On Wed, Feb 28, 2018 at 04:43:56PM -0800, Kees Cook wrote: > On Wed, Feb 28, 2018 at 4:39 PM, Segher Boessenkool > <seg...@kernel.crashing.org> wrote: > > On Wed, Feb 28, 2018 at 04:15:23PM -0800, Kees Cook wrote: > >> On Wed, Feb 28, 2018 at 3:23 PM, Segher Boessenkool > >> <seg...@kernel.crashing.org> wrote: > >> > I'm trying to figure out how to get that file to build at all :-) > > > >> $ CROSS_COMPILE=powerpc-linux-gnu- ARCH=powerpc make wii_defconfig > >> $ for i in CONFIG_STRICT_KERNEL_RWX \ > >> CONFIG_DEBUG_KERNEL \ > >> CONFIG_DEBUG_RODATA_TEST ; do > >> CROSS_COMPILE=powerpc-linux-gnu- ARCH=powerpc ./scripts/config -e $i > >> done > > > > I use ppc6xx_defconfig normally; I had to disable CONFIG_HIBERNATION > > as well. > > > > Without the new flag, rodata_test_data ends up in .sdata in the object > > file and in .data in vmlinux. > > > > Adding > > > > === > > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile > > index ccd2556..31b9613 100644 > > --- a/arch/powerpc/Makefile > > +++ b/arch/powerpc/Makefile > > @@ -143,6 +143,8 @@ CFLAGS-$(CONFIG_PPC64) += $(call > > cc-option,-mcmodel=med > > CFLAGS-$(CONFIG_PPC64) += $(call > > cc-option,-mno-pointers-to-nested-functions) > > CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 $(MULTIPLEWORD) > > > > +CFLAGS-$(CONFIG_PPC32) += $(call cc-option,-mno-readonly-in-sdata) > > + > > ifeq ($(CONFIG_PPC_BOOK3S_64),y) > > CFLAGS-$(CONFIG_GENERIC_CPU) += $(call > > cc-option,-mtune=power7,-mtune=power4) > > CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power4 > > === > > > > it ends up in .rodata in both. > > Excellent! That's perfect. :) > > > It would be nice to have a more comprehensive test, but this will do; I'll > > commit it tomorrow (will resend, with doc and changelog and all that). > > Thank you! Do you want to send the Makefile fix upstream too, or > should I route that?
If you could? Have my Signed-off-by: Segher Boessenkool <seg...@kernel.crashing.org> if you want. It'll be a while before all users have a compiler with the new flag, but I'll backport it to GCC 7 and GCC 6 (the open release branches) to speed that up a bit. Segher
