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=-14.2 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 5C7F5C432C3 for ; Thu, 14 Nov 2019 21:40:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31F3820709 for ; Thu, 14 Nov 2019 21:40:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KkzxVX4K" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727021AbfKNVkw (ORCPT ); Thu, 14 Nov 2019 16:40:52 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:40578 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726592AbfKNVkv (ORCPT ); Thu, 14 Nov 2019 16:40:51 -0500 Received: by mail-wr1-f65.google.com with SMTP id i10so8498568wrs.7 for ; Thu, 14 Nov 2019 13:40:50 -0800 (PST) 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=NJ5AXjvvGN3rmW3ly7bYsvI92wsOVyTwzutsVT4lLNU=; b=KkzxVX4KS4qUbANz1HTGSsWZdZzlQgYcP4L+xwokL21HbQezyUbqQ6EfS+GIrEojKW qolcEzO7f8J4GuMkwtVM0Vw+OWs6C/FquGDsmPYKp5GCBvQPLk0Ai2pgMo/yRGZSsW0R Hxp34epB4D9Xm5l9AZILC/g195nful0nHEODuXbTEtzsf4C/RqAjYi5YpZ+IhP+zk9co ExYstrLDd6SmytbC8Da/c+AzupNT/O3AYjIykxQuG5MKh2tKvXcznWVAlAjinThl7yDS egF7XKBOLWeLu+VGVtUXRHHTxS8g9JEHTPLmpcyqy1+P5UtKkk3/KEIcSe29aQas68ki HOFA== 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=NJ5AXjvvGN3rmW3ly7bYsvI92wsOVyTwzutsVT4lLNU=; b=EL6aZGZdwwx7SHVA+WGkCe3U5FhxBUo7q54zmMJWUDdRjuG5EA40PPQu0kfKBkfJyc LIZqZAKqUVQXxwmREWTi8EI8BZ8CVGLGxsuVDue5WCBYDbII9fwuE4MjNSs58xn+h5C1 XvW3IIFxgePEH92O/wmiC3syW4Zvdp1jZzQSM2y5Uga/i5mrP4M5QWfJoHmHBsBbZwe0 2faOGy8rFVKqvaPnfamEu+ZakiOrXho/G/HtNxL0edCrVjesO5LOufKmvFh5Z9a6+/mC usgPUHUXgGK24L3llAcv7rvvLsG+KYHT0pDVR4lFKGJC9PG/rAGfUSaJNnY4HIvDssK6 l5Qw== X-Gm-Message-State: APjAAAVflO+543vqlnq39fD4olcZ00IV2qOX5z2LlIOdW1FBn8KYzlWP ugrhVaShC4NS9Zcq1hfF+OTY3g== X-Google-Smtp-Source: APXvYqxkzPUiAzHpYfIdHWdk2kJMpAHkpms7E0w+/ME72VBfjNCIjRRJ9EpFjTlEbgwComBDbaQnbw== X-Received: by 2002:adf:ef91:: with SMTP id d17mr10599325wro.145.1573767190754; Thu, 14 Nov 2019 13:33:10 -0800 (PST) Received: from google.com ([100.105.32.75]) by smtp.gmail.com with ESMTPSA id i13sm8361956wrp.12.2019.11.14.13.33.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Nov 2019 13:33:09 -0800 (PST) Date: Thu, 14 Nov 2019 22:33:03 +0100 From: Marco Elver To: "Paul E. McKenney" Cc: akiyks@gmail.com, stern@rowland.harvard.edu, glider@google.com, parri.andrea@gmail.com, andreyknvl@google.com, luto@kernel.org, ard.biesheuvel@linaro.org, arnd@arndb.de, boqun.feng@gmail.com, bp@alien8.de, dja@axtens.net, dlustig@nvidia.com, dave.hansen@linux.intel.com, dhowells@redhat.com, dvyukov@google.com, hpa@zytor.com, mingo@redhat.com, j.alglave@ucl.ac.uk, joel@joelfernandes.org, corbet@lwn.net, jpoimboe@redhat.com, luc.maranget@inria.fr, mark.rutland@arm.com, npiggin@gmail.com, peterz@infradead.org, tglx@linutronix.de, will@kernel.org, edumazet@google.com, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [PATCH v4 00/10] Add Kernel Concurrency Sanitizer (KCSAN) Message-ID: <20191114213303.GA237245@google.com> References: <20191114180303.66955-1-elver@google.com> <20191114195046.GP2865@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191114195046.GP2865@paulmck-ThinkPad-P72> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 14 Nov 2019, Paul E. McKenney wrote: > On Thu, Nov 14, 2019 at 07:02:53PM +0100, Marco Elver wrote: > > This is the patch-series for the Kernel Concurrency Sanitizer (KCSAN). > > KCSAN is a sampling watchpoint-based *data race detector*. More details > > are included in **Documentation/dev-tools/kcsan.rst**. This patch-series > > only enables KCSAN for x86, but we expect adding support for other > > architectures is relatively straightforward (we are aware of > > experimental ARM64 and POWER support). > > > > To gather early feedback, we announced KCSAN back in September, and have > > integrated the feedback where possible: > > http://lkml.kernel.org/r/CANpmjNPJ_bHjfLZCAPV23AXFfiPiyXXqqu72n6TgWzb2Gnu1eA@mail.gmail.com > > > > The current list of known upstream fixes for data races found by KCSAN > > can be found here: > > https://github.com/google/ktsan/wiki/KCSAN#upstream-fixes-of-data-races-found-by-kcsan > > > > We want to point out and acknowledge the work surrounding the LKMM, > > including several articles that motivate why data races are dangerous > > [1, 2], justifying a data race detector such as KCSAN. > > > > [1] https://lwn.net/Articles/793253/ > > [2] https://lwn.net/Articles/799218/ > > I queued this and ran a quick rcutorture on it, which completed > successfully with quite a few reports. Great. Many thanks for queuing this in -rcu. And regarding merge window you mentioned, we're fine with your assumption to targeting the next (v5.6) merge window. I've just had a look at linux-next to check what a future rebase requires: - There is a change in lib/Kconfig.debug and moving KCSAN to the "Generic Kernel Debugging Instruments" section seems appropriate. - bitops-instrumented.h was removed and split into 3 files, and needs re-inserting the instrumentation into the right places. Otherwise there are no issues. Let me know what you recommend. Thanks, -- Marco