X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/fe8ab488e9161c46dd9885d58fc52996dc0249ff..527f99514973766e9c0382a4d8550dfb00f54939:/bsd/kern/kern_event.c diff --git a/bsd/kern/kern_event.c b/bsd/kern/kern_event.c index 3b16c4ca0..12885133e 100644 --- a/bsd/kern/kern_event.c +++ b/bsd/kern/kern_event.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000-2014 Apple Inc. All rights reserved. + * Copyright (c) 2000-2017 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * @@ -55,6 +55,7 @@ * @(#)kern_event.c 1.0 (3/31/2000) */ #include +#include #include #include @@ -82,51 +83,72 @@ #include #include #include +#include +#include +#include +#include #include #include +#include +#include #include #include +#include #include +#include #include +#include +#include +#include #include +#include + #include "net/net_str_id.h" #include - -#if VM_PRESSURE_EVENTS -#include -#endif +#include #if CONFIG_MEMORYSTATUS #include #endif -MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); +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 */ + +#define KEV_EVTID(code) BSDDBG_CODE(DBG_BSD_KEVENT, (code)) + +/* + * JMM - this typedef needs to be unified with pthread_priority_t + * and mach_msg_priority_t. It also needs to be the same type + * everywhere. + */ +typedef int32_t qos_t; -#define KQ_EVENT NULL +MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); -static inline void kqlock(struct kqueue *kq); -static inline void kqunlock(struct kqueue *kq); +#define KQ_EVENT NO_EVENT64 -static int kqlock2knoteuse(struct kqueue *kq, struct knote *kn); -static int kqlock2knoteusewait(struct kqueue *kq, struct knote *kn); +#define KNUSE_NONE 0x0 +#define KNUSE_STEAL_DROP 0x1 +#define KNUSE_BOOST 0x2 +static int kqlock2knoteuse(struct kqueue *kq, struct knote *kn, int flags); static int kqlock2knotedrop(struct kqueue *kq, struct knote *kn); -static int knoteuse2kqlock(struct kqueue *kq, struct knote *kn); +static int kqlock2knotedetach(struct kqueue *kq, struct knote *kn, int flags); +static int knoteuse2kqlock(struct kqueue *kq, struct knote *kn, int flags); -static void kqueue_wakeup(struct kqueue *kq, int closed); static int kqueue_read(struct fileproc *fp, struct uio *uio, - int flags, vfs_context_t ctx); + int flags, vfs_context_t ctx); static int kqueue_write(struct fileproc *fp, struct uio *uio, - int flags, vfs_context_t ctx); + int flags, vfs_context_t ctx); static int kqueue_ioctl(struct fileproc *fp, u_long com, caddr_t data, - vfs_context_t ctx); -static int kqueue_select(struct fileproc *fp, int which, void *wql, - vfs_context_t ctx); + 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, - vfs_context_t ctx); + 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 = { @@ -140,172 +162,423 @@ static const struct fileops kqueueops = { .fo_drain = kqueue_drain, }; -static int kevent_internal(struct proc *p, int iskev64, user_addr_t changelist, - int nchanges, user_addr_t eventlist, int nevents, int fd, - user_addr_t utimeout, unsigned int flags, int32_t *retval); -static int kevent_copyin(user_addr_t *addrp, struct kevent64_s *kevp, - struct proc *p, int iskev64); -static int kevent_copyout(struct kevent64_s *kevp, user_addr_t *addrp, - struct proc *p, int iskev64); -char * kevent_description(struct kevent64_s *kevp, char *s, size_t n); - -static int kevent_callback(struct kqueue *kq, struct kevent64_s *kevp, - void *data); +static void kevent_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 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 *data, int *countp, struct proc *p); -static int kqueue_begin_processing(struct kqueue *kq); -static void kqueue_end_processing(struct kqueue *kq); -static int knote_process(struct knote *kn, kevent_callback_t callback, - void *data, struct kqtailq *inprocessp, struct proc *p); +static int kqueue_process(struct kqueue *kq, kevent_callback_t callback, void *callback_data, + struct filt_process_s *process_data, int *countp, struct proc *p); +static struct kqtailq *kqueue_get_base_queue(struct kqueue *kq, kq_index_t qos_index); +static struct kqtailq *kqueue_get_high_queue(struct kqueue *kq, kq_index_t qos_index); +static int kqueue_queue_empty(struct kqueue *kq, kq_index_t qos_index); + +static struct kqtailq *kqueue_get_suppressed_queue(struct kqueue *kq, kq_index_t qos_index); + +static void kqworkq_request_thread(struct kqworkq *kqwq, kq_index_t qos_index); +static void kqworkq_request_help(struct kqworkq *kqwq, kq_index_t qos_index); +static void kqworkq_update_override(struct kqworkq *kqwq, kq_index_t qos_index, kq_index_t override_index); +static void kqworkq_bind_thread_impl(struct kqworkq *kqwq, kq_index_t qos_index, thread_t thread, unsigned int flags); +static void kqworkq_unbind_thread(struct kqworkq *kqwq, kq_index_t qos_index, thread_t thread, unsigned int flags); +static struct kqrequest *kqworkq_get_request(struct kqworkq *kqwq, kq_index_t qos_index); + +enum { + KQWL_UO_NONE = 0, + KQWL_UO_OLD_OVERRIDE_IS_SYNC_UI = 0x1, + KQWL_UO_NEW_OVERRIDE_IS_SYNC_UI = 0x2, + KQWL_UO_UPDATE_SUPPRESS_SYNC_COUNTERS = 0x4, + KQWL_UO_UPDATE_OVERRIDE_LAZY = 0x8 +}; + +static void kqworkloop_update_override(struct kqworkloop *kqwl, kq_index_t qos_index, kq_index_t override_index, uint32_t flags); +static void kqworkloop_bind_thread_impl(struct kqworkloop *kqwl, thread_t thread, unsigned int flags); +static void kqworkloop_unbind_thread(struct kqworkloop *kqwl, thread_t thread, unsigned int flags); +static inline kq_index_t kqworkloop_combined_qos(struct kqworkloop *kqwl, boolean_t *); +static void kqworkloop_update_suppress_sync_count(struct kqrequest *kqr, uint32_t flags); +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, + /* + * 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 async 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_ASYNC_QOS, + /* + * The sync waiters QoS is the maximum QoS of any thread blocked on an + * EVFILT_WORKLOOP knote marked with the NOTE_WL_SYNC_WAIT bit. + * If there is no such knote, this QoS is 0. + */ + KQWL_UTQ_SET_SYNC_WAITERS_QOS, + 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 knote_process(struct knote *kn, kevent_callback_t callback, void *callback_data, + struct filt_process_s *process_data, struct proc *p); +#if 0 static void knote_put(struct knote *kn); -static int knote_fdpattach(struct knote *kn, struct filedesc *fdp, - struct proc *p); +#endif + +static int kq_add_knote(struct kqueue *kq, struct knote *kn, + struct kevent_internal_s *kev, struct proc *p, int *knoteuse_flags); +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 kq_remove_knote(struct kqueue *kq, struct knote *kn, struct proc *p, kn_status_t *kn_status, uint16_t *kq_state); + static void knote_drop(struct knote *kn, struct proc *p); -static void knote_activate(struct knote *kn, int); -static void knote_deactivate(struct knote *kn); -static void knote_enqueue(struct knote *kn); -static void knote_dequeue(struct knote *kn); static struct knote *knote_alloc(void); static void knote_free(struct knote *kn); -static int filt_fileattach(struct knote *kn); -static struct filterops file_filtops = { +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 kq_index_t knote_get_queue_index(struct knote *kn); +static struct kqtailq *knote_get_queue(struct knote *kn); +static kq_index_t knote_get_req_index(struct knote *kn); +static kq_index_t knote_get_qos_index(struct knote *kn); +static void knote_set_qos_index(struct knote *kn, kq_index_t qos_index); +static kq_index_t knote_get_qos_override_index(struct knote *kn); +static kq_index_t knote_get_sync_qos_override_index(struct knote *kn); +static void knote_set_qos_override_index(struct knote *kn, kq_index_t qos_index, boolean_t override_is_sync); +static void knote_set_qos_overcommit(struct knote *kn); + +static int filt_fileattach(struct knote *kn, struct kevent_internal_s *kev); +SECURITY_READ_ONLY_EARLY(static struct filterops) file_filtops = { .f_isfd = 1, .f_attach = filt_fileattach, }; static void filt_kqdetach(struct knote *kn); static int filt_kqueue(struct knote *kn, long hint); -static struct filterops kqread_filtops = { +static int filt_kqtouch(struct knote *kn, struct kevent_internal_s *kev); +static int filt_kqprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev); +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, }; /* placeholder for not-yet-implemented filters */ -static int filt_badattach(struct knote *kn); -static struct filterops bad_filtops = { +static int filt_badattach(struct knote *kn, struct kevent_internal_s *kev); +SECURITY_READ_ONLY_EARLY(static struct filterops) bad_filtops = { .f_attach = filt_badattach, }; -static int filt_procattach(struct knote *kn); +static int filt_procattach(struct knote *kn, struct kevent_internal_s *kev); static void filt_procdetach(struct knote *kn); static int filt_proc(struct knote *kn, long hint); -static struct filterops proc_filtops = { +static int filt_proctouch(struct knote *kn, struct kevent_internal_s *kev); +static int filt_procprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev); +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, }; -#if VM_PRESSURE_EVENTS -static int filt_vmattach(struct knote *kn); -static void filt_vmdetach(struct knote *kn); -static int filt_vm(struct knote *kn, long hint); -static struct filterops vm_filtops = { - .f_attach = filt_vmattach, - .f_detach = filt_vmdetach, - .f_event = filt_vm, -}; -#endif /* VM_PRESSURE_EVENTS */ - #if CONFIG_MEMORYSTATUS -extern struct filterops memorystatus_filtops; +extern const struct filterops memorystatus_filtops; #endif /* CONFIG_MEMORYSTATUS */ -extern struct filterops fs_filtops; - -extern struct filterops sig_filtops; - -/* Timer filter */ -static int filt_timerattach(struct knote *kn); -static void filt_timerdetach(struct knote *kn); -static int filt_timer(struct knote *kn, long hint); -static void filt_timertouch(struct knote *kn, struct kevent64_s *kev, - long type); -static struct filterops timer_filtops = { - .f_attach = filt_timerattach, - .f_detach = filt_timerdetach, - .f_event = filt_timer, - .f_touch = filt_timertouch, -}; - -/* Helpers */ -static void filt_timerexpire(void *knx, void *param1); -static int filt_timervalidate(struct knote *kn); -static void filt_timerupdate(struct knote *kn); -static void filt_timercancel(struct knote *kn); - -#define TIMER_RUNNING 0x1 -#define TIMER_CANCELWAIT 0x2 +extern const struct filterops fs_filtops; -static lck_mtx_t _filt_timerlock; -static void filt_timerlock(void); -static void filt_timerunlock(void); +extern const struct filterops sig_filtops; static zone_t knote_zone; +static zone_t kqfile_zone; +static zone_t kqworkq_zone; +static zone_t kqworkloop_zone; #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) -#if 0 -extern struct filterops aio_filtops; -#endif - /* Mach portset filter */ -extern struct filterops machport_filtops; +extern const struct filterops machport_filtops; /* User filter */ -static int filt_userattach(struct knote *kn); +static int filt_userattach(struct knote *kn, struct kevent_internal_s *kev); static void filt_userdetach(struct knote *kn); static int filt_user(struct knote *kn, long hint); -static void filt_usertouch(struct knote *kn, struct kevent64_s *kev, - long type); -static struct filterops user_filtops = { +static int filt_usertouch(struct knote *kn, struct kevent_internal_s *kev); +static int filt_userprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev); +SECURITY_READ_ONLY_EARLY(static struct filterops) user_filtops = { .f_attach = filt_userattach, .f_detach = filt_userdetach, .f_event = filt_user, .f_touch = filt_usertouch, + .f_process = filt_userprocess, +}; + +static lck_spin_t _filt_userlock; +static void filt_userlock(void); +static void filt_userunlock(void); + +/* Workloop filter */ +static bool filt_wlneeds_boost(struct kevent_internal_s *kev); +static int filt_wlattach(struct knote *kn, struct kevent_internal_s *kev); +static int filt_wlpost_attach(struct knote *kn, struct kevent_internal_s *kev); +static void filt_wldetach(struct knote *kn); +static int filt_wlevent(struct knote *kn, long hint); +static int filt_wltouch(struct knote *kn, struct kevent_internal_s *kev); +static int filt_wldrop_and_unlock(struct knote *kn, struct kevent_internal_s *kev); +static int filt_wlprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev); +SECURITY_READ_ONLY_EARLY(static struct filterops) workloop_filtops = { + .f_needs_boost = filt_wlneeds_boost, + .f_attach = filt_wlattach, + .f_post_attach = filt_wlpost_attach, + .f_detach = filt_wldetach, + .f_event = filt_wlevent, + .f_touch = filt_wltouch, + .f_drop_and_unlock = filt_wldrop_and_unlock, + .f_process = filt_wlprocess, }; +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 timer_filtops; + /* - * Table for all system-defined filters. + * + * 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. */ -static struct filterops *sysfilt_ops[] = { - &file_filtops, /* EVFILT_READ */ - &file_filtops, /* EVFILT_WRITE */ -#if 0 - &aio_filtops, /* EVFILT_AIO */ -#else - &bad_filtops, /* EVFILT_AIO */ -#endif - &file_filtops, /* EVFILT_VNODE */ - &proc_filtops, /* EVFILT_PROC */ - &sig_filtops, /* EVFILT_SIGNAL */ - &timer_filtops, /* EVFILT_TIMER */ - &machport_filtops, /* EVFILT_MACHPORT */ - &fs_filtops, /* EVFILT_FS */ - &user_filtops, /* EVFILT_USER */ - &bad_filtops, /* unused */ -#if VM_PRESSURE_EVENTS - &vm_filtops, /* EVFILT_VM */ -#else - &bad_filtops, /* EVFILT_VM */ -#endif - &file_filtops, /* EVFILT_SOCK */ +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, + &bad_filtops, + [~EVFILT_SOCK] = &file_filtops, #if CONFIG_MEMORYSTATUS - &memorystatus_filtops, /* EVFILT_MEMORYSTATUS */ + [~EVFILT_MEMORYSTATUS] = &memorystatus_filtops, #else - &bad_filtops, /* EVFILT_MEMORYSTATUS */ + [~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, }; +/* waitq prepost callback */ +void waitq_set__CALLING_PREPOST_HOOK__(void *kq_hook, void *knote_hook, int qos); + +#ifndef _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG +#define _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG 0x02000000 /* pthread event manager bit */ +#endif +#ifndef _PTHREAD_PRIORITY_OVERCOMMIT_FLAG +#define _PTHREAD_PRIORITY_OVERCOMMIT_FLAG 0x80000000 /* request overcommit threads */ +#endif +#ifndef _PTHREAD_PRIORITY_QOS_CLASS_MASK +#define _PTHREAD_PRIORITY_QOS_CLASS_MASK 0x003fff00 /* QoS class mask */ +#endif +#ifndef _PTHREAD_PRIORITY_QOS_CLASS_SHIFT_32 +#define _PTHREAD_PRIORITY_QOS_CLASS_SHIFT_32 8 +#endif + +static inline __kdebug_only +uintptr_t +kqr_thread_id(struct kqrequest *kqr) +{ + return (uintptr_t)thread_tid(kqr->kqr_thread); +} + +static inline +boolean_t is_workqueue_thread(thread_t thread) +{ + return (thread_get_tag(thread) & THREAD_TAG_WORKQUEUE); +} + +static inline +void knote_canonicalize_kevent_qos(struct knote *kn) +{ + struct kqueue *kq = knote_get_kq(kn); + unsigned long canonical; + + if ((kq->kq_state & (KQ_WORKQ | KQ_WORKLOOP)) == 0) + return; + + /* preserve manager and overcommit flags in this case */ + canonical = pthread_priority_canonicalize(kn->kn_qos, FALSE); + kn->kn_qos = (qos_t)canonical; +} + +static inline +kq_index_t qos_index_from_qos(struct knote *kn, qos_t qos, boolean_t propagation) +{ + struct kqueue *kq = knote_get_kq(kn); + kq_index_t qos_index; + unsigned long flags = 0; + + if ((kq->kq_state & (KQ_WORKQ | KQ_WORKLOOP)) == 0) + return QOS_INDEX_KQFILE; + + qos_index = (kq_index_t)thread_qos_from_pthread_priority( + (unsigned long)qos, &flags); + + if (kq->kq_state & KQ_WORKQ) { + /* workq kqueues support requesting a manager thread (non-propagation) */ + if (!propagation && (flags & _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG)) + return KQWQ_QOS_MANAGER; + } + + return qos_index; +} + +static inline +qos_t qos_from_qos_index(kq_index_t qos_index) +{ + /* should only happen for KQ_WORKQ */ + if (qos_index == KQWQ_QOS_MANAGER) + return _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG; + + if (qos_index == 0) + return THREAD_QOS_UNSPECIFIED; + + /* Should have support from pthread kext support */ + return (1 << (qos_index - 1 + + _PTHREAD_PRIORITY_QOS_CLASS_SHIFT_32)); +} + +/* kqr lock must be held */ +static inline +unsigned long pthread_priority_for_kqrequest( + struct kqrequest *kqr, + kq_index_t qos_index) +{ + unsigned long priority = qos_from_qos_index(qos_index); + if (kqr->kqr_state & KQR_THOVERCOMMIT) { + priority |= _PTHREAD_PRIORITY_OVERCOMMIT_FLAG; + } + return priority; +} + +static inline +kq_index_t qos_index_for_servicer(int qos_class, thread_t thread, int flags) +{ +#pragma unused(thread) + kq_index_t qos_index; + + if (flags & KEVENT_FLAG_WORKQ_MANAGER) + return KQWQ_QOS_MANAGER; + + qos_index = (kq_index_t)qos_class; + assert(qos_index > 0 && qos_index < KQWQ_QOS_MANAGER); + + return qos_index; +} + /* - * kqueue/note lock attributes and implementations + * kqueue/note lock implementations + * + * The kqueue lock guards the kq state, the state of its queues, + * and the kqueue-aware status and use counts of individual knotes. * - * kqueues have locks, while knotes have use counts - * Most of the knote state is guarded by the object lock. - * the knote "inuse" count and status use the kqueue lock. + * 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. */ lck_grp_attr_t * kq_lck_grp_attr; lck_grp_t * kq_lck_grp; @@ -317,55 +590,79 @@ kqlock(struct kqueue *kq) lck_spin_lock(&kq->kq_lock); } +static inline void +kqlock_held(__assert_only struct kqueue *kq) +{ + LCK_SPIN_ASSERT(&kq->kq_lock, LCK_ASSERT_OWNED); +} + static inline void kqunlock(struct kqueue *kq) { lck_spin_unlock(&kq->kq_lock); } +static inline void +knhash_lock(proc_t p) +{ + lck_mtx_lock(&p->p_fd->fd_knhashlock); +} + +static inline void +knhash_unlock(proc_t p) +{ + lck_mtx_unlock(&p->p_fd->fd_knhashlock); +} + + /* * Convert a kq lock to a knote use referece. * - * If the knote is being dropped, we can't get - * a use reference, so just return with it - * still locked. + * If the knote is being dropped, or has + * vanished, we can't get a use reference. + * Just return with it still locked. + * * - kq locked at entry * - unlock on exit if we get the use reference */ static int -kqlock2knoteuse(struct kqueue *kq, struct knote *kn) +kqlock2knoteuse(struct kqueue *kq, struct knote *kn, int flags) { - if (kn->kn_status & KN_DROPPING) + if (kn->kn_status & (KN_DROPPING | KN_VANISHED)) return (0); + + assert(kn->kn_status & KN_ATTACHED); kn->kn_inuse++; + if (flags & KNUSE_BOOST) { + set_thread_rwlock_boost(); + } kqunlock(kq); return (1); } /* - * Convert a kq lock to a knote use referece, - * but wait for attach and drop events to complete. - * - * If the knote is being dropped, we can't get - * a use reference, so just return with it - * still locked. * - kq locked at entry - * - kq always unlocked on exit + * - kq unlocked at exit */ -static int -kqlock2knoteusewait(struct kqueue *kq, struct knote *kn) +__disable_tail_calls +static wait_result_t +knoteusewait(struct kqueue *kq, struct knote *kn) { - if ((kn->kn_status & (KN_DROPPING | KN_ATTACHING)) != 0) { - kn->kn_status |= KN_USEWAIT; - wait_queue_assert_wait((wait_queue_t)kq->kq_wqs, - &kn->kn_status, THREAD_UNINT, 0); - kqunlock(kq); - thread_block(THREAD_CONTINUE_NULL); - return (0); - } - kn->kn_inuse++; + kn->kn_status |= KN_USEWAIT; + waitq_assert_wait64((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(&kn->kn_status), + THREAD_UNINT, TIMEOUT_WAIT_FOREVER); kqunlock(kq); - return (1); + return thread_block(THREAD_CONTINUE_NULL); +} + +static bool +knoteuse_needs_boost(struct knote *kn, struct kevent_internal_s *kev) +{ + if (knote_fops(kn)->f_needs_boost) { + return knote_fops(kn)->f_needs_boost(kev); + } + return false; } /* @@ -374,25 +671,111 @@ kqlock2knoteusewait(struct kqueue *kq, struct knote *kn) * Drop a use reference and wake any waiters if * this is the last one. * - * The exit return indicates if the knote is - * still alive - but the kqueue lock is taken - * unconditionally. + * If someone is trying to drop the knote, but the + * caller has events they must deliver, take + * responsibility for the drop later - and wake the + * other attempted dropper in a manner that informs + * him of the transfer of responsibility. + * + * The exit return indicates if the knote is still alive + * (or if not, the other dropper has been given the green + * light to drop it). + * + * The kqueue lock is re-taken unconditionally. */ static int -knoteuse2kqlock(struct kqueue *kq, struct knote *kn) +knoteuse2kqlock(struct kqueue *kq, struct knote *kn, int flags) { + int dropped = 0; + int steal_drop = (flags & KNUSE_STEAL_DROP); + kqlock(kq); + if (flags & KNUSE_BOOST) { + clear_thread_rwlock_boost(); + } + if (--kn->kn_inuse == 0) { + if ((kn->kn_status & KN_ATTACHING) != 0) { kn->kn_status &= ~KN_ATTACHING; } + if ((kn->kn_status & KN_USEWAIT) != 0) { + wait_result_t result; + + /* If we need to, try and steal the drop */ + if (kn->kn_status & KN_DROPPING) { + if (steal_drop && !(kn->kn_status & KN_STOLENDROP)) { + kn->kn_status |= KN_STOLENDROP; + } else { + dropped = 1; + } + } + + /* wakeup indicating if ANY USE stole the drop */ + result = (kn->kn_status & KN_STOLENDROP) ? + THREAD_RESTART : THREAD_AWAKENED; + kn->kn_status &= ~KN_USEWAIT; - wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, - &kn->kn_status, THREAD_AWAKENED); + waitq_wakeup64_all((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(&kn->kn_status), + result, + WAITQ_ALL_PRIORITIES); + } else { + /* should have seen use-wait if dropping with use refs */ + assert((kn->kn_status & (KN_DROPPING|KN_STOLENDROP)) == 0); } + + } else if (kn->kn_status & KN_DROPPING) { + /* not the last ref but want to steal a drop if present */ + if (steal_drop && ((kn->kn_status & KN_STOLENDROP) == 0)) { + kn->kn_status |= KN_STOLENDROP; + + /* but we now have to wait to be the last ref */ + knoteusewait(kq, kn); + kqlock(kq); + } else { + dropped = 1; + } + } + + return (!dropped); +} + +/* + * Convert a kq lock to a knote use reference + * (for the purpose of detaching AND vanishing it). + * + * If the knote is being dropped, we can't get + * a detach reference, so wait for the knote to + * finish dropping before returning. + * + * If the knote is being used for other purposes, + * we cannot detach it until those uses are done + * as well. Again, just wait for them to finish + * (caller will start over at lookup). + * + * - kq locked at entry + * - unlocked on exit + */ +static int +kqlock2knotedetach(struct kqueue *kq, struct knote *kn, int flags) +{ + if ((kn->kn_status & KN_DROPPING) || kn->kn_inuse) { + /* have to wait for dropper or current uses to go away */ + knoteusewait(kq, kn); + return (0); + } + assert((kn->kn_status & KN_VANISHED) == 0); + assert(kn->kn_status & KN_ATTACHED); + kn->kn_status &= ~KN_ATTACHED; + kn->kn_status |= KN_VANISHED; + if (flags & KNUSE_BOOST) { + clear_thread_rwlock_boost(); } - return ((kn->kn_status & KN_DROPPING) == 0); + kn->kn_inuse++; + kqunlock(kq); + return (1); } /* @@ -413,46 +796,51 @@ static int kqlock2knotedrop(struct kqueue *kq, struct knote *kn) { int oktodrop; + wait_result_t result; oktodrop = ((kn->kn_status & (KN_DROPPING | KN_ATTACHING)) == 0); + /* if another thread is attaching, they will become the dropping thread */ kn->kn_status |= KN_DROPPING; + knote_unsuppress(kn); + knote_dequeue(kn); if (oktodrop) { if (kn->kn_inuse == 0) { kqunlock(kq); return (oktodrop); } } - kn->kn_status |= KN_USEWAIT; - wait_queue_assert_wait((wait_queue_t)kq->kq_wqs, &kn->kn_status, - THREAD_UNINT, 0); - kqunlock(kq); - thread_block(THREAD_CONTINUE_NULL); - return (oktodrop); + result = knoteusewait(kq, kn); + /* THREAD_RESTART == another thread stole the knote drop */ + return (result == THREAD_AWAKENED); } +#if 0 /* * Release a knote use count reference. */ static void knote_put(struct knote *kn) { - struct kqueue *kq = kn->kn_kq; + struct kqueue *kq = knote_get_kq(kn); kqlock(kq); if (--kn->kn_inuse == 0) { if ((kn->kn_status & KN_USEWAIT) != 0) { kn->kn_status &= ~KN_USEWAIT; - wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, - &kn->kn_status, THREAD_AWAKENED); + waitq_wakeup64_all((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(&kn->kn_status), + THREAD_AWAKENED, + WAITQ_ALL_PRIORITIES); } } kqunlock(kq); } +#endif static int -filt_fileattach(struct knote *kn) +filt_fileattach(struct knote *kn, struct kevent_internal_s *kev) { - return (fo_kqfilter(kn->kn_fp, kn, vfs_context_current())); + return (fo_kqfilter(kn->kn_fp, kn, kev, vfs_context_current())); } #define f_flag f_fglob->fg_flag @@ -465,10 +853,11 @@ filt_fileattach(struct knote *kn) static void filt_kqdetach(struct knote *kn) { - struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; + struct kqfile *kqf = (struct kqfile *)kn->kn_fp->f_data; + struct kqueue *kq = &kqf->kqf_kqueue; kqlock(kq); - KNOTE_DETACH(&kq->kq_sel.si_note, kn); + KNOTE_DETACH(&kqf->kqf_sel.si_note, kn); kqunlock(kq); } @@ -477,24 +866,70 @@ static int filt_kqueue(struct knote *kn, __unused long hint) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; + int count; + + count = kq->kq_count; + return (count > 0); +} + +static int +filt_kqtouch(struct knote *kn, struct kevent_internal_s *kev) +{ +#pragma unused(kev) + struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; + int res; + + kqlock(kq); + kn->kn_data = kq->kq_count; + if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) + kn->kn_udata = kev->udata; + res = (kn->kn_data > 0); + + kqunlock(kq); + + return res; +} + +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; + kqlock(kq); kn->kn_data = kq->kq_count; - return (kn->kn_data > 0); + res = (kn->kn_data > 0); + if (res) { + *kev = kn->kn_kevent; + if (kn->kn_flags & EV_CLEAR) + kn->kn_data = 0; + } + kqunlock(kq); + + return res; } +#pragma mark EVFILT_PROC + static int -filt_procattach(struct knote *kn) +filt_procattach(struct knote *kn, __unused struct kevent_internal_s *kev) { struct proc *p; assert(PID_MAX < NOTE_PDATAMASK); - if ((kn->kn_sfflags & (NOTE_TRACK | NOTE_TRACKERR | NOTE_CHILD)) != 0) - return (ENOTSUP); + if ((kn->kn_sfflags & (NOTE_TRACK | NOTE_TRACKERR | NOTE_CHILD)) != 0) { + kn->kn_flags = EV_ERROR; + kn->kn_data = ENOTSUP; + return 0; + } p = proc_find(kn->kn_id); if (p == NULL) { - return (ESRCH); + kn->kn_flags = EV_ERROR; + kn->kn_data = ESRCH; + return 0; } const int NoteExitStatusBits = NOTE_EXIT | NOTE_EXITSTATUS; @@ -511,12 +946,13 @@ filt_procattach(struct knote *kn) break; /* parent-in-waiting => ok */ proc_rele(p); - return (EACCES); + kn->kn_flags = EV_ERROR; + kn->kn_data = EACCES; + return 0; } while (0); proc_klist_lock(); - kn->kn_flags |= EV_CLEAR; /* automatically set */ kn->kn_ptr.p_proc = p; /* store the proc handle */ KNOTE_ATTACH(&p->p_klist, kn); @@ -525,9 +961,14 @@ filt_procattach(struct knote *kn) proc_rele(p); + /* + * only captures edge-triggered events after this point + * so it can't already be fired. + */ return (0); } + /* * The knote may be attached to a different process, which may exit, * leaving nothing for the knote to be attached to. In that case, @@ -552,178 +993,240 @@ filt_procdetach(struct knote *kn) 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 Freeing up * bits in hint for filt_proc + * + * mask off extra data */ - /* hint is 0 when called from above */ - if (hint != 0) { - u_int event; - - /* ALWAYS CALLED WITH proc_klist_lock when (hint != 0) */ + event = (u_int)hint & NOTE_PCTRLMASK; - /* - * mask off extra data - */ - event = (u_int)hint & NOTE_PCTRLMASK; - - /* - * termination lifecycle events can happen while a debugger - * has reparented a process, in which case notifications - * should be quashed except to the tracing parent. When - * the debugger reaps the child (either via wait4(2) or - * process exit), the child will be reparented to the original - * parent and these knotes re-fired. - */ - if (event & NOTE_EXIT) { - if ((kn->kn_ptr.p_proc->p_oppid != 0) - && (kn->kn_kq->kq_p->p_pid != kn->kn_ptr.p_proc->p_ppid)) { - /* - * This knote is not for the current ptrace(2) parent, ignore. - */ - return 0; - } - } + /* + * 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)) { + /* + * This knote is not for the current ptrace(2) parent, ignore. + */ + return 0; + } + } - /* - * if the user is interested in this event, record it. - */ - if (kn->kn_sfflags & event) - kn->kn_fflags |= event; + /* + * if the user is interested in this event, record it. + */ + if (kn->kn_sfflags & event) + kn->kn_fflags |= event; #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wdeprecated-declarations" - if ((event == NOTE_REAP) || ((event == NOTE_EXIT) && !