diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tpm/tpm_tis_core.c | 11 | ||||
| -rw-r--r-- | drivers/char/tpm/tpm_tis_core.h | 1 |
2 files changed, 12 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 65ab1b027949..92c51c6cfd1b 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -239,6 +239,17 @@ static u8 tpm_tis_status(struct tpm_chip *chip) if (rc < 0) return 0; + if (unlikely((status & TPM_STS_READ_ZERO) != 0)) { + /* + * If this trips, the chances are the read is + * returning 0xff because the locality hasn't been + * acquired. Usually because tpm_try_get_ops() hasn't + * been called before doing a TPM operation. + */ + WARN_ONCE(1, "TPM returned invalid status\n"); + return 0; + } + return status; } diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 7337819f5d7b..9b2d32a59f67 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -34,6 +34,7 @@ enum tis_status { TPM_STS_GO = 0x20, TPM_STS_DATA_AVAIL = 0x10, TPM_STS_DATA_EXPECT = 0x08, + TPM_STS_READ_ZERO = 0x23, /* bits that must be zero on read */ }; enum tis_int_flags { |