Index: uipc_sem.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/uipc_sem.c,v
retrieving revision 1.19
diff -u -r1.19 uipc_sem.c
--- uipc_sem.c	4 May 2005 10:39:13 -0000	1.19
+++ uipc_sem.c	4 Jun 2005 01:30:37 -0000
@@ -915,6 +915,10 @@
 
 	mtx_lock(&sem_lock);
 	count = sem_count_proc(p1);
+	if (count == 0) {
+		mtx_unlock(&sem_lock);
+		return;
+	}
 race_lost:
 	mtx_assert(&sem_lock, MA_OWNED);
 	mtx_unlock(&sem_lock);