(kn->kn_sfflags & NOTE_REAP))) { - kn->kn_flags |= (EV_EOF | EV_ONESHOT); - } + if ((event == NOTE_REAP) || ((event == NOTE_EXIT) && !(kn->kn_sfflags & NOTE_REAP))) { + kn->kn_flags |= (EV_EOF | EV_ONESHOT); + } #pragma clang diagnostic pop - /* - * The kernel has a wrapper in place that returns the same data - * as is collected here, in kn_data. Any changes to how - * NOTE_EXITSTATUS and NOTE_EXIT_DETAIL are collected - * should also be reflected in the proc_pidnoteexit() wrapper. - */ - if (event == NOTE_EXIT) { - kn->kn_data = 0; - if ((kn->kn_sfflags & NOTE_EXITSTATUS) != 0) { - kn->kn_fflags |= NOTE_EXITSTATUS; - kn->kn_data |= (hint & NOTE_PDATAMASK); - } - if ((kn->kn_sfflags & NOTE_EXIT_DETAIL) != 0) { - kn->kn_fflags |= NOTE_EXIT_DETAIL; - if ((kn->kn_ptr.p_proc->p_lflag & - P_LTERM_DECRYPTFAIL) != 0) { - kn->kn_data |= NOTE_EXIT_DECRYPTFAIL; - } - if ((kn->kn_ptr.p_proc->p_lflag & - P_LTERM_JETSAM) != 0) { - kn->kn_data |= NOTE_EXIT_MEMORY; - switch (kn->kn_ptr.p_proc->p_lflag & - P_JETSAM_MASK) { - case P_JETSAM_VMPAGESHORTAGE: - kn->kn_data |= NOTE_EXIT_MEMORY_VMPAGESHORTAGE; - break; - case P_JETSAM_VMTHRASHING: - kn->kn_data |= NOTE_EXIT_MEMORY_VMTHRASHING; - break; - case P_JETSAM_FCTHRASHING: - kn->kn_data |= NOTE_EXIT_MEMORY_FCTHRASHING; - break; - case P_JETSAM_VNODE: - kn->kn_data |= NOTE_EXIT_MEMORY_VNODE; - break; - case P_JETSAM_HIWAT: - kn->kn_data |= NOTE_EXIT_MEMORY_HIWAT; - break; - case P_JETSAM_PID: - kn->kn_data |= NOTE_EXIT_MEMORY_PID; - break; - case P_JETSAM_IDLEEXIT: - kn->kn_data |= NOTE_EXIT_MEMORY_IDLE; - break; - } - } - if ((kn->kn_ptr.p_proc->p_csflags & - CS_KILLED) != 0) { - kn->kn_data |= NOTE_EXIT_CSERROR; + /* + * The kernel has a wrapper in place that returns the same data + * as is collected here, in kn_data. Any changes to how + * NOTE_EXITSTATUS and NOTE_EXIT_DETAIL are collected + * should also be reflected in the proc_pidnoteexit() wrapper. + */ + if (event == NOTE_EXIT) { + kn->kn_data = 0; + if ((kn->kn_sfflags & NOTE_EXITSTATUS) != 0) { + kn->kn_fflags |= NOTE_EXITSTATUS; + kn->kn_data |= (hint & NOTE_PDATAMASK); + } + if ((kn->kn_sfflags & NOTE_EXIT_DETAIL) != 0) { + kn->kn_fflags |= NOTE_EXIT_DETAIL; + if ((kn->kn_ptr.p_proc->p_lflag & + P_LTERM_DECRYPTFAIL) != 0) { + kn->kn_data |= NOTE_EXIT_DECRYPTFAIL; + } + if ((kn->kn_ptr.p_proc->p_lflag & + P_LTERM_JETSAM) != 0) { + kn->kn_data |= NOTE_EXIT_MEMORY; + switch (kn->kn_ptr.p_proc->p_lflag & P_JETSAM_MASK) { + case P_JETSAM_VMPAGESHORTAGE: + kn->kn_data |= NOTE_EXIT_MEMORY_VMPAGESHORTAGE; + break; + case P_JETSAM_VMTHRASHING: + kn->kn_data |= NOTE_EXIT_MEMORY_VMTHRASHING; + break; + case P_JETSAM_FCTHRASHING: + kn->kn_data |= NOTE_EXIT_MEMORY_FCTHRASHING; + break; + case P_JETSAM_VNODE: + kn->kn_data |= NOTE_EXIT_MEMORY_VNODE; + break; + case P_JETSAM_HIWAT: + kn->kn_data |= NOTE_EXIT_MEMORY_HIWAT; + break; + case P_JETSAM_PID: + kn->kn_data |= NOTE_EXIT_MEMORY_PID; + break; + case P_JETSAM_IDLEEXIT: + kn->kn_data |= NOTE_EXIT_MEMORY_IDLE; + break; } } + if ((kn->kn_ptr.p_proc->p_csflags & + CS_KILLED) != 0) { + kn->kn_data |= NOTE_EXIT_CSERROR; + } } } - /* atomic check, no locking need when called from above */ + /* if we have any matching state, activate the knote */ return (kn->kn_fflags != 0); } -#if VM_PRESSURE_EVENTS -/* - * Virtual memory kevents - * - * author: Matt Jacobson [matthew_jacobson@apple.com] - */ - static int -filt_vmattach(struct knote *kn) +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; + if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) + kn->kn_udata = kev->udata; + + /* restrict the current results to the (smaller?) set of new interest */ /* - * The note will be cleared once the information has been flushed to - * the client. If there is still pressure, we will be re-alerted. + * For compatibility with previous implementations, we leave kn_fflags + * as they were before. */ - kn->kn_flags |= EV_CLEAR; - return (vm_knote_register(kn)); -} + //kn->kn_fflags &= kn->kn_sfflags; -static void -filt_vmdetach(struct knote *kn) -{ - vm_knote_unregister(kn); + res = (kn->kn_fflags != 0); + + proc_klist_unlock(); + + return res; } static int -filt_vm(struct knote *kn, long hint) +filt_procprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev) { - /* hint == 0 means this is just an alive? check (always true) */ - if (hint != 0) { - const pid_t pid = (pid_t)hint; - if ((kn->kn_sfflags & NOTE_VM_PRESSURE) && - (kn->kn_kq->kq_p->p_pid == pid)) { - kn->kn_fflags |= NOTE_VM_PRESSURE; - } - } +#pragma unused(data) + int res; - return (kn->kn_fflags != 0); + 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; } -#endif /* VM_PRESSURE_EVENTS */ + + +#pragma mark EVFILT_TIMER + /* - * filt_timervalidate - process data from user + * Values stored in the knote at rest (using Mach absolute time units) * - * Converts to either interval or deadline format. + * 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_data fire count + */ + +static lck_mtx_t _filt_timerlock; + +static void filt_timerlock(void) { lck_mtx_lock(&_filt_timerlock); } +static void filt_timerunlock(void) { lck_mtx_unlock(&_filt_timerlock); } + +static inline void filt_timer_assert_locked(void) +{ + LCK_MTX_ASSERT(&_filt_timerlock, LCK_MTX_ASSERT_OWNED); +} + +/* state flags stored in kn_hookid */ +#define TIMER_RUNNING 0x1 +#define TIMER_CANCELWAIT 0x2 + +/* + * filt_timervalidate - process data from user * - * The saved-data field in the knote contains the - * time value. The saved filter-flags indicates - * the unit of measurement. + * Sets up the deadline, interval, and leeway from the provided user data * - * After validation, either the saved-data field - * contains the interval in absolute time, or ext[0] - * contains the expected deadline. If that deadline - * is in the past, ext[0] is 0. + * Input: + * kn_sdata timer deadline or interval time + * kn_sfflags style of timer, unit of measurement * - * Returns EINVAL for unrecognized units of time. + * Output: + * kn_sdata either interval in abstime or 0 if non-repeating timer + * ext[0] fire deadline in abs/cont time + * (or 0 if NOTE_ABSOLUTE and deadline is in past) * - * Timer filter lock is held. + * Returns: + * EINVAL Invalid user data parameters * + * Called with timer filter lock held. */ static int filt_timervalidate(struct knote *kn) { + /* + * There are 4 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. + */ + + filt_timer_assert_locked(); + uint64_t multiplier; - uint64_t raw = 0; - switch (kn->kn_sfflags & (NOTE_SECONDS|NOTE_USECONDS|NOTE_NSECONDS)) { + boolean_t use_abstime = FALSE; + + switch (kn->kn_sfflags & (NOTE_SECONDS|NOTE_USECONDS|NOTE_NSECONDS|NOTE_MACHTIME)) { case NOTE_SECONDS: multiplier = NSEC_PER_SEC; break; @@ -733,6 +1236,10 @@ filt_timervalidate(struct knote *kn) 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; @@ -740,75 +1247,124 @@ filt_timervalidate(struct knote *kn) return (EINVAL); } - /* transform the slop delta(leeway) in kn_ext[1] if passed to same time scale */ - if(kn->kn_sfflags & NOTE_LEEWAY){ - nanoseconds_to_absolutetime((uint64_t)kn->kn_ext[1] * multiplier, &raw); - kn->kn_ext[1] = raw; - } + /* transform the leeway in kn_ext[1] to same time scale */ + if (kn->kn_sfflags & NOTE_LEEWAY) { + uint64_t leeway_abs; - nanoseconds_to_absolutetime((uint64_t)kn->kn_sdata * multiplier, &raw); + if (use_abstime) { + leeway_abs = (uint64_t)kn->kn_ext[1]; + } else { + uint64_t leeway_ns; + if (os_mul_overflow((uint64_t)kn->kn_ext[1], multiplier, &leeway_ns)) + return (ERANGE); - kn->kn_ext[0] = 0; - kn->kn_sdata = 0; + nanoseconds_to_absolutetime(leeway_ns, &leeway_abs); + } - if (kn->kn_sfflags & NOTE_ABSOLUTE) { - clock_sec_t seconds; - clock_nsec_t nanoseconds; - uint64_t now; + kn->kn_ext[1] = leeway_abs; + } - clock_get_calendar_nanotime(&seconds, &nanoseconds); - nanoseconds_to_absolutetime((uint64_t)seconds * NSEC_PER_SEC + - nanoseconds, &now); + if (kn->kn_sfflags & NOTE_ABSOLUTE) { + uint64_t deadline_abs; - if (raw < now) { - /* time has already passed */ - kn->kn_ext[0] = 0; + if (use_abstime) { + deadline_abs = (uint64_t)kn->kn_sdata; } else { - raw -= now; - clock_absolutetime_interval_to_deadline(raw, - &kn->kn_ext[0]); - } - } else { - kn->kn_sdata = raw; - } + uint64_t calendar_deadline_ns; - return (0); -} + if (os_mul_overflow((uint64_t)kn->kn_sdata, multiplier, &calendar_deadline_ns)) + return (ERANGE); -/* - * filt_timerupdate - compute the next deadline - * - * Repeating timers store their interval in kn_sdata. Absolute - * timers have already calculated the deadline, stored in ext[0]. - * - * On return, the next deadline (or zero if no deadline is needed) - * is stored in kn_ext[0]. - * - * Timer filter lock is held. - */ -static void -filt_timerupdate(struct knote *kn) -{ - /* if there's no interval, deadline is just in kn_ext[0] */ - if (kn->kn_sdata == 0) - return; + /* calendar_deadline_ns is in nanoseconds since the epoch */ - /* if timer hasn't fired before, fire in interval nsecs */ - if (kn->kn_ext[0] == 0) { - clock_absolutetime_interval_to_deadline(kn->kn_sdata, - &kn->kn_ext[0]); - } else { + 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; + + 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 (kn->kn_sfflags & NOTE_MACH_CONTINUOUS_TIME) + clock_continuoustime_interval_to_deadline(interval_abs, + &deadline_abs); + else + clock_absolutetime_interval_to_deadline(interval_abs, + &deadline_abs); + } else { + deadline_abs = 0; /* cause immediate expiration */ + } + } + + kn->kn_ext[0] = deadline_abs; + kn->kn_sdata = 0; /* NOTE_ABSOLUTE is non-repeating */ + } else if (kn->kn_sdata < 0) { /* - * If timer has fired before, schedule the next pop - * relative to the last intended deadline. + * 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 could check for whether the deadline has expired, - * but the thread call layer can handle that. + * We now skip the power-wasting hot spin phase and go straight to the idle phase. */ - kn->kn_ext[0] += kn->kn_sdata; + + kn->kn_sdata = 0; /* non-repeating */ + kn->kn_ext[0] = 0; /* expire immediately */ + } else { + uint64_t interval_abs = 0; + + if (use_abstime) { + interval_abs = (uint64_t)kn->kn_sdata; + } else { + uint64_t interval_ns; + if (os_mul_overflow((uint64_t)kn->kn_sdata, multiplier, &interval_ns)) + return (ERANGE); + + nanoseconds_to_absolutetime(interval_ns, &interval_abs); + } + + uint64_t deadline = 0; + + if (kn->kn_sfflags & NOTE_MACH_CONTINUOUS_TIME) + clock_continuoustime_interval_to_deadline(interval_abs, &deadline); + else + clock_absolutetime_interval_to_deadline(interval_abs, &deadline); + + kn->kn_sdata = interval_abs; /* default to a repeating timer */ + kn->kn_ext[0] = deadline; } + + return (0); } + + + /* * filt_timerexpire - the timer callout routine * @@ -831,13 +1387,18 @@ filt_timerexpire(void *knx, __unused void *spare) /* no "object" for timers, so fake a list */ SLIST_INIT(&timer_list); SLIST_INSERT_HEAD(&timer_list, kn, kn_selnext); + KNOTE(&timer_list, 1); /* if someone is waiting for timer to pop */ if (kn->kn_hookid & TIMER_CANCELWAIT) { - struct kqueue *kq = kn->kn_kq; - wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, &kn->kn_hook, - THREAD_AWAKENED); + struct kqueue *kq = knote_get_kq(kn); + waitq_wakeup64_all((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(&kn->kn_hook), + THREAD_AWAKENED, + WAITQ_ALL_PRIORITIES); + + kn->kn_hookid &= ~TIMER_CANCELWAIT; } filt_timerunlock(); @@ -846,84 +1407,152 @@ filt_timerexpire(void *knx, __unused void *spare) /* * Cancel a running timer (or wait for the pop). * Timer filter lock is held. + * May drop and retake the timer filter lock. */ static void filt_timercancel(struct knote *kn) { - struct kqueue *kq = kn->kn_kq; - thread_call_t callout = kn->kn_hook; - boolean_t cancelled; + filt_timer_assert_locked(); - if (kn->kn_hookid & TIMER_RUNNING) { - /* cancel the callout if we can */ - cancelled = thread_call_cancel(callout); - if (cancelled) { - kn->kn_hookid &= ~TIMER_RUNNING; - } else { - /* we have to wait for the expire routine. */ - kn->kn_hookid |= TIMER_CANCELWAIT; - wait_queue_assert_wait((wait_queue_t)kq->kq_wqs, - &kn->kn_hook, THREAD_UNINT, 0); - filt_timerunlock(); - thread_block(THREAD_CONTINUE_NULL); - filt_timerlock(); - assert((kn->kn_hookid & TIMER_RUNNING) == 0); - } + assert((kn->kn_hookid & TIMER_CANCELWAIT) == 0); + + /* if no timer, then we're good */ + if ((kn->kn_hookid & TIMER_RUNNING) == 0) + return; + + thread_call_t callout = (thread_call_t)kn->kn_hook; + + /* cancel the callout if we can */ + if (thread_call_cancel(callout)) { + kn->kn_hookid &= ~TIMER_RUNNING; + return; } + + /* cancel failed, we have to wait for the in-flight expire routine */ + + kn->kn_hookid |= TIMER_CANCELWAIT; + + struct kqueue *kq = knote_get_kq(kn); + + waitq_assert_wait64((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(&kn->kn_hook), + THREAD_UNINT, TIMEOUT_WAIT_FOREVER); + + filt_timerunlock(); + thread_block(THREAD_CONTINUE_NULL); + filt_timerlock(); + + assert((kn->kn_hookid & TIMER_CANCELWAIT) == 0); + assert((kn->kn_hookid & TIMER_RUNNING) == 0); +} + +static void +filt_timerarm(struct knote *kn) +{ + filt_timer_assert_locked(); + + assert((kn->kn_hookid & TIMER_RUNNING) == 0); + + thread_call_t callout = (thread_call_t)kn->kn_hook; + + 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; + + 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; + + thread_call_enter_delayed_with_leeway(callout, NULL, + deadline, leeway, + timer_flags); + + kn->kn_hookid |= TIMER_RUNNING; +} + +/* + * Does this knote need a timer armed for it, or should it be ready immediately? + */ +static boolean_t +filt_timer_is_ready(struct knote *kn) +{ + uint64_t now; + + if (kn->kn_sfflags & NOTE_MACH_CONTINUOUS_TIME) + now = mach_continuous_time(); + else + now = mach_absolute_time(); + + uint64_t deadline = kn->kn_ext[0]; + + if (deadline < now) + return TRUE; + else + return FALSE; } /* * Allocate a thread call for the knote's lifetime, and kick off the timer. */ static int -filt_timerattach(struct knote *kn) +filt_timerattach(struct knote *kn, __unused struct kevent_internal_s *kev) { thread_call_t callout; int error; - callout = thread_call_allocate(filt_timerexpire, kn); - if (NULL == callout) - return (ENOMEM); + callout = thread_call_allocate_with_options(filt_timerexpire, + (thread_call_param_t)kn, THREAD_CALL_PRIORITY_HIGH, + THREAD_CALL_OPTIONS_ONCE); + + if (NULL == callout) { + kn->kn_flags = EV_ERROR; + kn->kn_data = ENOMEM; + return 0; + } filt_timerlock(); - error = filt_timervalidate(kn); - if (error != 0) { + + if ((error = filt_timervalidate(kn)) != 0) { + kn->kn_flags = EV_ERROR; + kn->kn_data = error; filt_timerunlock(); - return (error); + + __assert_only boolean_t freed = thread_call_free(callout); + assert(freed); + return 0; } kn->kn_hook = (void*)callout; kn->kn_hookid = 0; + kn->kn_flags |= EV_CLEAR; - /* absolute=EV_ONESHOT */ + /* NOTE_ABSOLUTE implies EV_ONESHOT */ if (kn->kn_sfflags & NOTE_ABSOLUTE) kn->kn_flags |= EV_ONESHOT; - filt_timerupdate(kn); - if (kn->kn_ext[0]) { - kn->kn_flags |= EV_CLEAR; - unsigned int timer_flags = 0; - if (kn->kn_sfflags & NOTE_CRITICAL) - timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL; - else if (kn->kn_sfflags & NOTE_BACKGROUND) - timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND; - else - timer_flags |= THREAD_CALL_DELAY_USER_NORMAL; - - if (kn->kn_sfflags & NOTE_LEEWAY) - timer_flags |= THREAD_CALL_DELAY_LEEWAY; + boolean_t timer_ready = FALSE; - thread_call_enter_delayed_with_leeway(callout, NULL, - kn->kn_ext[0], kn->kn_ext[1], timer_flags); - - kn->kn_hookid |= TIMER_RUNNING; - } else { - /* fake immediate */ + if ((timer_ready = filt_timer_is_ready(kn))) { + /* cause immediate expiration */ kn->kn_data = 1; + } else { + filt_timerarm(kn); } filt_timerunlock(); - return (0); + + return timer_ready; } /* @@ -941,158 +1570,231 @@ filt_timerdetach(struct knote *kn) filt_timerunlock(); - thread_call_free(callout); + __assert_only boolean_t freed = thread_call_free(callout); + assert(freed); } - - +/* + * filt_timerevent - post events to a timer knote + * + * Called in the context of filt_timerexpire with + * the filt_timerlock held + */ static int -filt_timer(struct knote *kn, long hint) +filt_timerevent(struct knote *kn, __unused long hint) { - int result; + filt_timer_assert_locked(); - if (hint) { - /* real timer pop -- timer lock held by filt_timerexpire */ - kn->kn_data++; - - if (((kn->kn_hookid & TIMER_CANCELWAIT) == 0) && - ((kn->kn_flags & EV_ONESHOT) == 0)) { + kn->kn_data = 1; + return (1); +} - /* evaluate next time to fire */ - filt_timerupdate(kn); +/* + * 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 +filt_timertouch( + struct knote *kn, + struct kevent_internal_s *kev) +{ + int error; - if (kn->kn_ext[0]) { - unsigned int timer_flags = 0; + filt_timerlock(); - /* keep the callout and re-arm */ - if (kn->kn_sfflags & NOTE_CRITICAL) - timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL; - else if (kn->kn_sfflags & NOTE_BACKGROUND) - timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND; - else - timer_flags |= THREAD_CALL_DELAY_USER_NORMAL; + /* + * cancel current call - drops and retakes lock + * TODO: not safe against concurrent touches? + */ + filt_timercancel(kn); - if (kn->kn_sfflags & NOTE_LEEWAY) - timer_flags |= THREAD_CALL_DELAY_LEEWAY; + /* clear if the timer had previously fired, the user no longer wants to see it */ + kn->kn_data = 0; - thread_call_enter_delayed_with_leeway(kn->kn_hook, NULL, - kn->kn_ext[0], kn->kn_ext[1], timer_flags); + /* capture the new values used to compute deadline */ + kn->kn_sdata = kev->data; + kn->kn_sfflags = kev->fflags; + kn->kn_ext[0] = kev->ext[0]; + kn->kn_ext[1] = kev->ext[1]; - kn->kn_hookid |= TIMER_RUNNING; - } - } + if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) + kn->kn_udata = kev->udata; - return (1); + /* recalculate deadline */ + error = filt_timervalidate(kn); + if (error) { + /* no way to report error, so mark it in the knote */ + kn->kn_flags |= EV_ERROR; + kn->kn_data = error; + filt_timerunlock(); + return 1; } - /* user-query */ - filt_timerlock(); + boolean_t timer_ready = FALSE; - result = (kn->kn_data != 0); + if ((timer_ready = filt_timer_is_ready(kn))) { + /* cause immediate expiration */ + kn->kn_data = 1; + } else { + filt_timerarm(kn); + } filt_timerunlock(); - return (result); + return timer_ready; } - /* - * filt_timertouch - update knote with new user input + * filt_timerprocess - query state of knote and snapshot event data * - * 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). + * 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 void -filt_timertouch(struct knote *kn, struct kevent64_s *kev, long type) +static int +filt_timerprocess( + struct knote *kn, + __unused struct filt_process_s *data, + struct kevent_internal_s *kev) { - int error; filt_timerlock(); - switch (type) { - case EVENT_REGISTER: - /* cancel current call */ - filt_timercancel(kn); + if (kn->kn_data == 0 || (kn->kn_hookid & TIMER_CANCELWAIT)) { + /* + * kn_data = 0: + * The timer hasn't yet fired, so there's nothing to deliver + * TIMER_CANCELWAIT: + * touch is in the middle of canceling the timer, + * so don't deliver or re-arm anything + * + * This can happen if a touch resets a timer that had fired + * without being processed + */ + filt_timerunlock(); + return 0; + } - /* recalculate deadline */ - kn->kn_sdata = kev->data; - kn->kn_sfflags = kev->fflags; - kn->kn_ext[0] = kev->ext[0]; - kn->kn_ext[1] = kev->ext[1]; + if (kn->kn_sdata != 0 && ((kn->kn_flags & EV_ERROR) == 0)) { + /* + * 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... + */ - error = filt_timervalidate(kn); - if (error) { - /* no way to report error, so mark it in the knote */ - kn->kn_flags |= EV_ERROR; - kn->kn_data = error; - break; - } + /* The timer better have had expired... */ + assert((kn->kn_hookid & TIMER_RUNNING) == 0); - /* start timer if necessary */ - filt_timerupdate(kn); + uint64_t now; - if (kn->kn_ext[0]) { - unsigned int timer_flags = 0; - if (kn->kn_sfflags & NOTE_CRITICAL) - timer_flags |= THREAD_CALL_DELAY_USER_CRITICAL; - else if (kn->kn_sfflags & NOTE_BACKGROUND) - timer_flags |= THREAD_CALL_DELAY_USER_BACKGROUND; - else - timer_flags |= THREAD_CALL_DELAY_USER_NORMAL; + if (kn->kn_sfflags & NOTE_MACH_CONTINUOUS_TIME) + now = mach_continuous_time(); + else + now = mach_absolute_time(); - if (kn->kn_sfflags & NOTE_LEEWAY) - timer_flags |= THREAD_CALL_DELAY_LEEWAY; + uint64_t first_deadline = kn->kn_ext[0]; + uint64_t interval_abs = kn->kn_sdata; + uint64_t orig_arm_time = first_deadline - interval_abs; - thread_call_enter_delayed_with_leeway(kn->kn_hook, NULL, - kn->kn_ext[0], kn->kn_ext[1], timer_flags); + assert(now > orig_arm_time); + assert(now > first_deadline); - kn->kn_hookid |= TIMER_RUNNING; - } else { - /* pretend the timer has fired */ - kn->kn_data = 1; - } + uint64_t elapsed = now - orig_arm_time; - break; + uint64_t num_fired = elapsed / interval_abs; - case EVENT_PROCESS: - /* reset the timer pop count in kn_data */ - *kev = kn->kn_kevent; - kev->ext[0] = 0; - kn->kn_data = 0; - if (kn->kn_flags & EV_CLEAR) - kn->kn_fflags = 0; - break; - default: - panic("%s: - invalid type (%ld)", __func__, type); - break; + /* + * 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. + * + * An unsuccessful touch would: + * disarm the timer + * clear kn_data + * clear kn_sdata + * set EV_ERROR + * all of which will prevent this code from running. + */ + assert(num_fired > 0); + + /* report how many intervals have elapsed to the user */ + kn->kn_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; + + filt_timerarm(kn); + } } + /* + * 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? */ + + /* we have delivered the event, reset the timer pop count */ + kn->kn_data = 0; + filt_timerunlock(); + return 1; } +SECURITY_READ_ONLY_EARLY(static struct filterops) timer_filtops = { + .f_attach = filt_timerattach, + .f_detach = filt_timerdetach, + .f_event = filt_timerevent, + .f_touch = filt_timertouch, + .f_process = filt_timerprocess, +}; + + +#pragma mark EVFILT_USER + + static void -filt_timerlock(void) +filt_userlock(void) { - lck_mtx_lock(&_filt_timerlock); + lck_spin_lock(&_filt_userlock); } static void -filt_timerunlock(void) +filt_userunlock(void) { - lck_mtx_unlock(&_filt_timerlock); + lck_spin_unlock(&_filt_userlock); } static int -filt_userattach(struct knote *kn) +filt_userattach(struct knote *kn, __unused struct kevent_internal_s *kev) { /* EVFILT_USER knotes are not attached to anything in the kernel */ + /* Cant discover this knote until after attach - so no lock needed */ kn->kn_hook = NULL; - if (kn->kn_fflags & NOTE_TRIGGER) { + if (kn->kn_sfflags & NOTE_TRIGGER) { kn->kn_hookid = 1; } else { kn->kn_hookid = 0; } - return (0); + return (kn->kn_hookid); } static void @@ -1102,1418 +1804,5948 @@ filt_userdetach(__unused struct knote *kn) } static int -filt_user(struct knote *kn, __unused long hint) +filt_user( + __unused struct knote *kn, + __unused long hint) { - return (kn->kn_hookid); + panic("filt_user"); + return 0; } -static void -filt_usertouch(struct knote *kn, struct kevent64_s *kev, long type) +static int +filt_usertouch( + struct knote *kn, + struct kevent_internal_s *kev) { uint32_t ffctrl; - switch (type) { - case EVENT_REGISTER: - if (kev->fflags & NOTE_TRIGGER) { - kn->kn_hookid = 1; - } + int fflags; + int active; - ffctrl = kev->fflags & NOTE_FFCTRLMASK; - kev->fflags &= NOTE_FFLAGSMASK; - switch (ffctrl) { - case NOTE_FFNOP: - break; - case NOTE_FFAND: - OSBitAndAtomic(kev->fflags, &kn->kn_sfflags); - break; - case NOTE_FFOR: - OSBitOrAtomic(kev->fflags, &kn->kn_sfflags); - break; - case NOTE_FFCOPY: - kn->kn_sfflags = kev->fflags; - break; - } - kn->kn_sdata = kev->data; + filt_userlock(); + + ffctrl = kev->fflags & NOTE_FFCTRLMASK; + fflags = kev->fflags & NOTE_FFLAGSMASK; + switch (ffctrl) { + case NOTE_FFNOP: break; - case EVENT_PROCESS: - *kev = kn->kn_kevent; - kev->fflags = (volatile UInt32)kn->kn_sfflags; - kev->data = kn->kn_sdata; - if (kn->kn_flags & EV_CLEAR) { - kn->kn_hookid = 0; - kn->kn_data = 0; - kn->kn_fflags = 0; - } + case NOTE_FFAND: + kn->kn_sfflags &= fflags; break; - default: - panic("%s: - invalid type (%ld)", __func__, type); + case NOTE_FFOR: + kn->kn_sfflags |= fflags; break; + case NOTE_FFCOPY: + kn->kn_sfflags = fflags; + break; + } + kn->kn_sdata = kev->data; + + if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0) + kn->kn_udata = kev->udata; + + if (kev->fflags & NOTE_TRIGGER) { + kn->kn_hookid = 1; } + active = kn->kn_hookid; + + filt_userunlock(); + + return (active); } -/* - * JMM - placeholder for not-yet-implemented filters - */ static int -filt_badattach(__unused struct knote *kn) +filt_userprocess( + struct knote *kn, + __unused struct filt_process_s *data, + struct kevent_internal_s *kev) { - return (ENOTSUP); -} + filt_userlock(); -struct kqueue * -kqueue_alloc(struct proc *p) -{ - struct filedesc *fdp = p->p_fd; - struct kqueue *kq; + if (kn->kn_hookid == 0) { + filt_userunlock(); + return 0; + } - MALLOC_ZONE(kq, struct kqueue *, sizeof (struct kqueue), M_KQUEUE, - M_WAITOK); - if (kq != NULL) { - wait_queue_set_t wqs; - - wqs = wait_queue_set_alloc(SYNC_POLICY_FIFO | - SYNC_POLICY_PREPOST); - if (wqs != NULL) { - bzero(kq, sizeof (struct kqueue)); - lck_spin_init(&kq->kq_lock, kq_lck_grp, kq_lck_attr); - TAILQ_INIT(&kq->kq_head); - kq->kq_wqs = wqs; - kq->kq_p = p; - } else { - FREE_ZONE(kq, sizeof (struct kqueue), M_KQUEUE); - } - } - - if (fdp->fd_knlistsize < 0) { - proc_fdlock(p); - if (fdp->fd_knlistsize < 0) - fdp->fd_knlistsize = 0; /* this process has had a kq */ - proc_fdunlock(p); + *kev = kn->kn_kevent; + kev->fflags = (volatile UInt32)kn->kn_sfflags; + kev->data = kn->kn_sdata; + if (kn->kn_flags & EV_CLEAR) { + kn->kn_hookid = 0; + kn->kn_data = 0; + kn->kn_fflags = 0; } + filt_userunlock(); - return (kq); + return 1; } +#pragma mark EVFILT_WORKLOOP + +#if DEBUG || DEVELOPMENT /* - * 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. + * see src/queue_internal.h in libdispatch */ -void -kqueue_dealloc(struct kqueue *kq) -{ - struct proc *p = kq->kq_p; - struct filedesc *fdp = p->p_fd; - struct knote *kn; - int i; - - proc_fdlock(p); - for (i = 0; i < fdp->fd_knlistsize; i++) { - kn = SLIST_FIRST(&fdp->fd_knlist[i]); - while (kn != NULL) { - if (kq == kn->kn_kq) { - kqlock(kq); - proc_fdunlock(p); - /* drop it ourselves or wait */ - if (kqlock2knotedrop(kq, kn)) { - kn->kn_fop->f_detach(kn); - knote_drop(kn, p); - } - proc_fdlock(p); - /* start over at beginning of list */ - kn = SLIST_FIRST(&fdp->fd_knlist[i]); - continue; - } - kn = SLIST_NEXT(kn, kn_link); - } - } - if (fdp->fd_knhashmask != 0) { - for (i = 0; i < (int)fdp->fd_knhashmask + 1; i++) { - kn = SLIST_FIRST(&fdp->fd_knhash[i]); - while (kn != NULL) { - if (kq == kn->kn_kq) { - kqlock(kq); - proc_fdunlock(p); - /* drop it ourselves or wait */ - if (kqlock2knotedrop(kq, kn)) { - kn->kn_fop->f_detach(kn); - knote_drop(kn, p); - } - proc_fdlock(p); - /* start over at beginning of list */ - kn = SLIST_FIRST(&fdp->fd_knhash[i]); - continue; - } - kn = SLIST_NEXT(kn, kn_link); - } - } - } - proc_fdunlock(p); +#define DISPATCH_QUEUE_ENQUEUED 0x1ull +#endif - /* - * before freeing the wait queue set for this kqueue, - * make sure it is unlinked from all its containing (select) sets. - */ - wait_queue_unlink_all((wait_queue_t)kq->kq_wqs); - wait_queue_set_free(kq->kq_wqs); - lck_spin_destroy(&kq->kq_lock, kq_lck_grp); - FREE_ZONE(kq, sizeof (struct kqueue), M_KQUEUE); +static inline void +filt_wllock(struct kqworkloop *kqwl) +{ + lck_mtx_lock(&kqwl->kqwl_statelock); } -int -kqueue_body(struct proc *p, fp_allocfn_t fp_zalloc, void *cra, int32_t *retval) +static inline void +filt_wlunlock(struct kqworkloop *kqwl) { - struct kqueue *kq; - struct fileproc *fp; - int fd, error; + lck_mtx_unlock(&kqwl->kqwl_statelock); +} - error = falloc_withalloc(p, - &fp, &fd, vfs_context_current(), fp_zalloc, cra); - if (error) { - return (error); - } +static inline void +filt_wlheld(__assert_only struct kqworkloop *kqwl) +{ + LCK_MTX_ASSERT(&kqwl->kqwl_statelock, LCK_MTX_ASSERT_OWNED); +} - kq = kqueue_alloc(p); - if (kq == NULL) { - fp_free(p, fd, fp); - return (ENOMEM); - } +#define WL_OWNER_SUSPENDED ((thread_t)(~0ull)) /* special owner when suspended */ - fp->f_flag = FREAD | FWRITE; - fp->f_ops = &kqueueops; - fp->f_data = kq; +static inline bool +filt_wlowner_is_valid(thread_t owner) +{ + return owner != THREAD_NULL && owner != WL_OWNER_SUSPENDED; +} - proc_fdlock(p); - *fdflags(p, fd) |= UF_EXCLOSE; - procfdtbl_releasefd(p, fd, NULL); - fp_drop(p, fd, fp, 1); - proc_fdunlock(p); +static inline bool +filt_wlshould_end_ownership(struct kqworkloop *kqwl, + struct kevent_internal_s *kev, int error) +{ + thread_t owner = kqwl->kqwl_owner; + return (error == 0 || error == ESTALE) && + (kev->fflags & NOTE_WL_END_OWNERSHIP) && + (owner == current_thread() || owner == WL_OWNER_SUSPENDED); +} - *retval = fd; - return (error); +static inline bool +filt_wlshould_update_ownership(struct kevent_internal_s *kev, int error) +{ + return error == 0 && (kev->fflags & NOTE_WL_DISCOVER_OWNER) && + kev->ext[EV_EXTIDX_WL_ADDR]; } -int -kqueue(struct proc *p, __unused struct kqueue_args *uap, int32_t *retval) +static inline bool +filt_wlshould_set_async_qos(struct kevent_internal_s *kev, int error, + kq_index_t async_qos) { - return (kqueue_body(p, fileproc_alloc_init, NULL, retval)); + if (error != 0) { + return false; + } + if (async_qos != THREAD_QOS_UNSPECIFIED) { + return true; + } + if ((kev->fflags & NOTE_WL_THREAD_REQUEST) && (kev->flags & EV_DELETE)) { + /* see filt_wlprocess() */ + return true; + } + return false; } +__result_use_check static int -kevent_copyin(user_addr_t *addrp, struct kevent64_s *kevp, struct proc *p, - int iskev64) +filt_wlupdateowner(struct kqworkloop *kqwl, struct kevent_internal_s *kev, + int error, kq_index_t async_qos) { - int advance; - int error; + struct kqrequest *kqr = &kqwl->kqwl_request; + thread_t cur_owner, new_owner, extra_thread_ref = THREAD_NULL; + kq_index_t cur_override = THREAD_QOS_UNSPECIFIED; + kq_index_t old_owner_override = THREAD_QOS_UNSPECIFIED; + boolean_t ipc_override_is_sync = false; + boolean_t old_owner_override_is_sync = false; + int action = KQWL_UTQ_NONE; - if (iskev64) { - advance = sizeof (struct kevent64_s); - error = copyin(*addrp, (caddr_t)kevp, advance); - } else if (IS_64BIT_PROCESS(p)) { - struct user64_kevent kev64; - bzero(kevp, sizeof (struct kevent64_s)); + filt_wlheld(kqwl); - advance = sizeof (kev64); - error = copyin(*addrp, (caddr_t)&kev64, advance); - if (error) - return (error); - kevp->ident = kev64.ident; - kevp->filter = kev64.filter; - kevp->flags = kev64.flags; - kevp->fflags = kev64.fflags; - kevp->data = kev64.data; - kevp->udata = kev64.udata; + /* + * The owner is only changed under both the filt_wllock and the + * kqwl_req_lock. Looking at it with either one held is fine. + */ + cur_owner = kqwl->kqwl_owner; + if (filt_wlshould_end_ownership(kqwl, kev, error)) { + new_owner = THREAD_NULL; + } else if (filt_wlshould_update_ownership(kev, error)) { + /* + * Decipher the owner port name, and translate accordingly. + * The low 2 bits were borrowed for other flags, so mask them off. + */ + uint64_t udata = kev->ext[EV_EXTIDX_WL_VALUE]; + mach_port_name_t new_owner_name = (mach_port_name_t)udata & ~0x3; + if (new_owner_name != MACH_PORT_NULL) { + new_owner_name = ipc_entry_name_mask(new_owner_name); + } + + if (MACH_PORT_VALID(new_owner_name)) { + new_owner = port_name_to_thread(new_owner_name); + if (new_owner == THREAD_NULL) + return EOWNERDEAD; + extra_thread_ref = new_owner; + } else if (new_owner_name == MACH_PORT_DEAD) { + new_owner = WL_OWNER_SUSPENDED; + } else { + /* + * We never want to learn a new owner that is NULL. + * Ownership should be ended with END_OWNERSHIP. + */ + new_owner = cur_owner; + } } else { - struct user32_kevent kev32; - bzero(kevp, sizeof (struct kevent64_s)); + new_owner = cur_owner; + } - advance = sizeof (kev32); - error = copyin(*addrp, (caddr_t)&kev32, advance); - if (error) - return (error); - kevp->ident = (uintptr_t)kev32.ident; - kevp->filter = kev32.filter; - kevp->flags = kev32.flags; - kevp->fflags = kev32.fflags; - kevp->data = (intptr_t)kev32.data; - kevp->udata = CAST_USER_ADDR_T(kev32.udata); + if (filt_wlshould_set_async_qos(kev, error, async_qos)) { + action = KQWL_UTQ_SET_ASYNC_QOS; } - if (!error) - *addrp += advance; - return (error); + if (cur_owner == new_owner && action == KQWL_UTQ_NONE) { + goto out; + } + + kqwl_req_lock(kqwl); + + /* If already tracked as servicer, don't track as owner */ + if ((kqr->kqr_state & KQR_BOUND) && new_owner == kqr->kqr_thread) { + kqwl->kqwl_owner = 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_override = kqworkloop_combined_qos(kqwl, &ipc_override_is_sync); + old_owner_override = kqr->kqr_dsync_owner_qos; + old_owner_override_is_sync = kqr->kqr_owner_override_is_sync; + + if (filt_wlowner_is_valid(new_owner)) { + /* override it before we drop the old */ + if (cur_override != THREAD_QOS_UNSPECIFIED) { + thread_add_ipc_override(new_owner, cur_override); + } + if (ipc_override_is_sync) { + thread_add_sync_ipc_override(new_owner); + } + /* Update the kqr to indicate that owner has sync ipc override */ + kqr->kqr_dsync_owner_qos = cur_override; + kqr->kqr_owner_override_is_sync = ipc_override_is_sync; + thread_starts_owning_workloop(new_owner); + if ((kqr->kqr_state & (KQR_THREQUESTED | KQR_BOUND)) == KQR_THREQUESTED) { + if (action == KQWL_UTQ_NONE) { + action = KQWL_UTQ_REDRIVE_EVENTS; + } + } + } else if (new_owner == THREAD_NULL) { + kqr->kqr_dsync_owner_qos = THREAD_QOS_UNSPECIFIED; + kqr->kqr_owner_override_is_sync = false; + if ((kqr->kqr_state & (KQR_THREQUESTED | KQR_WAKEUP)) == KQR_WAKEUP) { + if (action == KQWL_UTQ_NONE) { + action = KQWL_UTQ_REDRIVE_EVENTS; + } + } + } + } + + if (action != KQWL_UTQ_NONE) { + kqworkloop_update_threads_qos(kqwl, action, async_qos); + } + + kqwl_req_unlock(kqwl); + + /* Now that we are unlocked, drop the override and ref on old owner */ + if (new_owner != cur_owner && filt_wlowner_is_valid(cur_owner)) { + if (old_owner_override != THREAD_QOS_UNSPECIFIED) { + thread_drop_ipc_override(cur_owner); + } + if (old_owner_override_is_sync) { + thread_drop_sync_ipc_override(cur_owner); + } + thread_ends_owning_workloop(cur_owner); + thread_deallocate(cur_owner); + } + +out: + if (extra_thread_ref) { + thread_deallocate(extra_thread_ref); + } + return error; } static int -kevent_copyout(struct kevent64_s *kevp, user_addr_t *addrp, struct proc *p, - int iskev64) +filt_wldebounce( + struct kqworkloop *kqwl, + struct kevent_internal_s *kev, + int default_result) { - int advance; + user_addr_t addr = CAST_USER_ADDR_T(kev->ext[EV_EXTIDX_WL_ADDR]); + uint64_t udata; int error; - if (iskev64) { - advance = sizeof (struct kevent64_s); - error = copyout((caddr_t)kevp, *addrp, advance); - } else if (IS_64BIT_PROCESS(p)) { - struct user64_kevent kev64; + /* we must have the workloop state mutex held */ + filt_wlheld(kqwl); - /* - * 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; + /* Do we have a debounce address to work with? */ + if (addr) { + uint64_t kdata = kev->ext[EV_EXTIDX_WL_VALUE]; + uint64_t mask = kev->ext[EV_EXTIDX_WL_MASK]; - kev64.filter = kevp->filter; - kev64.flags = kevp->flags; - kev64.fflags = kevp->fflags; - kev64.data = (int64_t) kevp->data; - kev64.udata = kevp->udata; - advance = sizeof (kev64); - error = copyout((caddr_t)&kev64, *addrp, advance); - } else { - struct user32_kevent kev32; + error = copyin_word(addr, &udata, sizeof(udata)); + if (error) { + return error; + } - kev32.ident = (uint32_t)kevp->ident; - kev32.filter = kevp->filter; - kev32.flags = kevp->flags; - kev32.fflags = kevp->fflags; - kev32.data = (int32_t)kevp->data; - kev32.udata = kevp->udata; - advance = sizeof (kev32); - error = copyout((caddr_t)&kev32, *addrp, advance); + /* update state as copied in */ + kev->ext[EV_EXTIDX_WL_VALUE] = udata; + + /* If the masked bits don't match, reject it as stale */ + if ((udata & mask) != (kdata & mask)) { + return ESTALE; + } + +#if DEBUG || DEVELOPMENT + if ((kev->fflags & NOTE_WL_THREAD_REQUEST) && !(kev->flags & EV_DELETE)) { + if ((udata & DISPATCH_QUEUE_ENQUEUED) == 0 && + (udata >> 48) != 0 && (udata >> 48) != 0xffff) { + panic("kevent: workloop %#016llx is not enqueued " + "(kev:%p dq_state:%#016llx)", kev->udata, kev, udata); + } + } +#endif } - if (!error) - *addrp += advance; - return (error); + + return default_result; } /* - * kevent_continue - continue a kevent syscall after blocking - * - * assume we inherit a use count on the kq fileglob. + * 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 void -kevent_continue(__unused struct kqueue *kq, void *data, int error) +static inline void +filt_wlremember_last_update( + __assert_only struct kqworkloop *kqwl, + struct knote *kn, + struct kevent_internal_s *kev, + int error) { - struct _kevent *cont_args; - struct fileproc *fp; - int32_t *retval; - int noutputs; - int fd; - struct proc *p = current_proc(); - - cont_args = (struct _kevent *)data; - noutputs = cont_args->eventout; - retval = cont_args->retval; - fd = cont_args->fd; - fp = cont_args->fp; - - fp_drop(p, fd, fp, 0); - - /* don't restart after signals... */ - if (error == ERESTART) - error = EINTR; - else if (error == EWOULDBLOCK) - error = 0; - if (error == 0) - *retval = noutputs; - unix_syscall_return(error); + filt_wlheld(kqwl); + kn->kn_fflags = kev->fflags; + kn->kn_data = error; + memcpy(kn->kn_ext, kev->ext, sizeof(kev->ext)); } /* - * kevent - [syscall] register and wait for kernel events - * + * Return which operations on EVFILT_WORKLOOP need to be protected against + * knoteusewait() causing priority inversions. */ -int -kevent(struct proc *p, struct kevent_args *uap, int32_t *retval) +static bool +filt_wlneeds_boost(struct kevent_internal_s *kev) { - return (kevent_internal(p, - 0, - uap->changelist, - uap->nchanges, - uap->eventlist, - uap->nevents, - uap->fd, - uap->timeout, - 0, /* no flags from old kevent() call */ - retval)); -} + if (kev == NULL) { + /* + * this is an f_process() usecount, and it can cause a drop to wait + */ + return true; + } + if (kev->fflags & NOTE_WL_THREAD_REQUEST) { + /* + * All operations on thread requests may starve drops or re-attach of + * the same knote, all of them need boosts. None of what we do under + * thread-request usecount holds blocks anyway. + */ + return true; + } + if (kev->fflags & NOTE_WL_SYNC_WAIT) { + /* + * this may call filt_wlwait() and we don't want to hold any boost when + * woken up, this would cause background threads contending on + * dispatch_sync() to wake up at 64 and be preempted immediately when + * this drops. + */ + return false; + } -int -kevent64(struct proc *p, struct kevent64_args *uap, int32_t *retval) -{ - return (kevent_internal(p, - 1, - uap->changelist, - uap->nchanges, - uap->eventlist, - uap->nevents, - uap->fd, - uap->timeout, - uap->flags, - retval)); + /* + * SYNC_WAIT knotes when deleted don't need to be rushed, there's no + * detach/reattach race with these ever. In addition to this, when the + * SYNC_WAIT knote is dropped, the caller is no longer receiving the + * workloop overrides if any, and we'd rather schedule other threads than + * him, he's not possibly stalling anything anymore. + */ + return (kev->flags & EV_DELETE) == 0; } static int -kevent_internal(struct proc *p, int iskev64, user_addr_t changelist, - int nchanges, user_addr_t ueventlist, int nevents, int fd, - user_addr_t utimeout, __unused unsigned int flags, - int32_t *retval) +filt_wlattach(struct knote *kn, struct kevent_internal_s *kev) { - struct _kevent *cont_args; - uthread_t ut; - struct kqueue *kq; - struct fileproc *fp; - struct kevent64_s kev; - int error, noutputs; - struct timeval atv; + struct kqueue *kq = knote_get_kq(kn); + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + int error = 0; + kq_index_t qos_index = 0; - /* convert timeout to absolute - if we have one */ - if (utimeout != USER_ADDR_NULL) { - struct timeval rtv; - if (IS_64BIT_PROCESS(p)) { - struct user64_timespec ts; - error = copyin(utimeout, &ts, sizeof(ts)); - if ((ts.tv_sec & 0xFFFFFFFF00000000ull) != 0) - error = EINVAL; - else - TIMESPEC_TO_TIMEVAL(&rtv, &ts); - } else { - struct user32_timespec ts; - error = copyin(utimeout, &ts, sizeof(ts)); - TIMESPEC_TO_TIMEVAL(&rtv, &ts); + if ((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; + + kqwl_req_lock(kqwl); + kev->fflags = 0; + if (kqr->kqr_dsync_waiters) { + kev->fflags |= NOTE_WL_SYNC_WAIT; } - if (error) - return (error); - if (itimerfix(&rtv)) - return (EINVAL); - getmicrouptime(&atv); - timevaladd(&atv, &rtv); + if (kqr->kqr_qos_index) { + kev->fflags |= NOTE_WL_THREAD_REQUEST; + } + if (kqwl->kqwl_owner == WL_OWNER_SUSPENDED) { + kev->ext[0] = ~0ull; + } else { + 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]; + kqwl_req_unlock(kqwl); + error = EBUSY; + goto out; + } +#endif + + /* Some simple validation */ + 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 = qos_index_from_qos(kn, kn->kn_qos, FALSE); + if (qos_index < THREAD_QOS_MAINTENANCE || + qos_index > THREAD_QOS_USER_INTERACTIVE) { + error = ERANGE; + goto out; + } + break; + case NOTE_WL_SYNC_WAIT: + case NOTE_WL_SYNC_WAKE: + if (kq->kq_state & KQ_NO_WQ_THREAD) { + error = ENOTSUP; + goto out; + } + 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; + } + + filt_wllock(kqwl); + kn->kn_hook = NULL; + + if (command == NOTE_WL_THREAD_REQUEST && 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. + * + * Note: kqr_qos_index is always set with the wllock held, so we + * don't need to take the kqr lock. + */ + error = EALREADY; } else { - atv.tv_sec = 0; - atv.tv_usec = 0; + /* Make sure user and kernel are in agreement on important state */ + error = filt_wldebounce(kqwl, kev, 0); } - /* get a usecount for the kq itself */ - if ((error = fp_getfkq(p, fd, &fp, &kq)) != 0) - return (error); + error = filt_wlupdateowner(kqwl, kev, error, qos_index); + filt_wlunlock(kqwl); +out: + if (error) { + kn->kn_flags |= EV_ERROR; + /* If userland wants ESTALE to be hidden, fail the attach anyway */ + if (error == ESTALE && (kn->kn_sfflags & NOTE_WL_IGNORE_ESTALE)) { + error = 0; + } + kn->kn_data = error; + return 0; + } - /* each kq should only be used for events of one type */ - kqlock(kq); - if (kq->kq_state & (KQ_KEV32 | KQ_KEV64)) { - if (((iskev64 && (kq->kq_state & KQ_KEV32)) || - (!iskev64 && (kq->kq_state & KQ_KEV64)))) { + /* Just attaching the thread request successfully will fire it */ + return command == NOTE_WL_THREAD_REQUEST; +} + +__attribute__((noinline,not_tail_called)) +static int +filt_wlwait(struct kqworkloop *kqwl, + struct knote *kn, + struct kevent_internal_s *kev) +{ + filt_wlheld(kqwl); + assert((kn->kn_sfflags & NOTE_WL_SYNC_WAKE) == 0); + + /* + * Hint to the wakeup side that this thread is waiting. Also used by + * stackshot for waitinfo. + */ + kn->kn_hook = current_thread(); + + thread_set_pending_block_hint(current_thread(), kThreadWaitWorkloopSyncWait); + + wait_result_t wr = assert_wait(kn, THREAD_ABORTSAFE); + + if (wr == THREAD_WAITING) { + kq_index_t qos_index = qos_index_from_qos(kn, kev->qos, TRUE); + struct kqrequest *kqr = &kqwl->kqwl_request; + + thread_t thread_to_handoff = THREAD_NULL; /* holds +1 thread ref */ + + thread_t kqwl_owner = kqwl->kqwl_owner; + if (filt_wlowner_is_valid(kqwl_owner)) { + thread_reference(kqwl_owner); + thread_to_handoff = kqwl_owner; + } + + kqwl_req_lock(kqwl); + + if (qos_index) { + assert(kqr->kqr_dsync_waiters < UINT16_MAX); + kqr->kqr_dsync_waiters++; + if (qos_index > kqr->kqr_dsync_waiters_qos) { + kqworkloop_update_threads_qos(kqwl, + KQWL_UTQ_SET_SYNC_WAITERS_QOS, qos_index); + } + } + + if ((kqr->kqr_state & KQR_BOUND) && thread_to_handoff == THREAD_NULL) { + assert(kqr->kqr_thread != THREAD_NULL); + thread_t servicer = kqr->kqr_thread; + + thread_reference(servicer); + thread_to_handoff = servicer; + } + + kqwl_req_unlock(kqwl); + + filt_wlunlock(kqwl); + + /* TODO: use continuation based blocking */ + + /* consume a refcount on thread_to_handoff, then thread_block() */ + wr = thread_handoff(thread_to_handoff); + thread_to_handoff = THREAD_NULL; + + filt_wllock(kqwl); + + /* clear waiting state (only one waiting thread - so no race) */ + assert(kn->kn_hook == current_thread()); + + if (qos_index) { + kqwl_req_lock(kqwl); + assert(kqr->kqr_dsync_waiters > 0); + if (--kqr->kqr_dsync_waiters == 0) { + assert(kqr->kqr_dsync_waiters_qos); + kqworkloop_update_threads_qos(kqwl, + KQWL_UTQ_SET_SYNC_WAITERS_QOS, 0); + } + kqwl_req_unlock(kqwl); + } + } + + kn->kn_hook = NULL; + + switch (wr) { + case THREAD_AWAKENED: + return 0; + case THREAD_INTERRUPTED: + return EINTR; + case THREAD_RESTART: + return ECANCELED; + default: + panic("filt_wlattach: unexpected wait result %d", wr); + return EINVAL; + } +} + +/* 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 == WL_OWNER_SUSPENDED) { + waitinfo->owner = STACKSHOT_WAITOWNER_SUSPENDED; + } else 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; + + return; +} + +/* + * Takes kqueue locked, returns locked, may drop in the middle and/or block for a while + */ +static int +filt_wlpost_attach(struct knote *kn, struct kevent_internal_s *kev) +{ + struct kqueue *kq = knote_get_kq(kn); + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + int error = 0; + + if (kev->fflags & NOTE_WL_SYNC_WAIT) { + if (kqlock2knoteuse(kq, kn, KNUSE_NONE)) { + filt_wllock(kqwl); + /* if the wake has already preposted, don't wait */ + if ((kn->kn_sfflags & NOTE_WL_SYNC_WAKE) == 0) + error = filt_wlwait(kqwl, kn, kev); + filt_wlunlock(kqwl); + knoteuse2kqlock(kq, kn, KNUSE_NONE); + } + } + return error; +} + +static void +filt_wldetach(__assert_only struct knote *kn) +{ + assert(knote_get_kq(kn)->kq_state & KQ_WORKLOOP); + + /* + * Thread requests have nothing to detach. + * Sync waiters should have been aborted out + * and drop their refs before we could drop/ + * detach their knotes. + */ + assert(kn->kn_hook == NULL); +} + +static int +filt_wlevent( + __unused struct knote *kn, + __unused long hint) +{ + panic("filt_wlevent"); + return 0; +} + +static int +filt_wlvalidate_kev_flags(struct knote *kn, struct kevent_internal_s *kev) +{ + int new_commands = kev->fflags & NOTE_WL_COMMANDS_MASK; + int sav_commands = kn->kn_sfflags & NOTE_WL_COMMANDS_MASK; + int error = 0; + + switch (new_commands) { + case NOTE_WL_THREAD_REQUEST: + /* thread requests can only update themselves */ + if (sav_commands != new_commands) + error = EINVAL; + break; + + case NOTE_WL_SYNC_WAIT: + if (kev->fflags & NOTE_WL_END_OWNERSHIP) error = EINVAL; + /* FALLTHROUGH */ + case NOTE_WL_SYNC_WAKE: + /* waits and wakes can update themselves or their counterparts */ + if (!