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=-5.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 3E32EC47082 for ; Thu, 3 Jun 2021 15:46:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AB19613BF for ; Thu, 3 Jun 2021 15:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229692AbhFCPsU (ORCPT ); Thu, 3 Jun 2021 11:48:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229617AbhFCPsT (ORCPT ); Thu, 3 Jun 2021 11:48:19 -0400 Received: from mail-il1-x129.google.com (mail-il1-x129.google.com [IPv6:2607:f8b0:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 227C8C06174A for ; Thu, 3 Jun 2021 08:46:19 -0700 (PDT) Received: by mail-il1-x129.google.com with SMTP id d1so2960362ils.5 for ; Thu, 03 Jun 2021 08:46:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=8YcBVNckt87HVYyLs2knwYKQtGbIl14b368u5y324YQ=; b=setdzS9B3oPv5TR64ZzJpXvy218Ig4yMo8+Wy9C0kPdW1q8LGlAGFyXNxRnXbfvEhS +Bmr0XHw07v0DQTioERnt//X4juNuOp0fWuQ9eB9gPm4dhftvw68gqPLw+dGu+LTHi5b jp6RKvpfi94saetnUGvJrRoPpgAKA+xuqhnshGB+9sqbq83FqClV5BY59VEZxkR5tmIE H+bp7hroUyDn7yP6ALI7sugX6ZqrNN1pvJMc4ptXGDI9W0tlvbouIkmy+7ndm3P3sARk DuOWwJztAI5fFacGPug4ZQbNM3K1I/RoOjfjrt0uf63IoY0StEZ9iIZNONyVx1h5x1qH dSxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=8YcBVNckt87HVYyLs2knwYKQtGbIl14b368u5y324YQ=; b=mt5uEyJj9+/W6CXkSgrf9M+wefRM+XSElblevbxKB520MRLHqALtNqd6rP+krpNAHx fhaBp01+UPTVo3tXWobIcxL7tWieHffaUHv2aMMSbR7JSeBtQA/AjKs/l4xyPi4jrOq4 hgKyNzLBFg5cL5jNCVR1kKA4HfZaILjFlfcpX/WTtZIbBOe1k/1ZcQITzEao6L/5sD8F v6XFuptLD2K13um91V2NAwASWnBU5Vbzlc18LyGtho4jmCZaEwCOsCNy/Ya6J/tlYWY2 rR9MT81qQccS0iH496dwaEtdZGzE56Mx9WLkp89/4AJL9PCubdG85okWqKzOMUCYtXlv XU6g== X-Gm-Message-State: AOAM532wmuPjP2uRchgMSKMweOpKV/ustwIlkjHdn1q9QvxczfNLJQQ+ jTGmYBtDcJqPT3xmwrvMTcMqNw== X-Google-Smtp-Source: ABdhPJw4z+lsn3Ie3mWZtiwjDbIktt/3jyiRQtJbj9iC7+2VghLkIgzAaWCsQonUtFffb6lfD4Edjw== X-Received: by 2002:a92:3610:: with SMTP id d16mr42958ila.16.1622735178319; Thu, 03 Jun 2021 08:46:18 -0700 (PDT) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id p81sm1890651iod.0.2021.06.03.08.46.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 03 Jun 2021 08:46:17 -0700 (PDT) Subject: Re: [PATCH] io_uring: Remove CONFIG_EXPERT To: Justin Forbes , Justin Forbes Cc: asml.silence@gmail.com, io-uring@vger.kernel.org, Linux Kernel Mailing List References: <20210526223445.317749-1-jforbes@fedoraproject.org> <01c2a63f-23f6-2228-264d-6f3e581e647d@kernel.dk> From: Jens Axboe Message-ID: <73673ab9-9ec7-611f-b1f0-5394cd7a172c@kernel.dk> Date: Thu, 3 Jun 2021 09:46:17 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 6/3/21 9:43 AM, Justin Forbes wrote: > On Thu, May 27, 2021 at 11:01 AM Justin Forbes wrote: >> >> On Thu, May 27, 2021 at 9:19 AM Jens Axboe wrote: >>> >>> On 5/27/21 8:12 AM, Justin Forbes wrote: >>>> On Thu, May 27, 2021 at 8:43 AM Jens Axboe wrote: >>>>> >>>>> On 5/26/21 4:34 PM, Justin M. Forbes wrote: >>>>>> While IO_URING has been in fairly heavy development, it is hidden behind >>>>>> CONFIG_EXPERT with a default of on. It has been long enough now that I >>>>>> think we should remove EXPERT and allow users and distros to decide how >>>>>> they want this config option set without jumping through hoops. >>>>> >>>>> The whole point of EXPERT is to ensure that it doesn't get turned off >>>>> "by accident". It's a core feature, and something that more and more >>>>> apps or libraries are relying on. It's not something I intended to ever >>>>> go away, just like it would never go away for eg futex or epoll support. >>>>> >>>> >>>> I am not arguing with that, I don't expect it will go away. I >>>> certainly do not have an issue with it defaulting to on, and I didn't >>>> even submit this with intention to turn it off for default Fedora. I >>>> do think that there are cases where people might not wish it turned on >>>> at this point in time. Hiding it behind EXPERT makes it much more >>>> difficult than it needs to be. There are plenty of config options >>>> that are largely expected default and not hidden behind EXPERT. >>> >>> Right there are, but not really core kernel features like the ones >>> I mentioned. Hence my argument for why it's correct as-is and I >>> don't think it should be changed. >>> >> >> Honestly, this is fair, and I understand your concerns behind it. I >> think my real issue is that there is no simple way to override one >> EXPERT setting without having to set them all. It would be nice if >> expert were a "visible if" menu, setting defaults if not selected, >> which allows direct override with a config file. Perhaps I will try to >> fix this in kbuild. >> > > So it turns out that untangling this in kbuild is very difficult > without getting very unexpected results. Given the audit and security > discussions around io_uring lately, I am inclined to believe the > proper action is still to remove 'if EXPERT'. I'm still going to disagree with that. In terms of security, io_uring is in a much better spot than it was in the past. Arguably it should have been easier to turn off when it went in, but that ship has sailed a long time ago and the need now isn't really there imho. The lack of audit isn't new and is something that'll be solved for the next release. -- Jens Axboe