2023-06-05 18:29:50

by Alexander Steffen

Subject: [PATCH v2 2/4] tpm_tis: Move CRC check to generic send routine

The CRC functionality is initialized before tpm_tis_core, so it can be used
on all code paths within the module. Therefore, move the CRC check to the
generic send routine, that also contains all other checks for successful
command transmission, so that all those checks are in one place.

Also, this ensures that tpm_tis_ready is called when a CRC failure is
detected, to clear the invalid data from the TPM, which did not happen
previously.

Signed-off-by: Alexander Steffen <[email protected]>
---
drivers/char/tpm/tpm_tis_core.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index aaaa136044ae..5ddaf24518be 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -466,6 +466,12 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
goto out_err;
}

+ rc = tpm_tis_verify_crc(priv, len, buf);
+ if (rc < 0) {
+ dev_err(&chip->dev, "CRC mismatch for command.\n");
+ goto out_err;
+ }
+
return 0;

out_err:
@@ -510,12 +516,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
if (rc < 0)
return rc;

- rc = tpm_tis_verify_crc(priv, len, buf);
- if (rc < 0) {
- dev_err(&chip->dev, "CRC mismatch for command.\n");
- return rc;
- }
-
/* go and do it */
rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
if (rc < 0)
--
2.34.1

2023-06-06 21:25:14

by Jarkko Sakkinen

Subject: Re: [PATCH v2 2/4] tpm_tis: Move CRC check to generic send routine

On Mon Jun 5, 2023 at 8:59 PM EEST, Alexander Steffen wrote:
> The CRC functionality is initialized before tpm_tis_core, so it can be used
> on all code paths within the module. Therefore, move the CRC check to the
> generic send routine, that also contains all other checks for successful
> command transmission, so that all those checks are in one place.
>
> Also, this ensures that tpm_tis_ready is called when a CRC failure is
> detected, to clear the invalid data from the TPM, which did not happen
> previously.
>
> Signed-off-by: Alexander Steffen <[email protected]>
> ---
> drivers/char/tpm/tpm_tis_core.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index aaaa136044ae..5ddaf24518be 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -466,6 +466,12 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
> goto out_err;
> }
>
> + rc = tpm_tis_verify_crc(priv, len, buf);
> + if (rc < 0) {
> + dev_err(&chip->dev, "CRC mismatch for command.\n");
> + goto out_err;
> + }
> +
> return 0;
>
> out_err:
> @@ -510,12 +516,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
> if (rc < 0)
> return rc;
>
> - rc = tpm_tis_verify_crc(priv, len, buf);
> - if (rc < 0) {
> - dev_err(&chip->dev, "CRC mismatch for command.\n");
> - return rc;
> - }
> -
> /* go and do it */
> rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
> if (rc < 0)
> --
> 2.34.1

Reviewed-by: Jarkko Sakkinen <[email protected]>

BR, Jarkko