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: Sergey Klyaus <Sergey.Klyaus@Tune-IT.Ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 14d1629..00ec7ce 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1019,18 +1019,6 @@
if (error)
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);
if (error)
goto SymlinkError;
@@ -1045,6 +1033,18 @@
goto DPMError;
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
* after dpm_sysfs_add() and before kobject_uevent().
*/
@@ -1074,6 +1074,12 @@
done:
put_device(dev);
return error;
+ SysEntryError:
+ if (MAJOR(dev->devt))
+ device_remove_file(dev, &dev_attr_dev);
+ DevAttrError:
+ device_pm_remove(dev);
+ dpm_sysfs_remove(dev);
DPMError:
bus_remove_device(dev);
BusError:
@@ -1081,14 +1087,6 @@
AttrsError:
device_remove_class_symlinks(dev);
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);
attrError:
kobject_uevent(&dev->kobj, KOBJ_REMOVE);