Re: [PATCH] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro

2023-03-28 Thread Dmitry Baryshkov 


On Mon, 06 Mar 2023 10:06:33 +0100, Geert Uytterhoeven wrote:
> 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:
>   ^
> 
> [...]

Applied, thanks!

[1/1] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro
  https://gitlab.freedesktop.org/lumag/msm/-/commit/c8f370bde5b9

Best regards,
-- 
Dmitry Baryshkov

Re: [PATCH] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro

2023-03-22 Thread Rob Clark 
On Tue, Mar 21, 2023 at 8:08 AM Randy Dunlap  wrote:
>
>
>
> On 3/6/23 01:06, Geert Uytterhoeven wrote:
> > 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 
>
> Reviewed-by: Randy Dunlap 

Reviewed-by: Rob Clark 

>
> Thanks.
>
> > ---
> >  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_BLOCKS12
> >
> > -#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 & 0x))
> >
> >  #define DPU_HW_MAJOR(rev)((rev) >> 28)
>
> --
> ~Randy

Re: [PATCH] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro

2023-03-21 Thread Randy Dunlap 



On 3/6/23 01:06, Geert Uytterhoeven wrote:
> 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 

Reviewed-by: Randy Dunlap 

Thanks.

> ---
>  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_BLOCKS12
>  
> -#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 & 0x))
>  
>  #define DPU_HW_MAJOR(rev)((rev) >> 28)

-- 
~Randy

[PATCH] drm/msm/dpu: Fix bit-shifting UB in DPU_HW_VER() macro

2023-03-06 Thread Geert Uytterhoeven 
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 
---
 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_BLOCKS12
 
-#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 & 0x))
 
 #define DPU_HW_MAJOR(rev)  ((rev) >> 28)
-- 
2.34.1