Messages in this thread | | | Subject | Re: [PATCH v4 1/2] tpm: implement TPM 2.0 capability to get active PCR banks | From | Nayna <> | Date | Wed, 18 Jan 2017 19:19:06 +0530 |
| |
On 01/18/2017 07:15 PM, Jarkko Sakkinen wrote: > On Wed, Jan 18, 2017 at 03:44:49AM -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 | 57 +++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 61 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..75a7546 100644 >> --- a/drivers/char/tpm/tpm2-cmd.c >> +++ b/drivers/char/tpm/tpm2-cmd.c >> @@ -998,3 +998,60 @@ int tpm2_auto_startup(struct tpm_chip *chip) >> rc = -ENODEV; >> return rc; >> } >> + >> +struct tpm2_pcr_selection { >> + __be16 hash_alg; >> + u8 size_of_select; >> + u8 pcr_select[3]; >> +} __packed; >> + >> +/** >> + * 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_pcr_selection pcr_selection; >> + struct tpm_buf buf; >> + void *marker; >> + unsigned int count = 0; > > You shouldn't initialize 'count'.
It is initialized for reason below:
> >> + 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;
if tpm_transmit_cmd()fails, it jumps to out: where count is used in if(..).
Thanks & Regards, - Nayna
>> + >> + count = be32_to_cpup( >> + (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); >> + >> + if (count > ARRAY_SIZE(chip->active_banks)) >> + return -ENODEV; >> + >> + marker = &buf.data[TPM_HEADER_SIZE + 9]; >> + for (i = 0; i < count; i++) { >> + memcpy(&pcr_selection, marker, sizeof(pcr_selection)); >> + chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg); >> + marker = marker + sizeof(struct tpm2_pcr_selection); >> + } >> + >> +out: >> + if (count < ARRAY_SIZE(chip->active_banks)) >> + chip->active_banks[count] = 0; >> + >> + tpm_buf_destroy(&buf); >> + >> + return rc; >> +} >> -- >> 2.5.0 > > Otherwise, > > Reviewed-by: Jarkko Sakkinen <jarkko.sakkien@linux.intel.com> > > /Jarkko >
| |