[PATCH v7 4/5] ima: Use tpm_default_chip() and call TPM functions with a tpm_chip

Stefan Berger
2018-06-26T19:09:47Z

Rather than accessing the TPM functions by passing a NULL pointer for
the tpm_chip, which causes a lookup for a suitable chip every time, get a
hold of a tpm_chip and access the TPM functions using it.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_crypto.c | 2 +-
security/integrity/ima/ima_init.c | 11 ++++-------
security/integrity/ima/ima_queue.c | 2 +-
4 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 354bb5716ce3..35409461a3f2 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -56,6 +56,7 @@ extern int ima_policy_flag;
extern int ima_used_chip;
extern int ima_hash_algo;
extern int ima_appraise;
+extern struct tpm_chip *ima_tpm_chip;

/* IMA event related data */
struct ima_event_data {
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 4e085a17124f..88082f35adb2 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -634,7 +634,7 @@ static void __init ima_pcrread(int idx, u8 *pcr)
if (!ima_used_chip)
return;

- if (tpm_pcr_read(NULL, idx, pcr) != 0)
+ if (tpm_pcr_read(ima_tpm_chip, idx, pcr) != 0)
pr_err("Error Communicating to TPM chip\n");
}

diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 29b72cd2502e..1437ed3dbccc 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -27,6 +27,7 @@
/* name for boot aggregate entry */
static const char *boot_aggregate_name = "boot_aggregate";
int ima_used_chip;
+struct tpm_chip *ima_tpm_chip;

/* Add the boot aggregate to the IMA measurement list and extend
* the PCR register.
@@ -106,17 +107,13 @@ void __init ima_load_x509(void)

int __init ima_init(void)
{
- u8 pcr_i[TPM_DIGEST_SIZE];
int rc;

- ima_used_chip = 0;
- rc = tpm_pcr_read(NULL, 0, pcr_i);
- if (rc == 0)
- ima_used_chip = 1;
+ ima_tpm_chip = tpm_default_chip();

+ ima_used_chip = ima_tpm_chip != NULL;
if (!ima_used_chip)
- pr_info("No TPM chip found, activating TPM-bypass! (rc=%d)\n",
- rc);
+ pr_info("No TPM chip found, activating TPM-bypass!\n");

rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
if (rc)
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 418f35e38015..c6303fa19a49 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -145,7 +145,7 @@ static int ima_pcr_extend(const u8 *hash, int pcr)
if (!ima_used_chip)
return result;

- result = tpm_pcr_extend(NULL, pcr, hash);
+ result = tpm_pcr_extend(ima_tpm_chip, pcr, hash);
if (result != 0)
pr_err("Error Communicating to TPM chip, result: %d\n", result);
return result;
--
2.17.1