Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934874AbcJHFdn (ORCPT ); Sat, 8 Oct 2016 01:33:43 -0400 Received: from mail-ua0-f195.google.com ([209.85.217.195]:33878 "EHLO mail-ua0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965005AbcJHFdf (ORCPT ); Sat, 8 Oct 2016 01:33:35 -0400 MIME-Version: 1.0 In-Reply-To: References: From: Yinghai Lu Date: Fri, 7 Oct 2016 22:33:33 -0700 X-Google-Sender-Auth: JoGKx4D458XSZAudKCAZJUYYn78 Message-ID: Subject: Re: [tip:x86/urgent] x86/acpi: Prevent LAPIC id 0xff from being accounted To: Tang Chen , Ingo Molnar , "H. Peter Anvin" , Tony Luck , Thomas Gleixner , Linux Kernel Mailing List , "Rafael J. Wysocki" , Len Brown , Yinghai Lu Cc: "linux-tip-commits@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1106 Lines: 36 On Fri, Oct 7, 2016 at 10:26 PM, Yinghai Lu wrote: > On Fri, Oct 7, 2016 at 6:28 AM, tip-bot for Thomas Gleixner >> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c >> index 32a7d70..6d35baf 100644 >> --- a/arch/x86/kernel/acpi/boot.c >> +++ b/arch/x86/kernel/acpi/boot.c >> @@ -233,6 +233,9 @@ acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end) >> >> acpi_table_print_madt_entry(header); >> >> + if (processor->id >= 0xff) >> + return -EINVAL; >> + >> /* >> * We need to register disabled CPU as well to permit >> * counting disabled CPUs. This allows us to size > > > some thing is wrong: > > [ 71.787437] ACPI: LAPIC (acpi_id[0xff] lapic_id[0xff] disabled) > [ 71.799681] ACPI: Error parsing LAPIC/X2APIC entries > [ 71.809934] ACPI: Invalid BIOS MADT, disabling ACPI > > looks like should change > return -EINVAL ; > ==> > return 0; also processor->id is u8, so the patch should be: >> + if (processor->id == 0xff) >> + return -EINVAL; >> +