From 2d55951368faa32ff098398c56780ebb6405a3d9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 12 Feb 2011 01:39:15 +0100 Subject: [PATCH] ACPI / ACPICA: Avoid crashing if _PRW is defined for the root object 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. The problem was introduced by commit bba63a296ffab20e08d9e8252d2f0d99 (ACPICA: Implicit notify support) that added the wake_device argument to acpi_setup_gpe_for_wake(). Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpica/evxfgpe.c | 51 ++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 24 deletions(-) diff --git a/drivers/acpi/acpica/evxfgpe.c b/drivers/acpi/acpica/evxfgpe.c index e9562a7cb2f9..3b20a3401b64 100644 --- a/drivers/acpi/acpica/evxfgpe.c +++ b/drivers/acpi/acpica/evxfgpe.c @@ -212,37 +212,40 @@ acpi_setup_gpe_for_wake(acpi_handle wake_device, 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; - } - - gpe_event_info->flags |= ACPI_GPE_CAN_WAKE; - status = AE_OK; + if (!gpe_event_info) { + goto unlock_and_exit; } + /* + * 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); }