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=-7.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 55FEEC43387 for ; Wed, 9 Jan 2019 11:24:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E324217F9 for ; Wed, 9 Jan 2019 11:24:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="Qzmh+etT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730647AbfAILYl (ORCPT ); Wed, 9 Jan 2019 06:24:41 -0500 Received: from mail-ed1-f67.google.com ([209.85.208.67]:39999 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729843AbfAILYk (ORCPT ); Wed, 9 Jan 2019 06:24:40 -0500 Received: by mail-ed1-f67.google.com with SMTP id g22so6981847edr.7 for ; Wed, 09 Jan 2019 03:24:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=LUhYFMnYK7TypITgbyRnAJd8zP8Pz991VZzwgNQwYeM=; b=Qzmh+etTP1/CVAoMadrJ3qZbdFCSwwuL+f+uc2nmPjFdXjLItbAAwquDBQOLPfB6d2 rYVOPR1WnajGBkqN08KCPDkSNF9qbvvF+GUBpoBPEnuuqXeRYp8u2DUCTc3R1n1nib6c nLzmE0tz8Qp4C+K8DKXLZxO+V9ZNnH1/GkNKI= 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=LUhYFMnYK7TypITgbyRnAJd8zP8Pz991VZzwgNQwYeM=; b=PRR8XjIrgc/QQ4qnqtk54VXNZkxXiWY0OjlyGU64vTeERambLt5WQRZXvYIjjYpJ1e oXYqWLgFgOm86/PJZ3XjMbcrXx0lZ86+xxi62Enor6SBeBvrSQxVYAVxPuik5lme+Pvf hzRZiDO2cEiGX1b4jqsxjX3qHl6ZffrXpQHM3Ubg4JicOueODLdA8fEyUz2s6BkidNGN nwMEvBU+mD0FkvlZuIFmJ2fsWLyrYqIEWabj7bvS7WlOWyPHzDn969JCBgN59sE9Xexh 3VVDRdaYdpWZy6u5H0vpzGRw76leK7u8tqhi63oeaLi7VZQc9OJcJxBQIdI68ydWbnUp 7lOw== X-Gm-Message-State: AJcUukc2SFDvu/RCYIU5EzNcd5NAG43Pvxda1g5sjCwOJvv4DJN74rgG 6CC4PGYoLhZpTl6V/sHqqiYbmA== X-Google-Smtp-Source: ALg8bN5VV4Ch+i0YqmapN3/el3yA9cef6wxy9AOjmVMqGqrtMmVX8euThxuvDuSLUz7sH8HpTF3SMQ== X-Received: by 2002:aa7:c152:: with SMTP id r18mr5744708edp.258.1547033078973; Wed, 09 Jan 2019 03:24:38 -0800 (PST) Received: from andrea (86.100.broadband17.iol.cz. [109.80.100.86]) by smtp.gmail.com with ESMTPSA id r1sm909432eds.1.2019.01.09.03.24.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 09 Jan 2019 03:24:38 -0800 (PST) Date: Wed, 9 Jan 2019 12:24:32 +0100 From: Andrea Parri To: Anatol Pomozov Cc: fw@strlen.de, Dmitry Vyukov , Paul McKenney , LKML , Andrey Konovalov Subject: Re: seqcount usage in xt_replace_table() Message-ID: <20190109112432.GA6351@andrea> References: <20190109000214.GA5907@andrea> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 08, 2019 at 04:36:46PM -0800, Anatol Pomozov wrote: > 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. Yes, I have been aware of these tools since at least ;-) https://groups.google.com/forum/#!msg/ktsan/bVZ1c6H2NE0/Dxrw55bfBAAJ > > 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]. I guess my first reaction would remain "it's kind of hard (to use an euphemism) to review 7,582 additions or so for a data race detector without a clear/an accepted (by the community) notion of data race..." Andrea > > [1] https://github.com/google/sanitizers > [2] https://github.com/google/ktsan/wiki > [3] https://github.com/anatol/linux/tree/ktsan_4.20