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 CC072C2D0A3 for ; Mon, 16 Nov 2020 17:05:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CF5220789 for ; Mon, 16 Nov 2020 17:05:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732415AbgKPREo (ORCPT ); Mon, 16 Nov 2020 12:04:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbgKPREn (ORCPT ); Mon, 16 Nov 2020 12:04:43 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE96DC0613CF for ; Mon, 16 Nov 2020 09:04:43 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1kehvk-0007U2-QU; Mon, 16 Nov 2020 18:04:40 +0100 Date: Mon, 16 Nov 2020 18:04:40 +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: <20201116170440.GA26150@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8256f40ba9b73181f121baafe12cac61@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: > > Is that to order wrt. seqcount_sequence? > > Correct, we want to ensure that the table->private is updated and is > in sync on all CPUs beyond that point. > > > Do you have a way to reproduce such crashes? > > > > I tried to no avail but I guess thats just because amd64 is more > > forgiving. > > > > Thanks! > > 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?