From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753915Ab1A0W4X (ORCPT ); Thu, 27 Jan 2011 17:56:23 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:45900 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751373Ab1A0W4V (ORCPT ); Thu, 27 Jan 2011 17:56:21 -0500 From: "Rafael J. Wysocki" To: Len Brown Subject: [PATCH] ACPI / ACPICA: Avoid crashing if _PRW is defined for the root object Date: Thu, 27 Jan 2011 23:55:46 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.38-rc2+; KDE/4.4.4; x86_64; ; ) Cc: LKML , ACPI Devel Maling List , "Lin, Ming M" , "Moore, Robert" , Matthew Garrett MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201101272355.46737.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Some ACPI BIOSes define _PRW for the root object which causes acpi_setup_gpe_for_wake() to crash when trying to dereference the bogus device_node pointer. Avoid the crash by checking if wake_device is not the root object before attempting to set up the "implicit notify" mechanism for it. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpica/evxfgpe.c | 49 ++++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 23 deletions(-) Index: linux-2.6/drivers/acpi/acpica/evxfgpe.c =================================================================== --- linux-2.6.orig/drivers/acpi/acpica/evxfgpe.c +++ linux-2.6/drivers/acpi/acpica/evxfgpe.c @@ -212,37 +212,40 @@ acpi_setup_gpe_for_wake(acpi_handle wake return_ACPI_STATUS(AE_BAD_PARAMETER); } - /* Validate wake_device is of type Device */ - - device_node = ACPI_CAST_PTR(struct acpi_namespace_node, wake_device); - if (device_node->type != ACPI_TYPE_DEVICE) { - return_ACPI_STATUS(AE_BAD_PARAMETER); - } - flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock); /* Ensure that we have a valid GPE number */ gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number); - if (gpe_event_info) { - /* - * If there is no method or handler for this GPE, then the - * wake_device will be notified whenever this GPE fires (aka - * "implicit notify") Note: The GPE is assumed to be - * level-triggered (for windows compatibility). - */ - if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) == - ACPI_GPE_DISPATCH_NONE) { - gpe_event_info->flags = - (ACPI_GPE_DISPATCH_NOTIFY | - ACPI_GPE_LEVEL_TRIGGERED); - gpe_event_info->dispatch.device_node = device_node; - } + if (!gpe_event_info) { + goto unlock_and_exit; + } - gpe_event_info->flags |= ACPI_GPE_CAN_WAKE; - status = AE_OK; + /* + * If there is no method or handler for this GPE, then the + * wake_device will be notified whenever this GPE fires (aka + * "implicit notify") Note: The GPE is assumed to be + * level-triggered (for windows compatibility). + */ + if (((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) == + ACPI_GPE_DISPATCH_NONE) && (wake_device != ACPI_ROOT_OBJECT)) { + + /* Validate wake_device is of type Device */ + + device_node = ACPI_CAST_PTR(struct acpi_namespace_node, + wake_device); + if (device_node->type != ACPI_TYPE_DEVICE) { + goto unlock_and_exit; + } + gpe_event_info->flags = (ACPI_GPE_DISPATCH_NOTIFY | + ACPI_GPE_LEVEL_TRIGGERED); + gpe_event_info->dispatch.device_node = device_node; } + gpe_event_info->flags |= ACPI_GPE_CAN_WAKE; + status = AE_OK; + + unlock_and_exit: acpi_os_release_lock(acpi_gbl_gpe_lock, flags); return_ACPI_STATUS(status); }