[tpmdd-devel,v4,1/2] tpm: Refactor tpm_transmit pulling out tpm_transfer function

Submitted by Stefan Berger on May 10, 2017, 11:54 p.m.

Details

Message ID 1494460462-29022-2-git-send-email-stefanb@linux.vnet.ibm.com
State New
Headers show

Commit Message

Stefan Berger May 10, 2017, 11:54 p.m.
Refactor tpm_transmit and pull out code sending the command
and receiving the response and put this into tpm_transfer.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm-interface.c | 121 +++++++++++++++++++++++----------------
 1 file changed, 73 insertions(+), 48 deletions(-)

Comments

Stefan Berger May 12, 2017, 1:30 p.m.
On 05/10/2017 07:54 PM, Stefan Berger wrote:
> Refactor tpm_transmit and pull out code sending the command
> and receiving the response and put this into tpm_transfer.
>
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> ---
>   drivers/char/tpm/tpm-interface.c | 121 +++++++++++++++++++++++----------------
>   1 file changed, 73 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 158c1db..263b6d1 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -370,67 +370,29 @@ static bool tpm_validate_command(struct tpm_chip *chip,
>   }
>
>   /**
> - * tmp_transmit - Internal kernel interface to transmit TPM commands.
> + * tmp_transfer - Send a TPM command to the TPM and receive response
>    *
>    * @chip: TPM chip to use
>    * @buf: TPM command buffer
> + * @count: size of the TPM command
>    * @bufsiz: length of the TPM command buffer
> - * @flags: tpm transmit flags - bitmap
>    *
>    * Return:
> - *     0 when the operation is successful.
> + *     >0 when the operation is successful; returns response length
>    *     A negative number for system errors (errno).
>    */
> -ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> -		     u8 *buf, size_t bufsiz, unsigned int flags)
> +ssize_t tpm_transfer(struct tpm_chip *chip, u8 *buf, u32 count, size_t bufsiz)
>   {
> -	struct tpm_output_header *header = (void *)buf;
>   	int rc;
> +	struct tpm_output_header *header = (void *)buf;
> +	u32 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
>   	ssize_t len = 0;
> -	u32 count, ordinal;
>   	unsigned long stop;
> -	bool need_locality;
> -
> -	if (!tpm_validate_command(chip, space, buf, bufsiz))
> -		return -EINVAL;
> -
> -	if (bufsiz > TPM_BUFSIZE)
> -		bufsiz = TPM_BUFSIZE;
> -
> -	count = be32_to_cpu(*((__be32 *) (buf + 2)));
> -	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> -	if (count == 0)
> -		return -ENODATA;
> -	if (count > bufsiz) {
> -		dev_err(&chip->dev,
> -			"invalid count value %x %zx\n", count, bufsiz);
> -		return -E2BIG;
> -	}
> -
> -	if (!(flags & TPM_TRANSMIT_UNLOCKED))
> -		mutex_lock(&chip->tpm_mutex);
> -
> -	if (chip->dev.parent)
> -		pm_runtime_get_sync(chip->dev.parent);
> -
> -	/* Store the decision as chip->locality will be changed. */
> -	need_locality = chip->locality == -1;
> -
> -	if (need_locality && chip->ops->request_locality)  {
> -		rc = chip->ops->request_locality(chip, 0);
> -		if (rc < 0)
> -			goto out_no_locality;
> -		chip->locality = rc;
> -	}
> -
> -	rc = tpm2_prepare_space(chip, space, ordinal, buf);
> -	if (rc)
> -		goto out;
>
>   	rc = chip->ops->send(chip, (u8 *) buf, count);
>   	if (rc < 0) {
>   		dev_err(&chip->dev,
> -			"tpm_transmit: tpm_send: error %d\n", rc);
> +			"tpm_transfer: tpm_send: error %d\n", rc);
>   		goto out;
>   	}
>
> @@ -467,18 +429,81 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
missing here: rc = 0;

