From 51d42f0f5fd6c74144d19bf6a663521e2ea99765 Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Wed, 28 Feb 2018 17:02:49 -0800 Subject: [PATCH] powerpc: Keep const vars out of writable .sdata 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 Signed-off-by: Segher Boessenkool Signed-off-by: Kees Cook Signed-off-by: Michael Ellerman --- arch/powerpc/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index ccd2556..c7628e9 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