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Subject[PATCH] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro
Date
With gcc-5 and CONFIG_UBSAN_SHIFT=y:

drivers/gpu/drm/msm/msm_mdss.c: In function 'msm_mdss_enable':
drivers/gpu/drm/msm/msm_mdss.c:296:2: error: case label does not reduce to an integer constant
case DPU_HW_VER_800:
^
drivers/gpu/drm/msm/msm_mdss.c:299:2: error: case label does not reduce to an integer constant
case DPU_HW_VER_810:
^
drivers/gpu/drm/msm/msm_mdss.c:300:2: error: case label does not reduce to an integer constant
case DPU_HW_VER_900:
^

This happens because for major revisions 8 or greather, the non-sign bit
of the major revision number is shifted into bit 31 of a signed integer,
which is undefined behavior.

Fix this by casting the major revision number to unsigned int.

Fixes: efcd0107727c4f04 ("drm/msm/dpu: add support for SM8550")
Fixes: 4a352c2fc15aec1e ("drm/msm/dpu: Introduce SC8280XP")
Fixes: 100d7ef6995d1f86 ("drm/msm/dpu: add support for SM8450")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
index ddab9caebb18c40d..bbd3cbdd77956c5d 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
@@ -19,8 +19,9 @@
*/
#define MAX_BLOCKS 12

-#define DPU_HW_VER(MAJOR, MINOR, STEP) (((MAJOR & 0xF) << 28) |\
- ((MINOR & 0xFFF) << 16) |\
+#define DPU_HW_VER(MAJOR, MINOR, STEP) \
+ ((((unsigned int)MAJOR & 0xF) << 28) | \
+ ((MINOR & 0xFFF) << 16) | \
(STEP & 0xFFFF))

#define DPU_HW_MAJOR(rev) ((rev) >> 28)
--
2.34.1
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