>   	if (len < 0) {
>   		rc = len;
>   		dev_err(&chip->dev,
> -			"tpm_transmit: tpm_recv: error %d\n", rc);
> +			"tpm_transfer: tpm_recv: error %d\n", rc);
>   		goto out;
>   	} else if (len < TPM_HEADER_SIZE) {
>   		rc = -EFAULT;
>   		goto out;
>   	}
>
> -	if (len != be32_to_cpu(header->length)) {
> +	if (len != be32_to_cpu(header->length))
>   		rc = -EFAULT;
> -		goto out;
> +
> +out:
> +	return rc ? rc : len;
> +}
> +EXPORT_SYMBOL_GPL(tpm_transfer);
> +
> +/**
> + * tmp_transmit - Internal kernel interface to transmit TPM commands.
> + *
> + * @chip: TPM chip to use
> + * @buf: TPM command buffer
> + * @bufsiz: length of the TPM command buffer
> + * @flags: tpm transmit flags - bitmap
> + *
> + * Return:
> + *     0 when the operation is successful.
> + *     A negative number for system errors (errno).
> + */
> +ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> +		     u8 *buf, size_t bufsiz, unsigned int flags)
> +{
> +	int rc;
> +	ssize_t len = 0;
> +	u32 count, ordinal;
> +	bool need_locality;
> +
> +	if (!tpm_validate_command(chip, space, buf, bufsiz))
> +		return -EINVAL;
> +
> +	if (bufsiz > TPM_BUFSIZE)
> +		bufsiz = TPM_BUFSIZE;
> +
> +	count = be32_to_cpu(*((__be32 *) (buf + 2)));
> +	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> +	if (count == 0)
> +		return -ENODATA;
> +	if (count > bufsiz) {
> +		dev_err(&chip->dev,
> +			"invalid count value %x %zx\n", count, bufsiz);
> +		return -E2BIG;
> +	}
> +
> +	if (!(flags & TPM_TRANSMIT_UNLOCKED))
> +		mutex_lock(&chip->tpm_mutex);
> +
> +	if (chip->dev.parent)
> +		pm_runtime_get_sync(chip->dev.parent);
> +
> +	/* Store the decision as chip->locality will be changed. */
> +	need_locality = chip->locality == -1;
> +
> +	if (need_locality && chip->ops->request_locality)  {
> +		rc = chip->ops->request_locality(chip, 0);
> +		if (rc < 0)
> +			goto out_no_locality;
> +		chip->locality = rc;
>   	}
>
> +	rc = tpm2_prepare_space(chip, space, ordinal, buf);
> +	if (rc)
> +		goto out;
> +
> +	len = tpm_transfer(chip, buf, count, bufsiz);
> +	if (len < 0)
> +		goto out;
> +
>   	rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
>
>   out:



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Jarkko Sakkinen May 15, 2017, 12:40 p.m.
On Wed, May 10, 2017 at 07:54:21PM -0400, Stefan Berger wrote:
> Refactor tpm_transmit and pull out code sending the command
> and receiving the response and put this into tpm_transfer.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
> ---
>  drivers/char/tpm/tpm-interface.c | 121 +++++++++++++++++++++++----------------
>  1 file changed, 73 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 158c1db..263b6d1 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -370,67 +370,29 @@ static bool tpm_validate_command(struct tpm_chip *chip,
>  }
>  
>  /**
> - * tmp_transmit - Internal kernel interface to transmit TPM commands.
> + * tmp_transfer - Send a TPM command to the TPM and receive response
>   *
>   * @chip: TPM chip to use
>   * @buf: TPM command buffer
> + * @count: size of the TPM command
>   * @bufsiz: length of the TPM command buffer
> - * @flags: tpm transmit flags - bitmap
>   *
>   * Return:
> - *     0 when the operation is successful.
> + *     >0 when the operation is successful; returns response length
>   *     A negative number for system errors (errno).
>   */
> -ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> -		     u8 *buf, size_t bufsiz, unsigned int flags)
> +ssize_t tpm_transfer(struct tpm_chip *chip, u8 *buf, u32 count, size_t bufsiz)

Add instead a flag TPM_TRANSMIT_RAW (this name is just a suggestion)
that skips "prepare" and "commit" parts. That would save us from a
new export.

Better way to make it less messy would be to add static functions
tpm_prepare_command and tpm_commit_command that would be always
called and would return immediately if flags contain TPM_TRANSMIT_RAW.

