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[209.132.180.67]) by mx.google.com with ESMTP id w16si64306435pga.328.2019.01.08.16.38.28; Tue, 08 Jan 2019 16:38:43 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=KO9rxOWB; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728790AbfAIAhA (ORCPT + 99 others); Tue, 8 Jan 2019 19:37:00 -0500 Received: from mail-vs1-f51.google.com ([209.85.217.51]:33196 "EHLO mail-vs1-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727829AbfAIAhA (ORCPT ); Tue, 8 Jan 2019 19:37:00 -0500 Received: by mail-vs1-f51.google.com with SMTP id p74so3724505vsc.0 for ; Tue, 08 Jan 2019 16:36:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yf6VfMJCkyhGkyRtOpkGcrGu7K1Ywv/nC95vYdFwPO4=; b=KO9rxOWByo6OzbDroi8xLBYeZzJqW8PKyXC+GSixSHLMuuDfb6vg0TNQLGtS2w+NGH hH4VfD56sBoHcmNyqEAcTwoGBjKGOIL/1yPqCoVU6K8d84WB+ZihN1fZX5nRF5bk6/My ZJtHx/8iFlUbE+cVSONqooIXDgxMlZFvJmstBBvZHBMZsFHlwzuOKM4blC+gkBW2Uc8G Crnhepnj2FauLpH3fyzNjMRpn82LwG/VINjHL1+UQrSMrjE1B+PwuMQsl6wjYpjEBkSQ RqaPw9X6ZeS6RYjDxYT4MhdG2XDW/xGmc0Cnpcc4yGzH/bXyY/zgeuWOVE0az69TUE+n o8HQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yf6VfMJCkyhGkyRtOpkGcrGu7K1Ywv/nC95vYdFwPO4=; b=l5K5zP/23SPksv66vovqF0fFTddccoIeVaDxe+5DFR2FdbDeGtA4G6K834XV20vFk6 MZG+6OGiHvxT5gDGRYHx20BqS28O3B2lM89Asd+bJgcwJYqEWc+dtdtmncZZQkpBlcql myJ8oIgm9dcwP1rQOdcZZoIOU1BDin3oFfy0Ryb2CcpEyl8LTyvaTGPUdWD8RfRzPWT8 c0G9sJyOF8A+VK/9OuIOd2akWWiGVZ7bZz2iYrtsepfDLdd5FkFWyum/GAz5eY3DWKQH RYBVi3ZFAMtPWT1p7gYPzSR61QFGbQz/OuNvja9K5HHv/vmDv1toKzxKgWo6IL9LwLpN 1S+Q== X-Gm-Message-State: AJcUukdfIftteOAC6nLmYVAhCT8NeVoPoNJOUgLTb/8/coPVf50/JfS0 dL6lketo673hsADoX3uca8PwsyjNxWUr3j4oOBs= X-Received: by 2002:a67:3e12:: with SMTP id l18mr1659562vsa.53.1546994218551; Tue, 08 Jan 2019 16:36:58 -0800 (PST) MIME-Version: 1.0 References: <20190109000214.GA5907@andrea> In-Reply-To: <20190109000214.GA5907@andrea> From: Anatol Pomozov Date: Tue, 8 Jan 2019 16:36:46 -0800 Message-ID: Subject: Re: seqcount usage in xt_replace_table() To: Andrea Parri Cc: fw@strlen.de, Dmitry Vyukov , Paul McKenney , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello On Tue, Jan 8, 2019 at 4:02 PM Andrea Parri wrote: > > Hi Anatol, > > On Tue, Jan 08, 2019 at 11:33:39AM -0800, Anatol Pomozov wrote: > > Hello folks, > > > > A bit of context what I am doing. I am trying to port KTSAN (Kernel > > Thread Sanitizer) tool to v4.20. That tool tracks shared data usage > > and makes sure it is accessed in a thread-safe manner. > > Interesting! FYI, some LKMM's maintainers (Paul included) had and > continued to have some "fun" discussing topics related to "thread- > safe memory accesses": I'm sure that they'll be very interested in > such work of yours and eager to discuss your results. Thread Sanitizer is a great tool to find thread-safety issues with user-space code. The tool been developed by a team of smart people from Google [1]. KTSAN is an attempt to bring the same ideas to Linux kernel [2]. A bunch of work been done there but the project is still at proof-of-concept point. I am not a part of Google's dynamic tools team. But I've decided to pick something to do during the New Year holidays so started porting KTSAN from v4.2 to v4.20. The work is "almost completed" but I need to fix a few crashes [3]. [1] https://github.com/google/sanitizers [2] https://github.com/google/ktsan/wiki [3] https://github.com/anatol/linux/tree/ktsan_4.20