WANG Cong 6bd00b8506 act_mirred: fix a race condition on mirred_list
After commit 1ce87720d456 ("net: sched: make cls_u32 lockless")
we began to release tc actions in a RCU callback. However,
mirred action relies on RTNL lock to protect the global
mirred_list, therefore we could have a race condition
between RCU callback and netdevice event, which caused
a list corruption as reported by Vinson.

Instead of relying on RTNL lock, introduce a spinlock to
protect this list.

Note, in non-bind case, it is still called with RTNL lock,
therefore should disable BH too.

Reported-by: Vinson Lee <vlee@twopensource.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 06:30:33 -07:00
..
2011-01-19 23:31:12 -08:00
2015-06-18 21:14:28 +02:00
2011-01-19 23:31:12 -08:00
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