2023-04-26 17:37:57

by Jarkko Sakkinen

[permalink] [raw]
Subject: [PATCH 1/2] tpm_tis: Use tpm_chip_{start,stop} decoration inside tpm_tis_resume

Before sending a TPM command, CLKRUN protocol must be disabled. This is not
done in the case of tpm1_do_selftest() call site inside tpm_tis_resume().

Address this by decorating the calls with tpm_chip_{start,stop}, which arm
and disarm the TPM chip for transmission, and take care of disabling and
re-enabling CLKRUN, among other things.

Cc: [email protected]
Reported-by: Jason A. Donenfeld <[email protected]>
Link: https://lore.kernel.org/linux-integrity/CS68AWILHXS4.3M36M1EKZLUMS@suppilovahvero/
Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
drivers/char/tpm/tpm_tis_core.c | 43 +++++++++++++++------------------
1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c2421162cf34..73707026e358 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1209,25 +1209,20 @@ static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
u32 intmask;
int rc;

- if (chip->ops->clk_enable != NULL)
- chip->ops->clk_enable(chip, true);
-
- /* reenable interrupts that device may have lost or
- * BIOS/firmware may have disabled
+ /*
+ * Re-enable interrupts that device may have lost or BIOS/firmware may
+ * have disabled.
*/
rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
- if (rc < 0)
- goto out;
+ if (rc < 0) {
+ dev_err(&chip->dev, "Setting IRQ failed.\n");
+ return;
+ }

intmask = priv->int_mask | TPM_GLOBAL_INT_ENABLE;
-
- tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
-
-out:
- if (chip->ops->clk_enable != NULL)
- chip->ops->clk_enable(chip, false);
-
- return;
+ rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
+ if (rc < 0)
+ dev_err(&chip->dev, "Enabling interrupts failed.\n");
}

int tpm_tis_resume(struct device *dev)
@@ -1235,27 +1230,27 @@ int tpm_tis_resume(struct device *dev)
struct tpm_chip *chip = dev_get_drvdata(dev);
int ret;

- ret = tpm_tis_request_locality(chip, 0);
- if (ret < 0)
+ ret = tpm_chip_start(chip);
+ if (ret)
return ret;

if (chip->flags & TPM_CHIP_FLAG_IRQ)
tpm_tis_reenable_interrupts(chip);

- ret = tpm_pm_resume(dev);
- if (ret)
- goto out;
-
/*
* TPM 1.2 requires self-test on resume. This function actually returns
* an error code but for unknown reason it isn't handled.
*/
if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
tpm1_do_selftest(chip);
-out:
- tpm_tis_relinquish_locality(chip, 0);

- return ret;
+ tpm_chip_stop(chip);
+
+ ret = tpm_pm_resume(dev);
+ if (ret)
+ return ret;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(tpm_tis_resume);
#endif
--
2.39.2


2023-04-27 15:23:53

by Jerry Snitselaar

[permalink] [raw]
Subject: Re: [PATCH 1/2] tpm_tis: Use tpm_chip_{start,stop} decoration inside tpm_tis_resume

On Wed, Apr 26, 2023 at 08:29:27PM +0300, Jarkko Sakkinen wrote:
> Before sending a TPM command, CLKRUN protocol must be disabled. This is not
> done in the case of tpm1_do_selftest() call site inside tpm_tis_resume().
>
> Address this by decorating the calls with tpm_chip_{start,stop}, which arm
> and disarm the TPM chip for transmission, and take care of disabling and
> re-enabling CLKRUN, among other things.
>
> Cc: [email protected]
> Reported-by: Jason A. Donenfeld <[email protected]>
> Link: https://lore.kernel.org/linux-integrity/CS68AWILHXS4.3M36M1EKZLUMS@suppilovahvero/
> Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
> Signed-off-by: Jarkko Sakkinen <[email protected]>
> ---
> drivers/char/tpm/tpm_tis_core.c | 43 +++++++++++++++------------------
> 1 file changed, 19 insertions(+), 24 deletions(-)


Reviewed-by: Jerry Snitselaar <[email protected]

>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index c2421162cf34..73707026e358 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -1209,25 +1209,20 @@ static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
> u32 intmask;
> int rc;
>
> - if (chip->ops->clk_enable != NULL)
> - chip->ops->clk_enable(chip, true);
> -
> - /* reenable interrupts that device may have lost or
> - * BIOS/firmware may have disabled
> + /*
> + * Re-enable interrupts that device may have lost or BIOS/firmware may
> + * have disabled.
> */
> rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
> - if (rc < 0)
> - goto out;
> + if (rc < 0) {
> + dev_err(&chip->dev, "Setting IRQ failed.\n");
> + return;
> + }
>
> intmask = priv->int_mask | TPM_GLOBAL_INT_ENABLE;
> -
> - tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> -
> -out:
> - if (chip->ops->clk_enable != NULL)
> - chip->ops->clk_enable(chip, false);
> -
> - return;
> + rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
> + if (rc < 0)
> + dev_err(&chip->dev, "Enabling interrupts failed.\n");
> }
>
> int tpm_tis_resume(struct device *dev)
> @@ -1235,27 +1230,27 @@ int tpm_tis_resume(struct device *dev)
> struct tpm_chip *chip = dev_get_drvdata(dev);
> int ret;
>
> - ret = tpm_tis_request_locality(chip, 0);
> - if (ret < 0)
> + ret = tpm_chip_start(chip);
> + if (ret)
> return ret;
>
> if (chip->flags & TPM_CHIP_FLAG_IRQ)
> tpm_tis_reenable_interrupts(chip);
>
> - ret = tpm_pm_resume(dev);
> - if (ret)
> - goto out;
> -
> /*
> * TPM 1.2 requires self-test on resume. This function actually returns
> * an error code but for unknown reason it isn't handled.
> */
> if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
> tpm1_do_selftest(chip);
> -out:
> - tpm_tis_relinquish_locality(chip, 0);
>
> - return ret;
> + tpm_chip_stop(chip);
> +
> + ret = tpm_pm_resume(dev);
> + if (ret)
> + return ret;
> +
> + return 0;
> }
> EXPORT_SYMBOL_GPL(tpm_tis_resume);
> #endif
> --
> 2.39.2
>