From 4945a58297bdc5e20dac7ac3364e6fe143f48866 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 16 Sep 2020 16:15:39 +0200 Subject: [PATCH 237/323] net: Dequeue in dev_cpu_dead() without the lock Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.215-rt107.tar.xz 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 --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 48fcb050b5a7b..7e8a78e1c749a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10988,7 +10988,7 @@ static int dev_cpu_dead(unsigned int oldcpu) 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); } -- 2.44.0