(sav_commands & (NOTE_WL_SYNC_WAIT | NOTE_WL_SYNC_WAKE))) + error = EINVAL; + if (kev->fflags & NOTE_WL_UPDATE_QOS) + error = EINVAL; + if ((kev->flags & (EV_ENABLE | EV_DELETE)) == EV_ENABLE) + error = EINVAL; + if (kev->flags & EV_DELETE) { + /* + * Really this is not supported: there is absolutely no reason + * whatsoever to want to fail the drop of a NOTE_WL_SYNC_WAIT knote. + */ + if (kev->ext[EV_EXTIDX_WL_ADDR] && kev->ext[EV_EXTIDX_WL_MASK]) { + error = EINVAL; + } + } + break; + + default: + error = EINVAL; + } + if ((kev->flags & EV_DELETE) && (kev->fflags & NOTE_WL_DISCOVER_OWNER)) { + error = EINVAL; + } + return error; +} + +static int +filt_wltouch( + struct knote *kn, + struct kevent_internal_s *kev) +{ + struct kqueue *kq = knote_get_kq(kn); + int error = 0; + struct kqworkloop *kqwl; + + assert(kq->kq_state & KQ_WORKLOOP); + kqwl = (struct kqworkloop *)kq; + + error = filt_wlvalidate_kev_flags(kn, kev); + if (error) { + goto out; + } + + filt_wllock(kqwl); + + /* Make sure user and kernel are in agreement on important state */ + error = filt_wldebounce(kqwl, kev, 0); + if (error) { + error = filt_wlupdateowner(kqwl, kev, error, 0); + goto out_unlock; + } + + int new_command = kev->fflags & NOTE_WL_COMMANDS_MASK; + switch (new_command) { + case NOTE_WL_THREAD_REQUEST: + assert(kqwl->kqwl_request.kqr_qos_index != THREAD_QOS_UNSPECIFIED); + break; + + case NOTE_WL_SYNC_WAIT: + /* + * we need to allow waiting several times on the same knote because + * of EINTR. If it's already woken though, it won't block. + */ + break; + + case NOTE_WL_SYNC_WAKE: + if (kn->kn_sfflags & NOTE_WL_SYNC_WAKE) { + /* disallow waking the same knote twice */ + error = EALREADY; + goto out_unlock; + } + if (kn->kn_hook) { + thread_wakeup_thread((event_t)kn, (thread_t)kn->kn_hook); + } + break; + + default: + error = EINVAL; + goto out_unlock; + } + + /* + * 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; + + kq_index_t qos_index = THREAD_QOS_UNSPECIFIED; + + if (kev->fflags & NOTE_WL_UPDATE_QOS) { + qos_t qos = pthread_priority_canonicalize(kev->qos, FALSE); + + if (kn->kn_qos != qos) { + qos_index = qos_index_from_qos(kn, qos, FALSE); + if (qos_index == THREAD_QOS_UNSPECIFIED) { + error = ERANGE; + goto out_unlock; + } + kqlock(kq); + if (kn->kn_status & KN_QUEUED) { + knote_dequeue(kn); + knote_set_qos_index(kn, qos_index); + knote_enqueue(kn); + knote_wakeup(kn); + } else { + knote_set_qos_index(kn, qos_index); + } + kn->kn_qos = qos; + kqunlock(kq); + } + } + + error = filt_wlupdateowner(kqwl, kev, 0, qos_index); + if (error) { + goto out_unlock; + } + + if (new_command == NOTE_WL_SYNC_WAIT) { + /* if the wake has already preposted, don't wait */ + if ((kn->kn_sfflags & NOTE_WL_SYNC_WAKE) == 0) + error = filt_wlwait(kqwl, kn, kev); + } + +out_unlock: + filt_wlremember_last_update(kqwl, kn, kev, error); + filt_wlunlock(kqwl); +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; + } + /* Just touching the thread request successfully will fire it */ + return new_command == NOTE_WL_THREAD_REQUEST; +} + +static int +filt_wldrop_and_unlock( + struct knote *kn, + struct kevent_internal_s *kev) +{ + struct kqueue *kq = knote_get_kq(kn); + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + int error = 0, knoteuse_flags = KNUSE_NONE; + + kqlock_held(kq); + + assert(kev->flags & EV_DELETE); + assert(kq->kq_state & KQ_WORKLOOP); + + error = filt_wlvalidate_kev_flags(kn, kev); + if (error) { + goto out; + } + + if (kn->kn_sfflags & NOTE_WL_THREAD_REQUEST) { + knoteuse_flags |= KNUSE_BOOST; + } + + /* take a usecount to allow taking the filt_wllock */ + if (!kqlock2knoteuse(kq, kn, knoteuse_flags)) { + /* knote is being dropped already */ + error = EINPROGRESS; + goto out; + } + + filt_wllock(kqwl); + + /* + * Make sure user and kernel are in agreement on important state + * + * Userland will modify bits to cause this to fail for the touch / drop + * race case (when a drop for a thread request quiescing comes in late after + * the workloop has been woken up again). + */ + error = filt_wldebounce(kqwl, kev, 0); + + if (!knoteuse2kqlock(kq, kn, knoteuse_flags)) { + /* knote is no longer alive */ + error = EINPROGRESS; + goto out_unlock; + } + + if (!error && (kn->kn_sfflags & NOTE_WL_THREAD_REQUEST) && kn->kn_inuse) { + /* + * There is a concurrent drop or touch happening, we can't resolve this, + * userland has to redrive. + * + * The race we're worried about here is the following: + * + * f_touch | f_drop_and_unlock + * ------------------------+-------------------------------------------- + * | kqlock() + * | kqlock2knoteuse() + * | filt_wllock() + * | debounces successfully + * kqlock() | + * kqlock2knoteuse | + * filt_wllock() | + * | knoteuse2kqlock() + * | filt_wlunlock() + * | kqlock2knotedrop() + * debounces successfully | + * filt_wlunlock() | + * caller WAKES f_drop | + * | performs drop, but f_touch should have won + * + * So if the usecount is not 0 here, we need to wait for it to drop and + * redrive the whole logic (including looking up the knote again). + */ + filt_wlunlock(kqwl); + knoteusewait(kq, kn); + return ERESTART; + } + + /* + * If error is 0 this will set kqr_qos_index to THREAD_QOS_UNSPECIFIED + * + * If error is 0 or ESTALE this may drop ownership and cause a thread + * request redrive, however the kqlock is held which prevents f_process() to + * run until we did the drop for real. + */ + error = filt_wlupdateowner(kqwl, kev, error, 0); + if (error) { + goto out_unlock; + } + + 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; + if (kn->kn_hook) { + thread_wakeup_thread((event_t)kn, (thread_t)kn->kn_hook); + } + } + +out_unlock: + filt_wlremember_last_update(kqwl, kn, kev, error); + filt_wlunlock(kqwl); + +out: + if (error == 0) { + /* If nothing failed, do the regular knote drop. */ + if (kqlock2knotedrop(kq, kn)) { + knote_drop(kn, current_proc()); + } else { + error = EINPROGRESS; + } + } else { + kqunlock(kq); + } + if (error == ESTALE && (kev->fflags & NOTE_WL_IGNORE_ESTALE)) { + error = 0; + } + if (error == EINPROGRESS) { + /* + * filt_wlprocess() makes sure that no event can be delivered for + * NOTE_WL_THREAD_REQUEST knotes once a drop is happening, and + * NOTE_WL_SYNC_* knotes are never fired. + * + * It means that EINPROGRESS is about a state that userland cannot + * observe for this filter (an event being delivered concurrently from + * a drop), so silence the error. + */ + error = 0; + } + return error; +} + +static int +filt_wlprocess( + struct knote *kn, + __unused struct filt_process_s *data, + struct kevent_internal_s *kev) +{ + struct kqueue *kq = knote_get_kq(kn); + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + struct kqrequest *kqr = &kqwl->kqwl_request; + int rc = 0; + + assert(kq->kq_state & KQ_WORKLOOP); + + /* only thread requests should get here */ + assert(kn->kn_sfflags & NOTE_WL_THREAD_REQUEST); + if (kn->kn_sfflags & NOTE_WL_THREAD_REQUEST) { + filt_wllock(kqwl); + assert(kqr->kqr_qos_index != THREAD_QOS_UNSPECIFIED); + if (kqwl->kqwl_owner) { + /* + * 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(kq); + knote_activate(kn); kqunlock(kq); - goto errorout; + } else if (kqr->kqr_qos_index) { +#if DEBUG || DEVELOPMENT + 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) != 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 = 1; } + filt_wlunlock(kqwl); + } + return rc; +} + +#pragma mark kevent / knotes + +/* + * JMM - placeholder for not-yet-implemented filters + */ +static int +filt_badattach(__unused struct knote *kn, __unused struct kevent_internal_s *kev) +{ + kn->kn_flags |= EV_ERROR; + kn->kn_data = 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; + uint64_t kq_addr_offset; + + 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(&kq->kq_queue[i]); + } + for (i = 0; i < KQWQ_NQOS; i++) { + kqwq->kqwq_request[i].kqr_qos_index = i; + } + + lck_spin_init(&kqwq->kqwq_reqlock, kq_lck_grp, kq_lck_attr); + 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 */ + + kq = &kqwl->kqwl_kqueue; + for (i = 0; i < KQWL_NBUCKETS; i++) { + TAILQ_INIT(&kq->kq_queue[i]); + } + TAILQ_INIT(&kqwl->kqwl_request.kqr_suppressed); + + lck_spin_init(&kqwl->kqwl_reqlock, kq_lck_grp, kq_lck_attr); + lck_mtx_init(&kqwl->kqwl_statelock, kq_lck_grp, kq_lck_attr); + + policy = SYNC_POLICY_FIFO; + if (flags & KEVENT_FLAG_WORKLOOP_NO_WQ_THREAD) { + policy |= SYNC_POLICY_PREPOST; + kq->kq_state |= KQ_NO_WQ_THREAD; + } else { + 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(&kq->kq_queue[0]); + 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); + 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); + } + + kq_addr_offset = ((uintptr_t)kq - (uintptr_t)VM_MIN_KERNEL_AND_KEXT_ADDRESS); + /* Assert that the address can be pointer compacted for use with knote */ + assert(kq_addr_offset < (uint64_t)(1ull << KNOTE_KQ_BITSIZE)); + 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); + /* drop it ourselves or wait */ + if (kqlock2knotedrop(kq, kn)) { + knote_drop(kn, p); + } + 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); + /* drop it ourselves or wait */ + if (kqlock2knotedrop(kq, kn)) { + knote_drop(kn, p); + } + 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); +} + + +/* + * 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; + + 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)) { + assert((kq->kq_state & KQ_WORKLOOP) == 0); + kqlock(kq); + proc_fdunlock(p); + /* drop it ourselves or wait */ + if (kqlock2knotedrop(kq, kn)) { + knote_drop(kn, p); + } + proc_fdlock(p); + /* start over at beginning of list */ + kn = SLIST_FIRST(&fdp->fd_knlist[i]); + continue; + } + kn = SLIST_NEXT(kn, kn_link); + } + } + 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)) { + assert((kq->kq_state & KQ_WORKLOOP) == 0); + kqlock(kq); + knhash_unlock(p); + /* drop it ourselves or wait */ + if (kqlock2knotedrop(kq, kn)) { + knote_drop(kn, p); + } + 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; + struct kqrequest *kqr = &kqwl->kqwl_request; + thread_t cur_owner = kqwl->kqwl_owner; + + assert(TAILQ_EMPTY(&kqwl->kqwl_request.kqr_suppressed)); + if (filt_wlowner_is_valid(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 (kqr->kqr_dsync_owner_qos != THREAD_QOS_UNSPECIFIED) { + thread_drop_ipc_override(cur_owner); + kqr->kqr_dsync_owner_qos = THREAD_QOS_UNSPECIFIED; + } + + if (kqr->kqr_owner_override_is_sync) { + thread_drop_sync_ipc_override(cur_owner); + kqr->kqr_owner_override_is_sync = 0; + } + thread_ends_owning_workloop(cur_owner); + thread_deallocate(cur_owner); + kqwl->kqwl_owner = THREAD_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); + + if (kq->kq_state & KQ_WORKQ) { + struct kqworkq *kqwq = (struct kqworkq *)kq; + + lck_spin_destroy(&kqwq->kqwq_reqlock, kq_lck_grp); + zfree(kqworkq_zone, kqwq); + } else if (kq->kq_state & KQ_WORKLOOP) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + + assert(kqwl->kqwl_retains == 0); + lck_spin_destroy(&kqwl->kqwl_reqlock, kq_lck_grp); + lck_mtx_destroy(&kqwl->kqwl_statelock, kq_lck_grp); + zfree(kqworkloop_zone, kqwl); + } else { + struct kqfile *kqf = (struct kqfile *)kq; + + zfree(kqfile_zone, kqf); + } +} + +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(struct kqueue *kq, __assert_only int possibly_last) +{ + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + + if ((kq->kq_state & KQ_DYNAMIC) == 0) { + return 0; + } + + assert(kq->kq_state & KQ_WORKLOOP); /* for now */ + uint32_t refs = OSDecrementAtomic(&kqwl->kqwl_retains); + if (__improbable(refs == 0)) { + panic("kq(%p) over-release", 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, struct kqueue *kq) +{ + if (kq->kq_state & KQ_DYNAMIC) { + kqhash_lock(p); + if (kqueue_release(kq, KQUEUE_MIGHT_BE_LAST_REF)) { + kqueue_hash_remove(p, kq); + kqhash_unlock(p); + kqueue_dealloc(kq); + } else { + kqhash_unlock(p); + } + } +} + +static struct kqueue * +kevent_get_bound_kq(__assert_only struct proc *p, thread_t thread, + unsigned int kev_flags, unsigned int kq_flags) +{ + struct kqueue *kq; + struct uthread *ut = get_bsdthread_info(thread); + + assert(p == get_bsdthreadtask_info(thread)); + + if (!(ut->uu_kqueue_flags & kev_flags)) + return NULL; + + kq = ut->uu_kqueue_bound; + if (!kq) + return NULL; + + if (!(kq->kq_state & kq_flags)) + return NULL; + + return kq; +} + +static int +kevent_get_kq(struct proc *p, kqueue_id_t id, unsigned int flags, struct fileproc **fpp, int *fdp, struct kqueue **kqp) +{ + struct filedesc *descp = p->p_fd; + struct fileproc *fp = NULL; + struct kqueue *kq; + int fd = 0; + int error = 0; + + /* Was the workloop flag passed? Then it is for sure only a workloop */ + if (flags & KEVENT_FLAG_DYNAMIC_KQUEUE) { + assert(flags & KEVENT_FLAG_WORKLOOP); + if (id == (kqueue_id_t)-1 && + (flags & KEVENT_FLAG_KERNEL) && + (flags & KEVENT_FLAG_WORKLOOP)) { + + assert(is_workqueue_thread(current_thread())); + + /* + * 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. + * + * Until pthread kext avoids calling in to kevent_id_internal + * for threads whose fulfill is canceled, calling in unbound + * can't be fatal. + */ + kq = kevent_get_bound_kq(p, current_thread(), + KEVENT_FLAG_WORKLOOP, KQ_WORKLOOP); + if (kq) { + kqueue_retain(kq); + } else { + struct uthread *ut = get_bsdthread_info(current_thread()); + + /* If thread is unbound due to cancel, just return an error */ + if (ut->uu_kqueue_flags == KEVENT_FLAG_WORKLOOP_CANCELED) { + ut->uu_kqueue_flags = 0; + error = ECANCELED; + } else { + panic("Unbound thread called kevent_internal with id=-1" + " uu_kqueue_flags:0x%x, uu_kqueue_bound:%p", + ut->uu_kqueue_flags, ut->uu_kqueue_bound); + } + } + + *fpp = NULL; + *fdp = 0; + *kqp = kq; + return error; + } + + /* try shortcut on kq lookup for bound threads */ + kq = kevent_get_bound_kq(p, current_thread(), KEVENT_FLAG_WORKLOOP, KQ_WORKLOOP); + if (kq != NULL && ((struct kqworkloop *)kq)->kqwl_dynamicid == id) { + + if (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST) { + error = EEXIST; + kq = NULL; + goto out; + } + + /* retain a reference while working with this kq. */ + assert(kq->kq_state & KQ_DYNAMIC); + kqueue_retain(kq); + error = 0; + 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) { + error = ENOENT; + goto out; + } + + struct kqueue *alloc_kq; + alloc_kq = kqueue_alloc(p, flags); + if (alloc_kq) { + 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; + kqueue_hash_insert(p, id, kq); + kqhash_unlock(p); + } 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 { + error = ENOMEM; + goto out; + } + } else { + + if (flags & KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST) { + kqhash_unlock(p); + kq = NULL; + error = EEXIST; + goto out; + } + + /* 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; + 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); + assert(workloop_id); + + 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; + } + + 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 + 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 int +kevent_servicer_detach_preflight(thread_t thread, unsigned int flags, struct kqueue *kq) +{ + int error = 0; + struct kqworkloop *kqwl; + struct uthread *ut; + struct kqrequest *kqr; + + if (!(flags & KEVENT_FLAG_WORKLOOP) || !(kq->kq_state & KQ_WORKLOOP)) + return EINVAL; + + /* only kq created with KEVENT_FLAG_WORKLOOP_NO_WQ_THREAD from userspace can have attached threads */ + if (!(kq->kq_state & KQ_NO_WQ_THREAD)) + return EINVAL; + + /* allow detach only on not wq threads */ + if (is_workqueue_thread(thread)) + return EINVAL; + + /* check that the current thread is bound to the requested wq */ + ut = get_bsdthread_info(thread); + if (ut->uu_kqueue_bound != kq) + return EINVAL; + + kqwl = (struct kqworkloop *)kq; + kqwl_req_lock(kqwl); + kqr = &kqwl->kqwl_request; + + /* check that the wq is bound to the thread */ + if ((kqr->kqr_state & KQR_BOUND) == 0 || (kqr->kqr_thread != thread)) + error = EINVAL; + + kqwl_req_unlock(kqwl); + + return error; +} + +static void +kevent_servicer_detach_thread(struct proc *p, kqueue_id_t id, thread_t thread, + unsigned int flags, struct kqueue *kq) +{ + struct kqworkloop *kqwl; + struct uthread *ut; + + assert((flags & KEVENT_FLAG_WORKLOOP) && (kq->kq_state & KQ_WORKLOOP)); + + /* allow detach only on not wqthreads threads */ + assert(!is_workqueue_thread(thread)); + + /* only kq created with KEVENT_FLAG_WORKLOOP_NO_WQ_THREAD from userspace can have attached threads */ + assert(kq->kq_state & KQ_NO_WQ_THREAD); + + /* check that the current thread is bound to the requested kq */ + ut = get_bsdthread_info(thread); + assert(ut->uu_kqueue_bound == kq); + + kqwl = (struct kqworkloop *)kq; + + kqlock(kq); + + /* unbind the thread. + * unbind itself checks if still processing and ends it. + */ + kqworkloop_unbind_thread(kqwl, thread, flags); + + kqunlock(kq); + + kevent_put_kq(p, id, NULL, kq); + + return; +} + +static int +kevent_servicer_attach_thread(thread_t thread, unsigned int flags, struct kqueue *kq) +{ + int error = 0; + struct kqworkloop *kqwl; + struct uthread *ut; + struct kqrequest *kqr; + + if (!(flags & KEVENT_FLAG_WORKLOOP) || !(kq->kq_state & KQ_WORKLOOP)) + return EINVAL; + + /* only kq created with KEVENT_FLAG_WORKLOOP_NO_WQ_THREAD from userspace can have attached threads*/ + if (!(kq->kq_state & KQ_NO_WQ_THREAD)) + return EINVAL; + + /* allow attach only on not wqthreads */ + if (is_workqueue_thread(thread)) + return EINVAL; + + /* check that the thread is not already bound */ + ut = get_bsdthread_info(thread); + if (ut->uu_kqueue_bound != NULL) + return EINVAL; + + assert(ut->uu_kqueue_flags == 0); + + kqlock(kq); + kqwl = (struct kqworkloop *)kq; + kqwl_req_lock(kqwl); + kqr = &kqwl->kqwl_request; + + /* check that the kqueue is not already bound */ + if (kqr->kqr_state & (KQR_BOUND | KQR_THREQUESTED | KQR_DRAIN)) { + error = EINVAL; + goto out; + } + + assert(kqr->kqr_thread == NULL); + assert((kqr->kqr_state & KQR_PROCESSING) == 0); + + kqr->kqr_state |= KQR_THREQUESTED; + kqr->kqr_qos_index = THREAD_QOS_UNSPECIFIED; + kqr->kqr_override_index = THREAD_QOS_UNSPECIFIED; + kqr->kqr_dsync_owner_qos = THREAD_QOS_UNSPECIFIED; + kqr->kqr_owner_override_is_sync = 0; + + kqworkloop_bind_thread_impl(kqwl, thread, KEVENT_FLAG_WORKLOOP); + + /* get a ref on the wlkq on behalf of the attached thread */ + kqueue_retain(kq); + +out: + kqwl_req_unlock(kqwl); + kqunlock(kq); + + return error; +} + +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) +{ + struct _kevent *cont_args; + uthread_t ut; + struct kqueue *kq; + struct fileproc *fp = NULL; + int fd = 0; + struct kevent_internal_s kev; + int error, noutputs; + struct timeval atv; + user_size_t data_size; + user_size_t data_resid; + thread_t thread = current_thread(); + + /* 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; + + /* 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_SERVICER_ATTACH | KEVENT_FLAG_WORKLOOP_SERVICER_DETACH | + KEVENT_FLAG_DYNAMIC_KQ_MUST_EXIST | KEVENT_FLAG_DYNAMIC_KQ_MUST_NOT_EXIST | KEVENT_FLAG_WORKLOOP_NO_WQ_THREAD)) { + + /* 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; + + /* cannot attach and detach simultaneously*/ + if ((flags & KEVENT_FLAG_WORKLOOP_SERVICER_ATTACH) && (flags & KEVENT_FLAG_WORKLOOP_SERVICER_DETACH)) + return EINVAL; + + /* cannot ask for events and detach */ + if ((flags & KEVENT_FLAG_WORKLOOP_SERVICER_DETACH) && kevent_args_requesting_events(flags, nevents)) + 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, flags, &fp, &fd, &kq); + if (error) + return error; + + /* only bound threads can receive events on workloops */ + if ((flags & KEVENT_FLAG_WORKLOOP) && kevent_args_requesting_events(flags, nevents)) { + ut = (uthread_t)get_bsdthread_info(thread); + if (ut->uu_kqueue_bound != kq) { + error = EXDEV; + goto out; + } + + } + + /* attach the current thread if necessary */ + if (flags & KEVENT_FLAG_WORKLOOP_SERVICER_ATTACH) { + error = kevent_servicer_attach_thread(thread, flags, kq); + if (error) + goto out; + } + else { + /* before processing events and committing to the system call, return an error if the thread cannot be detached when requested */ + if (flags & KEVENT_FLAG_WORKLOOP_SERVICER_DETACH) { + error = kevent_servicer_detach_preflight(thread, flags, kq); + if (error) + goto out; + } + } + + if (id_out && kq && (flags & KEVENT_FLAG_WORKLOOP)) { + assert(kq->kq_state & KQ_WORKLOOP); + struct kqworkloop *kqwl; + kqwl = (struct kqworkloop *)kq; + *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; + + kevent_register(kq, &kev, p); + + if (nevents > 0 && + ((kev.flags & EV_ERROR) || (kev.flags & EV_RECEIPT))) { + if (kev.flags & EV_RECEIPT) { + 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) { + /* store the continuation/completion data in the uthread */ + ut = (uthread_t)get_bsdthread_info(thread); + cont_args = &ut->uu_kevent.ss_kevent; + cont_args->fp = fp; + cont_args->fd = fd; + cont_args->retval = retval; + cont_args->eventlist = ueventlist; + cont_args->eventcount = nevents; + cont_args->eventout = noutputs; + cont_args->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; + + 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); + } + } + + /* detach the current thread if necessary */ + if (flags & KEVENT_FLAG_WORKLOOP_SERVICER_DETACH) { + assert(fp == NULL); + kevent_servicer_detach_thread(p, id, thread, flags, kq); + } + +out: + 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); +} + +/* + * 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 + */ + +void +kevent_register(struct kqueue *kq, struct kevent_internal_s *kev, + __unused struct proc *ctxp) +{ + struct proc *p = kq->kq_p; + const struct filterops *fops; + struct knote *kn = NULL; + int result = 0; + int error = 0; + unsigned short kev_flags = kev->flags; + int knoteuse_flags = KNUSE_NONE; + + 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); + + if (kn == NULL) { + if (kev->flags & EV_ADD) { + 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; + knote_set_kq(kn, kq); + kqueue_retain(kq); /* retain a kq ref */ + kn->kn_filtid = ~kev->filter; + kn->kn_inuse = 1; /* for f_attach() */ + 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; + + /* + * 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; + + /* invoke pthread kext to convert kevent qos to thread qos */ + knote_canonicalize_kevent_qos(kn); + knote_set_qos_index(kn, qos_index_from_qos(kn, kn->kn_qos, FALSE)); + + /* before anyone can find it */ + if (kev->flags & EV_DISABLE) { + /* + * do this before anyone can find it, + * this can't call knote_disable() because it expects having + * the kqlock held + */ + kn->kn_status |= KN_DISABLED; + } + + /* Add the knote for lookup thru the fd table */ + error = kq_add_knote(kq, kn, kev, p, &knoteuse_flags); + 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) { + error = 0; + goto restart; + } + goto out; + } + + /* fp reference count now applies to knote */ + /* rwlock boost is now held */ + + /* call filter attach routine */ + result = fops->f_attach(kn, kev); + + /* + * Trade knote use count for kq lock. + * Cannot be dropped because we held + * KN_ATTACHING throughout. + */ + knoteuse2kqlock(kq, kn, KNUSE_STEAL_DROP | knoteuse_flags); + + if (kn->kn_flags & EV_ERROR) { + /* + * Failed to attach correctly, so drop. + * All other possible users/droppers + * have deferred to us. Save the error + * to return to our caller. + */ + kn->kn_status &= ~KN_ATTACHED; + kn->kn_status |= KN_DROPPING; + error = kn->kn_data; + kqunlock(kq); + knote_drop(kn, p); + goto out; + } + + /* end "attaching" phase - now just attached */ + kn->kn_status &= ~KN_ATTACHING; + + if (kn->kn_status & KN_DROPPING) { + /* + * Attach succeeded, but someone else + * deferred their drop - now we have + * to do it for them. + */ + kqunlock(kq); + knote_drop(kn, p); + goto out; + } + + /* Mark the thread request overcommit - if appropos */ + knote_set_qos_overcommit(kn); + + /* + * If the attach routine indicated that an + * event is already fired, activate the knote. + */ + if (result) + knote_activate(kn); + + if (knote_fops(kn)->f_post_attach) { + error = knote_fops(kn)->f_post_attach(kn, kev); + if (error) { + kqunlock(kq); + goto out; + } + } + + } else { + if ((kev_flags & (EV_ADD | EV_DELETE)) == (EV_ADD | 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 { + /* existing knote: kqueue lock already taken by kq_find_knote_and_kq_lock */ + + if ((kn->kn_status & (KN_DROPPING | KN_ATTACHING)) != 0) { + /* + * The knote is not in a stable state, wait for that + * transition to complete and then redrive the lookup. + */ + knoteusewait(kq, kn); + goto restart; + } + + if (kev->flags & EV_DELETE) { + + /* + * If attempting to delete a disabled dispatch2 knote, + * we must wait for the knote to be re-enabled (unless + * it is being re-enabled atomically here). + */ + if ((kev->flags & EV_ENABLE) == 0 && + (kn->kn_status & (KN_DISPATCH2 | KN_DISABLED)) == + (KN_DISPATCH2 | KN_DISABLED)) { + kn->kn_status |= KN_DEFERDELETE; + kqunlock(kq); + error = EINPROGRESS; + } else if (knote_fops(kn)->f_drop_and_unlock) { + /* + * The filter has requested to handle EV_DELETE events + * + * ERESTART means the kevent has to be re-evaluated + */ + error = knote_fops(kn)->f_drop_and_unlock(kn, kev); + if (error == ERESTART) { + error = 0; + goto restart; + } + } else if (kqlock2knotedrop(kq, kn)) { + /* standard/default EV_DELETE path */ + knote_drop(kn, p); + } else { + /* + * The kqueue is unlocked, it's not being + * dropped, and kqlock2knotedrop returned 0: + * this means that someone stole the drop of + * the knote from us. + */ + error = EINPROGRESS; + } + goto out; + } + + /* + * If we are re-enabling a deferred-delete knote, + * just enable it now and avoid calling the + * filter touch routine (it has delivered its + * last event already). + */ + if ((kev->flags & EV_ENABLE) && + (kn->kn_status & KN_DEFERDELETE)) { + assert(kn->kn_status & KN_DISABLED); + knote_activate(kn); + knote_enable(kn); + kqunlock(kq); + goto out; + } + + /* + * If we are disabling, do it before unlocking and + * calling the touch routine (so no processing can + * see the new kevent state before the disable is + * applied). + */ + if (kev->flags & EV_DISABLE) + knote_disable(kn); + + /* + * Convert the kqlock to a use reference on the + * knote so we can call the filter touch routine. + */ + if (knoteuse_needs_boost(kn, kev)) { + knoteuse_flags |= KNUSE_BOOST; + } + if (kqlock2knoteuse(kq, kn, knoteuse_flags)) { + /* + * Call touch routine to notify filter of changes + * in filter values (and to re-determine if any + * events are fired). + */ + result = knote_fops(kn)->f_touch(kn, kev); + + /* Get the kq lock back (don't defer droppers). */ + if (!knoteuse2kqlock(kq, kn, knoteuse_flags)) { + kqunlock(kq); + goto out; + } + + /* Handle errors during touch routine */ + if (kev->flags & EV_ERROR) { + error = kev->data; + kqunlock(kq); + goto out; + } + + /* Activate it if the touch routine said to */ + if (result) + knote_activate(kn); + } + + /* Enable the knote if called for */ + if (kev->flags & EV_ENABLE) + knote_enable(kn); + + } + + /* still have kqlock held and knote is valid */ + kqunlock(kq); + +out: + /* output local errors through the kevent */ + if (error) { + kev->flags |= EV_ERROR; + kev->data = error; + } +} + + +/* + * knote_process - process a triggered event + * + * Validate that it is really still a triggered event + * by calling the filter routines (if necessary). Hold + * a use reference on the knote to avoid it being detached. + * + * If it is still considered triggered, 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 proc *p) +{ + struct kevent_internal_s kev; + struct kqueue *kq = knote_get_kq(kn); + int result = 0; + int error = 0; + + 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); + } + + /* + * 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. + */ + if (kn->kn_status & (KN_DEFERDELETE | KN_VANISHED)) { + /* create fake event */ + kev.filter = kn->kn_filter; + kev.ident = kn->kn_id; + kev.qos = kn->kn_qos; + kev.flags = (kn->kn_status & KN_DEFERDELETE) ? + EV_DELETE : EV_VANISHED; + kev.flags |= (EV_DISPATCH2 | EV_ONESHOT); + kev.udata = kn->kn_udata; + result = 1; + + knote_suppress(kn); + } else { + int flags = KNUSE_NONE; + /* deactivate - so new activations indicate a wakeup */ + knote_deactivate(kn); + + /* suppress knotes to avoid returning the same event multiple times in a single call. */ + knote_suppress(kn); + + if (knoteuse_needs_boost(kn, NULL)) { + flags |= KNUSE_BOOST; + } + /* convert lock to a knote use reference */ + if (!kqlock2knoteuse(kq, kn, flags)) + panic("dropping knote found on queue\n"); + + /* call out to the filter to process with just a ref */ + result = knote_fops(kn)->f_process(kn, process_data, &kev); + if (result) flags |= KNUSE_STEAL_DROP; + + /* + * convert our reference back to a lock. accept drop + * responsibility from others if we've committed to + * delivering event data. + */ + if (!knoteuse2kqlock(kq, kn, flags)) { + /* knote dropped */ + kn = NULL; + } + } + + if (kn != NULL) { + /* + * 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. + * stolendrop:We took responsibility for someone else's drop attempt. + * treat this just like one-shot and prepare to turn it back + * into a deferred delete if required. + * 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 == 0) + return (EJUSTRETURN); + + if ((kev.flags & EV_ONESHOT) || (kn->kn_status & KN_STOLENDROP)) { + 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); + + /* if we took over another's drop clear those flags