From 9873cd435afb128336fc45afda43e9fc497314a7 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 16 Sep 2020 16:15:39 +0200 Subject: [PATCH 107/158] net: Dequeue in dev_cpu_dead() without the lock Upstream uses skb_dequeue() to acquire lock of `input_pkt_queue'. The reason is to synchronize against a remote CPU which still thinks that the CPU is online enqueues packets to this CPU. There are no guarantees that the packet is enqueued before the callback is run, it just hope. RT however complains about an not initialized lock because it uses another lock for `input_pkt_queue' due to the IRQ-off nature of the context. Use the unlocked dequeue version for `input_pkt_queue'. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-5.15.19-rt29/net/core/dev.c =================================================================== --- linux-5.15.19-rt29.orig/net/core/dev.c +++ linux-5.15.19-rt29/net/core/dev.c @@ -11328,7 +11328,7 @@ static int dev_cpu_dead(unsigned int old netif_rx_ni(skb); input_queue_head_incr(oldsd); } - while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) { + while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) { netif_rx_ni(skb); input_queue_head_incr(oldsd); }