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authorPeter Huewe <peterhuewe@gmx.de>2016-10-11 15:01:01 +0300
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2016-11-28 01:31:30 +0200
commit2c97f6f20cb193264360067259029892c70ce63f (patch)
treebe45d5b5a8d0ec44474c1a82813e6d32de1e3d9c /drivers/char
parente74f2f76c13770bb8e004475a933923e9c92723d (diff)
downloadop-kernel-dev-2c97f6f20cb193264360067259029892c70ce63f.zip
op-kernel-dev-2c97f6f20cb193264360067259029892c70ce63f.tar.gz
char/tpm: Check return code of wait_for_tpm_stat
In some weird cases it might be possible that the TPM does not set STS.VALID within the given timeout time (or ever) but sets STS.EXPECT (STS=0x0C) In this case the driver gets stuck in the while loop of tpm_tis_send_data and loops endlessly. Checking the return value of wait_for_tpm_stat fixes this and the driver bails out correctly. While at it fixing all other users since if the TPM does not manage to set STS.VALID within the reasonable timeframe something is definitely wrong and the driver should react correctly. Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-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.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index e3bf31b..73f4c4b 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -180,11 +180,13 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int size = 0, burstcnt, rc;
- while (size < count &&
- wait_for_tpm_stat(chip,
+ while (size < count) {
+ rc = wait_for_tpm_stat(chip,
TPM_STS_DATA_AVAIL | TPM_STS_VALID,
chip->timeout_c,
- &priv->read_queue, true) == 0) {
+ &priv->read_queue, true);
+ if (rc < 0)
+ return rc;
burstcnt = min_t(int, get_burstcount(chip), count - size);
rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
@@ -229,8 +231,11 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
goto out;
}
- wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
- &priv->int_queue, false);
+ if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+ &priv->int_queue, false) < 0) {
+ size = -ETIME;
+ goto out;
+ }
status = tpm_tis_status(chip);
if (status & TPM_STS_DATA_AVAIL) { /* retry? */
dev_err(&chip->dev, "Error left over data\n");
@@ -279,8 +284,11 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
count += burstcnt;
- wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
- &priv->int_queue, false);
+ if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+ &priv->int_queue, false) < 0) {
+ rc = -ETIME;
+ goto out_err;
+ }
status = tpm_tis_status(chip);
if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
rc = -EIO;
@@ -293,8 +301,11 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
if (rc < 0)
goto out_err;
- wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
- &priv->int_queue, false);
+ if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+ &priv->int_queue, false) < 0) {
+ rc = -ETIME;
+ goto out_err;
+ }
status = tpm_tis_status(chip);
if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
rc = -EIO;
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