diff options
| author | Jerry Snitselaar <jsnitsel@redhat.com> | 2018-05-05 12:54:53 -0700 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> | 2018-05-14 13:28:31 +0300 |
| commit | 33bafe90824bc9584fad535410bebc1fbe382fdf (patch) | |
| tree | 11cbc8b6f638f3d98c794b75c20a1c05a3f336f7 /drivers/char | |
| parent | 1fbad3028664e114d210dc65d768947a3a553eaa (diff) | |
| download | linux-33bafe90824bc9584fad535410bebc1fbe382fdf.tar.bz2 | |
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: Laurent Bigonville <bigon@debian.org>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Laurent Bigonville <bigon@debian.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tpm/tpm_tis_core.c | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 5a1f47b43947..d547cd309dbd 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -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); - return 0; + 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) |