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=-13.1 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=ham 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 1F996C433DF for ; Thu, 25 Jun 2020 19:35:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E97972076E for ; Thu, 25 Jun 2020 19:35:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cZx1Jl3k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406669AbgFYTfm (ORCPT ); Thu, 25 Jun 2020 15:35:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405815AbgFYTfl (ORCPT ); Thu, 25 Jun 2020 15:35:41 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 629F1C08C5C1 for ; Thu, 25 Jun 2020 12:35:41 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id r12so7041050wrj.13 for ; Thu, 25 Jun 2020 12:35:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=338KiFmHj0j9aEP9OnwhZQhzwCpeImYEtfOmTA/bECk=; b=cZx1Jl3kF6Z3T9JrekfYLiqxZZVEEyfVJwWfYCcpEu7dOn5mjB2XQbR4eZrpFUZKE7 FhQzgOFEXpD5Z8Ifa6k8GcVLaj61pIP/S3PrvFi29pspMw8uW3p4Q7RskTgmCh9hN924 vmL5PYWJfs+a0CnZKLfNob1DXN4Rpj2LvM/3zFXIhDa7Cx6IboTCUVntFxntCuUphqJv KrHCVa6RvJm0YffFTkvt7fviIOH6l9iKr/zG2YNwonNvC66EO6ayWkZ8r00F0L0vbKw6 pYglt3O4wOUUfrEZhbpLT3kWHjBFwQsUlCIx3C4gYO3D3qMUkAz5YG+nvpHvq9fV4rpb 4LEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=338KiFmHj0j9aEP9OnwhZQhzwCpeImYEtfOmTA/bECk=; b=aYgCVTzzAAZZcY5JOKVdJWETLCC2SksTLQF1jY4LF1Cbn4HT5FMK5XkOq3I6rDmzbJ OafzaTqQ0gAQYhU8LlmfY0neMuF/pIpGoVR5iT0dqhLVYprCJ4sybINacSZLYWrRA8JW KJC4ZMiN3ohVKk3hBk+mtAk+8hnRwRaJZYNajftzmREJWDNoykpbRPsJgDZggoG8GlZy f1eF5tyEhpCETswLRN6b/rJiw4TF5UwlFAg3XQplSthS0Itin/s6UOszT+SNs4raTxPT 4cpixBZmDjUswbtrcAplEx/xrhQDS6x6W+3RkJ4tun/1h854oxxZZnIY2ZCEeZtQ5vmc ZK4Q== X-Gm-Message-State: AOAM5332a80gMG4R6jaAfOHSOqrnx1b9VeqAEumMqYalvtj/bd8F9a0v u4udlwigoxwMPX84DzVlNGdSng== X-Google-Smtp-Source: ABdhPJxXQCiliAoYKTeewMcMPDSdS7kEFDo4jnOWAuwf5M8B9OiUbIFbW63E/C7X/4+hYX6z+i4l8g== X-Received: by 2002:a5d:458a:: with SMTP id p10mr33140763wrq.184.1593113739967; Thu, 25 Jun 2020 12:35:39 -0700 (PDT) Received: from elver.google.com ([100.105.32.75]) by smtp.gmail.com with ESMTPSA id t4sm7862891wmf.4.2020.06.25.12.35.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jun 2020 12:35:39 -0700 (PDT) Date: Thu, 25 Jun 2020 21:35:33 +0200 From: Marco Elver To: Peter Zijlstra Cc: "Paul E. McKenney" , kernel test robot , kbuild-all@lists.01.org, LKML , Will Deacon , Mark Rutland Subject: Re: [rcu:rcu/next 35/35] kernel/rcu/tree.c:251:8: error: implicit declaration of function 'arch_atomic_add_return'; did you mean Message-ID: <20200625193533.GA235320@elver.google.com> References: <202006250300.ic32FsdY%lkp@intel.com> <20200624203025.GJ9247@paulmck-ThinkPad-P72> <20200625112926.GO4781@hirez.programming.kicks-ass.net> <20200625141125.GE117543@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200625141125.GE117543@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.13.2 (2019-12-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 25, 2020 at 04:11PM +0200, Peter Zijlstra wrote: > On Thu, Jun 25, 2020 at 01:29:26PM +0200, Peter Zijlstra wrote: > > I fear the same. Let me see if I can quickly modify the atomic scripts > > to generate the required fallbacks. > > Something like so ought to work, I suppose. > > --- > Subject: locking/atomics: Provide the arch_atomic_ interface to generic code > From: Peter Zijlstra > Date: Thu Jun 25 15:55:14 CEST 2020 > > Architectures with instrumented (KASAN/KCSAN) atomic operations > natively provide arch_atomic_ variants that are not instrumented. > > It turns out that some generic code also requires arch_atomic_ in > order to avoid instrumentation, so provide the arch_atomic_ interface > as a direct map into the regular atomic_ interface for > non-instrumented architectures. > > Signed-off-by: Peter Zijlstra (Intel) > --- > include/linux/atomic-fallback.h | 236 +++++++++++++++++++++++++++++++++- > scripts/atomic/gen-atomic-fallback.sh | 31 ++++ > 2 files changed, 266 insertions(+), 1 deletion(-) Thanks, looks reasonable! If noinstr becomes important on architectures that don't implement atomics using arch_ themselves, there might be a problem with CONFIG_TRACE_BRANCH_PROFILING, because unlikely() is used throughout this file. Probably not something to worry about now. Thanks, -- Marco