On Tue, 14 Aug 2018 09:33:52 +0100 Julien Thierry <julien.thierry@xxxxxxx> wrote: > On 14/08/18 03:03, Steven Rostedt wrote: > > On Mon, 13 Aug 2018 11:54:06 +0100 > > Julien Thierry <julien.thierry@xxxxxxx> wrote: > > > >>> --- a/arch/arm64/Makefile > >>> +++ b/arch/arm64/Makefile > >>> @@ -78,6 +78,15 @@ ifeq ($(CONFIG_ARM64_MODULE_PLTS),y) > >>> KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm64/kernel/module.lds > >>> endif > >>> > >>> +ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > >>> + CC_FLAGS_FTRACE := -fpatchable-function-entry=2 > >>> + KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY > >>> + ifeq ($(call cc-option,-fpatchable-function-entry=2),) > >>> + $(warning Cannot use CONFIG_DYNAMIC_FTRACE_WITH_REGS: \ > >>> + -fpatchable-function-entry not supported by compiler) > >> > >> Shouldn't this be an error? The option -fpatchable-function-entry has > >> been added to the CC_FLAGS_FTRACE, so any call to the compiler is gonna > >> break anyway. Or am I missing something? > > > > I'm guessing this adds a more informative message on that error. One > > will know why -fpatchable-function-entry was added to the CFLAGS. I'm > > for more informative error messages being a victim of poor error > > messages causing me to dig deep into the guts of the build > > infrastructure to figure out simple issues. > > > > Yes, I agree it is better to have this message. My point was that we > could have "$error" instead of "$warning" to stop the compilation right > away since we know everything is gonna break (and on parallel builds > this warning is gonna be drowned in compiler errors). > OK, I see what you mean. If the resulting build wont boot, then yes this should be an error and not a warning. -- Steve
