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| author | Eric Dumazet <edumazet@google.com> | 2012-08-22 21:50:59 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-08-23 09:24:42 -0700 |
| commit | 748e2d9396a18c3fd3d07d47c1b41320acf1fbf4 (patch) | |
| tree | 49bde8c370615258baada1d43acda2b3fb3625c2 /net/core/dev.c | |
| parent | 0fa7fa98dbcc2789409ed24e885485e645803d7f (diff) | |
| download | lwn-748e2d9396a18c3fd3d07d47c1b41320acf1fbf4.tar.gz lwn-748e2d9396a18c3fd3d07d47c1b41320acf1fbf4.zip | |
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.c | 9 |
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", |