On Wed, 07 Feb 2018 12:07:55 +0000 David Woodhouse <dwmw2@xxxxxxxxxxxxx> wrote: > On Wed, 2018-02-07 at 11:07 +0100, Pavel Machek wrote: > > This is really unfortunate naming of kernel option. > > > > spectre_v2=off sounds like we are turning the "bug" off, but i somehow > > suspect you are turning the bug _workaround_ off. > > That's consistent with what we have on x86. > > > > +ifdef CONFIG_EXPOLINE > > > + ifeq ($(call cc-option-yn,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),y) > > > + CC_FLAGS_EXPOLINE := -mindirect-branch=thunk > > > + CC_FLAGS_EXPOLINE += -mfunction-return=thunk > > > + CC_FLAGS_EXPOLINE += -mindirect-branch-table > > > + export CC_FLAGS_EXPOLINE > > > + cflags-y += $(CC_FLAGS_EXPOLINE) > > > + else > > > + $(warning "Your gcc lacks the -mindirect-branch= option") > > > + endif > > > +endif > > That isn't, though. Linus asked us to drop the $(warning) part. > > ... and then spent a week building with a non-retpoline compiler and > not noticing, so he might have changed his mind ;) I found the warning to have some value, it helps for the case where my fingers are faster than my brain and I type "make" instead of "smake" which uses the alternative compiler with the required support. @Linus: do you want a warning or prefer not to have one ? -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
