,
+ changelist, nchanges,
+ eventlist, nevents,
+ data_out, (uint64_t)data_available,
+ (flags | KEVENT_FLAG_KERNEL),
+ 0ULL,
+ NULL,
+ retval);
+}
+
+int
+kevent_id(struct proc *p, struct kevent_id_args *uap, int32_t *retval)
+{
+ /* restrict to user flags */
+ uap->flags &= KEVENT_FLAG_USER;
+
+ return kevent_internal(p,
+ (kqueue_id_t)uap->id, NULL,
+ uap->changelist, uap->nchanges,
+ uap->eventlist, uap->nevents,
+ uap->data_out, (uint64_t)uap->data_available,
+ (uap->flags | KEVENT_FLAG_DYNAMIC_KQUEUE),
+ 0ULL,
+ kevent_continue,
+ retval);
+}
+
+int
+kevent_id_internal(struct proc *p, kqueue_id_t *id,
+ user_addr_t changelist, int nchanges,
+ user_addr_t eventlist, int nevents,
+ user_addr_t data_out, user_size_t *data_available,
+ unsigned int flags,
+ int32_t *retval)
+{
+ return kevent_internal(p,
+ *id, id,
+ changelist, nchanges,
+ eventlist, nevents,
+ data_out, (uint64_t)data_available,
+ (flags | KEVENT_FLAG_KERNEL | KEVENT_FLAG_DYNAMIC_KQUEUE),
+ 0ULL,
+ NULL,
+ retval);
+}
+
+static int
+kevent_get_timeout(struct proc *p,
+ user_addr_t utimeout,
+ unsigned int flags,
+ struct timeval *atvp)
+{
+ struct timeval atv;
+ int error = 0;
+
+ if (flags & KEVENT_FLAG_IMMEDIATE) {
+ getmicrouptime(&atv);
+ } else if (utimeout != USER_ADDR_NULL) {
+ struct timeval rtv;
+ if (flags & KEVENT_FLAG_KERNEL) {
+ struct timespec *tsp = (struct timespec *)utimeout;
+ TIMESPEC_TO_TIMEVAL(&rtv, tsp);
+ } else 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 {
+ /* wait forever value */
+ atv.tv_sec = 0;
+ atv.tv_usec = 0;
+ }
+ *atvp = atv;
+ return 0;
+}
+
+static int
+kevent_set_kq_mode(struct kqueue *kq, unsigned int flags)
+{
+ /* each kq should only be used for events of one type */
+ kqlock(kq);
+ if (kq->kq_state & (KQ_KEV32 | KQ_KEV64 | KQ_KEV_QOS)) {
+ if (flags & KEVENT_FLAG_LEGACY32) {
+ if ((kq->kq_state & KQ_KEV32) == 0) {
+ kqunlock(kq);
+ return EINVAL;
+ }
+ } else if (kq->kq_state & KQ_KEV32) {
+ kqunlock(kq);
+ return EINVAL;
+ }
+ } else if (flags & KEVENT_FLAG_LEGACY32) {
+ kq->kq_state |= KQ_KEV32;
+ } else if (flags & KEVENT_FLAG_LEGACY64) {
+ kq->kq_state |= KQ_KEV64;
+ } else {
+ kq->kq_state |= KQ_KEV_QOS;
+ }
+ kqunlock(kq);
+ return 0;
+}
+
+#define KQ_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
+#define CONFIG_KQ_HASHSIZE CONFIG_KN_HASHSIZE
+
+static inline void
+kqhash_lock(proc_t p)
+{
+ lck_mtx_lock_spin_always(&p->p_fd->fd_kqhashlock);
+}
+
+static inline void
+kqhash_lock_held(__assert_only proc_t p)
+{
+ LCK_MTX_ASSERT(&p->p_fd->fd_kqhashlock, LCK_MTX_ASSERT_OWNED);
+}
+
+static inline void
+kqhash_unlock(proc_t p)
+{
+ lck_mtx_unlock(&p->p_fd->fd_kqhashlock);
+}
+
+static void
+kqueue_hash_init_if_needed(proc_t p)
+{
+ struct filedesc *fdp = p->p_fd;
+
+ kqhash_lock_held(p);
+
+ if (__improbable(fdp->fd_kqhash == NULL)) {
+ struct kqlist *alloc_hash;
+ u_long alloc_mask;
+
+ kqhash_unlock(p);
+ alloc_hash = hashinit(CONFIG_KQ_HASHSIZE, M_KQUEUE, &alloc_mask);
+ kqhash_lock(p);
+
+ /* See if we won the race */
+ if (fdp->fd_kqhashmask == 0) {
+ fdp->fd_kqhash = alloc_hash;
+ fdp->fd_kqhashmask = alloc_mask;
+ } else {
+ kqhash_unlock(p);
+ FREE(alloc_hash, M_KQUEUE);
+ kqhash_lock(p);
+ }
+ }
+}
+
+/*
+ * Called with the kqhash_lock() held
+ */
+static void
+kqueue_hash_insert(
+ struct proc *p,
+ kqueue_id_t id,
+ struct kqueue *kq)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ struct filedesc *fdp = p->p_fd;
+ struct kqlist *list;
+
+ /* should hold the kq hash lock */
+ kqhash_lock_held(p);
+
+ if ((kq->kq_state & KQ_DYNAMIC) == 0) {
+ assert(kq->kq_state & KQ_DYNAMIC);
+ return;
+ }
+
+ /* only dynamically allocate workloop kqs for now */
+ assert(kq->kq_state & KQ_WORKLOOP);
+ assert(fdp->fd_kqhash);
+
+ kqwl->kqwl_dynamicid = id;
+
+ list = &fdp->fd_kqhash[KQ_HASH(id, fdp->fd_kqhashmask)];
+ SLIST_INSERT_HEAD(list, kqwl, kqwl_hashlink);
+}
+
+/* Called with kqhash_lock held */
+static void
+kqueue_hash_remove(
+ struct proc *p,
+ struct kqueue *kq)
+{
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ struct filedesc *fdp = p->p_fd;
+ struct kqlist *list;
+
+ /* should hold the kq hash lock */
+ kqhash_lock_held(p);
+
+ if ((kq->kq_state & KQ_DYNAMIC) == 0) {
+ assert(kq->kq_state & KQ_DYNAMIC);
+ return;
+ }
+ assert(kq->kq_state & KQ_WORKLOOP); /* for now */
+ list = &fdp->fd_kqhash[KQ_HASH(kqwl->kqwl_dynamicid, fdp->fd_kqhashmask)];
+ SLIST_REMOVE(list, kqwl, kqworkloop, kqwl_hashlink);
+}
+
+/* Called with kqhash_lock held */
+static struct kqueue *
+kqueue_hash_lookup(struct proc *p, kqueue_id_t id)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct kqlist *list;
+ struct kqworkloop *kqwl;
+
+ /* should hold the kq hash lock */
+ kqhash_lock_held(p);
+
+ if (fdp->fd_kqhashmask == 0) return NULL;
+
+ list = &fdp->fd_kqhash[KQ_HASH(id, fdp->fd_kqhashmask)];
+ SLIST_FOREACH(kqwl, list, kqwl_hashlink) {
+ if (kqwl->kqwl_dynamicid == id) {
+ struct kqueue *kq = (struct kqueue *)kqwl;
+
+ assert(kq->kq_state & KQ_DYNAMIC);
+ assert(kq->kq_state & KQ_WORKLOOP); /* for now */
+ return kq;
+ }
+ }
+ return NULL;
+}
+
+static inline void
+kqueue_release_last(struct proc *p, kqueue_t kqu)
+{
+ struct kqueue *kq = kqu.kq;
+ if (kq->kq_state & KQ_DYNAMIC) {
+ kqhash_lock(p);
+ if (kqueue_release(kq, KQUEUE_MIGHT_BE_LAST_REF)) {
+ thread_t cur_owner = kqworkloop_invalidate(kqu.kqwl);
+ kqueue_hash_remove(p, kq);
+ kqhash_unlock(p);
+ if (cur_owner) thread_deallocate(cur_owner);
+ kqueue_dealloc(kq);
+ } else {
+ kqhash_unlock(p);
+ }
+ }
+}
+
+/*
+ * kqworkloops_dealloc - rebalance retains on kqworkloops created with
+ * scheduling parameters
+ *
+ * Called with proc_fdlock held.
+ * Returns with it locked.
+ * Process is in such a state that it will not try to allocate
+ * any more knotes during this process (stopped for exit or exec).
+ */
+void
+kqworkloops_dealloc(proc_t p)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct kqlist *list;
+ struct kqworkloop *kqwl, *kqwln;
+ struct kqlist tofree;
+ int i;
+
+ if (!(fdp->fd_flags & FD_WORKLOOP)) {
+ return;
+ }
+
+ SLIST_INIT(&tofree);
+
+ kqhash_lock(p);
+ assert(fdp->fd_kqhashmask != 0);
+
+ for (i = 0; i <= (int)fdp->fd_kqhashmask; i++) {
+ list = &fdp->fd_kqhash[i];
+ SLIST_FOREACH_SAFE(kqwl, list, kqwl_hashlink, kqwln) {
+ /*
+ * kqworkloops that have scheduling parameters have an
+ * implicit retain from kqueue_workloop_ctl that needs
+ * to be balanced on process exit.
+ */
+ assert(kqwl->kqwl_params);
+ SLIST_REMOVE(list, kqwl, kqworkloop, kqwl_hashlink);
+ SLIST_INSERT_HEAD(&tofree, kqwl, kqwl_hashlink);
+ }
+ }
+
+ kqhash_unlock(p);
+
+ SLIST_FOREACH_SAFE(kqwl, &tofree, kqwl_hashlink, kqwln) {
+ struct kqueue *kq = (struct kqueue *)kqwl;
+ __assert_only bool released;
+ released = kqueue_release(kq, KQUEUE_MIGHT_BE_LAST_REF);
+ assert(released);
+ kqueue_dealloc(kq);
+ }
+}
+
+static struct kqueue *
+kevent_get_bound_kqworkloop(thread_t thread)
+{
+ struct uthread *ut = get_bsdthread_info(thread);
+ struct kqrequest *kqr = ut->uu_kqr_bound;
+
+ return kqr ? (struct kqueue *)kqr_kqworkloop(kqr) : NULL;
+}
+
+static int
+kevent_get_kq(struct proc *p, kqueue_id_t id, workq_threadreq_param_t *trp,
+ unsigned int flags, struct fileproc **fpp, int *fdp,
+ struct kqueue **kqp)
+{
+ struct filedesc *descp = p->p_fd;
+ struct fileproc *fp = NULL;
+ struct kqueue *kq = NULL;
+ int fd = 0;
+ int error = 0;
+ thread_t th = current_thread();
+
+ assert(!trp || (flags & KEVENT_FLAG_WORKLOOP));
+
+ /* Was the workloop flag passed? Then it is for sure only a workloop */
+ if (flags & KEVENT_FLAG_DYNAMIC_KQUEUE) {
+ assert(flags & KEVENT_FLAG_WORKLOOP);
+ assert(!trp || (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST));
+ kq = kevent_get_bound_kqworkloop(th);
+
+ /*
+ * when kevent_id_internal is called from within the
+ * kernel, and the passed 'id' value is '-1' then we
+ * look for the currently bound workloop kq.
+ */
+ if (id == (kqueue_id_t)-1 &&
+ (flags & KEVENT_FLAG_KERNEL) &&
+ (flags & KEVENT_FLAG_WORKLOOP)) {
+
+ if (!is_workqueue_thread(th) || !kq) {
+ return EINVAL;
+ }
+
+ kqueue_retain(kq);
+ goto out;
+ }
+
+ if (id == 0 || id == (kqueue_id_t)-1) {
+ return EINVAL;
+ }
+
+ /* try shortcut on kq lookup for bound threads */
+ if (kq != NULL && ((struct kqworkloop *)kq)->kqwl_dynamicid == id) {
+
+ if (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST) {
+ return EEXIST;
+ }
+
+ /* retain a reference while working with this kq. */
+ assert(kq->kq_state & KQ_DYNAMIC);
+ kqueue_retain(kq);
+ goto out;
+ }
+
+ /* look for the kq on the hash table */
+ kqhash_lock(p);
+ kq = kqueue_hash_lookup(p, id);
+ if (kq == NULL) {
+ kqhash_unlock(p);
+
+ if (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_EXIST) {
+ return ENOENT;
+ }
+
+ struct kqueue *alloc_kq;
+ alloc_kq = kqueue_alloc(p, flags);
+ if (!alloc_kq) {
+ return ENOMEM;
+ }
+
+ kqhash_lock(p);
+ kqueue_hash_init_if_needed(p);
+ kq = kqueue_hash_lookup(p, id);
+ if (kq == NULL) {
+ /* insert our new one */
+ kq = alloc_kq;
+ if (trp) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ kqwl->kqwl_params = trp->trp_value;
+ }
+ kqueue_hash_insert(p, id, kq);
+ kqhash_unlock(p);
+ } else if (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST) {
+ /* lost race and caller wants an error */
+ kqhash_unlock(p);
+ kqueue_release(alloc_kq, KQUEUE_MIGHT_BE_LAST_REF);
+ kqueue_dealloc(alloc_kq);
+ return EEXIST;
+ } else {
+ /* lost race, retain existing workloop */
+ kqueue_retain(kq);
+ kqhash_unlock(p);
+ kqueue_release(alloc_kq, KQUEUE_MIGHT_BE_LAST_REF);
+ kqueue_dealloc(alloc_kq);
+ }
+ } else {
+
+ if (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST) {
+ kqhash_unlock(p);
+ return EEXIST;
+ }
+
+ /* retain a reference while working with this kq. */
+ assert(kq->kq_state & KQ_DYNAMIC);
+ kqueue_retain(kq);
+ kqhash_unlock(p);
+ }
+
+ } else if (flags & KEVENT_FLAG_WORKQ) {
+ /* must already exist for bound threads. */
+ if (flags & KEVENT_FLAG_KERNEL) {
+ assert(descp->fd_wqkqueue != NULL);
+ }
+
+ /*
+ * use the private kq associated with the proc workq.
+ * Just being a thread within the process (and not
+ * being the exit/exec thread) is enough to hold a
+ * reference on this special kq.
+ */
+ kq = descp->fd_wqkqueue;
+ if (kq == NULL) {
+ struct kqueue *alloc_kq = kqueue_alloc(p, KEVENT_FLAG_WORKQ);
+ if (alloc_kq == NULL) {
+ return ENOMEM;
+ }
+
+ knhash_lock(p);
+ if (descp->fd_wqkqueue == NULL) {
+ kq = descp->fd_wqkqueue = alloc_kq;
+ knhash_unlock(p);
+ } else {
+ knhash_unlock(p);
+ kq = descp->fd_wqkqueue;
+ kqueue_dealloc(alloc_kq);
+ }
+ }
+ } else {
+ /* get a usecount for the kq itself */
+ fd = (int)id;
+ if ((error = fp_getfkq(p, fd, &fp, &kq)) != 0)
+ return (error);
+ }
+ if ((error = kevent_set_kq_mode(kq, flags)) != 0) {
+ /* drop the usecount */
+ if (fp != NULL)
+ fp_drop(p, fd, fp, 0);
+ return error;
+ }
+
+out:
+ *fpp = fp;
+ *fdp = fd;
+ *kqp = kq;
+
+ return error;
+}
+
+static void
+kevent_put_kq(
+ struct proc *p,
+ kqueue_id_t id,
+ struct fileproc *fp,
+ struct kqueue *kq)
+{
+ kqueue_release_last(p, kq);
+ if (fp != NULL) {
+ assert((kq->kq_state & KQ_WORKQ) == 0);
+ fp_drop(p, (int)id, fp, 0);
+ }
+}
+
+static uint64_t
+kevent_workloop_serial_no_copyin(proc_t p, uint64_t workloop_id)
+{
+ uint64_t serial_no = 0;
+ user_addr_t addr;
+ int rc;
+
+ if (workloop_id == 0 || p->p_dispatchqueue_serialno_offset == 0) {
+ return 0;
+ }
+ addr = (user_addr_t)(workloop_id + p->p_dispatchqueue_serialno_offset);
+
+ if (proc_is64bit(p)) {
+ rc = copyin(addr, (caddr_t)&serial_no, sizeof(serial_no));
+ } else {
+ uint32_t serial_no32 = 0;
+ rc = copyin(addr, (caddr_t)&serial_no32, sizeof(serial_no32));
+ serial_no = serial_no32;
+ }
+ return rc == 0 ? serial_no : 0;
+}
+
+int
+kevent_exit_on_workloop_ownership_leak(thread_t thread)
+{
+ proc_t p = current_proc();
+ struct filedesc *fdp = p->p_fd;
+ kqueue_id_t workloop_id = 0;
+ os_reason_t reason = OS_REASON_NULL;
+ mach_vm_address_t addr;
+ uint32_t reason_size;
+
+ kqhash_lock(p);
+ if (fdp->fd_kqhashmask > 0) {
+ for (uint32_t i = 0; i < fdp->fd_kqhashmask + 1; i++) {
+ struct kqworkloop *kqwl;
+
+ SLIST_FOREACH(kqwl, &fdp->fd_kqhash[i], kqwl_hashlink) {
+ struct kqueue *kq = &kqwl->kqwl_kqueue;
+ if ((kq->kq_state & KQ_DYNAMIC) && kqwl->kqwl_owner == thread) {
+ workloop_id = kqwl->kqwl_dynamicid;
+ break;
+ }
+ }
+ }
+ }
+ kqhash_unlock(p);
+
+ reason = os_reason_create(OS_REASON_LIBSYSTEM,
+ OS_REASON_LIBSYSTEM_CODE_WORKLOOP_OWNERSHIP_LEAK);
+ if (reason == OS_REASON_NULL) {
+ goto out;
+ }
+
+ reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
+ reason_size = 2 * sizeof(uint64_t);
+ reason_size = kcdata_estimate_required_buffer_size(2, reason_size);
+ if (os_reason_alloc_buffer(reason, reason_size) != 0) {
+ goto out;
+ }
+
+ if (workloop_id) {
+ struct kcdata_descriptor *kcd = &reason->osr_kcd_descriptor;
+
+ if (kcdata_get_memory_addr(kcd, EXIT_REASON_WORKLOOP_ID,
+ sizeof(workloop_id), &addr) == KERN_SUCCESS) {
+ kcdata_memcpy(kcd, addr, &workloop_id, sizeof(workloop_id));
+ }
+
+ uint64_t serial_no = kevent_workloop_serial_no_copyin(p, workloop_id);
+ if (serial_no && kcdata_get_memory_addr(kcd, EXIT_REASON_DISPATCH_QUEUE_NO,
+ sizeof(serial_no), &addr) == KERN_SUCCESS) {
+ kcdata_memcpy(kcd, addr, &serial_no, sizeof(serial_no));
+ }
+ }
+out:
+#if DEVELOPMENT || DEBUG
+ if (kevent_debug_flags() & KEVENT_PANIC_ON_WORKLOOP_OWNERSHIP_LEAK) {
+ panic("thread %p in task %p is leaked workloop 0x%016llx ownership",
+ thread, p->task, workloop_id);
+ }
+ psignal_try_thread_with_reason(p, thread, SIGABRT, reason);
+ return 0;
+#else
+ return exit_with_reason(p, W_EXITCODE(0, SIGKILL), (int *)NULL,
+ FALSE, FALSE, 0, reason);
+#endif
+}
+
+static inline boolean_t
+kevent_args_requesting_events(unsigned int flags, int nevents)
+{
+ return (!(flags & KEVENT_FLAG_ERROR_EVENTS) && nevents > 0);
+}
+
+static int
+kevent_internal(struct proc *p,
+ kqueue_id_t id, kqueue_id_t *id_out,
+ user_addr_t changelist, int nchanges,
+ user_addr_t ueventlist, int nevents,
+ user_addr_t data_out, uint64_t data_available,
+ unsigned int flags,
+ user_addr_t utimeout,
+ kqueue_continue_t continuation,
+ int32_t *retval)
+{
+ uthread_t ut;
+ struct kqueue *kq;
+ struct fileproc *fp = NULL;
+ int fd = 0;
+ struct kevent_internal_s kev;
+ int error, noutputs, register_rc;
+ bool needs_end_processing = false;
+ struct timeval atv;
+ user_size_t data_size;
+ user_size_t data_resid;
+ thread_t thread = current_thread();
+ KNOTE_LOCK_CTX(knlc);
+
+ /* Don't allow user-space threads to process output events from the workq kqs */
+ if (((flags & (KEVENT_FLAG_WORKQ | KEVENT_FLAG_KERNEL)) == KEVENT_FLAG_WORKQ) &&
+ kevent_args_requesting_events(flags, nevents))
+ return EINVAL;
+
+ if (flags & KEVENT_FLAG_PARKING) {
+ if (!kevent_args_requesting_events(flags, nevents) || id != (kqueue_id_t)-1)
+ return EINVAL;
+ }
+
+ /* restrict dynamic kqueue allocation to workloops (for now) */
+ if ((flags & (KEVENT_FLAG_DYNAMIC_KQUEUE | KEVENT_FLAG_WORKLOOP)) == KEVENT_FLAG_DYNAMIC_KQUEUE)
+ return EINVAL;
+
+ if ((flags & (KEVENT_FLAG_WORKLOOP)) && (flags & (KEVENT_FLAG_WORKQ)))
+ return EINVAL;
+
+ if (flags & (KEVENT_FLAG_DYNAMIC_KQ_MUST_EXIST | KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST)) {
+
+ /* allowed only on workloops when calling kevent_id from user-space */
+ if (!(flags & KEVENT_FLAG_WORKLOOP) || (flags & KEVENT_FLAG_KERNEL) || !(flags & KEVENT_FLAG_DYNAMIC_KQUEUE))
+ return EINVAL;
+ }
+
+ /* prepare to deal with stack-wise allocation of out events */
+ if (flags & KEVENT_FLAG_STACK_EVENTS) {
+ int scale = ((flags & KEVENT_FLAG_LEGACY32) ?
+ (IS_64BIT_PROCESS(p) ? sizeof(struct user64_kevent) :
+ sizeof(struct user32_kevent)) :
+ ((flags & KEVENT_FLAG_LEGACY64) ? sizeof(struct kevent64_s) :
+ sizeof(struct kevent_qos_s)));
+ ueventlist += nevents * scale;
+ }
+
+ /* convert timeout to absolute - if we have one (and not immediate) */
+ error = kevent_get_timeout(p, utimeout, flags, &atv);
+ if (error)
+ return error;
+
+ /* copyin initial value of data residual from data_available */
+ error = kevent_get_data_size(p, data_available, flags, &data_size);
+ if (error)
+ return error;
+
+ /* get the kq we are going to be working on */
+ error = kevent_get_kq(p, id, NULL, flags, &fp, &fd, &kq);
+#if CONFIG_WORKLOOP_DEBUG
+ ut = (uthread_t)get_bsdthread_info(thread);
+ UU_KEVENT_HISTORY_WRITE_ENTRY(ut, {
+ .uu_kqid = id,
+ .uu_kq = error ? NULL : kq,
+ .uu_error = error,
+ .uu_nchanges = nchanges,
+ .uu_nevents = nevents,
+ .uu_flags = flags,
+ });
+#endif // CONFIG_WORKLOOP_DEBUG
+ if (error)
+ return error;
+
+ /* only bound threads can receive events on workloops */
+ if (flags & KEVENT_FLAG_WORKLOOP) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ assert(kq->kq_state & KQ_WORKLOOP);
+
+ if (kevent_args_requesting_events(flags, nevents)) {
+ if (kq != kevent_get_bound_kqworkloop(thread)) {
+ error = EXDEV;
+ goto out;
+ }
+
+ kq_req_lock(kqwl);
+ /*
+ * Disable the R2K notification while doing a register, if the
+ * caller wants events too, we don't want the AST to be set if we
+ * will process these events soon.
