From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933576AbcI3PPo (ORCPT ); Fri, 30 Sep 2016 11:15:44 -0400 Received: from mail.skyhub.de ([78.46.96.112]:36474 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932237AbcI3PPh (ORCPT ); Fri, 30 Sep 2016 11:15:37 -0400 Date: Fri, 30 Sep 2016 17:15:38 +0200 From: Borislav Petkov To: Andy Lutomirski Cc: linux-tip-commits@vger.kernel.org, david@saggiorato.net, brgerst@gmail.com, peterz@infradead.org, dave@sr71.net, dvlasenk@redhat.com, mingo@kernel.org, jpoimboe@redhat.com, hpa@zytor.com, luto@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org Subject: Re: [tip:x86/urgent] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID Message-ID: <20160930151538.GA14423@nazgul.tnic> References: <8de723afbf0811071185039f9088733188b606c9.1475103911.git.luto@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 30, 2016 at 05:06:46AM -0700, tip-bot for Andy Lutomirski wrote: > Commit-ID: 05fb3c199bb09f5b85de56cc3ede194ac95c5e1f > Gitweb: http://git.kernel.org/tip/05fb3c199bb09f5b85de56cc3ede194ac95c5e1f > Author: Andy Lutomirski > AuthorDate: Wed, 28 Sep 2016 16:06:33 -0700 > Committer: Ingo Molnar > CommitDate: Fri, 30 Sep 2016 13:53:04 +0200 > > x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID > > Otherwise arch_task_struct_size == 0 and we die. While we're at it, > set X86_FEATURE_ALWAYS, too. ... > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 809eda0..bcc9ccc 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -804,21 +804,20 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) > identify_cpu_without_cpuid(c); > > /* cyrix could have cpuid enabled via c_identify()*/ > - if (!have_cpuid_p()) > - return; > + if (have_cpuid_p()) { Let's make it even simpler: --- From: Borislav Petkov Date: Fri, 30 Sep 2016 17:08:10 +0200 Subject: [PATCH] x86/boot: Streamline CPUID check conditional We have now: if (!have_cpuid_p()) ... if (have_cpuid_p()) ... Turn it into a good, ole if-else conditional which is much more readable. No functionality change. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/common.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9bd910a7dd0a..0a6fa6174ed8 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -800,9 +800,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) memset(&c->x86_capability, 0, sizeof c->x86_capability); c->extended_cpuid_level = 0; - if (!have_cpuid_p()) - identify_cpu_without_cpuid(c); - /* cyrix could have cpuid enabled via c_identify()*/ if (have_cpuid_p()) { cpu_detect(c); @@ -817,6 +814,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) if (this_cpu->c_bsp_init) this_cpu->c_bsp_init(c); + } else { + identify_cpu_without_cpuid(c); } setup_force_cpu_cap(X86_FEATURE_ALWAYS); -- 2.8.4 -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --