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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 2C8F7C2BA12 for ; Fri, 3 Apr 2020 19:49:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBCDE20B1F for ; Fri, 3 Apr 2020 19:49:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585943380; bh=pR6uHP6JFEAqfjhply3d26wZntgYfJrsAOcrtwEDQu0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=vqZ0doSz8Kd0ICEVjqAQzjLi85Pv2D6v1Aw1BlC8EMUtX2g001LP0UKlHQKT8ssLR YofBLr8RhJD319EVAPySfsXBVY4sgf4VpDh6+p20XhD63iOQoI7E6+PQs4pkfhrSJE I338S8HQa6yBoU9tEoa14VDCflM9S7HsrQHsRyWE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727809AbgDCTtg (ORCPT ); Fri, 3 Apr 2020 15:49:36 -0400 Received: from mail-pj1-f65.google.com ([209.85.216.65]:35801 "EHLO mail-pj1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726460AbgDCTtf (ORCPT ); Fri, 3 Apr 2020 15:49:35 -0400 Received: by mail-pj1-f65.google.com with SMTP id g9so3430516pjp.0; Fri, 03 Apr 2020 12:49:33 -0700 (PDT) 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=x2pc80oThxV6qNBWGlmeKcETWFQG6BcGqDuUp7g6seI=; b=C2saI+xzCvwnV/1XYD57j0sd03Kn0Pxvtx0U7LSuL39D94znfofRiE65lLXz2BjhDb ppwov8P+H4mup/f1IOY+nD9v+F17EJzl9xLqq/eGvKuvujph/qcIYeg8LTDu+KCdkK15 PnMP8bBvdBv4a6Wd/x8C0yiTlqYURftz+qC+MHHF1x7YoiqE6186o3w6xegfGc1ljRP1 3WxAjnRE+eXoIS6mUAek9fyadSb8Je0j8NK2o2SWOBHwkOmB8AT0TmmSKtN7ASvrImlY edqvZv62PWOKZpAaYEo+MeYxPzi0phmf+VV61WROu3c6+WzcSmqINOCh68rxWSZOv85i sGGw== X-Gm-Message-State: AGi0PuaMllxoXgSxG/EOMODA2oIhpN248rPMCnnRqhDLfocpVsbw7iR8 qy8+bBoGOQf8F/tRtI8Wa0c= X-Google-Smtp-Source: APiQypJ+IXj4OXk7K8o38nrR2hClG27wXJLbJPmZCN3t6HqOTaFX1aLIqDevdMmiOCGfeqtU7eugyg== X-Received: by 2002:a17:902:8b82:: with SMTP id ay2mr9227374plb.221.1585943372496; Fri, 03 Apr 2020 12:49:32 -0700 (PDT) Received: from 42.do-not-panic.com (42.do-not-panic.com. [157.230.128.187]) by smtp.gmail.com with ESMTPSA id ml17sm6443717pjb.13.2020.04.03.12.49.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Apr 2020 12:49:30 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id 7938E40297; Fri, 3 Apr 2020 19:49:29 +0000 (UTC) Date: Fri, 3 Apr 2020 19:49:29 +0000 From: Luis Chamberlain To: Bart Van Assche Cc: Ming Lei , axboe@kernel.dk, viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org, rostedt@goodmis.org, mingo@redhat.com, jack@suse.cz, nstange@suse.de, mhocko@suse.com, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com Subject: Re: [RFC 0/3] block: address blktrace use-after-free Message-ID: <20200403194929.GZ11244@42.do-not-panic.com> References: <20200402000002.7442-1-mcgrof@kernel.org> <20200403081929.GC6887@ming.t460p> <15236c59-6b48-2fcf-1a84-f98cb8b339ab@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15236c59-6b48-2fcf-1a84-f98cb8b339ab@acm.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Apr 03, 2020 at 07:13:47AM -0700, Bart Van Assche wrote: > On 2020-04-03 01:19, Ming Lei wrote: > > BTW, Yu Kuai posted one patch for this issue, looks that approach > > is simpler: > > > > https://lore.kernel.org/linux-block/20200324132315.22133-1-yukuai3@huawei.com/ > > That approach is indeed simpler but at the expense of performing dynamic > memory allocation in a cleanup path, something I'm not enthusiast about. I also think that its important to annotate that there are actually two issues here. Not one. One is the misuse of debugfs, the other is how the deferral exposed the misuse and complications of its misuse. Luis