diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 04fb513..8e54108 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -266,6 +266,10 @@
 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
 #endif
 
+/* Compile time object size, -1 for unknown */
+#ifndef __compiletime_object_size
+# define __compiletime_object_size(obj) -1
+#endif
 /*
  * Prevent the compiler from merging or refetching accesses.  The compiler
  * is also forbidden from reordering successive instances of ACCESS_ONCE(),