+ */
+ kqr->kqr_state &= ~KQR_R2K_NOTIF_ARMED;
+ needs_end_processing = true;
+ kq_req_unlock(kq);
+ }
+
+ if (id_out) {
+ *id_out = kqwl->kqwl_dynamicid;
+ }
+
+ }
+
+ /* register all the change requests the user provided... */
+ noutputs = 0;
+ while (nchanges > 0 && error == 0) {
+ error = kevent_copyin(&changelist, &kev, p, flags);
+ if (error)
+ break;
+
+ /* Make sure user doesn't pass in any system flags */
+ kev.flags &= ~EV_SYSFLAGS;
+
+ register_rc = kevent_register(kq, &kev, &knlc);
+ if (register_rc & FILTER_REGISTER_WAIT) {
+ kqlock_held(kq);
+
+ // f_post_register_wait is meant to call a continuation and not to
+ // return, which is why we don't support FILTER_REGISTER_WAIT if
+ // KEVENT_FLAG_ERROR_EVENTS is not passed, or if the event that
+ // waits isn't the last.
+ //
+ // It is implementable, but not used by any userspace code at the
+ // moment, so for now return ENOTSUP if someone tries to do it.
+ if (nchanges == 1 && nevents >= 1 && (flags & KEVENT_FLAG_ERROR_EVENTS)) {
+ struct _kevent_register *cont_args;
+ /* store the continuation/completion data in the uthread */
+ ut = (uthread_t)get_bsdthread_info(thread);
+ cont_args = &ut->uu_save.uus_kevent_register;
+ cont_args->kev = kev;
+ cont_args->kq = kq;
+ cont_args->fp = fp;
+ cont_args->fd = fd;
+ cont_args->ueventlist = ueventlist;
+ cont_args->flags = flags;
+ cont_args->retval = retval;
+ cont_args->eventcount = nevents;
+ cont_args->eventout = noutputs;
+ knote_fops(cont_args->knote)->f_post_register_wait(ut, &knlc, cont_args);
+ panic("f_post_register_wait returned (kev: %p)", &kev);
+ }
+
+ kev.flags |= EV_ERROR;
+ kev.data = ENOTSUP;
+ knote_unlock(kq, knlc.knlc_knote, &knlc, KNOTE_KQ_UNLOCK);
+ }
+
+ // keep in sync with kevent_register_wait_return()
+ if (nevents > 0 && (kev.flags & (EV_ERROR|EV_RECEIPT))) {
+ if ((kev.flags & EV_ERROR) == 0) {
+ kev.flags |= EV_ERROR;
+ kev.data = 0;
+ }
+ error = kevent_copyout(&kev, &ueventlist, p, flags);
+ if (error == 0) {
+ nevents--;
+ noutputs++;
+ }
+ } else if (kev.flags & EV_ERROR) {
+ error = kev.data;
+ }
+ nchanges--;
+ }
+
+ /* short-circuit the scan if we only want error events */
+ if (flags & KEVENT_FLAG_ERROR_EVENTS)
+ nevents = 0;
+
+ /* process pending events */
+ if (nevents > 0 && noutputs == 0 && error == 0) {
+ struct _kevent *cont_args;
+ /* store the continuation/completion data in the uthread */
+ ut = (uthread_t)get_bsdthread_info(thread);
+ cont_args = &ut->uu_save.uus_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->data_available = data_available;
+ cont_args->process_data.fp_fd = (int)id;
+ cont_args->process_data.fp_flags = flags;
+ cont_args->process_data.fp_data_out = data_out;
+ cont_args->process_data.fp_data_size = data_size;
+ cont_args->process_data.fp_data_resid = data_size;
+
+ /*
+ * kqworkloop_end_processing() will happen at the end of kqueue_scan()
+ */
+ needs_end_processing = false;
+
+ error = kqueue_scan(kq, kevent_callback,
+ continuation, cont_args,
+ &cont_args->process_data,
+ &atv, p);
+
+ /* process remaining outputs */
+ noutputs = cont_args->eventout;
+ data_resid = cont_args->process_data.fp_data_resid;
+
+ /* copyout residual data size value (if it needs to be copied out) */
+ /* don't abandon other output just because of residual copyout failures */
+ if (error == 0 && data_available && data_resid != data_size) {
+ (void)kevent_put_data_size(p, data_available, flags, data_resid);
+ }
+ }
+
+out:
+ if (__improbable(needs_end_processing)) {
+ /*
+ * If we didn't through kqworkloop_end_processing(),
+ * we need to do it here.
+ */
+ kqlock(kq);
+ kqworkloop_end_processing((struct kqworkloop *)kq, 0, 0);
+ kqunlock(kq);
+ }
+ kevent_put_kq(p, id, fp, kq);
+
+ /* don't restart after signals... */
+ if (error == ERESTART)
+ error = EINTR;
+ else if (error == EWOULDBLOCK)
+ error = 0;
+ if (error == 0)
+ *retval = noutputs;
+ 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_internal_s *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(),
+ cont_args->process_data.fp_flags);
+
+ /*
+ * 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 256-byte string buffer
+ */
+
+char *
+kevent_description(struct kevent_internal_s *kevp, char *s, size_t n)
+{
+ snprintf(s, n,
+ "kevent="
+ "{.ident=%#llx, .filter=%d, .flags=%#x, .udata=%#llx, .fflags=%#x, .data=%#llx, .ext[0]=%#llx, .ext[1]=%#llx}",
+ kevp->ident,
+ kevp->filter,
+ kevp->flags,
+ kevp->udata,
+ kevp->fflags,
+ kevp->data,
+ kevp->ext[0],
+ kevp->ext[1] );
+
+ return (s);
+}
+
+static int
+kevent_register_validate_priority(struct kqueue *kq, struct knote *kn,
+ struct kevent_internal_s *kev)
+{
+ /* We don't care about the priority of a disabled or deleted knote */
+ if (kev->flags & (EV_DISABLE | EV_DELETE)) {
+ return 0;
+ }
+
+ if (kq->kq_state & KQ_WORKLOOP) {
+ /*
+ * Workloops need valid priorities with a QOS (excluding manager) for
+ * any enabled knote.
+ *
+ * When it is pre-existing, just make sure it has a valid QoS as
+ * kevent_register() will not use the incoming priority (filters who do
+ * have the responsibility to validate it again, see filt_wltouch).
+ *
+ * If the knote is being made, validate the incoming priority.
+ */
+ if (!_pthread_priority_thread_qos(kn ? kn->kn_qos : kev->qos)) {
+ return ERANGE;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Prepare a filter for waiting after register.
+ *
+ * The f_post_register_wait hook will be called later by kevent_register()
+ * and should call kevent_register_wait_block()
+ */
+static int
+kevent_register_wait_prepare(struct knote *kn, struct kevent_internal_s *kev)
+{
+ thread_t thread = current_thread();
+ struct uthread *uth = get_bsdthread_info(thread);
+
+ assert(knote_fops(kn)->f_extended_codes);
+
+ if (kn->kn_hook == NULL) {
+ thread_reference(thread);
+ kn->kn_hook = thread;
+ } else if (kn->kn_hook != thread) {
+ /*
+ * kn_hook may be set from a previous aborted wait
+ * However, it has to be from the same thread.
+ */
+ kev->flags |= EV_ERROR;
+ kev->data = EXDEV;
+ return 0;
+ }
+
+ uth->uu_save.uus_kevent_register.knote = kn;
+ return FILTER_REGISTER_WAIT;
+}
+
+/*
+ * Cleanup a kevent_register_wait_prepare() effect for threads that have been
+ * aborted instead of properly woken up with thread_wakeup_thread().
+ */
+static void
+kevent_register_wait_cleanup(struct knote *kn)
+{
+ thread_t thread = kn->kn_hook;
+ kn->kn_hook = NULL;
+ thread_deallocate(thread);
+}
+
+/*
+ * Must be called at the end of a f_post_register_wait call from a filter.
+ */
+static void
+kevent_register_wait_block(struct turnstile *ts, thread_t thread,
+ struct knote_lock_ctx *knlc, thread_continue_t cont,
+ struct _kevent_register *cont_args)
+{
+ knote_unlock(cont_args->kq, cont_args->knote, knlc, KNOTE_KQ_UNLOCK);
+ turnstile_update_inheritor_complete(ts, TURNSTILE_INTERLOCK_NOT_HELD);
+ cont_args->handoff_thread = thread;
+ thread_handoff_parameter(thread, cont, cont_args);
+}
+
+/*
+ * Called by Filters using a f_post_register_wait to return from their wait.
+ */
+static void
+kevent_register_wait_return(struct _kevent_register *cont_args)
+{
+ struct kqueue *kq = cont_args->kq;
+ proc_t p = kq->kq_p;
+ struct kevent_internal_s *kev = &cont_args->kev;
+ int error = 0;
+
+ if (cont_args->handoff_thread) {
+ thread_deallocate(cont_args->handoff_thread);
+ }
+
+ if (kev->flags & (EV_ERROR|EV_RECEIPT)) {
+ if ((kev->flags & EV_ERROR) == 0) {
+ kev->flags |= EV_ERROR;
+ kev->data = 0;
+ }
+ error = kevent_copyout(kev, &cont_args->ueventlist, p, cont_args->flags);
+ if (error == 0) cont_args->eventout++;
+ }
+
+ kevent_put_kq(p, cont_args->fd, cont_args->fp, kq);
+ if (error == 0) {
+ *cont_args->retval = cont_args->eventout;
+ }
+ unix_syscall_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_internal_s *kev,
+ struct knote_lock_ctx *knlc)
+{
+ struct proc *p = kq->kq_p;
+ const struct filterops *fops;
+ struct knote *kn = NULL;
+ int result = 0, error = 0;
+ unsigned short kev_flags = kev->flags;
+
+ if (kev->filter < 0) {
+ if (kev->filter + EVFILT_SYSCOUNT < 0) {
+ error = EINVAL;
+ goto out;
+ }
+ fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
+ } else {
+ error = EINVAL;
+ goto out;
+ }
+
+ /* restrict EV_VANISHED to adding udata-specific dispatch kevents */
+ if ((kev->flags & EV_VANISHED) &&
+ (kev->flags & (EV_ADD | EV_DISPATCH2)) != (EV_ADD | EV_DISPATCH2)) {
+ error = EINVAL;
+ goto out;
+ }
+
+ /* Simplify the flags - delete and disable overrule */
+ if (kev->flags & EV_DELETE)
+ kev->flags &= ~EV_ADD;
+ if (kev->flags & EV_DISABLE)
+ kev->flags &= ~EV_ENABLE;
+
+ if (kq->kq_state & KQ_WORKLOOP) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_REGISTER),
+ ((struct kqworkloop *)kq)->kqwl_dynamicid,
+ kev->udata, kev->flags, kev->filter);
+ } else if (kq->kq_state & KQ_WORKQ) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_REGISTER),
+ 0, kev->udata, kev->flags, kev->filter);
+ } else {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_REGISTER),
+ VM_KERNEL_UNSLIDE_OR_PERM(kq),
+ kev->udata, kev->flags, kev->filter);
+ }
+
+restart:
+ /* find the matching knote from the fd tables/hashes */
+ kn = kq_find_knote_and_kq_lock(kq, kev, fops->f_isfd, p);
+ error = kevent_register_validate_priority(kq, kn, kev);
+ result = 0;
+ if (error) {
+ goto out;
+ }
+
+ if (kn == NULL && (kev->flags & EV_ADD) == 0) {
+ /*
+ * No knote found, EV_ADD wasn't specified
+ */
+
+ if ((kev_flags & EV_ADD) && (kev_flags & EV_DELETE) &&
+ (kq->kq_state & KQ_WORKLOOP)) {
+ /*
+ * For workloops, understand EV_ADD|EV_DELETE as a "soft" delete
+ * that doesn't care about ENOENT, so just pretend the deletion
+ * happened.
+ */
+ } else {
+ error = ENOENT;
+ }
+ goto out;
+
+ } else if (kn == NULL) {
+ /*
+ * No knote found, need to attach a new one (attach)
+ */
+
+ struct fileproc *knote_fp = NULL;
+
+ /* grab a file reference for the new knote */
+ if (fops->f_isfd) {
+ if ((error = fp_lookup(p, kev->ident, &knote_fp, 0)) != 0) {
+ goto out;
+ }
+ }
+
+ kn = knote_alloc();
+ if (kn == NULL) {
+ error = ENOMEM;
+ if (knote_fp != NULL)
+ fp_drop(p, kev->ident, knote_fp, 0);
+ goto out;
+ }
+
+ kn->kn_fp = knote_fp;
+ kn->kn_kq_packed = (intptr_t)(struct kqueue *)kq;
+ kqueue_retain(kq); /* retain a kq ref */
+ kn->kn_filtid = ~kev->filter;
+ kn->kn_status = KN_ATTACHING | KN_ATTACHED;
+
+ /* was vanish support requested */
+ if (kev->flags & EV_VANISHED) {
+ kev->flags &= ~EV_VANISHED;
+ kn->kn_status |= KN_REQVANISH;
+ }
+
+ /* snapshot matching/dispatching protcol flags into knote */
+ if (kev->flags & EV_DISPATCH)
+ kn->kn_status |= KN_DISPATCH;
+ if (kev->flags & EV_UDATA_SPECIFIC)
+ kn->kn_status |= KN_UDATA_SPECIFIC;
+ if (kev->flags & EV_DISABLE)
+ kn->kn_status |= KN_DISABLED;
+
+ /*
+ * copy the kevent state into knote
+ * protocol is that fflags and data
+ * are saved off, and cleared before
+ * calling the attach routine.
+ */
+ kn->kn_kevent = *kev;
+ kn->kn_sfflags = kev->fflags;
+ kn->kn_sdata = kev->data;
+ kn->kn_fflags = 0;
+ kn->kn_data = 0;
+ knote_reset_priority(kn, kev->qos);
+
+ /* Add the knote for lookup thru the fd table */
+ error = kq_add_knote(kq, kn, knlc, p);
+ if (error) {
+ (void)kqueue_release(kq, KQUEUE_CANT_BE_LAST_REF);
+ knote_free(kn);
+ if (knote_fp != NULL)
+ fp_drop(p, kev->ident, knote_fp, 0);
+
+ if (error == ERESTART) {
+ goto restart;
+ }
+ goto out;
+ }
+
+ /* fp reference count now applies to knote */
+
+ /*
+ * we can't use filter_call() because f_attach can change the filter ops
+ * for a filter that supports f_extended_codes, so we need to reload
+ * knote_fops() and not use `fops`.
+ */
+ result = fops->f_attach(kn, kev);
+ if (result && !knote_fops(kn)->f_extended_codes) {
+ result = FILTER_ACTIVE;
+ }
+
+ kqlock(kq);
+
+ if (kn->kn_flags & EV_ERROR) {
+ /*
+ * Failed to attach correctly, so drop.
+ */
+ kn->kn_status &= ~(KN_ATTACHED | KN_ATTACHING);
+ error = kn->kn_data;
+ knote_drop(kq, kn, knlc);
+ result = 0;
+ goto out;
+ }
+
+ /*
+ * end "attaching" phase - now just attached
+ *
+ * Mark the thread request overcommit, if appropos
+ *
+ * If the attach routine indicated that an
+ * event is already fired, activate the knote.
+ */
+ kn->kn_status &= ~KN_ATTACHING;
+ knote_set_qos_overcommit(kn);
+
+ if (result & FILTER_ACTIVE) {
+ if (result & FILTER_ADJUST_EVENT_QOS_BIT)
+ knote_adjust_qos(kq, kn, result);
+ knote_activate(kn);
+ }
+
+ } else if (!knote_lock(kq, kn, knlc, KNOTE_KQ_LOCK_ON_SUCCESS)) {
+
+ /*
+ * The knote was dropped while we were waiting for the lock,
+ * we need to re-evaluate entirely
+ */
+
+ goto restart;
+
+ } else if (kev->flags & EV_DELETE) {
+ /*
+ * Deletion of a knote (drop)
+ *
+ * If the filter wants to filter drop events, let it do so.
+ *
+ * defer-delete: when trying to delete a disabled EV_DISPATCH2 knote,
+ * we must wait for the knote to be re-enabled (unless it is being
+ * re-enabled atomically here).
+ */
+
+ if (knote_fops(kn)->f_allow_drop) {
+ bool drop;
+
+ kqunlock(kq);
+ drop = knote_fops(kn)->f_allow_drop(kn, kev);
+ kqlock(kq);
+
+ if (!drop) goto out_unlock;
+ }
+
+ if ((kev->flags & EV_ENABLE) == 0 &&
+ (kn->kn_status & (KN_DISPATCH2 | KN_DISABLED)) ==
+ (KN_DISPATCH2 | KN_DISABLED)) {
+ kn->kn_status |= KN_DEFERDELETE;
+ error = EINPROGRESS;
+ goto out_unlock;
+ }
+
+ knote_drop(kq, kn, knlc);
+ goto out;
+
+ } else {
+ /*
+ * Regular update of a knote (touch)
+ *
+ * Call touch routine to notify filter of changes in filter values
+ * (and to re-determine if any events are fired).
+ *
+ * If the knote is in defer-delete, avoid calling the filter touch
+ * routine (it has delivered its last event already).
+ *
+ * If the touch routine had no failure,
+ * apply the requested side effects to the knote.
+ */
+
+ if (kn->kn_status & (KN_DEFERDELETE | KN_VANISHED)) {
+ if (kev->flags & EV_ENABLE) {
+ result = FILTER_ACTIVE;
+ }
+ } else {
+ kqunlock(kq);
+ result = filter_call(knote_fops(kn), f_touch(kn, kev));
+ kqlock(kq);
+ }
+
+ if (kev->flags & EV_ERROR) {
+ result = 0;
+ } else {
+ /* accept new kevent state */
+ if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0)
+ kn->kn_udata = kev->udata;
+ if (kev->flags & EV_DISABLE)
+ knote_disable(kn);
+ if (result & (FILTER_UPDATE_REQ_QOS | FILTER_ADJUST_EVENT_QOS_BIT))
+ knote_dequeue(kn);
+ if ((result & FILTER_UPDATE_REQ_QOS) &&
+ kev->qos && kev->qos != kn->kn_qos) {
+ knote_reset_priority(kn, kev->qos);
+ }
+ if (result & FILTER_ACTIVE) {
+ thread_qos_t qos;
+ if (result & FILTER_ADJUST_EVENT_QOS_BIT) {
+ if (knote_should_apply_qos_override(kq, kn, result, &qos)) {
+ knote_apply_qos_override(kn, qos);
+ }
+ }
+ knote_activate(kn);
+ }
+ if (result & (FILTER_UPDATE_REQ_QOS | FILTER_ADJUST_EVENT_QOS_BIT)) {
+ if (knote_enqueue(kn) && (kn->kn_status & KN_ACTIVE)) {
+ knote_wakeup(kn);
+ }
+ }
+ if (kev->flags & EV_ENABLE)
+ knote_enable(kn);
+ }
+ }
+
+out_unlock:
+ if ((result & FILTER_REGISTER_WAIT) == 0) {
+ /*
+ * When the filter asked for a post-register wait,
+ * we leave the knote and kqueue locked for kevent_register()
+ * to call the filter's f_post_register_wait hook.
+ */
+ knote_unlock(kq, kn, knlc, KNOTE_KQ_UNLOCK);
+ }
+
+out:
+ /* output local errors through the kevent */
+ if (error) {
+ kev->flags |= EV_ERROR;
+ kev->data = error;
+ }
+ return result;
+}
+
+/*
+ * 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, we will have taken
+ * a copy of the state under the filter lock. We use that
+ * snapshot to dispatch the knote for future processing (or
+ * not, if this was a lost event).
+ *
+ * Our caller assures us that nobody else can be processing
+ * events from this knote during the whole operation. But
+ * others can be touching or posting events to the knote
+ * interspersed with our processing it.
+ *
+ * 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 *callback_data,
+ struct filt_process_s *process_data)
+{
+ struct kevent_internal_s kev;
+ struct kqueue *kq = knote_get_kq(kn);
+ KNOTE_LOCK_CTX(knlc);
+ int result = FILTER_ACTIVE;
+ int error = 0;
+ bool drop = false;
+
+ bzero(&kev, sizeof(kev));
+
+ /*
+ * Must be active or stayactive
+ * Must be queued and not disabled/suppressed
+ */
+ assert(kn->kn_status & KN_QUEUED);
+ assert(kn->kn_status & (KN_ACTIVE|KN_STAYACTIVE));
+ assert(!(kn->kn_status & (KN_DISABLED|KN_SUPPRESSED|KN_DROPPING)));
+
+ if (kq->kq_state & KQ_WORKLOOP) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS),
+ ((struct kqworkloop *)kq)->kqwl_dynamicid,
+ kn->kn_udata, kn->kn_status | (kn->kn_id << 32),
+ kn->kn_filtid);
+ } else if (kq->kq_state & KQ_WORKQ) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_PROCESS),
+ 0, kn->kn_udata, kn->kn_status | (kn->kn_id << 32),
+ kn->kn_filtid);
+ } else {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS),
+ VM_KERNEL_UNSLIDE_OR_PERM(kq), kn->kn_udata,
+ kn->kn_status | (kn->kn_id << 32), kn->kn_filtid);
+ }
+
+ if ((kn->kn_status & KN_DROPPING) ||
+ !knote_lock(kq, kn, &knlc, KNOTE_KQ_LOCK_ALWAYS)) {
+ /*
+ * When the knote is dropping or has dropped,
+ * then there's nothing we want to process.
+ */
+ return EJUSTRETURN;
+ }
+
+ /*
+ * For deferred-drop or vanished events, we just create a fake
+ * event to acknowledge end-of-life. Otherwise, we call the
+ * filter's process routine to snapshot the kevent state under
+ * the filter's locking protocol.
+ *
+ * suppress knotes to avoid returning the same event multiple times in
+ * a single call.
