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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 69C1EECE560 for ; Sat, 22 Sep 2018 00:24:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B91B20870 for ; Sat, 22 Sep 2018 00:24:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B91B20870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392450AbeIVGQK (ORCPT ); Sat, 22 Sep 2018 02:16:10 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44119 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391847AbeIVGKo (ORCPT ); Sat, 22 Sep 2018 02:10:44 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1g3Vds-0008BN-9h; Sat, 22 Sep 2018 01:19:24 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1g3Vdn-0000pj-3e; Sat, 22 Sep 2018 01:19:19 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Ingo Molnar" , "Linus Torvalds" , "Borislav Petkov" , "Thomas Gleixner" , "Fenghua Yu" , "Oleg Nesterov" , "Peter Zijlstra" , "H. Peter Anvin" , "Andy Lutomirski" , "Dave Hansen" Date: Sat, 22 Sep 2018 01:15:42 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 01/63] x86/fpu: Fix the 'nofxsr' boot parameter to also clear X86_FEATURE_FXSR_OPT In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.58-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ingo Molnar commit d364a7656c1855c940dfa4baf4ebcc3c6a9e6fd2 upstream. I tried to simulate an ancient CPU via this option, and found that it still has fxsr_opt enabled, confusing the FPU code. Make the 'nofxsr' option also clear FXSR_OPT flag. Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings --- arch/x86/kernel/cpu/common.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -199,6 +199,15 @@ static int __init x86_noinvpcid_setup(ch } early_param("noinvpcid", x86_noinvpcid_setup); +static int __init x86_fxsr_setup(char *s) +{ + setup_clear_cpu_cap(X86_FEATURE_FXSR); + setup_clear_cpu_cap(X86_FEATURE_FXSR_OPT); + setup_clear_cpu_cap(X86_FEATURE_XMM); + return 1; +} +__setup("nofxsr", x86_fxsr_setup); + #ifdef CONFIG_X86_32 static int cachesize_override = -1; static int disable_x86_serial_nr = 1; @@ -210,14 +219,6 @@ static int __init cachesize_setup(char * } __setup("cachesize=", cachesize_setup); -static int __init x86_fxsr_setup(char *s) -{ - setup_clear_cpu_cap(X86_FEATURE_FXSR); - setup_clear_cpu_cap(X86_FEATURE_XMM); - return 1; -} -__setup("nofxsr", x86_fxsr_setup); - static int __init x86_sep_setup(char *s) { setup_clear_cpu_cap(X86_FEATURE_SEP);