The TPM TIS specification says the TPM signals the acquisition of
locality when the TMP_ACCESS_REQUEST_USE bit goes to one *and* the
TPM_ACCESS_REQUEST_USE bit goes to zero. Currently we only check the
former not the latter, so check both. Adding the check on
TPM_ACCESS_REQUEST_USE should fix the case where the locality is
re-requested before the TPM has released it. In this case the
locality may get released briefly before it is reacquired, which
causes all sorts of problems. However, with the added check,
TPM_ACCESS_REQUEST_USE should remain 1 until the second request for
the locality is granted.
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
---
v2: added this patch
---
drivers/char/tpm/tpm_tis_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 92c51c6cfd1b..f3ecde8df47d 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -125,7 +125,8 @@ static bool check_locality(struct tpm_chip *chip, int l)
if (rc < 0)
return false;
- if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+ if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID
+ | TPM_ACCESS_REQUEST_USE)) ==
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
priv->locality = l;
return true;
--
2.28.0
