apparmor: rework namespace free path

namespaces now completely use the unconfined profile to track the
refcount and rcu freeing cycle. So rework the code to simplify (track
everything through the profile path right up to the end), and move the
rcu_head from policy base to profile as the namespace no longer needs
it.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 0ceee96..aee2e71 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -329,30 +329,6 @@
 }
 
 /**
- * aa_free_namespace_rcu - free aa_namespace by rcu
- * @head: rcu_head callback for freeing of a profile  (NOT NULL)
- *
- * rcu_head is to the unconfined profile associated with the namespace
- */
-static void aa_free_namespace_rcu(struct rcu_head *head)
-{
-	struct aa_profile *p = container_of(head, struct aa_profile, base.rcu);
-	free_namespace(p->ns);
-}
-
-/**
- * aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace)
- * @kr: kref callback for freeing of a namespace  (NOT NULL)
- *
- * kref is to the unconfined profile associated with the namespace
- */
-void aa_free_namespace_kref(struct kref *kref)
-{
-	struct aa_profile *p = container_of(kref, struct aa_profile, count);
-	call_rcu(&p->base.rcu, aa_free_namespace_rcu);
-}
-
-/**
  * __aa_find_namespace - find a namespace on a list by @name
  * @head: list to search for namespace on  (NOT NULL)
  * @name: name of namespace to look for  (NOT NULL)
@@ -632,8 +608,11 @@
  */
 static void aa_free_profile_rcu(struct rcu_head *head)
 {
-	struct aa_profile *p = container_of(head, struct aa_profile, base.rcu);
-	free_profile(p);
+	struct aa_profile *p = container_of(head, struct aa_profile, rcu);
+	if (p->flags & PFLAG_NS_COUNT)
+		free_namespace(p->ns);
+	else
+		free_profile(p);
 }
 
 /**
@@ -643,7 +622,7 @@
 void aa_free_profile_kref(struct kref *kref)
 {
 	struct aa_profile *p = container_of(kref, struct aa_profile, count);
-	call_rcu(&p->base.rcu, aa_free_profile_rcu);
+	call_rcu(&p->rcu, aa_free_profile_rcu);
 }
 
 /**