On Tue, Oct 22, 2019 at 9:28 AM Mark Rutland <mark.rutland@xxxxxxx> wrote: > I think it would be preferable to follow the example of CC_FLAGS_FTRACE > so that this can be filtered out, e.g. > > ifdef CONFIG_SHADOW_CALL_STACK > CFLAGS_SCS := -fsanitize=shadow-call-stack > KBUILD_CFLAGS += $(CFLAGS_SCS) > export CC_FLAGS_SCS > endif > > ... with removal being: > > CFLAGS_REMOVE := $(CC_FLAGS_SCS) > > ... or: > > CFLAGS_REMOVE_obj.o := $(CC_FLAGS_SCS) > > That way you only need to define the flags once, so the enable and > disable falgs remain in sync by construction. CFLAGS_REMOVE appears to be only implemented for objects, which means there's no convenient way to filter out flags for everything in arch/arm64/kvm/hyp, for example. I could add a CFLAGS_REMOVE separately for each object file, or we could add something like ccflags-remove-y to complement ccflags-y, which should be relatively simple. Masahiro, do you have any suggestions? Sami
