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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 84119C43215 for ; Tue, 19 Nov 2019 20:14:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E73D2240E for ; Tue, 19 Nov 2019 20:14:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574194497; bh=LdeFR8HtAJeWIP3e9Vs/cKUSbteqaXMjyl1Ec8EruKk=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=KPPiRt+pkWLxc2upmkuGr1w6fH9SN070ByNGK0ZPieJc9BLQKaiHBmZI4XOOeECnA i+i4Ey8Zed1M43FYGkApYRJDMeQO9hSGGazYfM2cEvtLp1iMwQR0aTghy0Y2Jio2lx rHSJ7FaosB0lU/ucaYTank0IO1JjmhDC0JuJmRU0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727340AbfKSUO4 (ORCPT ); Tue, 19 Nov 2019 15:14:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:48508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726711AbfKSUO4 (ORCPT ); Tue, 19 Nov 2019 15:14:56 -0500 Received: from paulmck-ThinkPad-P72.home (unknown [199.201.64.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B175C22317; Tue, 19 Nov 2019 20:14:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574194494; bh=LdeFR8HtAJeWIP3e9Vs/cKUSbteqaXMjyl1Ec8EruKk=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=SwLovSoQhuIBOL/A5tJGPo/B7AbyFiPYw158oAxj6ucrg+7mTHw4C56LnFqltrVpY b6j3bhqfx762viVwIQkBKWNZXQTQqkP2Y4L+dOwLDHK2JuDRNT/wobwWi1Hh/uAxrd f2bg32TSgRmNM5oynZjwqvQb6LPlgmDb4vBWg/V4= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 4BC933520FA7; Tue, 19 Nov 2019 12:14:54 -0800 (PST) Date: Tue, 19 Nov 2019 12:14:54 -0800 From: "Paul E. McKenney" To: Marco Elver Cc: Qian Cai , Randy Dunlap , Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List , kasan-dev , Dmitry Vyukov Subject: Re: linux-next: Tree for Nov 19 (kcsan) Message-ID: <20191119201454.GE2889@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20191119194658.39af50d0@canb.auug.org.au> <20191119183407.GA68739@google.com> <1574190168.9585.4.camel@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 19, 2019 at 08:05:45PM +0100, Marco Elver wrote: > On Tue, 19 Nov 2019 at 20:02, Qian Cai wrote: > > > > On Tue, 2019-11-19 at 19:34 +0100, 'Marco Elver' via kasan-dev wrote: > > > On Tue, 19 Nov 2019, Randy Dunlap wrote: > > > > > > > On 11/19/19 8:12 AM, Marco Elver wrote: > > > > > On Tue, 19 Nov 2019 at 16:11, Randy Dunlap wrote: > > > > > > > > > > > > On 11/19/19 12:46 AM, Stephen Rothwell wrote: > > > > > > > Hi all, > > > > > > > > > > > > > > Changes since 20191118: > > > > > > > > > > > > > > > > > > > on x86_64: > > > > > > > > > > > > It seems that this function can already be known by the compiler as a > > > > > > builtin: > > > > > > > > > > > > ../kernel/kcsan/core.c:619:6: warning: conflicting types for built-in function ‘__tsan_func_exit’ [-Wbuiltin-declaration-mismatch] > > > > > > void __tsan_func_exit(void) > > > > > > ^~~~~~~~~~~~~~~~ > > > > > > > > > > > > > > > > > > $ gcc --version > > > > > > gcc (SUSE Linux) 7.4.1 20190905 [gcc-7-branch revision 275407] > > > > > > > > > > Interesting. Could you share the .config? So far I haven't been able > > > > > to reproduce. > > > > > > > > Sure, it's attached. > > > > > > Thanks, the config did the trick, even for gcc 9.0.0. > > > > > > The problem is CONFIG_UBSAN=y. We haven't explicitly disallowed it like > > > with KASAN. In principle there should be nothing wrong with KCSAN+UBSAN. > > > > > > There are 3 options: > > > 1. Just disable UBSAN for KCSAN, and also disable KCSAN for UBSAN. > > > 2. Restrict the config to not allow combining KCSAN and UBSAN. > > > 3. Leave things as-is. > > > > > > Option 1 probably makes most sense, and I'll send a patch for that > > > unless there are major objections. > > > > Both option #1 and #2 sounds quite unfortunate, as UBSAN is quite valuable for > > debugging. Hence, it is desire to make both work at the same time. > > Apologies, I think I was a bit unclear with #1. For #1, this just > means that UBSAN is being disabled for the KCSAN runtime and > vice-versa. All other parts of the kernel are still instrumented with > both. > > See here: https://lore.kernel.org/linux-next/20191119185742.GB68739@google.com/ Huh. This somehow got stuck into my non-urgent email. No idea why. Anyway, I applied and pushed it out on the kcsan branch of -rcu. Thanx, Paul