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authorMarek Lindner <lindner_marek@yahoo.de>2011-04-20 17:40:58 +0400
committerSven Eckelmann <sven@narfation.org>2011-05-02 00:49:03 +0400
commit32ae9b221e788413ce68feaae2ca39e406211a0a (patch)
treed827f989976a28fea5cdcb349c308baa98182c35 /net/batman-adv/hard-interface.h
parent71e4aa9c465fd66c110667ab5d620fb6a4ef2157 (diff)
downloadlinux-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.h18
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_ */