+KBUILD_CFLAGS += $(call cc-option,-U_FORTIFY_SOURCE)
+
KBUILD_CFLAGS += $(cflags-y)
+--- a/arch/um/Makefile-x86_64
++++ b/arch/um/Makefile-x86_64
+@@ -24,3 +24,7 @@ LINK-y += -m64
+
+ # Do unit-at-a-time unconditionally on x86_64, following the host
+ KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
++
++# disable compile-time buffer checks, enabled by default on Ubuntu 8.10
++# and later
++KBUILD_CFLAGS += $(call cc-option,-U_FORTIFY_SOURCE)