tpm_tis: Use timeouts returned from TPM
authorStefan Berger <stefanb@linux.vnet.ibm.com>
Tue, 11 Jan 2011 19:37:29 +0000 (14:37 -0500)
committerRajiv Andrade <srajiv@linux.vnet.ibm.com>
Fri, 11 Feb 2011 03:30:50 +0000 (01:30 -0200)
The current TPM TIS driver in git discards the timeout values returned
from the TPM. The check of the response packet needs to consider that
the return_code field is 0 on success and the size of the expected
packet is equivalent to the header size + u32 length indicator for the
TPM_GetCapability() result + 3 timeout indicators of type u32.

I am also adding a sysfs entry 'timeouts' showing the timeouts that are
being used.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
drivers/char/tpm/tpm.c
drivers/char/tpm/tpm.h
drivers/char/tpm/tpm_tis.c

index 36e0fa1..faf5a2c 100644 (file)
@@ -577,9 +577,11 @@ duration:
        if (rc)
                return;
 
-       if (be32_to_cpu(tpm_cmd.header.out.return_code)
-           != 3 * sizeof(u32))
+       if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
+           be32_to_cpu(tpm_cmd.header.out.length)
+           != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
                return;
+
        duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
        chip->vendor.duration[TPM_SHORT] =
            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
@@ -939,6 +941,18 @@ ssize_t tpm_show_caps_1_2(struct device * dev,
 }
 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
 
+ssize_t tpm_show_timeouts(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+       struct tpm_chip *chip = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%d %d %d\n",
+                      jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
+                      jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
+                      jiffies_to_usecs(chip->vendor.duration[TPM_LONG]));
+}
+EXPORT_SYMBOL_GPL(tpm_show_timeouts);
+
 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
                        const char *buf, size_t count)
 {
index 72ddb03..d84ff77 100644 (file)
@@ -56,6 +56,8 @@ extern ssize_t tpm_show_owned(struct device *, struct device_attribute *attr,
                                char *);
 extern ssize_t tpm_show_temp_deactivated(struct device *,
                                         struct device_attribute *attr, char *);
+extern ssize_t tpm_show_timeouts(struct device *,
+                                struct device_attribute *attr, char *);
 
 struct tpm_chip;
 
index dd21df5..0d1d38e 100644 (file)
@@ -376,6 +376,7 @@ static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated,
                   NULL);
 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps_1_2, NULL);
 static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
+static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL);
 
 static struct attribute *tis_attrs[] = {
        &dev_attr_pubek.attr,
@@ -385,7 +386,8 @@ static struct attribute *tis_attrs[] = {
        &dev_attr_owned.attr,
        &dev_attr_temp_deactivated.attr,
        &dev_attr_caps.attr,
-       &dev_attr_cancel.attr, NULL,
+       &dev_attr_cancel.attr,
+       &dev_attr_timeouts.attr, NULL,
 };
 
 static struct attribute_group tis_attr_grp = {