# Re: ibmvtpm byteswapping inconsistency

- From: Vicky \<hidden\>
- Date: 2017-02-02 04:41:38 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2017/02/4925793
- Thread: https://ratatoskr.run/linuxppc-dev/2017/01/4921209/t.md

```text

> On Jan 26, 2017, at 5:58 PM, Ashley Lai [ref] wrote:
>=20
> Adding Vicky from IBM.
>=20
>=20
> On 01/26/2017 04:05 PM, Jason Gunthorpe wrote:
>> On Thu, Jan 26, 2017 at 09:22:48PM +0100, Michal Such??nek wrote:
>>=20
>>> 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...
>>=20
>>> However, in tpm_ibmvtpm_send the structure is initialized as
>>>=20
>>> 	struct ibmvtpm_crq crq;
>>>         __be64 *word =3D (__be64 *)&crq;
>>> ...
>>>         crq.valid =3D (u8)IBMVTPM_VALID_CMD;
>>>         crq.msg =3D (u8)VTPM_TPM_COMMAND;
>>>         crq.len =3D cpu_to_be16(count);
>>>         crq.data =3D cpu_to_be32(ibmvtpm->rtce_dma_handle);
>>>=20
>>> and submitted with
>>>=20
>>> 	rc =3D 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.
>>=20
>> My guess is that '__be64 *word' should be 'u64 *word'...
>>=20
>> Jason
>=20

I don=92t think we want =91word' to be changed back to be of type =91u64=92=
.   Please see commit 62dfd912ab3b5405b6fe72d0135c37e9648071f1


Vicky=
```