On Tue, Aug 17, 2021 at 3:36 AM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > On Fri, Aug 13, 2021 at 6:43 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > > > On Wed, Aug 11, 2021 at 5:42 AM Nick Desaulniers > > <ndesaulniers@xxxxxxxxxx> wrote: > > > > > > --param=allow-store-data-races=0 was renamed to --allow-store-data-races > > > in the GCC 10 release. > > > > > > diff --git a/Makefile b/Makefile > > > index 027fdf2a14fe..3e3fb4affba1 100644 > > > --- a/Makefile > > > +++ b/Makefile > > > @@ -844,17 +847,17 @@ KBUILD_RUSTFLAGS += -Copt-level=z > > > endif > > > > > > # Tell gcc to never replace conditional load with a non-conditional one > > > -KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) > > > +ifdef CONFIG_CC_IS_GCC > > > > > > Can you insert a comment here? > > > > # GCC 10 renamed --param=allow-store-data-races=0 to --allow-store-data-races > > > > > > It will remind us of dropping this conditional > > in the (long long distant) future. > > > > > > > > > > > +KBUILD_CFLAGS += $(call cc-option,--allow-store-data-races,--param=allow-store-data-races=0) > > > KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races) > > > +endif > > This report is confusing: > https://lore.kernel.org/linux-mm/202108160729.Lx0IJzq3-lkp@xxxxxxxxx/ > (csky gcc-11) > > >> csky-linux-gcc: error: unrecognized command-line option '--param=allow-store-data-races=0'; did you mean '--allow-store-data-races'? > > I wonder if cc-option detection for these is broken? I do not say it is broken... cc-option is defined like this: cc-option = $(call __cc-option, $(CC),\ $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2)) It is checking $(KBUILD_CPPFLAGS) + $(KBUILD_CFLAGS) + --allow-store-data-races A few lines above, I see csky-linux-gcc: error: unrecognized argument in option '-mcpu=ck860' It makes all the cc-option tests fail after this line: KBUILD_CFLAGS += -mcpu=$(CPUTYPE) -Wa,-mcpu=$(MCPU_STR) Then, $(call cc-option,--allow-store-data-races,--param=allow-store-data-races=0) falls back to --param=allow-store-data-races=0 > Perhaps I should > not touch these other than to wrap them in the CONFIG_CC_IS_GCC guard? I do not think so. If an unrecognized argument appears, all the cc-option tests that follow are unreliable. If you are not comfortable with it, you can split it. KBUILD_CFLAGS += $(call cc-option,--allow-store-data-races) KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) Or, another way of implementation is KBUILD_CFLAGS += $(call cc-ifversion, -lt, 1000, --allow-store-data-races, --param=allow-store-data-races=0) > > (Either way, I need to send a v2 in response to Naresh's report as > well. https://lore.kernel.org/lkml/CA+G9fYtPBp_-Ko_P7NuOX6vN9-66rjJuBt21h3arrLqEaQQn6w@xxxxxxxxxxxxxx/ > It seems that -mfentry wasn't implemented for s390-linux-gnu-gcc until > gcc-9; so rather than remove top level support, perhaps a comment > about gcc-9+ s390 having support will make grepping for it easier in > the future). > -- > Thanks, > ~Nick Desaulniers -- Best Regards Masahiro Yamada
