diff mbox series

[v3,06/16] tpm: clean up tpm_try_transmit() error handling flow

Message ID 20181105014552.20262-7-jarkko.sakkinen@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Remove nested TPM operations | expand

Commit Message

Jarkko Sakkinen Nov. 5, 2018, 1:45 a.m. UTC 
Move locking, locality handling and power management to tpm_transmit()
in order to simplify the flow.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm-interface.c | 90 ++++++++++++++------------------
 1 file changed, 39 insertions(+), 51 deletions(-)

Comments

Stefan Berger Nov. 5, 2018, 10:20 p.m. UTC | #1 
On 11/4/18 8:45 PM, Jarkko Sakkinen wrote:
> Move locking, locality handling and power management to tpm_transmit()
> in order to simplify the flow.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>   drivers/char/tpm/tpm-interface.c | 90 ++++++++++++++------------------
>   1 file changed, 39 insertions(+), 51 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index ecda6f96cde0..0f343407daf8 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -171,7 +171,6 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
>   	ssize_t len = 0;
>   	u32 count, ordinal;
>   	unsigned long stop;
> -	bool need_locality;
>
>   	rc = tpm_validate_command(chip, space, buf, bufsiz);
>   	if (rc == -EINVAL)
> @@ -201,30 +200,9 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
>   		return -E2BIG;
>   	}
>
> -	if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
> -		mutex_lock(&chip->tpm_mutex);
> -
> -	if (chip->ops->clk_enable != NULL)
> -		chip->ops->clk_enable(chip, true);
> -
> -	/* Store the decision as chip->locality will be changed. */
> -	need_locality = chip->locality == -1;
> -
> -	if (need_locality) {
> -		rc = tpm_request_locality(chip, flags);
> -		if (rc < 0) {
> -			need_locality = false;
> -			goto out_locality;
> -		}
> -	}
> -
> -	rc = tpm_cmd_ready(chip, flags);
> -	if (rc)
> -		goto out_locality;
> -
>   	rc = tpm2_prepare_space(chip, space, ordinal, buf);


tpm2_prepare_space() may issue TPM commands itself. Following your tree 
the move should now put the clk_enable() and tpm_request_locality() in 
the path. So, looks good.


>   	if (rc)
> -		goto out_idle;
> +		return rc;
>
>   	rc = chip->ops->send(chip, buf, count);
>   	if (rc < 0) {
> @@ -265,40 +243,16 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
>   		rc = len;
>   		dev_err(&chip->dev,
>   			"tpm_transmit: tpm_recv: error %d\n", rc);
> -		goto out_idle;
> -	} else if (len < TPM_HEADER_SIZE) {
> -		rc = -EFAULT;
> -		goto out_idle;
> -	}
> -
> -	if (len != be32_to_cpu(header->length)) {
> +		tpm2_flush_space(chip);
> +	} else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
>   		rc = -EFAULT;
> -		goto out_idle;
> -	}
>
>   out_space:
> -	if (rc) {
> +	if (rc)
>   		tpm2_flush_space(chip);
> -	} else {
> +	else
>   		rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
> -		if (rc)
> -			dev_err(&chip->dev, "tpm2_commit_space: error %d\n",
> -				rc);


This should have been removed in the previous patch...


> -	}
> -
> -out_idle:
> -	/* may fail but do not override previous error value in rc */
> -	tpm_go_idle(chip, flags);
> -
> -out_locality:
> -	if (need_locality)
> -		tpm_relinquish_locality(chip, flags);
> -
> -	if (chip->ops->clk_enable != NULL)
> -		chip->ops->clk_enable(chip, false);
>
> -	if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
> -		mutex_unlock(&chip->tpm_mutex);
>   	return rc ? rc : len;
>   }
>
> @@ -328,6 +282,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
>   	/* space for header and handles */
>   	u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
>   	unsigned int delay_msec = TPM2_DURATION_SHORT;
> +	bool has_locality = false;
>   	u32 rc = 0;
>   	ssize_t ret;
>   	const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
> @@ -343,7 +298,40 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
>   	memcpy(save, buf, save_size);
>
>   	for (;;) {
> +		if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
> +		    !(flags & TPM_TRANSMIT_NESTED))
> +			mutex_lock(&chip->tpm_mutex);
> +
> +		if (chip->ops->clk_enable != NULL)
> +			chip->ops->clk_enable(chip, true);
> +
> +		if (chip->locality == -1) {
> +			ret = tpm_request_locality(chip, flags);
> +			if (ret)
> +				goto out_locality;
> +			has_locality = true;
> +		}
> +
> +		ret = tpm_cmd_ready(chip, flags);
> +		if (ret)
> +			goto out_locality;
> +
>   		ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
> +
> +		/* This may fail but do not override ret. */
> +		tpm_go_idle(chip, flags);
> +
> +out_locality:
> +		if (has_locality)
> +			tpm_relinquish_locality(chip, flags);

Safer to also put has_locality = false here ?


