From 893ab00439a45513cae55781fc8e3b7108ee1cda Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 27 Jun 2020 03:59:12 +0900 Subject: kbuild: remove cc-option test of -fno-stack-protector Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Acked-by: Ard Biesheuvel Reviewed-by: Nick Desaulniers --- arch/x86/Makefile | 2 +- arch/x86/boot/compressed/Makefile | 2 +- arch/x86/entry/vdso/Makefile | 4 ++-- arch/x86/kernel/cpu/Makefile | 3 +-- arch/x86/lib/Makefile | 2 +- arch/x86/mm/Makefile | 7 +++---- arch/x86/power/Makefile | 3 +-- arch/x86/purgatory/Makefile | 2 +- arch/x86/um/vdso/Makefile | 2 +- arch/x86/xen/Makefile | 5 ++--- 10 files changed, 14 insertions(+), 18 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 00e378de8bc0..89c3cdfba753 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -37,7 +37,7 @@ REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \ -mno-mmx -mno-sse REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding) -REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -fno-stack-protector) +REALMODE_CFLAGS += -fno-stack-protector REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member) REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4)) export REALMODE_CFLAGS diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 7619742f91c9..c88a31569a5e 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -36,7 +36,7 @@ cflags-$(CONFIG_X86_64) := -mcmodel=small KBUILD_CFLAGS += $(cflags-y) KBUILD_CFLAGS += -mno-mmx -mno-sse KBUILD_CFLAGS += $(call cc-option,-ffreestanding) -KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) +KBUILD_CFLAGS += -fno-stack-protector KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) KBUILD_CFLAGS += $(call cc-disable-warning, gnu) KBUILD_CFLAGS += -Wno-pointer-sign diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 04e65f0698f6..215376d975a2 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -82,7 +82,7 @@ $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE # optimize sibling calls. # CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ - $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \ + $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ -fno-omit-frame-pointer -foptimize-sibling-calls \ -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO @@ -151,7 +151,7 @@ KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic -KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector) +KBUILD_CFLAGS_32 += -fno-stack-protector KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls) KBUILD_CFLAGS_32 += -fno-omit-frame-pointer KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index dba6a83bc349..93792b457b81 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -17,8 +17,7 @@ KCOV_INSTRUMENT_perf_event.o := n KCSAN_SANITIZE_common.o := n # Make sure load_percpu_segment has no stackprotector -nostackp := $(call cc-option, -fno-stack-protector) -CFLAGS_common.o := $(nostackp) +CFLAGS_common.o := -fno-stack-protector obj-y := cacheinfo.o scattered.o topology.o obj-y += common.o diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 6110bce7237b..d46fff11f06f 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -24,7 +24,7 @@ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_cmdline.o = -pg endif -CFLAGS_cmdline.o := $(call cc-option, -fno-stack-protector) +CFLAGS_cmdline.o := -fno-stack-protector endif inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index f7fd0e868c9c..5864219221ca 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -22,10 +22,9 @@ obj-y := init.o init_$(BITS).o fault.o ioremap.o extable.o mmap.o \ obj-y += pat/ # Make sure __phys_addr has no stackprotector -nostackp := $(call cc-option, -fno-stack-protector) -CFLAGS_physaddr.o := $(nostackp) -CFLAGS_setup_nx.o := $(nostackp) -CFLAGS_mem_encrypt_identity.o := $(nostackp) +CFLAGS_physaddr.o := -fno-stack-protector +CFLAGS_setup_nx.o := -fno-stack-protector +CFLAGS_mem_encrypt_identity.o := -fno-stack-protector CFLAGS_fault.o := -I $(srctree)/$(src)/../include/asm/trace diff --git a/arch/x86/power/Makefile b/arch/x86/power/Makefile index 37923d715741..6907b523e856 100644 --- a/arch/x86/power/Makefile +++ b/arch/x86/power/Makefile @@ -3,8 +3,7 @@ OBJECT_FILES_NON_STANDARD_hibernate_asm_$(BITS).o := y # __restore_processor_state() restores %gs after S3 resume and so should not # itself be stack-protected -nostackp := $(call cc-option, -fno-stack-protector) -CFLAGS_cpu.o := $(nostackp) +CFLAGS_cpu.o := -fno-stack-protector obj-$(CONFIG_PM_SLEEP) += cpu.o obj-$(CONFIG_HIBERNATION) += hibernate_$(BITS).o