batman-adv: Use rcu_dereference_protected by update-side

Usually rcu_dereference isn't necessary in situations were the
RCU-protected data structure cannot change, but sparse and lockdep still
need a similar functionality for analysis. rcu_dereference_protected
implements the reduced version which should be used to support the
dynamic and static analysis.

Signed-off-by: Sven Eckelmann <sven@narfation.org>

3 files changed, 4 insertions, 3 deletions

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index a44dff3efb7f..ab597c4f9ddd 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -86,7 +86,7 @@ static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
         if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
                 new_gw_node = NULL;
 
-        curr_gw_node = bat_priv->curr_gw;
+        curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1);
         rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
 
         if (curr_gw_node)
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index e0052cf389db..a3fbfb5c92f1 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -138,7 +138,7 @@ static void primary_if_select(struct bat_priv *bat_priv,
         if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
                 new_hard_iface = NULL;
 
-        curr_hard_iface = bat_priv->primary_if;
+        curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 
         if (curr_hard_iface)
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index cead606008a1..b8d3f248efdc 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -241,7 +241,8 @@ static void softif_neigh_vid_select(struct bat_priv *bat_priv,
         if (new_neigh && !atomic_inc_not_zero(&new_neigh->refcount))
                 new_neigh = NULL;
 
-        curr_neigh = softif_neigh_vid->softif_neigh;
+        curr_neigh = rcu_dereference_protected(softif_neigh_vid->softif_neigh,
+                                               1);
         rcu_assign_pointer(softif_neigh_vid->softif_neigh, new_neigh);
 
         if ((curr_neigh) && (!new_neigh))