From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [Patch net-next 3/5] net_sched: fix suspicious RCU usage in tcindex_classify() Date: Mon, 15 Sep 2014 14:29:45 -0700 Message-ID: <54175A49.3040905@intel.com> References: <1410815210-6693-1-git-send-email-xiyou.wangcong@gmail.com> <1410815210-6693-4-git-send-email-xiyou.wangcong@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: john.fastabend@gmail.com, "David S. Miller" To: Cong Wang , netdev@vger.kernel.org Return-path: Received: from mga02.intel.com ([134.134.136.20]:45198 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753874AbaIOV3r (ORCPT ); Mon, 15 Sep 2014 17:29:47 -0400 In-Reply-To: <1410815210-6693-4-git-send-email-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 09/15/2014 02:06 PM, Cong Wang wrote: > This patch fixes the following kernel warning: > > [ 44.805900] [ INFO: suspicious RCU usage. ] > [ 44.808946] 3.17.0-rc4+ #610 Not tainted > [ 44.811831] ------------------------------- > [ 44.814873] net/sched/cls_tcindex.c:84 suspicious rcu_dereference_check() usage! > > Fixes: commit 331b72922c5f58d48fd ("net: sched: RCU cls_tcindex") > Cc: John Fastabend > Signed-off-by: Cong Wang > --- > net/sched/cls_tcindex.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c > index 16ec1ed..f276de5 100644 > --- a/net/sched/cls_tcindex.c > +++ b/net/sched/cls_tcindex.c > @@ -81,7 +81,7 @@ tcindex_lookup(struct tcindex_data *p, u16 key) > static int tcindex_classify(struct sk_buff *skb, const struct tcf_proto *tp, > struct tcf_result *res) > { > - struct tcindex_data *p = rcu_dereference(tp->root); > + struct tcindex_data *p = rcu_dereference_bh(tp->root); > struct tcindex_filter_result *f; > int key = (skb->tc_index & p->mask) >> p->shift; > > Thanks for catching/fixing. I also missed cls_bpf.c case I'll send a fix in a moment. Acked-by: John Fastabend