hibernate_asm_$(BITS).o hibernate.o diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 088bd764e0b7..183ac60e5990 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -34,7 +34,7 @@ KCOV_INSTRUMENT := n PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING -PURGATORY_CFLAGS += $(call cc-option,-fno-stack-protector) +PURGATORY_CFLAGS += -fno-stack-protector # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That # in turn leaves some undefined symbols like __fentry__ in purgatory and not diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile index 0caddd6acb22..5943387e3f35 100644 --- a/arch/x86/um/vdso/Makefile +++ b/arch/x86/um/vdso/Makefile @@ -42,7 +42,7 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE # optimize sibling calls. # CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ - $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \ + $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \ -fno-omit-frame-pointer -foptimize-sibling-calls $(vobjs): KBUILD_CFLAGS += $(CFL) diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 084de77a109e..5f1db522d06b 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -9,9 +9,8 @@ CFLAGS_REMOVE_irq.o = -pg endif # Make sure early boot has no stackprotector -nostackp := $(call cc-option, -fno-stack-protector) -CFLAGS_enlighten_pv.o := $(nostackp) -CFLAGS_mmu_pv.o := $(nostackp) +CFLAGS_enlighten_pv.o := -fno-stack-protector +CFLAGS_mmu_pv.o := -fno-stack-protector obj-y += enlighten.o obj-y += mmu.o -- cgit v1.2.3 From 685969e0bd732ff92e6626acc0c05f7204aa7ea6 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 27 Jun 2020 03:59:13 +0900 Subject: kbuild: remove cc-option test of -ffreestanding Some Makefiles already pass -ffreestanding unconditionally. For example, arch/arm64/lib/Makefile, arch/x86/purgatory/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -ffreestanding. I confirmed GCC 4.8 and Clang manuals document this option. Get rid of cc-option from -ffreestanding. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Reviewed-by: Kees Cook Acked-by: Ard Biesheuvel --- arch/s390/Makefile | 2 +- arch/x86/Makefile | 2 +- arch/x86/boot/compressed/Makefile | 2 +- drivers/firmware/efi/libstub/Makefile | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/x86') diff --git a/arch/s390/Makefile b/arch/s390/Makefile index 8dfa2cf1f05c..ba94b03c8b2f 100644 --- a/arch/s390/Makefile +++ b/arch/s390/Makefile @@ -27,7 +27,7 @@ KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2 KBUILD_CFLAGS_DECOMPRESSOR += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float KBUILD_CFLAGS_DECOMPRESSOR += -fno-asynchronous-unwind-tables -KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-option,-ffreestanding) +KBUILD_CFLAGS_DECOMPRESSOR += -ffreestanding KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-disable-warning, address-of-packed-member) KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),-g) KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO_DWARF4), $(call cc-option, -gdwarf-4,)) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 89c3cdfba753..edc68538a04e 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -36,7 +36,7 @@ REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ -mno-mmx -mno-sse -REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding) +REALMODE_CFLAGS += -ffreestanding REALMODE_CFLAGS += -fno-stack-protector REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member) REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4)) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index c88a31569a5e..b7beabecef8a 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -35,7 +35,7 @@ cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small KBUILD_CFLAGS += $(cflags-y) KBUILD_CFLAGS += -mno-mmx -mno-sse -KBUILD_CFLAGS += $(call cc-option,-ffreestanding) +KBUILD_CFLAGS += -ffreestanding KBUILD_CFLAGS += -fno-stack-protector KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) KBUILD_CFLAGS += $(call cc-disable-warning, gnu) diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 12c4436e77fb..2a156f7fec3b 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -29,7 +29,7 @@ cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt KBUILD_CFLAGS := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \ -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \ -D__NO_FORTIFY \ - $(call cc-option,-ffreestanding) \ + -ffreestanding \ -fno-stack-protector \ $(call cc-option,-fno-addrsig) \ -D__DISABLE_EXPORTS -- cgit v1.2.3