Re: [PATCH] [73/275] tpm_tis: Use timeouts returned from TPM

From: Stefan Berger
Date: Wed Mar 30 2011 - 17:13:22 EST


On 03/30/2011 05:05 PM, Andi Kleen wrote:

Please drop it. It has been rejected previously. A revised patch has been sent.

Stefab

2.6.35-longterm review patch. If anyone has any objections, please let me know.

------------------
From: Stefan Berger<stefanb@xxxxxxxxxxxxxxxxxx>

commit 9b29050f8f75916f974a2d231ae5d3cd59792296 upstream.

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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andi Kleen<ak@xxxxxxxxxxxxxxx>
Tested-by: Guillaume Chazarain<guichaz@xxxxxxxxx>
Signed-off-by: Rajiv Andrade<srajiv@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman<gregkh@xxxxxxx>

---
drivers/char/tpm/tpm.c | 18 ++++++++++++++++--
drivers/char/tpm/tpm.h | 2 ++
drivers/char/tpm/tpm_tis.c | 4 +++-
3 files changed, 21 insertions(+), 3 deletions(-)

Index: linux-2.6.35.y/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.35.y.orig/drivers/char/tpm/tpm.c 2011-03-29 23:02:59.667308683 -0700
+++ linux-2.6.35.y/drivers/char/tpm/tpm.c 2011-03-29 23:02:59.685308223 -0700
@@ -567,9 +567,11 @@
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));
@@ -913,6 +915,18 @@
}
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: linux-2.6.35.y/drivers/char/tpm/tpm.h
===================================================================
--- linux-2.6.35.y.orig/drivers/char/tpm/tpm.h 2011-03-29 22:51:40.876677237 -0700
+++ linux-2.6.35.y/drivers/char/tpm/tpm.h 2011-03-29 23:02:59.685308223 -0700
@@ -56,6 +56,8 @@
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: linux-2.6.35.y/drivers/char/tpm/tpm_tis.c
===================================================================
--- linux-2.6.35.y.orig/drivers/char/tpm/tpm_tis.c 2011-03-29 22:51:40.877677211 -0700
+++ linux-2.6.35.y/drivers/char/tpm/tpm_tis.c 2011-03-29 23:02:59.686308198 -0700
@@ -355,6 +355,7 @@
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,
@@ -364,7 +365,8 @@
&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 = {

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