Re: [PATCH v3 03/16] tpm: return 0 from pcrs_show() when tpm1_pcr_read() fails

[Stefan Berger]

On 11/4/18 8:45 PM, Jarkko Sakkinen wrote:
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.sakki...@linux.intel.com>
---
  drivers/char/tpm/tpm-sysfs.c | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 7ed7eb6f906a..d3b05c7526c8 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -115,13 +115,15 @@ static ssize_t pcrs_show(struct device *dev, struct 
device_attribute *attr,
        for (i = 0; i < num_pcrs; i++) {
                rc = tpm1_pcr_read(chip, i, digest);
                if (rc)
-                       break;
+                       goto out;

Previous patch said "Return zero when tpm_buf_init() fails as we do for 
other functions in tpm-sysfs.c.". Why not return 0 in this case as well?


                str += sprintf(str, "PCR-%02d: ", i);
                for (j = 0; j < TPM_DIGEST_SIZE; j++)
                        str += sprintf(str, "%02X ", digest[j]);
                str += sprintf(str, "\n");
        }
-       return str - buf;
+       rc = str - buf;
+out:
+       return rc;
  }
  static DEVICE_ATTR_RO(pcrs);