[PATCH v2 0/2] tpm: Unify send() callbacks

[PATCH v2 0/2] tpm: Unify send() callbacks

[Jarkko Sakkinen]

A portion of send() callbacks have returned length, in many cases just
returning back what was given as an argument, and tpm_crb has returned 0 on
success. This patch set fixes and unifies the behaviour.

v2:
The drivers tpm_nsc and tpm_infineon were forgotten. For this version I
checked both with find and command and from Kconfig that everything that is
supposed to be a driver directly interfacing with the TPM core, is included
(e.g. discluding tpm_tis_spi).

Jarkko Sakkinen (2):
  tpm: Unify the send callback behaviour
  tpm/tpm_i2c_atmel: Return -E2BIG when the transfer is incomplete

 drivers/char/tpm/st33zp24/st33zp24.c |  2 +-
 drivers/char/tpm/tpm_atmel.c         |  2 +-
 drivers/char/tpm/tpm_i2c_atmel.c     | 10 +++++++++-
 drivers/char/tpm/tpm_i2c_infineon.c  |  2 +-
 drivers/char/tpm/tpm_i2c_nuvoton.c   |  2 +-
 drivers/char/tpm/tpm_ibmvtpm.c       |  2 +-
 drivers/char/tpm/tpm_infineon.c      |  2 +-
 drivers/char/tpm/tpm_nsc.c           |  2 +-
 drivers/char/tpm/tpm_vtpm_proxy.c    |  3 +--
 drivers/char/tpm/xen-tpmfront.c      |  2 +-
 10 files changed, 18 insertions(+), 11 deletions(-)

-- 
2.19.1

[PATCH v2 1/2] tpm: Unify the send callback behaviour

[Jarkko Sakkinen]

The send() callback should never return length as it does not in every
driver except tpm_crb in the success case. The reason is that the main
transmit functionality only cares about whether the transmit was
successful or not and ignores the count completely.

Cc: stable@vger.kernel.org
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/st33zp24/st33zp24.c | 2 +-
 drivers/char/tpm/tpm_atmel.c         | 2 +-
 drivers/char/tpm/tpm_i2c_atmel.c     | 6 +++++-
 drivers/char/tpm/tpm_i2c_infineon.c  | 2 +-
 drivers/char/tpm/tpm_i2c_nuvoton.c   | 2 +-
 drivers/char/tpm/tpm_ibmvtpm.c       | 2 +-
 drivers/char/tpm/tpm_infineon.c      | 2 +-
 drivers/char/tpm/tpm_nsc.c           | 2 +-
 drivers/char/tpm/tpm_vtpm_proxy.c    | 3 +--
 drivers/char/tpm/xen-tpmfront.c      | 2 +-
 10 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c
index 64dc560859f2..13dc614b7ebc 100644
--- a/drivers/char/tpm/st33zp24/st33zp24.c
+++ b/drivers/char/tpm/st33zp24/st33zp24.c
@@ -436,7 +436,7 @@ static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
 			goto out_err;
 	}
 
-	return len;
+	return 0;
 out_err:
 	st33zp24_cancel(chip);
 	release_locality(chip);
diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c
index 66a14526aaf4..a290b30a0c35 100644
--- a/drivers/char/tpm/tpm_atmel.c
+++ b/drivers/char/tpm/tpm_atmel.c
@@ -105,7 +105,7 @@ static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
 		iowrite8(buf[i], priv->iobase);
 	}
 
-	return count;
+	return 0;
 }
 
 static void tpm_atml_cancel(struct tpm_chip *chip)
diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index 4720b2442ffe..aa11c8a1df5e 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c
@@ -65,7 +65,11 @@ static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	dev_dbg(&chip->dev,
 		"%s(buf=%*ph len=%0zx) -> sts=%d\n", __func__,
 		(int)min_t(size_t, 64, len), buf, len, status);
-	return status;
+
+	if (status < 0)
+		return status;
+
+	return 0;
 }
 
 static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
index 3b490d9d90e7..3b4e9672ff6c 100644
--- a/drivers/char/tpm/tpm_i2c_infineon.c
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -588,7 +588,7 @@ static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	/* go and do it */
 	iic_tpm_write(TPM_STS(tpm_dev.locality), &sts, 1);
 
-	return len;
+	return 0;
 out_err:
 	tpm_tis_i2c_ready(chip);
 	/* The TPM needs some time to clean up here,
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index 5700cc2ddee1..315a3b4548f7 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -465,7 +465,7 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	}
 
 	dev_dbg(dev, "%s() -> %zd\n", __func__, len);
-	return len;
+	return 0;
 }
 
 static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 07b5a487d0c8..aeae3222723c 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -192,7 +192,7 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
 		rc = 0;
 		ibmvtpm->tpm_processing_cmd = false;
 	} else
-		rc = count;
+		rc = 0;
 
 	spin_unlock(&ibmvtpm->rtce_lock);
 	return rc;
diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
index d8f10047fbba..97f6d4fe0aee 100644
--- a/drivers/char/tpm/tpm_infineon.c
+++ b/drivers/char/tpm/tpm_infineon.c
@@ -354,7 +354,7 @@ static int tpm_inf_send(struct tpm_chip *chip, u8 * buf, size_t count)
 	for (i = 0; i < count; i++) {
 		wait_and_send(chip, buf[i]);
 	}
-	return count;
+	return 0;
 }
 
 static void tpm_inf_cancel(struct tpm_chip *chip)
diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
index 5d6cce74cd3f..9bee3c5eb4bf 100644
--- a/drivers/char/tpm/tpm_nsc.c
+++ b/drivers/char/tpm/tpm_nsc.c
@@ -226,7 +226,7 @@ static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
 	}
 	outb(NSC_COMMAND_EOC, priv->base + NSC_COMMAND);
 
