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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 549CDC43463 for ; Sun, 20 Sep 2020 15:55:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0503720773 for ; Sun, 20 Sep 2020 15:55:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="j4uRAT2E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726315AbgITPzp (ORCPT ); Sun, 20 Sep 2020 11:55:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726267AbgITPzp (ORCPT ); Sun, 20 Sep 2020 11:55:45 -0400 Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA728C061755; Sun, 20 Sep 2020 08:55:44 -0700 (PDT) Received: by mail-qk1-x742.google.com with SMTP id 16so12427329qkf.4; Sun, 20 Sep 2020 08:55:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:cc:in-reply-to:to; bh=wK83tl6Aps7O/Nyle+fjor+3BT0ZPHQ73i72gH6haeo=; b=j4uRAT2E8fdr2YaqrsiSPOPm8SjiSJMcVFWHVJQhudY7AjMagOuTaPaUrJZNB/DBxT RsSoXPsH0OZD1fdr6pAc+sedSbMtOJwM9dBbGX8EN9WBkRUekzOQnQi4yezBjIKvjoxp 4pTmIYXjTwfM8Ld7eN31Snn3HDl+xaBbxHqYulOMGjuIpzvi82ZxqqNXiPf1uBPbl0mW R3NIOxISkFL7B3tRSyYt+xnjnX4aUHUa0CKdIWEe71XW1d+175gN1d4Ezj+1k468etjw /p5aXBL9ieWXzE65cwKlIMBtQsaHBRTVaj0KGV3HN1O35ptGSjHCYh1Za9qlu8Ia58/F 0ILw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:cc:in-reply-to:to; bh=wK83tl6Aps7O/Nyle+fjor+3BT0ZPHQ73i72gH6haeo=; b=MVEvg7GVE0UwEB/ZAZ6gif/de22ie6uJH02CpMntE3eCjMiLc4mtOVY35v/lCpmGI1 do5epLnA0IOlZBcyYJpJHy+yAE8B81RoKiT9KIGTWhoAxJlwGBtfxriBrAhPIN4/Z+dT lYvjOZGNloV1B9R88+E8aovv9+C0tXS2KAzlzsu3JfAoYVTi1qGiwO56odm9U3yH9zOl v4mAHouV/IVfNaPp8CP2slwszyXAgV/E53rz/xQfbxx07tnK3mONhiXFmK6QA5GW3Jk5 vzfvcTK3oF5O/ozhCfkXIZpf7cEQU6BkLSBjkFcZx1zpDKXuSwY5oCkOnw/E+cXcsY6a HPjw== X-Gm-Message-State: AOAM53079/7R18hIx/eWVGFWm1GSrmbGEBNsXKkfLXBXONkxCpNv9qkt qlqM8bYTN9eBcVOFs/2dhI3mekHPJDjjcD++ X-Google-Smtp-Source: ABdhPJy0BhskiTDfvD8MBwip85dcX1wIsXPWtdth0juyqPe/DUqb3tBX97TvqdwX16zuipDqY5+Gyg== X-Received: by 2002:a05:620a:c10:: with SMTP id l16mr40194491qki.245.1600617343577; Sun, 20 Sep 2020 08:55:43 -0700 (PDT) Received: from localhost.localdomain ([65.140.37.34]) by smtp.gmail.com with ESMTPSA id v30sm7605819qtj.52.2020.09.20.08.55.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 20 Sep 2020 08:55:42 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: William Kucharski Mime-Version: 1.0 (1.0) Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Date: Sun, 20 Sep 2020 09:55:40 -0600 Message-Id: <76A432F3-4532-42A4-900E-16C0AC2D21D8@gmail.com> References: <20200920151510.GS32101@casper.infradead.org> Cc: Christoph Hellwig , Alexander Viro , Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org In-Reply-To: <20200920151510.GS32101@casper.infradead.org> To: Matthew Wilcox X-Mailer: iPhone Mail (18B5052h) Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org I really like that as it=E2=80=99s self-documenting and anyone debugging it c= an see what is actually being used at a glance. > On Sep 20, 2020, at 09:15, Matthew Wilcox wrote: >=20 > =EF=BB=BFOn Fri, Sep 18, 2020 at 02:45:25PM +0200, Christoph Hellwig wrote= : >> Add a flag to force processing a syscall as a compat syscall. This is >> required so that in_compat_syscall() works for I/O submitted by io_uring >> helper threads on behalf of compat syscalls. >=20 > Al doesn't like this much, but my suggestion is to introduce two new > opcodes -- IORING_OP_READV32 and IORING_OP_WRITEV32. The compat code > can translate IORING_OP_READV to IORING_OP_READV32 and then the core > code can know what that user pointer is pointing to.