On 09/02/18 09:56 AM, Christian König wrote:
> Am 09.02.2018 um 15:51 schrieb Tom St Denis:
>> On 09/02/18 09:12 AM, Christian König wrote:
>>> No, there is simply no need to initialize the system domain. What are
>>> the values of p->mapping and adev->mman.bdev.dev_mapping when they
>>> don't match? Maybe we are allocating memory before initializing
>>> adev->mman.bdev.dev_mapping.
>>
>> In my test setup I'm running test 3 from libdrm (suite 1) with a pause
>> before the unmap/free call. So the IB should still be mapped. Indeed
>> the VM PTE decoding has the V bit set.
>>
>>> Or do you have more than one GPU in the system? E.g. APU+dGPU? Could
>>> it be that you read through the wrong device?
>>
>> I found the issue:
>>
>> Â Â Â Â while (size) {
>> Â Â Â Â Â Â Â phys_addr_t addr = *pos & PAGE_MASK;
>> Â Â Â Â Â Â Â loff_t off = *pos & ~PAGE_MASK;
>> Â Â Â Â Â Â Â size_t bytes = PAGE_SIZE - off;
>>
>> "bytes" should be limited by the 'size' parameter passed in. What is
>> happening instead is it's reading the entire PTB until it hits a V=0
>> page and then returns an error and in the process is doing "fun
>> things" to the user mode application (by copying more data than I
>> asked for).
>
> Ah, obvious problem.
>
> Do you want to fix it or should I take a look? You wanted to add write
> support as well anyway IIRC.
Yup, I can tackle this this afternoon.
I'll take your read only patch and make it do both read/write (and fix
the minor error).
Tom
