From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 496F228024B for ; Fri, 23 Sep 2016 11:12:41 -0400 (EDT) Received: by mail-wm0-f71.google.com with SMTP id w84so20570977wmg.1 for ; Fri, 23 Sep 2016 08:12:41 -0700 (PDT) Received: from Galois.linutronix.de (Galois.linutronix.de. [2a01:7a0:2:106d:700::1]) by mx.google.com with ESMTPS id t129si3741466wme.25.2016.09.23.08.12.23 for (version=TLS1_2 cipher=AES128-SHA bits=128/128); Fri, 23 Sep 2016 08:12:23 -0700 (PDT) Date: Fri, 23 Sep 2016 17:08:04 +0200 (CEST) From: Thomas Gleixner Subject: acpi: Fix broken error check in map_processor() Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Dou Liyang Cc: cl@linux.com, tj@kernel.org, mika.j.penttila@gmail.com, mingo@redhat.com, akpm@linux-foundation.org, rjw@rjwysocki.net, hpa@zytor.com, yasu.isimatu@gmail.com, isimatu.yasuaki@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, gongzhaogang@inspur.com, len.brown@intel.com, lenb@kernel.org, chen.tang@easystack.cn, rafael@kernel.org, x86@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Gu Zheng , Tang Chen , Zhu Guihua map_processor() checks the cpuid value returned by acpi_map_cpuid() for -1 but acpi_map_cpuid() returns -EINVAL in case of error. As a consequence the error is ignored and the following access into percpu data with that negative cpuid results in a boot crash. This happens always when NR_CPUS/nr_cpu_ids is smaller than the number of processors listed in the ACPI tables. Use a proper error check for id < 0 so the function returns instead of trying to map CPU#(-EINVAL). Reported-by: Ingo Molnar Fixes: dc6db24d2476 ("x86/acpi: Set persistent cpuid <-> nodeid mapping when booting") Signed-off-by: Thomas Gleixner --- drivers/acpi/processor_core.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -284,7 +284,7 @@ EXPORT_SYMBOL_GPL(acpi_get_cpuid); static bool __init map_processor(acpi_handle handle, phys_cpuid_t *phys_id, int *cpuid) { - int type; + int type, id; u32 acpi_id; acpi_status status; acpi_object_type acpi_type; @@ -320,10 +320,11 @@ map_processor(acpi_handle handle, phys_c type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0; *phys_id = __acpi_get_phys_id(handle, type, acpi_id, false); - *cpuid = acpi_map_cpuid(*phys_id, acpi_id); - if (*cpuid == -1) - return false; + id = acpi_map_cpuid(*phys_id, acpi_id); + if (id < 0) + return false; + *cpuid = id; return true; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org