3.16.82-rc1 review patch. If anyone has any objections, please let me know.
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From: Menglong Dong dong.menglong@zte.com.cn
commit 1d7ea55668878bb350979c377fc72509dd6f5b21 upstream.
While enqueueing a broadcast skb to port->bc_queue, schedule_work() is called to add port->bc_work, which processes the skbs in bc_queue, to "events" work queue. If port->bc_queue is full, the skb will be discarded and schedule_work(&port->bc_work) won't be called. However, if port->bc_queue is full and port->bc_work is not running or pending, port->bc_queue will keep full and schedule_work() won't be called any more, and all broadcast skbs to macvlan will be discarded. This case can happen:
macvlan_process_broadcast() is the pending function of port->bc_work, it moves all the skbs in port->bc_queue to the queue "list", and processes the skbs in "list". During this, new skbs will keep being added to port->bc_queue in macvlan_broadcast_enqueue(), and port->bc_queue may already full when macvlan_process_broadcast() return. This may happen, especially when there are a lot of real-time threads and the process is preempted.
Fix this by calling schedule_work(&port->bc_work) even if port->bc_work is full in macvlan_broadcast_enqueue().
Fixes: 412ca1550cbe ("macvlan: Move broadcasts into a work queue") Signed-off-by: Menglong Dong dong.menglong@zte.com.cn Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/net/macvlan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -262,10 +262,11 @@ static void macvlan_broadcast_enqueue(st } spin_unlock(&port->bc_queue.lock);
+ schedule_work(&port->bc_work); + if (err) goto free_nskb;
- schedule_work(&port->bc_work); return;
free_nskb: