tpm: return 0 from pcrs_show() when tpm1_pcr_read() fails

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>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 7ed7eb6..928d4e8 100644 (file)
--- 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]);