[PATCH] tpm: add debugging output

Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 8 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 726d1b5b33b0..785dce67942f 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -146,8 +146,12 @@ ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 
         memcpy(data, cap_pcr, sizeof(cap_pcr));
         if ((len = tpm_transmit(chip, data, sizeof(data)))
-            < CAP_PCR_RESULT_SIZE)
-                return len;
+            < CAP_PCR_RESULT_SIZE) {
+                dev_err(&chip->pci_dev->dev, "A TPM error (%d) occurred "
+                                "attempting to determine the number of PCRS\n",
+                        be32_to_cpu(*((__be32 *) (data + 6))));
+                return 0;
+        }
 
         num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
 
@@ -156,16 +160,20 @@ ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
                 index = cpu_to_be32(i);
                 memcpy(data + 10, &index, 4);
                 if ((len = tpm_transmit(chip, data, sizeof(data)))
-                    < READ_PCR_RESULT_SIZE)
-                        return len;
+                    < READ_PCR_RESULT_SIZE){
+                        dev_err(&chip->pci_dev->dev, "A TPM error (%d) occurred"
+                                " attempting to read PCR %d of %d\n",
+                                be32_to_cpu(*((__be32 *) (data + 6))), i, num_pcrs);
+                        goto out;
+                }
                 str += sprintf(str, "PCR-%02d: ", i);
                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
                         str += sprintf(str, "%02X ", *(data + 10 + j));
                 str += sprintf(str, "\n");
         }
+out:
         return str - buf;
 }
-
 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 
 #define  READ_PUBEK_RESULT_SIZE 314
@@ -197,8 +205,10 @@ ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 
         if ((len = tpm_transmit(chip, data, READ_PUBEK_RESULT_SIZE)) <
             READ_PUBEK_RESULT_SIZE) {
-                rc = len;
-                goto out;
+                dev_err(&chip->pci_dev->dev, "A TPM error (%d) occurred "
+                                "attempting to read the PUBEK\n",
+                            be32_to_cpu(*((__be32 *) (data + 6))));
+                return 0;
         }
 
         /* 
@@ -230,7 +240,6 @@ ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
                         str += sprintf(str, "\n");
         }
         rc = str - buf;
-out:
         kfree(data);
         return rc;
 }