[BRIDGE]: Properly dereference the br_should_route_hook

This hook is protected with the RCU, so simple

	if (br_should_route_hook)
		br_should_route_hook(...)

is not enough on some architectures.

Use the rcu_dereference/rcu_assign_pointer in this case.

Fixed Stephen's comment concerning using the typeof().

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 4 insertions, 3 deletions

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 3cedd4eeeed6..0ee79a726d91 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -122,6 +122,7 @@ static inline int is_link_local(const unsigned char *dest)
 struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
 {
         const unsigned char *dest = eth_hdr(skb)->h_dest;
+        int (*rhook)(struct sk_buff *skb);
 
         if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
                 goto drop;
@@ -147,9 +148,9 @@ struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
 
         switch (p->state) {
         case BR_STATE_FORWARDING:
-
-                if (br_should_route_hook) {
-                        if (br_should_route_hook(skb))
+                rhook = rcu_dereference(br_should_route_hook);
+                if (rhook != NULL) {
+                        if (rhook(skb))
                                 return skb;
                         dest = eth_hdr(skb)->h_dest;
                 }