batman-adv: Move soft-interface initialization to ndo_init

The initialization of an net_device object should be done in the
init/constructor function and not from the outside after the register_netdevice
was done to avoid race conditions.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

2 files changed, 86 insertions, 88 deletions

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 368219e026a9..da000e90f87f 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -563,6 +563,11 @@ static int batadv_hard_if_event(struct notifier_block *this,
         struct batadv_hard_iface *primary_if = NULL;
         struct batadv_priv *bat_priv;
 
+        if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
+                batadv_sysfs_add_meshif(net_dev);
+                return NOTIFY_DONE;
+        }
+
         hard_iface = batadv_hardif_get_by_netdev(net_dev);
         if (!hard_iface && event == NETDEV_REGISTER)
                 hard_iface = batadv_hardif_add_interface(net_dev);
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index f93ae42abb58..c5cb0a7f8349 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -402,55 +402,6 @@ static void batadv_set_lockdep_class(struct net_device *dev)
 }
 
 /**
- * batadv_softif_init - Late stage initialization of soft interface
- * @dev: registered network device to modify
- *
- * Returns error code on failures
- */
-static int batadv_softif_init(struct net_device *dev)
-{
-        batadv_set_lockdep_class(dev);
-
-        return 0;
-}
-
-static const struct net_device_ops batadv_netdev_ops = {
-        .ndo_init = batadv_softif_init,
-        .ndo_open = batadv_interface_open,
-        .ndo_stop = batadv_interface_release,
-        .ndo_get_stats = batadv_interface_stats,
-        .ndo_set_mac_address = batadv_interface_set_mac_addr,
-        .ndo_change_mtu = batadv_interface_change_mtu,
-        .ndo_start_xmit = batadv_interface_tx,
-        .ndo_validate_addr = eth_validate_addr
-};
-
-static void batadv_interface_setup(struct net_device *dev)
-{
-        struct batadv_priv *priv = netdev_priv(dev);
-
-        ether_setup(dev);
-
-        dev->netdev_ops = &batadv_netdev_ops;
-        dev->destructor = free_netdev;
-        dev->tx_queue_len = 0;
-
-        /* can't call min_mtu, because the needed variables
-         * have not been initialized yet
-         */
-        dev->mtu = ETH_DATA_LEN;
-        /* reserve more space in the skbuff for our header */
-        dev->hard_header_len = BATADV_HEADER_LEN;
-
-        /* generate random address */
-        eth_hw_addr_random(dev);
-
-        SET_ETHTOOL_OPS(dev, &batadv_ethtool_ops);
-
-        memset(priv, 0, sizeof(*priv));
-}
-
-/**
  * batadv_softif_destroy_finish - cleans up the remains of a softif
  * @work: work queue item
  *
@@ -474,21 +425,22 @@ static void batadv_softif_destroy_finish(struct work_struct *work)
         rtnl_unlock();
 }
 
-struct net_device *batadv_softif_create(const char *name)
+/**
+ * batadv_softif_init_late - late stage initialization of soft interface
+ * @dev: registered network device to modify
+ *
+ * Returns error code on failures
+ */
+static int batadv_softif_init_late(struct net_device *dev)
 {
-        struct net_device *soft_iface;
         struct batadv_priv *bat_priv;
         int ret;
         size_t cnt_len = sizeof(uint64_t) * BATADV_CNT_NUM;
 
-        soft_iface = alloc_netdev(sizeof(*bat_priv), name,
-                                  batadv_interface_setup);
-
-        if (!soft_iface)
-                goto out;
+        batadv_set_lockdep_class(dev);
 
-        bat_priv = netdev_priv(soft_iface);
-        bat_priv->soft_iface = soft_iface;
+        bat_priv = netdev_priv(dev);
+        bat_priv->soft_iface = dev;
         INIT_WORK(&bat_priv->cleanup_work, batadv_softif_destroy_finish);
 
