[RFC] class_device_add needs error checks

[Stephen Hemminger <shemminger@osdl.org>]

class_device_add needs to check the return value of all the setup functions
it calls. It doesn't handle out of memory well. 

This is not complete, probably more needs to be done, and the unwind
may not work right.

--- linux-2.6.orig/drivers/base/class.c	2006-04-21 12:21:21.000000000 -0700
+++ linux-2.6/drivers/base/class.c	2006-04-21 12:41:48.000000000 -0700
@@ -546,7 +546,10 @@
 		 class_dev->class_id);
 
 	/* first, register with generic layer. */
-	kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
+	error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
+	if (error)
+		goto register_done;
+
 	if (parent_class_dev)
 		class_dev->kobj.parent = &parent_class_dev->kobj;
 	else
@@ -561,34 +564,49 @@
 	class_dev->uevent_attr.attr.mode = S_IWUSR;
 	class_dev->uevent_attr.attr.owner = parent_class->owner;
 	class_dev->uevent_attr.store = store_uevent;
-	class_device_create_file(class_dev, &class_dev->uevent_attr);
+	error = class_device_create_file(class_dev, &class_dev->uevent_attr);
+	if (error)
+		goto register_done;
 
 	if (MAJOR(class_dev->devt)) {
 		struct class_device_attribute *attr;
 		attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 		if (!attr) {
 			error = -ENOMEM;
-			kobject_del(&class_dev->kobj);
 			goto register_done;
 		}
 		attr->attr.name = "dev";
 		attr->attr.mode = S_IRUGO;
 		attr->attr.owner = parent_class->owner;
 		attr->show = show_dev;
-		class_device_create_file(class_dev, attr);
+		error = class_device_create_file(class_dev, attr);
+		if (error) {
+			kfree(attr);
+			goto register_done;
+		}
+
 		class_dev->devt_attr = attr;
 	}
 
-	class_device_add_attrs(class_dev);
+	error = class_device_add_attrs(class_dev);
+	if (error)
+		goto register_done;
+
 	if (class_dev->dev) {
 		class_name = make_class_name(class_dev);
-		sysfs_create_link(&class_dev->kobj,
-				  &class_dev->dev->kobj, "device");
-		sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
-				  class_name);
+		error = sysfs_create_link(&class_dev->kobj,
+					  &class_dev->dev->kobj, "device");
+		if (error)
+			goto register_done;
+		error = sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
+					  class_name);
+		if (error)
+			goto register_done;
 	}
 
-	class_device_add_groups(class_dev);
+	error = class_device_add_groups(class_dev);
+	if (error)
+		goto register_done;
 
 	kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 
@@ -603,6 +621,15 @@
 
  register_done:
 	if (error) {
+		sysfs_remove_link(&class_dev->kobj, "device");
+		sysfs_remove_link(&class_dev->dev->kobj, class_name);
+		class_device_remove_attrs(class_dev);
+		class_device_remove_file(class_dev, &class_dev->uevent_attr);
+		if (class_dev->devt_attr)
+			class_device_remove_file(class_dev, class_dev->devt_attr);
+
+		if (atomic_read(&class_dev->kobj.kref.refcount))
+			kobject_del(&class_dev->kobj);
 		class_put(parent_class);
 		class_device_put(parent_class_dev);
 	}
-
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