[PATCH v2 4/4] ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

Get rid of ima_used_chip and use ima_tpm_chip variable instead for
determining whether to use the TPM chip.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
---
 security/integrity/ima/ima.h        | 1 -
 security/integrity/ima/ima_crypto.c | 2 +-
 security/integrity/ima/ima_init.c   | 7 ++-----
 security/integrity/ima/ima_queue.c  | 2 +-
 4 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 53a88d578ca5..18491c0e9b97 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -54,7 +54,6 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
 extern int ima_policy_flag;
 
 /* set during initialization */
-extern int ima_used_chip;
 extern int ima_hash_algo;
 extern int ima_appraise;
 extern struct rw_semaphore ima_tpm_chip_lock;
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index da7715240476..bc6ad6b3243a 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -635,7 +635,7 @@ static void __init ima_pcrread(int idx, u8 *pcr)
 
 	down_read(&ima_tpm_chip_lock);
 
-	if (!ima_used_chip)
+	if (!ima_tpm_chip)
 		goto out;
 
 	result = tpm_pcr_read(ima_tpm_chip, idx, pcr);
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 24db06c4f463..84fba44c4415 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -27,7 +27,6 @@
 
 /* name for boot aggregate entry */
 static const char *boot_aggregate_name = "boot_aggregate";
-int ima_used_chip;
 struct rw_semaphore ima_tpm_chip_lock = __RWSEM_INITIALIZER(ima_tpm_chip_lock);
 struct tpm_chip *ima_tpm_chip;
 
@@ -67,7 +66,7 @@ static int __init ima_add_boot_aggregate(void)
 	iint->ima_hash->algo = HASH_ALGO_SHA1;
 	iint->ima_hash->length = SHA1_DIGEST_SIZE;
 
-	if (ima_used_chip) {
+	if (ima_tpm_chip) {
 		result = ima_calc_boot_aggregate(&hash.hdr);
 		if (result < 0) {
 			audit_cause = "hashing_error";
@@ -114,7 +113,6 @@ static int ima_shutdown(struct notifier_block *this, unsigned long action,
 	if (ima_tpm_chip) {
 		tpm_chip_put(ima_tpm_chip);
 		ima_tpm_chip = NULL;
-		ima_used_chip = 0;
 	}
 	up_write(&ima_tpm_chip_lock);
 	return NOTIFY_DONE;
@@ -133,8 +131,7 @@ int __init ima_init(void)
 
 	ima_tpm_chip = tpm_chip_find();
 
-	ima_used_chip = (ima_tpm_chip != NULL);
-	if (!ima_used_chip)
+	if (!ima_tpm_chip)
 		pr_info("No TPM chip found, activating TPM-bypass!\n");
 
 	rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 6c9427939a28..591ff3d76fe6 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -143,7 +143,7 @@ static int ima_pcr_extend(const u8 *hash, int pcr)
 	int result = 0;
 
 	down_read(&ima_tpm_chip_lock);
-	if (!ima_used_chip)
+	if (!ima_tpm_chip)
 		goto out;
 
 	result = tpm_pcr_extend(ima_tpm_chip, pcr, hash);
-- 
2.13.6