On Fri Oct 25 19, Mimi Zohar wrote:
On Fri, 2019-10-25 at 07:28 -0700, Jerry Snitselaar wrote:
Easily determining what TCG version a tpm device implements
has been a pain point for userspace for a long time, so
add a sysfs file to report the tcg version of a tpm device.
Use "TCG" uppercase consistently.
Cc: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Cc: Peter Huewe <peterhuewe@xxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: linux-integrity@xxxxxxxxxxxxxxx
Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
thanks!
Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
FYI, on my system(s) the new file is accessible as
/sys/class/tpm/tpm0/version_major. Does this need to be documented
anywhere?
Yes, there should be an entry added to
Documentation/ABI/stable/sysfs-class-tpm.
I will fix that up and the TCG not being uppercase in a v2.
Should Documentation/ABI/stable/sysfs-class-tpm updated in
some way to reflect that those are all links under device
now and not actually there.
---
drivers/char/tpm/tpm-sysfs.c | 34 +++++++++++++++++++++++++++-------
1 file changed, 27 insertions(+), 7 deletions(-)
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index edfa89160010..9372c2d6f0b3 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -309,7 +309,17 @@ static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(timeouts);
-static struct attribute *tpm_dev_attrs[] = {
+static ssize_t major_version_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tpm_chip *chip = to_tpm_chip(dev);
+
+ return sprintf(buf, "%s\n", chip->flags & TPM_CHIP_FLAG_TPM2
+ ? "2.0" : "1.2");
+}
+static DEVICE_ATTR_RO(major_version);
+
+static struct attribute *tpm12_dev_attrs[] = {
&dev_attr_pubek.attr,
&dev_attr_pcrs.attr,
&dev_attr_enabled.attr,
@@ -320,18 +330,28 @@ static struct attribute *tpm_dev_attrs[] = {
&dev_attr_cancel.attr,
&dev_attr_durations.attr,
&dev_attr_timeouts.attr,
+ &dev_attr_major_version.attr,
NULL,
};
-static const struct attribute_group tpm_dev_group = {
- .attrs = tpm_dev_attrs,
+static struct attribute *tpm20_dev_attrs[] = {
+ &dev_attr_major_version.attr,
+ NULL
+};
+
+static const struct attribute_group tpm12_dev_group = {
+ .attrs = tpm12_dev_attrs,
+};
+
+static const struct attribute_group tpm20_dev_group = {
+ .attrs = tpm20_dev_attrs,
};
void tpm_sysfs_add_device(struct tpm_chip *chip)
{
- if (chip->flags & TPM_CHIP_FLAG_TPM2)
- return;
-
WARN_ON(chip->groups_cnt != 0);
- chip->groups[chip->groups_cnt++] = &tpm_dev_group;
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ chip->groups[chip->groups_cnt++] = &tpm20_dev_group;
+ else
+ chip->groups[chip->groups_cnt++] = &tpm12_dev_group;
}
