batman-adv: protect originator nodes with reference counters

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

1 files changed, 52 insertions, 9 deletions

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 5c32314f8279..fcdb0b7fe586 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -103,12 +103,13 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
         return neigh_node;
 }
 
-static void free_orig_node(void *data, void *arg)
+void orig_node_free_ref(struct kref *refcount)
 {
         struct hlist_node *node, *node_tmp;
         struct neigh_node *neigh_node;
-        struct orig_node *orig_node = (struct orig_node *)data;
-        struct bat_priv *bat_priv = (struct bat_priv *)arg;
+        struct orig_node *orig_node;
+
+        orig_node = container_of(refcount, struct orig_node, refcount);
 
         spin_lock_bh(&orig_node->neigh_list_lock);
 
@@ -122,7 +123,8 @@ static void free_orig_node(void *data, void *arg)
         spin_unlock_bh(&orig_node->neigh_list_lock);
 
         frag_list_free(&orig_node->frag_list);
-        hna_global_del_orig(bat_priv, orig_node, "originator timed out");
+        hna_global_del_orig(orig_node->bat_priv, orig_node,
+                            "originator timed out");
 
         kfree(orig_node->bcast_own);
         kfree(orig_node->bcast_own_sum);
@@ -131,17 +133,53 @@ static void free_orig_node(void *data, void *arg)
 
 void originator_free(struct bat_priv *bat_priv)
 {
-        if (!bat_priv->orig_hash)
+        struct hashtable_t *hash = bat_priv->orig_hash;
+        struct hlist_node *walk, *safe;
+        struct hlist_head *head;
+        struct element_t *bucket;
+        spinlock_t *list_lock; /* spinlock to protect write access */
+        struct orig_node *orig_node;
+        int i;
+
+        if (!hash)
                 return;
 
         cancel_delayed_work_sync(&bat_priv->orig_work);
 
         spin_lock_bh(&bat_priv->orig_hash_lock);
-        hash_delete(bat_priv->orig_hash, free_orig_node, bat_priv);
         bat_priv->orig_hash = NULL;
+
+        for (i = 0; i < hash->size; i++) {
+                head = &hash->table[i];
+                list_lock = &hash->list_locks[i];
+
+                spin_lock_bh(list_lock);
+                hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
+                        orig_node = bucket->data;
+
+                        hlist_del_rcu(walk);
+                        call_rcu(&bucket->rcu, bucket_free_rcu);
+                        kref_put(&orig_node->refcount, orig_node_free_ref);
+                }
+                spin_unlock_bh(list_lock);
+        }
+
+        hash_destroy(hash);
         spin_unlock_bh(&bat_priv->orig_hash_lock);
 }
 
+static void bucket_free_orig_rcu(struct rcu_head *rcu)
+{
+        struct element_t *bucket;
+        struct orig_node *orig_node;
+
+        bucket = container_of(rcu, struct element_t, rcu);
+        orig_node = bucket->data;
+
+        kref_put(&orig_node->refcount, orig_node_free_ref);
+        kfree(bucket);
+}
+
 /* this function finds or creates an originator entry for the given
  * address if it does not exits */
 struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
@@ -156,8 +194,10 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
                                                    addr));
         rcu_read_unlock();
 
-        if (orig_node)
+        if (orig_node) {
+                kref_get(&orig_node->refcount);
                 return orig_node;
+        }
 
         bat_dbg(DBG_BATMAN, bat_priv,
                 "Creating new originator: %pM\n", addr);
@@ -168,7 +208,9 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
 
         INIT_HLIST_HEAD(&orig_node->neigh_list);
         spin_lock_init(&orig_node->neigh_list_lock);
+        kref_init(&orig_node->refcount);
 
+        orig_node->bat_priv = bat_priv;
         memcpy(orig_node->orig, addr, ETH_ALEN);
         orig_node->router = NULL;
         orig_node->hna_buff = NULL;
@@ -197,6 +239,8 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
         if (hash_added < 0)
                 goto free_bcast_own_sum;
 
+        /* extra reference for return */
+        kref_get(&orig_node->refcount);
         return orig_node;
 free_bcast_own_sum:
         kfree(orig_node->bcast_own_sum);
@@ -318,8 +362,7 @@ static void _purge_orig(struct bat_priv *bat_priv)
                                 if (orig_node->gw_flags)
                                         gw_node_delete(bat_priv, orig_node);
                                 hlist_del_rcu(walk);
-                                call_rcu(&bucket->rcu, bucket_free_rcu);
-                                free_orig_node(orig_node, bat_priv);
+                                call_rcu(&bucket->rcu, bucket_free_orig_rcu);
                                 continue;
                         }