+ */
+ knote_suppress(kn);
+
+ if (kn->kn_status & (KN_DEFERDELETE | KN_VANISHED)) {
+ /* create fake event */
+ kev.filter = kn->kn_filter;
+ kev.ident = kn->kn_id;
+ kev.flags = (kn->kn_status & KN_DEFERDELETE) ? EV_DELETE : EV_VANISHED;
+ kev.flags |= (EV_DISPATCH2 | EV_ONESHOT);
+ kev.udata = kn->kn_udata;
+ } else {
+ /* deactivate - so new activations indicate a wakeup */
+ knote_deactivate(kn);
+
+ kqunlock(kq);
+ result = filter_call(knote_fops(kn), f_process(kn, process_data, &kev));
+ kqlock(kq);
+ }
+
+ /*
+ * Determine how to dispatch the knote for future event handling.
+ * not-fired: just return (do not callout, leave deactivated).
+ * One-shot: If dispatch2, enter deferred-delete mode (unless this is
+ * is the deferred delete event delivery itself). Otherwise,
+ * drop it.
+ * Dispatch: don't clear state, just mark it disabled.
+ * Cleared: just leave it deactivated.
+ * Others: re-activate as there may be more events to handle.
+ * This will not wake up more handlers right now, but
+ * at the completion of handling events it may trigger
+ * more handler threads (TODO: optimize based on more than
+ * just this one event being detected by the filter).
+ */
+ if ((result & FILTER_ACTIVE) == 0) {
+ if ((kn->kn_status & (KN_ACTIVE | KN_STAYACTIVE)) == 0) {
+ /*
+ * Stay active knotes should not be unsuppressed or we'd create an
+ * infinite loop.
+ *
+ * Some knotes (like EVFILT_WORKLOOP) can be reactivated from
+ * within f_process() but that doesn't necessarily make them
+ * ready to process, so we should leave them be.
+ *
+ * For other knotes, since we will not return an event,
+ * there's no point keeping the knote suppressed.
+ */
+ knote_unsuppress(kn);
+ }
+ knote_unlock(kq, kn, &knlc, KNOTE_KQ_LOCK_ALWAYS);
+ return EJUSTRETURN;
+ }
+
+ if (result & FILTER_ADJUST_EVENT_QOS_BIT)
+ knote_adjust_qos(kq, kn, result);
+ kev.qos = _pthread_priority_combine(kn->kn_qos, kn->kn_qos_override);
+
+ if (kev.flags & EV_ONESHOT) {
+ if ((kn->kn_status & (KN_DISPATCH2 | KN_DEFERDELETE)) == KN_DISPATCH2) {
+ /* defer dropping non-delete oneshot dispatch2 events */
+ kn->kn_status |= KN_DEFERDELETE;
+ knote_disable(kn);
+ } else {
+ drop = true;
+ }
+ } else if (kn->kn_status & KN_DISPATCH) {
+ /* disable all dispatch knotes */
+ knote_disable(kn);
+ } else if ((kev.flags & EV_CLEAR) == 0) {
+ /* re-activate in case there are more events */
+ knote_activate(kn);
+ }
+
+ /*
+ * callback to handle each event as we find it.
+ * If we have to detach and drop the knote, do
+ * it while we have the kq unlocked.
+ */
+ if (drop) {
+ knote_drop(kq, kn, &knlc);
+ } else {
+ knote_unlock(kq, kn, &knlc, KNOTE_KQ_UNLOCK);
+ }
+
+ if (kev.flags & EV_VANISHED) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KNOTE_VANISHED),
+ kev.ident, kn->kn_udata, kn->kn_status | (kn->kn_id << 32),
+ kn->kn_filtid);
+ }
+
+ error = (callback)(kq, &kev, callback_data);
+ kqlock(kq);
+ return error;
+}
+
+/*
+ * Returns -1 if the kqueue was unbound and processing should not happen
+ */
+#define KQWQAE_BEGIN_PROCESSING 1
+#define KQWQAE_END_PROCESSING 2
+#define KQWQAE_UNBIND 3
+static int
+kqworkq_acknowledge_events(struct kqworkq *kqwq, struct kqrequest *kqr,
+ int kevent_flags, int kqwqae_op)
+{
+ thread_qos_t old_override = THREAD_QOS_UNSPECIFIED;
+ thread_t thread = kqr->kqr_thread;
+ struct knote *kn;
+ int rc = 0;
+ bool seen_stayactive = false, unbind;
+
+ kqlock_held(&kqwq->kqwq_kqueue);
+
+ if (!TAILQ_EMPTY(&kqr->kqr_suppressed)) {
+ /*
+ * Return suppressed knotes to their original state.
+ * For workq kqueues, suppressed ones that are still
+ * truly active (not just forced into the queue) will
+ * set flags we check below to see if anything got
+ * woken up.
+ */
+ while ((kn = TAILQ_FIRST(&kqr->kqr_suppressed)) != NULL) {
+ assert(kn->kn_status & KN_SUPPRESSED);
+ knote_unsuppress(kn);
+ if (kn->kn_status & KN_STAYACTIVE) {
+ seen_stayactive = true;
+ }
+ }
+ }
+
+ kq_req_lock(kqwq);
+
+#if DEBUG || DEVELOPMENT
+ thread_t self = current_thread();
+ struct uthread *ut = get_bsdthread_info(self);
+
+ assert(kqr->kqr_state & KQR_THREQUESTED);
+ assert(kqr->kqr_thread == self);
+ assert(ut->uu_kqr_bound == kqr);
+#endif // DEBUG || DEVELOPMENT
+
+ if (kqwqae_op == KQWQAE_UNBIND) {
+ unbind = true;
+ } else if ((kevent_flags & KEVENT_FLAG_PARKING) == 0) {
+ unbind = false;
+ } else if (kqwqae_op == KQWQAE_BEGIN_PROCESSING && seen_stayactive) {
+ /*
+ * When we unsuppress stayactive knotes, for the kind that are hooked
+ * through select, we need to process once before we can assert there's
+ * no event pending. Hence we can't unbind during BEGIN PROCESSING.
+ */
+ unbind = false;
+ } else {
+ unbind = ((kqr->kqr_state & KQR_WAKEUP) == 0);
+ }
+ if (unbind) {
+ old_override = kqworkq_unbind_locked(kqwq, kqr, thread);
+ rc = -1;
+ /*
+ * request a new thread if we didn't process the whole queue or real events
+ * have happened (not just putting stay-active events back).
+ */
+ if (kqr->kqr_state & KQR_WAKEUP) {
+ kqueue_threadreq_initiate(&kqwq->kqwq_kqueue, kqr,
+ kqr->kqr_qos_index, 0);
+ }
+ }
+
+ if (rc == 0) {
+ /*
+ * Reset wakeup bit to notice events firing while we are processing,
+ * as we cannot rely on the bucket queue emptiness because of stay
+ * active knotes.
+ */
+ kqr->kqr_state &= ~KQR_WAKEUP;
+ }
+
+ kq_req_unlock(kqwq);
+
+ if (old_override) {
+ thread_drop_ipc_override(thread);
+ }
+
+ return rc;
+}
+
+/*
+ * 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
+kqworkq_begin_processing(struct kqworkq *kqwq, struct kqrequest *kqr,
+ int kevent_flags)
+{
+ int rc = 0;
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_PROCESS_BEGIN) | DBG_FUNC_START,
+ 0, kqr->kqr_qos_index);
+
+ rc = kqworkq_acknowledge_events(kqwq, kqr, kevent_flags,
+ KQWQAE_BEGIN_PROCESSING);
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_PROCESS_BEGIN) | DBG_FUNC_END,
+ thread_tid(kqr->kqr_thread), kqr->kqr_state);
+
+ return rc;
+}
+
+static inline bool
+kqworkloop_is_processing_on_current_thread(struct kqworkloop *kqwl)
+{
+ struct kqueue *kq = &kqwl->kqwl_kqueue;
+
+ kqlock_held(kq);
+
+ if (kq->kq_state & KQ_PROCESSING) {
+ /*
+ * KQ_PROCESSING is unset with the kqlock held, and the kqr thread is
+ * never modified while KQ_PROCESSING is set, meaning that peeking at
+ * its value is safe from this context.
+ */
+ return kqwl->kqwl_request.kqr_thread == current_thread();
+ }
+ return false;
+}
+
+static thread_qos_t
+kqworkloop_acknowledge_events(struct kqworkloop *kqwl)
+{
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ kq_index_t qos = THREAD_QOS_UNSPECIFIED;
+ struct knote *kn, *tmp;
+
+ kqlock_held(&kqwl->kqwl_kqueue);
+
+ TAILQ_FOREACH_SAFE(kn, &kqr->kqr_suppressed, kn_tqe, tmp) {
+ /*
+ * If a knote that can adjust QoS is disabled because of the automatic
+ * behavior of EV_DISPATCH, the knotes should stay suppressed so that
+ * further overrides keep pushing.
+ */
+ if (knote_fops(kn)->f_adjusts_qos && (kn->kn_status & KN_DISABLED) &&
+ (kn->kn_status & (KN_STAYACTIVE | KN_DROPPING)) == 0 &&
+ (kn->kn_flags & (EV_DISPATCH | EV_DISABLE)) == EV_DISPATCH) {
+ qos = MAX(qos, knote_get_qos_override_index(kn));
+ continue;
+ }
+ knote_unsuppress(kn);
+ }
+
+ return qos;
+}
+
+static int
+kqworkloop_begin_processing(struct kqworkloop *kqwl, unsigned int kevent_flags)
+{
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ struct kqueue *kq = &kqwl->kqwl_kqueue;
+ thread_qos_t old_override = THREAD_QOS_UNSPECIFIED, qos_override;
+ thread_t thread = kqr->kqr_thread;
+ int rc = 0, op = KQWL_UTQ_NONE;
+
+ kqlock_held(kq);
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_BEGIN) | DBG_FUNC_START,
+ kqwl->kqwl_dynamicid, 0, 0);
+
+ /* nobody else should still be processing */
+ assert((kq->kq_state & KQ_PROCESSING) == 0);
+
+ kq->kq_state |= KQ_PROCESSING;
+
+ if (!TAILQ_EMPTY(&kqr->kqr_suppressed)) {
+ op = KQWL_UTQ_RESET_WAKEUP_OVERRIDE;
+ }
+
+ if (kevent_flags & KEVENT_FLAG_PARKING) {
+ /*
+ * When "parking" we want to process events and if no events are found
+ * unbind.
+ *
+ * However, non overcommit threads sometimes park even when they have
+ * more work so that the pool can narrow. For these, we need to unbind
+ * early, so that calling kqworkloop_update_threads_qos() can ask the
+ * workqueue subsystem whether the thread should park despite having
+ * pending events.
+ */
+ if (kqr->kqr_state & KQR_THOVERCOMMIT) {
+ op = KQWL_UTQ_PARKING;
+ } else {
+ op = KQWL_UTQ_UNBINDING;
+ }
+ }
+ if (op == KQWL_UTQ_NONE) {
+ goto done;
+ }
+
+ qos_override = kqworkloop_acknowledge_events(kqwl);
+
+ kq_req_lock(kqwl);
+
+ if (op == KQWL_UTQ_UNBINDING) {
+ old_override = kqworkloop_unbind_locked(kqwl, thread);
+ (void)kqueue_release(kqwl, KQUEUE_CANT_BE_LAST_REF);
+ }
+ kqworkloop_update_threads_qos(kqwl, op, qos_override);
+ if (op == KQWL_UTQ_PARKING) {
+ if (!TAILQ_EMPTY(&kqwl->kqwl_queue[KQWL_BUCKET_STAYACTIVE])) {
+ /*
+ * We cannot trust KQR_WAKEUP when looking at stay active knotes.
+ * We need to process once, and kqworkloop_end_processing will
+ * handle the unbind.
+ */
+ } else if ((kqr->kqr_state & KQR_WAKEUP) == 0 || kqwl->kqwl_owner) {
+ old_override = kqworkloop_unbind_locked(kqwl, thread);
+ (void)kqueue_release(kqwl, KQUEUE_CANT_BE_LAST_REF);
+ rc = -1;
+ }
+ } else if (op == KQWL_UTQ_UNBINDING) {
+ if (kqr->kqr_thread == thread) {
+ /*
+ * The thread request fired again, passed the admission check and
+ * got bound to the current thread again.
+ */
+ } else {
+ rc = -1;
+ }
+ }
+
+ if (rc == 0) {
+ /*
+ * Reset wakeup bit to notice stay active events firing while we are
+ * processing, as we cannot rely on the stayactive bucket emptiness.
+ */
+ kqr->kqr_wakeup_indexes &= ~KQWL_STAYACTIVE_FIRED_BIT;
+ } else {
+ kq->kq_state &= ~KQ_PROCESSING;
+ }
+
+ kq_req_unlock(kqwl);
+
+ if (old_override) {
+ thread_drop_ipc_override(thread);
+ }
+
+done:
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_BEGIN) | DBG_FUNC_END,
+ kqwl->kqwl_dynamicid, 0, 0);
+
+ return rc;
+}
+
+/*
+ * 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.
+ * May block.
+ */
+static int
+kqfile_begin_processing(struct kqueue *kq)
+{
+ struct kqtailq *suppressq;
+
+ kqlock_held(kq);
+
+ assert((kq->kq_state & (KQ_WORKQ | KQ_WORKLOOP)) == 0);
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_BEGIN) | DBG_FUNC_START,
+ VM_KERNEL_UNSLIDE_OR_PERM(kq), 0);
+
+ /* wait to become the exclusive processing thread */
+ for (;;) {
+ if (kq->kq_state & KQ_DRAIN) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_BEGIN) | DBG_FUNC_END,
+ VM_KERNEL_UNSLIDE_OR_PERM(kq), 2);
+ return -1;
+ }
+
+ if ((kq->kq_state & KQ_PROCESSING) == 0)
+ break;
+
+ /* if someone else is processing the queue, wait */
+ kq->kq_state |= KQ_PROCWAIT;
+ suppressq = kqueue_get_suppressed_queue(kq, NULL);
+ waitq_assert_wait64((struct waitq *)&kq->kq_wqs,
+ CAST_EVENT64_T(suppressq), THREAD_UNINT | THREAD_WAIT_NOREPORT,
+ TIMEOUT_WAIT_FOREVER);
+
+ kqunlock(kq);
+ thread_block(THREAD_CONTINUE_NULL);
+ kqlock(kq);
+ }
+
+ /* Nobody else processing */
+
+ /* clear pre-posts and KQ_WAKEUP now, in case we bail early */
+ waitq_set_clear_preposts(&kq->kq_wqs);
+ kq->kq_state &= ~KQ_WAKEUP;
+
+ /* anything left to process? */
+ if (kqueue_queue_empty(kq, QOS_INDEX_KQFILE)) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_BEGIN) | DBG_FUNC_END,
+ VM_KERNEL_UNSLIDE_OR_PERM(kq), 1);
+ return -1;
+ }
+
+ /* convert to processing mode */
+ kq->kq_state |= KQ_PROCESSING;
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_BEGIN) | DBG_FUNC_END,
+ VM_KERNEL_UNSLIDE_OR_PERM(kq));
+
+ return 0;
+}
+
+/*
+ * Try to end the processing, only called when a workq thread is attempting to
+ * park (KEVENT_FLAG_PARKING is set).
+ *
+ * When returning -1, the kqworkq is setup again so that it is ready to be
+ * processed.
+ */
+static int
+kqworkq_end_processing(struct kqworkq *kqwq, struct kqrequest *kqr,
+ int kevent_flags)
+{
+ if (!kqueue_queue_empty(&kqwq->kqwq_kqueue, kqr->kqr_qos_index)) {
+ /* remember we didn't process everything */
+ kq_req_lock(kqwq);
+ kqr->kqr_state |= KQR_WAKEUP;
+ kq_req_unlock(kqwq);
+ }
+
+ if (kevent_flags & KEVENT_FLAG_PARKING) {
+ /*
+ * if acknowledge events "succeeds" it means there are events,
+ * which is a failure condition for end_processing.
+ */
+ int rc = kqworkq_acknowledge_events(kqwq, kqr, kevent_flags,
+ KQWQAE_END_PROCESSING);
+ if (rc == 0) {
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Try to end the processing, only called when a workq thread is attempting to
+ * park (KEVENT_FLAG_PARKING is set).
+ *
+ * When returning -1, the kqworkq is setup again so that it is ready to be
+ * processed (as if kqworkloop_begin_processing had just been called).
+ *
+ * If successful and KEVENT_FLAG_PARKING was set in the kevent_flags,
+ * the kqworkloop is unbound from its servicer as a side effect.
+ */
+static int
+kqworkloop_end_processing(struct kqworkloop *kqwl, int flags, int kevent_flags)
+{
+ struct kqueue *kq = &kqwl->kqwl_kqueue;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ thread_qos_t old_override = THREAD_QOS_UNSPECIFIED, qos_override;
+ thread_t thread = kqr->kqr_thread;
+ int rc = 0;
+
+ kqlock_held(kq);
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_END) | DBG_FUNC_START,
+ kqwl->kqwl_dynamicid, 0, 0);
+
+ if (flags & KQ_PROCESSING) {
+ assert(kq->kq_state & KQ_PROCESSING);
+
+ /*
+ * If we still have queued stayactive knotes, remember we didn't finish
+ * processing all of them. This should be extremely rare and would
+ * require to have a lot of them registered and fired.
+ */
+ if (!TAILQ_EMPTY(&kqwl->kqwl_queue[KQWL_BUCKET_STAYACTIVE])) {
+ kq_req_lock(kqwl);
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_WAKEUP_QOS,
+ KQWL_BUCKET_STAYACTIVE);
+ kq_req_unlock(kqwl);
+ }
+
+ /*
+ * When KEVENT_FLAG_PARKING is set, we need to attempt an unbind while
+ * still under the lock.
+ *
+ * So we do everything kqworkloop_unbind() would do, but because we're
+ * inside kqueue_process(), if the workloop actually received events
+ * while our locks were dropped, we have the opportunity to fail the end
+ * processing and loop again.
+ *
+ * This avoids going through the process-wide workqueue lock hence
+ * scales better.
+ */
+ if (kevent_flags & KEVENT_FLAG_PARKING) {
+ qos_override = kqworkloop_acknowledge_events(kqwl);
+ }
+ }
+
+ kq_req_lock(kqwl);
+
+ if (kevent_flags & KEVENT_FLAG_PARKING) {
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_PARKING, qos_override);
+ if ((kqr->kqr_state & KQR_WAKEUP) && !kqwl->kqwl_owner) {
+ /*
+ * Reset wakeup bit to notice stay active events firing while we are
+ * processing, as we cannot rely on the stayactive bucket emptiness.
+ */
+ kqr->kqr_wakeup_indexes &= ~KQWL_STAYACTIVE_FIRED_BIT;
+ rc = -1;
+ } else {
+ old_override = kqworkloop_unbind_locked(kqwl, thread);
+ (void)kqueue_release(kqwl, KQUEUE_CANT_BE_LAST_REF);
+ kq->kq_state &= ~flags;
+ }
+ } else {
+ kq->kq_state &= ~flags;
+ kqr->kqr_state |= KQR_R2K_NOTIF_ARMED;
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_RECOMPUTE_WAKEUP_QOS, 0);
+ }
+
+ kq_req_unlock(kqwl);
+
+ if (old_override) {
+ thread_drop_ipc_override(thread);
+ }
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_END) | DBG_FUNC_END,
+ kqwl->kqwl_dynamicid, 0, 0);
+
+ return rc;
+}
+
+/*
+ * Called with kqueue lock held.
+ */
+static void
+kqfile_end_processing(struct kqueue *kq)
+{
+ struct knote *kn;
+ struct kqtailq *suppressq;
+ int procwait;
+
+ kqlock_held(kq);
+
+ assert((kq->kq_state & (KQ_WORKQ|KQ_WORKLOOP)) == 0);
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_END),
+ VM_KERNEL_UNSLIDE_OR_PERM(kq), 0);
+
+ /*
+ * Return suppressed knotes to their original state.
+ */
+ suppressq = kqueue_get_suppressed_queue(kq, NULL);
+ while ((kn = TAILQ_FIRST(suppressq)) != NULL) {
+ assert(kn->kn_status & KN_SUPPRESSED);
+ knote_unsuppress(kn);
+ }
+
+ procwait = (kq->kq_state & KQ_PROCWAIT);
+ kq->kq_state &= ~(KQ_PROCESSING | KQ_PROCWAIT);
+
+ if (procwait) {
+ /* first wake up any thread already waiting to process */
+ waitq_wakeup64_all((struct waitq *)&kq->kq_wqs,
+ CAST_EVENT64_T(suppressq),
+ THREAD_AWAKENED,
+ WAITQ_ALL_PRIORITIES);
+ }
+}
+
+static int
+kqueue_workloop_ctl_internal(proc_t p, uintptr_t cmd, uint64_t __unused options,
+ struct kqueue_workloop_params *params, int *retval)
+{
+ int error = 0;
+ int fd;
+ struct fileproc *fp;
+ struct kqueue *kq;
+ struct kqworkloop *kqwl;
+ struct filedesc *fdp = p->p_fd;
+ workq_threadreq_param_t trp = { };
+
+ switch (cmd) {
+ case KQ_WORKLOOP_CREATE:
+ if (!params->kqwlp_flags) {
+ error = EINVAL;
+ break;
+ }
+
+ if ((params->kqwlp_flags & KQ_WORKLOOP_CREATE_SCHED_PRI) &&
+ (params->kqwlp_sched_pri < 1 ||
+ params->kqwlp_sched_pri > 63 /* MAXPRI_USER */)) {
+ error = EINVAL;
+ break;
+ }
+
+ if ((params->kqwlp_flags & KQ_WORKLOOP_CREATE_SCHED_POL) &&
+ invalid_policy(params->kqwlp_sched_pol)) {
+ error = EINVAL;
+ break;
+ }
+
+ if ((params->kqwlp_flags & KQ_WORKLOOP_CREATE_CPU_PERCENT) &&
+ (params->kqwlp_cpu_percent <= 0 ||
+ params->kqwlp_cpu_percent > 100 ||
+ params->kqwlp_cpu_refillms <= 0 ||
+ params->kqwlp_cpu_refillms > 0x00ffffff)) {
+ error = EINVAL;
+ break;
+ }
+
+ if (params->kqwlp_flags & KQ_WORKLOOP_CREATE_SCHED_PRI) {
+ trp.trp_flags |= TRP_PRIORITY;
+ trp.trp_pri = params->kqwlp_sched_pri;
+ }
+ if (params->kqwlp_flags & KQ_WORKLOOP_CREATE_SCHED_POL) {
+ trp.trp_flags |= TRP_POLICY;
+ trp.trp_pol = params->kqwlp_sched_pol;
+ }
+ if (params->kqwlp_flags & KQ_WORKLOOP_CREATE_CPU_PERCENT) {
+ trp.trp_flags |= TRP_CPUPERCENT;
+ trp.trp_cpupercent = (uint8_t)params->kqwlp_cpu_percent;
+ trp.trp_refillms = params->kqwlp_cpu_refillms;
+ }
+
+ error = kevent_get_kq(p, params->kqwlp_id, &trp,
+ KEVENT_FLAG_DYNAMIC_KQUEUE | KEVENT_FLAG_WORKLOOP |
+ KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST , &fp, &fd, &kq);
+ if (error) {
+ break;
+ }
+
+ if (!(fdp->fd_flags & FD_WORKLOOP)) {
+ /* FD_WORKLOOP indicates we've ever created a workloop
+ * via this syscall but its only ever added to a process, never
+ * removed.
