Fix msleep.

Since mutexes mess around with spl levels, and the sched-lock isn't a
mutex, we need to make sure to fix the IPL when msleep does the locking.


ok art.

1 files changed, 4 insertions, 2 deletions

diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 209883c59b4..d1dc798669e 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.82 2007/11/28 20:07:36 oga Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.83 2007/11/30 16:44:44 oga Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*
@@ -144,7 +144,7 @@ int
 msleep(void *ident, struct mutex *mtx,  int priority, const char *wmesg, int timo)
 {
 	struct sleep_state sls;
-	int error, error1;
+	int error, error1, spl;
 
 	sleep_setup(&sls, ident, priority, wmesg);
 	sleep_setup_timeout(&sls, timo);
@@ -155,6 +155,7 @@ msleep(void *ident, struct mutex *mtx,  int priority, const char *wmesg, int tim
 		 * unblock splsched. This can be made a bit more 
 		 * correct when the sched_lock is a mutex.
 		 */
+		spl = MUTEX_OLDIPL(mtx);
 		MUTEX_OLDIPL(mtx) = splsched();
 		mtx_leave(mtx);
 	}
@@ -166,6 +167,7 @@ msleep(void *ident, struct mutex *mtx,  int priority, const char *wmesg, int tim
 	if (mtx && (priority & PNORELOCK) == 0)
 		mtx_enter(mtx);
 
+	MUTEX_OLDIPL(mtx) = spl; /* put the ipl back else it breaks things */
 	/* Signal errors are higher priority than timeouts. */
 	if (error == 0 && error1 != 0)
 		error = error1;