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authorEric Dumazet <edumazet@google.com>2012-08-22 21:50:59 +0000
committerDavid S. Miller <davem@davemloft.net>2012-08-23 09:24:42 -0700
commit748e2d9396a18c3fd3d07d47c1b41320acf1fbf4 (patch)
tree49bde8c370615258baada1d43acda2b3fb3625c2 /net/core/dev.c
parent0fa7fa98dbcc2789409ed24e885485e645803d7f (diff)
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net: reinstate rtnl in call_netdevice_notifiers()
Eric Biederman pointed out that not holding RTNL while calling call_netdevice_notifiers() was racy. This patch is a direct transcription his feedback against commit 0115e8e30d6fc (net: remove delay at device dismantle) Thanks Eric ! Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Gao feng <gaofeng@cn.fujitsu.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
-rw-r--r--net/core/dev.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 0640d2a859c6..bc857fead8c8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1466,8 +1466,7 @@ EXPORT_SYMBOL(unregister_netdevice_notifier);
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
{
- if (val != NETDEV_UNREGISTER_FINAL)
- ASSERT_RTNL();
+ ASSERT_RTNL();
return raw_notifier_call_chain(&netdev_chain, val, dev);
}
EXPORT_SYMBOL(call_netdevice_notifiers);
@@ -5782,7 +5781,11 @@ static void netdev_wait_allrefs(struct net_device *dev)
/* Rebroadcast unregister notification */
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
+
+ __rtnl_unlock();
rcu_barrier();
+ rtnl_lock();
+
call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
&dev->state)) {
@@ -5855,7 +5858,9 @@ void netdev_run_todo(void)
= list_first_entry(&list, struct net_device, todo_list);
list_del(&dev->todo_list);
+ rtnl_lock();
call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
+ __rtnl_unlock();
if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
pr_err("network todo '%s' but state %d\n",