+ */
+ proc_fdlock(p);
+ fdp->fd_flags |= FD_WORKLOOP;
+ proc_fdunlock(p);
+ }
+ break;
+ case KQ_WORKLOOP_DESTROY:
+ error = kevent_get_kq(p, params->kqwlp_id, NULL,
+ KEVENT_FLAG_DYNAMIC_KQUEUE | KEVENT_FLAG_WORKLOOP |
+ KEVENT_FLAG_DYNAMIC_KQ_MUST_EXIST , &fp, &fd, &kq);
+ if (error) {
+ break;
+ }
+ kqlock(kq);
+ kqwl = (struct kqworkloop *)kq;
+ trp.trp_value = kqwl->kqwl_params;
+ if (trp.trp_flags && !(trp.trp_flags & TRP_RELEASED)) {
+ trp.trp_flags |= TRP_RELEASED;
+ kqueue_release(kq, KQUEUE_CANT_BE_LAST_REF);
+ } else {
+ error = EINVAL;
+ }
+ kqunlock(kq);
+ kqueue_release_last(p, kq);
+ break;
+ }
+ *retval = 0;
+ return error;
+}
+
+int
+kqueue_workloop_ctl(proc_t p, struct kqueue_workloop_ctl_args *uap, int *retval)
+{
+ struct kqueue_workloop_params params = {
+ .kqwlp_id = 0,
+ };
+ if (uap->sz < sizeof(params.kqwlp_version)) {
+ return EINVAL;
+ }
+
+ size_t copyin_sz = MIN(sizeof(params), uap->sz);
+ int rv = copyin(uap->addr, ¶ms, copyin_sz);
+ if (rv) {
+ return rv;
+ }
+
+ if (params.kqwlp_version != (int)uap->sz) {
+ return EINVAL;
+ }
+
+ return kqueue_workloop_ctl_internal(p, uap->cmd, uap->options, ¶ms,
+ retval);
+}
+
+/*
+ * 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).
+ *
+ * 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 *callback_data,
+ struct filt_process_s *process_data,
+ int *countp)
+{
+ struct uthread *ut = get_bsdthread_info(current_thread());
+ struct kqrequest *kqr = ut->uu_kqr_bound;
+ struct knote *kn;
+ unsigned int flags = process_data ? process_data->fp_flags : 0;
+ int nevents = 0, error = 0, rc = 0;
+ struct kqtailq *base_queue, *queue;
+ kqueue_t kqu = { .kq = kq };
+#if DEBUG || DEVELOPMENT
+ int retries = 64;
+#endif
+
+ if (kq->kq_state & KQ_WORKQ) {
+ if (kqr == NULL || (kqr->kqr_state & KQR_WORKLOOP)) {
+ return EJUSTRETURN;
+ }
+ rc = kqworkq_begin_processing(kqu.kqwq, kqr, flags);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ if (ut->uu_kqr_bound != &kqu.kqwl->kqwl_request) {
+ return EJUSTRETURN;
+ }
+ rc = kqworkloop_begin_processing(kqu.kqwl, flags);
+ } else {
+ rc = kqfile_begin_processing(kq);
+ }
+
+ if (rc == -1) {
+ /* Nothing to process */
+ *countp = 0;
+ return 0;
+ }
+
+ /*
+ * loop through the enqueued knotes associated with this request,
+ * processing each one. Each request may have several queues
+ * of knotes to process (depending on the type of kqueue) so we
+ * have to loop through all the queues as long as we have additional
+ * space.
+ */
+
+process_again:
+ if (kq->kq_state & KQ_WORKQ) {
+ base_queue = queue = &kqu.kqwq->kqwq_queue[kqr->kqr_qos_index];
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ base_queue = &kqu.kqwl->kqwl_queue[0];
+ queue = &kqu.kqwl->kqwl_queue[KQWL_NBUCKETS - 1];
+ } else {
+ base_queue = queue = &kq->kq_queue[QOS_INDEX_KQFILE];
+ }
+
+ do {
+ while (error == 0 && (kn = TAILQ_FIRST(queue)) != NULL) {
+ error = knote_process(kn, callback, callback_data, process_data);
+ if (error == EJUSTRETURN) {
+ error = 0;
+ } else {
+ nevents++;
+ }
+ /* error is EWOULDBLOCK when the out event array is full */
+ }
+
+ if (error == EWOULDBLOCK) {
+ /* break out if no more space for additional events */
+ error = 0;
+ break;
+ }
+ } while (queue-- > base_queue);
+
+ *countp = nevents;
+
+ /*
+ * If KEVENT_FLAG_PARKING is set, and no kevents have been returned,
+ * we want to unbind the kqrequest from the thread.
+ *
+ * However, because the kq locks are dropped several times during process,
+ * new knotes may have fired again, in which case, we want to fail the end
+ * processing and process again, until it converges.
+ *
+ * If we returned events however, end processing never fails.
+ */
+ if (error || nevents) flags &= ~KEVENT_FLAG_PARKING;
+ if (kq->kq_state & KQ_WORKQ) {
+ rc = kqworkq_end_processing(kqu.kqwq, kqr, flags);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ rc = kqworkloop_end_processing(kqu.kqwl, KQ_PROCESSING, flags);
+ } else {
+ kqfile_end_processing(kq);
+ rc = 0;
+ }
+ if (rc == -1) {
+ assert(flags & KEVENT_FLAG_PARKING);
+#if DEBUG || DEVELOPMENT
+ if (retries-- == 0) {
+ panic("kevent: way too many knote_process retries, kq: %p (0x%02x)",
+ kq, kq->kq_state);
+ }
+#endif
+ goto process_again;
+ }
+ 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_save.uus_kqueue_scan;
+ struct kqueue *kq = (struct kqueue *)data;
+ struct filt_process_s *process_data = cont_args->process_data;
+ int error;
+ int count;
+
+ /* convert the (previous) wait_result to a proper error */
+ switch (wait_result) {
+ case THREAD_AWAKENED: {
+ kqlock(kq);
+ retry:
+ error = kqueue_process(kq, cont_args->call, cont_args->data,
+ process_data, &count);
+ if (error == 0 && count == 0) {
+ if (kq->kq_state & KQ_DRAIN) {
+ kqunlock(kq);
+ goto drain;
+ }
+
+ if (kq->kq_state & KQ_WAKEUP)
+ goto retry;
+
+ waitq_assert_wait64((struct waitq *)&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;
+ case THREAD_RESTART:
+ drain:
+ error = EBADF;
+ 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 *callback_data,
+ struct filt_process_s *process_data,
+ struct timeval *atvp,
+ __unused struct proc *p)
+{
+ thread_continue_t cont = THREAD_CONTINUE_NULL;
+ unsigned int flags;
+ uint64_t deadline;
+ int error;
+ int first;
+ int fd;
+
+ assert(callback != NULL);
+
+ /*
+ * Determine which QoS index we are servicing
+ */
+ flags = (process_data) ? process_data->fp_flags : 0;
+ fd = (process_data) ? process_data->fp_fd : -1;
+
+ 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, callback_data,
+ process_data, &count);
+ 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_save.uus_kqueue_scan;
+
+ cont_args->call = callback;
+ cont_args->cont = continuation;
+ cont_args->deadline = deadline;
+ cont_args->data = callback_data;
+ cont_args->process_data = process_data;
+ cont = kqueue_scan_continue;
+ }
+ }
+
+ if (kq->kq_state & KQ_DRAIN) {
+ kqunlock(kq);
+ return EBADF;
+ }
+
+ /* If awakened during processing, try again */
+ if (kq->kq_state & KQ_WAKEUP) {
+ kqunlock(kq);
+ continue;
+ }
+
+ /* go ahead and wait */
+ waitq_assert_wait64_leeway((struct waitq *)&kq->kq_wqs,
+ KQ_EVENT, THREAD_ABORTSAFE,
+ TIMEOUT_URGENCY_USER_NORMAL,
+ deadline, TIMEOUT_NO_LEEWAY);
+ 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;
+ case THREAD_RESTART:
+ return EBADF;
+ 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 *wq_link_id,
+ __unused vfs_context_t ctx)
+{
+ struct kqueue *kq = (struct kqueue *)fp->f_data;
+ struct kqtailq *queue;
+ struct kqtailq *suppressq;
+ struct knote *kn;
+ int retnum = 0;
+
+ if (which != FREAD)
+ return (0);
+
+ kqlock(kq);
+
+ assert((kq->kq_state & KQ_WORKQ) == 0);
+
+ /*
+ * 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 (wq_link_id != NULL) {
+ thread_t cur_act = current_thread();
+ struct uthread * ut = get_bsdthread_info(cur_act);
+
+ kq->kq_state |= KQ_SEL;
+ waitq_link((struct waitq *)&kq->kq_wqs, ut->uu_wqset,
+ WAITQ_SHOULD_LOCK, (uint64_t *)wq_link_id);
+
+ /* always consume the reserved link object */
+ waitq_link_release(*(uint64_t *)wq_link_id);
+ *(uint64_t *)wq_link_id = 0;
+
+ /*
+ * selprocess() is expecting that we send it back the waitq
+ * that was just added to the thread's waitq set. In order
+ * to not change the selrecord() API (which is exported to
+ * kexts), we pass this value back through the
+ * void *wq_link_id pointer we were passed. We need to use
+ * memcpy here because the pointer may not be properly aligned
+ * on 32-bit systems.
+ */
+ void *wqptr = &kq->kq_wqs;
+ memcpy(wq_link_id, (void *)&wqptr, sizeof(void *));
+ }
+
+ if (kqfile_begin_processing(kq) == -1) {
+ kqunlock(kq);
+ return (0);
+ }
+
+ queue = &kq->kq_queue[QOS_INDEX_KQFILE];
+ if (!TAILQ_EMPTY(queue)) {
+ /*
+ * there is something queued - but it might be a
+ * KN_STAYACTIVE knote, which may or may not have
+ * any events pending. Otherwise, we have to walk
+ * the list of knotes to see, and peek at the
+ * (non-vanished) stay-active ones to be really sure.
+ */
+ while ((kn = (struct knote *)TAILQ_FIRST(queue)) != NULL) {
+ if (kn->kn_status & KN_ACTIVE) {
+ retnum = 1;
+ goto out;
+ }
+ assert(kn->kn_status & KN_STAYACTIVE);
+ knote_suppress(kn);
+ }
+
+ /*
+ * There were no regular events on the queue, so take
+ * a deeper look at the stay-queued ones we suppressed.
+ */
+ suppressq = kqueue_get_suppressed_queue(kq, NULL);
+ while ((kn = (struct knote *)TAILQ_FIRST(suppressq)) != NULL) {
+ KNOTE_LOCK_CTX(knlc);
+ int result = 0;
+
+ /* If didn't vanish while suppressed - peek at it */
+ if ((kn->kn_status & KN_DROPPING) || !knote_lock(kq, kn, &knlc,
+ KNOTE_KQ_LOCK_ON_FAILURE)) {
+ continue;
+ }
+
+ result = filter_call(knote_fops(kn), f_peek(kn));
+
+ kqlock(kq);
+ knote_unlock(kq, kn, &knlc, KNOTE_KQ_LOCK_ALWAYS);
+
+ /* unsuppress it */
+ knote_unsuppress(kn);
+
+ /* has data or it has to report a vanish */
+ if (result & FILTER_ACTIVE) {
+ retnum = 1;
+ goto out;
+ }
+ }
+ }
+
+out:
+ kqfile_end_processing(kq);
+ kqunlock(kq);
+ return (retnum);
+}
+
+/*
+ * kqueue_close -
+ */
+/*ARGSUSED*/
+static int
+kqueue_close(struct fileglob *fg, __unused vfs_context_t ctx)
+{
+ struct kqfile *kqf = (struct kqfile *)fg->fg_data;
+
+ assert((kqf->kqf_state & KQ_WORKQ) == 0);
+ kqueue_dealloc(&kqf->kqf_kqueue);
+ fg->fg_data = NULL;
+ return (0);
+}
+
+/*
+ * Max depth of the nested kq path that can be created.
+ * Note that this has to be less than the size of kq_level
+ * to avoid wrapping around and mislabeling the level.
+ */
+#define MAX_NESTED_KQ 1000
+
+/*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 struct kevent_internal_s *kev, __unused vfs_context_t ctx)
+{
+ struct kqfile *kqf = (struct kqfile *)kn->kn_fp->f_data;
+ struct kqueue *kq = &kqf->kqf_kqueue;
+ struct kqueue *parentkq = knote_get_kq(kn);
+ uint16_t plevel = 0;
+
+ assert((kqf->kqf_state & KQ_WORKQ) == 0);
+
+ if (parentkq == kq || kn->kn_filter != EVFILT_READ) {
+ knote_set_error(kn, EINVAL);
+ return 0;
+ }
+
+ /*
+ * 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.
+ *
+ * Only up to MAX_NESTED_KQ can be nested.
+ */
+
+ kqlock(parentkq);
+ if (parentkq->kq_level > 0 &&
+ parentkq->kq_level < kq->kq_level)
+ {
+ kqunlock(parentkq);
+ knote_set_error(kn, EINVAL);
+ return 0;
+ } else {
+ /* set parent level appropriately */
+ plevel = (parentkq->kq_level == 0)? 2: parentkq->kq_level;
+ if (plevel < kq->kq_level + 1) {
+ if (kq->kq_level + 1 > MAX_NESTED_KQ) {
+ kqunlock(parentkq);
+ knote_set_error(kn, EINVAL);
+ return 0;
+ }
+ plevel = kq->kq_level + 1;
+ }
+
+ parentkq->kq_level = plevel;
+ kqunlock(parentkq);
+
+ kn->kn_filtid = EVFILTID_KQREAD;
+ kqlock(kq);
+ KNOTE_ATTACH(&kqf->kqf_sel.si_note, kn);
+ /* indicate nesting in child, if needed */
+ if (kq->kq_level == 0)
+ kq->kq_level = 1;
+
+ int count = kq->kq_count;
+ kqunlock(kq);
+ return (count > 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;
+
+ assert((kq->kq_state & KQ_WORKQ) == 0);
+
+ kqlock(kq);
+ kq->kq_state |= KQ_DRAIN;
+ kqueue_interrupt(kq);
+ kqunlock(kq);
+ return (0);
+}
+
+/*ARGSUSED*/
+int
+kqueue_stat(struct kqueue *kq, void *ub, int isstat64, proc_t p)
+{
+ assert((kq->kq_state & KQ_WORKQ) == 0);
+
+ kqlock(kq);
+ if (isstat64 != 0) {
+ struct stat64 *sb64 = (struct stat64 *)ub;
+
+ bzero((void *)sb64, sizeof(*sb64));
+ sb64->st_size = kq->kq_count;
+ if (kq->kq_state & KQ_KEV_QOS)
+ sb64->st_blksize = sizeof(struct kevent_qos_s);
+ else if (kq->kq_state & KQ_KEV64)
+ sb64->st_blksize = sizeof(struct kevent64_s);
+ else if (IS_64BIT_PROCESS(p))
+ sb64->st_blksize = sizeof(struct user64_kevent);
+ else
+ sb64->st_blksize = sizeof(struct user32_kevent);
+ sb64->st_mode = S_IFIFO;
+ } else {
+ struct stat *sb = (struct stat *)ub;
+
+ bzero((void *)sb, sizeof(*sb));
+ sb->st_size = kq->kq_count;
+ if (kq->kq_state & KQ_KEV_QOS)
+ sb->st_blksize = sizeof(struct kevent_qos_s);
+ else if (kq->kq_state & KQ_KEV64)
+ sb->st_blksize = sizeof(struct kevent64_s);
+ else if (IS_64BIT_PROCESS(p))
+ sb->st_blksize = sizeof(struct user64_kevent);
+ else
+ sb->st_blksize = sizeof(struct user32_kevent);
+ sb->st_mode = S_IFIFO;
+ }
+ kqunlock(kq);
+ return (0);
+}
+
+/*
+ * Interact with the pthread kext to request a servicing there at a specific QoS
+ * level.
+ *
+ * - Caller holds the workq request lock
+ *
+ * - May be called with the kqueue's wait queue set locked,
+ * so cannot do anything that could recurse on that.
+ */
+static void
+kqueue_threadreq_initiate(struct kqueue *kq, struct kqrequest *kqr,
+ kq_index_t qos, int flags)
+{
+ assert(kqr->kqr_state & KQR_WAKEUP);
+ assert(kqr->kqr_thread == THREAD_NULL);
+ assert((kqr->kqr_state & KQR_THREQUESTED) == 0);
+ struct turnstile *ts = TURNSTILE_NULL;
+
+ if (workq_is_exiting(kq->kq_p)) {
+ return;
+ }
+
+ /* Add a thread request reference on the kqueue. */
+ kqueue_retain(kq);
+
+ kq_req_held(kq);
+
+ if (kq->kq_state & KQ_WORKLOOP) {
+ __assert_only struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+
+ assert(kqwl->kqwl_owner == THREAD_NULL);
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_THREQUEST),
+ kqwl->kqwl_dynamicid, 0, qos, kqr->kqr_state);
+ ts = kqwl->kqwl_turnstile;
+ } else {
+ assert(kq->kq_state & KQ_WORKQ);
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_THREQUEST),
+ -1, 0, qos, kqr->kqr_state);
+ }
+
+ kqr->kqr_state |= KQR_THREQUESTED;
+
+ /*
+ * New-style thread request supported.
+ * Provide the pthread kext a pointer to a workq_threadreq_s structure for
+ * its use until a corresponding kqueue_threadreq_bind callback.
+ */
+#if 0 // 45129862
+ if ((kq->kq_state & KQ_WORKLOOP) && current_proc() == kq->kq_p) {
+ flags |= WORKQ_THREADREQ_SET_AST_ON_FAILURE;
+ }
+#endif
+ if (qos == KQWQ_QOS_MANAGER) {
+ qos = WORKQ_THREAD_QOS_MANAGER;
+ }
+ if (!workq_kern_threadreq_initiate(kq->kq_p, kqr, ts, qos, flags)) {
+ /*
+ * Process is shutting down or exec'ing.
+ * All the kqueues are going to be cleaned up
+ * soon. Forget we even asked for a thread -
+ * and make sure we don't ask for more.
+ */
+ kqr->kqr_state &= ~(KQR_THREQUESTED | KQR_R2K_NOTIF_ARMED);
+ kqueue_release(kq, KQUEUE_CANT_BE_LAST_REF);
+ }
+}
+
+/*
+ * kqueue_threadreq_bind_prepost - prepost the bind to kevent
+ *
+ * This is used when kqueue_threadreq_bind may cause a lock inversion.
+ */
+void
+kqueue_threadreq_bind_prepost(struct proc *p __unused, workq_threadreq_t req,
+ thread_t thread)
+{
+ struct kqrequest *kqr = __container_of(req, struct kqrequest, kqr_req);
+ struct uthread *ut = get_bsdthread_info(thread);
+
+ req->tr_binding_thread = thread;
+ ut->uu_kqr_bound = kqr;
+ req->tr_state = TR_STATE_BINDING;
+
+ struct kqworkloop *kqwl = kqr_kqworkloop(kqr);
+ if (kqwl && kqwl->kqwl_turnstile) {
+ struct turnstile *ts = kqwl->kqwl_turnstile;
+ /*
+ * While a thread request is in flight, the workqueue
+ * is the interlock for the turnstile and can update the inheritor.
+ */
+ turnstile_update_inheritor(ts, thread, TURNSTILE_IMMEDIATE_UPDATE |
+ TURNSTILE_INHERITOR_THREAD);
+ turnstile_update_inheritor_complete(ts, TURNSTILE_INTERLOCK_HELD);
+ }
+}
+
+/*
+ * kqueue_threadreq_bind_commit - commit a bind prepost
+ *
+ * The workq code has to commit any binding prepost before the thread has
+ * a chance to come back to userspace (and do kevent syscalls) or be aborted.
+ */
+void
+kqueue_threadreq_bind_commit(struct proc *p, thread_t thread)
+{
+ struct uthread *ut = get_bsdthread_info(thread);
+ struct kqrequest *kqr = ut->uu_kqr_bound;
+ kqueue_t kqu = kqr_kqueue(p, kqr);
+
+ kq_req_lock(kqu);
+ if (kqr->kqr_req.tr_state == TR_STATE_BINDING) {
+ kqueue_threadreq_bind(p, &kqr->kqr_req, thread, 0);
+ }
+ kq_req_unlock(kqu);
+}
+
+static void
+kqueue_threadreq_modify(struct kqueue *kq, struct kqrequest *kqr, kq_index_t qos)
+{
+ assert(kqr->kqr_state & KQR_THREQUESTED);
+ assert(kqr->kqr_thread == THREAD_NULL);
+
+ kq_req_held(kq);
+
+ int flags = 0;
+#if 0 // 45129862
+ if ((kq->kq_state & KQ_WORKLOOP) && kq->kq_p == current_proc()) {
+ flags |= WORKQ_THREADREQ_SET_AST_ON_FAILURE;
+ }
+#endif
+ workq_kern_threadreq_modify(kq->kq_p, kqr, qos, flags);
+}
+
+/*
+ * kqueue_threadreq_bind - bind thread to processing kqrequest
+ *
+ * The provided thread will be responsible for delivering events
+ * associated with the given kqrequest. Bind it and get ready for
+ * the thread to eventually arrive.
+ */
+void
+kqueue_threadreq_bind(struct proc *p, workq_threadreq_t req, thread_t thread,
+ unsigned int flags)
+{
+ struct kqrequest *kqr = __container_of(req, struct kqrequest, kqr_req);
+ kqueue_t kqu = kqr_kqueue(p, kqr);
+ struct uthread *ut = get_bsdthread_info(thread);
+
+ kq_req_held(kqu);
+
+ assert(kqr->kqr_state & KQR_THREQUESTED);
+ assert(kqr->kqr_thread == THREAD_NULL);
+ assert(ut->uu_kqueue_override == 0);
+
+ if (kqr->kqr_req.tr_state == TR_STATE_BINDING) {
+ assert(ut->uu_kqr_bound == kqr);
+ assert(kqr->kqr_req.tr_binding_thread == thread);
+ kqr->kqr_req.tr_state = TR_STATE_IDLE;
+ kqr->kqr_req.tr_binding_thread = NULL;
+ } else {
+ assert(ut->uu_kqr_bound == NULL);
+ }
+
+ ut->uu_kqr_bound = kqr;
+ kqr->kqr_thread = thread;
+
+ if (kqu.kq->kq_state & KQ_WORKLOOP) {
+ struct turnstile *ts = kqu.kqwl->kqwl_turnstile;
+
+ if (__improbable(thread == kqu.kqwl->kqwl_owner)) {
+ /*
+ * <rdar://problem/38626999> shows that asserting here is not ok.
