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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 C6152C4742C for ; Mon, 16 Nov 2020 18:20:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 829552078E for ; Mon, 16 Nov 2020 18:20:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731224AbgKPSUc (ORCPT ); Mon, 16 Nov 2020 13:20:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730441AbgKPSUc (ORCPT ); Mon, 16 Nov 2020 13:20:32 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DEDD4C0613CF for ; Mon, 16 Nov 2020 10:20:31 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1kej76-000803-KB; Mon, 16 Nov 2020 19:20:28 +0100 Date: Mon, 16 Nov 2020 19:20:28 +0100 From: Florian Westphal To: subashab@codeaurora.org Cc: Florian Westphal , pablo@netfilter.org, Sean Tranchetti , netfilter-devel@vger.kernel.org Subject: Re: [PATCH nf] x_tables: Properly close read section with read_seqcount_retry Message-ID: <20201116182028.GE22792@breakpoint.cc> References: <1605320516-17810-1-git-send-email-stranche@codeaurora.org> <20201114165330.GM23619@breakpoint.cc> <2ab4bcb63cbacba12ad927621fb56aab@codeaurora.org> <20201116141810.GB22792@breakpoint.cc> <8256f40ba9b73181f121baafe12cac61@codeaurora.org> <20201116170440.GA26150@breakpoint.cc> <983d178e6f3aac81d491362ab60db61f@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <983d178e6f3aac81d491362ab60db61f@codeaurora.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org subashab@codeaurora.org wrote: > > > Unfortunately we are seeing it on ARM64 regression systems which > > > runs a > > > variety of > > > usecases so the exact steps are not known. > > > > Ok. Would you be willing to run some of those with your suggested > > change to see if that resolves the crashes or is that so rare that this > > isn't practical? > > I can try that out. Let me know if you have any other suggestions as well > and I can try that too. > > I assume we cant add locks here as it would be in the packet processing > path. Yes. We can add a synchronize_net() in xt_replace_table if needed though, before starting to put the references on the old ruleset This would avoid the free of the jumpstack while skbs are still in-flight.