Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932120AbaD3FIk (ORCPT ); Wed, 30 Apr 2014 01:08:40 -0400 Received: from mga02.intel.com ([134.134.136.20]:63449 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751822AbaD3FIg (ORCPT ); Wed, 30 Apr 2014 01:08:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,956,1389772800"; d="scan'208";a="532199774" Message-ID: <53608551.8010208@linux.intel.com> Date: Wed, 30 Apr 2014 13:08:33 +0800 From: Jiang Liu Organization: Intel User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Lan Tianyu , rjw@rjwysocki.net, lenb@kernel.org, katoh@mikage.ne.jp, smf.linux@ntlworld.com CC: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ACPI/Processor: Fix failure of loading acpi-cpufreq driver References: <1398827428-25540-1-git-send-email-tianyu.lan@intel.com> In-Reply-To: <1398827428-25540-1-git-send-email-tianyu.lan@intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tianyu, With the suggested fix, we still need to protect acpi_processor_hotadd_init() when pr->apic_id is -1, otherwise it may cause invalid memory access. Best Regards! Gerry diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index c29c2c3ec0ad..e17befc54c34 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -170,6 +170,9 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) acpi_status status; int ret; + if (pr->apic_id < 0) + return -ENODEV; + status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) return -ENODEV; On 2014/4/30 11:10, Lan Tianyu wrote: > According commit d640113fe(ACPI: processor: fix acpi_get_cpuid for UP > processor), Bios may not provide _MAT or MADT tables and acpi_get_apicid() > always returns -1. For these cases, original code will pass apic_id with > vaule of -1 to acpi_map_cpuid() and it will check the acpi_id. If acpi_id > is equal to zero, ignores apic_id and return zero for CPU0. > > Commit b981513(ACPI / scan: bail out early if failed to parse APIC > ID for CPU) changed the behavior. Return ENODEV when find apic_id is > less than zero after calling acpi_get_apicid(). This causes acpi-cpufreq > driver fails to be loaded on some machines. This patch is to fix it. > > Reference:https://bugzilla.kernel.org/show_bug.cgi?id=73781 > Cc: stable@vger.kernel.org v3.14 > Reported-and-tested-by: KATO Hiroshi > Reported-and-tested-by: Stuart Foster > Signed-off-by: Lan Tianyu > --- > drivers/acpi/acpi_processor.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index c29c2c3..d55b603 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -260,10 +260,8 @@ static int acpi_processor_get_info(struct acpi_device *device) > } > > apic_id = acpi_get_apicid(pr->handle, device_declaration, pr->acpi_id); > - if (apic_id < 0) { > + if (apic_id < 0) > acpi_handle_debug(pr->handle, "failed to get CPU APIC ID.\n"); > - return -ENODEV; > - } > pr->apic_id = apic_id; > > cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/