+ *
+ * This is not supposed to happen for correct use of the interface,
+ * but it is sadly possible for userspace (with the help of memory
+ * corruption, such as over-release of a dispatch queue) to make
+ * the creator thread the "owner" of a workloop.
+ *
+ * Once that happens, and that creator thread picks up the same
+ * workloop as a servicer, we trip this codepath. We need to fixup
+ * the state to forget about this thread being the owner, as the
+ * entire workloop state machine expects servicers to never be
+ * owners and everything would basically go downhill from here.
+ */
+ kqu.kqwl->kqwl_owner = THREAD_NULL;
+ if (kqworkloop_owner_override(kqu.kqwl)) {
+ thread_drop_ipc_override(thread);
+ }
+ thread_ends_owning_workloop(thread);
+ }
+
+ if (ts && (flags & KQUEUE_THREADERQ_BIND_NO_INHERITOR_UPDATE) == 0) {
+ /*
+ * Past this point, the interlock is the kq req lock again,
+ * so we can fix the inheritor for good.
+ */
+ filt_wlupdate_inheritor(kqu.kqwl, ts, TURNSTILE_IMMEDIATE_UPDATE);
+ turnstile_update_inheritor_complete(ts, TURNSTILE_INTERLOCK_HELD);
+ }
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_BIND), kqu.kqwl->kqwl_dynamicid,
+ thread_tid(thread), kqr->kqr_qos_index,
+ (kqr->kqr_override_index << 16) | kqr->kqr_state);
+
+ ut->uu_kqueue_override = kqr->kqr_override_index;
+ if (kqr->kqr_override_index) {
+ thread_add_ipc_override(thread, kqr->kqr_override_index);
+ }
+ } else {
+ assert(kqr->kqr_override_index == 0);
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_BIND), -1,
+ thread_tid(thread), kqr->kqr_qos_index,
+ (kqr->kqr_override_index << 16) | kqr->kqr_state);
+ }
+}
+
+/*
+ * kqueue_threadreq_cancel - abort a pending thread request
+ *
+ * Called when exiting/exec'ing. Forget our pending request.
+ */
+void
+kqueue_threadreq_cancel(struct proc *p, workq_threadreq_t req)
+{
+ struct kqrequest *kqr = __container_of(req, struct kqrequest, kqr_req);
+ kqueue_t kqu = kqr_kqueue(p, kqr);
+
+ kq_req_lock(kqu);
+
+ assert(kqr->kqr_thread == THREAD_NULL);
+ assert(kqr->kqr_state & KQR_THREQUESTED);
+ kqr->kqr_state &= ~(KQR_THREQUESTED | KQR_R2K_NOTIF_ARMED);
+
+ kq_req_unlock(kqu);
+
+ kqueue_release_last(p, kqu); /* may dealloc kqu */
+}
+
+workq_threadreq_param_t
+kqueue_threadreq_workloop_param(workq_threadreq_t req)
+{
+ struct kqrequest *kqr = __container_of(req, struct kqrequest, kqr_req);
+ struct kqworkloop *kqwl;
+ workq_threadreq_param_t trp;
+
+ assert(kqr->kqr_state & KQR_WORKLOOP);
+ kqwl = __container_of(kqr, struct kqworkloop, kqwl_request);
+ trp.trp_value = kqwl->kqwl_params;
+ return trp;
+}
+
+/*
+ * kqueue_threadreq_unbind - unbind thread from processing kqueue
+ *
+ * End processing the per-QoS bucket of events and allow other threads
+ * to be requested for future servicing.
+ *
+ * caller holds a reference on the kqueue.
+ */
+void
+kqueue_threadreq_unbind(struct proc *p, struct kqrequest *kqr)
+{
+ if (kqr->kqr_state & KQR_WORKLOOP) {
+ kqworkloop_unbind(p, kqr_kqworkloop(kqr));
+ } else {
+ kqworkq_unbind(p, kqr);
+ }
+}
+
+/*
+ * If we aren't already busy processing events [for this QoS],
+ * request workq thread support as appropriate.
+ *
+ * TBD - for now, we don't segregate out processing by QoS.
+ *
+ * - May be called with the kqueue's wait queue set locked,
+ * so cannot do anything that could recurse on that.
+ */
+static void
+kqworkq_request_help(struct kqworkq *kqwq, kq_index_t qos_index)
+{
+ struct kqrequest *kqr;
+
+ /* convert to thread qos value */
+ assert(qos_index < KQWQ_NBUCKETS);
+
+ kq_req_lock(kqwq);
+ kqr = kqworkq_get_request(kqwq, qos_index);
+
+ if ((kqr->kqr_state & KQR_WAKEUP) == 0) {
+ kqr->kqr_state |= KQR_WAKEUP;
+ if ((kqr->kqr_state & KQR_THREQUESTED) == 0) {
+ kqueue_threadreq_initiate(&kqwq->kqwq_kqueue, kqr, qos_index, 0);
+ }
+ }
+ kq_req_unlock(kqwq);
+}
+
+static kq_index_t
+kqworkloop_owner_override(struct kqworkloop *kqwl)
+{
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ return MAX(kqr->kqr_qos_index, kqr->kqr_override_index);
+}
+
+static inline void
+kqworkloop_request_fire_r2k_notification(struct kqworkloop *kqwl)
+{
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ kq_req_held(kqwl);
+
+ if (kqr->kqr_state & KQR_R2K_NOTIF_ARMED) {
+ assert(kqr->kqr_thread);
+ kqr->kqr_state &= ~KQR_R2K_NOTIF_ARMED;
+ act_set_astkevent(kqr->kqr_thread, AST_KEVENT_RETURN_TO_KERNEL);
+ }
+}
+
+static void
+kqworkloop_update_threads_qos(struct kqworkloop *kqwl, int op, kq_index_t qos)
+{
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ struct kqueue *kq = &kqwl->kqwl_kqueue;
+ kq_index_t old_owner_override = kqworkloop_owner_override(kqwl);
+ kq_index_t i;
+
+ /* must hold the kqr lock */
+ kq_req_held(kqwl);
+
+ switch (op) {
+ case KQWL_UTQ_UPDATE_WAKEUP_QOS:
+ if (qos == KQWL_BUCKET_STAYACTIVE) {
+ /*
+ * the KQWL_BUCKET_STAYACTIVE is not a QoS bucket, we only remember
+ * a high watermark (kqr_stayactive_qos) of any stay active knote
+ * that was ever registered with this workloop.
+ *
+ * When waitq_set__CALLING_PREPOST_HOOK__() wakes up any stay active
+ * knote, we use this high-watermark as a wakeup-index, and also set
+ * the magic KQWL_BUCKET_STAYACTIVE bit to make sure we remember
+ * there is at least one stay active knote fired until the next full
+ * processing of this bucket.
+ */
+ kqr->kqr_wakeup_indexes |= KQWL_STAYACTIVE_FIRED_BIT;
+ qos = kqr->kqr_stayactive_qos;
+ assert(qos);
+ }
+ if (kqr->kqr_wakeup_indexes & (1 << qos)) {
+ assert(kqr->kqr_state & KQR_WAKEUP);
+ break;
+ }
+
+ kqr->kqr_wakeup_indexes |= (1 << qos);
+ kqr->kqr_state |= KQR_WAKEUP;
+ kqworkloop_request_fire_r2k_notification(kqwl);
+ goto recompute;
+
+ case KQWL_UTQ_UPDATE_STAYACTIVE_QOS:
+ assert(qos);
+ if (kqr->kqr_stayactive_qos < qos) {
+ kqr->kqr_stayactive_qos = qos;
+ if (kqr->kqr_wakeup_indexes & KQWL_STAYACTIVE_FIRED_BIT) {
+ assert(kqr->kqr_state & KQR_WAKEUP);
+ kqr->kqr_wakeup_indexes |= (1 << qos);
+ goto recompute;
+ }
+ }
+ break;
+
+ case KQWL_UTQ_PARKING:
+ case KQWL_UTQ_UNBINDING:
+ kqr->kqr_override_index = qos;
+ /* FALLTHROUGH */
+ case KQWL_UTQ_RECOMPUTE_WAKEUP_QOS:
+ if (op == KQWL_UTQ_RECOMPUTE_WAKEUP_QOS) {
+ assert(qos == THREAD_QOS_UNSPECIFIED);
+ }
+ kqlock_held(kqwl); // to look at kq_queues
+ i = KQWL_BUCKET_STAYACTIVE;
+ if (TAILQ_EMPTY(&kqr->kqr_suppressed)) {
+ kqr->kqr_override_index = THREAD_QOS_UNSPECIFIED;
+ }
+ if (!TAILQ_EMPTY(&kqwl->kqwl_queue[i]) &&
+ (kqr->kqr_wakeup_indexes & KQWL_STAYACTIVE_FIRED_BIT)) {
+ /*
+ * If the KQWL_STAYACTIVE_FIRED_BIT is set, it means a stay active
+ * knote may have fired, so we need to merge in kqr_stayactive_qos.
+ *
+ * Unlike other buckets, this one is never empty but could be idle.
+ */
+ kqr->kqr_wakeup_indexes &= KQWL_STAYACTIVE_FIRED_BIT;
+ kqr->kqr_wakeup_indexes |= (1 << kqr->kqr_stayactive_qos);
+ } else {
+ kqr->kqr_wakeup_indexes = 0;
+ }
+ for (i = THREAD_QOS_UNSPECIFIED + 1; i < KQWL_BUCKET_STAYACTIVE; i++) {
+ if (!TAILQ_EMPTY(&kqwl->kqwl_queue[i])) {
+ kqr->kqr_wakeup_indexes |= (1 << i);
+ }
+ }
+ if (kqr->kqr_wakeup_indexes) {
+ kqr->kqr_state |= KQR_WAKEUP;
+ kqworkloop_request_fire_r2k_notification(kqwl);
+ } else {
+ kqr->kqr_state &= ~KQR_WAKEUP;
+ }
+ goto recompute;
+
+ case KQWL_UTQ_RESET_WAKEUP_OVERRIDE:
+ kqr->kqr_override_index = qos;
+ goto recompute;
+
+ case KQWL_UTQ_UPDATE_WAKEUP_OVERRIDE:
+ recompute:
+ /*
+ * When modifying the wakeup QoS or the override QoS, we always need to
+ * maintain our invariant that kqr_override_index is at least as large
+ * as the highest QoS for which an event is fired.
+ *
+ * However this override index can be larger when there is an overriden
+ * suppressed knote pushing on the kqueue.
+ */
+ if (kqr->kqr_wakeup_indexes > (1 << qos)) {
+ qos = fls(kqr->kqr_wakeup_indexes) - 1; /* fls is 1-based */
+ }
+ if (kqr->kqr_override_index < qos) {
+ kqr->kqr_override_index = qos;
+ }
+ break;
+
+ case KQWL_UTQ_REDRIVE_EVENTS:
+ break;
+
+ case KQWL_UTQ_SET_QOS_INDEX:
+ kqr->kqr_qos_index = qos;
+ break;
+
+ default:
+ panic("unknown kqwl thread qos update operation: %d", op);
+ }
+
+ thread_t kqwl_owner = kqwl->kqwl_owner;
+ thread_t servicer = kqr->kqr_thread;
+ boolean_t qos_changed = FALSE;
+ kq_index_t new_owner_override = kqworkloop_owner_override(kqwl);
+
+ /*
+ * Apply the diffs to the owner if applicable
+ */
+ if (kqwl_owner) {
+#if 0
+ /* JMM - need new trace hooks for owner overrides */
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_THADJUST),
+ kqwl->kqwl_dynamicid, thread_tid(kqwl_owner), kqr->kqr_qos_index,
+ (kqr->kqr_override_index << 16) | kqr->kqr_state);
+#endif
+ if (new_owner_override == old_owner_override) {
+ // nothing to do
+ } else if (old_owner_override == THREAD_QOS_UNSPECIFIED) {
+ thread_add_ipc_override(kqwl_owner, new_owner_override);
+ } else if (new_owner_override == THREAD_QOS_UNSPECIFIED) {
+ thread_drop_ipc_override(kqwl_owner);
+ } else /* old_owner_override != new_owner_override */ {
+ thread_update_ipc_override(kqwl_owner, new_owner_override);
+ }
+ }
+
+ /*
+ * apply the diffs to the servicer
+ */
+ if ((kqr->kqr_state & KQR_THREQUESTED) == 0) {
+ /*
+ * No servicer, nor thread-request
+ *
+ * Make a new thread request, unless there is an owner (or the workloop
+ * is suspended in userland) or if there is no asynchronous work in the
+ * first place.
+ */
+
+ if (kqwl_owner == NULL && (kqr->kqr_state & KQR_WAKEUP)) {
+ int initiate_flags = 0;
+ if (op == KQWL_UTQ_UNBINDING) {
+ initiate_flags = WORKQ_THREADREQ_ATTEMPT_REBIND;
+ }
+ kqueue_threadreq_initiate(kq, kqr, new_owner_override,
+ initiate_flags);
+ }
+ } else if (servicer) {
+ /*
+ * Servicer in flight
+ *
+ * Just apply the diff to the servicer
+ */
+ struct uthread *ut = get_bsdthread_info(servicer);
+ if (ut->uu_kqueue_override != kqr->kqr_override_index) {
+ if (ut->uu_kqueue_override == THREAD_QOS_UNSPECIFIED) {
+ thread_add_ipc_override(servicer, kqr->kqr_override_index);
+ } else if (kqr->kqr_override_index == THREAD_QOS_UNSPECIFIED) {
+ thread_drop_ipc_override(servicer);
+ } else /* ut->uu_kqueue_override != kqr->kqr_override_index */ {
+ thread_update_ipc_override(servicer, kqr->kqr_override_index);
+ }
+ ut->uu_kqueue_override = kqr->kqr_override_index;
+ qos_changed = TRUE;
+ }
+ } else if (new_owner_override == THREAD_QOS_UNSPECIFIED) {
+ /*
+ * No events to deliver anymore.
+ *
+ * However canceling with turnstiles is challenging, so the fact that
+ * the request isn't useful will be discovered by the servicer himself
+ * later on.
+ */
+ } else if (old_owner_override != new_owner_override) {
+ /*
+ * Request is in flight
+ *
+ * Apply the diff to the thread request
+ */
+ kqueue_threadreq_modify(kq, kqr, new_owner_override);
+ qos_changed = TRUE;
+ }
+
+ if (qos_changed) {
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_THADJUST), kqwl->kqwl_dynamicid,
+ thread_tid(kqr->kqr_thread), kqr->kqr_qos_index,
+ (kqr->kqr_override_index << 16) | kqr->kqr_state);
+ }
+}
+
+static void
+kqworkloop_request_help(struct kqworkloop *kqwl, kq_index_t qos_index)
+{
+ /* convert to thread qos value */
+ assert(qos_index < KQWL_NBUCKETS);
+
+ kq_req_lock(kqwl);
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_WAKEUP_QOS, qos_index);
+ kq_req_unlock(kqwl);
+}
+
+static struct kqtailq *
+kqueue_get_queue(struct kqueue *kq, kq_index_t qos_index)
+{
+ if (kq->kq_state & KQ_WORKQ) {
+ assert(qos_index < KQWQ_NBUCKETS);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ assert(qos_index < KQWL_NBUCKETS);
+ } else {
+ assert(qos_index == QOS_INDEX_KQFILE);
+ }
+ static_assert(offsetof(struct kqueue, kq_queue) == sizeof(struct kqueue),
+ "struct kqueue::kq_queue must be exactly at the end");
+ return &kq->kq_queue[qos_index];
+}
+
+static int
+kqueue_queue_empty(struct kqueue *kq, kq_index_t qos_index)
+{
+ return TAILQ_EMPTY(kqueue_get_queue(kq, qos_index));
+}
+
+static struct kqtailq *
+kqueue_get_suppressed_queue(kqueue_t kq, struct knote *kn)
+{
+ if (kq.kq->kq_state & KQ_WORKQ) {
+ return &kqworkq_get_request(kq.kqwq, kn->kn_qos_index)->kqr_suppressed;
+ } else if (kq.kq->kq_state & KQ_WORKLOOP) {
+ return &kq.kqwl->kqwl_request.kqr_suppressed;
+ } else {
+ return &kq.kqf->kqf_suppressed;
+ }
+}
+
+static struct turnstile *
+kqueue_get_turnstile(kqueue_t kqu, bool can_alloc)
+{
+ uint8_t kqr_state;
+
+ if ((kqu.kq->kq_state & KQ_WORKLOOP) == 0) {
+ return TURNSTILE_NULL;
+ }
+
+ kqr_state = os_atomic_load(&kqu.kqwl->kqwl_request.kqr_state, relaxed);
+ if (kqr_state & KQR_ALLOCATED_TURNSTILE) {
+ /* force a dependency to pair with the atomic or with release below */
+ return os_atomic_load_with_dependency_on(&kqu.kqwl->kqwl_turnstile,
+ kqr_state);
+ }
+
+ if (!can_alloc) {
+ return TURNSTILE_NULL;
+ }
+
+ struct turnstile *ts = turnstile_alloc(), *free_ts = TURNSTILE_NULL;
+
+ kq_req_lock(kqu);
+ if (filt_wlturnstile_interlock_is_workq(kqu.kqwl)) {
+ workq_kern_threadreq_lock(kqu.kqwl->kqwl_p);
+ }
+
+ if (kqu.kqwl->kqwl_request.kqr_state & KQR_ALLOCATED_TURNSTILE) {
+ free_ts = ts;
+ ts = kqu.kqwl->kqwl_turnstile;
+ } else {
+ ts = turnstile_prepare((uintptr_t)kqu.kqwl, &kqu.kqwl->kqwl_turnstile,
+ ts, TURNSTILE_WORKLOOPS);
+
+ /* release-barrier to pair with the unlocked load of kqwl_turnstile above */
+ os_atomic_or(&kqu.kqwl->kqwl_request.kqr_state,
+ KQR_ALLOCATED_TURNSTILE, release);
+ }
+
+ if (filt_wlturnstile_interlock_is_workq(kqu.kqwl)) {
+ workq_kern_threadreq_unlock(kqu.kqwl->kqwl_p);
+ }
+ kq_req_unlock(kqu.kqwl);
+
+ if (free_ts) {
+ turnstile_deallocate(free_ts);
+ }
+ return ts;
+}
+
+struct turnstile *
+kqueue_turnstile(struct kqueue *kq)
+{
+ return kqueue_get_turnstile(kq, false);
+}
+
+struct turnstile *
+kqueue_alloc_turnstile(struct kqueue *kq)
+{
+ return kqueue_get_turnstile(kq, true);
+}
+
+static struct kqtailq *
+knote_get_queue(struct knote *kn)
+{
+ return kqueue_get_queue(knote_get_kq(kn), kn->kn_qos_index);
+}
+
+static void
+knote_reset_priority(struct knote *kn, pthread_priority_t pp)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ kq_index_t qos = _pthread_priority_thread_qos(pp);
+
+ assert((kn->kn_status & KN_QUEUED) == 0);
+
+ if (kq->kq_state & KQ_WORKQ) {
+ if (qos == THREAD_QOS_UNSPECIFIED) {
+ /* On workqueues, outside of QoS means MANAGER */
+ qos = KQWQ_QOS_MANAGER;
+ pp = _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
+ } else {
+ pp = _pthread_priority_normalize(pp);
+ }
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ assert((pp & _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG) == 0);
+ pp = _pthread_priority_normalize(pp);
+ } else {
+ pp = _pthread_unspecified_priority();
+ qos = THREAD_QOS_UNSPECIFIED;
+ }
+
+ kn->kn_qos = pp;
+ kn->kn_req_index = qos;
+
+ if ((kn->kn_status & KN_MERGE_QOS) == 0 || qos > kn->kn_qos_override) {
+ /* Never lower QoS when in "Merge" mode */
+ kn->kn_qos_override = qos;
+ }
+
+ /* only adjust in-use qos index when not suppressed */
+ if ((kn->kn_status & KN_SUPPRESSED) == 0) {
+ kn->kn_qos_index = qos;
+ } else if (kq->kq_state & KQ_WORKQ) {
+ kqworkq_update_override((struct kqworkq *)kq, kn, qos);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ kqworkloop_update_override((struct kqworkloop *)kq, qos);
+ }
+}
+
+static void
+knote_set_qos_overcommit(struct knote *kn)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+
+ /* turn overcommit on for the appropriate thread request? */
+ if ((kn->kn_qos & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG) &&
+ (kq->kq_state & KQ_WORKLOOP)) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+
+ /*
+ * This test is racy, but since we never remove this bit,
+ * it allows us to avoid taking a lock.
+ */
+ if (kqr->kqr_state & KQR_THOVERCOMMIT) {
+ return;
+ }
+
+ kq_req_lock(kqwl);
+ kqr->kqr_state |= KQR_THOVERCOMMIT;
+ if (!kqr->kqr_thread && (kqr->kqr_state & KQR_THREQUESTED)) {
+ kqueue_threadreq_modify(kq, kqr, kqr->kqr_req.tr_qos);
+ }
+ kq_req_unlock(kqwl);
+ }
+}
+
+static kq_index_t
+knote_get_qos_override_index(struct knote *kn)
+{
+ return kn->kn_qos_override;
+}
+
+static void
+kqworkq_update_override(struct kqworkq *kqwq, struct knote *kn,
+ kq_index_t override_index)
+{
+ struct kqrequest *kqr;
+ kq_index_t old_override_index;
+ kq_index_t queue_index = kn->kn_qos_index;
+
+ if (override_index <= queue_index) {
+ return;
+ }
+
+ kqr = kqworkq_get_request(kqwq, queue_index);
+
+ kq_req_lock(kqwq);
+ old_override_index = kqr->kqr_override_index;
+ if (override_index > MAX(kqr->kqr_qos_index, old_override_index)) {
+ kqr->kqr_override_index = override_index;
+
+ /* apply the override to [incoming?] servicing thread */
+ if (kqr->kqr_thread) {
+ if (old_override_index)
+ thread_update_ipc_override(kqr->kqr_thread, override_index);
+ else
+ thread_add_ipc_override(kqr->kqr_thread, override_index);
+ }
+ }
+ kq_req_unlock(kqwq);
+}
+
+static void
+kqworkloop_update_override(struct kqworkloop *kqwl, kq_index_t override_index)
+{
+ kq_req_lock(kqwl);
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_WAKEUP_OVERRIDE,
+ override_index);
+ kq_req_unlock(kqwl);
+}
+
+static thread_qos_t
+kqworkloop_unbind_locked(struct kqworkloop *kqwl, thread_t thread)
+{
+ struct uthread *ut = get_bsdthread_info(thread);
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ kq_index_t ipc_override = ut->uu_kqueue_override;
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_UNBIND), kqwl->kqwl_dynamicid,
+ thread_tid(thread), 0, 0);
+
+ kq_req_held(kqwl);
+ assert(ut->uu_kqr_bound == kqr);
+ ut->uu_kqr_bound = NULL;
+ ut->uu_kqueue_override = THREAD_QOS_UNSPECIFIED;
+
+ if (kqwl->kqwl_owner == NULL && kqwl->kqwl_turnstile) {
+ turnstile_update_inheritor(kqwl->kqwl_turnstile,
+ TURNSTILE_INHERITOR_NULL, TURNSTILE_IMMEDIATE_UPDATE);
+ turnstile_update_inheritor_complete(kqwl->kqwl_turnstile,
+ TURNSTILE_INTERLOCK_HELD);
+ }
+
+ kqr->kqr_thread = NULL;
+ kqr->kqr_state &= ~(KQR_THREQUESTED | KQR_R2K_NOTIF_ARMED);
+ return ipc_override;
+}
+
+/*
+ * kqworkloop_unbind - Unbind the servicer thread of a workloop kqueue
+ *
+ * It will acknowledge events, and possibly request a new thread if:
+ * - there were active events left
+ * - we pended waitq hook callouts during processing
+ * - we pended wakeups while processing (or unsuppressing)
+ *
+ * Called with kqueue lock held.
