Make Smack operate on smack_known struct where it still used char*

Smack used to use a mix of smack_known struct and char* throughout its
APIs and implementation. This patch unifies the behaviour and makes it
store and operate exclusively on smack_known struct pointers when managing
labels.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

Conflicts:
	security/smack/smack_access.c
	security/smack/smack_lsm.c

4 files changed, 233 insertions, 255 deletions

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 2d13d5fb17ed..b828a379377c 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -71,11 +71,11 @@ struct smack_known {
 #define SMK_CIPSOLEN    24
 
 struct superblock_smack {
-        char            *smk_root;
-        char            *smk_floor;
-        char            *smk_hat;
-        char            *smk_default;
-        int             smk_initialized;
+        struct smack_known      *smk_root;
+        struct smack_known      *smk_floor;
+        struct smack_known      *smk_hat;
+        struct smack_known      *smk_default;
+        int                     smk_initialized;
 };
 
 struct socket_smack {
@@ -88,7 +88,7 @@ struct socket_smack {
  * Inode smack data
  */
 struct inode_smack {
-        char                    *smk_inode;     /* label of the fso */
+        struct smack_known      *smk_inode;     /* label of the fso */
         struct smack_known      *smk_task;      /* label of the task */
         struct smack_known      *smk_mmap;      /* label of the mmap domain */
         struct mutex            smk_lock;       /* initialization lock */
@@ -112,7 +112,7 @@ struct task_smack {
 struct smack_rule {
         struct list_head        list;
         struct smack_known      *smk_subject;
-        char                    *smk_object;
+        struct smack_known      *smk_object;
         int                     smk_access;
 };
 
@@ -123,7 +123,7 @@ struct smk_netlbladdr {
         struct list_head        list;
         struct sockaddr_in      smk_host;       /* network address */
         struct in_addr          smk_mask;       /* network mask */
-        char                    *smk_label;     /* label */
+        struct smack_known      *smk_label;     /* label */
 };
 
 /*
@@ -227,23 +227,23 @@ struct smk_audit_info {
 /*
  * These functions are in smack_lsm.c
  */
-struct inode_smack *new_inode_smack(char *);
+struct inode_smack *new_inode_smack(struct smack_known *);
 
 /*
  * These functions are in smack_access.c
  */
 int smk_access_entry(char *, char *, struct list_head *);
-int smk_access(struct smack_known *, char *, int, struct smk_audit_info *);
-int smk_tskacc(struct task_smack *, char *, u32, struct smk_audit_info *);
-int smk_curacc(char *, u32, struct smk_audit_info *);
+int smk_access(struct smack_known *, struct smack_known *,
+               int, struct smk_audit_info *);
+int smk_tskacc(struct task_smack *, struct smack_known *,
+               u32, struct smk_audit_info *);
+int smk_curacc(struct smack_known *, u32, struct smk_audit_info *);
 struct smack_known *smack_from_secid(const u32);
 char *smk_parse_smack(const char *string, int len);
 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);
-char *smk_import(const char *, int);
 struct smack_known *smk_import_entry(const char *, int);
 void smk_insert_entry(struct smack_known *skp);
 struct smack_known *smk_find_entry(const char *);
-u32 smack_to_secid(const char *);
 
 /*
  * Shared data.
@@ -253,7 +253,7 @@ extern int smack_cipso_mapped;
 extern struct smack_known *smack_net_ambient;
 extern struct smack_known *smack_onlycap;
 extern struct smack_known *smack_syslog_label;
-extern const char *smack_cipso_option;
+extern struct smack_known smack_cipso_option;
 extern int smack_ptrace_rule;
 
 extern struct smack_known smack_known_floor;
@@ -282,9 +282,9 @@ static inline int smk_inode_transmutable(const struct inode *isp)
 }
 
 /*
- * Present a pointer to the smack label in an inode blob.
+ * Present a pointer to the smack label entry in an inode blob.
  */
-static inline char *smk_of_inode(const struct inode *isp)
+static inline struct smack_known *smk_of_inode(const struct inode *isp)
 {
         struct inode_smack *sip = isp->i_security;
         return sip->smk_inode;
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 9f02cb0ac85e..5b970ffde024 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -94,7 +94,7 @@ int smk_access_entry(char *subject_label, char *object_label,
         struct smack_rule *srp;
 
         list_for_each_entry_rcu(srp, rule_list, list) {
-                if (srp->smk_object == object_label &&
+                if (srp->smk_object->smk_known == object_label &&
                     srp->smk_subject->smk_known == subject_label) {
                         may = srp->smk_access;
                         break;
@@ -111,8 +111,8 @@ int smk_access_entry(char *subject_label, char *object_label,
 
 /**
  * smk_access - determine if a subject has a specific access to an object
- * @subject_known: a pointer to the subject's Smack label entry
- * @object_label: a pointer to the object's Smack label
+ * @subject: a pointer to the subject's Smack label entry
+ * @object: a pointer to the object's Smack label entry
  * @request: the access requested, in "MAY" format
  * @a : a pointer to the audit data
  *
@@ -122,8 +122,8 @@ int smk_access_entry(char *subject_label, char *object_label,
  *
  * Smack labels are shared on smack_list
  */
-int smk_access(struct smack_known *subject_known, char *object_label,
-                int request, struct smk_audit_info *a)
+int smk_access(struct smack_known *subject, struct smack_known *object,
+               int request, struct smk_audit_info *a)
 {
         int may = MAY_NOT;
         int rc = 0;
@@ -133,7 +133,7 @@ int smk_access(struct smack_known *subject_known, char *object_label,
          *
          * A star subject can't access any object.
          */
-        if (subject_known == &smack_known_star) {
+        if (subject == &smack_known_star) {
                 rc = -EACCES;
                 goto out_audit;
         }
@@ -142,28 +142,28 @@ int smk_access(struct smack_known *subject_known, char *object_label,
          * Tasks cannot be assigned the internet label.
          * An internet subject can access any object.
          */
-        if (object_label == smack_known_web.smk_known ||
-            subject_known == &smack_known_web)
+        if (object == &smack_known_web ||
+            subject == &smack_known_web)
                 goto out_audit;
         /*
          * A star object can be accessed by any subject.
          */
-        if (object_label == smack_known_star.smk_known)
+        if (object == &smack_known_star)