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Commit 33bafe90 authored by Jerry Snitselaar's avatar Jerry Snitselaar Committed by Jarkko Sakkinen
Browse files

tpm_tis: verify locality released before returning from release_locality 



For certain tpm chips releasing locality can take long enough that a
subsequent call to request_locality will see the locality as being active
when the access register is read in check_locality. So check that the
locality has been released before returning from release_locality.

Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Reported-by: default avatarLaurent Bigonville <bigon@debian.org>
Signed-off-by: default avatarJerry Snitselaar <jsnitsel@redhat.com>
Tested-by: default avatarLaurent Bigonville <bigon@debian.org>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
parent 1fbad302

drivers/char/tpm/tpm_tis_core.c

+46 −1
Original line number Diff line number Diff line
@@ -143,13 +143,58 @@ static bool check_locality(struct tpm_chip *chip, int l) 
	return false;

}



static bool locality_inactive(struct tpm_chip *chip, int l)

{

	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);

	int rc;

	u8 access;



	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);

	if (rc < 0)

		return false;



	if ((access & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY))

	    == TPM_ACCESS_VALID)

		return true;



	return false;

}



static int release_locality(struct tpm_chip *chip, int l)

{

	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);

	unsigned long stop, timeout;

	long rc;



	tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);



	stop = jiffies + chip->timeout_a;



	if (chip->flags & TPM_CHIP_FLAG_IRQ) {

again:

		timeout = stop - jiffies;

		if ((long)timeout <= 0)

			return -1;



		rc = wait_event_interruptible_timeout(priv->int_queue,

						      (locality_inactive(chip, l)),

						      timeout);



		if (rc > 0)

			return 0;



		if (rc == -ERESTARTSYS && freezing(current)) {

			clear_thread_flag(TIF_SIGPENDING);

			goto again;

		}

	} else {

		do {

			if (locality_inactive(chip, l))

				return 0;

			tpm_msleep(TPM_TIMEOUT);

		} while (time_before(jiffies, stop));

	}

	return -1;

}



static int request_locality(struct tpm_chip *chip, int l)