From c2ecba71717c4f60671175fd26083c35a4b9ad58 Mon Sep 17 00:00:00 2001 From: Pavel Emelianov Date: Tue, 17 Apr 2007 12:45:31 -0700 Subject: [PATCH] [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 --- include/linux/skbuff.h | 7 +++++++ net/core/neighbour.c | 5 ++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0e86b6007a0a..5992f65b4184 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -619,6 +619,13 @@ static inline void skb_queue_head_init(struct sk_buff_head *list) 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. * diff --git a/net/core/neighbour.c b/net/core/neighbour.c index cfc60019cf92..841e3f32cab1 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1331,6 +1331,8 @@ void neigh_parms_destroy(struct neigh_parms *parms) kfree(parms); } +static struct lock_class_key neigh_table_proxy_queue_class; + void neigh_table_init_no_netlink(struct neigh_table *tbl) { unsigned long now = jiffies; @@ -1379,7 +1381,8 @@ void neigh_table_init_no_netlink(struct neigh_table *tbl) init_timer(&tbl->proxy_timer); tbl->proxy_timer.data = (unsigned long)tbl; tbl->proxy_timer.function = neigh_proxy_process; - skb_queue_head_init(&tbl->proxy_queue); + skb_queue_head_init_class(&tbl->proxy_queue, + &neigh_table_proxy_queue_class); tbl->last_flush = now; tbl->last_rand = now + tbl->parms.reachable_time * 20; -- GitLab