[PATCH net-next 2/3] bridge: fdb: add proper lock checks in searching functions
From: Nikolay Aleksandrov <hidden>
Date: 2017-02-13 14:00:15
Also in:
bridge
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- 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