From: Christian König <deathsimple@vodafone.de>
Date: Wed, 2 May 2012 13:11:14 +0000 (+0200)
Subject: drm/radeon: fix a bug in the SA code
X-Git-Tag: v3.6-rc1~59^2~48
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=96050bca22f4fe6c8db175e02c8530a9720e5e9b;p=platform%2Fkernel%2Flinux-exynos.git

drm/radeon: fix a bug in the SA code

Aligning offset can make it bigger than tmp->offset
leading to an overrun bug in the following subtraction.

v2: Against initial suspicions this can't happen in mainline,
    so no need to push it into stable.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index 4cce47e..8fbfe69 100644
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -150,7 +150,7 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
 	offset = 0;
 	list_for_each_entry(tmp, &sa_manager->sa_bo, list) {
 		/* room before this object ? */
-		if ((tmp->offset - offset) >= size) {
+		if (offset < tmp->offset && (tmp->offset - offset) >= size) {
 			head = tmp->list.prev;
 			goto out;
 		}