[PATCH] drm/amdgpu: don't try to unreserve NULL pointer

[Christian König]

Am 18.09.2018 um 08:16 schrieb Zhu, Rex:
>
>> -----Original Message-----
>> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
>> Christian König
>> Sent: Tuesday, September 18, 2018 2:07 AM
>> To: amd-gfx at lists.freedesktop.org
>> Subject: [PATCH] drm/amdgpu: don't try to unreserve NULL pointer
>>
>> Don't try to unreserve a BO we doesn't allocated.
>>
>> Fixes: 07012fdd497e drm/amdgpu: don't allocate zero sized kernel BOs
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> index 84d82d5382f9..c1387efc0c91 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> @@ -348,7 +348,8 @@ int amdgpu_bo_create_kernel(struct amdgpu_device
>> *adev,
>>   	if (r)
>>   		return r;
>>
>> -	amdgpu_bo_unreserve(*bo_ptr);
>> +	if (*bo_ptr)
>> +		amdgpu_bo_unreserve(*bo_ptr);
>>
>>   	return 0;
>>   }
> It is weird.
> If we return true for allocate bo with size  0.
> Does that mean we need to check all the bo_ptr before we use them.

No, allocating a BO with zero size doesn't make much sense and was 
essentially undefined behavior previously.

So now we get a defined behavior, but not necessary the one you expected.

Is that only a rhetorical question or really a problem somewhere?

Regards,
Christian.

>
> Best Regards
> Rex
>   
>> --
>> 2.14.1
>>
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