diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index 6a4fe8b4e686..d0fc1862da95 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -59,11 +59,6 @@ static inline void release_thread(struct task_struct *task)
 {
 }
 
-static inline void mm_copy_segments(struct mm_struct *from_mm,
-				    struct mm_struct *new_mm)
-{
-}
-
 /*
  * User space process size: 3GB (default).
  */