[Bridge] [PATCH net-next 2/3] bridge: fdb: add proper lock checks in searching functions
Nikolay Aleksandrov
nikolay at cumulusnetworks.com
Mon Feb 13 13:59:10 UTC 2017
In order to avoid new errors add checks to br_fdb_find and fdb_find_rcu
functions. The first requires hash_lock, the second obviously RCU.
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
net/bridge/br_fdb.c | 4 ++++
net/bridge/br_private.h | 9 +++++++++
2 files changed, 13 insertions(+)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 04a53a0b733d..da5ed7d0a3c8 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -89,6 +89,8 @@ static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
{
struct net_bridge_fdb_entry *f;
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
hlist_for_each_entry_rcu(f, head, hlist)
if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)
break;
@@ -104,6 +106,8 @@ static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
struct net_bridge_fdb_entry *fdb;
+ WARN_ON_ONCE(!br_hash_lock_held(br));
+
rcu_read_lock();
fdb = fdb_find_rcu(head, addr, vid);
rcu_read_unlock();
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 61368186edea..2288fca7756c 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -531,6 +531,15 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
const unsigned char *addr, u16 vid);
+static inline bool br_hash_lock_held(struct net_bridge *br)
+{
+#ifdef CONFIG_LOCKDEP
+ return lockdep_is_held(&br->hash_lock);
+#else
+ return true;
+#endif
+}
+
/* br_forward.c */
enum br_pkt_type {
BR_PKT_UNICAST,
--
2.1.4
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