From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B71EEC2BA19 for ; Mon, 6 Apr 2020 09:03:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F1702078C for ; Mon, 6 Apr 2020 09:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726841AbgDFJDb (ORCPT ); Mon, 6 Apr 2020 05:03:31 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:43986 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726533AbgDFJDa (ORCPT ); Mon, 6 Apr 2020 05:03:30 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id A047820523; Mon, 6 Apr 2020 11:03:28 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3hYAfdPan_2n; Mon, 6 Apr 2020 11:03:28 +0200 (CEST) Received: from cas-essen-01.secunet.de (201.40.53.10.in-addr.arpa [10.53.40.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 3730D2051F; Mon, 6 Apr 2020 11:03:28 +0200 (CEST) Received: from gauss2.secunet.de (10.182.7.193) by cas-essen-01.secunet.de (10.53.40.201) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 6 Apr 2020 11:03:28 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 9DCB53180093; Mon, 6 Apr 2020 11:03:27 +0200 (CEST) Date: Mon, 6 Apr 2020 11:03:27 +0200 From: Steffen Klassert To: Yuehaibing CC: , , , , Subject: Re: [PATCH net-next] xfrm: policy: Remove obsolete WARN while xfrm policy inserting Message-ID: <20200406090327.GF13121@gauss3.secunet.de> References: <20200327123443.12408-1-yuehaibing@huawei.com> <20200328112302.GA13121@gauss3.secunet.de> <1d3596fb-c7e3-16c9-f48f-fe58e9a2569a@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1d3596fb-c7e3-16c9-f48f-fe58e9a2569a@huawei.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-ClientProxiedBy: cas-essen-01.secunet.de (10.53.40.201) To cas-essen-01.secunet.de (10.53.40.201) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 30, 2020 at 10:05:32PM +0800, Yuehaibing wrote: > On 2020/3/28 19:23, Steffen Klassert wrote: > > On Fri, Mar 27, 2020 at 08:34:43PM +0800, YueHaibing wrote: > >> Since commit 7cb8a93968e3 ("xfrm: Allow inserting policies with matching > >> mark and different priorities"), we allow duplicate policies with > >> different priority, this WARN is not needed any more. > > > > Can you please describe a bit more detailed why this warning > > can't trigger anymore? > > No, this warning is triggered while detect a duplicate entry in the policy list > > regardless of the priority. If we insert policy like this: > > policy A (mark.v = 3475289, mark.m = 0, priority = 1) //A is inserted > policy B (mark.v = 0, mark.m = 0, priority = 0) //B is inserted > policy C (mark.v = 3475289, mark.m = 0, priority = 0) //C is inserted and B is deleted The codepath that replaces a policy by another should just trigger on policy updates (XFRM_MSG_UPDPOLICY). Is that the case in your test? It should not be possible to add policy C with XFRM_MSG_NEWPOLICY as long as you have policy B inserted. The update replaces an old policy by a new one, the lookup keys of the old policy must match the lookup keys of the new one. But policy B has not the same lookup keys as C, the mark is different. So B should not be replaced with C. > policy D (mark.v = 3475289, mark.m = 0, priority = 1) > > while finding delpol in xfrm_policy_insert_list, > first round delpol is matched C, whose priority is less than D, so contiue the loop, > then A is matched， WARN_ON is triggered. It seems the WARN is useless. Looks like the warning is usefull, it found a bug.