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SubjectRe: ibmvtpm byteswapping inconsistency
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> On Jan 26, 2017, at 5:58 PM, Ashley Lai <ashleydlai@gmail.com> wrote:
>
> Adding Vicky from IBM.
>
>
> On 01/26/2017 04:05 PM, Jason Gunthorpe wrote:
>> On Thu, Jan 26, 2017 at 09:22:48PM +0100, Michal Such??nek wrote:
>>
>>> This is repeated a few times in the driver so I added memset to quiet
>>> gcc and make behavior deterministic in case the unused fields get some
>>> meaning in the future.
>> Yep, reserved certainly needs to be zeroed.. Can you send a patch?
>> memset is overkill...
>>
>>> However, in tpm_ibmvtpm_send the structure is initialized as
>>>
>>> struct ibmvtpm_crq crq;
>>> __be64 *word = (__be64 *)&crq;
>>> ...
>>> crq.valid = (u8)IBMVTPM_VALID_CMD;
>>> crq.msg = (u8)VTPM_TPM_COMMAND;
>>> crq.len = cpu_to_be16(count);
>>> crq.data = cpu_to_be32(ibmvtpm->rtce_dma_handle);
>>>
>>> and submitted with
>>>
>>> rc = ibmvtpm_send_crq(ibmvtpm->vdev, be64_to_cpu(word[0]),
>>> be64_to_cpu(word[1]));
>>> meaning it is swapped twice.
>> No idea, Nayna may know.
>>
>> My guess is that '__be64 *word' should be 'u64 *word'...
>>
>> Jason
>

I don’t think we want ‘word' to be changed back to be of type ‘u64’. Please see commit 62dfd912ab3b5405b6fe72d0135c37e9648071f1


Vicky

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