Re: [PATCH] tpm: improve output in sysfs files when the TPM fails

[Kylene Jo Hall]

On Fri, 2005-05-13 at 22:30 -0700, Andrew Morton wrote:
> Will this change permit unprivileged users to create large amounts of
> syslog output?  If so, this is considered poor form.
> 
> IOW: please confirm that the relevant sysfs files are root-read-only?
> 
Since after reconsideration this is more debug output than an error (the
TPM is operating correctly given the current state) I have changed the
statements to dbg rather than err.  Is this sufficient?  Also this patch
corrects a memory leak if the error path is taken in the tpm_show_pubek
function.

Thanks,
Kylie Hall

Signed-off-by: Kylene Hall <kjhall@xxxxxxxxxx>
---
--- linux-2.6.12-rc6-mm1/drivers/char/tpm/tpm.c.orig	2005-06-14 09:14:37.000000000 -0500
+++ linux-2.6.12-rc6-mm1/drivers/char/tpm/tpm.c	2005-06-14 09:24:23.000000000 -0500
@@ -147,7 +147,7 @@ ssize_t tpm_show_pcrs(struct device *dev
 	memcpy(data, cap_pcr, sizeof(cap_pcr));
 	if ((len = tpm_transmit(chip, data, sizeof(data)))
 	    < CAP_PCR_RESULT_SIZE) {
-		dev_err(&chip->pci_dev->dev, "A TPM error (%d) occurred "
+		dev_dbg(&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;
@@ -161,7 +161,7 @@ ssize_t tpm_show_pcrs(struct device *dev
 		memcpy(data + 10, &index, 4);
 		if ((len = tpm_transmit(chip, data, sizeof(data)))
 		    < READ_PCR_RESULT_SIZE){
-			dev_err(&chip->pci_dev->dev, "A TPM error (%d) occurred"
+			dev_dbg(&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;
@@ -205,10 +205,11 @@ ssize_t tpm_show_pubek(struct device *de
 
 	if ((len = tpm_transmit(chip, data, READ_PUBEK_RESULT_SIZE)) <
 	    READ_PUBEK_RESULT_SIZE) {
-		dev_err(&chip->pci_dev->dev, "A TPM error (%d) occurred "
+		dev_dbg(&chip->pci_dev->dev, "A TPM error (%d) occurred "
 				"attempting to read the PUBEK\n",
 			    be32_to_cpu(*((__be32 *) (data + 6))));
-		return 0;
+		rc = 0;
+		goto out;
 	}
 
 	/* 
@@ -240,6 +241,7 @@ ssize_t tpm_show_pubek(struct device *de
 			str += sprintf(str, "\n");
 	}
 	rc = str - buf;
+out:
 	kfree(data);
 	return rc;
 }


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