Commit deed9660 authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Antonio Quartulli

batman-adv: Drop immediate batadv_orig_ifinfo free function

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_orig_ifinfo_free_ref.

Fixes: 7351a482 ("batman-adv: split out router from orig_node")
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarAntonio Quartulli <a@unstable.cc>
parent 44e8e7e9
...@@ -754,76 +754,79 @@ static void batadv_orig_ifinfo_free_rcu(struct rcu_head *rcu) ...@@ -754,76 +754,79 @@ static void batadv_orig_ifinfo_free_rcu(struct rcu_head *rcu)
} }
/** /**
* batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly release
* the orig_ifinfo (without rcu callback) * the orig_ifinfo
* @orig_ifinfo: the orig_ifinfo object to release * @orig_ifinfo: the orig_ifinfo object to release
*/ */
static void void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo)
batadv_orig_ifinfo_free_ref_now(struct batadv_orig_ifinfo *orig_ifinfo)
{ {
if (atomic_dec_and_test(&orig_ifinfo->refcount)) if (atomic_dec_and_test(&orig_ifinfo->refcount))
batadv_orig_ifinfo_free_rcu(&orig_ifinfo->rcu); call_rcu(&orig_ifinfo->rcu, batadv_orig_ifinfo_free_rcu);
} }
/** /**
* batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free * batadv_orig_node_free_rcu - free the orig_node
* the orig_ifinfo * @rcu: rcu pointer of the orig_node
* @orig_ifinfo: the orig_ifinfo object to release
*/ */
void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo) static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
{ {
if (atomic_dec_and_test(&orig_ifinfo->refcount)) struct batadv_orig_node *orig_node;
call_rcu(&orig_ifinfo->rcu, batadv_orig_ifinfo_free_rcu);
orig_node = container_of(rcu, struct batadv_orig_node, rcu);
batadv_mcast_purge_orig(orig_node);
batadv_frag_purge_orig(orig_node, NULL);
if (orig_node->bat_priv->bat_algo_ops->bat_orig_free)
orig_node->bat_priv->bat_algo_ops->bat_orig_free(orig_node);
kfree(orig_node->tt_buff);
kfree(orig_node);
} }
static void batadv_orig_node_free_rcu(struct rcu_head *rcu) /**
* batadv_orig_node_release - release orig_node from lists and queue for
* free after rcu grace period
* @orig_node: the orig node to free
*/
static void batadv_orig_node_release(struct batadv_orig_node *orig_node)
{ {
struct hlist_node *node_tmp; struct hlist_node *node_tmp;
struct batadv_neigh_node *neigh_node; struct batadv_neigh_node *neigh_node;
struct batadv_orig_node *orig_node;
struct batadv_orig_ifinfo *orig_ifinfo; struct batadv_orig_ifinfo *orig_ifinfo;
orig_node = container_of(rcu, struct batadv_orig_node, rcu);
spin_lock_bh(&orig_node->neigh_list_lock); spin_lock_bh(&orig_node->neigh_list_lock);
/* for all neighbors towards this originator ... */ /* for all neighbors towards this originator ... */
hlist_for_each_entry_safe(neigh_node, node_tmp, hlist_for_each_entry_safe(neigh_node, node_tmp,
&orig_node->neigh_list, list) { &orig_node->neigh_list, list) {
hlist_del_rcu(&neigh_node->list); hlist_del_rcu(&neigh_node->list);
batadv_neigh_node_free_ref_now(neigh_node); batadv_neigh_node_free_ref(neigh_node);
} }
hlist_for_each_entry_safe(orig_ifinfo, node_tmp, hlist_for_each_entry_safe(orig_ifinfo, node_tmp,
&orig_node->ifinfo_list, list) { &orig_node->ifinfo_list, list) {
hlist_del_rcu(&orig_ifinfo->list); hlist_del_rcu(&orig_ifinfo->list);
batadv_orig_ifinfo_free_ref_now(orig_ifinfo); batadv_orig_ifinfo_free_ref(orig_ifinfo);
} }
spin_unlock_bh(&orig_node->neigh_list_lock); spin_unlock_bh(&orig_node->neigh_list_lock);
batadv_mcast_purge_orig(orig_node);
/* Free nc_nodes */ /* Free nc_nodes */
batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL); batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL);
batadv_frag_purge_orig(orig_node, NULL); call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu);
if (orig_node->bat_priv->bat_algo_ops->bat_orig_free)
orig_node->bat_priv->bat_algo_ops->bat_orig_free(orig_node);
kfree(orig_node->tt_buff);
kfree(orig_node);
} }
/** /**
* batadv_orig_node_free_ref - decrement the orig node refcounter and possibly * batadv_orig_node_free_ref - decrement the orig node refcounter and possibly
* schedule an rcu callback for freeing it * release it
* @orig_node: the orig node to free * @orig_node: the orig node to free
*/ */
void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node) void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node)
{ {
if (atomic_dec_and_test(&orig_node->refcount)) if (atomic_dec_and_test(&orig_node->refcount))
call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu); batadv_orig_node_release(orig_node);
} }
/** /**
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment