diff options
Diffstat (limited to 'sys/kern/kern_event.c')
| -rw-r--r-- | sys/kern/kern_event.c | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c index 828b2ffa06c..b84a674e38b 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_event.c,v 1.120 2020/01/13 13:57:19 visa Exp $ */ +/* $OpenBSD: kern_event.c,v 1.121 2020/01/18 08:59:48 visa Exp $ */ /*- * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> @@ -465,6 +465,27 @@ seltrue_kqfilter(dev_t dev, struct knote *kn) return (0); } +static int +filt_dead(struct knote *kn, long hint) +{ + kn->kn_flags |= (EV_EOF | EV_ONESHOT); + kn->kn_data = 0; + return (1); +} + +static void +filt_deaddetach(struct knote *kn) +{ + /* Nothing to do */ +} + +static const struct filterops dead_filtops = { + .f_isfd = 1, + .f_attach = NULL, + .f_detach = filt_deaddetach, + .f_event = filt_dead, +}; + int sys_kqueue(struct proc *p, void *v, register_t *retval) { @@ -1315,8 +1336,18 @@ klist_invalidate(struct klist *list) { struct knote *kn; - SLIST_FOREACH(kn, list, kn_selnext) { - kn->kn_status |= KN_DETACHED; - kn->kn_flags |= EV_EOF | EV_ONESHOT; + /* + * NET_LOCK() must not be held because it can block another thread + * in f_event with a knote acquired. + */ + NET_ASSERT_UNLOCKED(); + + while ((kn = SLIST_FIRST(list)) != NULL) { + if (knote_acquire(kn) == 0) + continue; + kn->kn_fop->f_detach(kn); + kn->kn_fop = &dead_filtops; + knote_activate(kn); + knote_release(kn); } } |