summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSven Eckelmann <sven@narfation.org>2016-01-05 12:06:25 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-01-31 11:23:37 -0800
commitae3eb44e0e8b4e0fe4ab51e0a91d76517abc1e30 (patch)
treebb233843c000e168bf69823d539ee3afddc3ca1c
parent924224c6e44a393a2a41385d699230384ea23df5 (diff)
downloadlwn-ae3eb44e0e8b4e0fe4ab51e0a91d76517abc1e30.tar.gz
lwn-ae3eb44e0e8b4e0fe4ab51e0a91d76517abc1e30.zip
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>
-rw-r--r--net/batman-adv/hard-interface.h12
-rw-r--r--net/batman-adv/originator.c16
2 files changed, 7 insertions, 21 deletions
diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h
index 1918cd50b62e..b6bff9c1877a 100644
--- a/net/batman-adv/hard-interface.h
+++ b/net/batman-adv/hard-interface.h
@@ -64,18 +64,6 @@ 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 23db96f0ee2a..36dfa3bac2b7 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -175,24 +175,22 @@ 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;
- neigh_node = container_of(rcu, struct batadv_neigh_node, rcu);
-
hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
&neigh_node->ifinfo_list, list) {
batadv_neigh_ifinfo_free_ref(neigh_ifinfo);
}
- 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);
}
/**
@@ -203,7 +201,7 @@ 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);
}
/**