batman-adv: Use kref_get for hard_iface subfunctions

The callers of the functions using batadv_hard_iface objects already make
sure that they hold a valid reference. The subfunctions don't have
to check whether the reference counter is > 0 because this was checked by
the callers.

The kref_get function instead WARNs (with debug information) when the
reference counter would still be 0. This makes a bug in batman-adv better
visible because kref_get_unless_zero would have ignored this problem.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 57e9962c7090a7925a6d373c5edfb4b6a7ee8d96..eb3435de54b5b6c6ec58c7be2d94a53f26d25eba 100644 (file)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -681,18 +681,12 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        unsigned char *skb_buff;
        unsigned int skb_size;
 
-       if (!kref_get_unless_zero(&if_incoming->refcount))
-               return;
-
-       if (!kref_get_unless_zero(&if_outgoing->refcount))
-               goto out_free_incoming;
-
        /* own packet should always be scheduled */
        if (!own_packet) {
                if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {
                        batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
                                   "batman packet queue full\n");
-                       goto out_free_outgoing;
+                       return;
                }
        }
 
@@ -718,6 +712,8 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        forw_packet_aggr->packet_len = packet_len;
        memcpy(skb_buff, packet_buff, packet_len);
 
+       kref_get(&if_incoming->refcount);
+       kref_get(&if_outgoing->refcount);
        forw_packet_aggr->own = own_packet;
        forw_packet_aggr->if_incoming = if_incoming;
        forw_packet_aggr->if_outgoing = if_outgoing;
@@ -747,10 +743,6 @@ out_free_forw_packet:
 out_nomem:
        if (!own_packet)
                atomic_inc(&bat_priv->batman_queue_left);
-out_free_outgoing:
-       batadv_hardif_put(if_outgoing);
-out_free_incoming:
-       batadv_hardif_put(if_incoming);
 }
 
 /* aggregate a new packet into the existing ogm packet */

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index d3d37f3f99cf4f27afe13eeaffc8044d8c3df036..7c1d8d7ac548aa39ade1395fcba7b26ffcb898e9 100644 (file)
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -236,8 +236,8 @@ static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 
        ASSERT_RTNL();
 
-       if (new_hard_iface && !kref_get_unless_zero(&new_hard_iface->refcount))
-               new_hard_iface = NULL;
+       if (new_hard_iface)
+               kref_get(&new_hard_iface->refcount);
 
        curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
        rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
@@ -467,8 +467,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
        if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
                goto out;
 
-       if (!kref_get_unless_zero(&hard_iface->refcount))
-               goto out;
+       kref_get(&hard_iface->refcount);
 
        soft_iface = dev_get_by_name(net, iface_name);
 

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 2ed2cc89a669fc5afbeace39a807d7571618f077..04fa139911c36670e3f0fc4c46cb9b94439a0f42 100644 (file)
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -374,12 +374,8 @@ batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node,
        if (!orig_ifinfo)
                goto out;
 
-       if (if_outgoing != BATADV_IF_DEFAULT &&
-           !kref_get_unless_zero(&if_outgoing->refcount)) {
-               kfree(orig_ifinfo);
-               orig_ifinfo = NULL;
-               goto out;
-       }
+       if (if_outgoing != BATADV_IF_DEFAULT)
+               kref_get(&if_outgoing->refcount);
 
        reset_time = jiffies - 1;
        reset_time -= msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
@@ -455,11 +451,8 @@ batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh,
        if (!neigh_ifinfo)
                goto out;
 
-       if (if_outgoing && !kref_get_unless_zero(&if_outgoing->refcount)) {
-               kfree(neigh_ifinfo);
-               neigh_ifinfo = NULL;
-               goto out;
-       }
+       if (if_outgoing)
+               kref_get(&if_outgoing->refcount);
 
        INIT_HLIST_NODE(&neigh_ifinfo->list);
        kref_init(&neigh_ifinfo->refcount);
@@ -532,15 +525,11 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface,
        if (hardif_neigh)
                goto out;
 
-       if (!kref_get_unless_zero(&hard_iface->refcount))
-               goto out;
-
        hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC);
-       if (!hardif_neigh) {
-               batadv_hardif_put(hard_iface);
+       if (!hardif_neigh)
                goto out;
-       }
 
+       kref_get(&hard_iface->refcount);
        INIT_HLIST_NODE(&hardif_neigh->list);
        ether_addr_copy(hardif_neigh->addr, neigh_addr);
        hardif_neigh->if_incoming = hard_iface;
@@ -643,16 +632,11 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node,
        if (!neigh_node)
                goto out;
 
-       if (!kref_get_unless_zero(&hard_iface->refcount)) {
-               kfree(neigh_node);
-               neigh_node = NULL;
-               goto out;
-       }
-
        INIT_HLIST_NODE(&neigh_node->list);
        INIT_HLIST_HEAD(&neigh_node->ifinfo_list);
        spin_lock_init(&neigh_node->ifinfo_lock);
 
+       kref_get(&hard_iface->refcount);
        ether_addr_copy(neigh_node->addr, neigh_addr);
        neigh_node->if_incoming = hard_iface;
        neigh_node->orig_node = orig_node;