[Mesa-dev] [PATCH] radeon: fixed division by zero

[Jakob Sinclair]

In the function r600_test_dma the max_width and max_height can be set to
zero. These variables are later used to do a modulo operation which can
lead to unexpected behavior if they are zero. This patch corrects that
by first checking if the max_width or max_height are zero and if they
are it sets width or height to one. Issue was discoverd by Coverity.

CID: 1361542, 1361543

Signed-off-by: Jakob Sinclair <sinclair.jakob at openmailbox.org>
---
 src/gallium/drivers/radeon/r600_test_dma.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/radeon/r600_test_dma.c b/src/gallium/drivers/radeon/r600_test_dma.c
index c203b4d..37d6202 100644
--- a/src/gallium/drivers/radeon/r600_test_dma.c
+++ b/src/gallium/drivers/radeon/r600_test_dma.c
@@ -345,8 +345,15 @@ void r600_test_dma(struct r600_common_screen *rscreen)
 					dstx = rand() % (tdst.width0 - width + 1) & ~0x7;
 					dsty = rand() % (tdst.height0 - height + 1) & ~0x7;
 				} else {
-					width = (rand() % max_width) + 1;
-					height = (rand() % max_height) + 1;
+					if (max_width == 0)
+						width = 1;
+					else
+						width = (rand() % max_width) + 1;
+
+					if (max_height == 0)
+						height = 1;
+					else
+						height = (rand() % max_height) + 1;
 
 					srcx = rand() % (tsrc.width0 - width + 1);
 					srcy = rand() % (tsrc.height0 - height + 1);
-- 
2.8.2