[PATCH 4.4 90/96] netfilter: nft_queue: use raw_smp_processor_id()

Greg Kroah-Hartman
2017-11-28T10:32:21Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit c2e756ff9e699865d294cdc112acfc36419cf5cc ]

Using smp_processor_id() causes splats with PREEMPT_RCU:

[19379.552780] BUG: using smp_processor_id() in preemptible [00000000] code: ping/32389
[19379.552793] caller is debug_smp_processor_id+0x17/0x19
[...]
[19379.552823] Call Trace:
[19379.552832] [<ffffffff81274e9e>] dump_stack+0x67/0x90
[19379.552837] [<ffffffff8129a4d4>] check_preemption_disabled+0xe5/0xf5
[19379.552842] [<ffffffff8129a4fb>] debug_smp_processor_id+0x17/0x19
[19379.552849] [<ffffffffa07c42dd>] nft_queue_eval+0x35/0x20c [nft_queue]

No need to disable preemption since we only fetch the numeric value, so
let's use raw_smp_processor_id() instead.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netfilter/nft_queue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/netfilter/nft_queue.c
+++ b/net/netfilter/nft_queue.c
@@ -37,7 +37,7 @@ static void nft_queue_eval(const struct

if (priv->queues_total > 1) {
if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT) {
- int cpu = smp_processor_id();
+ int cpu = raw_smp_processor_id();

queue = priv->queuenum + cpu % priv->queues_total;
} else {