Defer freeing a kevent list until after dropping kqueue locks.

LOR:		185
Submitted by:	Matthew Fleming @ Isilon
MFC after:	1 week

1 files changed, 6 insertions, 4 deletions

diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c
index cb418fb..5df669d 100644
--- a/sys/kern/kern_event.c
+++ b/sys/kern/kern_event.c
@@ -1218,7 +1218,7 @@ static int
 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
 	int waitok)
 {
-	struct klist *list, *tmp_knhash;
+	struct klist *list, *tmp_knhash, *to_free;
 	u_long tmp_knhashmask;
 	int size;
 	int fd;
@@ -1226,6 +1226,7 @@ kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
 
 	KQ_NOTOWNED(kq);
 
+	to_free = NULL;
 	if (fops->f_isfd) {
 		fd = ident;
 		if (kq->kq_knlistsize <= fd) {
@@ -1237,13 +1238,13 @@ kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
 				return ENOMEM;
 			KQ_LOCK(kq);
 			if (kq->kq_knlistsize > fd) {
-				free(list, M_KQUEUE);
+				to_free = list;
 				list = NULL;
 			} else {
 				if (kq->kq_knlist != NULL) {
 					bcopy(kq->kq_knlist, list,
 					    kq->kq_knlistsize * sizeof(*list));
-					free(kq->kq_knlist, M_KQUEUE);
+					to_free = kq->kq_knlist;
 					kq->kq_knlist = NULL;
 				}
 				bzero((caddr_t)list +
@@ -1265,11 +1266,12 @@ kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
 				kq->kq_knhash = tmp_knhash;
 				kq->kq_knhashmask = tmp_knhashmask;
 			} else {
-				free(tmp_knhash, M_KQUEUE);
+				to_free = tmp_knhash;
 			}
 			KQ_UNLOCK(kq);
 		}
 	}
+	free(to_free, M_KQUEUE);
 
 	KQ_NOTOWNED(kq);
 	return 0;