From: Matthew Dillon <dillon@dragonflybsd.org>
Date: Mon, 15 Jan 2007 19:08:10 +0000 (+0000)
Subject: cputimer_intr_reload() - prevent a negatively indexed or too-small a reload
X-Git-Tag: v2.0.1~3676
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/307ae84dfc892ef0e7d9caebcb1f73831c21bb5c

cputimer_intr_reload() - prevent a negatively indexed or too-small a reload
value from loading the kqueue timer with an illegal value.
---

diff --git a/sys/platform/vkernel/platform/kqueue.c b/sys/platform/vkernel/platform/kqueue.c
index f753ab8727..f145c1fef2 100644
--- a/sys/platform/vkernel/platform/kqueue.c
+++ b/sys/platform/vkernel/platform/kqueue.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/platform/vkernel/platform/kqueue.c,v 1.2 2007/01/15 05:27:31 dillon Exp $
+ * $DragonFly: src/sys/platform/vkernel/platform/kqueue.c,v 1.3 2007/01/15 19:08:10 dillon Exp $
  */
 
 #include <sys/types.h>
@@ -166,6 +166,8 @@ kqueue_reload_timer(struct kqueue_info *info, int ms)
 	struct timespec ts = { 0, 0 };
 	struct kevent kev;
 
+	KKASSERT(ms > 0);
+
 	EV_SET(&kev, info->fd, EVFILT_TIMER,
 		EV_ADD|EV_ENABLE|EV_ONESHOT|EV_CLEAR, 0, (uintptr_t)ms, info);
 	if (kevent(KQueueFd, &kev, 1, NULL, 0, &ts) < 0)
diff --git a/sys/platform/vkernel/platform/systimer.c b/sys/platform/vkernel/platform/systimer.c
index 87c51122e2..73ccbfba44 100644
--- a/sys/platform/vkernel/platform/systimer.c
+++ b/sys/platform/vkernel/platform/systimer.c
@@ -31,7 +31,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * 
- * $DragonFly: src/sys/platform/vkernel/platform/systimer.c,v 1.10 2007/01/15 05:27:31 dillon Exp $
+ * $DragonFly: src/sys/platform/vkernel/platform/systimer.c,v 1.11 2007/01/15 19:08:10 dillon Exp $
  */
 
 #include <sys/types.h>
@@ -135,13 +135,18 @@ cputimer_intr_config(struct cputimer *timer)
 }
 
 /*
- * Reload the interrupt for our core systimer.
+ * Reload the interrupt for our core systimer.  Because the caller's
+ * reload calculation can be negatively indexed, we need a minimal
+ * check to ensure that a reasonable reload value is selected. 
  */
 void
 cputimer_intr_reload(sysclock_t reload)
 {
-	if (kqueue_timer_info)
+	if (kqueue_timer_info) {
+		if ((int)reload < 1)
+			reload = 1;
 		kqueue_reload_timer(kqueue_timer_info, (reload + 999) / 1000);
+	}
 }
 
 /*