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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 15ABBC2BA17 for ; Mon, 6 Apr 2020 18:27:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9DE52072F for ; Mon, 6 Apr 2020 18:27:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726197AbgDFS1O (ORCPT ); Mon, 6 Apr 2020 14:27:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:42392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725876AbgDFS1O (ORCPT ); Mon, 6 Apr 2020 14:27:14 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B902E206C3; Mon, 6 Apr 2020 18:27:12 +0000 (UTC) Date: Mon, 6 Apr 2020 14:27:11 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: Christoph Hellwig , Thomas Gleixner , LKML , x86@kernel.org, "Kenneth R. Crudup" , Paolo Bonzini , Jessica Yu , Fenghua Yu , Xiaoyao Li , Nadav Amit , Thomas Hellstrom , Sean Christopherson , Tony Luck Subject: Re: [patch 1/2] x86,module: Detect VMX modules and disable Split-Lock-Detect Message-ID: <20200406142711.47780ff5@gandalf.local.home> In-Reply-To: <20200406152231.GQ20730@hirez.programming.kicks-ass.net> References: <20200402123258.895628824@linutronix.de> <20200402124205.242674296@linutronix.de> <20200406122343.GA10683@infradead.org> <20200406144020.GP20730@hirez.programming.kicks-ass.net> <20200406151847.GA25147@infradead.org> <20200406152231.GQ20730@hirez.programming.kicks-ass.net> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 6 Apr 2020 17:22:31 +0200 Peter Zijlstra wrote: > On Mon, Apr 06, 2020 at 08:18:47AM -0700, Christoph Hellwig wrote: > > On Mon, Apr 06, 2020 at 04:40:20PM +0200, Peter Zijlstra wrote: > > > It is absolutely bonkers, but at the same time we can extend this > > > infrastructure to scan for dubious code patterns we don't want to > > > support. Like for instance direct manipulation of CR4. > > > > But that is not what this code does - it disables split lock detection. > > If it failed to load the module the whole thing would make a little > > more sense. > > If this lives, it'll be to just to fail module loading. IIRC the same > was suggested elsewhere in the thread. I believe I may have been the one to suggest it. It's no different than breaking kabi if you ask me. If a module can't deal with a new feature, than it should not be able to load. And let whoever owns that module fix it for their users. -- Steve