Merge "driver core: fix race between creating/querying glue dir and its cleanup" (1057dedd) · Commits · e / devices / android_kernel_sony_msm8998

drivers/base/core.c

+29 −10

Original line number	Diff line number	Diff line
		@@ -841,11 +841,29 @@ 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);
		@@ -853,11 +871,6 @@ 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);
		@@ -1033,6 +1046,7 @@ 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)
		@@ -1077,8 +1091,10 @@ 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)
		@@ -1159,9 +1175,10 @@ 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);
		@@ -1237,6 +1254,7 @@ 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
		@@ -1281,8 +1299,9 @@ 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);