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Commit ff102ea9 authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by Len Brown
Browse files

ACPI: video - remove unsafe uses of list_for_each_safe() 



list_for_each_safe() only protects list from list alterations
performed by the same thread. One still needs to implement
proper locking when list is being accessed from several threads.

Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
Acked-by: default avatarZhang Rui <rui.zhang@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent f51e8391

drivers/acpi/video.c

+34 −37
Original line number Diff line number Diff line
@@ -1462,12 +1462,14 @@ acpi_video_bus_get_one_device(struct acpi_device *device, 


static void acpi_video_device_rebind(struct acpi_video_bus *video)

{

	struct list_head *node, *next;

	list_for_each_safe(node, next, &video->video_device_list) {

		struct acpi_video_device *dev =

		    container_of(node, struct acpi_video_device, entry);

	struct acpi_video_device *dev;



	down(&video->sem);



	list_for_each_entry(dev, &video->video_device_list, entry)

		acpi_video_device_bind(video, dev);

	}



	up(&video->sem);

}



/*
@@ -1592,30 +1594,33 @@ static int acpi_video_device_enumerate(struct acpi_video_bus *video) 


static int acpi_video_switch_output(struct acpi_video_bus *video, int event)

{

	struct list_head *node, *next;

	struct list_head *node;

	struct acpi_video_device *dev = NULL;

	struct acpi_video_device *dev_next = NULL;

	struct acpi_video_device *dev_prev = NULL;

	unsigned long state;

	int status = 0;



	down(&video->sem);



	list_for_each_safe(node, next, &video->video_device_list) {

	list_for_each(node, &video->video_device_list) {

		dev = container_of(node, struct acpi_video_device, entry);

		status = acpi_video_device_get_state(dev, &state);

		if (state & 0x2) {

			dev_next =

			    container_of(node->next, struct acpi_video_device,

					 entry);

			dev_prev =

			    container_of(node->prev, struct acpi_video_device,

					 entry);

			dev_next = container_of(node->next,

					struct acpi_video_device, entry);

			dev_prev = container_of(node->prev,

					struct acpi_video_device, entry);

			goto out;

		}

	}



	dev_next = container_of(node->next, struct acpi_video_device, entry);

	dev_prev = container_of(node->prev, struct acpi_video_device, entry);



 out:

	up(&video->sem);



	switch (event) {

	case ACPI_VIDEO_NOTIFY_CYCLE:

	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:
@@ -1691,24 +1696,17 @@ acpi_video_bus_get_devices(struct acpi_video_bus *video, 
			   struct acpi_device *device)

{

	int status = 0;

	struct list_head *node, *next;



	struct acpi_device *dev;



	acpi_video_device_enumerate(video);



	list_for_each_safe(node, next, &device->children) {

		struct acpi_device *dev =

		    list_entry(node, struct acpi_device, node);



		if (!dev)

			continue;

	list_for_each_entry(dev, &device->children, node) {



		status = acpi_video_bus_get_one_device(dev, video);

		if (ACPI_FAILURE(status)) {

			ACPI_EXCEPTION((AE_INFO, status, "Cant attach device"));

			continue;

		}



	}

	return status;

}
@@ -1724,9 +1722,6 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device) 


	video = device->video;



	down(&video->sem);

	list_del(&device->entry);

	up(&video->sem);

	acpi_video_device_remove_fs(device->dev);



	status = acpi_remove_notify_handler(device->dev->handle,
@@ -1734,31 +1729,33 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device) 
					    acpi_video_device_notify);

	backlight_device_unregister(device->backlight);

	video_output_unregister(device->output_dev);



	return 0;

}



static int acpi_video_bus_put_devices(struct acpi_video_bus *video)

{

	int status;

	struct list_head *node, *next;

	struct acpi_video_device *dev, *next;



	down(&video->sem);



	list_for_each_safe(node, next, &video->video_device_list) {

		struct acpi_video_device *data =

		    list_entry(node, struct acpi_video_device, entry);

		if (!data)

			continue;

	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {



		status = acpi_video_bus_put_one_device(data);

		status = acpi_video_bus_put_one_device(dev);

		if (ACPI_FAILURE(status))

			printk(KERN_WARNING PREFIX

			       "hhuuhhuu bug in acpi video driver.\n");



		if (data->brightness)

			kfree(data->brightness->levels);

		kfree(data->brightness);

		kfree(data);

		if (dev->brightness) {

			kfree(dev->brightness->levels);

			kfree(dev->brightness);

		}

		list_del(&dev->entry);

		kfree(dev);

	}



	up(&video->sem);



	return 0;

}