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 should always be '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 <masahiroy@xxxxxxxxxx> --- Documentation/kbuild/kconfig-language.rst | 4 ++-- Makefile | 2 +- arch/Kconfig | 3 --- arch/arm/boot/compressed/Makefile | 3 +-- arch/mips/vdso/Makefile | 3 +-- arch/powerpc/kernel/Makefile | 2 +- arch/powerpc/platforms/powermac/Makefile | 2 +- arch/sparc/vdso/Makefile | 4 ++-- arch/um/Makefile | 3 +-- 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 ++--- drivers/firmware/efi/libstub/Makefile | 2 +- drivers/xen/Makefile | 3 +-- kernel/kcsan/Makefile | 3 +-- lib/Makefile | 4 ++-- mm/kasan/Makefile | 2 +- 24 files changed, 30 insertions(+), 42 deletions(-) diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst index a1601ec3317b..2538e7cb08e6 100644 --- a/Documentation/kbuild/kconfig-language.rst +++ b/Documentation/kbuild/kconfig-language.rst @@ -540,8 +540,8 @@ followed by a test macro:: If you need to expose a compiler capability to makefiles and/or C source files, `CC_HAS_` is the recommended prefix for the config option:: - config CC_HAS_STACKPROTECTOR_NONE - def_bool $(cc-option,-fno-stack-protector) + config CC_HAS_ASM_GOTO + def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC)) Build as module only ~~~~~~~~~~~~~~~~~~~~ diff --git a/Makefile b/Makefile index 5496a32dffa6..73948798ce3f 100644 --- a/Makefile +++ b/Makefile @@ -762,7 +762,7 @@ ifneq ($(CONFIG_FRAME_WARN),0) KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN) endif -stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector +stackp-flags-y := -fno-stack-protector stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong diff --git a/arch/Kconfig b/arch/Kconfig index 8cc35dc556c7..1ea61290900a 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -478,9 +478,6 @@ config HAVE_STACKPROTECTOR An arch should select this symbol if: - it has implemented a stack canary (e.g. __stack_chk_guard) -config CC_HAS_STACKPROTECTOR_NONE - def_bool $(cc-option,-fno-stack-protector) - config STACKPROTECTOR bool "Stack Protector buffer overflow detection" depends on HAVE_STACKPROTECTOR diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 00602a6fba04..cb7a56c6723c 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -84,9 +84,8 @@ endif # -fstack-protector-strong triggers protection checks in this code, # but it is being used too early to link to meaningful stack_chk logic. -nossp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector $(foreach o, $(libfdt_objs) atags_to_fdt.o, \ - $(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt $(nossp-flags-y))) + $(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt -fno-stack-protector)) # These were previously generated C files. When you are building the kernel # with O=, make sure to remove the stale files in the output tree. Otherwise, diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index 2e64c7600eea..57fe83235281 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -35,8 +35,7 @@ cflags-vdso := $(ccflags-vdso) \ -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ -mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \ -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ - $(call cc-option, -fno-asynchronous-unwind-tables) \ - $(call cc-option, -fno-stack-protector) + $(call cc-option, -fno-asynchronous-unwind-tables) aflags-vdso := $(ccflags-vdso) \ -D__ASSEMBLY__ -Wa,-gdwarf-2 diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 244542ae2a91..3a83f2b876a5 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -16,7 +16,7 @@ CFLAGS_prom_init.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) CFLAGS_btext.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) CFLAGS_prom.