+ */
+static void
+kqworkloop_unbind(proc_t p, struct kqworkloop *kqwl)
+{
+ struct kqueue *kq = &kqwl->kqwl_kqueue;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ thread_t thread = kqr->kqr_thread;
+ int op = KQWL_UTQ_PARKING;
+ kq_index_t ipc_override, qos_override = THREAD_QOS_UNSPECIFIED;
+
+ assert(thread == current_thread());
+
+ kqlock(kqwl);
+
+ /*
+ * Forcing the KQ_PROCESSING flag allows for QoS updates because of
+ * unsuppressing knotes not to be applied until the eventual call to
+ * kqworkloop_update_threads_qos() below.
+ */
+ assert((kq->kq_state & KQ_PROCESSING) == 0);
+ if (!TAILQ_EMPTY(&kqr->kqr_suppressed)) {
+ kq->kq_state |= KQ_PROCESSING;
+ qos_override = kqworkloop_acknowledge_events(kqwl);
+ kq->kq_state &= ~KQ_PROCESSING;
+ }
+
+ kq_req_lock(kqwl);
+
+ ipc_override = kqworkloop_unbind_locked(kqwl, thread);
+ kqworkloop_update_threads_qos(kqwl, op, qos_override);
+
+ kq_req_unlock(kqwl);
+
+ kqunlock(kqwl);
+
+ /*
+ * Drop the override on the current thread last, after the call to
+ * kqworkloop_update_threads_qos above.
+ */
+ if (ipc_override) {
+ thread_drop_ipc_override(thread);
+ }
+
+ /* If last reference, dealloc the workloop kq */
+ kqueue_release_last(p, kqwl);
+}
+
+static thread_qos_t
+kqworkq_unbind_locked(__assert_only struct kqworkq *kqwq,
+ struct kqrequest *kqr, thread_t thread)
+{
+ struct uthread *ut = get_bsdthread_info(thread);
+ kq_index_t old_override = kqr->kqr_override_index;
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_UNBIND), -1,
+ thread_tid(kqr->kqr_thread), kqr->kqr_qos_index, 0);
+
+ kq_req_held(kqwq);
+ assert(ut->uu_kqr_bound == kqr);
+ ut->uu_kqr_bound = NULL;
+ kqr->kqr_thread = NULL;
+ kqr->kqr_state &= ~(KQR_THREQUESTED | KQR_R2K_NOTIF_ARMED);
+ kqr->kqr_override_index = THREAD_QOS_UNSPECIFIED;
+
+ return old_override;
+}
+
+/*
+ * kqworkq_unbind - unbind of a workq kqueue from a thread
+ *
+ * We may have to request new threads.
+ * This can happen there are no waiting processing threads and:
+ * - there were active events we never got to (count > 0)
+ * - we pended waitq hook callouts during processing
+ * - we pended wakeups while processing (or unsuppressing)
+ */
+static void
+kqworkq_unbind(proc_t p, struct kqrequest *kqr)
+{
+ struct kqworkq *kqwq = (struct kqworkq *)p->p_fd->fd_wqkqueue;
+ __assert_only int rc;
+
+ kqlock(kqwq);
+ rc = kqworkq_acknowledge_events(kqwq, kqr, 0, KQWQAE_UNBIND);
+ assert(rc == -1);
+ kqunlock(kqwq);
+}
+
+struct kqrequest *
+kqworkq_get_request(struct kqworkq *kqwq, kq_index_t qos_index)
+{
+ assert(qos_index < KQWQ_NBUCKETS);
+ return &kqwq->kqwq_request[qos_index];
+}
+
+static void
+knote_apply_qos_override(struct knote *kn, kq_index_t qos_index)
+{
+ assert((kn->kn_status & KN_QUEUED) == 0);
+
+ kn->kn_qos_override = qos_index;
+
+ if (kn->kn_status & KN_SUPPRESSED) {
+ struct kqueue *kq = knote_get_kq(kn);
+ /*
+ * For suppressed events, the kn_qos_index field cannot be touched as it
+ * allows us to know on which supress queue the knote is for a kqworkq.
+ *
+ * Also, there's no natural push applied on the kqueues when this field
+ * changes anyway. We hence need to apply manual overrides in this case,
+ * which will be cleared when the events are later acknowledged.
+ */
+ if (kq->kq_state & KQ_WORKQ) {
+ kqworkq_update_override((struct kqworkq *)kq, kn, qos_index);
+ } else {
+ kqworkloop_update_override((struct kqworkloop *)kq, qos_index);
+ }
+ } else {
+ kn->kn_qos_index = qos_index;
+ }
+}
+
+static bool
+knote_should_apply_qos_override(struct kqueue *kq, struct knote *kn, int result,
+ thread_qos_t *qos_out)
+{
+ thread_qos_t qos_index = (result >> FILTER_ADJUST_EVENT_QOS_SHIFT) & 7;
+
+ kqlock_held(kq);
+
+ assert(result & FILTER_ADJUST_EVENT_QOS_BIT);
+ assert(qos_index < THREAD_QOS_LAST);
+
+ /*
+ * Early exit for knotes that should not change QoS
+ *
+ * It is safe to test kn_req_index against MANAGER / STAYACTIVE because
+ * knotes with such kn_req_index values never change for their entire
+ * lifetime.
+ */
+ if (__improbable(!knote_fops(kn)->f_adjusts_qos)) {
+ panic("filter %d cannot change QoS", kn->kn_filtid);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ if (kn->kn_req_index == KQWL_BUCKET_STAYACTIVE) {
+ return false;
+ }
+ } else if (kq->kq_state & KQ_WORKQ) {
+ if (kn->kn_req_index == KQWQ_QOS_MANAGER) {
+ return false;
+ }
+ } else {
+ return false;
+ }
+
+ /*
+ * knotes with the FALLBACK flag will only use their registration QoS if the
+ * incoming event has no QoS, else, the registration QoS acts as a floor.
+ */
+ if (kn->kn_qos & _PTHREAD_PRIORITY_FALLBACK_FLAG) {
+ if (qos_index == THREAD_QOS_UNSPECIFIED)
+ qos_index = kn->kn_req_index;
+ } else {
+ if (qos_index < kn->kn_req_index)
+ qos_index = kn->kn_req_index;
+ }
+ if ((kn->kn_status & KN_MERGE_QOS) && (qos_index < kn->kn_qos_override)) {
+ /* Never lower QoS when in "Merge" mode */
+ return false;
+ }
+
+ if ((kn->kn_status & KN_LOCKED) && kn->kn_inuse) {
+ /*
+ * When we're trying to update the QoS override and that both an
+ * f_event() and other f_* calls are running concurrently, any of these
+ * in flight calls may want to perform overrides that aren't properly
+ * serialized with each other.
+ *
+ * The first update that observes this racy situation enters a "Merge"
+ * mode which causes subsequent override requests to saturate the
+ * override instead of replacing its value.
+ *
+ * This mode is left when knote_unlock() or knote_call_filter_event()
+ * observe that no other f_* routine is in flight.
+ */
+ kn->kn_status |= KN_MERGE_QOS;
+ }
+
+ if (kn->kn_qos_override == qos_index) {
+ return false;
+ }
+
+ *qos_out = qos_index;
+ return true;
+}
+
+static void
+knote_adjust_qos(struct kqueue *kq, struct knote *kn, int result)
+{
+ thread_qos_t qos;
+ if (knote_should_apply_qos_override(kq, kn, result, &qos)) {
+ knote_dequeue(kn);
+ knote_apply_qos_override(kn, qos);
+ if (knote_enqueue(kn) && (kn->kn_status & KN_ACTIVE)) {
+ knote_wakeup(kn);
+ }
+ }
+}
+
+static void
+knote_wakeup(struct knote *kn)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+
+ kqlock_held(kq);
+
+ if (kq->kq_state & KQ_WORKQ) {
+ struct kqworkq *kqwq = (struct kqworkq *)kq;
+
+ kqworkq_request_help(kqwq, kn->kn_qos_index);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+
+ /*
+ * kqworkloop_end_processing() will perform the required QoS
+ * computations when it unsets the processing mode.
+ */
+ if (!kqworkloop_is_processing_on_current_thread(kqwl)) {
+ kqworkloop_request_help(kqwl, kn->kn_qos_index);
+ }
+ } else {
+ struct kqfile *kqf = (struct kqfile *)kq;
+
+ /* flag wakeups during processing */
+ if (kq->kq_state & KQ_PROCESSING)
+ kq->kq_state |= KQ_WAKEUP;
+
+ /* wakeup a thread waiting on this queue */
+ if (kq->kq_state & (KQ_SLEEP | KQ_SEL)) {
+ kq->kq_state &= ~(KQ_SLEEP | KQ_SEL);
+ waitq_wakeup64_all((struct waitq *)&kq->kq_wqs, KQ_EVENT,
+ THREAD_AWAKENED, WAITQ_ALL_PRIORITIES);
+ }
+
+ /* wakeup other kqueues/select sets we're inside */
+ KNOTE(&kqf->kqf_sel.si_note, 0);
+ }
+}
+
+/*
+ * Called with the kqueue locked
+ */
+static void
+kqueue_interrupt(struct kqueue *kq)
+{
+ assert((kq->kq_state & KQ_WORKQ) == 0);
+
+ /* wakeup sleeping threads */
+ if ((kq->kq_state & (KQ_SLEEP | KQ_SEL)) != 0) {
+ kq->kq_state &= ~(KQ_SLEEP | KQ_SEL);
+ (void)waitq_wakeup64_all((struct waitq *)&kq->kq_wqs,
+ KQ_EVENT,
+ THREAD_RESTART,
+ WAITQ_ALL_PRIORITIES);
+ }
+
+ /* wakeup threads waiting their turn to process */
+ if (kq->kq_state & KQ_PROCWAIT) {
+ struct kqtailq *suppressq;
+
+ assert(kq->kq_state & KQ_PROCESSING);
+
+ kq->kq_state &= ~KQ_PROCWAIT;
+ suppressq = kqueue_get_suppressed_queue(kq, NULL);
+ (void)waitq_wakeup64_all((struct waitq *)&kq->kq_wqs,
+ CAST_EVENT64_T(suppressq),
+ THREAD_RESTART,
+ WAITQ_ALL_PRIORITIES);
+ }
+}
+
+/*
+ * Called back from waitq code when no threads waiting and the hook was set.
+ *
+ * Interrupts are likely disabled and spin locks are held - minimal work
+ * can be done in this context!!!
+ *
+ * JMM - in the future, this will try to determine which knotes match the
+ * wait queue wakeup and apply these wakeups against those knotes themselves.
+ * For now, all the events dispatched this way are dispatch-manager handled,
+ * so hard-code that for now.
+ */
+void
+waitq_set__CALLING_PREPOST_HOOK__(void *kq_hook, void *knote_hook, int qos)
+{
+#pragma unused(knote_hook, qos)
+
+ struct kqueue *kq = (struct kqueue *)kq_hook;
+
+ if (kq->kq_state & KQ_WORKQ) {
+ struct kqworkq *kqwq = (struct kqworkq *)kq;
+
+ kqworkq_request_help(kqwq, KQWQ_QOS_MANAGER);
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+
+ kqworkloop_request_help(kqwl, KQWL_BUCKET_STAYACTIVE);
+ }
+}
+
+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.
+ */
+void
+knote(struct klist *list, long hint)
+{
+ struct knote *kn;
+
+ SLIST_FOREACH(kn, list, kn_selnext) {
+ struct kqueue *kq = knote_get_kq(kn);
+ kqlock(kq);
+ knote_call_filter_event(kq, kn, hint);
+ 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));
+}
+
+/*
+ * knote_vanish - Indicate that the source has vanished
+ *
+ * If the knote has requested EV_VANISHED delivery,
+ * arrange for that. Otherwise, deliver a NOTE_REVOKE
+ * event for backward compatibility.
+ *
+ * The knote is marked as having vanished, but is not
+ * actually detached from the source in this instance.
+ * The actual detach is deferred until the knote drop.
+ *
+ * Our caller already has the object lock held. Calling
+ * the detach routine would try to take that lock
+ * recursively - which likely is not supported.
+ */
+void
+knote_vanish(struct klist *list)
+{
+ struct knote *kn;
+ struct knote *kn_next;
+
+ SLIST_FOREACH_SAFE(kn, list, kn_selnext, kn_next) {
+ struct kqueue *kq = knote_get_kq(kn);
+
+ kqlock(kq);
+ if (kn->kn_status & KN_REQVANISH) {
+ /* If EV_VANISH supported - prepare to deliver one */
+ kn->kn_status |= KN_VANISHED;
+ knote_activate(kn);
+ } else {
+ knote_call_filter_event(kq, kn, NOTE_REVOKE);
+ }
+ kqunlock(kq);
+ }
+}
+
+/*
+ * Force a lazy allocation of the waitqset link
+ * of the kq_wqs associated with the kn
+ * if it wasn't already allocated.
+ *
+ * This allows knote_link_waitq to never block
+ * if reserved_link is not NULL.
+ */
+void
+knote_link_waitqset_lazy_alloc(struct knote *kn)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ waitq_set_lazy_init_link(&kq->kq_wqs);
+}
+
+/*
+ * Check if a lazy allocation for the waitqset link
+ * of the kq_wqs is needed.
+ */
+boolean_t
+knote_link_waitqset_should_lazy_alloc(struct knote *kn)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ return waitq_set_should_lazy_init_link(&kq->kq_wqs);
+}
+
+/*
+ * 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.
+ * waitq locked by caller.
+ *
+ * caller provides the wait queue link structure and insures that the kq->kq_wqs
+ * is linked by previously calling knote_link_waitqset_lazy_alloc.
+ */
+int
+knote_link_waitq(struct knote *kn, struct waitq *wq, uint64_t *reserved_link)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ kern_return_t kr;
+
+ kr = waitq_link(wq, &kq->kq_wqs, WAITQ_ALREADY_LOCKED, reserved_link);
+ if (kr == KERN_SUCCESS) {
+ knote_markstayactive(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_waitq(struct knote *kn, struct waitq *wq)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ kern_return_t kr;
+
+ kr = waitq_unlink(wq, &kq->kq_wqs);
+ knote_clearstayactive(kn);
+ return ((kr != KERN_SUCCESS) ? EINVAL : 0);
+}
+
+/*
+ * remove all knotes referencing a specified fd
+ *
+ * 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 klist *list;
+ struct knote *kn;
+ KNOTE_LOCK_CTX(knlc);
+
+restart:
+ list = &p->p_fd->fd_knlist[fd];
+ SLIST_FOREACH(kn, list, kn_link) {
+ struct kqueue *kq = knote_get_kq(kn);
+
+ kqlock(kq);
+
+ if (kq->kq_p != p)
+ panic("%s: proc mismatch (kq->kq_p=%p != p=%p)",
+ __func__, kq->kq_p, p);
+
+ /*
+ * If the knote supports EV_VANISHED delivery,
+ * transition it to vanished mode (or skip over
+ * it if already vanished).
+ */
+ if (kn->kn_status & KN_VANISHED) {
+ kqunlock(kq);
+ continue;
+ }
+
+ proc_fdunlock(p);
+ if (!knote_lock(kq, kn, &knlc, KNOTE_KQ_LOCK_ON_SUCCESS)) {
+ /* the knote was dropped by someone, nothing to do */
+ } else if (kn->kn_status & KN_REQVANISH) {
+ kn->kn_status |= KN_VANISHED;
+ kn->kn_status &= ~KN_ATTACHED;
+
+ kqunlock(kq);
+ knote_fops(kn)->f_detach(kn);
+ if (knote_fops(kn)->f_isfd)
+ fp_drop(p, kn->kn_id, kn->kn_fp, 0);
+ kqlock(kq);
+
+ knote_activate(kn);
+ knote_unlock(kq, kn, &knlc, KNOTE_KQ_UNLOCK);
+ } else {
+ knote_drop(kq, kn, &knlc);
+ }
+
+ proc_fdlock(p);
+ goto restart;
+ }
+}
+
+/*
+ * knote_fdfind - lookup a knote in the fd table for process
+ *
+ * If the filter is file-based, lookup based on fd index.
+ * Otherwise use a hash based on the ident.
+ *
+ * Matching is based on kq, filter, and ident. Optionally,
+ * it may also be based on the udata field in the kevent -
+ * allowing multiple event registration for the file object
+ * per kqueue.
+ *
+ * fd_knhashlock or fdlock held on entry (and exit)
+ */
+static struct knote *
+knote_fdfind(struct kqueue *kq,
+ struct kevent_internal_s *kev,
+ bool is_fd,
+ struct proc *p)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct klist *list = NULL;
+ struct knote *kn = NULL;
+
+ /*
+ * determine where to look for the knote
+ */
+ if (is_fd) {
+ /* fd-based knotes are linked off the fd table */
+ if (kev->ident < (u_int)fdp->fd_knlistsize) {
+ list = &fdp->fd_knlist[kev->ident];
+ }
+ } else if (fdp->fd_knhashmask != 0) {
+ /* hash non-fd knotes here too */
+ list = &fdp->fd_knhash[KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
+ }
+
+ /*
+ * scan the selected list looking for a match
+ */
+ if (list != NULL) {
+ SLIST_FOREACH(kn, list, kn_link) {
+ if (kq == knote_get_kq(kn) &&
+ kev->ident == kn->kn_id &&
+ kev->filter == kn->kn_filter) {
+ if (kev->flags & EV_UDATA_SPECIFIC) {
+ if ((kn->kn_status & KN_UDATA_SPECIFIC) &&
+ kev->udata == kn->kn_udata) {
+ break; /* matching udata-specific knote */
+ }
+ } else if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) {
+ break; /* matching non-udata-specific knote */
+ }
+ }
+ }
+ }
+ return kn;
+}
+
+/*
+ * kq_add_knote- Add knote to the fd table for process
+ * while checking for duplicates.
+ *
+ * All file-based filters associate a list of knotes by file
+ * descriptor index. All other filters hash the knote by ident.
+ *
+ * May have to grow the table of knote lists to cover the
+ * file descriptor index presented.
+ *
+ * fd_knhashlock and fdlock unheld on entry (and exit).
+ *
+ * Takes a rwlock boost if inserting the knote is successful.
+ */
+static int
+kq_add_knote(struct kqueue *kq, struct knote *kn, struct knote_lock_ctx *knlc,
+ struct proc *p)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct klist *list = NULL;
+ int ret = 0;
+ bool is_fd = knote_fops(kn)->f_isfd;
+
+ if (is_fd)
+ proc_fdlock(p);
+ else
+ knhash_lock(p);
+
+ if (knote_fdfind(kq, &kn->kn_kevent, is_fd, p) != NULL) {
+ /* found an existing knote: we can't add this one */
+ ret = ERESTART;
+ goto out_locked;
+ }
+
+ /* knote was not found: add it now */
+ if (!is_fd) {
+ if (fdp->fd_knhashmask == 0) {
+ u_long size = 0;
+
+ list = hashinit(CONFIG_KN_HASHSIZE, M_KQUEUE, &size);
+ if (list == NULL) {
+ ret = ENOMEM;
+ goto out_locked;
+ }
+
+ fdp->fd_knhash = list;
+ fdp->fd_knhashmask = size;
+ }
+
+ list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
+ SLIST_INSERT_HEAD(list, kn, kn_link);
+ ret = 0;
+ goto out_locked;
+
+ } else {
+ /* knote is fd based */
+
+ 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) {
+ ret = EINVAL;
+ goto out_locked;
+ }
+ /* have to grow the fd_knlist */
+ size = fdp->fd_knlistsize;
+ while (size <= kn->kn_id)
+ size += KQEXTENT;
+
+ if (size >= (UINT_MAX/sizeof(struct klist *))) {
+ ret = EINVAL;
+ goto out_locked;
+ }
+
+ MALLOC(list, struct klist *,
+ size * sizeof(struct klist *), M_KQUEUE, M_WAITOK);
+ if (list == NULL) {
+ ret = ENOMEM;
+ goto out_locked;
+ }
+
+ 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);
+ ret = 0;
+ goto out_locked;
+
+ }
+
+out_locked:
+ if (ret == 0) {
+ kqlock(kq);
+ assert((kn->kn_status & KN_LOCKED) == 0);
+ (void)knote_lock(kq, kn, knlc, KNOTE_KQ_UNLOCK);
+ }
+ if (is_fd)
+ proc_fdunlock(p);
+ else
+ knhash_unlock(p);
+
+ return ret;
+}
+
+/*
+ * kq_remove_knote - remove a knote from the fd table for process
+ *
+ * If the filter is file-based, remove based on fd index.
+ * Otherwise remove from the hash based on the ident.
+ *
+ * fd_knhashlock and fdlock unheld on entry (and exit).
+ */
+static void
+kq_remove_knote(struct kqueue *kq, struct knote *kn, struct proc *p,
+ struct knote_lock_ctx *knlc)
+{
+ struct filedesc *fdp = p->p_fd;
+ struct klist *list = NULL;
+ uint16_t kq_state;
+ bool is_fd;
+
+ is_fd = knote_fops(kn)->f_isfd;
+
+ if (is_fd)
+ proc_fdlock(p);
+ else
+ knhash_lock(p);
+
+ if (is_fd) {
+ assert ((u_int)fdp->fd_knlistsize > kn->kn_id);
+ 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);
+ kq_state = kq->kq_state;
+ if (knlc) {
+ knote_unlock_cancel(kq, kn, knlc, KNOTE_KQ_UNLOCK);
+ } else {
+ kqunlock(kq);
+ }
+ if (is_fd)
+ proc_fdunlock(p);
+ else
+ knhash_unlock(p);
+
+ if (kq_state & KQ_DYNAMIC)
+ kqueue_release_last(p, kq);
+}
+
+/*
+ * kq_find_knote_and_kq_lock - lookup a knote in the fd table for process
+ * and, if the knote is found, acquires the kqlock while holding the fd table lock/spinlock.
