From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Roberto Sassu <roberto.sassu@huawei.com>
Cc: zohar@linux.ibm.com, david.safford@ge.com, monty.wiseman@ge.com,
linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com
Subject: Re: [PATCH v6 1/7] tpm: dynamically allocate the allocated_banks array
Date: Tue, 4 Dec 2018 15:18:48 -0800 [thread overview]
Message-ID: <20181204231848.GA1233@linux.intel.com> (raw)
In-Reply-To: <20181204082138.24600-2-roberto.sassu@huawei.com>
On Tue, Dec 04, 2018 at 09:21:32AM +0100, Roberto Sassu wrote:
> tpm2_get_pcr_allocation() determines if a PCR bank is allocated by checking
> the mask in the TPML_PCR_SELECTION structure returned by the TPM for
> TPM2_Get_Capability(). One PCR bank with algorithm set to SHA1 is always
> allocated for TPM 1.x.
...
> + 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?
Kind of out-of-context for the rest of the changes.
Should this be a bug fix of its own because it looks like as this is a
bug fix for existing code, and not a new feature? Just asking because
I don't yet fully understand this change.
Anyway, I believe that you can streamline this by:
/* Check that at least some of the PCRs have been allocated. This is
* required because CAP_PCRS ...
*/
if (memchr_inv(pcr_selection.pcr_select, 0, pcr_selection.size_of_select))
nr_allocated_banks++;
[yeah, comment would be awesome about CAP_PCRS. Did not finish up the
comment because I don't know the answer]
In addition, it would be consistent to call the local variable also
nr_allocated_banks (not nr_alloc_banks).
/Jarkko
next prev parent reply other threads:[~2018-12-04 23:18 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-04 8:21 [PATCH v6 0/7] tpm: retrieve digest size of unknown algorithms from TPM Roberto Sassu
2018-12-04 8:21 ` [PATCH v6 1/7] tpm: dynamically allocate the allocated_banks array Roberto Sassu
2018-12-04 23:18 ` Jarkko Sakkinen [this message]
2018-12-06 17:56 ` Roberto Sassu
2018-12-12 18:32 ` Jarkko Sakkinen
2018-12-13 8:14 ` Roberto Sassu
2018-12-11 21:01 ` Ken Goldman
2018-12-04 8:21 ` [PATCH v6 2/7] tpm: add _head suffix to tcg_efi_specid_event and tcg_pcr_event2 Roberto Sassu
2018-12-04 23:26 ` Jarkko Sakkinen
2018-12-09 12:10 ` Nayna Jain
2018-12-04 8:21 ` [PATCH v6 3/7] tpm: rename and export tpm2_digest and tpm2_algorithms Roberto Sassu
2018-12-04 8:21 ` [PATCH v6 4/7] tpm: modify tpm_pcr_read() definition to pass a TPM hash algorithm Roberto Sassu
2018-12-04 23:40 ` Jarkko Sakkinen
2018-12-05 20:31 ` Mimi Zohar
2018-12-06 19:49 ` Mimi Zohar
2018-12-07 14:51 ` Roberto Sassu
2018-12-09 20:32 ` Mimi Zohar
2018-12-10 7:55 ` Roberto Sassu
2018-12-06 8:14 ` Nayna Jain
2018-12-12 18:29 ` Jarkko Sakkinen
2018-12-09 12:04 ` Nayna Jain
2018-12-04 8:21 ` [PATCH v6 5/7] tpm: retrieve digest size of unknown algorithms with PCR read Roberto Sassu
2018-12-04 23:53 ` Jarkko Sakkinen
2018-12-06 18:00 ` Roberto Sassu
2018-12-12 18:16 ` Jarkko Sakkinen
2018-12-04 8:21 ` [PATCH v6 6/7] tpm: ensure that the output of PCR read contains the correct digest size Roberto Sassu
2018-12-05 0:09 ` Jarkko Sakkinen
2018-12-05 0:46 ` Jarkko Sakkinen
2018-12-06 18:07 ` Roberto Sassu
2018-12-12 18:18 ` Jarkko Sakkinen
2018-12-04 8:21 ` [PATCH v6 7/7] tpm: pass an array of tpm_bank_list structures to tpm_pcr_extend() Roberto Sassu
2018-12-05 0:14 ` Jarkko Sakkinen
2018-12-06 18:09 ` Roberto Sassu
2018-12-12 18:25 ` Jarkko Sakkinen
2018-12-06 18:38 ` Roberto Sassu
2018-12-12 18:27 ` Jarkko Sakkinen
2018-12-13 7:57 ` Roberto Sassu
2018-12-14 7:58 ` Jarkko Sakkinen
2018-12-05 0:21 ` [PATCH v6 0/7] tpm: retrieve digest size of unknown algorithms from TPM Jarkko Sakkinen
2018-12-05 0:23 ` Jarkko Sakkinen
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