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) -CFLAGS_prom_init.o += $(call cc-option, -fno-stack-protector) +CFLAGS_prom_init.o += -fno-stack-protector CFLAGS_prom_init.o += -DDISABLE_BRANCH_PROFILING CFLAGS_prom_init.o += -ffreestanding diff --git a/arch/powerpc/platforms/powermac/Makefile b/arch/powerpc/platforms/powermac/Makefile index f4247ade71ca..cf85f0662d0d 100644 --- a/arch/powerpc/platforms/powermac/Makefile +++ b/arch/powerpc/platforms/powermac/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS_bootx_init.o += -fPIC -CFLAGS_bootx_init.o += $(call cc-option, -fno-stack-protector) +CFLAGS_bootx_init.o += -fno-stack-protector KASAN_SANITIZE_bootx_init.o := n diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile index 708cb6304c2d..f44355e46f31 100644 --- a/arch/sparc/vdso/Makefile +++ b/arch/sparc/vdso/Makefile @@ -54,7 +54,7 @@ $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE # optimize sibling calls. # CFL := $(PROFILING) -mcmodel=medlow -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 @@ -93,7 +93,7 @@ KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 := $(filter-out $(SPARC_REG_CFLAGS),$(KBUILD_CFLAGS_32)) KBUILD_CFLAGS_32 += -m32 -msoft-float -fpic -KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector) +KBUILD_CFLAGS_32 += -fno-stack-protector KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls) KBUILD_CFLAGS_32 += -fno-omit-frame-pointer KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING diff --git a/arch/um/Makefile b/arch/um/Makefile index 3f27aa3ec0a6..1cea46ff9bb7 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -121,8 +121,7 @@ LINK-$(CONFIG_LD_SCRIPT_STATIC) += -static LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib $(call cc-option, -no-pie) CFLAGS_NO_HARDENING := $(call cc-option, -fno-PIC,) $(call cc-option, -fno-pic,) \ - $(call cc-option, -fno-stack-protector,) \ - $(call cc-option, -fno-stack-protector-all,) + -fno-stack-protector $(call cc-option, -fno-stack-protector-all) # Options used by linker script export LDS_START := $(START) 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 diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 75daaf20374e..f8418763cd79 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -29,7 +29,7 @@ KBUILD_CFLAGS := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \ -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \ -D__NO_FORTIFY \ $(call cc-option,-ffreestanding) \ - $(call cc-option,-fno-stack-protector) \ + -fno-stack-protector \ $(call cc-option,-fno-addrsig) \ -D__DISABLE_EXPORTS diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index 0d322f3d90cd..c25c9a699b48 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -5,8 +5,7 @@ obj-y += mem-reservation.o obj-y += events/ obj-y += xenbus/ -nostackp := $(call cc-option, -fno-stack-protector) -CFLAGS_features.o := $(nostackp) +CFLAGS_features.o := -fno-stack-protector dom0-$(CONFIG_ARM64) += arm-device.o dom0-$(CONFIG_PCI) += pci.o diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile index d4999b38d1be..d111f32bd5fd 100644 --- a/kernel/kcsan/Makefile +++ b/kernel/kcsan/Makefile @@ -7,8 +7,7 @@ CFLAGS_REMOVE_core.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_debugfs.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) -CFLAGS_core.o := $(call cc-option,-fno-conserve-stack,) \ - $(call cc-option,-fno-stack-protector,) +CFLAGS_core.o := $(call cc-option,-fno-conserve-stack,) -fno-stack-protector obj-y := core.o debugfs.o report.o obj-$(CONFIG_KCSAN_SELFTEST) += test.o diff --git a/lib/Makefile b/lib/Makefile index b1c42c10073b..0cda70649f1c 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -22,7 +22,7 @@ KCOV_INSTRUMENT_fault-inject.o := n ifdef CONFIG_AMD_MEM_ENCRYPT KASAN_SANITIZE_string.o := n -CFLAGS_string.o := $(call cc-option, -fno-stack-protector) +CFLAGS_string.o := -fno-stack-protector endif # Used by KCSAN while enabled, avoid recursion. @@ -300,7 +300,7 @@ endif UBSAN_SANITIZE_ubsan.o := n KASAN_SANITIZE_ubsan.o := n KCSAN_SANITIZE_ubsan.o := n -CFLAGS_ubsan.o := $(call cc-option, -fno-stack-protector) $(DISABLE_STACKLEAK_PLUGIN) +CFLAGS_ubsan.o := -fno-stack-protector $(DISABLE_STACKLEAK_PLUGIN) obj-$(CONFIG_SBITMAP) += sbitmap.o diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index d532c2587731..370d970e5ab5 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -16,7 +16,7 @@ CFLAGS_REMOVE_tags_report.o = $(CC_FLAGS_FTRACE) # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 CC_FLAGS_KASAN_RUNTIME := $(call cc-option, -fno-conserve-stack) -CC_FLAGS_KASAN_RUNTIME += $(call cc-option, -fno-stack-protector) +CC_FLAGS_KASAN_RUNTIME += -fno-stack-protector # Disable branch tracing to avoid recursion. CC_FLAGS_KASAN_RUNTIME += -DDISABLE_BRANCH_PROFILING -- 2.25.1
