Re: [PATCH v9 6/6] tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()

[Jarkko Sakkinen]

On Fri, Feb 01, 2019 at 11:06:41AM +0100, Roberto Sassu wrote:
> Currently, tpm_pcr_extend() accepts as an input only a SHA1 digest.
> 
> This patch replaces the hash parameter of tpm_pcr_extend() with an array of
> tpm_digest structures, so that the caller can provide a digest for each PCR
> bank currently allocated in the TPM.
> 
> tpm_pcr_extend() will not extend banks for which no digest was provided,
> as it happened before this patch, but instead it requires that callers
> provide the full set of digests. Since the number of digests will always be
> chip->nr_allocated_banks, the count parameter has been removed.
> 
> Due to the API change, ima_pcr_extend() and pcrlock() have been modified.
> Since the number of allocated banks is not known in advance, the memory for
> the digests must be dynamically allocated. To avoid performance degradation
> and to avoid that a PCR extend is not done due to lack of memory, the array
> of tpm_digest structures is allocated by the users of the TPM driver at
> initialization time.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>

/Jarkko