/Jarkko

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Stefan Berger May 15, 2017, 4:04 p.m.
On 05/15/2017 08:40 AM, Jarkko Sakkinen wrote:
> On Wed, May 10, 2017 at 07:54:21PM -0400, Stefan Berger wrote:
>> Refactor tpm_transmit and pull out code sending the command
>> and receiving the response and put this into tpm_transfer.
>>
>> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
>> ---
>>   drivers/char/tpm/tpm-interface.c | 121 +++++++++++++++++++++++----------------
>>   1 file changed, 73 insertions(+), 48 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
>> index 158c1db..263b6d1 100644
>> --- a/drivers/char/tpm/tpm-interface.c
>> +++ b/drivers/char/tpm/tpm-interface.c
>> @@ -370,67 +370,29 @@ static bool tpm_validate_command(struct tpm_chip *chip,
>>   }
>>   
>>   /**
>> - * tmp_transmit - Internal kernel interface to transmit TPM commands.
>> + * tmp_transfer - Send a TPM command to the TPM and receive response
>>    *
>>    * @chip: TPM chip to use
>>    * @buf: TPM command buffer
>> + * @count: size of the TPM command
>>    * @bufsiz: length of the TPM command buffer
>> - * @flags: tpm transmit flags - bitmap
>>    *
>>    * Return:
>> - *     0 when the operation is successful.
>> + *     >0 when the operation is successful; returns response length
>>    *     A negative number for system errors (errno).
>>    */
>> -ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
>> -		     u8 *buf, size_t bufsiz, unsigned int flags)
>> +ssize_t tpm_transfer(struct tpm_chip *chip, u8 *buf, u32 count, size_t bufsiz)
> Add instead a flag TPM_TRANSMIT_RAW (this name is just a suggestion)
> that skips "prepare" and "commit" parts. That would save us from a
> new export.
>
> Better way to make it less messy would be to add static functions
> tpm_prepare_command and tpm_commit_command that would be always
> called and would return immediately if flags contain TPM_TRANSMIT_RAW.

I'll do that then, modifying the code to skip tpm_validate_command as well.

    Stefan

>
> /Jarkko
> --
> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
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>


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Stefan Berger May 15, 2017, 4:06 p.m.
On 05/15/2017 12:04 PM, Stefan Berger wrote:
> On 05/15/2017 08:40 AM, Jarkko Sakkinen wrote:
>> On Wed, May 10, 2017 at 07:54:21PM -0400, Stefan Berger wrote:
>>> Refactor tpm_transmit and pull out code sending the command
>>> and receiving the response and put this into tpm_transfer.
>>>
>>> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
>>> ---
>>>   drivers/char/tpm/tpm-interface.c | 121 
>>> +++++++++++++++++++++++----------------
>>>   1 file changed, 73 insertions(+), 48 deletions(-)
>>>
>>> diff --git a/drivers/char/tpm/tpm-interface.c 
>>> b/drivers/char/tpm/tpm-interface.c
>>> index 158c1db..263b6d1 100644
>>> --- a/drivers/char/tpm/tpm-interface.c
>>> +++ b/drivers/char/tpm/tpm-interface.c
>>> @@ -370,67 +370,29 @@ static bool tpm_validate_command(struct 
>>> tpm_chip *chip,
>>>   }
>>>     /**
>>> - * tmp_transmit - Internal kernel interface to transmit TPM commands.
>>> + * tmp_transfer - Send a TPM command to the TPM and receive response
>>>    *
>>>    * @chip: TPM chip to use
>>>    * @buf: TPM command buffer
>>> + * @count: size of the TPM command
>>>    * @bufsiz: length of the TPM command buffer
>>> - * @flags: tpm transmit flags - bitmap
>>>    *
>>>    * Return:
>>> - *     0 when the operation is successful.
>>> + *     >0 when the operation is successful; returns response length
>>>    *     A negative number for system errors (errno).
>>>    */
>>> -ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
>>> -             u8 *buf, size_t bufsiz, unsigned int flags)
>>> +ssize_t tpm_transfer(struct tpm_chip *chip, u8 *buf, u32 count, 
>>> size_t bufsiz)
>> Add instead a flag TPM_TRANSMIT_RAW (this name is just a suggestion)
>> that skips "prepare" and "commit" parts. That would save us from a
>> new export.
>>
>> Better way to make it less messy would be to add static functions
>> tpm_prepare_command and tpm_commit_command that would be always
>> called and would return immediately if flags contain TPM_TRANSMIT_RAW.
>
> I'll do that then, modifying the code to skip tpm_validate_command as 
> well.
>

But we don't want to recurse (in the 2nd patch) into 
chip->ops->request_locality(). Any suggestions ?

    Stefan


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Patch hide | download patch | download mbox

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 158c1db..263b6d1 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -370,67 +370,29 @@  static bool tpm_validate_command(struct tpm_chip *chip,
 }
 
