From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932381AbdBNSOV (ORCPT ); Tue, 14 Feb 2017 13:14:21 -0500 Received: from terminus.zytor.com ([65.50.211.136]:52430 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932248AbdBNSOP (ORCPT ); Tue, 14 Feb 2017 13:14:15 -0500 Subject: Re: [PATCH 3/6] x86/cpu: proc - remove "wp" status line in cpuinfo To: Mathias Krause , Thomas Gleixner , Ingo Molnar References: <1486933932-585-1-git-send-email-minipli@googlemail.com> <1486933932-585-4-git-send-email-minipli@googlemail.com> Cc: Andrew Morton , Borislav Petkov , "David S. Miller" , Jesper Nilsson , Mikael Starvik , Geert Uytterhoeven , x86@kernel.org, linux-kernel@vger.kernel.org, "H. Peter Anvin" From: "H. Peter Anvin" Message-ID: <3bd5980f-19fc-9eb4-477c-4786580ceafb@zytor.com> Date: Tue, 14 Feb 2017 10:13:22 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1486933932-585-4-git-send-email-minipli@googlemail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/12/17 13:12, Mathias Krause wrote: > As of commit a5c2a893dbd4 ("x86, 386 removal: Remove > CONFIG_X86_WP_WORKS_OK") the kernel won't boot if CR0.WP isn't working > correctly. This makes a process reading this file always see "wp : yes" > here -- otherwise there would be no process to begin with ;) > > As this status line in /proc/cpuinfo serves no purpose for quite some > time now, get rid of it. > > Cc: Borislav Petkov > Cc: H. Peter Anvin > Signed-off-by: Mathias Krause > --- > arch/x86/kernel/cpu/proc.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c > index 6df621ae62a7..c6c5217a7980 100644 > --- a/arch/x86/kernel/cpu/proc.c > +++ b/arch/x86/kernel/cpu/proc.c > @@ -30,8 +30,7 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c) > "coma_bug\t: %s\n" > "fpu\t\t: %s\n" > "fpu_exception\t: %s\n" > - "cpuid level\t: %d\n" > - "wp\t\t: yes\n", > + "cpuid level\t: %d\n", > static_cpu_has_bug(X86_BUG_FDIV) ? "yes" : "no", > static_cpu_has_bug(X86_BUG_F00F) ? "yes" : "no", > static_cpu_has_bug(X86_BUG_COMA) ? "yes" : "no", > @@ -45,8 +44,7 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c) > seq_printf(m, > "fpu\t\t: yes\n" > "fpu_exception\t: yes\n" > - "cpuid level\t: %d\n" > - "wp\t\t: yes\n", > + "cpuid level\t: %d\n", > c->cpuid_level); > } > #endif > Potential userspace breakage, which is why the line was left in the first place despite its value now being hard-coded. Removing it will save a whopping 9 bytes of kernel rodata; this is a very small price to pay for guaranteeing continued compatibility. Nacked-by: H. Peter Anvin