Re: [PATCH v6 1/7] tpm: dynamically allocate the allocated_banks array

[Ken Goldman <kgold@xxxxxxxxxxxxx>]

On 12/4/2018 6:18 PM, Jarkko Sakkinen wrote:
> > +		for (j = 0; j < pcr_selection.size_of_select; j++)
> > +			if (pcr_selection.pcr_select[j])
> > +				break;
> > +
> > +		if (j < pcr_selection.size_of_select) {
> > +			chip->allocated_banks[nr_alloc_banks] = hash_alg;
> > +			nr_alloc_banks++;
> > +		}
> > +
>
> Why was this needed? Can CAP_PCRS return completely unallocated banks?

Yes.  E.g., here's a TPM with 4 hash algorithms and two banks with 
allocated PCRs.

> getcapability -cap 5
4 PCR selections
    hash TPM_ALG_SHA1
    TPMS_PCR_SELECTION length 3
    ff ff ff
    hash TPM_ALG_SHA256
    TPMS_PCR_SELECTION length 3
    ff ff ff
    hash TPM_ALG_SHA384
    TPMS_PCR_SELECTION length 3
    00 00 00
    hash TPM_ALG_SHA512
    TPMS_PCR_SELECTION length 3
    00 00 00