security: smack: add kmem_cache for smack_master_list allocations

On ARM, sizeof(struct smack_master_list) == 12. Allocation by kmalloc() uses a32-byte-long chunk to allocate 12 bytes. Just ask ksize(). It means that 63%of memory is simply wasted for padding bytes.
The problem is fixed in this patch by using kmem_cache. The cache allocatesstruct smack_master_list using 16-byte-long chunks according to ksize(). Thisreduces amount of used memory by 50%.

Change-Id: I61562995c68f63e5e728656c4af7732ece403bf4
Signed-off-by: jooseong.lee <jooseong.lee@samsung.com>

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 45aa224b91ae4201da293e91566608873716acfc..7b912f552cacea74c160536a697ced3e84d5302b 100644 (file)
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -223,6 +223,12 @@ struct smk_audit_info {
        struct smack_audit_data sad;
 #endif
 };
+
+struct smack_master_list {
+       struct list_head        list;
+       struct smack_rule       *smk_rule;
+};
+
 /*
  * These functions are in smack_lsm.c
  */
@@ -268,6 +274,7 @@ extern struct list_head smk_netlbladdr_list;
 
 /* Cache for fast and thrifty allocations */
 extern struct kmem_cache *smack_rule_cache;
+extern struct kmem_cache *smack_master_list_cache;
 
 extern struct security_operations smack_ops;
 

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 523e106a274ccb9fafecdfdbfe4deea56f2c0075..df3f6035c622044ae8f8f6211b80541524738d15 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4018,6 +4018,7 @@ static __init void init_smack_known_list(void)
 
 /* KMEM caches for fast and thrifty allocations */
 struct kmem_cache *smack_rule_cache;
+struct kmem_cache *smack_master_list_cache;
 
 /**
  * smack_init - initialize the smack system
@@ -4036,9 +4037,16 @@ static __init int smack_init(void)
        if (!smack_rule_cache)
                return -ENOMEM;
 
+       smack_master_list_cache = KMEM_CACHE(smack_master_list, 0);
+       if (!smack_master_list_cache) {
+               kmem_cache_destroy(smack_rule_cache);
+               return -ENOMEM;
+       }
+
        tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
                                GFP_KERNEL);
        if (tsp == NULL) {
+               kmem_cache_destroy(smack_master_list_cache);
                kmem_cache_destroy(smack_rule_cache);
                return -ENOMEM;
        }

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index e602a34bf7e1e2480f101a3ce74f5cc6ab1cd2fe..39af4bf3f29a2714adf3274c1924b773daf9eb03 100644 (file)
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -122,11 +122,6 @@ LIST_HEAD(smk_netlbladdr_list);
  * Rule lists are maintained for each label.
  * This master list is just for reading /smack/load and /smack/load2.
  */
-struct smack_master_list {
-       struct list_head        list;
-       struct smack_rule       *smk_rule;
-};
-
 LIST_HEAD(smack_rule_list);
 
 struct smack_parsed_rule {
@@ -251,7 +246,8 @@ static int smk_set_access(struct smack_parsed_rule *srp,
                 * it needs to get added for reporting.
                 */
                if (global) {
-                       smlp = kzalloc(sizeof(*smlp), GFP_KERNEL);
+                       smlp = kmem_cache_zalloc(smack_master_list_cache,
+                                                       GFP_KERNEL);
                        if (smlp != NULL) {
                                smlp->smk_rule = sp;
                                list_add_rcu(&smlp->list, &smack_rule_list);