[Nouveau] [PATCH 1/9] drm/amd/pm: Annotate struct smu10_voltage_dependency_table with __counted_by

[Christian König]

Am 22.09.23 um 19:41 schrieb Alex Deucher:
> On Fri, Sep 22, 2023 at 1:32 PM Kees Cook <keescook at chromium.org> wrote:
>> Prepare for the coming implementation by GCC and Clang of the __counted_by
>> attribute. Flexible array members annotated with __counted_by can have
>> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
>> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
>> functions).
>>
>> As found with Coccinelle[1], add __counted_by for struct smu10_voltage_dependency_table.
>>
>> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>>
>> Cc: Evan Quan <evan.quan at amd.com>
>> Cc: Alex Deucher <alexander.deucher at amd.com>
>> Cc: "Christian König" <christian.koenig at amd.com>
>> Cc: "Pan, Xinhui" <Xinhui.Pan at amd.com>
>> Cc: David Airlie <airlied at gmail.com>
>> Cc: Daniel Vetter <daniel at ffwll.ch>
>> Cc: Xiaojian Du <Xiaojian.Du at amd.com>
>> Cc: Huang Rui <ray.huang at amd.com>
>> Cc: Kevin Wang <kevin1.wang at amd.com>
>> Cc: amd-gfx at lists.freedesktop.org
>> Cc: dri-devel at lists.freedesktop.org
>> Signed-off-by: Kees Cook <keescook at chromium.org>
> Acked-by: Alex Deucher <alexander.deucher at amd.com>

Mhm, I'm not sure if this is a good idea. That is a structure filled in 
by the firmware, isn't it?

That would imply that we might need to byte swap count before it is 
checkable.

Regards,
Christian.

>
>> ---
>>   drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu10_hwmgr.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu10_hwmgr.h b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu10_hwmgr.h
>> index 808e0ecbe1f0..42adc2a3dcbc 100644
>> --- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu10_hwmgr.h
>> +++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu10_hwmgr.h
>> @@ -192,7 +192,7 @@ struct smu10_clock_voltage_dependency_record {
>>
>>   struct smu10_voltage_dependency_table {
>>          uint32_t count;
>> -       struct smu10_clock_voltage_dependency_record entries[];
>> +       struct smu10_clock_voltage_dependency_record entries[] __counted_by(count);
>>   };
>>
>>   struct smu10_clock_voltage_information {
>> --
>> 2.34.1
>>