From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933123AbbESPoF (ORCPT ); Tue, 19 May 2015 11:44:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42749 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932581AbbESPoD (ORCPT ); Tue, 19 May 2015 11:44:03 -0400 From: Prarit Bhargava To: linux-kernel@vger.kernel.org Cc: Prarit Bhargava , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Andy Lutomirski , Borislav Petkov , Denys Vlasenko , Dave Hansen , Igor Mammedov , Fenghua Yu , Brian Gerst Subject: [PATCH] x86, cpuinfo x86_model_id whitespace cleanup Date: Tue, 19 May 2015 11:43:30 -0400 Message-Id: <1432050210-32036-1-git-send-email-prarit@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When comparing 'model name' fields in /proc/cpuinfo it was noticed that a simple test comparing the model name fields was failing. After some quick investigation it was noticed that the model name fields were actually different -- processor 0's model name field had trailing white space removed, while the other processors did not. Another way of seeing this behaviour is to convert spaces into underscores in the output of /proc/cpuinfo, [thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g' ______1_model_name :_AMD_Opteron(TM)_Processor_6272 _____63_model_name :_AMD_Opteron(TM)_Processor_6272_________________ which shows two different model name fields even though they should be the same. This occurs because the kernel calls strim() on cpu 0's x86_model_id field to output a pretty message to the console in print_cpu_info(), and as a result truncates the whitespace at the end of the x86_model_id field. The x86_model_id field should be the same for the same processors. This patch uses string functions to remove both leading and trailing whitespace in the x86_model_id field. As a result the print_cpu_info() output looks like smpboot: CPU0: AMD Opteron(TM) Processor 6272 (fam: 15, model: 01, stepping: 02) and the x86_model_id field is correct on all processors on AMD platforms [thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g' _____64_model_name :_AMD_Opteron(TM)_Processor_6272 and the functionality is correct on an Intel box: [thetango@prarit2]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g' ____144_model_name :_Intel(R)_Xeon(R)_CPU_E7-8890_v3_@_2.50GHz Signed-off-by: Prarit Bhargava Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: Dave Hansen Cc: Igor Mammedov Cc: Fenghua Yu Cc: Brian Gerst --- arch/x86/kernel/cpu/common.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a62cf04..9405c1e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -419,7 +419,6 @@ static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {}; static void get_model_name(struct cpuinfo_x86 *c) { unsigned int *v; - char *p, *q; if (c->extended_cpuid_level < 0x80000004) return; @@ -431,18 +430,10 @@ static void get_model_name(struct cpuinfo_x86 *c) c->x86_model_id[48] = 0; /* - * Intel chips right-justify this string for some dumb reason; - * undo that brain damage: + * Remove leading whitespace on Intel processors and trailing + * whitespace on AMD processors. */ - p = q = &c->x86_model_id[0]; - while (*p == ' ') - p++; - if (p != q) { - while (*p) - *q++ = *p++; - while (q <= &c->x86_model_id[48]) - *q++ = '\0'; /* Zero-pad the rest */ - } + strlcpy(c->x86_model_id, strim(c->x86_model_id), 48); } void cpu_detect_cache_sizes(struct cpuinfo_x86 *c) @@ -1122,7 +1113,7 @@ void print_cpu_info(struct cpuinfo_x86 *c) printk(KERN_CONT "%s ", vendor); if (c->x86_model_id[0]) - printk(KERN_CONT "%s", strim(c->x86_model_id)); + printk(KERN_CONT "%s", c->x86_model_id); else printk(KERN_CONT "%d86", c->x86); -- 1.7.9.3