From: Segher Boessenkool <seg...@kernel.crashing.org> Newer gcc will support "-mno-readonly-in-sdata"[1], which makes sure that the optimization on PPC32 for variables getting moved into the .sdata section will not apply to const variables (which must be in .rodata).
This was originally noticed in mm/rodata_test.c when rodata_test_data was not static: c0695034 g O .data 00000004 rodata_test_data After this patch with an updated compiler, this is correctly in .rodata. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82411 Reported-by: Christophe Leroy <christophe.le...@c-s.fr> Signed-off-by: Segher Boessenkool <seg...@kernel.crashing.org> Signed-off-by: Kees Cook <keesc...@chromium.org> --- arch/powerpc/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index ccd2556bdb53..c7628e973084 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -141,7 +141,9 @@ AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1) endif CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc)) 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) -- 2.7.4 -- Kees Cook Pixel Security
