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Date: Fri, 10 Jun 2016 15:19:57 +0300
From: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To: Ed Swierk <eswierk@...portsystems.com>
Cc: tpmdd-devel@...ts.sourceforge.net, stefanb@...ibm.com,
linux-kernel@...r.kernel.org,
linux-security-module@...r.kernel.org,
jgunthorpe@...idianresearch.com
Subject: Re: [PATCH v5 3/4] tpm: Allow TPM chip drivers to override reported
command durations
On Wed, Jun 08, 2016 at 04:00:17PM -0700, Ed Swierk wrote:
> Some TPM chips report bogus command durations in their capabilities,
> just as others report incorrect timeouts. Rework tpm_get_timeouts()
> to allow chip drivers to override either via a single callback.
> Also clean up handling of TPMs that report milliseconds instead of
> microseconds.
>
> Signed-off-by: Ed Swierk <eswierk@...portsystems.com>
> ---
> drivers/char/tpm/tpm-interface.c | 177 +++++++++++++++++++++------------------
> drivers/char/tpm/tpm_tis.c | 35 ++------
> include/linux/tpm.h | 3 +-
> 3 files changed, 106 insertions(+), 109 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index cc1e5bc..b8a08bb 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -502,123 +502,138 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
> "attempting to start the TPM");
> }
>
> -int tpm_get_timeouts(struct tpm_chip *chip)
> +static int tpm_get_cap_prop(struct tpm_chip *chip, __be32 type, int size,
> + cap_t *cap, char *desc)
> {
> struct tpm_cmd_t tpm_cmd;
> - unsigned long new_timeout[4];
> - unsigned long old_timeout[4];
> - struct duration_t *duration_cap;
> ssize_t rc;
>
> tpm_cmd.header.in = tpm_getcap_header;
> tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> - tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> + tpm_cmd.params.getcap_in.subcap = type;
> rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
>
> if (rc == TPM_ERR_INVALID_POSTINIT) {
> /* The TPM is not started, we are the first to talk to it.
> Execute a startup command. */
> - dev_info(chip->pdev, "Issuing TPM_STARTUP");
> + dev_info(chip->pdev, "Issuing TPM_STARTUP\n");
> if (tpm_startup(chip, TPM_ST_CLEAR))
> return rc;
>
> tpm_cmd.header.in = tpm_getcap_header;
> tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> - tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
> + tpm_cmd.params.getcap_in.subcap = type;
> rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> NULL);
> }
> +
> if (rc) {
> dev_err(chip->pdev,
> - "A TPM error (%zd) occurred attempting to determine the timeouts\n",
> - rc);
> - goto duration;
> + "Error %zd reading %s\n", rc, desc);
> + return -EINVAL;
> }
>
> if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
> be32_to_cpu(tpm_cmd.header.out.length)
> - != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
> + != sizeof(tpm_cmd.header.out) + sizeof(u32) + size * sizeof(u32)) {
> + dev_err(chip->pdev,
> + "Bad return code or length reading %s\n", desc);
> return -EINVAL;
> -
> - old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
> - old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
> - old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
> - old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
> - memcpy(new_timeout, old_timeout, sizeof(new_timeout));
> -
> - /*
> - * Provide ability for vendor overrides of timeout values in case
> - * of misreporting.
> - */
> - if (chip->ops->update_timeouts != NULL)
> - chip->vendor.timeout_adjusted =
> - chip->ops->update_timeouts(chip, new_timeout);
> -
> - if (!chip->vendor.timeout_adjusted) {
> - /* Don't overwrite default if value is 0 */
> - if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
> - int i;
> -
> - /* timeouts in msec rather usec */
> - for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
> - new_timeout[i] *= 1000;
> - chip->vendor.timeout_adjusted = true;
> - }
> }
>
> - /* Report adjusted timeouts */
> - if (chip->vendor.timeout_adjusted) {
> - dev_info(chip->pdev,
> - HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
> - old_timeout[0], new_timeout[0],
> - old_timeout[1], new_timeout[1],
> - old_timeout[2], new_timeout[2],
> - old_timeout[3], new_timeout[3]);
> - }
> + memcpy(cap, &tpm_cmd.params.getcap_out.cap, sizeof(cap_t));
>
> - chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
> - chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
> - chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
> - chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
> + return 0;
> +}
>
> -duration:
> - tpm_cmd.header.in = tpm_getcap_header;
> - tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
> - tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
> - tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
> +int tpm_get_timeouts(struct tpm_chip *chip)
> +{
> + cap_t cap1, cap2;
> + int rc1, rc2;
> + struct tpm_vendor_specific orig_vendor;
> +
> + rc1 = tpm_get_cap_prop(chip, TPM_CAP_PROP_TIS_TIMEOUT, 4, &cap1,
> + "timeouts");
> + if (rc1 == 0) {
> + be32_to_cpus(&cap1.timeout.a);
> + be32_to_cpus(&cap1.timeout.b);
> + be32_to_cpus(&cap1.timeout.c);
> + be32_to_cpus(&cap1.timeout.d);
> + chip->vendor.timeout_a = usecs_to_jiffies(cap1.timeout.a);
> + chip->vendor.timeout_b = usecs_to_jiffies(cap1.timeout.b);
> + chip->vendor.timeout_c = usecs_to_jiffies(cap1.timeout.c);
> + chip->vendor.timeout_d = usecs_to_jiffies(cap1.timeout.d);
> + }
> + rc2 = tpm_get_cap_prop(chip, TPM_CAP_PROP_TIS_DURATION, 3, &cap2,
> + "durations");
> + if (rc2 == 0) {
> + be32_to_cpus(&cap2.duration.tpm_short);
> + be32_to_cpus(&cap2.duration.tpm_medium);
> + be32_to_cpus(&cap2.duration.tpm_long);
> + chip->vendor.duration[TPM_SHORT] =
> + usecs_to_jiffies(cap2.duration.tpm_short);
> + chip->vendor.duration[TPM_MEDIUM] =
> + usecs_to_jiffies(cap2.duration.tpm_medium);
> + chip->vendor.duration[TPM_LONG] =
> + usecs_to_jiffies(cap2.duration.tpm_long);
> + }
This is major change to the semantics. Before -EINVAL would have been
return on error condition.
PS If you want to encapsulate tpm_get_cap_prop(), that step should be
a separate commit (prepend this one).
/Jarkko
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