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>

1 files changed, 18 insertions, 20 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 14d162952c3b..00ec7ce6f3e3 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1019,18 +1019,6 @@ int device_add(struct device *dev)
         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 @@ int device_add(struct device *dev)
                 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 @@ int device_add(struct device *dev)
 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 @@ done:
  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);