[PATCH 4.19 062/168] drm/arm: fix unintentional integer overflow on left shift

Greg Kroah-Hartman
2020-08-17T17:47:32Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit 5f368ddea6fec519bdb93b5368f6a844b6ea27a6 ]

Shifting the integer value 1 is evaluated using 32-bit arithmetic
and then used in an expression that expects a long value leads to
a potential integer overflow. Fix this by using the BIT macro to
perform the shift to avoid the overflow.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: ad49f8602fe8 ("drm/arm: Add support for Mali Display Processors")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200618100400.11464-1-colin.king@canonical.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/arm/malidp_planes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/malidp_planes.c b/drivers/gpu/drm/arm/malidp_planes.c
index 29409a65d8647..a347b27405d88 100644
--- a/drivers/gpu/drm/arm/malidp_planes.c
+++ b/drivers/gpu/drm/arm/malidp_planes.c
@@ -446,7 +446,7 @@ int malidp_de_planes_init(struct drm_device *drm)
const struct malidp_hw_regmap *map = &malidp->dev->hw->map;
struct malidp_plane *plane = NULL;
enum drm_plane_type plane_type;
- unsigned long crtcs = 1 << drm->mode_config.num_crtc;
+ unsigned long crtcs = BIT(drm->mode_config.num_crtc);
unsigned long flags = DRM_MODE_ROTATE_0 | DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_180 |
DRM_MODE_ROTATE_270 | DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y;
u32 *formats;
--
2.25.1