Re: [PATCH 04/11] drm/r128: Fix undefined behavior due to shift overflowing the constant

[Randy Dunlap]

On 5/19/22 06:05, Daniel Vetter wrote:
> On Mon, Apr 25, 2022 at 11:46:53AM -0700, Randy Dunlap wrote:
>>
>>
>> On 4/5/22 08:15, Borislav Petkov wrote:
>>> From: Borislav Petkov <bp@xxxxxxx>
>>>
>>> Fix:
>>>
>>>   drivers/gpu/drm/r128/r128_cce.c: In function ‘r128_do_init_cce’:
>>>   drivers/gpu/drm/r128/r128_cce.c:417:2: error: case label does not reduce to an integer constant
>>>     case R128_PM4_64BM_64VCBM_64INDBM:
>>>     ^~~~
>>>   drivers/gpu/drm/r128/r128_cce.c:418:2: error: case label does not reduce to an integer constant
>>>     case R128_PM4_64PIO_64VCPIO_64INDPIO:
>>>     ^~~~
>>>
>>> See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@xxxxxxx for the gory
>>> details as to why it triggers with older gccs only.
>>>
>>> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
>>> Cc: David Airlie <airlied@xxxxxxxx>
>>> Cc: Daniel Vetter <daniel@xxxxxxxx>
>>> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
>>> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
>>
>> Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> 
> Pushed to drm-misc-next, thanks for patch&review.
> -Daniel
> 

Hi,

Will this be merged to mainline any time soonish?

thanks.

>>
>> Thanks.
>>
>>> ---
>>>  drivers/gpu/drm/r128/r128_drv.h | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/r128/r128_drv.h b/drivers/gpu/drm/r128/r128_drv.h
>>> index 2e1bc01aa5c9..970e192b0d51 100644
>>> --- a/drivers/gpu/drm/r128/r128_drv.h
>>> +++ b/drivers/gpu/drm/r128/r128_drv.h
>>> @@ -300,8 +300,8 @@ extern long r128_compat_ioctl(struct file *filp, unsigned int cmd,
>>>  #	define R128_PM4_64PIO_128INDBM		(5  << 28)
>>>  #	define R128_PM4_64BM_128INDBM		(6  << 28)
>>>  #	define R128_PM4_64PIO_64VCBM_64INDBM	(7  << 28)
>>> -#	define R128_PM4_64BM_64VCBM_64INDBM	(8  << 28)
>>> -#	define R128_PM4_64PIO_64VCPIO_64INDPIO	(15 << 28)
>>> +#	define R128_PM4_64BM_64VCBM_64INDBM	(8U  << 28)
>>> +#	define R128_PM4_64PIO_64VCPIO_64INDPIO	(15U << 28)
>>>  #	define R128_PM4_BUFFER_CNTL_NOUPDATE	(1  << 27)
>>>  
>>>  #define R128_PM4_BUFFER_WM_CNTL		0x0708
>>
>> -- 
>> ~Randy
> 

-- 
~Randy