here */ + if (kn->kn_status & KN_STOLENDROP) { + assert(kn->kn_status & KN_DROPPING); + /* + * the knote will be dropped when the + * deferred deletion occurs + */ + kn->kn_status &= ~(KN_DROPPING|KN_STOLENDROP); + } + } else if (kn->kn_status & KN_STOLENDROP) { + /* We now own the drop of the knote. */ + assert(kn->kn_status & KN_DROPPING); + knote_unsuppress(kn); + kqunlock(kq); + knote_drop(kn, p); + kqlock(kq); + } else if (kqlock2knotedrop(kq, kn)) { + /* just EV_ONESHOT, _not_ DISPATCH2 */ + knote_drop(kn, p); + kqlock(kq); + } + } 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 (result) { + kqunlock(kq); + error = (callback)(kq, &kev, callback_data); + kqlock(kq); + } + return (error); +} + + +/* + * Return 0 to indicate that processing should proceed, + * -1 if there is nothing to process. + * + * Called with kqueue locked and returns the same way, + * but may drop lock temporarily. + */ +static int +kqworkq_begin_processing(struct kqworkq *kqwq, kq_index_t qos_index, int flags) +{ + struct kqrequest *kqr; + thread_t self = current_thread(); + __assert_only struct uthread *ut = get_bsdthread_info(self); + + assert(kqwq->kqwq_state & KQ_WORKQ); + assert(qos_index < KQWQ_NQOS); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_PROCESS_BEGIN) | DBG_FUNC_START, + flags, qos_index); + + kqwq_req_lock(kqwq); + + kqr = kqworkq_get_request(kqwq, qos_index); + + /* manager skips buckets that haven't asked for its help */ + if (flags & KEVENT_FLAG_WORKQ_MANAGER) { + + /* If nothing for manager to do, just return */ + if ((kqr->kqr_state & KQWQ_THMANAGER) == 0) { + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_PROCESS_BEGIN) | DBG_FUNC_END, + 0, kqr->kqr_state); + kqwq_req_unlock(kqwq); + return -1; + } + /* bind manager thread from this time on */ + kqworkq_bind_thread_impl(kqwq, qos_index, self, flags); + + } else { + /* We should already be bound to this kqueue */ + assert(kqr->kqr_state & KQR_BOUND); + assert(kqr->kqr_thread == self); + assert(ut->uu_kqueue_bound == (struct kqueue *)kqwq); + assert(ut->uu_kqueue_qos_index == qos_index); + assert((ut->uu_kqueue_flags & flags) == ut->uu_kqueue_flags); + } + + /* + * we should have been requested to be here + * and nobody else should still be processing + */ + assert(kqr->kqr_state & KQR_WAKEUP); + assert(kqr->kqr_state & KQR_THREQUESTED); + assert((kqr->kqr_state & KQR_PROCESSING) == 0); + + /* reset wakeup trigger to catch new events after we start processing */ + kqr->kqr_state &= ~KQR_WAKEUP; + + /* convert to processing mode */ + kqr->kqr_state |= KQR_PROCESSING; + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_PROCESS_BEGIN) | DBG_FUNC_END, + kqr_thread_id(kqr), kqr->kqr_state); + + kqwq_req_unlock(kqwq); + return 0; +} + +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 void +kqworkloop_acknowledge_events(struct kqworkloop *kqwl, boolean_t clear_ipc_override) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; + 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) { + /* + * When called from unbind, clear the sync ipc override on the knote + * for events which are delivered. + */ + if (clear_ipc_override) { + knote_adjust_sync_qos(kn, THREAD_QOS_UNSPECIFIED, FALSE); + } + continue; + } + knote_unsuppress(kn); + } +} + +static int +kqworkloop_begin_processing(struct kqworkloop *kqwl, + __assert_only unsigned int flags) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; + struct kqueue *kq = &kqwl->kqwl_kqueue; + + kqlock_held(kq); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_BEGIN) | DBG_FUNC_START, + kqwl->kqwl_dynamicid, flags, 0); + + kqwl_req_lock(kqwl); + + /* nobody else should still be processing */ + assert((kqr->kqr_state & KQR_PROCESSING) == 0); + assert((kq->kq_state & KQ_PROCESSING) == 0); + + kqr->kqr_state |= KQR_PROCESSING | KQR_R2K_NOTIF_ARMED; + kq->kq_state |= KQ_PROCESSING; + + kqwl_req_unlock(kqwl); + + kqworkloop_acknowledge_events(kqwl, FALSE); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_BEGIN) | DBG_FUNC_END, + kqwl->kqwl_dynamicid, flags, 0); + + return 0; +} + +/* + * 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 +kqueue_begin_processing(struct kqueue *kq, kq_index_t qos_index, unsigned int flags) +{ + struct kqtailq *suppressq; + + kqlock_held(kq); + + if (kq->kq_state & KQ_WORKQ) { + return kqworkq_begin_processing((struct kqworkq *)kq, qos_index, flags); + } else if (kq->kq_state & KQ_WORKLOOP) { + return kqworkloop_begin_processing((struct kqworkloop*)kq, flags); + } + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_BEGIN) | DBG_FUNC_START, + VM_KERNEL_UNSLIDE_OR_PERM(kq), flags); + + assert(qos_index == QOS_INDEX_KQFILE); + + /* 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, qos_index); + waitq_assert_wait64((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(suppressq), + THREAD_UNINT, 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)) { + 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; +} + +/* + * kqworkq_end_processing - Complete the processing of a workq kqueue + * + * 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) + * + * Called with kqueue lock held. + */ +static void +kqworkq_end_processing(struct kqworkq *kqwq, kq_index_t qos_index, int flags) +{ +#pragma unused(flags) + + struct kqueue *kq = &kqwq->kqwq_kqueue; + struct kqtailq *suppressq = kqueue_get_suppressed_queue(kq, qos_index); + + thread_t self = current_thread(); + struct uthread *ut = get_bsdthread_info(self); + struct knote *kn; + struct kqrequest *kqr; + thread_t thread; + + assert(kqwq->kqwq_state & KQ_WORKQ); + assert(qos_index < KQWQ_NQOS); + + /* Are we really bound to this kqueue? */ + if (ut->uu_kqueue_bound != kq) { + assert(ut->uu_kqueue_bound == kq); + return; + } + + kqr = kqworkq_get_request(kqwq, qos_index); + + kqwq_req_lock(kqwq); + + /* Do we claim to be manager? */ + if (flags & KEVENT_FLAG_WORKQ_MANAGER) { + + /* bail if not bound that way */ + if (ut->uu_kqueue_qos_index != KQWQ_QOS_MANAGER || + (ut->uu_kqueue_flags & KEVENT_FLAG_WORKQ_MANAGER) == 0) { + assert(ut->uu_kqueue_qos_index == KQWQ_QOS_MANAGER); + assert(ut->uu_kqueue_flags & KEVENT_FLAG_WORKQ_MANAGER); + kqwq_req_unlock(kqwq); + return; + } + + /* bail if this request wasn't already getting manager help */ + if ((kqr->kqr_state & KQWQ_THMANAGER) == 0 || + (kqr->kqr_state & KQR_PROCESSING) == 0) { + kqwq_req_unlock(kqwq); + return; + } + } else { + if (ut->uu_kqueue_qos_index != qos_index || + (ut->uu_kqueue_flags & KEVENT_FLAG_WORKQ_MANAGER)) { + assert(ut->uu_kqueue_qos_index == qos_index); + assert((ut->uu_kqueue_flags & KEVENT_FLAG_WORKQ_MANAGER) == 0); + kqwq_req_unlock(kqwq); + return; + } + } + + assert(kqr->kqr_state & KQR_BOUND); + thread = kqr->kqr_thread; + assert(thread == self); + + assert(kqr->kqr_state & KQR_PROCESSING); + + /* If we didn't drain the whole queue, re-mark a wakeup being needed */ + if (!kqueue_queue_empty(kq, qos_index)) + kqr->kqr_state |= KQR_WAKEUP; + + kqwq_req_unlock(kqwq); + + /* + * 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(suppressq)) != NULL) { + assert(kn->kn_status & KN_SUPPRESSED); + knote_unsuppress(kn); + } + + kqwq_req_lock(kqwq); + + /* Indicate that we are done processing this request */ + kqr->kqr_state &= ~KQR_PROCESSING; + + /* + * Drop our association with this one request and its + * override on us. + */ + kqworkq_unbind_thread(kqwq, qos_index, thread, flags); + + /* + * 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) { + if (kqueue_queue_empty(kq, qos_index)) { + kqr->kqr_state &= ~KQR_WAKEUP; + } else { + kqworkq_request_thread(kqwq, qos_index); + } + } + kqwq_req_unlock(kqwq); +} + +static void +kqworkloop_end_processing(struct kqworkloop *kqwl, int nevents, + unsigned int flags) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; + struct kqueue *kq = &kqwl->kqwl_kqueue; + + kqlock_held(kq); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_END) | DBG_FUNC_START, + kqwl->kqwl_dynamicid, flags, 0); + + if ((kq->kq_state & KQ_NO_WQ_THREAD) && nevents == 0 && + (flags & KEVENT_FLAG_IMMEDIATE) == 0) { + /* + * We may soon block, but have returned no + * kevents that need to be kept supressed for overriding purposes. + * + * It is hence safe to acknowledge events and unsuppress everything, so + * that if we block we can observe all events firing. + */ + kqworkloop_acknowledge_events(kqwl, TRUE); + } + + kqwl_req_lock(kqwl); + + assert(kqr->kqr_state & KQR_PROCESSING); + assert(kq->kq_state & KQ_PROCESSING); + + kq->kq_state &= ~KQ_PROCESSING; + kqr->kqr_state &= ~KQR_PROCESSING; + kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_RECOMPUTE_WAKEUP_QOS, 0); + + kqwl_req_unlock(kqwl); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_PROCESS_END) | DBG_FUNC_END, + kqwl->kqwl_dynamicid, flags, 0); +} + +/* + * Called with kqueue lock held. + */ +static void +kqueue_end_processing(struct kqueue *kq, kq_index_t qos_index, + int nevents, unsigned int flags) +{ + struct knote *kn; + struct kqtailq *suppressq; + int procwait; + + kqlock_held(kq); + + assert((kq->kq_state & KQ_WORKQ) == 0); + + if (kq->kq_state & KQ_WORKLOOP) { + return kqworkloop_end_processing((struct kqworkloop *)kq, nevents, flags); + } + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQ_PROCESS_END), + VM_KERNEL_UNSLIDE_OR_PERM(kq), flags); + + assert(qos_index == QOS_INDEX_KQFILE); + + /* + * Return suppressed knotes to their original state. + */ + suppressq = kqueue_get_suppressed_queue(kq, qos_index); + 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); + } +} + +/* + * kqwq_internal_bind - bind thread to processing workq kqueue + * + * Determines if the provided thread will be responsible for + * servicing the particular QoS class index specified in the + * parameters. Once the binding is done, any overrides that may + * be associated with the cooresponding events can be applied. + * + * This should be called as soon as the thread identity is known, + * preferably while still at high priority during creation. + * + * - caller holds a reference on the process (and workq kq) + * - the thread MUST call kevent_qos_internal after being bound + * or the bucket of events may never be delivered. + * - Nothing locked + * (unless this is a synchronous bind, then the request is locked) + */ +static int +kqworkq_internal_bind( + struct proc *p, + kq_index_t qos_index, + thread_t thread, + unsigned int flags) +{ + struct kqueue *kq; + struct kqworkq *kqwq; + struct kqrequest *kqr; + struct uthread *ut = get_bsdthread_info(thread); + + /* If no process workq, can't be our thread. */ + kq = p->p_fd->fd_wqkqueue; + + if (kq == NULL) + return 0; + + assert(kq->kq_state & KQ_WORKQ); + kqwq = (struct kqworkq *)kq; + + /* + * No need to bind the manager thread to any specific + * bucket, but still claim the thread. + */ + if (qos_index == KQWQ_QOS_MANAGER) { + assert(ut->uu_kqueue_bound == NULL); + assert(flags & KEVENT_FLAG_WORKQ_MANAGER); + ut->uu_kqueue_bound = kq; + ut->uu_kqueue_qos_index = qos_index; + ut->uu_kqueue_flags = flags; + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_BIND), + thread_tid(thread), flags, qos_index); + + return 1; + } + + /* + * If this is a synchronous bind callback, the request + * lock is already held, so just do the bind. + */ + if (flags & KEVENT_FLAG_SYNCHRONOUS_BIND) { + kqwq_req_held(kqwq); + /* strip out synchronout bind flag */ + flags &= ~KEVENT_FLAG_SYNCHRONOUS_BIND; + kqworkq_bind_thread_impl(kqwq, qos_index, thread, flags); + return 1; + } + + /* + * check the request that corresponds to our qos_index + * to see if there is an outstanding request. + */ + kqr = kqworkq_get_request(kqwq, qos_index); + assert(kqr->kqr_qos_index == qos_index); + kqwq_req_lock(kqwq); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_BIND), + thread_tid(thread), flags, qos_index, kqr->kqr_state); + + if ((kqr->kqr_state & KQR_THREQUESTED) && + (kqr->kqr_state & KQR_PROCESSING) == 0) { + + if ((kqr->kqr_state & KQR_BOUND) && + thread == kqr->kqr_thread) { + /* duplicate bind - claim the thread */ + assert(ut->uu_kqueue_bound == kq); + assert(ut->uu_kqueue_qos_index == qos_index); + kqwq_req_unlock(kqwq); + return 1; + } + if ((kqr->kqr_state & (KQR_BOUND | KQWQ_THMANAGER)) == 0) { + /* ours to bind to */ + kqworkq_bind_thread_impl(kqwq, qos_index, thread, flags); + kqwq_req_unlock(kqwq); + return 1; + } + } + kqwq_req_unlock(kqwq); + return 0; +} + +static void +kqworkloop_bind_thread_impl(struct kqworkloop *kqwl, + thread_t thread, + __assert_only unsigned int flags) +{ + assert(flags & KEVENT_FLAG_WORKLOOP); + + /* the request object must be locked */ + kqwl_req_held(kqwl); + + struct kqrequest *kqr = &kqwl->kqwl_request; + struct uthread *ut = get_bsdthread_info(thread); + boolean_t ipc_override_is_sync; + kq_index_t qos_index = kqworkloop_combined_qos(kqwl, &ipc_override_is_sync); + + /* nobody else bound so finally bind (as a workloop) */ + assert(kqr->kqr_state & KQR_THREQUESTED); + assert((kqr->kqr_state & (KQR_BOUND | KQR_PROCESSING)) == 0); + assert(thread != kqwl->kqwl_owner); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_BIND), + kqwl->kqwl_dynamicid, (uintptr_t)thread_tid(thread), + qos_index, + (uintptr_t)(((uintptr_t)kqr->kqr_override_index << 16) | + (((uintptr_t)kqr->kqr_state) << 8) | + ((uintptr_t)ipc_override_is_sync))); + + kqr->kqr_state |= KQR_BOUND | KQR_R2K_NOTIF_ARMED; + kqr->kqr_thread = thread; + + /* bind the workloop to the uthread */ + ut->uu_kqueue_bound = (struct kqueue *)kqwl; + ut->uu_kqueue_flags = flags; + ut->uu_kqueue_qos_index = qos_index; + assert(ut->uu_kqueue_override_is_sync == 0); + ut->uu_kqueue_override_is_sync = ipc_override_is_sync; + if (qos_index) { + thread_add_ipc_override(thread, qos_index); + } + if (ipc_override_is_sync) { + thread_add_sync_ipc_override(thread); + } +} + +/* + * workloop_fulfill_threadreq - bind thread to processing workloop + * + * 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. + * + * If WORKLOOP_FULFILL_THREADREQ_SYNC is specified, the callback + * within the context of the pthread_functions->workq_threadreq + * callout. In this case, the request structure is already locked. + */ +int +workloop_fulfill_threadreq(struct proc *p, + workq_threadreq_t req, + thread_t thread, + int flags) +{ + int sync = (flags & WORKLOOP_FULFILL_THREADREQ_SYNC); + int cancel = (flags & WORKLOOP_FULFILL_THREADREQ_CANCEL); + struct kqrequest *kqr; + struct kqworkloop *kqwl; + + kqwl = (struct kqworkloop *)((uintptr_t)req - + offsetof(struct kqworkloop, kqwl_request) - + offsetof(struct kqrequest, kqr_req)); + kqr = &kqwl->kqwl_request; + + /* validate we're looking at something valid */ + if (kqwl->kqwl_p != p || + (kqwl->kqwl_state & KQ_WORKLOOP) == 0) { + assert(kqwl->kqwl_p == p); + assert(kqwl->kqwl_state & KQ_WORKLOOP); + return EINVAL; + } + + if (!sync) + kqwl_req_lock(kqwl); + + /* Should be a pending request */ + if ((kqr->kqr_state & KQR_BOUND) || + (kqr->kqr_state & KQR_THREQUESTED) == 0) { + + assert((kqr->kqr_state & KQR_BOUND) == 0); + assert(kqr->kqr_state & KQR_THREQUESTED); + if (!sync) + kqwl_req_unlock(kqwl); + return EINPROGRESS; + } + + assert((kqr->kqr_state & KQR_DRAIN) == 0); + + /* + * Is it a cancel indication from pthread. + * If so, we must be exiting/exec'ing. Forget + * our pending request. + */ + if (cancel) { + kqr->kqr_state &= ~KQR_THREQUESTED; + kqr->kqr_state |= KQR_DRAIN; + } else { + /* do the actual bind? */ + kqworkloop_bind_thread_impl(kqwl, thread, KEVENT_FLAG_WORKLOOP); + } + + if (!sync) + kqwl_req_unlock(kqwl); + + if (cancel) + kqueue_release_last(p, &kqwl->kqwl_kqueue); /* may dealloc kq */ + + return 0; +} + + +/* + * kevent_qos_internal_bind - bind thread to processing kqueue + * + * Indicates that the provided thread will be responsible for + * servicing the particular QoS class index specified in the + * parameters. Once the binding is done, any overrides that may + * be associated with the cooresponding events can be applied. + * + * This should be called as soon as the thread identity is known, + * preferably while still at high priority during creation. + * + * - caller holds a reference on the kqueue. + * - the thread MUST call kevent_qos_internal after being bound + * or the bucket of events may never be delivered. + * - Nothing locked (may take mutex or block). + */ + +int +kevent_qos_internal_bind( + struct proc *p, + int qos_class, + thread_t thread, + unsigned int flags) +{ + kq_index_t qos_index; + + assert(flags & KEVENT_FLAG_WORKQ); + + if (thread == THREAD_NULL || (flags & KEVENT_FLAG_WORKQ) == 0) { + return EINVAL; + } + + /* get the qos index we're going to service */ + qos_index = qos_index_for_servicer(qos_class, thread, flags); + + if (kqworkq_internal_bind(p, qos_index, thread, flags)) + return 0; + + return EINPROGRESS; +} + + +static void +kqworkloop_internal_unbind( + struct proc *p, + thread_t thread, + unsigned int flags) +{ + struct kqueue *kq; + struct kqworkloop *kqwl; + struct uthread *ut = get_bsdthread_info(thread); + + assert(ut->uu_kqueue_bound != NULL); + kq = ut->uu_kqueue_bound; + assert(kq->kq_state & KQ_WORKLOOP); + kqwl = (struct kqworkloop *)kq; + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_UNBIND), + kqwl->kqwl_dynamicid, (uintptr_t)thread_tid(thread), + flags, 0); + + if (!(kq->kq_state & KQ_NO_WQ_THREAD)) { + assert(is_workqueue_thread(thread)); + + kqlock(kq); + kqworkloop_unbind_thread(kqwl, thread, flags); + kqunlock(kq); + + /* If last reference, dealloc the workloop kq */ + kqueue_release_last(p, kq); + } else { + assert(!is_workqueue_thread(thread)); + kevent_servicer_detach_thread(p, kqwl->kqwl_dynamicid, thread, flags, kq); + } +} + +static void +kqworkq_internal_unbind( + struct proc *p, + kq_index_t qos_index, + thread_t thread, + unsigned int flags) +{ + struct kqueue *kq; + struct kqworkq *kqwq; + struct uthread *ut; + kq_index_t end_index; + + assert(thread == current_thread()); + ut = get_bsdthread_info(thread); + + kq = p->p_fd->fd_wqkqueue; + assert(kq->kq_state & KQ_WORKQ); + assert(ut->uu_kqueue_bound == kq); + + kqwq = (struct kqworkq *)kq; + + /* end servicing any requests we might own */ + end_index = (qos_index == KQWQ_QOS_MANAGER) ? + 0 : qos_index; + kqlock(kq); + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_UNBIND), + (uintptr_t)thread_tid(thread), flags, qos_index); + + do { + kqworkq_end_processing(kqwq, qos_index, flags); + } while (qos_index-- > end_index); + + ut->uu_kqueue_bound = NULL; + ut->uu_kqueue_qos_index = 0; + ut->uu_kqueue_flags = 0; + + kqunlock(kq); +} + +/* + * kevent_qos_internal_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. + * thread is the current thread. + */ + +int +kevent_qos_internal_unbind( + struct proc *p, + int qos_class, + thread_t thread, + unsigned int flags) +{ +#pragma unused(qos_class) + + struct uthread *ut; + struct kqueue *kq; + unsigned int bound_flags; + bool check_flags; + + ut = get_bsdthread_info(thread); + if (ut->uu_kqueue_bound == NULL) { + /* early out if we are already unbound */ + assert(ut->uu_kqueue_flags == 0); + assert(ut->uu_kqueue_qos_index == 0); + assert(ut->uu_kqueue_override_is_sync == 0); + return EALREADY; + } + + assert(flags & (KEVENT_FLAG_WORKQ | KEVENT_FLAG_WORKLOOP)); + assert(thread == current_thread()); + + check_flags = flags & KEVENT_FLAG_UNBIND_CHECK_FLAGS; + + /* Get the kqueue we started with */ + kq = ut->uu_kqueue_bound; + assert(kq != NULL); + assert(kq->kq_state & (KQ_WORKQ | KQ_WORKLOOP)); + + /* get flags and QoS parameters we started with */ + bound_flags = ut->uu_kqueue_flags; + + /* Unbind from the class of workq */ + if (kq->kq_state & KQ_WORKQ) { + if (check_flags && !(flags & KEVENT_FLAG_WORKQ)) { + return EINVAL; + } + + kqworkq_internal_unbind(p, ut->uu_kqueue_qos_index, thread, bound_flags); + } else { + if (check_flags && !(flags & KEVENT_FLAG_WORKLOOP)) { + return EINVAL; + } + + kqworkloop_internal_unbind(p, thread, bound_flags); + } + + return 0; +} + +/* + * kqueue_process - process the triggered events in a kqueue + * + * Walk the queued knotes and validate that they are + * really still triggered events by calling the filter + * routines (if necessary). Hold a use reference on + * the knote to avoid it being detached. For each event + * that is still considered triggered, invoke the + * callback routine provided. + * + * caller holds a reference on the kqueue. + * kqueue locked on entry and exit - but may be dropped + * kqueue list locked (held for duration of call) + */ + +static int +kqueue_process(struct kqueue *kq, + kevent_callback_t callback, + void *callback_data, + struct filt_process_s *process_data, + int *countp, + struct proc *p) +{ + unsigned int flags = process_data ? process_data->fp_flags : 0; + struct uthread *ut = get_bsdthread_info(current_thread()); + kq_index_t start_index, end_index, i; + struct knote *kn; + int nevents = 0; + int error = 0; + + /* + * Based on the mode of the kqueue and the bound QoS of the servicer, + * determine the range of thread requests that need checking + */ + if (kq->kq_state & KQ_WORKQ) { + if (flags & KEVENT_FLAG_WORKQ_MANAGER) { + start_index = KQWQ_QOS_MANAGER; + } else if (ut->uu_kqueue_bound != kq) { + return EJUSTRETURN; + } else { + start_index = ut->uu_kqueue_qos_index; + } + + /* manager services every request in a workq kqueue */ + assert(start_index > 0 && start_index <= KQWQ_QOS_MANAGER); + end_index = (start_index == KQWQ_QOS_MANAGER) ? 0 : start_index; + + } else if (kq->kq_state & KQ_WORKLOOP) { + if (ut->uu_kqueue_bound != kq) + return EJUSTRETURN; + + /* + * Single request servicing + * we want to deliver all events, regardless of the QOS + */ + start_index = end_index = THREAD_QOS_UNSPECIFIED; + } else { + start_index = end_index = QOS_INDEX_KQFILE; + } + + i = start_index; + + do { + if (kqueue_begin_processing(kq, i, flags) == -1) { + *countp = 0; + /* Nothing to process */ + continue; + } + + /* + * 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. + */ + error = 0; + + struct kqtailq *base_queue = kqueue_get_base_queue(kq, i); + struct kqtailq *queue = kqueue_get_high_queue(kq, i); + do { + while (error == 0 && (kn = TAILQ_FIRST(queue)) != NULL) { + error = knote_process(kn, callback, callback_data, process_data, p); + if (error == EJUSTRETURN) { + error = 0; + } else { + nevents++; + } + /* error is EWOULDBLOCK when the out event array is full */ + } + } while (error == 0 && queue-- > base_queue); + + if ((kq->kq_state & KQ_WORKQ) == 0) { + kqueue_end_processing(kq, i, nevents, flags); + } + + if (error == EWOULDBLOCK) { + /* break out if no more space for additional events */ + error = 0; + break; + } + } while (i-- > end_index); + + *countp = nevents; + return (error); +} + +static void +kqueue_scan_continue(void *data, wait_result_t wait_result) +{ + thread_t self = current_thread(); + uthread_t ut = (uthread_t)get_bsdthread_info(self); + struct _kqueue_scan * cont_args = &ut->uu_kevent.ss_kqueue_scan; + struct kqueue *kq = (struct kqueue *)data; + 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, current_proc()); + 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, + 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, p); + if (error || count) + break; /* lock still held */ + + /* looks like we have to consider blocking */ + if (first) { + first = 0; + /* convert the timeout to a deadline once */ + if (atvp->tv_sec || atvp->tv_usec) { + uint64_t now; + + clock_get_uptime(&now); + nanoseconds_to_absolutetime((uint64_t)atvp->tv_sec * NSEC_PER_SEC + + atvp->tv_usec * (long)NSEC_PER_USEC, + &deadline); + if (now >= deadline) { + /* non-blocking call */ + error = EWOULDBLOCK; + break; /* lock still held */ + } + deadline -= now; + clock_absolutetime_interval_to_deadline(deadline, &deadline); + } else { + deadline = 0; /* block forever */ + } + + if (continuation) { + uthread_t ut = (uthread_t)get_bsdthread_info(current_thread()); + struct _kqueue_scan *cont_args = &ut->uu_kevent.ss_kqueue_scan; + + cont_args->call = callback; + cont_args->cont = continuation; + cont_args->deadline = deadline; + cont_args->data = 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 (kqueue_begin_processing(kq, QOS_INDEX_KQFILE, 0) == -1) { + kqunlock(kq); + return (0); + } + + queue = kqueue_get_base_queue(kq, 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, QOS_INDEX_KQFILE); + while ((kn = (struct knote *)TAILQ_FIRST(suppressq)) != NULL) { + unsigned peek = 1; + + assert(!knoteuse_needs_boost(kn, NULL)); + + /* If didn't vanish while suppressed - peek at it */ + if (kqlock2knoteuse(kq, kn, KNUSE_NONE)) { + peek = knote_fops(kn)->f_peek(kn); + + /* if it dropped while getting lock - move on */ + if (!knoteuse2kqlock(kq, kn, KNUSE_NONE)) + continue; + } + + /* unsuppress it */ + knote_unsuppress(kn); + + /* has data or it has to report a vanish */ + if (peek > 0) { + retnum = 1; + goto out; + } + } + } + +out: + kqueue_end_processing(kq, QOS_INDEX_KQFILE, retnum, 0); + 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); +} + +/*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); + + assert((kqf->kqf_state & KQ_WORKQ) == 0); + + if (parentkq == kq || + kn->kn_filter != EVFILT_READ) { + kn->kn_flags = EV_ERROR; + kn->kn_data = 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. + */ + + kqlock(parentkq); + if (parentkq->kq_level > 0 && + parentkq->kq_level < kq->kq_level) + { + kqunlock(parentkq); + kn->kn_flags = EV_ERROR; + kn->kn_data = EINVAL; + return 0; + } else { + /* set parent level appropriately */ + if (parentkq->kq_level == 0) + parentkq->kq_level = 2; + if (parentkq->kq_level < kq->kq_level + 1) + parentkq->kq_level = kq->kq_level + 1; + kqunlock(parentkq); + + kn->kn_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 { - kq->kq_state |= (iskev64 ? KQ_KEV64 : KQ_KEV32); + 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); +} - /* register all the change requests the user provided... */ - noutputs = 0; - while (nchanges > 0 && error == 0) { - error = kevent_copyin(&changelist, &kev, p, iskev64); - if (error) - break; +/* + * Interact with the pthread kext to request a servicing there. + * Eventually, this will request threads at specific QoS levels. + * For now, it only requests a dispatch-manager-QoS thread, and + * only one-at-a-time. + * + * - 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 +kqworkq_request_thread( + struct kqworkq *kqwq, + kq_index_t qos_index) +{ + struct kqrequest *kqr; - kev.flags &= ~EV_SYSFLAGS; - error = kevent_register(kq, &kev, p); - if ((error || (kev.flags & EV_RECEIPT)) && nevents > 0) { - kev.flags = EV_ERROR; - kev.data = error; - error = kevent_copyout(&kev, &ueventlist, p, iskev64); - if (error == 0) { - nevents--; - noutputs++; - } - } - nchanges--; - } + assert(kqwq->kqwq_state & KQ_WORKQ); + assert(qos_index < KQWQ_NQOS); - /* store the continuation/completion data in the uthread */ - ut = (uthread_t)get_bsdthread_info(current_thread()); - cont_args = &ut->uu_kevent.ss_kevent; - cont_args->fp = fp; - cont_args->fd = fd; - cont_args->retval = retval; - cont_args->eventlist = ueventlist; - cont_args->eventcount = nevents; - cont_args->eventout = noutputs; - cont_args->eventsize = iskev64; + kqr = kqworkq_get_request(kqwq, qos_index); - if (nevents > 0 && noutputs == 0 && error == 0) - error = kqueue_scan(kq, kevent_callback, - kevent_continue, cont_args, - &atv, p); - kevent_continue(kq, cont_args, error); + assert(kqr->kqr_state & KQR_WAKEUP); -errorout: - fp_drop(p, fd, fp, 0); - return (error); -} + /* + * If we have already requested a thread, and it hasn't + * started processing yet, there's no use hammering away + * on the pthread kext. + */ + if (kqr->kqr_state & KQR_THREQUESTED) + return; + + assert((kqr->kqr_state & KQR_BOUND) == 0); + + /* request additional workq threads if appropriate */ + if (pthread_functions != NULL && + pthread_functions->workq_reqthreads != NULL) { + unsigned int flags = KEVENT_FLAG_WORKQ; + unsigned long priority; + thread_t wqthread; + + /* Compute the appropriate pthread priority */ + priority = qos_from_qos_index(qos_index); +#if 0 + /* JMM - for now remain compatible with old invocations */ + /* set the over-commit flag on the request if needed */ + if (kqr->kqr_state & KQR_THOVERCOMMIT) + priority |= _PTHREAD_PRIORITY_OVERCOMMIT_FLAG; +#endif /* 0 */ + + /* Compute a priority based on qos_index. */ + struct workq_reqthreads_req_s request = { + .priority = priority, + .count = 1 + }; + + /* mark that we are making a request */ + kqr->kqr_state |= KQR_THREQUESTED; + if (qos_index == KQWQ_QOS_MANAGER) + kqr->kqr_state |= KQWQ_THMANAGER; + + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWQ_THREQUEST), + 0, qos_index, + (((uintptr_t)kqr->kqr_override_index << 8) | + (uintptr_t)kqr->kqr_state)); + wqthread = (*pthread_functions->workq_reqthreads)(kqwq->kqwq_p, 1, &request); + + /* We've been switched to the emergency/manager thread */ + if (wqthread == (thread_t)-1) { + assert(qos_index != KQWQ_QOS_MANAGER); + kqr->kqr_state |= KQWQ_THMANAGER; + return; + } + + /* + * bind the returned thread identity + * This goes away when we switch to synchronous callback + * binding from the pthread kext. + */ + if (wqthread != NULL) { + kqworkq_bind_thread_impl(kqwq, qos_index, wqthread, flags); + } + } +} /* - * kevent_callback - callback for each individual event + * If we aren't already busy processing events [for this QoS], + * request workq thread support as appropriate. * - * called with nothing locked - * caller holds a reference on the kqueue + * 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 int -kevent_callback(__unused struct kqueue *kq, struct kevent64_s *kevp, - void *data) +static void +kqworkq_request_help( + struct kqworkq *kqwq, + kq_index_t qos_index) { - struct _kevent *cont_args; - int error; - int iskev64; + struct kqrequest *kqr; - cont_args = (struct _kevent *)data; - assert(cont_args->eventout < cont_args->eventcount); + /* convert to thread qos value */ + assert(qos_index < KQWQ_NQOS); + + kqwq_req_lock(kqwq); + kqr = kqworkq_get_request(kqwq, qos_index); - iskev64 = cont_args->eventsize; + if ((kqr->kqr_state & KQR_WAKEUP) == 0) { + /* Indicate that we needed help from this request */ + kqr->kqr_state |= KQR_WAKEUP; - /* - * Copy out the appropriate amount of event data for this user. - */ - error = kevent_copyout(kevp, &cont_args->eventlist, current_proc(), - iskev64); + /* Go assure a thread request has been made */ + kqworkq_request_thread(kqwq, qos_index); + } + kqwq_req_unlock(kqwq); +} + +static void +kqworkloop_threadreq_impl(struct kqworkloop *kqwl, kq_index_t qos_index) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; + unsigned long pri = pthread_priority_for_kqrequest(kqr, qos_index); + int op, ret; + + assert((kqr->kqr_state & (KQR_THREQUESTED | KQR_BOUND)) == KQR_THREQUESTED); /* - * If there isn't space for additional events, return - * a harmless error to stop the processing here + * New-style thread request supported. Provide + * the pthread kext a pointer to a workq_threadreq_s + * structure for its use until a corresponding + * workloop_fulfill_threqreq callback. */ - if (error == 0 && ++cont_args->eventout == cont_args->eventcount) - error = EWOULDBLOCK; - return (error); -} + if (current_proc() == kqwl->kqwl_kqueue.kq_p) { + op = WORKQ_THREADREQ_WORKLOOP_NO_THREAD_CALL; + } else { + op = WORKQ_THREADREQ_WORKLOOP; + } +again: + ret = (*pthread_functions->workq_threadreq)(kqwl->kqwl_p, &kqr->kqr_req, + WORKQ_THREADREQ_WORKLOOP, pri, 0); + switch (ret) { + case ENOTSUP: + assert(op == WORKQ_THREADREQ_WORKLOOP_NO_THREAD_CALL); + op = WORKQ_THREADREQ_WORKLOOP; + goto again; + + case ECANCELED: + case EINVAL: + /* + * 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. + */ + kqueue_release((struct kqueue *)kqwl, KQUEUE_CANT_BE_LAST_REF); + kqr->kqr_state &= ~KQR_THREQUESTED; + kqr->kqr_state |= KQR_DRAIN; + break; -/* - * kevent_description - format a description of a kevent for diagnostic output - * - * called with a 128-byte string buffer - */ + case EAGAIN: + assert(op == WORKQ_THREADREQ_WORKLOOP_NO_THREAD_CALL); + act_set_astkevent(current_thread(), AST_KEVENT_REDRIVE_THREADREQ); + break; -char * -kevent_description(struct kevent64_s *kevp, char *s, size_t n) + default: + assert(ret == 0); + } +} + +static void +kqworkloop_threadreq_modify(struct kqworkloop *kqwl, kq_index_t qos_index) { - snprintf(s, n, - "kevent=" - "{.ident=%#llx, .filter=%d, .flags=%#x, .fflags=%#x, .data=%#llx, .udata=%#llx, .ext[0]=%#llx, .ext[1]=%#llx}", - kevp->ident, - kevp->filter, - kevp->flags, - kevp->fflags, - kevp->data, - kevp->udata, - kevp->ext[0], - kevp->ext[1]); + struct kqrequest *kqr = &kqwl->kqwl_request; + unsigned long pri = pthread_priority_for_kqrequest(kqr, qos_index); + int ret, op = WORKQ_THREADREQ_CHANGE_PRI_NO_THREAD_CALL; - return (s); + assert((kqr->kqr_state & (KQR_THREQUESTED | KQR_BOUND)) == KQR_THREQUESTED); + + if (current_proc() == kqwl->kqwl_kqueue.kq_p) { + op = WORKQ_THREADREQ_CHANGE_PRI_NO_THREAD_CALL; + } else { + op = WORKQ_THREADREQ_CHANGE_PRI; + } +again: + ret = (*pthread_functions->workq_threadreq_modify)(kqwl->kqwl_p, + &kqr->kqr_req, op, pri, 0); + switch (ret) { + case ENOTSUP: + assert(op == WORKQ_THREADREQ_CHANGE_PRI_NO_THREAD_CALL); + op = WORKQ_THREADREQ_CHANGE_PRI; + goto again; + + case EAGAIN: + assert(op == WORKQ_THREADREQ_WORKLOOP_NO_THREAD_CALL); + act_set_astkevent(current_thread(), AST_KEVENT_REDRIVE_THREADREQ); + break; + + case ECANCELED: + case EINVAL: + case 0: + break; + + default: + assert(ret == 0); + } } /* - * kevent_register - add a new event to a kqueue - * - * Creates a mapping between the event source and - * the kqueue via a knote data structure. + * Interact with the pthread kext to request a servicing thread. + * This will request a single thread at the highest QoS level + * for which there is work (whether that was the requested QoS + * for an event or an override applied to a lower-QoS request). * - * Because many/most the event sources are file - * descriptor related, the knote is linked off - * the filedescriptor table for quick access. + * - Caller holds the workloop request lock * - * called with nothing locked - * caller holds a reference on the kqueue + * - May be called with the kqueue's wait queue set locked, + * so cannot do anything that could recurse on that. */ - -int -kevent_register(struct kqueue *kq, struct kevent64_s *kev, - __unused struct proc *ctxp) +static void +kqworkloop_request_thread(struct kqworkloop *kqwl, kq_index_t qos_index) { - struct proc *p = kq->kq_p; - struct filedesc *fdp = p->p_fd; - struct filterops *fops; - struct fileproc *fp = NULL; - struct knote *kn = NULL; - int error = 0; + struct kqrequest *kqr; - if (kev->filter < 0) { - if (kev->filter + EVFILT_SYSCOUNT < 0) - return (EINVAL); - fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ - } else { + assert(kqwl->kqwl_state & KQ_WORKLOOP); + + kqr = &kqwl->kqwl_request; + + assert(kqwl->kqwl_owner == THREAD_NULL); + assert((kqr->kqr_state & KQR_BOUND) == 0); + assert((kqr->kqr_state & KQR_THREQUESTED) == 0); + assert(!(kqwl->kqwl_kqueue.kq_state & KQ_NO_WQ_THREAD)); + + /* If we're draining thread requests, just bail */ + if (kqr->kqr_state & KQR_DRAIN) + return; + + if (pthread_functions != NULL && + pthread_functions->workq_threadreq != NULL) { /* - * XXX - * filter attach routine is responsible for insuring that - * the identifier can be attached to it. + * set request state flags, etc... before calling pthread + * This assures they are set before a possible synchronous + * callback to workloop_fulfill_threadreq(). */ - printf("unknown filter: %d\n", kev->filter); - return (EINVAL); - } + kqr->kqr_state |= KQR_THREQUESTED; -restart: - /* this iocount needs to be dropped if it is not registered */ - proc_fdlock(p); - if (fops->f_isfd && (error = fp_lookup(p, kev->ident, &fp, 1)) != 0) { - proc_fdunlock(p); - return (error); - } + /* Add a thread request reference on the kqueue. */ + kqueue_retain((struct kqueue *)kqwl); - if (fops->f_isfd) { - /* fd-based knotes are linked off the fd table */ - if (kev->ident < (u_int)fdp->fd_knlistsize) { - SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) - if (kq == kn->kn_kq && - kev->filter == kn->kn_filter) - break; - } + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_THREQUEST), + kqwl->kqwl_dynamicid, + 0, qos_index, kqr->kqr_state); + kqworkloop_threadreq_impl(kqwl, qos_index); } else { - /* hash non-fd knotes here too */ - if (fdp->fd_knhashmask != 0) { - struct klist *list; - - list = &fdp->fd_knhash[ - KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; - SLIST_FOREACH(kn, list, kn_link) - if (kev->ident == kn->kn_id && - kq == kn->kn_kq && - kev->filter == kn->kn_filter) - break; - } + panic("kqworkloop_request_thread"); + return; } +} - /* - * kn now contains the matching knote, or NULL if no match - */ - if (kn == NULL) { - if ((kev->flags & (EV_ADD|EV_DELETE)) == EV_ADD) { - kn = knote_alloc(); - if (kn == NULL) { - proc_fdunlock(p); - error = ENOMEM; - goto done; - } - kn->kn_fp = fp; - kn->kn_kq = kq; - kn->kn_tq = &kq->kq_head; - kn->kn_fop = fops; - kn->kn_sfflags = kev->fflags; - kn->kn_sdata = kev->data; - kev->fflags = 0; - kev->data = 0; - kn->kn_kevent = *kev; - kn->kn_inuse = 1; /* for f_attach() */ - kn->kn_status = KN_ATTACHING; +static void +kqworkloop_update_sync_override_state(struct kqworkloop *kqwl, boolean_t sync_ipc_override) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; + kqwl_req_lock(kqwl); + kqr->kqr_has_sync_override = sync_ipc_override; + kqwl_req_unlock(kqwl); - /* before anyone can find it */ - if (kev->flags & EV_DISABLE) - kn->kn_status |= KN_DISABLED; +} - error = knote_fdpattach(kn, fdp, p); - proc_fdunlock(p); +static inline kq_index_t +kqworkloop_combined_qos(struct kqworkloop *kqwl, boolean_t *ipc_override_is_sync) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; + kq_index_t override; - if (error) { - knote_free(kn); - goto done; - } + *ipc_override_is_sync = FALSE; + override = MAX(MAX(kqr->kqr_qos_index, kqr->kqr_override_index), + kqr->kqr_dsync_waiters_qos); - /* - * apply reference count to knote structure, and - * do not release it at the end of this routine. - */ - fp = NULL; + if (kqr->kqr_sync_suppress_count > 0 || kqr->kqr_has_sync_override) { + *ipc_override_is_sync = TRUE; + override = THREAD_QOS_USER_INTERACTIVE; + } + return override; +} - error = fops->f_attach(kn); +static inline void +kqworkloop_request_fire_r2k_notification(struct kqworkloop *kqwl) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; - kqlock(kq); + kqwl_req_held(kqwl); - if (error != 0) { - /* - * Failed to attach correctly, so drop. - * All other possible users/droppers - * have deferred to us. - */ - kn->kn_status |= KN_DROPPING; - kqunlock(kq); - knote_drop(kn, p); - goto done; - } else if (kn->kn_status & KN_DROPPING) { - /* - * Attach succeeded, but someone else - * deferred their drop - now we have - * to do it for them (after detaching). - */ - kqunlock(kq); - kn->kn_fop->f_detach(kn); - knote_drop(kn, p); - goto done; - } - kn->kn_status &= ~KN_ATTACHING; - kqunlock(kq); - } else { - proc_fdunlock(p); - error = ENOENT; - goto done; + if (kqr->kqr_state & KQR_R2K_NOTIF_ARMED) { + assert(kqr->kqr_state & KQR_BOUND); + 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) +{ + const uint8_t KQWL_STAYACTIVE_FIRED_BIT = (1 << 0); + + struct kqrequest *kqr = &kqwl->kqwl_request; + boolean_t old_ipc_override_is_sync = FALSE; + kq_index_t old_qos = kqworkloop_combined_qos(kqwl, &old_ipc_override_is_sync); + struct kqueue *kq = &kqwl->kqwl_kqueue; + bool static_thread = (kq->kq_state & KQ_NO_WQ_THREAD); + kq_index_t i; + + /* must hold the kqr lock */ + kqwl_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); + assert(!static_thread); + } + if (kqr->kqr_wakeup_indexes & (1 << qos)) { + assert(kqr->kqr_state & KQR_WAKEUP); + break; } - } else { - /* existing knote - get kqueue lock */ - kqlock(kq); - proc_fdunlock(p); - if (kev->flags & EV_DELETE) { - knote_dequeue(kn); - kn->kn_status |= KN_DISABLED; - if (kqlock2knotedrop(kq, kn)) { - kn->kn_fop->f_detach(kn); - knote_drop(kn, p); + kqr->kqr_wakeup_indexes |= (1 << qos); + kqr->kqr_state |= KQR_WAKEUP; + kqworkloop_request_fire_r2k_notification(kqwl); + goto recompute_async; + + 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_async; } - goto done; } + break; - /* update status flags for existing knote */ - if (kev->flags & EV_DISABLE) { - knote_dequeue(kn); - kn->kn_status |= KN_DISABLED; - } else if (kev->flags & EV_ENABLE) { - kn->kn_status &= ~KN_DISABLED; - if (kn->kn_status & KN_ACTIVE) - knote_enqueue(kn); + case KQWL_UTQ_RECOMPUTE_WAKEUP_QOS: + kqlock_held(kq); // to look at kq_queues + kqr->kqr_has_sync_override = FALSE; + i = KQWL_BUCKET_STAYACTIVE; + if (TAILQ_EMPTY(&kqr->kqr_suppressed)) { + kqr->kqr_override_index = THREAD_QOS_UNSPECIFIED; } - - /* - * The user may change some filter values after the - * initial EV_ADD, but doing so will not reset any - * filter which have already been triggered. - */ - kn->kn_kevent.udata = kev->udata; - if (fops->f_isfd || fops->f_touch == NULL) { - kn->kn_sfflags = kev->fflags; - kn->kn_sdata = kev->data; + if (!TAILQ_EMPTY(&kq->kq_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; } - - /* - * If somebody is in the middle of dropping this - * knote - go find/insert a new one. But we have - * wait for this one to go away first. Attaches - * running in parallel may also drop/modify the - * knote. Wait for those to complete as well and - * then start over if we encounter one. - */ - if (!kqlock2knoteusewait(kq, kn)) { - /* kqueue, proc_fdlock both unlocked */ - goto restart; + for (i = THREAD_QOS_UNSPECIFIED + 1; i < KQWL_BUCKET_STAYACTIVE; i++) { + if (!TAILQ_EMPTY(&kq->kq_queue[i])) { + kqr->kqr_wakeup_indexes |= (1 << i); + struct knote *kn = TAILQ_FIRST(&kqwl->kqwl_kqueue.kq_queue[i]); + if (i == THREAD_QOS_USER_INTERACTIVE && + kn->kn_qos_override_is_sync) { + kqr->kqr_has_sync_override = TRUE; + } + } + } + if (kqr->kqr_wakeup_indexes) { + kqr->kqr_state |= KQR_WAKEUP; + kqworkloop_request_fire_r2k_notification(kqwl); + } else { + kqr->kqr_state &= ~KQR_WAKEUP; } + assert(qos == THREAD_QOS_UNSPECIFIED); + goto recompute_async; + case KQWL_UTQ_RESET_WAKEUP_OVERRIDE: + kqr->kqr_override_index = THREAD_QOS_UNSPECIFIED; + assert(qos == THREAD_QOS_UNSPECIFIED); + goto recompute_async; + + case KQWL_UTQ_UPDATE_WAKEUP_OVERRIDE: + recompute_async: /* - * Call touch routine to notify filter of changes - * in filter values. + * When modifying the wakeup QoS or the async 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 (!fops->f_isfd && fops->f_touch != NULL) - fops->f_touch(kn, kev, EVENT_REGISTER); - } - /* still have use ref on knote */ + 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; - /* - * If the knote is not marked to always stay enqueued, - * invoke the filter routine to see if it should be - * enqueued now. - */ - if ((kn->kn_status & KN_STAYQUEUED) == 0 && kn->kn_fop->f_event(kn, 0)) { - if (knoteuse2kqlock(kq, kn)) - knote_activate(kn, 1); - kqunlock(kq); - } else { - knote_put(kn); - } + case KQWL_UTQ_REDRIVE_EVENTS: + break; -done: - if (fp != NULL) - fp_drop(p, kev->ident, fp, 0); - return (error); -} + case KQWL_UTQ_SET_ASYNC_QOS: + filt_wlheld(kqwl); + kqr->kqr_qos_index = qos; + break; + case KQWL_UTQ_SET_SYNC_WAITERS_QOS: + filt_wlheld(kqwl); + kqr->kqr_dsync_waiters_qos = qos; + break; -/* - * knote_process - process a triggered event - * - * Validate that it is really still a triggered event - * by calling the filter routines (if necessary). Hold - * a use reference on the knote to avoid it being detached. - * If it is still considered triggered, invoke the callback - * routine provided and move it to the provided inprocess - * queue. - * - * caller holds a reference on the kqueue. - * kqueue locked on entry and exit - but may be dropped - */ -static int -knote_process(struct knote *kn, - kevent_callback_t callback, - void *data, - struct kqtailq *inprocessp, - struct proc *p) -{ - struct kqueue *kq = kn->kn_kq; - struct kevent64_s kev; - int touch; - int result; - int error; + default: + panic("unknown kqwl thread qos update operation: %d", op); + } + + boolean_t new_ipc_override_is_sync = FALSE; + kq_index_t new_qos = kqworkloop_combined_qos(kqwl, &new_ipc_override_is_sync); + thread_t kqwl_owner = kqwl->kqwl_owner; + thread_t servicer = kqr->kqr_thread; + __assert_only int ret; /* - * Determine the kevent state we want to return. - * - * Some event states need to be revalidated before returning - * them, others we take the snapshot at the time the event - * was enqueued. - * - * Events with non-NULL f_touch operations must be touched. - * Triggered events must fill in kev for the callback. - * - * Convert our lock to a use-count and call the event's - * filter routine(s) to update. + * Apply the diffs to the owner if applicable */ - if ((kn->kn_status & KN_DISABLED) != 0) { - result = 0; - touch = 0; - } else { - int revalidate; + if (filt_wlowner_is_valid(kqwl_owner)) { +#if 0 + /* JMM - need new trace hooks for owner overrides */ + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_THADJUST), + kqwl->kqwl_dynamicid, + (kqr->kqr_state & KQR_BOUND) ? thread_tid(kqwl_owner) : 0, + (kqr->kqr_qos_index << 8) | new_qos, + (kqr->kqr_override_index << 8) | kqr->kqr_state); +#endif + if (new_qos == kqr->kqr_dsync_owner_qos) { + // nothing to do + } else if (kqr->kqr_dsync_owner_qos == THREAD_QOS_UNSPECIFIED) { + thread_add_ipc_override(kqwl_owner, new_qos); + } else if (new_qos == THREAD_QOS_UNSPECIFIED) { + thread_drop_ipc_override(kqwl_owner); + } else /* kqr->kqr_dsync_owner_qos != new_qos */ { + thread_update_ipc_override(kqwl_owner, new_qos); + } + kqr->kqr_dsync_owner_qos = new_qos; + + if (new_ipc_override_is_sync && + !kqr->kqr_owner_override_is_sync) { + thread_add_sync_ipc_override(kqwl_owner); + } else if (!new_ipc_override_is_sync && + kqr->kqr_owner_override_is_sync) { + thread_drop_sync_ipc_override(kqwl_owner); + } + kqr->kqr_owner_override_is_sync = new_ipc_override_is_sync; + } - result = 1; - revalidate = ((kn->kn_status & KN_STAYQUEUED) != 0 || - (kn->kn_flags & EV_ONESHOT) == 0); - touch = (!kn->kn_fop->f_isfd && kn->kn_fop->f_touch != NULL); - - if (revalidate || touch) { - if (revalidate) - knote_deactivate(kn); - - /* call the filter/touch routines with just a ref */ - if (kqlock2knoteuse(kq, kn)) { - /* if we have to revalidate, call the filter */ - if (revalidate) { - result = kn->kn_fop->f_event(kn, 0); - } + /* + * apply the diffs to the servicer + */ + if (static_thread) { + /* + * Statically bound thread + * + * These threads don't participates in QoS overrides today, just wakeup + * the thread blocked on this kqueue if a new event arrived. + */ - /* - * capture the kevent data - using touch if - * specified - */ - if (result && touch) { - kn->kn_fop->f_touch(kn, &kev, - EVENT_PROCESS); - } + switch (op) { + case KQWL_UTQ_UPDATE_WAKEUP_QOS: + case KQWL_UTQ_UPDATE_STAYACTIVE_QOS: + case KQWL_UTQ_RECOMPUTE_WAKEUP_QOS: + break; - /* - * convert back to a kqlock - bail if the knote - * went away - */ - if (!knoteuse2kqlock(kq, kn)) { - return (EJUSTRETURN); - } else if (result) { - /* - * if revalidated as alive, make sure - * it's active - */ - if (!(kn->kn_status & KN_ACTIVE)) { - knote_activate(kn, 0); - } + case KQWL_UTQ_RESET_WAKEUP_OVERRIDE: + case KQWL_UTQ_UPDATE_WAKEUP_OVERRIDE: + case KQWL_UTQ_REDRIVE_EVENTS: + case KQWL_UTQ_SET_ASYNC_QOS: + case KQWL_UTQ_SET_SYNC_WAITERS_QOS: + panic("should never be called"); + break; + } - /* - * capture all events that occurred - * during filter - */ - if (!touch) { - kev = kn->kn_kevent; - } + kqlock_held(kq); - } else if ((kn->kn_status & KN_STAYQUEUED) == 0) { - /* - * was already dequeued, so just bail on - * this one - */ - return (EJUSTRETURN); - } - } else { - return (EJUSTRETURN); + if ((kqr->kqr_state & KQR_BOUND) && (kqr->kqr_state & KQR_WAKEUP)) { + assert(servicer && !is_workqueue_thread(servicer)); + 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); } - } else { - kev = kn->kn_kevent; } - } - - /* move knote onto inprocess queue */ - assert(kn->kn_tq == &kq->kq_head); - TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); - kn->kn_tq = inprocessp; - TAILQ_INSERT_TAIL(inprocessp, kn, kn_tqe); - - /* - * Determine how to dispatch the knote for future event handling. - * not-fired: just return (do not callout). - * One-shot: deactivate it. - * Clear: deactivate and clear the state. - * Dispatch: don't clear state, just deactivate it and mark it disabled. - * All others: just leave where they are. - */ + } else 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 (result == 0) { - return (EJUSTRETURN); - } else if ((kn->kn_flags & EV_ONESHOT) != 0) { - knote_deactivate(kn); - if (kqlock2knotedrop(kq, kn)) { - kn->kn_fop->f_detach(kn); - knote_drop(kn, p); + if (kqwl_owner == THREAD_NULL && (kqr->kqr_state & KQR_WAKEUP)) { + kqworkloop_request_thread(kqwl, new_qos); } - } else if ((kn->kn_flags & (EV_CLEAR | EV_DISPATCH)) != 0) { - if ((kn->kn_flags & EV_DISPATCH) != 0) { - /* deactivate and disable all dispatch knotes */ - knote_deactivate(kn); - kn->kn_status |= KN_DISABLED; - } else if (!touch || kn->kn_fflags == 0) { - /* only deactivate if nothing since the touch */ - knote_deactivate(kn); - } - if (!touch && (kn->kn_flags & EV_CLEAR) != 0) { - /* manually clear non-touch knotes */ - kn->kn_data = 0; - kn->kn_fflags = 0; + } else if ((kqr->kqr_state & KQR_BOUND) == 0 && + (kqwl_owner || (kqr->kqr_state & KQR_WAKEUP) == 0)) { + /* + * No servicer, thread request in flight we want to cancel + * + * We just got rid of the last knote of the kqueue or noticed an owner + * with a thread request still in flight, take it back. + */ + ret = (*pthread_functions->workq_threadreq_modify)(kqwl->kqwl_p, + &kqr->kqr_req, WORKQ_THREADREQ_CANCEL, 0, 0); + if (ret == 0) { + kqr->kqr_state &= ~KQR_THREQUESTED; + kqueue_release(kq, KQUEUE_CANT_BE_LAST_REF); } - kqunlock(kq); } else { + boolean_t qos_changed = FALSE; + /* - * leave on inprocess queue. We'll - * move all the remaining ones back - * the kq queue and wakeup any - * waiters when we are done. + * Servicer or request is in flight + * + * Just apply the diff to the servicer or the thread request */ - kqunlock(kq); + if (kqr->kqr_state & KQR_BOUND) { + servicer = kqr->kqr_thread; + struct uthread *ut = get_bsdthread_info(servicer); + if (ut->uu_kqueue_qos_index != new_qos) { + if (ut->uu_kqueue_qos_index == THREAD_QOS_UNSPECIFIED) { + thread_add_ipc_override(servicer, new_qos); + } else if (new_qos == THREAD_QOS_UNSPECIFIED) { + thread_drop_ipc_override(servicer); + } else /* ut->uu_kqueue_qos_index != new_qos */ { + thread_update_ipc_override(servicer, new_qos); + } + ut->uu_kqueue_qos_index = new_qos; + qos_changed = TRUE; + } + + if (new_ipc_override_is_sync != ut->uu_kqueue_override_is_sync) { + if (new_ipc_override_is_sync && + !ut->uu_kqueue_override_is_sync) { + thread_add_sync_ipc_override(servicer); + } else if (!new_ipc_override_is_sync && + ut->uu_kqueue_override_is_sync) { + thread_drop_sync_ipc_override(servicer); + } + ut->uu_kqueue_override_is_sync = new_ipc_override_is_sync; + qos_changed = TRUE; + } + } else if (old_qos != new_qos) { + assert(new_qos); + kqworkloop_threadreq_modify(kqwl, new_qos); + qos_changed = TRUE; + } + if (qos_changed) { + servicer = kqr->kqr_thread; + KDBG_FILTERED(KEV_EVTID(BSD_KEVENT_KQWL_THADJUST), + kqwl->kqwl_dynamicid, + (kqr->kqr_state & KQR_BOUND) ? thread_tid(servicer) : 0, + (kqr->kqr_qos_index << 16) | (new_qos << 8) | new_ipc_override_is_sync, + (kqr->kqr_override_index << 8) | kqr->kqr_state); + } } +} - /* callback to handle each event as we find it */ - error = (callback)(kq, &kev, data); +static void +kqworkloop_request_help(struct kqworkloop *kqwl, kq_index_t qos_index) +{ + /* convert to thread qos value */ + assert(qos_index < KQWL_NBUCKETS); - kqlock(kq); - return (error); + kqwl_req_lock(kqwl); + kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_WAKEUP_QOS, qos_index); + kqwl_req_unlock(kqwl); } /* - * 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. + * These arrays described the low and high qindexes for a given qos_index. + * The values come from the chart in (must stay in sync). */ -static int -kqueue_begin_processing(struct kqueue *kq) -{ - for (;;) { - if (kq->kq_count == 0) { - return (-1); - } +static kq_index_t _kqwq_base_index[KQWQ_NQOS] = {0, 0, 6, 11, 15, 18, 20, 21}; +static kq_index_t _kqwq_high_index[KQWQ_NQOS] = {0, 5, 10, 14, 17, 19, 