From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751803AbdAYLnn (ORCPT ); Wed, 25 Jan 2017 06:43:43 -0500 Received: from terminus.zytor.com ([65.50.211.136]:49214 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751414AbdAYLnl (ORCPT ); Wed, 25 Jan 2017 06:43:41 -0500 Date: Wed, 25 Jan 2017 03:41:26 -0800 From: tip-bot for Andy Lutomirski Message-ID: Cc: tglx@linutronix.de, luto@kernel.org, gnomes@lxorguk.ukuu.org.uk, bp@alien8.de, fenghua.yu@intel.com, hpa@zytor.com, dave.hansen@linux.intel.com, torvalds@linux-foundation.org, oleg@redhat.com, linux-kernel@vger.kernel.org, tedheadster@gmail.com, mingo@kernel.org, bp@suse.de, yu-cheng.yu@intel.com, peterz@infradead.org, brgerst@gmail.com, riel@redhat.com Reply-To: brgerst@gmail.com, bp@suse.de, yu-cheng.yu@intel.com, peterz@infradead.org, riel@redhat.com, tglx@linutronix.de, luto@kernel.org, dave.hansen@linux.intel.com, torvalds@linux-foundation.org, hpa@zytor.com, oleg@redhat.com, tedheadster@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, gnomes@lxorguk.ukuu.org.uk, bp@alien8.de, fenghua.yu@intel.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/fpu] x86/cpu: Re-apply forced caps every time CPU caps are re-read Git-Commit-ID: 60d3450167433f2d099ce2869dc52dd9e7dc9b29 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 60d3450167433f2d099ce2869dc52dd9e7dc9b29 Gitweb: http://git.kernel.org/tip/60d3450167433f2d099ce2869dc52dd9e7dc9b29 Author: Andy Lutomirski AuthorDate: Wed, 18 Jan 2017 11:15:39 -0800 Committer: Ingo Molnar CommitDate: Wed, 25 Jan 2017 10:12:41 +0100 x86/cpu: Re-apply forced caps every time CPU caps are re-read Calling get_cpu_cap() will reset a bunch of CPU features. This will cause the system to lose track of force-set and force-cleared features in the words that are reset until the end of CPU initialization. This can cause X86_FEATURE_FPU, for example, to change back and forth during boot and potentially confuse CPU setup. To minimize the chance of confusion, re-apply forced caps every time get_cpu_cap() is called. Signed-off-by: Andy Lutomirski Reviewed-by: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Matthew Whitehead Cc: Oleg Nesterov Cc: One Thousand Gnomes Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Yu-cheng Yu Link: http://lkml.kernel.org/r/c817eb373d2c67c2c81413a70fc9b845fa34a37e.1484705016.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/common.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 2ea16e0..d09b5ee 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -758,6 +758,13 @@ void get_cpu_cap(struct cpuinfo_x86 *c) c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a); init_scattered_cpuid_features(c); + + /* + * Clear/Set all flags overridden by options, after probe. + * This needs to happen each time we re-probe, which may happen + * several times during CPU initialization. + */ + apply_forced_caps(c); } static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)