> +
> +		if (chip->ops->clk_enable != NULL)
> +			chip->ops->clk_enable(chip, false);
> +
> +		if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
> +		    !(flags & TPM_TRANSMIT_NESTED))
> +			mutex_unlock(&chip->tpm_mutex);
> +
>   		if (ret < 0)
>   			break;
>   		rc = be32_to_cpu(header->return_code);
Jarkko Sakkinen Nov. 6, 2018, 6:01 a.m. UTC | #2 
On Mon, Nov 05, 2018 at 05:20:33PM -0500, Stefan Berger wrote:
> > +out_locality:
> > +		if (has_locality)
> > +			tpm_relinquish_locality(chip, flags);
> 
> Safer to also put has_locality = false here ?

Not really sure why?

/Jarkko
diff mbox series

Patch

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index ecda6f96cde0..0f343407daf8 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -171,7 +171,6 @@  static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 	ssize_t len = 0;
 	u32 count, ordinal;
 	unsigned long stop;
-	bool need_locality;
 
 	rc = tpm_validate_command(chip, space, buf, bufsiz);
 	if (rc == -EINVAL)
@@ -201,30 +200,9 @@  static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 		return -E2BIG;
 	}
 
-	if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
-		mutex_lock(&chip->tpm_mutex);
-
-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, true);
-
-	/* Store the decision as chip->locality will be changed. */
-	need_locality = chip->locality == -1;
-
-	if (need_locality) {
-		rc = tpm_request_locality(chip, flags);
-		if (rc < 0) {
-			need_locality = false;
-			goto out_locality;
-		}
-	}
-
-	rc = tpm_cmd_ready(chip, flags);
-	if (rc)
-		goto out_locality;
-
 	rc = tpm2_prepare_space(chip, space, ordinal, buf);
 	if (rc)
-		goto out_idle;
+		return rc;
 
 	rc = chip->ops->send(chip, buf, count);
 	if (rc < 0) {
@@ -265,40 +243,16 @@  static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 		rc = len;
 		dev_err(&chip->dev,
 			"tpm_transmit: tpm_recv: error %d\n", rc);
-		goto out_idle;
-	} else if (len < TPM_HEADER_SIZE) {
-		rc = -EFAULT;
-		goto out_idle;
-	}
-
-	if (len != be32_to_cpu(header->length)) {
+		tpm2_flush_space(chip);
+	} else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
 		rc = -EFAULT;
-		goto out_idle;
-	}
 
 out_space:
-	if (rc) {
+	if (rc)
 		tpm2_flush_space(chip);
-	} else {
+	else
 		rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
-		if (rc)
-			dev_err(&chip->dev, "tpm2_commit_space: error %d\n",
-				rc);
-	}
-
-out_idle:
-	/* may fail but do not override previous error value in rc */
-	tpm_go_idle(chip, flags);
-
-out_locality:
-	if (need_locality)
-		tpm_relinquish_locality(chip, flags);
-
-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, false);
 
-	if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
-		mutex_unlock(&chip->tpm_mutex);
 	return rc ? rc : len;
 }
 
@@ -328,6 +282,7 @@  ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 	/* space for header and handles */
 	u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
 	unsigned int delay_msec = TPM2_DURATION_SHORT;
+	bool has_locality = false;
 	u32 rc = 0;
 	ssize_t ret;
 	const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
@@ -343,7 +298,40 @@  ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 	memcpy(save, buf, save_size);
 
 	for (;;) {
+		if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
+		    !(flags & TPM_TRANSMIT_NESTED))
+			mutex_lock(&chip->tpm_mutex);
+
+		if (chip->ops->clk_enable != NULL)
+			chip->ops->clk_enable(chip, true);
+
+		if (chip->locality == -1) {
+			ret = tpm_request_locality(chip, flags);
+			if (ret)
+				goto out_locality;
+			has_locality = true;
+		}
+
+		ret = tpm_cmd_ready(chip, flags);
+		if (ret)
+			goto out_locality;
+
 		ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
+
+		/* This may fail but do not override ret. */
+		tpm_go_idle(chip, flags);
+
+out_locality:
+		if (has_locality)
+			tpm_relinquish_locality(chip, flags);
+
+		if (chip->ops->clk_enable != NULL)
+			chip->ops->clk_enable(chip, false);
+
+		if (!(flags & TPM_TRANSMIT_UNLOCKED) &&
+		    !(flags & TPM_TRANSMIT_NESTED))
+			mutex_unlock(&chip->tpm_mutex);
+
 		if (ret < 0)
 			break;
 		rc = be32_to_cpu(header->return_code);