1 files changed, 17 insertions, 45 deletions

diff --git a/drivers/acpi/acpica/excreate.c b/drivers/acpi/acpica/excreate.c
index d43d7da4c734..b8adb11f1b07 100644
--- a/drivers/acpi/acpica/excreate.c
+++ b/drivers/acpi/acpica/excreate.c
@@ -87,68 +87,40 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
 				  target_node->object);
 	}
 
-	/*
-	 * For objects that can never change (i.e., the NS node will
-	 * permanently point to the same object), we can simply attach
-	 * the object to the new NS node. For other objects (such as
-	 * Integers, buffers, etc.), we have to point the Alias node
-	 * to the original Node.
-	 */
-	switch (target_node->type) {
+	/* Ensure that the target node is valid */
 
-		/* For these types, the sub-object can change dynamically via a Store */
+	if (!target_node) {
+		return_ACPI_STATUS(AE_NULL_OBJECT);
+	}
 
-	case ACPI_TYPE_INTEGER:
-	case ACPI_TYPE_STRING:
-	case ACPI_TYPE_BUFFER:
-	case ACPI_TYPE_PACKAGE:
-	case ACPI_TYPE_BUFFER_FIELD:
-		/*
-		 * These types open a new scope, so we need the NS node in order to access
-		 * any children.
-		 */
-	case ACPI_TYPE_DEVICE:
-	case ACPI_TYPE_POWER:
-	case ACPI_TYPE_PROCESSOR:
-	case ACPI_TYPE_THERMAL:
-	case ACPI_TYPE_LOCAL_SCOPE:
-		/*
-		 * The new alias has the type ALIAS and points to the original
-		 * NS node, not the object itself.
-		 */
-		alias_node->type = ACPI_TYPE_LOCAL_ALIAS;
-		alias_node->object =
-		    ACPI_CAST_PTR(union acpi_operand_object, target_node);
-		break;
+	/* Construct the alias object (a namespace node) */
 
+	switch (target_node->type) {
 	case ACPI_TYPE_METHOD:
 		/*
-		 * Control method aliases need to be differentiated
+		 * Control method aliases need to be differentiated with
+		 * a special type
 		 */
 		alias_node->type = ACPI_TYPE_LOCAL_METHOD_ALIAS;
-		alias_node->object =
-		    ACPI_CAST_PTR(union acpi_operand_object, target_node);
 		break;
 
 	default:
-
-		/* Attach the original source object to the new Alias Node */
-
 		/*
-		 * The new alias assumes the type of the target, and it points
-		 * to the same object. The reference count of the object has an
-		 * additional reference to prevent deletion out from under either the
-		 * target node or the alias Node
+		 * All other object types.
+		 *
+		 * The new alias has the type ALIAS and points to the original
+		 * NS node, not the object itself.
 		 */
-		status = acpi_ns_attach_object(alias_node,
-					       acpi_ns_get_attached_object
-					       (target_node),
-					       target_node->type);
+		alias_node->type = ACPI_TYPE_LOCAL_ALIAS;
+		alias_node->object =
+		    ACPI_CAST_PTR(union acpi_operand_object, target_node);
 		break;
 	}
 
 	/* Since both operands are Nodes, we don't need to delete them */
 
+	alias_node->object =
+	    ACPI_CAST_PTR(union acpi_operand_object, target_node);
 	return_ACPI_STATUS(status);
 }