netfilter: nft_queue: use raw_smp_processor_id()
authorPablo Neira Ayuso <pablo@netfilter.org>
Sun, 11 Dec 2016 19:46:51 +0000 (20:46 +0100)
committerPablo Neira Ayuso <pablo@netfilter.org>
Wed, 14 Dec 2016 22:39:01 +0000 (23:39 +0100)
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>
net/netfilter/nft_queue.c

index 3e19fa1..dbb6aaf 100644 (file)
@@ -38,7 +38,7 @@ static void nft_queue_eval(const struct nft_expr *expr,
 
        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 {