[B.A.T.M.A.N.] [PATCH maint] batman-adv: Modify neigh_list only with rcu-list functions

[Sven Eckelmann]

The batadv_hard_iface::neigh_list is accessed via rcu based primitives.
Thus all operations done on it have to fulfill the requirements by RCU. So
using non-RCU mechanisms like hlist_add_head is not allowed because it
misses the barriers required to protect concurrent readers when accessing
the data behind the pointer.

Fixes: fed2826b490c ("batman-adv: add list of unique single hop neighbors per 
hard-interface")
Signed-off-by: Sven Eckelmann <sven.eckelm...@open-mesh.com>
---
 net/batman-adv/originator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 3940b5d..3e9667e 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -537,7 +537,7 @@ batadv_hardif_neigh_create(struct batadv_hard_iface 
*hard_iface,
        if (bat_priv->algo_ops->neigh.hardif_init)
                bat_priv->algo_ops->neigh.hardif_init(hardif_neigh);
 
-       hlist_add_head(&hardif_neigh->list, &hard_iface->neigh_list);
+       hlist_add_head_rcu(&hardif_neigh->list, &hard_iface->neigh_list);
 
 out:
        spin_unlock_bh(&hard_iface->neigh_list_lock);
-- 
2.9.3