4f2c6ae5c6
When switchdev drivers process FDB notifications from the underlying
device they resolve the netdev to which the entry points to and notify
the bridge using the switchdev notifier.
However, since the RTNL mutex is not held there is nothing preventing
the netdev from disappearing in the middle, which will cause
br_switchdev_event() to dereference a non-existing netdev.
Make switchdev drivers hold the lock at the beginning of the
notification processing session and release it once it ends, after
notifying the bridge.
Also, remove switchdev_mutex and fdb_lock, as they are no longer needed
when RTNL mutex is held.
Fixes: 03bf0c2812
("switchdev: introduce switchdev notifier")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
274 lines
5.8 KiB
C
274 lines
5.8 KiB
C
/*
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* Generic parts
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* Linux ethernet bridge
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*
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* Authors:
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* Lennert Buytenhek <buytenh@gnu.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/init.h>
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#include <linux/llc.h>
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#include <net/llc.h>
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#include <net/stp.h>
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#include <net/switchdev.h>
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#include "br_private.h"
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/*
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* Handle changes in state of network devices enslaved to a bridge.
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*
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* Note: don't care about up/down if bridge itself is down, because
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* port state is checked when bridge is brought up.
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*/
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static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
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{
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struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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struct net_bridge_port *p;
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struct net_bridge *br;
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bool changed_addr;
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int err;
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/* register of bridge completed, add sysfs entries */
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if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
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br_sysfs_addbr(dev);
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return NOTIFY_DONE;
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}
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/* not a port of a bridge */
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p = br_port_get_rtnl(dev);
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if (!p)
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return NOTIFY_DONE;
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br = p->br;
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switch (event) {
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case NETDEV_CHANGEMTU:
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dev_set_mtu(br->dev, br_min_mtu(br));
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break;
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case NETDEV_CHANGEADDR:
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spin_lock_bh(&br->lock);
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br_fdb_changeaddr(p, dev->dev_addr);
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changed_addr = br_stp_recalculate_bridge_id(br);
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spin_unlock_bh(&br->lock);
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if (changed_addr)
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call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
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break;
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case NETDEV_CHANGE:
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br_port_carrier_check(p);
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break;
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case NETDEV_FEAT_CHANGE:
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netdev_update_features(br->dev);
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break;
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case NETDEV_DOWN:
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spin_lock_bh(&br->lock);
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if (br->dev->flags & IFF_UP)
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br_stp_disable_port(p);
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spin_unlock_bh(&br->lock);
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break;
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case NETDEV_UP:
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if (netif_running(br->dev) && netif_oper_up(dev)) {
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spin_lock_bh(&br->lock);
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br_stp_enable_port(p);
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spin_unlock_bh(&br->lock);
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}
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break;
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case NETDEV_UNREGISTER:
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br_del_if(br, dev);
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break;
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case NETDEV_CHANGENAME:
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err = br_sysfs_renameif(p);
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if (err)
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return notifier_from_errno(err);
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break;
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case NETDEV_PRE_TYPE_CHANGE:
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/* Forbid underlaying device to change its type. */
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return NOTIFY_BAD;
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case NETDEV_RESEND_IGMP:
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/* Propagate to master device */
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call_netdevice_notifiers(event, br->dev);
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break;
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}
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/* Events that may cause spanning tree to refresh */
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if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
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event == NETDEV_CHANGE || event == NETDEV_DOWN)
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br_ifinfo_notify(RTM_NEWLINK, p);
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return NOTIFY_DONE;
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}
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static struct notifier_block br_device_notifier = {
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.notifier_call = br_device_event
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};
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/* called with RTNL */
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static int br_switchdev_event(struct notifier_block *unused,
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unsigned long event, void *ptr)
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{
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struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
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struct net_bridge_port *p;
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struct net_bridge *br;
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struct switchdev_notifier_fdb_info *fdb_info;
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int err = NOTIFY_DONE;
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p = br_port_get_rtnl(dev);
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if (!p)
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goto out;
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br = p->br;
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switch (event) {
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case SWITCHDEV_FDB_ADD:
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fdb_info = ptr;
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err = br_fdb_external_learn_add(br, p, fdb_info->addr,
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fdb_info->vid);
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if (err)
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err = notifier_from_errno(err);
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break;
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case SWITCHDEV_FDB_DEL:
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fdb_info = ptr;
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err = br_fdb_external_learn_del(br, p, fdb_info->addr,
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fdb_info->vid);
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if (err)
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err = notifier_from_errno(err);
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break;
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}
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out:
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return err;
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}
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static struct notifier_block br_switchdev_notifier = {
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.notifier_call = br_switchdev_event,
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};
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static void __net_exit br_net_exit(struct net *net)
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{
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struct net_device *dev;
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LIST_HEAD(list);
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rtnl_lock();
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for_each_netdev(net, dev)
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if (dev->priv_flags & IFF_EBRIDGE)
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br_dev_delete(dev, &list);
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unregister_netdevice_many(&list);
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rtnl_unlock();
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}
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static struct pernet_operations br_net_ops = {
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.exit = br_net_exit,
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};
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static const struct stp_proto br_stp_proto = {
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.rcv = br_stp_rcv,
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};
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static int __init br_init(void)
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{
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int err;
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BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
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err = stp_proto_register(&br_stp_proto);
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if (err < 0) {
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pr_err("bridge: can't register sap for STP\n");
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return err;
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}
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err = br_fdb_init();
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if (err)
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goto err_out;
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err = register_pernet_subsys(&br_net_ops);
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if (err)
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goto err_out1;
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err = br_nf_core_init();
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if (err)
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goto err_out2;
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err = register_netdevice_notifier(&br_device_notifier);
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if (err)
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goto err_out3;
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err = register_switchdev_notifier(&br_switchdev_notifier);
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if (err)
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goto err_out4;
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err = br_netlink_init();
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if (err)
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goto err_out5;
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brioctl_set(br_ioctl_deviceless_stub);
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#if IS_ENABLED(CONFIG_ATM_LANE)
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br_fdb_test_addr_hook = br_fdb_test_addr;
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#endif
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pr_info("bridge: automatic filtering via arp/ip/ip6tables has been "
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"deprecated. Update your scripts to load br_netfilter if you "
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"need this.\n");
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return 0;
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err_out5:
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unregister_switchdev_notifier(&br_switchdev_notifier);
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err_out4:
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unregister_netdevice_notifier(&br_device_notifier);
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err_out3:
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br_nf_core_fini();
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err_out2:
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unregister_pernet_subsys(&br_net_ops);
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err_out1:
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br_fdb_fini();
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err_out:
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stp_proto_unregister(&br_stp_proto);
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return err;
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}
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static void __exit br_deinit(void)
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{
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stp_proto_unregister(&br_stp_proto);
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br_netlink_fini();
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unregister_switchdev_notifier(&br_switchdev_notifier);
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unregister_netdevice_notifier(&br_device_notifier);
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brioctl_set(NULL);
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unregister_pernet_subsys(&br_net_ops);
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rcu_barrier(); /* Wait for completion of call_rcu()'s */
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br_nf_core_fini();
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#if IS_ENABLED(CONFIG_ATM_LANE)
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br_fdb_test_addr_hook = NULL;
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#endif
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br_fdb_fini();
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}
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module_init(br_init)
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module_exit(br_deinit)
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MODULE_LICENSE("GPL");
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MODULE_VERSION(BR_VERSION);
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MODULE_ALIAS_RTNL_LINK("bridge");
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