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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham 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 80268C43219 for ; Wed, 1 May 2019 11:59:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54B9421743 for ; Wed, 1 May 2019 11:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726418AbfEAL7e (ORCPT ); Wed, 1 May 2019 07:59:34 -0400 Received: from bmailout1.hostsharing.net ([83.223.95.100]:55325 "EHLO bmailout1.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726083AbfEAL7d (ORCPT ); Wed, 1 May 2019 07:59:33 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 31CB530000F2A; Wed, 1 May 2019 13:59:31 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id EE4CF233EA5; Wed, 1 May 2019 13:59:30 +0200 (CEST) Date: Wed, 1 May 2019 13:59:30 +0200 From: Lukas Wunner To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sebastian Andrzej Siewior , Borislav Petkov , Rik van Riel , "H. Peter Anvin" , "Jason A. Donenfeld" , Andy Lutomirski , Ard Biesheuvel , Dave Hansen , Ingo Molnar , Nicolai Stange , Paolo Bonzini , Radim =?iso-8859-1?B?S3I/P23hPz8=?= , Thomas Gleixner , kvm ML , linux-efi , x86-ml Subject: Re: [PATCH 4.19 083/100] x86/fpu: Dont export __kernel_fpu_{begin,end}() Message-ID: <20190501115930.wa7ubea67rmsoqo7@wunner.de> References: <20190430113608.616903219@linuxfoundation.org> <20190430113612.682532449@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190430113612.682532449@linuxfoundation.org> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 30, 2019 at 01:38:52PM +0200, Greg Kroah-Hartman wrote: > commit 12209993e98c5fa1855c467f22a24e3d5b8be205 upstream. > > There is one user of __kernel_fpu_begin() and before invoking it, > it invokes preempt_disable(). So it could invoke kernel_fpu_begin() > right away. The 32bit version of arch_efi_call_virt_setup() and > arch_efi_call_virt_teardown() does this already. > > The comment above *kernel_fpu*() claims that before invoking > __kernel_fpu_begin() preemption should be disabled and that KVM is a > good example of doing it. Well, KVM doesn't do that since commit > > f775b13eedee2 ("x86,kvm: move qemu/guest FPU switching out to vcpu_run") > > so it is not an example anymore. > > With EFI gone as the last user of __kernel_fpu_{begin|end}(), both can > be made static and not exported anymore. This is just a cleanup and therefore doesn't seem to satisfy the rules for stable patches per Documentation/process/stable-kernel-rules.rst ("It must fix a real bug that bothers people / fix a problem that causes a build error"). Why is it being queued up for stable and why are the rules disregarded here? Thanks, Lukas