Merge tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are the "big" driver core patches for 4.9-rc1. Also in here are a
  number of debugfs fixes that cropped up due to the changes that
  happened in 4.8 for that filesystem. Overall, nothing major, just a
  few fixes and cleanups.

  All of these have been in linux-next with no reported issues"

* tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
  drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent()
  drivers: dma-coherent: Fix DMA coherent size for less than page
  MAINTAINERS: extend firmware_class maintainer list
  debugfs: propagate release() call result
  driver-core: platform: Catch errors from calls to irq_get_irq_data
  sysfs print name of undiscoverable attribute group
  carl9170: fix debugfs crashes
  b43legacy: fix debugfs crash
  b43: fix debugfs crash
  debugfs: introduce a public file_operations accessor
  device core: Remove deprecated create_singlethread_workqueue
  drivers/base dmam_declare_coherent_memory leaks
  platform: don't return 0 from platform_get_irq[_byname]() on error
  cpu: clean up register_cpu func
  dma-mapping: use vma_pages().
  drivers: dma-coherent: use vma_pages().
  attribute_container: Fix typo
  base: soc: make it explicitly non-modular
  drivers: base: dma-mapping: page align the size when unmap_kernel_range
  platform driver: fix use-after-free in platform_device_del()
  ...

drivers/base/core.c

@@ -836,11 +836,29 @@ static struct kobject *get_device_parent(struct device *dev,
 	return NULL;
 }
 
+static inline bool live_in_glue_dir(struct kobject *kobj,
+				    struct device *dev)
+{
+	if (!kobj || !dev->class ||
+	    kobj->kset != &dev->class->p->glue_dirs)
+		return false;
+	return true;
+}
+
+static inline struct kobject *get_glue_dir(struct device *dev)
+{
+	return dev->kobj.parent;
+}
+
+/*
+ * make sure cleaning up dir as the last step, we need to make
+ * sure .release handler of kobject is run with holding the
+ * global lock
+ */
 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 {
 	/* see if we live in a "glue" directory */
-	if (!glue_dir || !dev->class ||
-	    glue_dir->kset != &dev->class->p->glue_dirs)
+	if (!live_in_glue_dir(glue_dir, dev))
 		return;
 
 	mutex_lock(&gdp_mutex);
@@ -848,11 +866,6 @@ static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 	mutex_unlock(&gdp_mutex);
 }
 
-static void cleanup_device_parent(struct device *dev)
-{
-	cleanup_glue_dir(dev, dev->kobj.parent);
-}
-
 static int device_add_class_symlinks(struct device *dev)
 {
 	struct device_node *of_node = dev_of_node(dev);
@@ -1028,6 +1041,7 @@ int device_add(struct device *dev)
 	struct kobject *kobj;
 	struct class_interface *class_intf;
 	int error = -EINVAL;
+	struct kobject *glue_dir = NULL;
 
 	dev = get_device(dev);
 	if (!dev)
@@ -1072,8 +1086,10 @@ int device_add(struct device *dev)
 	/* first, register with generic layer. */
 	/* we require the name to be set before, and pass NULL */
 	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
-	if (error)
+	if (error) {
+		glue_dir = get_glue_dir(dev);
 		goto Error;
+	}
 
 	/* notify platform of device entry */
 	if (platform_notify)
@@ -1154,9 +1170,10 @@ done:
 	device_remove_file(dev, &dev_attr_uevent);
  attrError:
 	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
+	glue_dir = get_glue_dir(dev);
 	kobject_del(&dev->kobj);
  Error:
-	cleanup_device_parent(dev);
+	cleanup_glue_dir(dev, glue_dir);
 	put_device(parent);
 name_error:
 	kfree(dev->p);
@@ -1232,6 +1249,7 @@ EXPORT_SYMBOL_GPL(put_device);
 void device_del(struct device *dev)
 {
 	struct device *parent = dev->parent;
+	struct kobject *glue_dir = NULL;
 	struct class_interface *class_intf;
 
 	/* Notify clients of device removal.  This call must come
@@ -1277,8 +1295,9 @@ void device_del(struct device *dev)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_REMOVED_DEVICE, dev);
 	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
-	cleanup_device_parent(dev);
+	glue_dir = get_glue_dir(dev);
 	kobject_del(&dev->kobj);
+	cleanup_glue_dir(dev, glue_dir);
 	put_device(parent);
 }
 EXPORT_SYMBOL_GPL(device_del);