 /**
- * tmp_transmit - Internal kernel interface to transmit TPM commands.
+ * tmp_transfer - Send a TPM command to the TPM and receive response
  *
  * @chip: TPM chip to use
  * @buf: TPM command buffer
+ * @count: size of the TPM command
  * @bufsiz: length of the TPM command buffer
- * @flags: tpm transmit flags - bitmap
  *
  * Return:
- *     0 when the operation is successful.
+ *     >0 when the operation is successful; returns response length
  *     A negative number for system errors (errno).
  */
-ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
-		     u8 *buf, size_t bufsiz, unsigned int flags)
+ssize_t tpm_transfer(struct tpm_chip *chip, u8 *buf, u32 count, size_t bufsiz)
 {
-	struct tpm_output_header *header = (void *)buf;
 	int rc;
+	struct tpm_output_header *header = (void *)buf;
+	u32 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 	ssize_t len = 0;
-	u32 count, ordinal;
 	unsigned long stop;
-	bool need_locality;
-
-	if (!tpm_validate_command(chip, space, buf, bufsiz))
-		return -EINVAL;
-
-	if (bufsiz > TPM_BUFSIZE)
-		bufsiz = TPM_BUFSIZE;
-
-	count = be32_to_cpu(*((__be32 *) (buf + 2)));
-	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
-	if (count == 0)
-		return -ENODATA;
-	if (count > bufsiz) {
-		dev_err(&chip->dev,
-			"invalid count value %x %zx\n", count, bufsiz);
-		return -E2BIG;
-	}
-
-	if (!(flags & TPM_TRANSMIT_UNLOCKED))
-		mutex_lock(&chip->tpm_mutex);
-
-	if (chip->dev.parent)
-		pm_runtime_get_sync(chip->dev.parent);
-
-	/* Store the decision as chip->locality will be changed. */
-	need_locality = chip->locality == -1;
-
-	if (need_locality && chip->ops->request_locality)  {
-		rc = chip->ops->request_locality(chip, 0);
-		if (rc < 0)
-			goto out_no_locality;
-		chip->locality = rc;
-	}
-
-	rc = tpm2_prepare_space(chip, space, ordinal, buf);
-	if (rc)
-		goto out;
 
 	rc = chip->ops->send(chip, (u8 *) buf, count);
 	if (rc < 0) {
 		dev_err(&chip->dev,
-			"tpm_transmit: tpm_send: error %d\n", rc);
+			"tpm_transfer: tpm_send: error %d\n", rc);
 		goto out;
 	}
 
@@ -467,18 +429,81 @@  ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 	if (len < 0) {
 		rc = len;
 		dev_err(&chip->dev,
-			"tpm_transmit: tpm_recv: error %d\n", rc);
+			"tpm_transfer: tpm_recv: error %d\n", rc);
 		goto out;
 	} else if (len < TPM_HEADER_SIZE) {
 		rc = -EFAULT;
 		goto out;
 	}
 
-	if (len != be32_to_cpu(header->length)) {
+	if (len != be32_to_cpu(header->length))
 		rc = -EFAULT;
-		goto out;
+
+out:
+	return rc ? rc : len;
+}
+EXPORT_SYMBOL_GPL(tpm_transfer);
+
+/**
+ * tmp_transmit - Internal kernel interface to transmit TPM commands.
+ *
+ * @chip: TPM chip to use
+ * @buf: TPM command buffer
+ * @bufsiz: length of the TPM command buffer
+ * @flags: tpm transmit flags - bitmap
+ *
+ * Return:
+ *     0 when the operation is successful.
+ *     A negative number for system errors (errno).
+ */
+ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
+		     u8 *buf, size_t bufsiz, unsigned int flags)
+{
+	int rc;
+	ssize_t len = 0;
+	u32 count, ordinal;
+	bool need_locality;
+
+	if (!tpm_validate_command(chip, space, buf, bufsiz))
+		return -EINVAL;
+
+	if (bufsiz > TPM_BUFSIZE)
+		bufsiz = TPM_BUFSIZE;
+
+	count = be32_to_cpu(*((__be32 *) (buf + 2)));
+	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+	if (count == 0)
+		return -ENODATA;
+	if (count > bufsiz) {
+		dev_err(&chip->dev,
+			"invalid count value %x %zx\n", count, bufsiz);
+		return -E2BIG;
+	}
+
+	if (!(flags & TPM_TRANSMIT_UNLOCKED))
+		mutex_lock(&chip->tpm_mutex);
+
+	if (chip->dev.parent)
+		pm_runtime_get_sync(chip->dev.parent);
+
+	/* Store the decision as chip->locality will be changed. */
+	need_locality = chip->locality == -1;
+
+	if (need_locality && chip->ops->request_locality)  {
+		rc = chip->ops->request_locality(chip, 0);
+		if (rc < 0)
+			goto out_no_locality;
+		chip->locality = rc;
 	}
 
+	rc = tpm2_prepare_space(chip, space, ordinal, buf);
+	if (rc)
+		goto out;
+
+	len = tpm_transfer(chip, buf, count, bufsiz);
+	if (len < 0)
+		goto out;
+
 	rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
 
 out: