netlabel: Fix several rcu_dereference() calls used without RCU read locks

index 0bfeaab..06ab41b 100644
@@ -50,9 +50,12 @@ struct netlbl_domhsh_tbl {
 };
 
 /* Domain hash table */
-/* XXX - updates should be so rare that having one spinlock for the entire
- * hash table should be okay */
+/* updates should be so rare that having one spinlock for the entire hash table
+ * should be okay */
 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
+#define netlbl_domhsh_rcu_deref(p) \
+	rcu_dereference_check(p, rcu_read_lock_held() || \
+				 lockdep_is_held(&netlbl_domhsh_lock))
 static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
 static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
 

@@ -106,7 +109,8 @@ static void netlbl_domhsh_free_entry(struct rcu_head *entry)
  * Description:
  * This is the hashing function for the domain hash table, it returns the
  * correct bucket number for the domain.  The caller is responsibile for
- * calling the rcu_read_[un]lock() functions.
+ * ensuring that the hash table is protected with either a RCU read lock or the
+ * hash table lock.
  *
  */
 static u32 netlbl_domhsh_hash(const char *key)

@@ -120,7 +124,7 @@ static u32 netlbl_domhsh_hash(const char *key)
 
 	for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
 		val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
-	return val & (rcu_dereference(netlbl_domhsh)->size - 1);
+	return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
 }
 
 /**

@@ -130,7 +134,8 @@ static u32 netlbl_domhsh_hash(const char *key)
  * Description:
  * Searches the domain hash table and returns a pointer to the hash table
  * entry if found, otherwise NULL is returned.  The caller is responsibile for
- * the rcu hash table locks (i.e. the caller much call rcu_read_[un]lock()).
+ * ensuring that the hash table is protected with either a RCU read lock or the
+ * hash table lock.
  *
  */
 static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)

@@ -141,7 +146,7 @@ static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
 
 	if (domain != NULL) {
 		bkt = netlbl_domhsh_hash(domain);
-		bkt_list = &rcu_dereference(netlbl_domhsh)->tbl[bkt];
+		bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
 		list_for_each_entry_rcu(iter, bkt_list, list)
 			if (iter->valid && strcmp(iter->domain, domain) == 0)
 				return iter;

@@ -159,8 +164,8 @@ static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
  * Searches the domain hash table and returns a pointer to the hash table
  * entry if an exact match is found, if an exact match is not present in the
  * hash table then the default entry is returned if valid otherwise NULL is
- * returned.  The caller is responsibile for the rcu hash table locks
- * (i.e. the caller much call rcu_read_[un]lock()).
+ * returned.  The caller is responsibile ensuring that the hash table is
+ * protected with either a RCU read lock or the hash table lock.
  *
  */
 static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)

@@ -169,7 +174,7 @@ static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)
 
 	entry = netlbl_domhsh_search(domain);
 	if (entry == NULL) {
-		entry = rcu_dereference(netlbl_domhsh_def);
+		entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def);
 		if (entry != NULL && !entry->valid)
 			entry = NULL;
 	}

@@ -306,8 +311,11 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry,
 	struct netlbl_af6list *tmp6;
 #endif /* IPv6 */
 
+	/* XXX - we can remove this RCU read lock as the spinlock protects the
+	 *       entire function, but before we do we need to fixup the
+	 *       netlbl_af[4,6]list RCU functions to do "the right thing" with
+	 *       respect to rcu_dereference() when only a spinlock is held. */
 	rcu_read_lock();
-
 	spin_lock(&netlbl_domhsh_lock);
 	if (entry->domain != NULL)
 		entry_old = netlbl_domhsh_search(entry->domain);

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