[PATCH] drm/amdgpu: fix error handling in amdgpu_bo_do_create

[Christian König]

Am 31.10.2017 um 09:43 schrieb Michel Dänzer:
> On 31/10/17 09:37 AM, Christian König wrote:
>> From: Christian König <christian.koenig at amd.com>
>>
>> The bo structure is freed up in case of an error, so we can't do any
>> accounting if that happens.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> index e44b880eefdd..ff6f842655d1 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> @@ -369,6 +369,9 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
>>   	r = ttm_bo_init_reserved(&adev->mman.bdev, &bo->tbo, size, type,
>>   				 &bo->placement, page_align, !kernel, NULL,
>>   				 acc_size, sg, resv, &amdgpu_ttm_bo_destroy);
>> +	if (unlikely(r != 0))
>> +		return r;
>> +
>>   	bytes_moved = atomic64_read(&adev->num_bytes_moved) -
>>   		      initial_bytes_moved;
>>   	if (adev->mc.visible_vram_size < adev->mc.real_vram_size &&
>> @@ -378,9 +381,6 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
>>   	else
>>   		amdgpu_cs_report_moved_bytes(adev, bytes_moved, 0);
>>   
>> -	if (unlikely(r != 0))
>> -		return r;
>> -
>>   	if (kernel)
>>   		bo->tbo.priority = 1;
>>   
>>
> Hmm. If it's at least theoretically possible that ttm_bo_init_reserved
> moves some BOs before returning an error, we should instead make the
> accounting safe WRT bo having been freed. But assuming it's not possible,

I have made patches for this back in April and send them to the list, 
but the value is rather low and you need to change a lot of places in 
other drivers as well.

So I've gave up on that set for now because of lack of time.


> Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>

Thanks for the review,
Christian.

>
>