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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,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 677E0C4CECC for ; Mon, 27 Apr 2020 20:13:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EF9D20728 for ; Mon, 27 Apr 2020 20:13:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="X30MjfD2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726688AbgD0UNX (ORCPT ); Mon, 27 Apr 2020 16:13:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726748AbgD0UNW (ORCPT ); Mon, 27 Apr 2020 16:13:22 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FFE7C03C1A7 for ; Mon, 27 Apr 2020 13:13:21 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id h12so247725pjz.1 for ; Mon, 27 Apr 2020 13:13:21 -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=pR3kteFnkwSeWnYo3zmPG42eO8gLN75E8zh/Lytmcss=; b=X30MjfD2pcrZdg/csE29+RnQMgN/Tx9Jq3MxwVazvhXHpvNw9wYewYDsApFQiK44/c KAmPujAsMO48SwgGs0B0kEkoT9xMwc1ijVSlwlq9k/QRjDJ9rdJ3tOboJfkhgj3RX8xs WWbz0lZip5fhM1yypLELtlV9xuZftAdzSWG7hDFg9ZEj6/ssvTfMnR6ptcVV9YSdyOc5 ZJG1n5fRV+gdPg4EiwYgYElYu10cZTUcYMx+dDuwojLKF8hol7cT2HNXVmCwq/bQ4q1w SngfvwupqaDeHnsQuuWIfnDCUz8WgSYK1/6K6yxtNnTxoAzop8iAjlYJn97xmd7uuIea vyug== 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=pR3kteFnkwSeWnYo3zmPG42eO8gLN75E8zh/Lytmcss=; b=b2Nd6iKOsIrKqLh5VrW/hHV7COglyTUNRaxk9bzOJQS6/b9NLQtOc+2ZoQmEYmpZ/E JEfIEzdz3gGvXy/4FVAwjiOV4iprOXdfuaf6gIVEac7VKBOrxN1VD3FnSM+tlNGlomCa QOW905m4ZlgHENNdqrYeZ1E9qhjE2t+lJOrh9wdvLCbbKzQmsJpUv+WKzSqIrV9PkR51 MgJH55YNDE2qV4Ka45xOuoMPO6BIkkSWEMUCLLenSfvp9jiME22g0aSyRwuIPaKKo9Pa vfHsmHvGBoM99j0I6UQe3ySaeFEdHLyooLMSB7pXzhU5ZTkDyM2w+Bgn5VyfW8w75o5o n06w== X-Gm-Message-State: AGi0PuYZtGnLRpiE3fx32KZ1pnDtSIA6QgP5vIPEzqmvud1rWlMV/wCp ytQTc882jW2qu1U8u8bxdas5bFiLyKd9tA== X-Google-Smtp-Source: APiQypKZwo4DH1PFNPp9oLk8VHPEhy4uATbvVBY6LPpPSmU+M/2Rc7zRonJad7UtQIOOLpJGBJ3hbQ== X-Received: by 2002:a17:902:c281:: with SMTP id i1mr25095107pld.327.1588018400353; Mon, 27 Apr 2020 13:13:20 -0700 (PDT) Received: from [192.168.1.188] ([66.219.217.145]) by smtp.gmail.com with ESMTPSA id a129sm13152689pfb.102.2020.04.27.13.13.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 27 Apr 2020 13:13:19 -0700 (PDT) Subject: Re: io_uring, IORING_OP_RECVMSG and ancillary data To: Christoph Hellwig Cc: Jann Horn , Andreas Smas , linux-fsdevel , io-uring References: <45d7558a-d0c8-4d3f-c63a-33fd2fb073a5@kernel.dk> <217dc782-161f-7aea-2d18-4e88526b8e1d@kernel.dk> <20200427201043.GA6292@infradead.org> From: Jens Axboe Message-ID: Date: Mon, 27 Apr 2020 14:13:18 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200427201043.GA6292@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 4/27/20 2:10 PM, Christoph Hellwig wrote: > On Mon, Apr 27, 2020 at 02:08:25PM -0600, Jens Axboe wrote: >> Possibly... Totally untested, maybe I forgot to mention that :-) >> I'll check. >> >> The question was more "in principle" if this was a viable approach. The >> whole cmsg_type and cmsg_level is really a mess. > > FYI, I have a series in the works to sort out the set_fs and > casting to/from __user mess around msg_control. It needs a little > more work, but hopefully I can find some time the next days. That'd be great - looking at it right now, I'd need to refactor ____sys_sendmsg (and ditto receive side) to poke at cmsg before allowing us to proceed. I'll wait for you to post your series and base it on top of that, if appropriate. -- Jens Axboe