+ 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) {
+ /*
+ * <rdar://problem/31634014> 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());
projects / apple / xnu.git / blobdiff