20, 21}; - /* if someone else is processing the queue, wait */ - if (kq->kq_nprocess != 0) { - wait_queue_assert_wait((wait_queue_t)kq->kq_wqs, - &kq->kq_nprocess, THREAD_UNINT, 0); - kq->kq_state |= KQ_PROCWAIT; - kqunlock(kq); - thread_block(THREAD_CONTINUE_NULL); - kqlock(kq); - } else { - kq->kq_nprocess = 1; - return (0); - } +static struct kqtailq * +kqueue_get_base_queue(struct kqueue *kq, kq_index_t qos_index) +{ + if (kq->kq_state & KQ_WORKQ) { + assert(qos_index < KQWQ_NQOS); + return &kq->kq_queue[_kqwq_base_index[qos_index]]; + } else if (kq->kq_state & KQ_WORKLOOP) { + assert(qos_index < KQWL_NBUCKETS); + return &kq->kq_queue[qos_index]; + } else { + assert(qos_index == QOS_INDEX_KQFILE); + return &kq->kq_queue[QOS_INDEX_KQFILE]; } } -/* - * Called with kqueue lock held. - */ -static void -kqueue_end_processing(struct kqueue *kq) +static struct kqtailq * +kqueue_get_high_queue(struct kqueue *kq, kq_index_t qos_index) { - kq->kq_nprocess = 0; - if (kq->kq_state & KQ_PROCWAIT) { - kq->kq_state &= ~KQ_PROCWAIT; - wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, - &kq->kq_nprocess, THREAD_AWAKENED); + if (kq->kq_state & KQ_WORKQ) { + assert(qos_index < KQWQ_NQOS); + return &kq->kq_queue[_kqwq_high_index[qos_index]]; + } else if (kq->kq_state & KQ_WORKLOOP) { + assert(qos_index < KQWL_NBUCKETS); + return &kq->kq_queue[KQWL_BUCKET_STAYACTIVE]; + } else { + assert(qos_index == QOS_INDEX_KQFILE); + return &kq->kq_queue[QOS_INDEX_KQFILE]; } } -/* - * kqueue_process - process the triggered events in a kqueue - * - * Walk the queued knotes and validate that they are - * really still triggered events by calling the filter - * routines (if necessary). Hold a use reference on - * the knote to avoid it being detached. For each event - * that is still considered triggered, invoke the - * callback routine provided. - * - * caller holds a reference on the kqueue. - * kqueue locked on entry and exit - but may be dropped - * kqueue list locked (held for duration of call) - */ - static int -kqueue_process(struct kqueue *kq, - kevent_callback_t callback, - void *data, - int *countp, - struct proc *p) +kqueue_queue_empty(struct kqueue *kq, kq_index_t qos_index) { - struct kqtailq inprocess; - struct knote *kn; - int nevents; - int error; - - TAILQ_INIT(&inprocess); - - if (kqueue_begin_processing(kq) == -1) { - *countp = 0; - /* Nothing to process */ - return (0); - } + struct kqtailq *base_queue = kqueue_get_base_queue(kq, qos_index); + struct kqtailq *queue = kqueue_get_high_queue(kq, qos_index); + + do { + if (!TAILQ_EMPTY(queue)) + return 0; + } while (queue-- > base_queue); + return 1; +} - /* - * Clear any pre-posted status from previous runs, so we - * only detect events that occur during this run. - */ - wait_queue_sub_clearrefs(kq->kq_wqs); +static struct kqtailq * +kqueue_get_suppressed_queue(struct kqueue *kq, kq_index_t qos_index) +{ + struct kqtailq *res; + struct kqrequest *kqr; - /* - * loop through the enqueued knotes, processing each one and - * revalidating those that need it. As they are processed, - * they get moved to the inprocess queue (so the loop can end). - */ - error = 0; - nevents = 0; + if (kq->kq_state & KQ_WORKQ) { + struct kqworkq *kqwq = (struct kqworkq *)kq; - while (error == 0 && - (kn = TAILQ_FIRST(&kq->kq_head)) != NULL) { - error = knote_process(kn, callback, data, &inprocess, p); - if (error == EJUSTRETURN) - error = 0; - else - nevents++; - } + kqr = kqworkq_get_request(kqwq, qos_index); + res = &kqr->kqr_suppressed; + } else if (kq->kq_state & KQ_WORKLOOP) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; - /* - * With the kqueue still locked, move any knotes - * remaining on the inprocess queue back to the - * kq's queue and wake up any waiters. - */ - while ((kn = TAILQ_FIRST(&inprocess)) != NULL) { - assert(kn->kn_tq == &inprocess); - TAILQ_REMOVE(&inprocess, kn, kn_tqe); - kn->kn_tq = &kq->kq_head; - TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); + kqr = &kqwl->kqwl_request; + res = &kqr->kqr_suppressed; + } else { + struct kqfile *kqf = (struct kqfile *)kq; + res = &kqf->kqf_suppressed; } - - kqueue_end_processing(kq); - - *countp = nevents; - return (error); + return res; } - -static void -kqueue_scan_continue(void *data, wait_result_t wait_result) +static kq_index_t +knote_get_queue_index(struct knote *kn) { - thread_t self = current_thread(); - uthread_t ut = (uthread_t)get_bsdthread_info(self); - struct _kqueue_scan * cont_args = &ut->uu_kevent.ss_kqueue_scan; - struct kqueue *kq = (struct kqueue *)data; - int error; - int count; - - /* convert the (previous) wait_result to a proper error */ - switch (wait_result) { - case THREAD_AWAKENED: - kqlock(kq); - error = kqueue_process(kq, cont_args->call, cont_args, &count, - current_proc()); - if (error == 0 && count == 0) { - wait_queue_assert_wait((wait_queue_t)kq->kq_wqs, - KQ_EVENT, THREAD_ABORTSAFE, cont_args->deadline); - kq->kq_state |= KQ_SLEEP; - kqunlock(kq); - thread_block_parameter(kqueue_scan_continue, kq); - /* NOTREACHED */ - } - kqunlock(kq); - break; - case THREAD_TIMED_OUT: - error = EWOULDBLOCK; - break; - case THREAD_INTERRUPTED: - error = EINTR; - break; - default: - panic("%s: - invalid wait_result (%d)", __func__, - wait_result); - error = 0; + kq_index_t override_index = knote_get_qos_override_index(kn); + kq_index_t qos_index = knote_get_qos_index(kn); + struct kqueue *kq = knote_get_kq(kn); + kq_index_t res; + + if (kq->kq_state & KQ_WORKQ) { + res = _kqwq_base_index[qos_index]; + if (override_index > qos_index) + res += override_index - qos_index; + assert(res <= _kqwq_high_index[qos_index]); + } else if (kq->kq_state & KQ_WORKLOOP) { + res = MAX(override_index, qos_index); + assert(res < KQWL_NBUCKETS); + } else { + assert(qos_index == QOS_INDEX_KQFILE); + assert(override_index == QOS_INDEX_KQFILE); + res = QOS_INDEX_KQFILE; } - - /* call the continuation with the results */ - assert(cont_args->cont != NULL); - (cont_args->cont)(kq, cont_args->data, error); + return res; } +static struct kqtailq * +knote_get_queue(struct knote *kn) +{ + kq_index_t qindex = knote_get_queue_index(kn); -/* - * 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. - */ + return &(knote_get_kq(kn))->kq_queue[qindex]; +} -int -kqueue_scan(struct kqueue *kq, - kevent_callback_t callback, - kqueue_continue_t continuation, - void *data, - struct timeval *atvp, - struct proc *p) +static kq_index_t +knote_get_req_index(struct knote *kn) { - thread_continue_t cont = THREAD_CONTINUE_NULL; - uint64_t deadline; - int error; - int first; - - assert(callback != NULL); + return kn->kn_req_index; +} - first = 1; - for (;;) { - wait_result_t wait_result; - int count; +static kq_index_t +knote_get_qos_index(struct knote *kn) +{ + return kn->kn_qos_index; +} - /* - * Make a pass through the kq to find events already - * triggered. - */ - kqlock(kq); - error = kqueue_process(kq, callback, data, &count, p); - if (error || count) - break; /* lock still held */ +static void +knote_set_qos_index(struct knote *kn, kq_index_t qos_index) +{ + struct kqueue *kq = knote_get_kq(kn); + + assert(qos_index < KQWQ_NQOS); + assert((kn->kn_status & KN_QUEUED) == 0); + + if (kq->kq_state & KQ_WORKQ) { + assert(qos_index > THREAD_QOS_UNSPECIFIED); + } else if (kq->kq_state & KQ_WORKLOOP) { + /* XXX this policy decision shouldn't be here */ + if (qos_index == THREAD_QOS_UNSPECIFIED) + qos_index = THREAD_QOS_LEGACY; + } else + qos_index = QOS_INDEX_KQFILE; + + /* always set requested */ + kn->kn_req_index = qos_index; + + /* only adjust in-use qos index when not suppressed */ + if ((kn->kn_status & KN_SUPPRESSED) == 0) + kn->kn_qos_index = qos_index; +} - /* 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; +static void +knote_set_qos_overcommit(struct knote *kn) +{ + struct kqueue *kq = knote_get_kq(kn); + struct kqrequest *kqr; - 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 */ - } + /* turn overcommit on for the appropriate thread request? */ + if (kn->kn_qos & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG) { + if (kq->kq_state & KQ_WORKQ) { + kq_index_t qos_index = knote_get_qos_index(kn); + struct kqworkq *kqwq = (struct kqworkq *)kq; - if (continuation) { - uthread_t ut = (uthread_t)get_bsdthread_info(current_thread()); - struct _kqueue_scan *cont_args = &ut->uu_kevent.ss_kqueue_scan; + kqr = kqworkq_get_request(kqwq, qos_index); - cont_args->call = callback; - cont_args->cont = continuation; - cont_args->deadline = deadline; - cont_args->data = data; - cont = kqueue_scan_continue; - } - } + kqwq_req_lock(kqwq); + kqr->kqr_state |= KQR_THOVERCOMMIT; + kqwq_req_unlock(kqwq); + } else if (kq->kq_state & KQ_WORKLOOP) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; - /* go ahead and wait */ - wait_queue_assert_wait_with_leeway((wait_queue_t)kq->kq_wqs, - KQ_EVENT, THREAD_ABORTSAFE, TIMEOUT_URGENCY_USER_NORMAL, - deadline, 0); - kq->kq_state |= KQ_SLEEP; - kqunlock(kq); - wait_result = thread_block_parameter(cont, kq); - /* NOTREACHED if (continuation != NULL) */ + kqr = &kqwl->kqwl_request; - switch (wait_result) { - case THREAD_AWAKENED: - continue; - case THREAD_TIMED_OUT: - return (EWOULDBLOCK); - case THREAD_INTERRUPTED: - return (EINTR); - default: - panic("%s: - bad wait_result (%d)", __func__, - wait_result); - error = 0; + kqwl_req_lock(kqwl); + kqr->kqr_state |= KQR_THOVERCOMMIT; + kqwl_req_unlock(kqwl); } } - 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) +static kq_index_t +knote_get_qos_override_index(struct knote *kn) { - return (ENXIO); + return kn->kn_qos_override; } -/*ARGSUSED*/ -static int -kqueue_write(__unused struct fileproc *fp, - __unused struct uio *uio, - __unused int flags, - __unused vfs_context_t ctx) +static void +knote_set_qos_override_index(struct knote *kn, kq_index_t override_index, + boolean_t override_is_sync) { - return (ENXIO); + struct kqueue *kq = knote_get_kq(kn); + kq_index_t qos_index = knote_get_qos_index(kn); + kq_index_t old_override_index = knote_get_qos_override_index(kn); + boolean_t old_override_is_sync = kn->kn_qos_override_is_sync; + uint32_t flags = 0; + + assert((kn->kn_status & KN_QUEUED) == 0); + + if (override_index == KQWQ_QOS_MANAGER) { + assert(qos_index == KQWQ_QOS_MANAGER); + } else { + assert(override_index < KQWQ_QOS_MANAGER); + } + + kn->kn_qos_override = override_index; + kn->kn_qos_override_is_sync = override_is_sync; + + /* + * If this is a workq/workloop kqueue, apply the override to the + * servicing thread. + */ + if (kq->kq_state & KQ_WORKQ) { + struct kqworkq *kqwq = (struct kqworkq *)kq; + + assert(qos_index > THREAD_QOS_UNSPECIFIED); + kqworkq_update_override(kqwq, qos_index, override_index); + } else if (kq->kq_state & KQ_WORKLOOP) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + + if ((kn->kn_status & KN_SUPPRESSED) == KN_SUPPRESSED) { + flags = flags | KQWL_UO_UPDATE_SUPPRESS_SYNC_COUNTERS; + + if (override_index == THREAD_QOS_USER_INTERACTIVE + && override_is_sync) { + flags = flags | KQWL_UO_NEW_OVERRIDE_IS_SYNC_UI; + } + + if (old_override_index == THREAD_QOS_USER_INTERACTIVE + && old_override_is_sync) { + flags = flags | KQWL_UO_OLD_OVERRIDE_IS_SYNC_UI; + } + } + + assert(qos_index > THREAD_QOS_UNSPECIFIED); + kqworkloop_update_override(kqwl, qos_index, override_index, flags); + } } -/*ARGSUSED*/ -static int -kqueue_ioctl(__unused struct fileproc *fp, - __unused u_long com, - __unused caddr_t data, - __unused vfs_context_t ctx) +static kq_index_t +knote_get_sync_qos_override_index(struct knote *kn) { - return (ENOTTY); + return kn->kn_qos_sync_override; } -/*ARGSUSED*/ -static int -kqueue_select(struct fileproc *fp, int which, void *wql, - __unused vfs_context_t ctx) +static void +kqworkq_update_override(struct kqworkq *kqwq, kq_index_t qos_index, kq_index_t override_index) { - struct kqueue *kq = (struct kqueue *)fp->f_data; - struct knote *kn; - struct kqtailq inprocessq; - int retnum = 0; + struct kqrequest *kqr; + kq_index_t old_override_index; - if (which != FREAD) - return (0); + if (override_index <= qos_index) { + return; + } - TAILQ_INIT(&inprocessq); + kqr = kqworkq_get_request(kqwq, qos_index); - kqlock(kq); - /* - * If this is the first pass, link the wait queue associated with the - * the kqueue onto the wait queue set for the select(). Normally we - * use selrecord() for this, but it uses the wait queue within the - * selinfo structure and we need to use the main one for the kqueue to - * catch events from KN_STAYQUEUED sources. So we do the linkage manually. - * (The select() call will unlink them when it ends). - */ - if (wql != NULL) { - thread_t cur_act = current_thread(); - struct uthread * ut = get_bsdthread_info(cur_act); + kqwq_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; - kq->kq_state |= KQ_SEL; - wait_queue_link_noalloc((wait_queue_t)kq->kq_wqs, ut->uu_wqset, - (wait_queue_link_t)wql); + /* apply the override to [incoming?] servicing thread */ + if (kqr->kqr_state & KQR_BOUND) { + thread_t wqthread = kqr->kqr_thread; + + /* only apply if non-manager */ + assert(wqthread); + if ((kqr->kqr_state & KQWQ_THMANAGER) == 0) { + if (old_override_index) + thread_update_ipc_override(wqthread, override_index); + else + thread_add_ipc_override(wqthread, override_index); + } + } } + kqwq_req_unlock(kqwq); +} - if (kqueue_begin_processing(kq) == -1) { - kqunlock(kq); - return (0); +/* called with the kqworkq lock held */ +static void +kqworkq_bind_thread_impl( + struct kqworkq *kqwq, + kq_index_t qos_index, + thread_t thread, + unsigned int flags) +{ + /* request lock must be held */ + kqwq_req_held(kqwq); + + struct kqrequest *kqr = kqworkq_get_request(kqwq, qos_index); + assert(kqr->kqr_state & KQR_THREQUESTED); + + if (qos_index == KQWQ_QOS_MANAGER) + flags |= KEVENT_FLAG_WORKQ_MANAGER; + + struct uthread *ut = get_bsdthread_info(thread); + + /* + * If this is a manager, and the manager request bit is + * not set, assure no other thread is bound. If the bit + * is set, make sure the old thread is us (or not set). + */ + if (flags & KEVENT_FLAG_WORKQ_MANAGER) { + if ((kqr->kqr_state & KQR_BOUND) == 0) { + kqr->kqr_state |= (KQR_BOUND | KQWQ_THMANAGER); + TAILQ_INIT(&kqr->kqr_suppressed); + kqr->kqr_thread = thread; + ut->uu_kqueue_bound = (struct kqueue *)kqwq; + ut->uu_kqueue_qos_index = KQWQ_QOS_MANAGER; + ut->uu_kqueue_flags = (KEVENT_FLAG_WORKQ | + KEVENT_FLAG_WORKQ_MANAGER); + } else { + assert(kqr->kqr_state & KQR_BOUND); + assert(thread == kqr->kqr_thread); + assert(ut->uu_kqueue_bound == (struct kqueue *)kqwq); + assert(ut->uu_kqueue_qos_index == KQWQ_QOS_MANAGER); + assert(ut->uu_kqueue_flags & KEVENT_FLAG_WORKQ_MANAGER); + } + return; } - if (kq->kq_count != 0) { + /* Just a normal one-queue servicing thread */ + assert(kqr->kqr_state & KQR_THREQUESTED); + assert(kqr->kqr_qos_index == qos_index); + + if ((kqr->kqr_state & KQR_BOUND) == 0) { + kqr->kqr_state |= KQR_BOUND; + TAILQ_INIT(&kqr->kqr_suppressed); + kqr->kqr_thread = thread; + + /* apply an ipc QoS override if one is needed */ + if (kqr->kqr_override_index) { + assert(kqr->kqr_qos_index); + assert(kqr->kqr_override_index > kqr->kqr_qos_index); + assert(thread_get_ipc_override(thread) == THREAD_QOS_UNSPECIFIED); + thread_add_ipc_override(thread, kqr->kqr_override_index); + } + + /* indicate that we are processing in the uthread */ + ut->uu_kqueue_bound = (struct kqueue *)kqwq; + ut->uu_kqueue_qos_index = qos_index; + ut->uu_kqueue_flags = flags; + } else { /* - * there is something queued - but it might be a - * KN_STAYQUEUED knote, which may or may not have - * any events pending. So, we have to walk the - * list of knotes to see, and peek at the stay- - * queued ones to be really sure. + * probably syncronously bound AND post-request bound + * this logic can go away when we get rid of post-request bind */ - while ((kn = (struct knote *)TAILQ_FIRST(&kq->kq_head)) != NULL) { - if ((kn->kn_status & KN_STAYQUEUED) == 0) { - retnum = 1; - goto out; - } + assert(kqr->kqr_state & KQR_BOUND); + assert(thread == kqr->kqr_thread); + assert(ut->uu_kqueue_bound == (struct kqueue *)kqwq); + assert(ut->uu_kqueue_qos_index == qos_index); + assert((ut->uu_kqueue_flags & flags) == flags); + } +} - TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); - TAILQ_INSERT_TAIL(&inprocessq, kn, kn_tqe); +static void +kqworkloop_update_override( + struct kqworkloop *kqwl, + kq_index_t qos_index, + kq_index_t override_index, + uint32_t flags) +{ + struct kqrequest *kqr = &kqwl->kqwl_request; - if (kqlock2knoteuse(kq, kn)) { - unsigned peek; + kqwl_req_lock(kqwl); - peek = kn->kn_fop->f_peek(kn); - if (knoteuse2kqlock(kq, kn)) { - if (peek > 0) { - retnum = 1; - goto out; - } - } else { - retnum = 0; - } - } + /* Do not override on attached threads */ + if (kqr->kqr_state & KQR_BOUND) { + assert(kqr->kqr_thread); + + if (kqwl->kqwl_kqueue.kq_state & KQ_NO_WQ_THREAD) { + kqwl_req_unlock(kqwl); + assert(!is_workqueue_thread(kqr->kqr_thread)); + return; } } -out: - /* Return knotes to active queue */ - while ((kn = TAILQ_FIRST(&inprocessq)) != NULL) { - TAILQ_REMOVE(&inprocessq, kn, kn_tqe); - kn->kn_tq = &kq->kq_head; - TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); + /* Update sync ipc counts on kqr for suppressed knotes */ + if (flags & KQWL_UO_UPDATE_SUPPRESS_SYNC_COUNTERS) { + kqworkloop_update_suppress_sync_count(kqr, flags); } - kqueue_end_processing(kq); - kqunlock(kq); - return (retnum); + if ((flags & KQWL_UO_UPDATE_OVERRIDE_LAZY) == 0) { + kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_WAKEUP_OVERRIDE, + MAX(qos_index, override_index)); + } + kqwl_req_unlock(kqwl); } -/* - * kqueue_close - - */ -/*ARGSUSED*/ -static int -kqueue_close(struct fileglob *fg, __unused vfs_context_t ctx) +static void +kqworkloop_update_suppress_sync_count( + struct kqrequest *kqr, + uint32_t flags) { - struct kqueue *kq = (struct kqueue *)fg->fg_data; + if (flags & KQWL_UO_NEW_OVERRIDE_IS_SYNC_UI) { + kqr->kqr_sync_suppress_count++; + } - kqueue_dealloc(kq); - fg->fg_data = NULL; - return (0); + if (flags & KQWL_UO_OLD_OVERRIDE_IS_SYNC_UI) { + assert(kqr->kqr_sync_suppress_count > 0); + kqr->kqr_sync_suppress_count--; + } } -/*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. + * kqworkloop_unbind_thread - Unbind the servicer thread of a workloop kqueue + * + * It will end the processing phase in case it was still processing: + * + * We may have to request a new thread for not KQ_NO_WQ_THREAD workloop. + * This can happen if : + * - there were active events at or above our QoS we never got to (count > 0) + * - we pended waitq hook callouts during processing + * - we pended wakeups while processing (or unsuppressing) + * + * Called with kqueue lock held. */ -static int -kqueue_kqfilter(__unused struct fileproc *fp, struct knote *kn, __unused vfs_context_t ctx) + +static void +kqworkloop_unbind_thread( + struct kqworkloop *kqwl, + thread_t thread, + __unused unsigned int flags) { - struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; - struct kqueue *parentkq = kn->kn_kq; + struct kqueue *kq = &kqwl->kqwl_kqueue; + struct kqrequest *kqr = &kqwl->kqwl_request; - if (parentkq == kq || - kn->kn_filter != EVFILT_READ) - return (1); + kqlock_held(kq); + + assert((kq->kq_state & KQ_PROCESSING) == 0); + if (kq->kq_state & KQ_PROCESSING) { + return; + } /* - * 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. + * 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. */ + kq->kq_state |= KQ_PROCESSING; + kqworkloop_acknowledge_events(kqwl, TRUE); + kq->kq_state &= ~KQ_PROCESSING; - kqlock(parentkq); - if (parentkq->kq_level > 0 && - parentkq->kq_level < kq->kq_level) - { - kqunlock(parentkq); - return (1); + kqwl_req_lock(kqwl); + + /* deal with extraneous unbinds in release kernels */ + assert((kqr->kqr_state & (KQR_BOUND | KQR_PROCESSING)) == KQR_BOUND); + if ((kqr->kqr_state & (KQR_BOUND | KQR_PROCESSING)) != KQR_BOUND) { + kqwl_req_unlock(kqwl); + return; + } + + assert(thread == current_thread()); + assert(kqr->kqr_thread == thread); + if (kqr->kqr_thread != thread) { + kqwl_req_unlock(kqwl); + return; + } + + struct uthread *ut = get_bsdthread_info(thread); + kq_index_t old_qos_index = ut->uu_kqueue_qos_index; + boolean_t ipc_override_is_sync = ut->uu_kqueue_override_is_sync; + ut->uu_kqueue_bound = NULL; + ut->uu_kqueue_qos_index = 0; + ut->uu_kqueue_override_is_sync = 0; + ut->uu_kqueue_flags = 0; + + /* unbind the servicer thread, drop overrides */ + kqr->kqr_thread = NULL; + kqr->kqr_state &= ~(KQR_BOUND | KQR_THREQUESTED | KQR_R2K_NOTIF_ARMED); + kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_RECOMPUTE_WAKEUP_QOS, 0); + + kqwl_req_unlock(kqwl); + + /* + * Drop the override on the current thread last, after the call to + * kqworkloop_update_threads_qos above. + */ + if (old_qos_index) { + thread_drop_ipc_override(thread); + } + if (ipc_override_is_sync) { + thread_drop_sync_ipc_override(thread); + } +} + +/* called with the kqworkq lock held */ +static void +kqworkq_unbind_thread( + struct kqworkq *kqwq, + kq_index_t qos_index, + thread_t thread, + __unused unsigned int flags) +{ + struct kqrequest *kqr = kqworkq_get_request(kqwq, qos_index); + kq_index_t override_index = 0; + + /* request lock must be held */ + kqwq_req_held(kqwq); + + assert(thread == current_thread()); + + if ((kqr->kqr_state & KQR_BOUND) == 0) { + assert(kqr->kqr_state & KQR_BOUND); + return; + } + + assert(kqr->kqr_thread == thread); + assert(TAILQ_EMPTY(&kqr->kqr_suppressed)); + + /* + * If there is an override, drop it from the current thread + * and then we are free to recompute (a potentially lower) + * minimum override to apply to the next thread request. + */ + if (kqr->kqr_override_index) { + struct kqtailq *base_queue = kqueue_get_base_queue(&kqwq->kqwq_kqueue, qos_index); + struct kqtailq *queue = kqueue_get_high_queue(&kqwq->kqwq_kqueue, qos_index); + + /* if not bound to a manager thread, drop the current ipc override */ + if ((kqr->kqr_state & KQWQ_THMANAGER) == 0) { + thread_drop_ipc_override(thread); + } + + /* recompute the new override */ + do { + if (!TAILQ_EMPTY(queue)) { + override_index = queue - base_queue + qos_index; + break; + } + } while (queue-- > base_queue); + } + + /* Mark it unbound */ + kqr->kqr_thread = NULL; + kqr->kqr_state &= ~(KQR_BOUND | KQR_THREQUESTED | KQWQ_THMANAGER); + + /* apply the new override */ + if (override_index > kqr->kqr_qos_index) { + kqr->kqr_override_index = override_index; } else { - /* set parent level appropriately */ - if (parentkq->kq_level == 0) - parentkq->kq_level = 2; - if (parentkq->kq_level < kq->kq_level + 1) - parentkq->kq_level = kq->kq_level + 1; - kqunlock(parentkq); + kqr->kqr_override_index = THREAD_QOS_UNSPECIFIED; + } +} + +struct kqrequest * +kqworkq_get_request(struct kqworkq *kqwq, kq_index_t qos_index) +{ + assert(qos_index < KQWQ_NQOS); + return &kqwq->kqwq_request[qos_index]; +} + +void +knote_adjust_qos(struct knote *kn, qos_t new_qos, qos_t new_override, kq_index_t sync_override_index) +{ + struct kqueue *kq = knote_get_kq(kn); + boolean_t override_is_sync = FALSE; + + if (kq->kq_state & (KQ_WORKQ | KQ_WORKLOOP)) { + kq_index_t new_qos_index; + kq_index_t new_override_index; + kq_index_t servicer_qos_index; + + new_qos_index = qos_index_from_qos(kn, new_qos, FALSE); + new_override_index = qos_index_from_qos(kn, new_override, TRUE); + + /* make sure the servicer qos acts as a floor */ + servicer_qos_index = qos_index_from_qos(kn, kn->kn_qos, FALSE); + if (servicer_qos_index > new_qos_index) + new_qos_index = servicer_qos_index; + if (servicer_qos_index > new_override_index) + new_override_index = servicer_qos_index; + if (sync_override_index >= new_override_index) { + new_override_index = sync_override_index; + override_is_sync = TRUE; + } - kn->kn_fop = &kqread_filtops; kqlock(kq); - KNOTE_ATTACH(&kq->kq_sel.si_note, kn); - /* indicate nesting in child, if needed */ - if (kq->kq_level == 0) - kq->kq_level = 1; + if (new_qos_index != knote_get_req_index(kn) || + new_override_index != knote_get_qos_override_index(kn) || + override_is_sync != kn->kn_qos_override_is_sync) { + if (kn->kn_status & KN_QUEUED) { + knote_dequeue(kn); + knote_set_qos_index(kn, new_qos_index); + knote_set_qos_override_index(kn, new_override_index, override_is_sync); + knote_enqueue(kn); + knote_wakeup(kn); + } else { + knote_set_qos_index(kn, new_qos_index); + knote_set_qos_override_index(kn, new_override_index, override_is_sync); + } + } kqunlock(kq); - return (0); } } -/* - * kqueue_drain - called when kq is closed - */ -/*ARGSUSED*/ -static int -kqueue_drain(struct fileproc *fp, __unused vfs_context_t ctx) +void +knote_adjust_sync_qos(struct knote *kn, kq_index_t sync_qos, boolean_t lock_kq) { - struct kqueue *kq = (struct kqueue *)fp->f_fglob->fg_data; - kqlock(kq); - kqueue_wakeup(kq, 1); - kqunlock(kq); - return (0); + struct kqueue *kq = knote_get_kq(kn); + kq_index_t old_sync_override; + kq_index_t qos_index = knote_get_qos_index(kn); + uint32_t flags = 0; + + /* Tracking only happens for UI qos */ + if (sync_qos != THREAD_QOS_USER_INTERACTIVE && + sync_qos != THREAD_QOS_UNSPECIFIED) { + return; + } + + if (lock_kq) + kqlock(kq); + + if (kq->kq_state & KQ_WORKLOOP) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + + old_sync_override = knote_get_sync_qos_override_index(kn); + if (old_sync_override != sync_qos) { + kn->kn_qos_sync_override = sync_qos; + + /* update sync ipc counters for suppressed knotes */ + if ((kn->kn_status & KN_SUPPRESSED) == KN_SUPPRESSED) { + flags = flags | KQWL_UO_UPDATE_SUPPRESS_SYNC_COUNTERS; + + /* Do not recalculate kqwl override, it would be done later */ + flags = flags | KQWL_UO_UPDATE_OVERRIDE_LAZY; + + if (sync_qos == THREAD_QOS_USER_INTERACTIVE) { + flags = flags | KQWL_UO_NEW_OVERRIDE_IS_SYNC_UI; + } + + if (old_sync_override == THREAD_QOS_USER_INTERACTIVE) { + flags = flags | KQWL_UO_OLD_OVERRIDE_IS_SYNC_UI; + } + + kqworkloop_update_override(kqwl, qos_index, sync_qos, + flags); + } + + } + } + if (lock_kq) + kqunlock(kq); } -/*ARGSUSED*/ -int -kqueue_stat(struct kqueue *kq, void *ub, int isstat64, proc_t p) +static void +knote_wakeup(struct knote *kn) { - kqlock(kq); - if (isstat64 != 0) { - struct stat64 *sb64 = (struct stat64 *)ub; + struct kqueue *kq = knote_get_kq(kn); + kq_index_t qos_index = knote_get_qos_index(kn); - bzero((void *)sb64, sizeof(*sb64)); - sb64->st_size = kq->kq_count; - if (kq->kq_state & KQ_KEV64) - sb64->st_blksize = sizeof(struct kevent64_s); - else - sb64->st_blksize = IS_64BIT_PROCESS(p) ? sizeof(struct user64_kevent) : sizeof(struct user32_kevent); - sb64->st_mode = S_IFIFO; + kqlock_held(kq); + + if (kq->kq_state & KQ_WORKQ) { + /* request a servicing thread */ + struct kqworkq *kqwq = (struct kqworkq *)kq; + + kqworkq_request_help(kqwq, qos_index); + + } else if (kq->kq_state & KQ_WORKLOOP) { + /* request a servicing thread */ + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + + if (kqworkloop_is_processing_on_current_thread(kqwl)) { + /* + * kqworkloop_end_processing() will perform the required QoS + * computations when it unsets the processing mode. + */ + return; + } + kqworkloop_request_help(kqwl, qos_index); } else { - struct stat *sb = (struct stat *)ub; + 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); + } - bzero((void *)sb, sizeof(*sb)); - sb->st_size = kq->kq_count; - if (kq->kq_state & KQ_KEV64) - sb->st_blksize = sizeof(struct kevent64_s); - else - sb->st_blksize = IS_64BIT_PROCESS(p) ? sizeof(struct user64_kevent) : sizeof(struct user32_kevent); - sb->st_mode = S_IFIFO; + /* wakeup other kqueues/select sets we're inside */ + KNOTE(&kqf->kqf_sel.si_note, 0); } - kqunlock(kq); - return (0); } /* * Called with the kqueue locked */ static void -kqueue_wakeup(struct kqueue *kq, int closed) +kqueue_interrupt(struct kqueue *kq) { - if ((kq->kq_state & (KQ_SLEEP | KQ_SEL)) != 0 || kq->kq_nprocess > 0) { + 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); - wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, KQ_EVENT, - (closed) ? THREAD_INTERRUPTED : THREAD_AWAKENED); + (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, QOS_INDEX_KQFILE); + (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); } } @@ -2534,7 +7766,7 @@ klist_init(struct klist *list) * * The object lock should also hold off pending * detach/drop operations. But we'll prevent it here - * too - just in case. + * too (by taking a use reference) - just in case. */ void knote(struct klist *list, long hint) @@ -2542,19 +7774,23 @@ knote(struct klist *list, long hint) struct knote *kn; SLIST_FOREACH(kn, list, kn_selnext) { - struct kqueue *kq = kn->kn_kq; + struct kqueue *kq = knote_get_kq(kn); kqlock(kq); - if (kqlock2knoteuse(kq, kn)) { + + assert(!knoteuse_needs_boost(kn, NULL)); + + /* If we can get a use reference - deliver event */ + if (kqlock2knoteuse(kq, kn, KNUSE_NONE)) { int result; /* call the event with only a use count */ - result = kn->kn_fop->f_event(kn, hint); + result = knote_fops(kn)->f_event(kn, hint); /* if its not going away and triggered */ - if (knoteuse2kqlock(kq, kn) && result) - knote_activate(kn, 1); - /* lock held again */ + if (knoteuse2kqlock(kq, kn, KNUSE_NONE) && result) + knote_activate(kn); + /* kq lock held */ } kqunlock(kq); } @@ -2583,6 +7819,55 @@ knote_detach(struct klist *list, struct knote *kn) 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); + int result; + + kqlock(kq); + + assert(!knoteuse_needs_boost(kn, NULL)); + + if ((kn->kn_status & KN_DROPPING) == 0) { + /* If EV_VANISH supported - prepare to deliver one */ + if (kn->kn_status & KN_REQVANISH) { + kn->kn_status |= KN_VANISHED; + knote_activate(kn); + + } else if (kqlock2knoteuse(kq, kn, KNUSE_NONE)) { + /* call the event with only a use count */ + result = knote_fops(kn)->f_event(kn, NOTE_REVOKE); + + /* if its not going away and triggered */ + if (knoteuse2kqlock(kq, kn, KNUSE_NONE) && result) + knote_activate(kn); + /* lock held again */ + } + } + kqunlock(kq); + } +} + /* * 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 @@ -2590,18 +7875,19 @@ knote_detach(struct klist *list, struct knote *kn) * we permanently enqueue them here. * * kqueue and knote references are held by caller. + * waitq locked by caller. * * caller provides the wait queue link structure. */ int -knote_link_wait_queue(struct knote *kn, struct wait_queue *wq, wait_queue_link_t wql) +knote_link_waitq(struct knote *kn, struct waitq *wq, uint64_t *reserved_link) { - struct kqueue *kq = kn->kn_kq; + struct kqueue *kq = knote_get_kq(kn); kern_return_t kr; - kr = wait_queue_link_noalloc(wq, kq->kq_wqs, wql); + kr = waitq_link(wq, &kq->kq_wqs, WAITQ_ALREADY_LOCKED, reserved_link); if (kr == KERN_SUCCESS) { - knote_markstayqueued(kn); + knote_markstayactive(kn); return (0); } else { return (EINVAL); @@ -2618,16 +7904,13 @@ knote_link_wait_queue(struct knote *kn, struct wait_queue *wq, wait_queue_link_t * On success, caller is responsible for the link structure */ int -knote_unlink_wait_queue(struct knote *kn, struct wait_queue *wq, wait_queue_link_t *wqlp) +knote_unlink_waitq(struct knote *kn, struct waitq *wq) { - struct kqueue *kq = kn->kn_kq; + struct kqueue *kq = knote_get_kq(kn); kern_return_t kr; - kr = wait_queue_unlink_nofree(wq, kq->kq_wqs, wqlp); - kqlock(kq); - kn->kn_status &= ~KN_STAYQUEUED; - knote_dequeue(kn); - kqunlock(kq); + kr = waitq_unlink(wq, &kq->kq_wqs); + knote_clearstayactive(kn); return ((kr != KERN_SUCCESS) ? EINVAL : 0); } @@ -2641,73 +7924,214 @@ knote_unlink_wait_queue(struct knote *kn, struct wait_queue *wq, wait_queue_link * It returns the same way, but may drop it temporarily. */ void -knote_fdclose(struct proc *p, int fd) +knote_fdclose(struct proc *p, int fd, int force) { - struct filedesc *fdp = p->p_fd; struct klist *list; struct knote *kn; - list = &fdp->fd_knlist[fd]; - while ((kn = SLIST_FIRST(list)) != NULL) { - struct kqueue *kq = kn->kn_kq; +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); - kqlock(kq); + /* + * If the knote supports EV_VANISHED delivery, + * transition it to vanished mode (or skip over + * it if already vanished). + */ + if (!force && (kn->kn_status & KN_REQVANISH)) { + + if ((kn->kn_status & KN_VANISHED) == 0) { + proc_fdunlock(p); + + assert(!knoteuse_needs_boost(kn, NULL)); + + /* get detach reference (also marks vanished) */ + if (kqlock2knotedetach(kq, kn, KNUSE_NONE)) { + /* detach knote and drop fp use reference */ + knote_fops(kn)->f_detach(kn); + if (knote_fops(kn)->f_isfd) + fp_drop(p, kn->kn_id, kn->kn_fp, 0); + + /* activate it if it's still in existence */ + if (knoteuse2kqlock(kq, kn, KNUSE_NONE)) { + knote_activate(kn); + } + kqunlock(kq); + } + proc_fdlock(p); + goto restart; + } else { + kqunlock(kq); + continue; + } + } + proc_fdunlock(p); /* - * Convert the lock to a drop ref. + * Convert the kq lock to a drop ref. * If we get it, go ahead and drop it. - * Otherwise, we waited for it to - * be dropped by the other guy, so - * it is safe to move on in the list. + * Otherwise, we waited for the blocking + * condition to complete. Either way, + * we dropped the fdlock so start over. */ if (kqlock2knotedrop(kq, kn)) { - kn->kn_fop->f_detach(kn); knote_drop(kn, p); } 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)]; + } - /* the fd tables may have changed - start over */ - list = &fdp->fd_knlist[fd]; + /* + * 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; } -/* proc_fdlock held on entry (and exit) */ +/* + * 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 -knote_fdpattach(struct knote *kn, struct filedesc *fdp, struct proc *p) +kq_add_knote(struct kqueue *kq, struct knote *kn, + struct kevent_internal_s *kev, + struct proc *p, int *knoteuse_flags) { + 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, kev, 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; + } - if (! kn->kn_fop->f_isfd) { - if (fdp->fd_knhashmask == 0) - fdp->fd_knhash = hashinit(CONFIG_KN_HASHSIZE, M_KQUEUE, - &fdp->fd_knhashmask); list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; + 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) - return (EINVAL); - + || 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 *))) - return (EINVAL); + 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) - return (ENOMEM); + if (list == NULL) { + ret = ENOMEM; + goto out_locked; + } bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, fdp->fd_knlistsize * sizeof(struct klist *)); @@ -2718,109 +8142,413 @@ knote_fdpattach(struct knote *kn, struct filedesc *fdp, struct proc *p) 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; + } - SLIST_INSERT_HEAD(list, kn, kn_link); - return (0); -} +out_locked: + if (ret == 0 && knoteuse_needs_boost(kn, kev)) { + set_thread_rwlock_boost(); + *knoteuse_flags = KNUSE_BOOST; + } else { + *knoteuse_flags = KNUSE_NONE; + } + if (is_fd) + proc_fdunlock(p); + else + knhash_unlock(p); + return ret; +} /* - * should be called at spl == 0, since we don't want to hold spl - * while calling fdrop and free. + * kq_remove_knote - remove a knote from the fd table for process + * and copy kn_status an kq_state while holding kqlock and + * fd table locks. + * + * 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 -knote_drop(struct knote *kn, __unused struct proc *ctxp) +kq_remove_knote(struct kqueue *kq, struct knote *kn, struct proc *p, + kn_status_t *kn_status, uint16_t *kq_state) { - struct kqueue *kq = kn->kn_kq; - struct proc *p = kq->kq_p; struct filedesc *fdp = p->p_fd; - struct klist *list; - int needswakeup; + struct klist *list = NULL; + bool is_fd; - proc_fdlock(p); - if (kn->kn_fop->f_isfd) - list = &fdp->fd_knlist[kn->kn_id]; + is_fd = knote_fops(kn)->f_isfd; + + if (is_fd) + proc_fdlock(p); else - list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; + 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); - knote_dequeue(kn); - needswakeup = (kn->kn_status & KN_USEWAIT); + *kn_status = kn->kn_status; + *kq_state = kq->kq_state; kqunlock(kq); - proc_fdunlock(p); - if (needswakeup) - wait_queue_wakeup_all((wait_queue_t)kq->kq_wqs, &kn->kn_status, - THREAD_AWAKENED); + if (is_fd) + proc_fdunlock(p); + else + knhash_unlock(p); +} + +/* + * 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 unlocked and holding a + * "drop reference" on the knote in question. + * This reference is most often aquired thru a call + * to kqlock2knotedrop(). But it can also be acquired + * through stealing a drop reference via a call to + * knoteuse2knotedrop() or during the initial attach + * of the knote. + * + * The knote may have already been detached from + * (or not yet attached to) its source object. + */ +static void +knote_drop(struct knote *kn, __unused struct proc *ctxp) +{ + struct kqueue *kq = knote_get_kq(kn); + struct proc *p = kq->kq_p; + kn_status_t kn_status; + uint16_t kq_state; + + /* If we are attached, disconnect from the source first */ + if (kn->kn_status & KN_ATTACHED) { + knote_fops(kn)->f_detach(kn); + } + + /* Remove the source from the appropriate hash */ + kq_remove_knote(kq, kn, p, &kn_status, &kq_state); + + /* + * If a kqueue_dealloc is happening in parallel for the kq + * pointed by the knote the kq could be aready deallocated + * at this point. + * Do not access the kq after the kq_remove_knote if it is + * not a KQ_DYNAMIC. + */ + + /* determine if anyone needs to know about the drop */ + assert((kn_status & (KN_DROPPING | KN_SUPPRESSED | KN_QUEUED)) == KN_DROPPING); + + /* + * If KN_USEWAIT is set, some other thread was trying to drop the kn. + * Or it was in kqueue_dealloc, so the kqueue_dealloc did not happen + * because that thread was waiting on this wake, or it was a drop happening + * because of a kevent_register that takes a reference on the kq, and therefore + * the kq cannot be deallocated in parallel. + * + * It is safe to access kq->kq_wqs if needswakeup is set. + */ + if (kn_status & KN_USEWAIT) + waitq_wakeup64_all((struct waitq *)&kq->kq_wqs, + CAST_EVENT64_T(&kn->kn_status), + THREAD_RESTART, + WAITQ_ALL_PRIORITIES); + + 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); + + /* + * release reference on dynamic kq (and free if last). + * Will only be last if this is from fdfree, etc... + * because otherwise processing thread has reference. + */ + if (kq_state & KQ_DYNAMIC) + kqueue_release_last(p, kq); +} + +/* 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) { + /* Clear the sync qos on the knote */ + knote_adjust_sync_qos(kn, THREAD_QOS_UNSPECIFIED, FALSE); + + /* + * 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_fop->f_isfd) - fp_drop(p, kn->kn_id, kn->kn_fp, 0); + if (kn->kn_status & KN_SUPPRESSED) + return; - knote_free(kn); + knote_dequeue(kn); + kn->kn_status |= KN_SUPPRESSED; + suppressq = kqueue_get_suppressed_queue(kq, knote_get_qos_index(kn)); + TAILQ_INSERT_TAIL(suppressq, kn, kn_tqe); + + if ((kq->kq_state & KQ_WORKLOOP) && + knote_get_qos_override_index(kn) == THREAD_QOS_USER_INTERACTIVE && + kn->kn_qos_override_is_sync) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + /* update the sync qos override counter for suppressed knotes */ + kqworkloop_update_override(kqwl, knote_get_qos_index(kn), + knote_get_qos_override_index(kn), + (KQWL_UO_UPDATE_SUPPRESS_SYNC_COUNTERS | KQWL_UO_NEW_OVERRIDE_IS_SYNC_UI)); + } } /* called with kqueue lock held */ static void -knote_activate(struct knote *kn, int propagate) +knote_unsuppress(struct knote *kn) { - struct kqueue *kq = kn->kn_kq; + struct kqtailq *suppressq; + struct kqueue *kq = knote_get_kq(kn); - kn->kn_status |= KN_ACTIVE; - knote_enqueue(kn); - kqueue_wakeup(kq, 0); + kqlock_held(kq); + + if ((kn->kn_status & KN_SUPPRESSED) == 0) + return; + + /* Clear the sync qos on the knote */ + knote_adjust_sync_qos(kn, THREAD_QOS_UNSPECIFIED, FALSE); + + kn->kn_status &= ~KN_SUPPRESSED; + suppressq = kqueue_get_suppressed_queue(kq, knote_get_qos_index(kn)); + TAILQ_REMOVE(suppressq, kn, kn_tqe); + + /* udate in-use qos to equal requested qos */ + kn->kn_qos_index = kn->kn_req_index; - /* this is a real event: wake up the parent kq, too */ - if (propagate) - KNOTE(&kq->kq_sel.si_note, 0); + /* 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) && !(kq->kq_state & KQ_NO_WQ_THREAD) && + knote_get_qos_override_index(kn) == THREAD_QOS_USER_INTERACTIVE && + kn->kn_qos_override_is_sync) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + + /* update the sync qos override counter for suppressed knotes */ + kqworkloop_update_override(kqwl, knote_get_qos_index(kn), + knote_get_qos_override_index(kn), + (KQWL_UO_UPDATE_SUPPRESS_SYNC_COUNTERS | KQWL_UO_OLD_OVERRIDE_IS_SYNC_UI)); + } + + if (TAILQ_EMPTY(suppressq) && (kq->kq_state & KQ_WORKLOOP) && + !(kq->kq_state & KQ_NO_WQ_THREAD)) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + if (kqworkloop_is_processing_on_current_thread(kqwl)) { + /* + * kqworkloop_end_processing() will perform the required QoS + * computations when it unsets the processing mode. + */ + } else { + kqwl_req_lock(kqwl); + kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_RESET_WAKEUP_OVERRIDE, 0); + kqwl_req_unlock(kqwl); + } + } } /* called with kqueue lock held */ static void -knote_deactivate(struct knote *kn) +knote_update_sync_override_state(struct knote *kn) { - kn->kn_status &= ~KN_ACTIVE; - knote_dequeue(kn); + struct kqtailq *queue = knote_get_queue(kn); + struct kqueue *kq = knote_get_kq(kn); + + if (!(kq->kq_state & KQ_WORKLOOP) || + knote_get_queue_index(kn) != THREAD_QOS_USER_INTERACTIVE) + return; + + /* Update the sync ipc state on workloop */ + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + boolean_t sync_ipc_override = FALSE; + if (!TAILQ_EMPTY(queue)) { + struct knote *kn_head = TAILQ_FIRST(queue); + if (kn_head->kn_qos_override_is_sync) + sync_ipc_override = TRUE; + } + kqworkloop_update_sync_override_state(kqwl, sync_ipc_override); } /* called with kqueue lock held */ -static void +static int knote_enqueue(struct knote *kn) { - if ((kn->kn_status & (KN_QUEUED | KN_STAYQUEUED)) == KN_STAYQUEUED || - (kn->kn_status & (KN_QUEUED | KN_STAYQUEUED | KN_DISABLED)) == 0) { - struct kqtailq *tq = kn->kn_tq; - struct kqueue *kq = kn->kn_kq; - - TAILQ_INSERT_TAIL(tq, kn, kn_tqe); + 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); + /* insert at head for sync ipc waiters */ + if (kn->kn_qos_override_is_sync) { + TAILQ_INSERT_HEAD(queue, kn, kn_tqe); + } else { + TAILQ_INSERT_TAIL(queue, kn, kn_tqe); + } kn->kn_status |= KN_QUEUED; kq->kq_count++; + knote_update_sync_override_state(kn); + return 1; } + return ((kn->kn_status & KN_STAYACTIVE) != 0); } + /* called with kqueue lock held */ static void knote_dequeue(struct knote *kn) { - struct kqueue *kq = kn->kn_kq; + struct kqueue *kq = knote_get_kq(kn); + struct kqtailq *queue; - if ((kn->kn_status & (KN_QUEUED | KN_STAYQUEUED)) == KN_QUEUED) { - struct kqtailq *tq = kn->kn_tq; + kqlock_held(kq); - TAILQ_REMOVE(tq, kn, kn_tqe); - kn->kn_tq = &kq->kq_head; - kn->kn_status &= ~KN_QUEUED; - kq->kq_count--; - } + 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--; + knote_update_sync_override_state(kn); } void knote_init(void) { knote_zone = zinit(sizeof(struct knote), 8192*sizeof(struct knote), - 8192, "knote zone"); + 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(); @@ -2833,10 +8561,8 @@ knote_init(void) /* Initialize the timer filter lock */ lck_mtx_init(&_filt_timerlock, kq_lck_grp, kq_lck_attr); -#if VM_PRESSURE_EVENTS - /* Initialize the vm pressure list lock */ - vm_pressure_init(kq_lck_grp, kq_lck_attr); -#endif + /* Initialize the user filter lock */ + lck_spin_init(&_filt_userlock, kq_lck_grp, kq_lck_attr); #if CONFIG_MEMORYSTATUS /* Initialize the memorystatus list lock */ @@ -2845,10 +8571,19 @@ knote_init(void) } 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) { - return ((struct knote *)zalloc(knote_zone)); + struct knote *kn; + kn = ((struct knote *)zalloc(knote_zone)); + *kn = (struct knote) { .kn_qos_override = 0, .kn_qos_sync_override = 0, .kn_qos_override_is_sync = 0 }; + return kn; } static void @@ -2928,9 +8663,9 @@ SYSCTL_PROC(_net_systm_kevt, OID_AUTO, pcblist, kevt_pcblist, "S,xkevtpcb", ""); static lck_mtx_t * -event_getlock(struct socket *so, int locktype) +event_getlock(struct socket *so, int flags) { -#pragma unused(locktype) +#pragma unused(flags) struct kern_event_pcb *ev_pcb = (struct kern_event_pcb *)so->so_pcb; if (so->so_pcb != NULL) { @@ -2990,9 +8725,9 @@ event_unlock(struct socket *so, int refcount, void *lr) else lr_saved = lr; - if (refcount) + 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)); @@ -3006,7 +8741,7 @@ event_unlock(struct socket *so, int refcount, void *lr) } mutex_held = (&((struct kern_event_pcb *)so->so_pcb)->evp_mtx); - lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED); + 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; @@ -3025,7 +8760,7 @@ 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); + LCK_MTX_ASSERT(&(ev_pcb->evp_mtx), LCK_MTX_ASSERT_OWNED); so->so_pcb = NULL; @@ -3039,7 +8774,7 @@ event_sofreelastref(struct socket *so) so->so_event = sonullevent; lck_mtx_unlock(&(ev_pcb->evp_mtx)); - lck_mtx_assert(&(ev_pcb->evp_mtx), LCK_MTX_ASSERT_NOTOWNED); + 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--; @@ -3223,7 +8958,7 @@ kev_post_msg(struct kev_msg *event_msg) return (EMSGSIZE); } - m = m_get(M_DONTWAIT, MT_DATA); + m = m_get(M_WAIT, MT_DATA); if (m == 0) { OSIncrementAtomic64((SInt64 *)&kevtstat.kes_nomem); return (ENOMEM); @@ -3281,7 +9016,7 @@ kev_post_msg(struct kev_msg *event_msg) } } - m2 = m_copym(m, 0, m->m_len, M_NOWAIT); + m2 = m_copym(m, 0, m->m_len, M_WAIT); if (m2 == 0) { OSIncrementAtomic64((SInt64 *)&kevtstat.kes_nomem); m_free(m); @@ -3295,7 +9030,7 @@ kev_post_msg(struct kev_msg *event_msg) * unsafe to use "m2" */ so_inc_recv_data_stat(ev_pcb->evp_socket, - 1, m->m_len, SO_TC_BE); + 1, m->m_len, MBUF_TC_BE); sorwakeup(ev_pcb->evp_socket); OSIncrementAtomic64((SInt64 *)&kevtstat.kes_posted); @@ -3495,25 +9230,510 @@ fill_kqueueinfo(struct kqueue *kq, struct kqueue_info * kinfo) st = &kinfo->kq_stat; st->vst_size = kq->kq_count; - if (kq->kq_state & KQ_KEV64) + 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; - if (kq->kq_state & KQ_SEL) - kinfo->kq_state |= PROC_KQUEUE_SELECT; - if (kq->kq_state & KQ_SLEEP) - kinfo->kq_state |= PROC_KQUEUE_SLEEP; + st->vst_ino = (kq->kq_state & KQ_DYNAMIC) ? + ((struct kqworkloop *)kq)->kqwl_dynamicid : 0; + + /* 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; return (0); } +static int +fill_kqueue_dyninfo(struct kqueue *kq, struct kqueue_dyninfo *kqdi) +{ + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + struct kqrequest *kqr = &kqwl->kqwl_request; + int err; + + if ((kq->kq_state & KQ_WORKLOOP) == 0) { + return EINVAL; + } + + if ((err = fill_kqueueinfo(kq, &kqdi->kqdi_info))) { + return err; + } + + kqwl_req_lock(kqwl); + + if (kqr->kqr_thread) { + kqdi->kqdi_servicer = thread_tid(kqr->kqr_thread); + } + + if (kqwl->kqwl_owner == WL_OWNER_SUSPENDED) { + kqdi->kqdi_owner = ~0ull; + } else { + 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 = kqr->kqr_dsync_waiters_qos; + + kqwl_req_unlock(kqwl); + + return 0; +} + + +void +knote_markstayactive(struct knote *kn) +{ + struct kqueue *kq = knote_get_kq(kn); + + kqlock(kq); + kn->kn_status |= KN_STAYACTIVE; + + /* + * 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); + + /* handle all stayactive knotes on the (appropriate) manager */ + if (kq->kq_state & KQ_WORKQ) { + knote_set_qos_index(kn, KQWQ_QOS_MANAGER); + } else if (kq->kq_state & KQ_WORKLOOP) { + struct kqworkloop *kqwl = (struct kqworkloop *)kq; + kqwl_req_lock(kqwl); + assert(kn->kn_req_index && kn->kn_req_index < THREAD_QOS_LAST); + kqworkloop_update_threads_qos(kqwl, KQWL_UTQ_UPDATE_STAYACTIVE_QOS, + kn->kn_req_index); + kqwl_req_unlock(kqwl); + knote_set_qos_index(kn, KQWL_BUCKET_STAYACTIVE); + } + + knote_activate(kn); + kqunlock(kq); +} + +void +knote_clearstayactive(struct knote *kn) +{ + kqlock(knote_get_kq(kn)); + kn->kn_status &= ~KN_STAYACTIVE; + knote_deactivate(kn); + kqunlock(knote_get_kq(kn)); +} + +static unsigned long +kevent_extinfo_emit(struct kqueue *kq, struct knote *kn, struct kevent_extinfo *buf, + unsigned long buflen, unsigned long nknotes) +{ + 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; +} + +int +kevent_copyout_proc_dynkqids(void *proc, user_addr_t ubuf, uint32_t ubufsize, + int32_t *nkqueues_out) +{ + 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; + + assert(p != NULL); + + if (ubuf == USER_ADDR_NULL && ubufsize != 0) { + err = EINVAL; + goto out; + } + + buflen = min(ubuflen, PROC_PIDDYNKQUEUES_MAX); + + if (ubuflen != 0) { + if (os_mul_overflow(sizeof(kqueue_id_t), buflen, &bufsize)) { + err = ERANGE; + goto out; + } + kq_ids = kalloc(bufsize); + assert(kq_ids != NULL); + } + + 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) { + /* 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(ubuflen, nkqueues), ©size)) { + err = ERANGE; + goto out; + } + + assert(ubufsize >= copysize); + err = copyout(kq_ids, ubuf, copysize); + } + +out: + if (kq_ids) { + kfree(kq_ids, bufsize); + } + + if (!err) { + *nkqueues_out = (int)min(nkqueues, PROC_PIDDYNKQUEUES_MAX); + } + return err; +} + +int +kevent_copyout_dynkqinfo(void *proc, kqueue_id_t kq_id, user_addr_t ubuf, + uint32_t ubufsize, int32_t *size_out) +{ + proc_t p = (proc_t)proc; + struct kqueue *kq; + int err = 0; + struct kqueue_dyninfo kqdi = { }; + + assert(p != NULL); + + if (ubufsize < sizeof(struct kqueue_info)) { + return ENOBUFS; + } + + kqhash_lock(p); + kq = kqueue_hash_lookup(p, kq_id); + if (!kq) { + kqhash_unlock(p); + return ESRCH; + } + kqueue_retain(kq); + kqhash_unlock(p); + + /* + * 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 +kevent_copyout_dynkqextinfo(void *proc, kqueue_id_t kq_id, user_addr_t ubuf, + uint32_t ubufsize, int32_t *nknotes_out) +{ + proc_t p = (proc_t)proc; + struct kqueue *kq; + int err; + + assert(p != NULL); + + 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 +pid_kqueue_extinfo(proc_t p, struct kqueue *kq, user_addr_t ubuf, + uint32_t bufsize, int32_t *retval) +{ + 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); + + kqext = kalloc(buflen * sizeof(struct kevent_extinfo)); + if (kqext == NULL) { + err = ENOMEM; + goto out; + } + bzero(kqext, buflen * sizeof(struct kevent_extinfo)); + + 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); + + 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); + } + } + + 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; + } + + if (!err) { + *retval = min(nknotes, PROC_PIDFDKQUEUE_KNOTES_MAX); + } + return err; +} + +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++; + } + + return nknotes; +} + +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; +} + +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); + + if (buflen > 0) { + assert(buf != NULL); + } + + 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); + + return (int)nuptrs; +} + +static void +kevent_redrive_proc_thread_request(proc_t p) +{ + __assert_only int ret; + ret = (*pthread_functions->workq_threadreq)(p, NULL, WORKQ_THREADREQ_REDRIVE, 0, 0); + assert(ret == 0 || ret == ECANCELED); +} + +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_kqueue_bound != NULL) { + if (ut->uu_kqueue_flags & KEVENT_FLAG_WORKLOOP) { + ast_flags64 |= R2K_WORKLOOP_PENDING_EVENTS; + } else if (ut->uu_kqueue_flags & KEVENT_FLAG_WORKQ) { + ast_flags64 |= R2K_WORKQ_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); + } +} void -knote_markstayqueued(struct knote *kn) +kevent_ast(thread_t thread, uint16_t bits) +{ + proc_t p = current_proc(); + + if (bits & AST_KEVENT_REDRIVE_THREADREQ) { + kevent_redrive_proc_thread_request(p); + } + if (bits & AST_KEVENT_RETURN_TO_KERNEL) { + kevent_set_return_to_kernel_user_tsd(p, thread); + } +} + +#if DEVELOPMENT || DEBUG + +#define KEVENT_SYSCTL_BOUND_ID 1 + +static int +kevent_sysctl SYSCTL_HANDLER_ARGS { - kqlock(kn->kn_kq); - kn->kn_status |= KN_STAYQUEUED; - knote_enqueue(kn); - kqunlock(kn->kn_kq); +#pragma unused(oidp, arg2) + uintptr_t type = (uintptr_t)arg1; + uint64_t bound_id = 0; + struct uthread *ut; + struct kqueue *kq; + + if (type != KEVENT_SYSCTL_BOUND_ID) { + return EINVAL; + } + + if (req->newptr) { + return EINVAL; + } + + ut = get_bsdthread_info(current_thread()); + if (!ut) { + return EFAULT; + } + + kq = ut->uu_kqueue_bound; + if (kq) { + if (kq->kq_state & KQ_WORKLOOP) { + bound_id = ((struct kqworkloop *)kq)->kqwl_dynamicid; + } else if (kq->kq_state & KQ_WORKQ) { + bound_id = -1; + } + } + + 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 */