batman-adv: Protect global TQ window with a spinlock

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

net/batman-adv/originator.c

@@ -102,6 +102,7 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
 
 	INIT_HLIST_NODE(&neigh_node->list);
 	INIT_LIST_HEAD(&neigh_node->bonding_list);
+	spin_lock_init(&neigh_node->tq_lock);
 
 	memcpy(neigh_node->addr, neigh, ETH_ALEN);
 	neigh_node->orig_node = orig_neigh_node;

net/batman-adv/routing.c

@@ -415,10 +415,12 @@ static void update_orig(struct bat_priv *bat_priv,
 		if (is_duplicate)
 			continue;
 
+		spin_lock_bh(&tmp_neigh_node->tq_lock);
 		ring_buffer_set(tmp_neigh_node->tq_recv,
 				&tmp_neigh_node->tq_index, 0);
 		tmp_neigh_node->tq_avg =
 			ring_buffer_avg(tmp_neigh_node->tq_recv);
+		spin_unlock_bh(&tmp_neigh_node->tq_lock);
 	}
 
 	if (!neigh_node) {
@@ -443,10 +445,12 @@ static void update_orig(struct bat_priv *bat_priv,
 	orig_node->flags = batman_packet->flags;
 	neigh_node->last_valid = jiffies;
 
+	spin_lock_bh(&neigh_node->tq_lock);
 	ring_buffer_set(neigh_node->tq_recv,
 			&neigh_node->tq_index,
 			batman_packet->tq);
 	neigh_node->tq_avg = ring_buffer_avg(neigh_node->tq_recv);
+	spin_unlock_bh(&neigh_node->tq_lock);
 
 	if (!is_duplicate) {
 		orig_node->last_ttl = batman_packet->ttl;

net/batman-adv/types.h

@@ -125,6 +125,7 @@ struct neigh_node {
 	struct rcu_head rcu;
 	struct orig_node *orig_node;
 	struct hard_iface *if_incoming;
+	spinlock_t tq_lock;	/* protects: tq_recv, tq_index */
 };