[PATCH v2] tpm: Remove duplicate code from caps_show() in tpm-sysfs.c

From: Jarkko Sakkinen
Date: Mon Sep 02 2019 - 09:31:44 EST


Replace existing TPM 1.x version structs with new structs that consolidate
the common parts into a single struct so that code duplication is no longer
needed in caps_show().

Cc: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
v2: Give back the TPM 1.1 version only if tpm1_getcap() returns 0.
drivers/char/tpm/tpm-sysfs.c | 45 ++++++++++++++++++------------------
drivers/char/tpm/tpm.h | 23 ++++++++----------
2 files changed, 33 insertions(+), 35 deletions(-)

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index edfa89160010..3b53b3e5ec3e 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -217,6 +217,7 @@ static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tpm_chip *chip = to_tpm_chip(dev);
+ struct tpm1_version *version;
ssize_t rc = 0;
char *str = buf;
cap_t cap;
@@ -232,31 +233,31 @@ static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
str += sprintf(str, "Manufacturer: 0x%x\n",
be32_to_cpu(cap.manufacturer_id));

- /* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
- rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
+ /* TPM 1.2 */
+ if (!tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
"attempting to determine the 1.2 version",
- sizeof(cap.tpm_version_1_2));
- if (!rc) {
- str += sprintf(str,
- "TCG version: %d.%d\nFirmware version: %d.%d\n",
- cap.tpm_version_1_2.Major,
- cap.tpm_version_1_2.Minor,
- cap.tpm_version_1_2.revMajor,
- cap.tpm_version_1_2.revMinor);
- } else {
- /* Otherwise just use TPM_STRUCT_VER */
- if (tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
- "attempting to determine the 1.1 version",
- sizeof(cap.tpm_version)))
- goto out_ops;
- str += sprintf(str,
- "TCG version: %d.%d\nFirmware version: %d.%d\n",
- cap.tpm_version.Major,
- cap.tpm_version.Minor,
- cap.tpm_version.revMajor,
- cap.tpm_version.revMinor);
+ sizeof(cap.version2))) {
+ version = &cap.version2.version;
+ goto out_print;
}
+
+ /* TPM 1.1 */
+ if (tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
+ "attempting to determine the 1.1 version",
+ sizeof(cap.version1))) {
+ goto out_ops;
+ }
+
+ version = &cap.version1;
+
+out_print:
+ str += sprintf(str,
+ "TCG version: %d.%d\nFirmware version: %d.%d\n",
+ version->major, version->minor,
+ version->rev_major, version->rev_minor);
+
rc = str - buf;
+
out_ops:
tpm_put_ops(chip);
return rc;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index a7fea3e0ca86..a4f74dd02a35 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -186,19 +186,16 @@ struct stclear_flags_t {
u8 bGlobalLock;
} __packed;

-struct tpm_version_t {
- u8 Major;
- u8 Minor;
- u8 revMajor;
- u8 revMinor;
+struct tpm1_version {
+ u8 major;
+ u8 minor;
+ u8 rev_major;
+ u8 rev_minor;
} __packed;

-struct tpm_version_1_2_t {
- __be16 tag;
- u8 Major;
- u8 Minor;
- u8 revMajor;
- u8 revMinor;
+struct tpm1_version2 {
+ __be16 tag;
+ struct tpm1_version version;
} __packed;

struct timeout_t {
@@ -243,8 +240,8 @@ typedef union {
struct stclear_flags_t stclear_flags;
__u8 owned;
__be32 num_pcrs;
- struct tpm_version_t tpm_version;
- struct tpm_version_1_2_t tpm_version_1_2;
+ struct tpm1_version version1;
+ struct tpm1_version2 version2;
__be32 manufacturer_id;
struct timeout_t timeout;
struct duration_t duration;
--
2.20.1