[PATCH v9 03/17] tpm: return 0 from pcrs_show() when tpm1_pcr_read() fails

Jarkko Sakkinen
2018-11-18T12:48:30Z

Do not print partial list of PCRs when tpm1_pcr_read() fails but instead
return 0 from pcrs_show(). This is consistent behavior with other sysfs
functions.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
---
drivers/char/tpm/tpm-sysfs.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 7ed7eb6f906a..928d4e839bb7 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -100,22 +100,21 @@ static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
{
cap_t cap;
u8 digest[TPM_DIGEST_SIZE];
- ssize_t rc;
u32 i, j, num_pcrs;
char *str = buf;
struct tpm_chip *chip = to_tpm_chip(dev);

- rc = tpm1_getcap(chip, TPM_CAP_PROP_PCR, &cap,
- "attempting to determine the number of PCRS",
- sizeof(cap.num_pcrs));
- if (rc)
+ if (tpm1_getcap(chip, TPM_CAP_PROP_PCR, &cap,
+ "attempting to determine the number of PCRS",
+ sizeof(cap.num_pcrs)))
return 0;

num_pcrs = be32_to_cpu(cap.num_pcrs);
for (i = 0; i < num_pcrs; i++) {
- rc = tpm1_pcr_read(chip, i, digest);
- if (rc)
+ if (tpm1_pcr_read(chip, i, digest)) {
+ str = buf;
break;
+ }
str += sprintf(str, "PCR-%02d: ", i);
for (j = 0; j < TPM_DIGEST_SIZE; j++)
str += sprintf(str, "%02X ", digest[j]);
--
2.19.1