Re: [PATCH] drm/amdkfd: dqm fence memory corruption

[Qu Huang <jinsdb@126.com>]

On 2021/1/28 5:50, Felix Kuehling wrote:
> Am 2021-01-27 um 7:33 a.m. schrieb Qu Huang:
>> Amdgpu driver uses 4-byte data type as DQM fence memory,
>> and transmits GPU address of fence memory to microcode
>> through query status PM4 message. However, query status
>> PM4 message definition and microcode processing are all
>> processed according to 8 bytes. Fence memory only allocates
>> 4 bytes of memory, but microcode does write 8 bytes of memory,
>> so there is a memory corruption.
> 
> Thank you for pointing out that discrepancy. That's a good catch!
> 
> I'd prefer to fix this properly by making dqm->fence_addr a u64 pointer.
> We should probably also fix up the query_status and
> amdkfd_fence_wait_timeout function interfaces to use a 64 bit fence
> values everywhere to be consistent.
> 
> Regards,
>    Felix
Hi Felix, Thanks for your advice, please check v2 at 
https://lore.kernel.org/patchwork/patch/1372584/
Thanks,
Qu.
> 
> 
>>
>> Signed-off-by: Qu Huang <jinsdb@126.com>
>> ---
>>   drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> index e686ce2..8b38d0c 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> @@ -1161,7 +1161,7 @@ static int start_cpsch(struct device_queue_manager *dqm)
>>   	pr_debug("Allocating fence memory\n");
>>   
>>   	/* allocate fence memory on the gart */
>> -	retval = kfd_gtt_sa_allocate(dqm->dev, sizeof(*dqm->fence_addr),
>> +	retval = kfd_gtt_sa_allocate(dqm->dev, sizeof(uint64_t),
>>   					&dqm->fence_mem);
>>   
>>   	if (retval)