Re: [PATCH 1/2] tpm: Move tpm_get_random api into the TPM devicedriver

From: Kent Yoder
Date: Fri Jul 27 2012 - 10:56:35 EST


On Thu, Jul 26, 2012 at 05:10:44PM -0700, H. Peter Anvin wrote:
> On 06/07/2012 11:47 AM, Kent Yoder wrote:
> >Move the tpm_get_random api from the trusted keys code into the TPM
> >device driver itself so that other callers can make use of it. Also,
> >change the api slightly so that the number of bytes read is returned in
> >the call, since the TPM command can potentially return fewer bytes than
> >requested.
> >
> >Signed-off-by: Kent Yoder <key@xxxxxxxxxxxxxxxxxx>
>
> I see a second problem with this patch: you don't seem to handle the
> case where you get a short return anywhere in your code. Presumably
> this should either be considered an error condition, or you need to
> create a private wrapper which can loop and make additional
> requests.
>
> As it is if you get a short return you simply proceed as if you had
> gotten what you requested, since this was not an error mode
> supported by the old code.

Right, I did notice this but didn't think I was creating a regression
so I left it. I'll add both a loop and then error out if that fails.

Thanks,
Kent

>
> -hpa
>
> --
> H. Peter Anvin, Intel Open Source Technology Center
> I work for Intel. I don't speak on their behalf.
>

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