svn commit: r254072 - in head/sys: kern sys
John Baldwin
jhb at FreeBSD.org
Wed Aug 7 19:56:36 UTC 2013
Author: jhb
Date: Wed Aug 7 19:56:35 2013
New Revision: 254072
URL: http://svnweb.freebsd.org/changeset/base/254072
Log:
Don't emit a spurious EVFILT_PROC event with no fflags set on process exit
if NOTE_EXIT is not being monitored. The rationale is that a listener
should only get an event for exit() if they registered interest via
NOTE_EXIT. This matches the behavior on OS X.
- Don't save the exit status on process exit unless NOTE_EXIT is being
monitored.
- Add an internal EV_DROP flag that requests kqueue_scan() to free the
knote without signalling it to userland and use this when a process
exits but the fflags in the knote is zero.
Reviewed by: jmg
MFC after: 1 month
Modified:
head/sys/kern/kern_event.c
head/sys/sys/event.h
Modified: head/sys/kern/kern_event.c
==============================================================================
--- head/sys/kern/kern_event.c Wed Aug 7 19:53:41 2013 (r254071)
+++ head/sys/kern/kern_event.c Wed Aug 7 19:56:35 2013 (r254072)
@@ -431,8 +431,11 @@ filt_proc(struct knote *kn, long hint)
if (!(kn->kn_status & KN_DETACHED))
knlist_remove_inevent(&p->p_klist, kn);
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
- kn->kn_data = p->p_xstat;
kn->kn_ptr.p_proc = NULL;
+ if (kn->kn_fflags & NOTE_EXIT)
+ kn->kn_data = p->p_xstat;
+ if (kn->kn_fflags == 0)
+ kn->kn_flags |= EV_DROP;
return (1);
}
@@ -1410,7 +1413,21 @@ retry:
KASSERT((kn->kn_status & KN_INFLUX) == 0,
("KN_INFLUX set when not suppose to be"));
- if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) {
+ if ((kn->kn_flags & EV_DROP) == EV_DROP) {
+ kn->kn_status &= ~KN_QUEUED;
+ kn->kn_status |= KN_INFLUX;
+ kq->kq_count--;
+ KQ_UNLOCK(kq);
+ /*
+ * We don't need to lock the list since we've marked
+ * it _INFLUX.
+ */
+ if (!(kn->kn_status & KN_DETACHED))
+ kn->kn_fop->f_detach(kn);
+ knote_drop(kn, td);
+ KQ_LOCK(kq);
+ continue;
+ } else if ((kn->kn_flags & EV_ONESHOT) == EV_ONESHOT) {
kn->kn_status &= ~KN_QUEUED;
kn->kn_status |= KN_INFLUX;
kq->kq_count--;
Modified: head/sys/sys/event.h
==============================================================================
--- head/sys/sys/event.h Wed Aug 7 19:53:41 2013 (r254071)
+++ head/sys/sys/event.h Wed Aug 7 19:56:35 2013 (r254072)
@@ -76,6 +76,7 @@ struct kevent {
#define EV_DISPATCH 0x0080 /* disable event after reporting */
#define EV_SYSFLAGS 0xF000 /* reserved by system */
+#define EV_DROP 0x1000 /* note should be dropped */
#define EV_FLAG1 0x2000 /* filter-specific flag */
/* returned values */
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