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authorSven Eckelmann <sven@narfation.org>2016-01-05 12:06:25 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-01-31 11:29:02 -0800
commit11ed67672827aa98eaa0fe78510bb33eb3251407 (patch)
tree7c5981022756d51adbb25910994d44606a156b6e /net/batman-adv
parent568f95d027967fcfe287d9dddd3669eebbed96b3 (diff)
batman-adv: Drop immediate batadv_hard_iface free function
[ Upstream commit b4d922cfc9c08318eeb77d53b7633740e6b0efb0 ] It is not allowed to free the memory of an object which is part of a list which is protected by rcu-read-side-critical sections without making sure that no other context is accessing the object anymore. This usually happens by removing the references to this object and then waiting until the rcu grace period is over and no one (allowedly) accesses it anymore. But the _now functions ignore this completely. They free the object directly even when a different context still tries to access it. This has to be avoided and thus these functions must be removed and all functions have to use batadv_hardif_free_ref. Fixes: 89652331c00f ("batman-adv: split tq information in neigh_node struct") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <a@unstable.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/batman-adv')
-rw-r--r--net/batman-adv/hard-interface.h12
-rw-r--r--net/batman-adv/originator.c14
2 files changed, 7 insertions, 19 deletions
diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h
index 5a31420513e1..7b12ea8ea29d 100644
--- a/net/batman-adv/hard-interface.h
+++ b/net/batman-adv/hard-interface.h
@@ -75,18 +75,6 @@ batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface)
call_rcu(&hard_iface->rcu, batadv_hardif_free_rcu);
}
-/**
- * batadv_hardif_free_ref_now - decrement the hard interface refcounter and
- * possibly free it (without rcu callback)
- * @hard_iface: the hard interface to free
- */
-static inline void
-batadv_hardif_free_ref_now(struct batadv_hard_iface *hard_iface)
-{
- if (atomic_dec_and_test(&hard_iface->refcount))
- batadv_hardif_free_rcu(&hard_iface->rcu);
-}
-
static inline struct batadv_hard_iface *
batadv_primary_if_get_selected(struct batadv_priv *bat_priv)
{
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 0c27f07b5396..d9d2ceed69f2 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -189,16 +189,16 @@ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo)
/**
* batadv_neigh_node_free_rcu - free the neigh_node
- * @rcu: rcu pointer of the neigh_node
+ * batadv_neigh_node_release - release neigh_node from lists and queue for
+ * free after rcu grace period
+ * @neigh_node: neigh neighbor to free
*/
-static void batadv_neigh_node_free_rcu(struct rcu_head *rcu)
+static void batadv_neigh_node_release(struct batadv_neigh_node *neigh_node)
{
struct hlist_node *node_tmp;
- struct batadv_neigh_node *neigh_node;
struct batadv_neigh_ifinfo *neigh_ifinfo;
struct batadv_algo_ops *bao;
- neigh_node = container_of(rcu, struct batadv_neigh_node, rcu);
bao = neigh_node->orig_node->bat_priv->bat_algo_ops;
hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
@@ -209,9 +209,9 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu)
if (bao->bat_neigh_free)
bao->bat_neigh_free(neigh_node);
- batadv_hardif_free_ref_now(neigh_node->if_incoming);
+ batadv_hardif_free_ref(neigh_node->if_incoming);
- kfree(neigh_node);
+ kfree_rcu(neigh_node, rcu);
}
/**
@@ -222,7 +222,7 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu)
void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node)
{
if (atomic_dec_and_test(&neigh_node->refcount))
- call_rcu(&neigh_node->rcu, batadv_neigh_node_free_rcu);
+ batadv_neigh_node_release(neigh_node);
}
/**