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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 094DFC433E0 for ; Tue, 19 May 2020 22:05:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1AB4206C3 for ; Tue, 19 May 2020 22:05:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727924AbgESWFP (ORCPT ); Tue, 19 May 2020 18:05:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725885AbgESWFO (ORCPT ); Tue, 19 May 2020 18:05:14 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F100C061A0F for ; Tue, 19 May 2020 15:05:14 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jbAMH-0003FU-EL; Wed, 20 May 2020 00:05:09 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id B6FD5100606; Wed, 20 May 2020 00:05:08 +0200 (CEST) From: Thomas Gleixner To: Qian Cai , Marco Elver Cc: Peter Zijlstra , Linux Kernel Mailing List , kasan-dev , Will Deacon , "Paul E . McKenney" , Ingo Molnar Subject: Re: [PATCH] READ_ONCE, WRITE_ONCE, kcsan: Perform checks in __*_ONCE variants In-Reply-To: References: <20200512183839.2373-1-elver@google.com> <20200512190910.GM2957@hirez.programming.kicks-ass.net> Date: Wed, 20 May 2020 00:05:08 +0200 Message-ID: <87y2pn60ob.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Qian Cai writes: > On Tue, May 19, 2020 at 5:26 PM Marco Elver wrote: >> The new solution is here: >> https://lkml.kernel.org/r/20200515150338.190344-1-elver@google.com >> While it's a little inconvenient that we'll require Clang 11 >> (currently available by building yourself from LLVM repo), but until >> we get GCC fixed (my patch there still pending :-/), this is probably >> the right solution going forward. If possible, please do test! > > That would be quite unfortunate. The version here is still gcc-8.3.1 > and clang-9.0.1 on RHEL 8.2 here. It will probably need many years to > be able to get the fixed compilers having versions that high. Sigh... > Also, I want to avoid compiling compilers on my own. Yes, it's unfortunate, but we have to stop making major concessions just because tools are not up to the task. We've done that way too much in the past and this particular problem clearly demonstrates that there are limits. Making brand new technology depend on sane tools is not asked too much. And yes, it's inconvenient, but all of us have to build tools every now and then to get our job done. It's not the end of the world. Building clang is trivial enough and pointing the make to the right compiler is not rocket science either. Thanks, tglx