Index: sys/compat/linuxkpi/common/include/linux/mm.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/mm.h
+++ sys/compat/linuxkpi/common/include/linux/mm.h
@@ -353,4 +353,6 @@
 {
 }
 
+#define	is_cow_mapping(flags)	(false)
+
 #endif					/* _LINUXKPI_LINUX_MM_H_ */