+ *
+ * fd_knhashlock or fdlock unheld on entry (and exit)
+ */
+
+static struct knote *
+kq_find_knote_and_kq_lock(struct kqueue *kq, struct kevent_internal_s *kev,
+ bool is_fd, struct proc *p)
+{
+ struct knote * ret;
+
+ if (is_fd)
+ proc_fdlock(p);
+ else
+ knhash_lock(p);
+
+ ret = knote_fdfind(kq, kev, is_fd, p);
+
+ if (ret) {
+ kqlock(kq);
+ }
+
+ if (is_fd)
+ proc_fdunlock(p);
+ else
+ knhash_unlock(p);
+
+ return ret;
+}
+/*
+ * knote_drop - disconnect and drop the knote
+ *
+ * Called with the kqueue locked, returns with the kqueue unlocked.
+ *
+ * If a knote locking context is passed, it is canceled.
+ *
+ * The knote may have already been detached from
+ * (or not yet attached to) its source object.
+ */
+static void
+knote_drop(struct kqueue *kq, struct knote *kn, struct knote_lock_ctx *knlc)
+{
+ struct proc *p = kq->kq_p;
+
+ kqlock_held(kq);
+
+ assert((kn->kn_status & KN_DROPPING) == 0);
+ if (knlc == NULL) {
+ assert((kn->kn_status & KN_LOCKED) == 0);
+ }
+ kn->kn_status |= KN_DROPPING;
+
+ knote_unsuppress(kn);
+ knote_dequeue(kn);
+ knote_wait_for_filter_events(kq, kn);
+
+ /* If we are attached, disconnect from the source first */
+ if (kn->kn_status & KN_ATTACHED) {
+ knote_fops(kn)->f_detach(kn);
+ }
+
+ /* kq may be freed when kq_remove_knote() returns */
+ kq_remove_knote(kq, kn, p, knlc);
+ if (knote_fops(kn)->f_isfd && ((kn->kn_status & KN_VANISHED) == 0))
+ 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)
+{
+ if (kn->kn_status & KN_ACTIVE)
+ return;
+
+ KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KNOTE_ACTIVATE),
+ kn->kn_udata, kn->kn_status | (kn->kn_id << 32),
+ kn->kn_filtid);
+
+ kn->kn_status |= KN_ACTIVE;
+ if (knote_enqueue(kn))
+ knote_wakeup(kn);
+}
+
+/* called with kqueue lock held */
+static void
+knote_deactivate(struct knote *kn)
+{
+ kn->kn_status &= ~KN_ACTIVE;
+ if ((kn->kn_status & KN_STAYACTIVE) == 0)
+ knote_dequeue(kn);
+}
+
+/* called with kqueue lock held */
+static void
+knote_enable(struct knote *kn)
+{
+ if ((kn->kn_status & KN_DISABLED) == 0)
+ return;
+
+ kn->kn_status &= ~KN_DISABLED;
+
+ if (kn->kn_status & KN_SUPPRESSED) {
+ /*
+ * it is possible for userland to have knotes registered for a given
+ * workloop `wl_orig` but really handled on another workloop `wl_new`.
+ *
+ * In that case, rearming will happen from the servicer thread of
+ * `wl_new` which if `wl_orig` is no longer being serviced, would cause
+ * this knote to stay suppressed forever if we only relied on
+ * kqworkloop_acknowledge_events to be called by `wl_orig`.
+ *
+ * However if we see the KQ_PROCESSING bit on `wl_orig` set, we can't
+ * unsuppress because that would mess with the processing phase of
+ * `wl_orig`, however it also means kqworkloop_acknowledge_events()
+ * will be called.
+ */
+ struct kqueue *kq = knote_get_kq(kn);
+ if ((kq->kq_state & KQ_PROCESSING) == 0) {
+ knote_unsuppress(kn);
+ }
+ } else if (knote_enqueue(kn)) {
+ knote_wakeup(kn);
+ }
+}
+
+/* called with kqueue lock held */
+static void
+knote_disable(struct knote *kn)
+{
+ if (kn->kn_status & KN_DISABLED)
+ return;
+
+ kn->kn_status |= KN_DISABLED;
+ knote_dequeue(kn);
+}
+
+/* called with kqueue lock held */
+static void
+knote_suppress(struct knote *kn)
+{
+ struct kqtailq *suppressq;
+ struct kqueue *kq = knote_get_kq(kn);
+
+ kqlock_held(kq);
+
+ if (kn->kn_status & KN_SUPPRESSED)
+ return;
+
+ knote_dequeue(kn);
+ kn->kn_status |= KN_SUPPRESSED;
+ suppressq = kqueue_get_suppressed_queue(kq, kn);
+ TAILQ_INSERT_TAIL(suppressq, kn, kn_tqe);
+}
+
+/* called with kqueue lock held */
+static void
+knote_unsuppress(struct knote *kn)
+{
+ struct kqtailq *suppressq;
+ struct kqueue *kq = knote_get_kq(kn);
+
+ kqlock_held(kq);
+
+ if ((kn->kn_status & KN_SUPPRESSED) == 0)
+ return;
+
+ kn->kn_status &= ~KN_SUPPRESSED;
+ suppressq = kqueue_get_suppressed_queue(kq, kn);
+ TAILQ_REMOVE(suppressq, kn, kn_tqe);
+
+ /*
+ * If the knote is no longer active, reset its push,
+ * and resynchronize kn_qos_index with kn_qos_override
+ */
+ if ((kn->kn_status & KN_ACTIVE) == 0) {
+ kn->kn_qos_override = kn->kn_req_index;
+ }
+ kn->kn_qos_index = kn->kn_qos_override;
+
+ /* don't wakeup if unsuppressing just a stay-active knote */
+ if (knote_enqueue(kn) && (kn->kn_status & KN_ACTIVE)) {
+ knote_wakeup(kn);
+ }
+
+ if ((kq->kq_state & KQ_WORKLOOP) && TAILQ_EMPTY(suppressq)) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+
+ if (kqworkloop_is_processing_on_current_thread(kqwl)) {
+ /*
+ * kqworkloop_end_processing() or kqworkloop_begin_processing()
+ * will perform the required QoS computations when it unsets the
+ * processing mode.
+ */
+ } else {
+ kq_req_lock(kqwl);
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_RESET_WAKEUP_OVERRIDE, 0);
+ kq_req_unlock(kqwl);
+ }
+ }
+}
+
+/* called with kqueue lock held */
+static int
+knote_enqueue(struct knote *kn)
+{
+ if ((kn->kn_status & (KN_ACTIVE | KN_STAYACTIVE)) == 0 ||
+ (kn->kn_status & (KN_DISABLED | KN_SUPPRESSED | KN_DROPPING)))
+ return 0;
+
+ if ((kn->kn_status & KN_QUEUED) == 0) {
+ struct kqtailq *queue = knote_get_queue(kn);
+ struct kqueue *kq = knote_get_kq(kn);
+
+ kqlock_held(kq);
+ TAILQ_INSERT_TAIL(queue, kn, kn_tqe);
+ kn->kn_status |= KN_QUEUED;
+ kq->kq_count++;
+ return 1;
+ }
+ return ((kn->kn_status & KN_STAYACTIVE) != 0);
+}
+
+
+/* called with kqueue lock held */
+static void
+knote_dequeue(struct knote *kn)
+{
+ struct kqueue *kq = knote_get_kq(kn);
+ struct kqtailq *queue;
+
+ kqlock_held(kq);
+
+ if ((kn->kn_status & KN_QUEUED) == 0)
+ return;
+
+ queue = knote_get_queue(kn);
+ TAILQ_REMOVE(queue, kn, kn_tqe);
+ 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");
+
+ kqfile_zone = zinit(sizeof(struct kqfile), 8192*sizeof(struct kqfile),
+ 8192, "kqueue file zone");
+
+ kqworkq_zone = zinit(sizeof(struct kqworkq), 8192*sizeof(struct kqworkq),
+ 8192, "kqueue workq zone");
+
+ kqworkloop_zone = zinit(sizeof(struct kqworkloop), 8192*sizeof(struct kqworkloop),
+ 8192, "kqueue workloop 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();
+
+#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)
+
+const struct filterops *
+knote_fops(struct knote *kn)
+{
+ return sysfilt_ops[kn->kn_filtid];
+}
+
+static struct knote *
+knote_alloc(void)
+{
+ struct knote *kn = ((struct knote *)zalloc(knote_zone));
+ bzero(kn, sizeof(struct knote));
+ return kn;
+}
+
+static void
+knote_free(struct knote *kn)
+{
+ assert(kn->kn_inuse == 0);
+ assert((kn->kn_status & KN_LOCKED) == 0);
+ zfree(knote_zone, kn);
+}
+
+#if SOCKETS
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/protosw.h>
+#include <sys/domain.h>
+#include <sys/mbuf.h>
+#include <sys/kern_event.h>
+#include <sys/malloc.h>
+#include <sys/sys_domain.h>
+#include <sys/syslog.h>
+
+#ifndef ROUNDUP64
+#define ROUNDUP64(x) P2ROUNDUP((x), sizeof (u_int64_t))
+#endif
+
+#ifndef ADVANCE64
+#define ADVANCE64(p, n) (void*)((char *)(p) + ROUNDUP64(n))
+#endif
+
+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,
+}
+};
+
+__private_extern__ int kevt_getstat SYSCTL_HANDLER_ARGS;
+__private_extern__ int kevt_pcblist SYSCTL_HANDLER_ARGS;
+
+SYSCTL_NODE(_net_systm, OID_AUTO, kevt,
+ CTLFLAG_RW|CTLFLAG_LOCKED, 0, "Kernel event family");
+
+struct kevtstat kevtstat;
+SYSCTL_PROC(_net_systm_kevt, OID_AUTO, stats,
+ CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0,
+ kevt_getstat, "S,kevtstat", "");
+
+SYSCTL_PROC(_net_systm_kevt, OID_AUTO, pcblist,
+ CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0,
+ kevt_pcblist, "S,xkevtpcb", "");
+
+static lck_mtx_t *
+event_getlock(struct socket *so, int flags)
+{
+#pragma unused(flags)
+ 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 = sonullevent;
+ 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);
+ kevtstat.kes_pcbcount--;
+ kevtstat.kes_gencnt++;
+ 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);
+ kevtstat.kes_pcbcount++;
+ kevtstat.kes_gencnt++;
+ 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) {
+ OSIncrementAtomic64((SInt64 *)&kevtstat.kes_badvendor);
+ 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) {
+ OSIncrementAtomic64((SInt64 *)&kevtstat.kes_toobig);
+ return (EMSGSIZE);
+ }
+
+ m = m_get(M_WAIT, MT_DATA);
+ if (m == 0) {
+ OSIncrementAtomic64((SInt64 *)&kevtstat.kes_nomem);
+ return (ENOMEM);
+ }
+ 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;
}
- kn = kn0;
}
}
+
+ m2 = m_copym(m, 0, m->m_len, M_WAIT);
+ if (m2 == 0) {
+ OSIncrementAtomic64((SInt64 *)&kevtstat.kes_nomem);
+ m_free(m);
+ lck_mtx_unlock(&ev_pcb->evp_mtx);
+ lck_rw_done(kev_rwlock);
+ return (ENOMEM);
+ }
+ if (sbappendrecord(&ev_pcb->evp_socket->so_rcv, m2)) {
+ /*
+ * We use "m" for the socket stats as it would be
+ * unsafe to use "m2"
+ */
+ so_inc_recv_data_stat(ev_pcb->evp_socket,
+ 1, m->m_len, MBUF_TC_BE);
+
+ sorwakeup(ev_pcb->evp_socket);
+ OSIncrementAtomic64((SInt64 *)&kevtstat.kes_posted);
+ } else {
+ OSIncrementAtomic64((SInt64 *)&kevtstat.kes_fullsock);
+ }
+ lck_mtx_unlock(&ev_pcb->evp_mtx);
}
- _FREE(kq, M_KQUEUE);
- fp->f_data = NULL;
+ m_free(m);
+ lck_rw_done(kev_rwlock);
return (0);
}
-/*ARGSUSED*/
static int
-kqueue_kqfilter(struct file *fp, struct knote *kn, struct proc *p)
+kev_control(struct socket *so,
+ u_long cmd,
+ caddr_t data,
+ __unused struct ifnet *ifp,
+ __unused struct proc *p)
{
- struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
-
- if (kn->kn_filter != EVFILT_READ || (kq->kq_state & KQ_SEL))
- return (1);
+ 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);
+ }
- kn->kn_fop = &kqread_filtops;
- KNOTE_ATTACH(&kq->kq_sel.si_note, kn);
return (0);
}
-/*ARGSUSED*/
int
-kqueue_stat(struct file *fp, struct stat *st, struct proc *p)
+kevt_getstat SYSCTL_HANDLER_ARGS
{
- struct kqueue *kq = (struct kqueue *)fp->f_data;
+#pragma unused(oidp, arg1, arg2)
+ int error = 0;
- bzero((void *)st, sizeof(*st));
- st->st_size = kq->kq_count;
- st->st_blksize = sizeof(struct kevent);
- st->st_mode = S_IFIFO;
- return (0);
+ lck_rw_lock_shared(kev_rwlock);
+
+ if (req->newptr != USER_ADDR_NULL) {
+ error = EPERM;
+ goto done;
+ }
+ if (req->oldptr == USER_ADDR_NULL) {
+ req->oldidx = sizeof(struct kevtstat);
+ goto done;
+ }
+
+ error = SYSCTL_OUT(req, &kevtstat,
+ MIN(sizeof(struct kevtstat), req->oldlen));
+done:
+ lck_rw_done(kev_rwlock);
+
+ return (error);
}
-static void
-kqueue_wakeup(struct kqueue *kq)
+__private_extern__ int
+kevt_pcblist SYSCTL_HANDLER_ARGS
{
+#pragma unused(oidp, arg1, arg2)
+ int error = 0;
+ int n, i;
+ struct xsystmgen xsg;
+ void *buf = NULL;
+ size_t item_size = ROUNDUP64(sizeof (struct xkevtpcb)) +
+ ROUNDUP64(sizeof (struct xsocket_n)) +
+ 2 * ROUNDUP64(sizeof (struct xsockbuf_n)) +
+ ROUNDUP64(sizeof (struct xsockstat_n));
+ struct kern_event_pcb *ev_pcb;
+
+ buf = _MALLOC(item_size, M_TEMP, M_WAITOK | M_ZERO);
+ if (buf == NULL)
+ return (ENOMEM);
+
+ lck_rw_lock_shared(kev_rwlock);
+
+ n = kevtstat.kes_pcbcount;
- if (kq->kq_state & KQ_SLEEP) {
- kq->kq_state &= ~KQ_SLEEP;
- wakeup(kq);
+ if (req->oldptr == USER_ADDR_NULL) {
+ req->oldidx = (n + n/8) * item_size;
+ goto done;
+ }
+ if (req->newptr != USER_ADDR_NULL) {
+ error = EPERM;
+ goto done;
+ }
+ bzero(&xsg, sizeof (xsg));
+ xsg.xg_len = sizeof (xsg);
+ xsg.xg_count = n;
+ xsg.xg_gen = kevtstat.kes_gencnt;
+ xsg.xg_sogen = so_gencnt;
+ error = SYSCTL_OUT(req, &xsg, sizeof (xsg));
+ if (error) {
+ goto done;
+ }
+ /*
+ * We are done if there is no pcb
+ */
+ if (n == 0) {
+ goto done;
}
- if (kq->kq_state & KQ_SEL) {
- // kq->kq_state &= ~KQ_SEL; /* remove for now */
- selwakeup(&kq->kq_sel);
- } else
- KNOTE(&kq->kq_sel.si_note, 0);
-}
-void
-klist_init(struct klist *list)
-{
- SLIST_INIT(list);
-}
+ i = 0;
+ for (i = 0, ev_pcb = LIST_FIRST(&kern_event_head);
+ i < n && ev_pcb != NULL;
+ i++, ev_pcb = LIST_NEXT(ev_pcb, evp_link)) {
+ struct xkevtpcb *xk = (struct xkevtpcb *)buf;
+ struct xsocket_n *xso = (struct xsocket_n *)
+ ADVANCE64(xk, sizeof (*xk));
+ struct xsockbuf_n *xsbrcv = (struct xsockbuf_n *)
+ ADVANCE64(xso, sizeof (*xso));
+ struct xsockbuf_n *xsbsnd = (struct xsockbuf_n *)
+ ADVANCE64(xsbrcv, sizeof (*xsbrcv));
+ struct xsockstat_n *xsostats = (struct xsockstat_n *)
+ ADVANCE64(xsbsnd, sizeof (*xsbsnd));
+
+ bzero(buf, item_size);
+
+ lck_mtx_lock(&ev_pcb->evp_mtx);
+
+ xk->kep_len = sizeof(struct xkevtpcb);
+ xk->kep_kind = XSO_EVT;
+ xk->kep_evtpcb = (uint64_t)VM_KERNEL_ADDRPERM(ev_pcb);
+ xk->kep_vendor_code_filter = ev_pcb->evp_vendor_code_filter;
+ xk->kep_class_filter = ev_pcb->evp_class_filter;
+ xk->kep_subclass_filter = ev_pcb->evp_subclass_filter;
+
+ sotoxsocket_n(ev_pcb->evp_socket, xso);
+ sbtoxsockbuf_n(ev_pcb->evp_socket ?
+ &ev_pcb->evp_socket->so_rcv : NULL, xsbrcv);
+ sbtoxsockbuf_n(ev_pcb->evp_socket ?
+ &ev_pcb->evp_socket->so_snd : NULL, xsbsnd);
+ sbtoxsockstat_n(ev_pcb->evp_socket, xsostats);
+
+ lck_mtx_unlock(&ev_pcb->evp_mtx);
+
+ error = SYSCTL_OUT(req, buf, item_size);
+ }
-/*
- * walk down a list of knotes, activating them if their event has triggered.
- */
-void
-knote(struct klist *list, long hint)
-{
- struct knote *kn;
+ if (error == 0) {
+ /*
+ * Give the user an updated idea of our state.
+ * If the generation differs from what we told
+ * her before, she knows that something happened
+ * while we were processing this request, and it
+ * might be necessary to retry.
+ */
+ bzero(&xsg, sizeof (xsg));
+ xsg.xg_len = sizeof (xsg);
+ xsg.xg_count = n;
+ xsg.xg_gen = kevtstat.kes_gencnt;
+ xsg.xg_sogen = so_gencnt;
+ error = SYSCTL_OUT(req, &xsg, sizeof (xsg));
+ if (error) {
+ goto done;
+ }
+ }
- SLIST_FOREACH(kn, list, kn_selnext)
- if (kn->kn_fop->f_event(kn, hint))
- KNOTE_ACTIVATE(kn);
-}
+done:
+ lck_rw_done(kev_rwlock);
-/*
- * attach a knote to the specified list. Return true if this is the first entry.
- */
-int
-knote_attach(struct klist *list, struct knote *kn)
-{
- int ret = SLIST_EMPTY(list);
- SLIST_INSERT_HEAD(list, kn, kn_selnext);
- return ret;
+ return (error);
}
-/*
- * detach a knote from the specified list. Return true if that was the last entry.
- */
+#endif /* SOCKETS */
+
+
int
-knote_detach(struct klist *list, struct knote *kn)
+fill_kqueueinfo(struct kqueue *kq, struct kqueue_info * kinfo)
{
- SLIST_REMOVE(list, kn, knote, kn_selnext);
- return SLIST_EMPTY(list);
-}
+ struct vinfo_stat * st;
-/*
- * remove all knotes from a specified klist
- */
-void
-knote_remove(struct proc *p, struct klist *list)
-{
- struct knote *kn;
+ st = &kinfo->kq_stat;
- while ((kn = SLIST_FIRST(list)) != NULL) {
- kn->kn_fop->f_detach(kn);
- knote_drop(kn, p);
- }
-}
+ st->vst_size = kq->kq_count;
+ if (kq->kq_state & KQ_KEV_QOS)
+ st->vst_blksize = sizeof(struct kevent_qos_s);
+ else 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;
+ st->vst_ino = (kq->kq_state & KQ_DYNAMIC) ?
+ ((struct kqworkloop *)kq)->kqwl_dynamicid : 0;
-/*
- * remove all knotes referencing a specified fd
- */
-void
-knote_fdclose(struct proc *p, int fd)
-{
- struct filedesc *fdp = p->p_fd;
- struct klist *list = &fdp->fd_knlist[fd];
+ /* flags exported to libproc as PROC_KQUEUE_* (sys/proc_info.h) */
+#define PROC_KQUEUE_MASK (KQ_SEL|KQ_SLEEP|KQ_KEV32|KQ_KEV64|KQ_KEV_QOS|KQ_WORKQ|KQ_WORKLOOP)
+ kinfo->kq_state = kq->kq_state & PROC_KQUEUE_MASK;
- knote_remove(p, list);
+ return (0);
}
-static void
-knote_fdpattach(struct knote *kn, struct filedesc *fdp)
+static int
+fill_kqueue_dyninfo(struct kqueue *kq, struct kqueue_dyninfo *kqdi)
{
- struct klist *list;
- int size;
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+ struct kqrequest *kqr = &kqwl->kqwl_request;
+ workq_threadreq_param_t trp = {};
+ int err;
- if (! kn->kn_fop->f_isfd) {
- if (fdp->fd_knhashmask == 0)
- fdp->fd_knhash = hashinit(KN_HASHSIZE, M_KQUEUE,
- &fdp->fd_knhashmask);
- list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
- goto done;
+ if ((kq->kq_state & KQ_WORKLOOP) == 0) {
+ return EINVAL;
}
- if (fdp->fd_knlistsize <= kn->kn_id) {
- size = fdp->fd_knlistsize;
- while (size <= kn->kn_id)
- size += KQEXTENT;
- MALLOC(list, struct klist *,
- size * sizeof(struct klist *), M_KQUEUE, M_WAITOK);
- 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 *));
- if (fdp->fd_knlist != NULL)
- FREE(fdp->fd_knlist, M_KQUEUE);
- fdp->fd_knlistsize = size;
- fdp->fd_knlist = list;
+ if ((err = fill_kqueueinfo(kq, &kqdi->kqdi_info))) {
+ return err;
}
- list = &fdp->fd_knlist[kn->kn_id];
-done:
- SLIST_INSERT_HEAD(list, kn, kn_link);
- kn->kn_status = 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, struct proc *p)
-{
- struct filedesc *fdp = p->p_fd;
- struct klist *list;
+ kq_req_lock(kqwl);
- 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)];
+ kqdi->kqdi_servicer = thread_tid(kqr->kqr_thread);
+ kqdi->kqdi_owner = thread_tid(kqwl->kqwl_owner);
+ kqdi->kqdi_request_state = kqr->kqr_state;
+ kqdi->kqdi_async_qos = kqr->kqr_qos_index;
+ kqdi->kqdi_events_qos = kqr->kqr_override_index;
+ kqdi->kqdi_sync_waiters = kqr->kqr_dsync_waiters;
+ kqdi->kqdi_sync_waiter_qos = 0;
- SLIST_REMOVE(list, kn, knote, kn_link);
- if (kn->kn_status & KN_QUEUED)
- knote_dequeue(kn);
- if (kn->kn_fop->f_isfd)
- fdrop(kn->kn_fp, p);
- knote_free(kn);
-}
+ trp.trp_value = kqwl->kqwl_params;
+ if (trp.trp_flags & TRP_PRIORITY)
+ kqdi->kqdi_pri = trp.trp_pri;
+ else
+ kqdi->kqdi_pri = 0;
+ if (trp.trp_flags & TRP_POLICY)
+ kqdi->kqdi_pol = trp.trp_pol;
+ else
+ kqdi->kqdi_pol = 0;
-static void
-knote_enqueue(struct knote *kn)
-{
- struct kqueue *kq = kn->kn_kq;
- int s = splhigh();
+ if (trp.trp_flags & TRP_CPUPERCENT)
+ kqdi->kqdi_cpupercent = trp.trp_cpupercent;
+ else
+ kqdi->kqdi_cpupercent = 0;
- KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
+ kq_req_unlock(kqwl);
- TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
- kn->kn_status |= KN_QUEUED;
- kq->kq_count++;
- splx(s);
- kqueue_wakeup(kq);
+ return 0;
}
-static void
-knote_dequeue(struct knote *kn)
+
+void
+knote_markstayactive(struct knote *kn)
{
- struct kqueue *kq = kn->kn_kq;
- int s = splhigh();
+ struct kqueue *kq = knote_get_kq(kn);
+ kq_index_t qos;
- KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
+ kqlock(kq);
+ kn->kn_status |= KN_STAYACTIVE;
- TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
- kn->kn_status &= ~KN_QUEUED;
- kq->kq_count--;
- splx(s);
+ /*
+ * Making a knote stay active is a property of the knote that must be
+ * established before it is fully attached.
