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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A3C50C2D0EC for ; Tue, 7 Apr 2020 18:55:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63C6B20730 for ; Tue, 7 Apr 2020 18:55:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="WMOAgM9D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726796AbgDGSz3 (ORCPT ); Tue, 7 Apr 2020 14:55:29 -0400 Received: from mail-il1-f196.google.com ([209.85.166.196]:42789 "EHLO mail-il1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726339AbgDGSz3 (ORCPT ); Tue, 7 Apr 2020 14:55:29 -0400 Received: by mail-il1-f196.google.com with SMTP id f16so4283006ilj.9 for ; Tue, 07 Apr 2020 11:55:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=/tslLXuxoyVjSOLI35ip3I2Cd88F7bzLCM3Xyu1bIgM=; b=WMOAgM9DrLI4UXG0tvW08mYqzl77Gk7Xb0oSU1n8sL1ius69d9XwTvx0OUV8qBYAqL SvUPKPH6SQ6mY9EXYJuX2zhxE9TOJ46+yakaNtEpBkwaxKsape35cHBAeLeS6z68+9mw TcPIsxqO9PEpOkEzb2/Ji/WtxrG93oiM9mpk5mmNxq8AHl0Kn7hQE7npRo8Q4o2zTdAn LHhh0XIZCRmBp2qtirzd99BwrSeFd8ZI9q+ID5u1gvnkjiUumiCIh42HS12eXoE+7NJU CB9hrzTlr1cHWYR2lHSSMIQOYhtoIazsjcDEIaX7/PseveInY1o3oWdd10ZaSakarfuq Hz1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=/tslLXuxoyVjSOLI35ip3I2Cd88F7bzLCM3Xyu1bIgM=; b=f1k8pkNvI/pdatnVZNPmHWxvFXH2UqdlAqR3RMepguNBqZQtyw8K33X2yDbQewE4+Z 1P498jYPLXyFGRAnfuhRw0eLwZGkfpwvVf/2y2FY5CZk/l9rt1xo9ZZU7ZmqERY0y/Pd madc3ewqo920EVdsCQskyCRRlthJ0B7l4xLWC5Cl7lQ6IQi8uah4x1TXK5PbMylEeGr7 Nc4fzyeN54PLCyJ/YPWPyJk9HW6Kg8o39PIcX57ikfqqV/KL+6iej/OFLguXQAlaKkoS 9d61kt6hXA4dlPP5FtC17X9TQD61nSVLbeAbqme8UPivXvy6g0Q5IYeEOac5lWZ8+bOz R/AQ== X-Gm-Message-State: AGi0PuaprF7WN79eS2y6gXHrw2+xO6gqKbJEBGT7T3OJopfyYB1Su6AP eGS/EmdhrsCyjNYGRPFW1Nc= X-Google-Smtp-Source: APiQypKz3YCF7dQUKJtJtT0hWDaVgRVOTnWtQ71Ph3AWJXhZHfAJWm54lRtwbLGHWugt7DHibd/eVw== X-Received: by 2002:a92:1581:: with SMTP id 1mr3983101ilv.144.1586285727755; Tue, 07 Apr 2020 11:55:27 -0700 (PDT) Received: from ?IPv6:2601:647:4700:9b2:1d50:a6a4:b3be:b3e4? ([2601:647:4700:9b2:1d50:a6a4:b3be:b3e4]) by smtp.gmail.com with ESMTPSA id x10sm7509021ili.88.2020.04.07.11.55.25 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Apr 2020 11:55:26 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.80.23.2.2\)) Subject: Re: [PATCH 4/4] x86,module: Detect CRn and DRn manipulation From: Nadav Amit In-Reply-To: <20200407111007.429362016@infradead.org> Date: Tue, 7 Apr 2020 11:55:21 -0700 Cc: Thomas Gleixner , LKML , hch@infradead.org, Sean Christopherson , mingo , bp , hpa@zytor.com, x86 , "Kenneth R. Crudup" , Jessica Yu , Rasmus Villemoes , Paolo Bonzini , Fenghua Yu , Xiaoyao Li , Thomas Hellstrom , Tony Luck , Steven Rostedt , Greg Kroah-Hartman , jannh@google.com, keescook@chromium.org, David.Laight@aculab.com, Doug Covelli , mhiramat@kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <10ABBCEE-A74D-4100-99D9-05B4C1758FF6@gmail.com> References: <20200407110236.930134290@infradead.org> <20200407111007.429362016@infradead.org> To: Peter Zijlstra X-Mailer: Apple Mail (2.3608.80.23.2.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Apr 7, 2020, at 4:02 AM, Peter Zijlstra = wrote: >=20 > Since we now have infrastructure to analyze module text, disallow > modules that write to CRn and DRn registers. Assuming the kernel is built without CONFIG_PARAVIRT, what is the right = way for out-of-tree modules to write to CRs? Let=E2=80=99s say CR2?