[NET]: Set a separate lockdep class for neighbour table's proxy_queue
Otherwise the following calltrace will lead to a wrong
lockdep warning:
neigh_proxy_process()
`- lock(neigh_table->proxy_queue.lock);
arp_redo /* via tbl->proxy_redo */
arp_process
neigh_event_ns
neigh_update
skb_queue_purge
`- lock(neighbor->arp_queue.lock);
This is not a deadlock actually, as neighbor table's proxy_queue
and the neighbor's arp_queue are different queues.
Lockdep thinks there is a deadlock as both queues are initialized
with skb_queue_head_init() and thus have a common class.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 0e86b60..5992f65 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -619,6 +619,13 @@
list->qlen = 0;
}
+static inline void skb_queue_head_init_class(struct sk_buff_head *list,
+ struct lock_class_key *class)
+{
+ skb_queue_head_init(list);
+ lockdep_set_class(&list->lock, class);
+}
+
/*
* Insert an sk_buff at the start of a list.
*