+ */
+ assert(kn->kn_status & KN_ATTACHING);
+ assert((kn->kn_status & (KN_QUEUED | KN_SUPPRESSED)) == 0);
+
+ /* handle all stayactive knotes on the (appropriate) manager */
+ if (kq->kq_state & KQ_WORKQ) {
+ qos = KQWQ_QOS_MANAGER;
+ } else if (kq->kq_state & KQ_WORKLOOP) {
+ struct kqworkloop *kqwl = (struct kqworkloop *)kq;
+
+ qos = _pthread_priority_thread_qos(kn->kn_qos);
+ assert(qos && qos < THREAD_QOS_LAST);
+ kq_req_lock(kq);
+ kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_STAYACTIVE_QOS, qos);
+ kq_req_unlock(kq);
+ qos = KQWL_BUCKET_STAYACTIVE;
+ } else {
+ qos = THREAD_QOS_UNSPECIFIED;
+ }
+
+ kn->kn_req_index = qos;
+ kn->kn_qos_override = qos;
+ kn->kn_qos_index = qos;
+
+ knote_activate(kn);
+ kqunlock(kq);
}
void
-knote_init(void)
+knote_clearstayactive(struct knote *kn)
{
- knote_zone = zinit(sizeof(struct knote), 8192*sizeof(struct knote), 8192, "knote zone");
+ kqlock(knote_get_kq(kn));
+ kn->kn_status &= ~KN_STAYACTIVE;
+ knote_deactivate(kn);
+ kqunlock(knote_get_kq(kn));
}
-SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL)
-static struct knote *
-knote_alloc(void)
+static unsigned long
+kevent_extinfo_emit(struct kqueue *kq, struct knote *kn, struct kevent_extinfo *buf,
+ unsigned long buflen, unsigned long nknotes)
{
- return ((struct knote *)zalloc(knote_zone));
+ for (; kn; kn = SLIST_NEXT(kn, kn_link)) {
+ if (kq == knote_get_kq(kn)) {
+ if (nknotes < buflen) {
+ struct kevent_extinfo *info = &buf[nknotes];
+ struct kevent_internal_s *kevp = &kn->kn_kevent;
+
+ kqlock(kq);
+
+ info->kqext_kev = (struct kevent_qos_s){
+ .ident = kevp->ident,
+ .filter = kevp->filter,
+ .flags = kevp->flags,
+ .fflags = kevp->fflags,
+ .data = (int64_t)kevp->data,
+ .udata = kevp->udata,
+ .ext[0] = kevp->ext[0],
+ .ext[1] = kevp->ext[1],
+ .ext[2] = kevp->ext[2],
+ .ext[3] = kevp->ext[3],
+ .qos = kn->kn_req_index,
+ };
+ info->kqext_sdata = kn->kn_sdata;
+ info->kqext_status = kn->kn_status;
+ info->kqext_sfflags = kn->kn_sfflags;
+
+ kqunlock(kq);
+ }
+
+ /* we return total number of knotes, which may be more than requested */
+ nknotes++;
+ }
+ }
+
+ return nknotes;
}
-static void
-knote_free(struct knote *kn)
+int
+kevent_copyout_proc_dynkqids(void *proc, user_addr_t ubuf, uint32_t ubufsize,
+ int32_t *nkqueues_out)
{
- zfree(knote_zone, (vm_offset_t)kn);
-}
+ proc_t p = (proc_t)proc;
+ struct filedesc *fdp = p->p_fd;
+ unsigned int nkqueues = 0;
+ unsigned long ubuflen = ubufsize / sizeof(kqueue_id_t);
+ size_t buflen, bufsize;
+ kqueue_id_t *kq_ids = NULL;
+ int err = 0;
-#include <sys/param.h>
-#include <sys/socket.h>
-#include <sys/protosw.h>
-#include <sys/domain.h>
-#include <sys/mbuf.h>
-#include <sys/kern_event.h>
-#include <sys/malloc.h>
-#include <sys/sys_domain.h>
-#include <sys/syslog.h>
+ assert(p != NULL);
+ if (ubuf == USER_ADDR_NULL && ubufsize != 0) {
+ err = EINVAL;
+ goto out;
+ }
-int raw_usrreq();
-struct pr_usrreqs event_usrreqs;
+ buflen = min(ubuflen, PROC_PIDDYNKQUEUES_MAX);
-struct protosw eventsw[] = {
- {
- SOCK_RAW, &systemdomain, SYSPROTO_EVENT, PR_ATOMIC,
- 0, 0, 0, 0,
- 0,
- 0, 0, 0, 0,
- 0, &event_usrreqs
- }
-};
+ if (ubuflen != 0) {
+ if (os_mul_overflow(sizeof(kqueue_id_t), buflen, &bufsize)) {
+ err = ERANGE;
+ goto out;
+ }
+ kq_ids = kalloc(bufsize);
+ if (!kq_ids) {
+ err = ENOMEM;
+ goto out;
+ }
+ bzero(kq_ids, bufsize);
+ }
-static
-struct kern_event_head kern_event_head;
+ kqhash_lock(p);
-static u_long static_event_id = 0;
+ if (fdp->fd_kqhashmask > 0) {
+ for (uint32_t i = 0; i < fdp->fd_kqhashmask + 1; i++) {
+ struct kqworkloop *kqwl;
-/*
- * Install the protosw's for the NKE manager. Invoked at
- * extension load time
- */
-int
-kern_event_init(void)
-{
- int retval;
+ SLIST_FOREACH(kqwl, &fdp->fd_kqhash[i], kqwl_hashlink) {
+ /* report the number of kqueues, even if they don't all fit */
+ if (nkqueues < buflen) {
+ kq_ids[nkqueues] = kqwl->kqwl_dynamicid;
+ }
+ nkqueues++;
+ }
+ }
+ }
+
+ kqhash_unlock(p);
+
+ if (kq_ids) {
+ size_t copysize;
+ if (os_mul_overflow(sizeof(kqueue_id_t), min(buflen, nkqueues), ©size)) {
+ err = ERANGE;
+ goto out;
+ }
+
+ assert(ubufsize >= copysize);
+ err = copyout(kq_ids, ubuf, copysize);
+ }
- if ((retval = net_add_proto(eventsw, &systemdomain)) == 0)
- return(KERN_SUCCESS);
-
- log(LOG_WARNING, "Can't install kernel events protocol (%d)\n", retval);
- return(retval);
+out:
+ if (kq_ids) {
+ kfree(kq_ids, bufsize);
+ }
+
+ if (!err) {
+ *nkqueues_out = (int)min(nkqueues, PROC_PIDDYNKQUEUES_MAX);
+ }
+ return err;
}
-int kev_attach(struct socket *so, int proto, struct proc *p)
+int
+kevent_copyout_dynkqinfo(void *proc, kqueue_id_t kq_id, user_addr_t ubuf,
+ uint32_t ubufsize, int32_t *size_out)
{
- int error;
- struct kern_event_pcb *ev_pcb;
-
- error = soreserve(so, KEV_SNDSPACE, KEV_RECVSPACE);
- if (error)
- return error;
+ proc_t p = (proc_t)proc;
+ struct kqueue *kq;
+ int err = 0;
+ struct kqueue_dyninfo kqdi = { };
- ev_pcb = _MALLOC(sizeof(struct kern_event_pcb), M_PCB, M_WAITOK);
- if (ev_pcb == 0)
- return ENOBUFS;
+ assert(p != NULL);
- ev_pcb->ev_socket = so;
- ev_pcb->vendor_code_filter = 0xffffffff;
+ if (ubufsize < sizeof(struct kqueue_info)) {
+ return ENOBUFS;
+ }
- so->so_pcb = (caddr_t) ev_pcb;
- LIST_INSERT_HEAD(&kern_event_head, ev_pcb, ev_link);
+ kqhash_lock(p);
+ kq = kqueue_hash_lookup(p, kq_id);
+ if (!kq) {
+ kqhash_unlock(p);
+ return ESRCH;
+ }
+ kqueue_retain(kq);
+ kqhash_unlock(p);
- return 0;
+ /*
+ * backward compatibility: allow the argument to this call to only be
+ * a struct kqueue_info
+ */
+ if (ubufsize >= sizeof(struct kqueue_dyninfo)) {
+ ubufsize = sizeof(struct kqueue_dyninfo);
+ err = fill_kqueue_dyninfo(kq, &kqdi);
+ } else {
+ ubufsize = sizeof(struct kqueue_info);
+ err = fill_kqueueinfo(kq, &kqdi.kqdi_info);
+ }
+ if (err == 0 && (err = copyout(&kqdi, ubuf, ubufsize)) == 0) {
+ *size_out = ubufsize;
+ }
+ kqueue_release_last(p, kq);
+ return err;
}
-
-int kev_detach(struct socket *so)
+int
+kevent_copyout_dynkqextinfo(void *proc, kqueue_id_t kq_id, user_addr_t ubuf,
+ uint32_t ubufsize, int32_t *nknotes_out)
{
- struct kern_event_pcb *ev_pcb = (struct kern_event_pcb *) so->so_pcb;
+ proc_t p = (proc_t)proc;
+ struct kqueue *kq;
+ int err;
- if (ev_pcb != 0) {
- LIST_REMOVE(ev_pcb, ev_link);
- FREE(ev_pcb, M_PCB);
- so->so_pcb = 0;
- }
+ assert(p != NULL);
- return 0;
-}
+ kqhash_lock(p);
+ kq = kqueue_hash_lookup(p, kq_id);
+ if (!kq) {
+ kqhash_unlock(p);
+ return ESRCH;
+ }
+ kqueue_retain(kq);
+ kqhash_unlock(p);
+ err = pid_kqueue_extinfo(p, kq, ubuf, ubufsize, nknotes_out);
+ kqueue_release_last(p, kq);
+ return err;
+}
-int kev_post_msg(struct kev_msg *event_msg)
+int
+pid_kqueue_extinfo(proc_t p, struct kqueue *kq, user_addr_t ubuf,
+ uint32_t bufsize, int32_t *retval)
{
- struct mbuf *m, *m2;
- struct kern_event_pcb *ev_pcb;
- struct kern_event_msg *ev;
- char *tmp;
- int total_size;
- int i;
+ struct knote *kn;
+ int i;
+ int err = 0;
+ struct filedesc *fdp = p->p_fd;
+ unsigned long nknotes = 0;
+ unsigned long buflen = bufsize / sizeof(struct kevent_extinfo);
+ struct kevent_extinfo *kqext = NULL;
+ /* arbitrary upper limit to cap kernel memory usage, copyout size, etc. */
+ buflen = min(buflen, PROC_PIDFDKQUEUE_KNOTES_MAX);
- m = m_get(M_DONTWAIT, MT_DATA);
- if (m == 0)
- return ENOBUFS;
+ kqext = kalloc(buflen * sizeof(struct kevent_extinfo));
+ if (kqext == NULL) {
+ err = ENOMEM;
+ goto out;
+ }
+ bzero(kqext, buflen * sizeof(struct kevent_extinfo));
- ev = mtod(m, struct kern_event_msg *);
- total_size = KEV_MSG_HEADER_SIZE;
+ proc_fdlock(p);
+ for (i = 0; i < fdp->fd_knlistsize; i++) {
+ kn = SLIST_FIRST(&fdp->fd_knlist[i]);
+ nknotes = kevent_extinfo_emit(kq, kn, kqext, buflen, nknotes);
+ }
+ proc_fdunlock(p);
- tmp = (char *) &ev->event_data[0];
- for (i = 0; i < 5; i++) {
- if (event_msg->dv[i].data_length == 0)
- break;
+ if (fdp->fd_knhashmask != 0) {
+ for (i = 0; i < (int)fdp->fd_knhashmask + 1; i++) {
+ kqhash_lock(p);
+ kn = SLIST_FIRST(&fdp->fd_knhash[i]);
+ nknotes = kevent_extinfo_emit(kq, kn, kqext, buflen, nknotes);
+ kqhash_unlock(p);
+ }
+ }
- 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;
- }
+ assert(bufsize >= sizeof(struct kevent_extinfo) * min(buflen, nknotes));
+ err = copyout(kqext, ubuf, sizeof(struct kevent_extinfo) * min(buflen, nknotes));
+out:
+ if (kqext) {
+ kfree(kqext, buflen * sizeof(struct kevent_extinfo));
+ kqext = NULL;
+ }
- 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;
+ if (!err) {
+ *retval = min(nknotes, PROC_PIDFDKQUEUE_KNOTES_MAX);
+ }
+ return err;
+}
- m->m_len = total_size;
- for (ev_pcb = LIST_FIRST(&kern_event_head);
- ev_pcb;
- ev_pcb = LIST_NEXT(ev_pcb, ev_link)) {
+static unsigned int
+klist_copy_udata(struct klist *list, uint64_t *buf,
+ unsigned int buflen, unsigned int nknotes)
+{
+ struct kevent_internal_s *kev;
+ struct knote *kn;
+ SLIST_FOREACH(kn, list, kn_link) {
+ if (nknotes < buflen) {
+ struct kqueue *kq = knote_get_kq(kn);
+ kqlock(kq);
+ kev = &(kn->kn_kevent);
+ buf[nknotes] = kev->udata;
+ kqunlock(kq);
+ }
+ /* we return total number of knotes, which may be more than requested */
+ nknotes++;
+ }
- if (ev_pcb->vendor_code_filter != KEV_ANY_VENDOR) {
- if (ev_pcb->vendor_code_filter != ev->vendor_code)
- continue;
+ return nknotes;
+}
- if (ev_pcb->class_filter != KEV_ANY_CLASS) {
- if (ev_pcb->class_filter != ev->kev_class)
- continue;
+static unsigned int
+kqlist_copy_dynamicids(__assert_only proc_t p, struct kqlist *list,
+ uint64_t *buf, unsigned int buflen, unsigned int nids)
+{
+ kqhash_lock_held(p);
+ struct kqworkloop *kqwl;
+ SLIST_FOREACH(kqwl, list, kqwl_hashlink) {
+ if (nids < buflen) {
+ buf[nids] = kqwl->kqwl_dynamicid;
+ }
+ nids++;
+ }
+ return nids;
+}
- if ((ev_pcb->subclass_filter != KEV_ANY_SUBCLASS) &&
- (ev_pcb->subclass_filter != ev->kev_subclass))
- continue;
- }
- }
+int
+kevent_proc_copy_uptrs(void *proc, uint64_t *buf, int bufsize)
+{
+ proc_t p = (proc_t)proc;
+ struct filedesc *fdp = p->p_fd;
+ unsigned int nuptrs = 0;
+ unsigned long buflen = bufsize / sizeof(uint64_t);
- m2 = m_copym(m, 0, m->m_len, M_NOWAIT);
- if (m2 == 0) {
- m_free(m);
- return ENOBUFS;
- }
+ if (buflen > 0) {
+ assert(buf != NULL);
+ }
- sbappendrecord(&ev_pcb->ev_socket->so_rcv, m2);
- sorwakeup(ev_pcb->ev_socket);
- }
+ proc_fdlock(p);
+ for (int i = 0; i < fdp->fd_knlistsize; i++) {
+ nuptrs = klist_copy_udata(&fdp->fd_knlist[i], buf, buflen, nuptrs);
+ }
+ knhash_lock(p);
+ proc_fdunlock(p);
+ if (fdp->fd_knhashmask != 0) {
+ for (int i = 0; i < (int)fdp->fd_knhashmask + 1; i++) {
+ nuptrs = klist_copy_udata(&fdp->fd_knhash[i], buf, buflen, nuptrs);
+ }
+ }
+ knhash_unlock(p);
+ kqhash_lock(p);
+ if (fdp->fd_kqhashmask != 0) {
+ for (int i = 0; i < (int)fdp->fd_kqhashmask + 1; i++) {
+ nuptrs = kqlist_copy_dynamicids(p, &fdp->fd_kqhash[i], buf, buflen,
+ nuptrs);
+ }
+ }
+ kqhash_unlock(p);
- m_free(m);
- return 0;
+ return (int)nuptrs;
}
+static void
+kevent_set_return_to_kernel_user_tsd(proc_t p, thread_t thread)
+{
+ uint64_t ast_addr;
+ bool proc_is_64bit = !!(p->p_flag & P_LP64);
+ size_t user_addr_size = proc_is_64bit ? 8 : 4;
+ uint32_t ast_flags32 = 0;
+ uint64_t ast_flags64 = 0;
+ struct uthread *ut = get_bsdthread_info(thread);
+
+ if (ut->uu_kqr_bound != NULL) {
+ ast_flags64 |= R2K_WORKLOOP_PENDING_EVENTS;
+ }
+
+ if (ast_flags64 == 0) {
+ return;
+ }
+
+ if (!(p->p_flag & P_LP64)) {
+ ast_flags32 = (uint32_t)ast_flags64;
+ assert(ast_flags64 < 0x100000000ull);
+ }
+
+ ast_addr = thread_rettokern_addr(thread);
+ if (ast_addr == 0) {
+ return;
+ }
+
+ if (copyout((proc_is_64bit ? (void *)&ast_flags64 : (void *)&ast_flags32),
+ (user_addr_t)ast_addr,
+ user_addr_size) != 0) {
+ printf("pid %d (tid:%llu): copyout of return_to_kernel ast flags failed with "
+ "ast_addr = %llu\n", p->p_pid, thread_tid(current_thread()), ast_addr);
+ }
+}
-int kev_control(so, cmd, data, ifp, p)
- struct socket *so;
- u_long cmd;
- caddr_t data;
- register struct ifnet *ifp;
- struct proc *p;
+void
+kevent_ast(thread_t thread, uint16_t bits)
{
- struct kev_request *kev_req = (struct kev_request *) data;
- int stat = 0;
- struct kern_event_pcb *ev_pcb;
- u_long *id_value = (u_long *) data;
+ proc_t p = current_proc();
+ if (bits & AST_KEVENT_REDRIVE_THREADREQ) {
+ workq_kern_threadreq_redrive(p, WORKQ_THREADREQ_CAN_CREATE_THREADS);
+ }
+ if (bits & AST_KEVENT_RETURN_TO_KERNEL) {
+ kevent_set_return_to_kernel_user_tsd(p, thread);
+ }
+}
- switch (cmd) {
+#if DEVELOPMENT || DEBUG
- case SIOCGKEVID:
- *id_value = static_event_id;
- break;
+#define KEVENT_SYSCTL_BOUND_ID 1
- case SIOCSKEVFILT:
- ev_pcb = (struct kern_event_pcb *) so->so_pcb;
- ev_pcb->vendor_code_filter = kev_req->vendor_code;
- ev_pcb->class_filter = kev_req->kev_class;
- ev_pcb->subclass_filter = kev_req->kev_subclass;
- break;
+static int
+kevent_sysctl SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg2)
+ uintptr_t type = (uintptr_t)arg1;
+ uint64_t bound_id = 0;
- case SIOCGKEVFILT:
- ev_pcb = (struct kern_event_pcb *) so->so_pcb;
- kev_req->vendor_code = ev_pcb->vendor_code_filter;
- kev_req->kev_class = ev_pcb->class_filter;
- kev_req->kev_subclass = ev_pcb->subclass_filter;
- break;
+ if (type != KEVENT_SYSCTL_BOUND_ID) {
+ return EINVAL;
+ }
- default:
- return EOPNOTSUPP;
- }
+ if (req->newptr) {
+ return EINVAL;
+ }
- return 0;
-}
+ struct uthread *ut = get_bsdthread_info(current_thread());
+ if (!ut) {
+ return EFAULT;
+ }
+ struct kqrequest *kqr = ut->uu_kqr_bound;
+ if (kqr) {
+ if (kqr->kqr_state & KQR_WORKLOOP) {
+ bound_id = kqr_kqworkloop(kqr)->kqwl_dynamicid;
+ } else {
+ bound_id = -1;
+ }
+ }
-struct pr_usrreqs event_usrreqs = {
- pru_abort_notsupp, pru_accept_notsupp, kev_attach, pru_bind_notsupp, pru_connect_notsupp,
- pru_connect2_notsupp, kev_control, kev_detach, pru_disconnect_notsupp,
- pru_listen_notsupp, pru_peeraddr_notsupp, pru_rcvd_notsupp, pru_rcvoob_notsupp,
- pru_send_notsupp, pru_sense_null, pru_shutdown_notsupp, pru_sockaddr_notsupp,
- pru_sosend_notsupp, soreceive, sopoll
-};
+ return sysctl_io_number(req, bound_id, sizeof(bound_id), NULL, NULL);
+}
+SYSCTL_NODE(_kern, OID_AUTO, kevent, CTLFLAG_RW | CTLFLAG_LOCKED, 0,
+ "kevent information");
+SYSCTL_PROC(_kern_kevent, OID_AUTO, bound_id,
+ CTLTYPE_QUAD | CTLFLAG_RD | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+ (void *)KEVENT_SYSCTL_BOUND_ID,
+ sizeof(kqueue_id_t), kevent_sysctl, "Q",
+ "get the ID of the bound kqueue");
+#endif /* DEVELOPMENT || DEBUG */
projects / apple / xnu.git / blobdiff