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=-12.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PULL_REQUEST,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 33F4FC433E0 for ; Fri, 26 Jun 2020 04:12:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F23DC20775 for ; Fri, 26 Jun 2020 04:12:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593144754; bh=mH3fgegvAMw88KIXqT9GoWN67oTIoBSRBIWsIiPCOXI=; h=Date:From:To:Cc:Subject:Reply-To:List-ID:From; b=o0A3HBQ9Ddx9ofsz5fofxOG8U56gf0OMhqQNCkwADhUTbMQVR0Qk9C5UXjW6NNwt9 mwEbwbNukB1S9SkUtu7NhPsd7u5f/n6X5NVlUo65miX/jDtwu9u0FAhtSLjGB/qqIM gb4jMl05dvAGPTLbzedOW+UNaEeMiC/u55U+TKkM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726479AbgFZEMd (ORCPT ); Fri, 26 Jun 2020 00:12:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:58276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726013AbgFZEMd (ORCPT ); Fri, 26 Jun 2020 00:12:33 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (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 EEF2920767; Fri, 26 Jun 2020 04:12:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593144753; bh=mH3fgegvAMw88KIXqT9GoWN67oTIoBSRBIWsIiPCOXI=; h=Date:From:To:Cc:Subject:Reply-To:From; b=oRA1sQ2M/IlPQMQjhu7uqq1gDrDoXQ/ZOv0I3w+Rk2Mq7zcoBn/rbU2wyrm4Gd/vD XZew+OupN+c8tZd0fC1u5KZMtKP1KCDCooey6WLgIOladrhtdBUW1hmwzrz1hkIR4i qr8xnxZinLvIPxpHcbbtKWu+4+86cYOzLqZ0mn7Y= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id D342B3523611; Thu, 25 Jun 2020 21:12:32 -0700 (PDT) Date: Thu, 25 Jun 2020 21:12:32 -0700 From: "Paul E. McKenney" To: mingo@kernel.org, tglx@linutronix.de Cc: peterz@infradead.org, x86@kernel.org, elver@google.com, linux-kernel@vger.kernel.org, rcu@vger.kernel.org Subject: [GIT RFC PULL rcu/urgent] Fix noinstr warnings for KCSAN Message-ID: <20200626041232.GA10544@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Hello! This pull request contains a single commit that uses "arch_" atomic operations to avoid the instrumentation that comes with the non-"arch_" versions. In preparation for that commit, it also has another commit that makes these "arch_" atomic operations available to generic code. Without these commits, KCSAN uses can see pointless errors. This pull request is currently RFC pending ongoing -next testing. This was not entirely free of drama, with Stephen needing to handle a merge conflict: https://lore.kernel.org/lkml/20200626131425.73ee4e27@canb.auug.org.au/ However, the resolution looks straightforward to me. In addition, these two commits pass rcutorture testing and associated KCSAN testing. The following changes since commit b3a9e3b9622ae10064826dccb4f7a52bd88c7407: Linux 5.8-rc1 (2020-06-14 12:45:04 -0700) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/urgent for you to fetch changes up to b58e733fd774f3f4b49d9e7640d172a57e35200e: rcu: Fixup noinstr warnings (2020-06-25 08:24:32 -0700) ---------------------------------------------------------------- Peter Zijlstra (2): locking/atomics: Provide the arch_atomic_ interface to generic code rcu: Fixup noinstr warnings include/linux/atomic-fallback.h | 236 +++++++++++++++++++++++++++++++++- include/linux/compiler.h | 2 +- kernel/rcu/tree.c | 32 ++++- scripts/atomic/gen-atomic-fallback.sh | 31 +++++ 4 files changed, 292 insertions(+), 9 deletions(-)