diff options
| author | Marek Lindner <lindner_marek@yahoo.de> | 2011-04-20 17:40:58 +0400 |
|---|---|---|
| committer | Sven Eckelmann <sven@narfation.org> | 2011-05-02 00:49:03 +0400 |
| commit | 32ae9b221e788413ce68feaae2ca39e406211a0a (patch) | |
| tree | d827f989976a28fea5cdcb349c308baa98182c35 /net/batman-adv/hard-interface.h | |
| parent | 71e4aa9c465fd66c110667ab5d620fb6a4ef2157 (diff) | |
| download | linux-32ae9b221e788413ce68feaae2ca39e406211a0a.tar.xz | |
batman-adv: Make bat_priv->primary_if an rcu protected pointer
The rcu protected macros rcu_dereference() and rcu_assign_pointer()
for the bat_priv->primary_if need to be used, as well as spin/rcu locking.
Otherwise we might end up using a primary_if pointer pointing to already
freed memory.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Diffstat (limited to 'net/batman-adv/hard-interface.h')
| -rw-r--r-- | net/batman-adv/hard-interface.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h index a9ddf36e51c8..64265991460b 100644 --- a/net/batman-adv/hard-interface.h +++ b/net/batman-adv/hard-interface.h @@ -45,4 +45,22 @@ static inline void hardif_free_ref(struct hard_iface *hard_iface) call_rcu(&hard_iface->rcu, hardif_free_rcu); } +static inline struct hard_iface *primary_if_get_selected( + struct bat_priv *bat_priv) +{ + struct hard_iface *hard_iface; + + rcu_read_lock(); + hard_iface = rcu_dereference(bat_priv->primary_if); + if (!hard_iface) + goto out; + + if (!atomic_inc_not_zero(&hard_iface->refcount)) + hard_iface = NULL; + +out: + rcu_read_unlock(); + return hard_iface; +} + #endif /* _NET_BATMAN_ADV_HARD_INTERFACE_H_ */ |