ima: check ima_policy_flag in the ima_file_free() hook

This patch completes the switching to the 'ima_policy_flag' variable
in the checks at the beginning of IMA functions, starting with the
commit a756024e.

Checking 'iint_initialized' is completely unnecessary, because
S_IMA flag is unset if iint was not allocated. At the same time
the integrity cache is allocated with SLAB_PANIC and the kernel will
panic if the allocation fails during kernel initialization. So on
a running system iint_initialized is always true and can be removed.

Changes in v3:
* not limiting test to IMA_APPRAISE (spotted by Roberto Sassu)

Changes in v2:
* 'iint_initialized' removal patch merged to this patch (requested
   by Mimi)

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: Roberto Sassu <roberto.sassu@polito.it>

security/integrity/iint.c

@@ -25,8 +25,6 @@ static struct rb_root integrity_iint_tree = RB_ROOT;
 static DEFINE_RWLOCK(integrity_iint_lock);
 static struct kmem_cache *iint_cache __read_mostly;
 
-int iint_initialized;
-
 /*
  * __integrity_iint_find - return the iint associated with an inode
  */
@@ -166,7 +164,6 @@ static int __init integrity_iintcache_init(void)
 	iint_cache =
 	    kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
 			      0, SLAB_PANIC, init_once);
-	iint_initialized = 1;
 	return 0;
 }
 security_initcall(integrity_iintcache_init);

security/integrity/ima/ima_main.c

@@ -143,7 +143,7 @@ void ima_file_free(struct file *file)
 	struct inode *inode = file_inode(file);
 	struct integrity_iint_cache *iint;
 
-	if (!iint_initialized || !S_ISREG(inode->i_mode))
+	if (!ima_policy_flag || !S_ISREG(inode->i_mode))
 		return;
 
 	iint = integrity_iint_find(inode);

security/integrity/integrity.h

@@ -169,6 +169,3 @@ static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
 {
 }
 #endif
-
-/* set during initialization */
-extern int iint_initialized;