-	return count;
+	return 0;
 }
 
 static void tpm_nsc_cancel(struct tpm_chip *chip)
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 26a2be555288..d74f3de74ae6 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -335,7 +335,6 @@ static int vtpm_proxy_is_driver_command(struct tpm_chip *chip,
 static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
 {
 	struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
-	int rc = 0;
 
 	if (count > sizeof(proxy_dev->buffer)) {
 		dev_err(&chip->dev,
@@ -366,7 +365,7 @@ static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
 
 	wake_up_interruptible(&proxy_dev->wq);
 
-	return rc;
+	return 0;
 }
 
 static void vtpm_proxy_tpm_op_cancel(struct tpm_chip *chip)
diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
index 1259e935fd58..4e2d00cb0d81 100644
--- a/drivers/char/tpm/xen-tpmfront.c
+++ b/drivers/char/tpm/xen-tpmfront.c
@@ -173,7 +173,7 @@ static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
 		return -ETIME;
 	}
 
-	return count;
+	return 0;
 }
 
 static int vtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
-- 
2.19.1

[PATCH v2 2/2] tpm/tpm_i2c_atmel: Return -E2BIG when the transfer is incomplete

[Jarkko Sakkinen]

Return -E2BIG when the transfer is incomplete. The upper layer does
not retry, so not doing that is incorrect behaviour.

Cc: stable@vger.kernel.org
Fixes: a2871c62e186 ("tpm: Add support for Atmel I2C TPMs")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm_i2c_atmel.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index aa11c8a1df5e..8a7e80923091 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c
@@ -69,6 +69,10 @@ static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	if (status < 0)
 		return status;
 
+	/* The upper layer does not support incomplete sends. */
+	if (status != len)
+		return -E2BIG;
+
 	return 0;
 }
 
-- 
2.19.1

Re: [PATCH v2 0/2] tpm: Unify send() callbacks

[Stefan Berger]

On 2/8/19 11:03 AM, Jarkko Sakkinen wrote:
> A portion of send() callbacks have returned length, in many cases just
> returning back what was given as an argument, and tpm_crb has returned 0 on
> success. This patch set fixes and unifies the behaviour.
>
> v2:
> The drivers tpm_nsc and tpm_infineon were forgotten. For this version I
> checked both with find and command and from Kconfig that everything that is
> supposed to be a driver directly interfacing with the TPM core, is included
> (e.g. discluding tpm_tis_spi).


:-( st33zp24/i2c.c ends up calling i2c_master_send, which returns number 
of bytes written:

https://elixir.bootlin.com/linux/latest/source/include/linux/i2c.h#L108


>
> Jarkko Sakkinen (2):
>    tpm: Unify the send callback behaviour
>    tpm/tpm_i2c_atmel: Return -E2BIG when the transfer is incomplete
>
>   drivers/char/tpm/st33zp24/st33zp24.c |  2 +-
>   drivers/char/tpm/tpm_atmel.c         |  2 +-
>   drivers/char/tpm/tpm_i2c_atmel.c     | 10 +++++++++-
>   drivers/char/tpm/tpm_i2c_infineon.c  |  2 +-
>   drivers/char/tpm/tpm_i2c_nuvoton.c   |  2 +-
>   drivers/char/tpm/tpm_ibmvtpm.c       |  2 +-
>   drivers/char/tpm/tpm_infineon.c      |  2 +-
>   drivers/char/tpm/tpm_nsc.c           |  2 +-
>   drivers/char/tpm/tpm_vtpm_proxy.c    |  3 +--
>   drivers/char/tpm/xen-tpmfront.c      |  2 +-
>   10 files changed, 18 insertions(+), 11 deletions(-)
>

Re: [PATCH v2 0/2] tpm: Unify send() callbacks

[Jarkko Sakkinen]

On Fri, Feb 08, 2019 at 11:14:42AM -0500, Stefan Berger wrote:
> On 2/8/19 11:03 AM, Jarkko Sakkinen wrote:
> > A portion of send() callbacks have returned length, in many cases just
> > returning back what was given as an argument, and tpm_crb has returned 0 on
> > success. This patch set fixes and unifies the behaviour.
> > 
> > v2:
> > The drivers tpm_nsc and tpm_infineon were forgotten. For this version I
> > checked both with find and command and from Kconfig that everything that is
> > supposed to be a driver directly interfacing with the TPM core, is included
> > (e.g. discluding tpm_tis_spi).
> 
> 
> :-( st33zp24/i2c.c ends up calling i2c_master_send, which returns number of
> bytes written:
> 
> https://elixir.bootlin.com/linux/latest/source/include/linux/i2c.h#L108

And i2c.c is not a TPM driver so does it matter?

Then st33zp24_send() is the callback interfacing with the TPM core.

/Jarkko