--- a/Makefile +++ b/Makefile @@ -438,7 +438,7 @@ KBUILD_AFLAGS := -D__ASSEMBLY__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common -fshort-wchar \ -Werror-implicit-function-declaration \ - -Wno-format-security \ + -Werror=return-type -Wno-format-security \ -std=gnu89 KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_AFLAGS_KERNEL :=