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authorJerry Snitselaar <jsnitsel@redhat.com>2018-05-05 12:54:53 -0700
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2018-05-14 13:28:31 +0300
commit33bafe90824bc9584fad535410bebc1fbe382fdf (patch)
tree11cbc8b6f638f3d98c794b75c20a1c05a3f336f7 /drivers/char
parent1fbad3028664e114d210dc65d768947a3a553eaa (diff)
downloadlinux-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.c47
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)