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Commit 0cd75047 authored by Sergey Klyaus's avatar Sergey Klyaus Committed by Greg Kroah-Hartman
Browse files

driver core: fix race with userland in device_add() 



bus_add_device() should be called before devtmpfs_create_node(), so when
userland application opens device from devtmpfs, it wouldn't get ENODEV
from kernel, because device_add() wasn't completed.

Signed-off-by: default avatarSergey Klyaus <Sergey.Klyaus@Tune-IT.Ru>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4ef67a8c

drivers/base/core.c

+18 −20
Original line number Original line Diff line number Diff line
@@ -1019,18 +1019,6 @@ int device_add(struct device *dev) 
	if (error)

	if (error)

		goto attrError;

		goto attrError;





	if (MAJOR(dev->devt)) {

		error = device_create_file(dev, &dev_attr_dev);

		if (error)

			goto ueventattrError;



		error = device_create_sys_dev_entry(dev);

		if (error)

			goto devtattrError;



		devtmpfs_create_node(dev);

	}



	error = device_add_class_symlinks(dev);

	error = device_add_class_symlinks(dev);

	if (error)

	if (error)

		goto SymlinkError;

		goto SymlinkError;
@@ -1045,6 +1033,18 @@ int device_add(struct device *dev) 
		goto DPMError;

		goto DPMError;

	device_pm_add(dev);

	device_pm_add(dev);





	if (MAJOR(dev->devt)) {

		error = device_create_file(dev, &dev_attr_dev);

		if (error)

			goto DevAttrError;



		error = device_create_sys_dev_entry(dev);

		if (error)

			goto SysEntryError;



		devtmpfs_create_node(dev);

	}



	/* Notify clients of device addition.  This call must come

	/* Notify clients of device addition.  This call must come

	 * after dpm_sysfs_add() and before kobject_uevent().

	 * after dpm_sysfs_add() and before kobject_uevent().

	 */

	 */
@@ -1074,6 +1074,12 @@ int device_add(struct device *dev) 
done:

done:

	put_device(dev);

	put_device(dev);

	return error;

	return error;

 SysEntryError:

	if (MAJOR(dev->devt))

		device_remove_file(dev, &dev_attr_dev);

 DevAttrError:

	device_pm_remove(dev);

	dpm_sysfs_remove(dev);

 DPMError:

 DPMError:

	bus_remove_device(dev);

	bus_remove_device(dev);

 BusError:

 BusError:
@@ -1081,14 +1087,6 @@ int device_add(struct device *dev) 
 AttrsError:

 AttrsError:

	device_remove_class_symlinks(dev);

	device_remove_class_symlinks(dev);

 SymlinkError:

 SymlinkError:

	if (MAJOR(dev->devt))

		devtmpfs_delete_node(dev);

	if (MAJOR(dev->devt))

		device_remove_sys_dev_entry(dev);

 devtattrError:

	if (MAJOR(dev->devt))

		device_remove_file(dev, &dev_attr_dev);

 ueventattrError:

	device_remove_file(dev, &dev_attr_uevent);

	device_remove_file(dev, &dev_attr_uevent);

 attrError:

 attrError:

	kobject_uevent(&dev->kobj, KOBJ_REMOVE);

	kobject_uevent(&dev->kobj, KOBJ_REMOVE);