From: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Mon, 6 Mar 2023 10:06:33 +0100
Subject: [PATCH] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: 4760be481dc075cd13f95f4650f5d5b53b4b336d

[ Upstream commit 4760be481dc075cd13f95f4650f5d5b53b4b336d ]

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>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/525152/
Link: https://lore.kernel.org/r/20230306090633.65918-1-geert+renesas@glider.be
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 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 e6590302..2c5bafac 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)
-- 
2.35.3