Commit 3ea7f59a authored by Armin Wolf's avatar Armin Wolf Committed by Hans de Goede
Browse files

platform/x86: wmi: Decouple legacy WMI notify handlers from wmi_block_list 



Until now, legacy WMI notify handler functions where using the
wmi_block_list, which did no refcounting on the returned WMI device.
This meant that the WMI device could disappear at any moment,
potentially leading to various errors.
Fix this by using bus_find_device() which returns an actual
reference to the found WMI device.

Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.

Signed-off-by: default avatarArmin Wolf <W_Armin@gmx.de>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240103192707.115512-4-W_Armin@gmx.de


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 3d8a29fe

drivers/platform/x86/wmi.c

+68 −50
Original line number Diff line number Diff line
@@ -219,6 +219,17 @@ static int wmidev_match_guid(struct device *dev, const void *data) 
	return 0;

}



static int wmidev_match_notify_id(struct device *dev, const void *data)

{

	struct wmi_block *wblock = dev_to_wblock(dev);

	const u32 *notify_id = data;



	if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)

		return 1;



	return 0;

}



static struct bus_type wmi_bus_type;



static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
@@ -238,6 +249,17 @@ static struct wmi_device *wmi_find_device_by_guid(const char *guid_string) 
	return dev_to_wdev(dev);

}



static struct wmi_device *wmi_find_event_by_notify_id(const u32 notify_id)

{

	struct device *dev;



	dev = bus_find_device(&wmi_bus_type, NULL, &notify_id, wmidev_match_notify_id);

	if (!dev)

		return ERR_PTR(-ENODEV);



	return to_wmi_device(dev);

}



static void wmi_device_put(struct wmi_device *wdev)

{

	put_device(&wdev->dev);
@@ -572,34 +594,30 @@ acpi_status wmi_install_notify_handler(const char *guid, 
				       wmi_notify_handler handler,

				       void *data)

{

	struct wmi_block *block;

	guid_t guid_input;



	if (!guid || !handler)

		return AE_BAD_PARAMETER;



	if (guid_parse(guid, &guid_input))

		return AE_BAD_PARAMETER;



	list_for_each_entry(block, &wmi_block_list, list) {

		acpi_status wmi_status;

	struct wmi_block *wblock;

	struct wmi_device *wdev;

	acpi_status status;



		if (guid_equal(&block->gblock.guid, &guid_input)) {

			if (block->handler)

				return AE_ALREADY_ACQUIRED;

	wdev = wmi_find_device_by_guid(guid);

	if (IS_ERR(wdev))

		return AE_ERROR;



			block->handler = handler;

			block->handler_data = data;

	wblock = container_of(wdev, struct wmi_block, dev);

	if (wblock->handler) {

		status = AE_ALREADY_ACQUIRED;

	} else {

		wblock->handler = handler;

		wblock->handler_data = data;



			wmi_status = wmi_method_enable(block, true);

			if (ACPI_FAILURE(wmi_status))

				dev_warn(&block->dev.dev, "Failed to enable device\n");

		if (ACPI_FAILURE(wmi_method_enable(wblock, true)))

			dev_warn(&wblock->dev.dev, "Failed to enable device\n");



			return AE_OK;

		}

		status = AE_OK;

	}



	return AE_NOT_EXIST;

	wmi_device_put(wdev);



	return status;

}

EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
@@ -613,34 +631,30 @@ EXPORT_SYMBOL_GPL(wmi_install_notify_handler); 
 */

acpi_status wmi_remove_notify_handler(const char *guid)

{

	struct wmi_block *block;

	guid_t guid_input;



	if (!guid)

		return AE_BAD_PARAMETER;



	if (guid_parse(guid, &guid_input))

		return AE_BAD_PARAMETER;



	list_for_each_entry(block, &wmi_block_list, list) {

		acpi_status wmi_status;

	struct wmi_block *wblock;

	struct wmi_device *wdev;

	acpi_status status;



		if (guid_equal(&block->gblock.guid, &guid_input)) {

			if (!block->handler)

				return AE_NULL_ENTRY;

	wdev = wmi_find_device_by_guid(guid);

	if (IS_ERR(wdev))

		return AE_ERROR;



			wmi_status = wmi_method_enable(block, false);

			if (ACPI_FAILURE(wmi_status))

				dev_warn(&block->dev.dev, "Failed to disable device\n");

	wblock = container_of(wdev, struct wmi_block, dev);

	if (!wblock->handler) {

		status = AE_NULL_ENTRY;

	} else {

		if (ACPI_FAILURE(wmi_method_enable(wblock, false)))

			dev_warn(&wblock->dev.dev, "Failed to disable device\n");



			block->handler = NULL;

			block->handler_data = NULL;

		wblock->handler = NULL;

		wblock->handler_data = NULL;



			return AE_OK;

		}

		status = AE_OK;

	}



	return AE_NOT_EXIST;

	wmi_device_put(wdev);



	return status;

}

EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
@@ -657,15 +671,19 @@ EXPORT_SYMBOL_GPL(wmi_remove_notify_handler); 
acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)

{

	struct wmi_block *wblock;

	struct wmi_device *wdev;

	acpi_status status;



	list_for_each_entry(wblock, &wmi_block_list, list) {

		struct guid_block *gblock = &wblock->gblock;

	wdev = wmi_find_event_by_notify_id(event);

	if (IS_ERR(wdev))

		return AE_NOT_FOUND;



		if ((gblock->flags & ACPI_WMI_EVENT) && gblock->notify_id == event)

			return get_event_data(wblock, out);

	}

	wblock = container_of(wdev, struct wmi_block, dev);

	status = get_event_data(wblock, out);



	return AE_NOT_FOUND;

	wmi_device_put(wdev);



	return status;

}

EXPORT_SYMBOL_GPL(wmi_get_event_data);