         /* batadv_interface_stats() needs to be available as soon as
@@ -496,14 +448,7 @@ struct net_device *batadv_softif_create(const char *name)
          */
         bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(uint64_t));
         if (!bat_priv->bat_counters)
-                goto free_soft_iface;
-
-        ret = register_netdevice(soft_iface);
-        if (ret < 0) {
-                pr_err("Unable to register the batman interface '%s': %i\n",
-                       name, ret);
-                goto free_bat_counters;
-        }
+                return -ENOMEM;
 
         atomic_set(&bat_priv->aggregated_ogms, 1);
         atomic_set(&bat_priv->bonding, 0);
@@ -541,41 +486,89 @@ struct net_device *batadv_softif_create(const char *name)
         bat_priv->primary_if = NULL;
         bat_priv->num_ifaces = 0;
 
-        ret = batadv_algo_select(bat_priv, batadv_routing_algo);
-        if (ret < 0)
-                goto unreg_soft_iface;
-
         batadv_nc_init_bat_priv(bat_priv);
 
-        ret = batadv_sysfs_add_meshif(soft_iface);
+        ret = batadv_algo_select(bat_priv, batadv_routing_algo);
         if (ret < 0)
-                goto unreg_soft_iface;
+                goto free_bat_counters;
 
-        ret = batadv_debugfs_add_meshif(soft_iface);
+        ret = batadv_debugfs_add_meshif(dev);
         if (ret < 0)
-                goto unreg_sysfs;
+                goto free_bat_counters;
 
-        ret = batadv_mesh_init(soft_iface);
+        ret = batadv_mesh_init(dev);
         if (ret < 0)
                 goto unreg_debugfs;
 
-        return soft_iface;
+        return 0;
 
 unreg_debugfs:
-        batadv_debugfs_del_meshif(soft_iface);
-unreg_sysfs:
-        batadv_sysfs_del_meshif(soft_iface);
-unreg_soft_iface:
-        free_percpu(bat_priv->bat_counters);
-        unregister_netdevice(soft_iface);
-        return NULL;
-
+        batadv_debugfs_del_meshif(dev);
 free_bat_counters:
         free_percpu(bat_priv->bat_counters);
-free_soft_iface:
-        free_netdev(soft_iface);
-out:
-        return NULL;
+
+        return ret;
+}
+
+static const struct net_device_ops batadv_netdev_ops = {
+        .ndo_init = batadv_softif_init_late,
+        .ndo_open = batadv_interface_open,
+        .ndo_stop = batadv_interface_release,
+        .ndo_get_stats = batadv_interface_stats,
+        .ndo_set_mac_address = batadv_interface_set_mac_addr,
+        .ndo_change_mtu = batadv_interface_change_mtu,
+        .ndo_start_xmit = batadv_interface_tx,
+        .ndo_validate_addr = eth_validate_addr
+};
+
+/**
+ * batadv_softif_init_early - early stage initialization of soft interface
+ * @dev: registered network device to modify
+ */
+static void batadv_softif_init_early(struct net_device *dev)
+{
+        struct batadv_priv *priv = netdev_priv(dev);
+
+        ether_setup(dev);
+
+        dev->netdev_ops = &batadv_netdev_ops;
+        dev->destructor = free_netdev;
+        dev->tx_queue_len = 0;
+
+        /* can't call min_mtu, because the needed variables
+         * have not been initialized yet
+         */
+        dev->mtu = ETH_DATA_LEN;
+        /* reserve more space in the skbuff for our header */
+        dev->hard_header_len = BATADV_HEADER_LEN;
+
+        /* generate random address */
+        eth_hw_addr_random(dev);
+
+        SET_ETHTOOL_OPS(dev, &batadv_ethtool_ops);
+
+        memset(priv, 0, sizeof(*priv));
+}
+
+struct net_device *batadv_softif_create(const char *name)
+{
+        struct net_device *soft_iface;
+        int ret;
+
+        soft_iface = alloc_netdev(sizeof(struct batadv_priv), name,
+                                  batadv_softif_init_early);
+        if (!soft_iface)
+                return NULL;
+
+        ret = register_netdevice(soft_iface);
+        if (ret < 0) {
+                pr_err("Unable to register the batman interface '%s': %i\n",
+                       name, ret);
+                free_netdev(soft_iface);
+                return NULL;
+        }
+
+        return soft_iface;
 }
 
 void batadv_softif_destroy(struct net_device *soft_iface)