drm/i915/gvt: fix a bounds check in ring_id_to_context_switch_event()

Commit Message

Dan Carpenter April 13, 2017, 7:48 p.m. UTC

There are two bugs here.  The && should be || and the > is off by one so
it should be >= ARRAY_SIZE().

Fixes: 8453d674ae7e ("drm/i915/gvt: vGPU execlist virtualization")
Signed-off-by: Dan Carpenter <[e-mail]>

Patch

diff --git a/drivers/gpu/drm/i915/gvt/execlist.c b/drivers/gpu/drm/i915/gvt/execlist.c
index 536bde8638c8..026c491716d5 100644
--- a/drivers/gpu/drm/i915/gvt/execlist.c
+++ b/drivers/gpu/drm/i915/gvt/execlist.c
@@ -56,8 +56,8 @@  static int context_switch_events[] = {
 
 static int ring_id_to_context_switch_event(int ring_id)
 {
-	if (WARN_ON(ring_id < RCS && ring_id >
-				ARRAY_SIZE(context_switch_events)))
+	if (WARN_ON(ring_id < RCS ||
+		    ring_id >= ARRAY_SIZE(context_switch_events)))
 		return -EINVAL;
 
 	return context_switch_events[ring_id];