diff mbox series

[v9,14/19] tpm: Ensure tpm is in known state at startup

Message ID 20240531010331.134441-15-ross.philipson@oracle.com
State New
Headers show
Series x86: Trenchboot secure dynamic launch Linux kernel support | expand

Commit Message

Ross Philipson May 31, 2024, 1:03 a.m. UTC
From: "Daniel P. Smith" <dpsmith@apertussolutions.com>

When tis core initializes, it assumes all localities are closed. There
are cases when this may not be the case. This commit addresses this by
ensuring all localities are closed before initializing begins.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
---
 drivers/char/tpm/tpm_tis_core.c | 11 ++++++++++-
 include/linux/tpm.h             |  6 ++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

Comments

Jarkko Sakkinen June 4, 2024, 8:14 p.m. UTC | #1
On Fri May 31, 2024 at 4:03 AM EEST, Ross Philipson wrote:
> From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
>
> When tis core initializes, it assumes all localities are closed. There

s/tis_core/tpm_tis_core/

> are cases when this may not be the case. This commit addresses this by
> ensuring all localities are closed before initializing begins.
>
> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
> Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
> ---
>  drivers/char/tpm/tpm_tis_core.c | 11 ++++++++++-
>  include/linux/tpm.h             |  6 ++++++
>  2 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 7c1761bd6000..9fb53bb3e73f 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -1104,7 +1104,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>  	u32 intmask;
>  	u32 clkrun_val;
>  	u8 rid;
> -	int rc, probe;
> +	int rc, probe, i;
>  	struct tpm_chip *chip;
>  
>  	chip = tpmm_chip_alloc(dev, &tpm_tis);
> @@ -1166,6 +1166,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>  		goto out_err;
>  	}
>  
> +	/*
> +	 * There are environments, like Intel TXT, that may leave a TPM

What else at this point than Intel TXT reflecting the state of the
mainline?

> +	 * locality open. Close all localities to start from a known state.
> +	 */
> +	for (i = 0; i <= TPM_MAX_LOCALITY; i++) {
> +		if (check_locality(chip, i))
> +			tpm_tis_relinquish_locality(chip, i);
> +	}

To be strict this should be enabled only for x86 platforms.

I.e. should be flagged.

> +
>  	/* Take control of the TPM's interrupt hardware and shut it off */
>  	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
>  	if (rc < 0)
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index c17e4efbb2e5..363f7078c3a9 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -147,6 +147,12 @@ struct tpm_chip_seqops {
>   */
>  #define TPM2_MAX_CONTEXT_SIZE 4096
>  
> +/*
> + * The maximum locality (0 - 4) for a TPM, as defined in section 3.2 of the
> + * Client Platform Profile Specification.
> + */
> +#define TPM_MAX_LOCALITY		4
> +
>  struct tpm_chip {
>  	struct device dev;
>  	struct device devs;


BR, Jarkko
Daniel P. Smith Aug. 15, 2024, 7:24 p.m. UTC | #2
On 6/4/24 16:14, Jarkko Sakkinen wrote:
> On Fri May 31, 2024 at 4:03 AM EEST, Ross Philipson wrote:
>> From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
>>
>> When tis core initializes, it assumes all localities are closed. There
> 
> s/tis_core/tpm_tis_core/

Ack.

>> are cases when this may not be the case. This commit addresses this by
>> ensuring all localities are closed before initializing begins.
>>
>> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
>> Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
>> ---
>>   drivers/char/tpm/tpm_tis_core.c | 11 ++++++++++-
>>   include/linux/tpm.h             |  6 ++++++
>>   2 files changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
>> index 7c1761bd6000..9fb53bb3e73f 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -1104,7 +1104,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>   	u32 intmask;
>>   	u32 clkrun_val;
>>   	u8 rid;
>> -	int rc, probe;
>> +	int rc, probe, i;
>>   	struct tpm_chip *chip;
>>   
>>   	chip = tpmm_chip_alloc(dev, &tpm_tis);
>> @@ -1166,6 +1166,15 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>   		goto out_err;
>>   	}
>>   
>> +	/*
>> +	 * There are environments, like Intel TXT, that may leave a TPM
> 
> What else at this point than Intel TXT reflecting the state of the
> mainline?

Leaving the TPM in Locality 2 is a requirement of the TCG D-RTM 
specification. This will be the situation for AMD and Arm as well. The 
comment can be updated to ref the TCG spec instead of a specific 
implementation.

>> +	 * locality open. Close all localities to start from a known state.
>> +	 */
>> +	for (i = 0; i <= TPM_MAX_LOCALITY; i++) {
>> +		if (check_locality(chip, i))
>> +			tpm_tis_relinquish_locality(chip, i);
>> +	}
> 
> To be strict this should be enabled only for x86 platforms.
> 
> I.e. should be flagged.

As mentioned above, this will also affect Arm.

>> +
>>   	/* Take control of the TPM's interrupt hardware and shut it off */
>>   	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
>>   	if (rc < 0)
>> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
>> index c17e4efbb2e5..363f7078c3a9 100644
>> --- a/include/linux/tpm.h
>> +++ b/include/linux/tpm.h
>> @@ -147,6 +147,12 @@ struct tpm_chip_seqops {
>>    */
>>   #define TPM2_MAX_CONTEXT_SIZE 4096
>>   
>> +/*
>> + * The maximum locality (0 - 4) for a TPM, as defined in section 3.2 of the
>> + * Client Platform Profile Specification.
>> + */
>> +#define TPM_MAX_LOCALITY		4
>> +
>>   struct tpm_chip {
>>   	struct device dev;
>>   	struct device devs;
> 
> 
> BR, Jarkko

v/r,
dps
diff mbox series

Patch

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 7c1761bd6000..9fb53bb3e73f 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1104,7 +1104,7 @@  int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	u32 intmask;
 	u32 clkrun_val;
 	u8 rid;
-	int rc, probe;
+	int rc, probe, i;
 	struct tpm_chip *chip;
 
 	chip = tpmm_chip_alloc(dev, &tpm_tis);
@@ -1166,6 +1166,15 @@  int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		goto out_err;
 	}
 
+	/*
+	 * There are environments, like Intel TXT, that may leave a TPM
+	 * locality open. Close all localities to start from a known state.
+	 */
+	for (i = 0; i <= TPM_MAX_LOCALITY; i++) {
+		if (check_locality(chip, i))
+			tpm_tis_relinquish_locality(chip, i);
+	}
+
 	/* Take control of the TPM's interrupt hardware and shut it off */
 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
 	if (rc < 0)
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index c17e4efbb2e5..363f7078c3a9 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -147,6 +147,12 @@  struct tpm_chip_seqops {
  */
 #define TPM2_MAX_CONTEXT_SIZE 4096
 
+/*
+ * The maximum locality (0 - 4) for a TPM, as defined in section 3.2 of the
+ * Client Platform Profile Specification.
+ */
+#define TPM_MAX_LOCALITY		4
+
 struct tpm_chip {
 	struct device dev;
 	struct device devs;