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SubjectRe: [PATCH v3 1/2] tpm: implement TPM 2.0 capability to get active PCR banks
On Fri, Jan 13, 2017 at 12:54:12PM +0530, Nayna wrote:
>
>
> On 01/12/2017 11:55 PM, Jarkko Sakkinen wrote:
> > On Thu, Jan 12, 2017 at 11:58:09AM -0500, Nayna Jain wrote:
> > > This patch implements the TPM 2.0 capability TPM_CAP_PCRS to
> > > retrieve the active PCR banks from the TPM. This is needed
> > > to enable extending all active banks as recommended by TPM 2.0
> > > TCG Specification.
> > >
> > > Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> > > ---
> > > drivers/char/tpm/tpm.h | 4 +++
> > > drivers/char/tpm/tpm2-cmd.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
> > > 2 files changed, 63 insertions(+)
> > >
> > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > > index 1ae9768..dddd573 100644
> > > --- a/drivers/char/tpm/tpm.h
> > > +++ b/drivers/char/tpm/tpm.h
> > > @@ -127,6 +127,7 @@ enum tpm2_permanent_handles {
> > > };
> > >
> > > enum tpm2_capabilities {
> > > + TPM2_CAP_PCRS = 5,
> > > TPM2_CAP_TPM_PROPERTIES = 6,
> > > };
> > >
> > > @@ -187,6 +188,8 @@ struct tpm_chip {
> > >
> > > const struct attribute_group *groups[3];
> > > unsigned int groups_cnt;
> > > +
> > > + u16 active_banks[7];
> > > #ifdef CONFIG_ACPI
> > > acpi_handle acpi_dev_handle;
> > > char ppi_version[TPM_PPI_VERSION_LEN + 1];
> > > @@ -545,4 +548,5 @@ int tpm2_auto_startup(struct tpm_chip *chip);
> > > void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type);
> > > unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
> > > int tpm2_probe(struct tpm_chip *chip);
> > > +ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip);
> > > #endif
> > > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> > > index 6eda239..87388921 100644
> > > --- a/drivers/char/tpm/tpm2-cmd.c
> > > +++ b/drivers/char/tpm/tpm2-cmd.c
> > > @@ -83,6 +83,12 @@ struct tpm2_get_tpm_pt_out {
> > > __be32 value;
> > > } __packed;
> > >
> > > +struct tpm2_tpms_pcr_selection {
> > > + __be16 hash_alg;
> > > + u8 size_of_select;
> > > + u8 pcr_select[3];
> > > +} __packed;
> >
> > Please move this right before tpm2_get_pcr_allocation.
> > Drop 'tpms_'.
>
> Sure, will do this. But didn't understand why. I think all structs are
> defined in start of file..
>
> Thanks & Regards,
> - Nayna
>
> >
> > > +
> > > struct tpm2_get_random_in {
> > > __be16 size;
> > > } __packed;
> > > @@ -993,8 +999,61 @@ int tpm2_auto_startup(struct tpm_chip *chip)
> > > }
> > > }
> > >
> > > + rc = tpm2_get_pcr_allocation(chip);
> > > +
> >
> > Please have this call in the commit where you actually use it
> > Does not make any sense here
> >
> > > out:
> > > if (rc > 0)
> > > rc = -ENODEV;
> > > return rc;
> > > }
> > > +
> > > +/**
> > > + * tpm2_get_pcr_allocation() - get TPM active PCR banks.
> > > + *
> > > + * @chip: TPM chip to use.
> > > + *
> > > + * Return: Same as with tpm_transmit_cmd.
> > > + */
> > > +ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> > > +{
> > > + struct tpm2_tpms_pcr_selection pcr_selection;
> > > + struct tpm_buf buf;
> > > + void *marker;
> > > + unsigned int count = 0;
> > > + int rc;
> > > + int i;
> > > +
> > > + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
> > > + if (rc)
> > > + return rc;
> > > +
> > > + tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
> > > + tpm_buf_append_u32(&buf, 0);
> > > + tpm_buf_append_u32(&buf, 1);
> > > +
> > > + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0,
> > > + "get tpm pcr allocation");
> > > + if (rc < 0)
> > > + goto out;
> > > +
> > > + count = be32_to_cpup(
> > > + (__be32 *) &buf.data[TPM_HEADER_SIZE + 5]);
> >
> > Please do not add a space after cast. This has been an issue in your
> > previous patches too so try to do it right next time.

It is only used internally by that function. I think this would
make sense for other structures too that are only used by one
function.

/Jarkko

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