mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Matthias Kaehlcke](/assets/img/avatar_default.png)
With the following commit:8f91869766
("x86/build: Fix stack alignment for CLang") cc-option is only used to determine the name of the stack alignment option supported by the compiler, but not to verify that the actual parameter <option>=N is valid in combination with the other CFLAGS. This causes problems (as reported by the kbuild robot) with older GCC versions which only support stack alignment on a boundary of 16 bytes or higher. Also use (__)cc_option to add the stack alignment option to CFLAGS to make sure only valid options are added. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bernhard.Rosenkranzer@linaro.org Cc: Greg Hackmann <ghackmann@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hines <srhines@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dianders@chromium.org Fixes:8f91869766
("x86/build: Fix stack alignment for CLang") Link: http://lkml.kernel.org/r/20170817182047.176752-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
330 lines
12 KiB
Makefile
330 lines
12 KiB
Makefile
# Unified Makefile for i386 and x86_64
|
|
|
|
# select defconfig based on actual architecture
|
|
ifeq ($(ARCH),x86)
|
|
ifeq ($(shell uname -m),x86_64)
|
|
KBUILD_DEFCONFIG := x86_64_defconfig
|
|
else
|
|
KBUILD_DEFCONFIG := i386_defconfig
|
|
endif
|
|
else
|
|
KBUILD_DEFCONFIG := $(ARCH)_defconfig
|
|
endif
|
|
|
|
# For gcc stack alignment is specified with -mpreferred-stack-boundary,
|
|
# clang has the option -mstack-alignment for that purpose.
|
|
ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
|
|
cc_stack_align4 := -mpreferred-stack-boundary=2
|
|
cc_stack_align8 := -mpreferred-stack-boundary=3
|
|
else ifneq ($(call cc-option, -mstack-alignment=16),)
|
|
cc_stack_align4 := -mstack-alignment=4
|
|
cc_stack_align8 := -mstack-alignment=8
|
|
endif
|
|
|
|
# How to compile the 16-bit code. Note we always compile for -march=i386;
|
|
# that way we can complain to the user if the CPU is insufficient.
|
|
#
|
|
# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For
|
|
# older versions of GCC, include an *assembly* header to make sure that
|
|
# gcc doesn't play any games behind our back.
|
|
CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
|
|
M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
|
|
|
|
REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \
|
|
-DDISABLE_BRANCH_PROFILING \
|
|
-Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
|
|
-fno-strict-aliasing -fomit-frame-pointer -fno-pic \
|
|
-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 += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
|
|
export REALMODE_CFLAGS
|
|
|
|
# BITS is used as extension for files which are available in a 32 bit
|
|
# and a 64 bit version to simplify shared Makefiles.
|
|
# e.g.: obj-y += foo_$(BITS).o
|
|
export BITS
|
|
|
|
ifdef CONFIG_X86_NEED_RELOCS
|
|
LDFLAGS_vmlinux := --emit-relocs
|
|
endif
|
|
|
|
#
|
|
# Prevent GCC from generating any FP code by mistake.
|
|
#
|
|
# This must happen before we try the -mpreferred-stack-boundary, see:
|
|
#
|
|
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
|
|
#
|
|
KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
|
|
|
|
ifeq ($(CONFIG_X86_32),y)
|
|
BITS := 32
|
|
UTS_MACHINE := i386
|
|
CHECKFLAGS += -D__i386__
|
|
|
|
biarch := $(call cc-option,-m32)
|
|
KBUILD_AFLAGS += $(biarch)
|
|
KBUILD_CFLAGS += $(biarch)
|
|
|
|
KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
|
|
|
|
# Never want PIC in a 32-bit kernel, prevent breakage with GCC built
|
|
# with nonstandard options
|
|
KBUILD_CFLAGS += -fno-pic
|
|
|
|
# Align the stack to the register width instead of using the default
|
|
# alignment of 16 bytes. This reduces stack usage and the number of
|
|
# alignment instructions.
|
|
KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align4))
|
|
|
|
# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
|
|
# a lot more stack due to the lack of sharing of stacklots:
|
|
KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0400, \
|
|
$(call cc-option,-fno-unit-at-a-time))
|
|
|
|
# CPU-specific tuning. Anything which can be shared with UML should go here.
|
|
include arch/x86/Makefile_32.cpu
|
|
KBUILD_CFLAGS += $(cflags-y)
|
|
|
|
# temporary until string.h is fixed
|
|
KBUILD_CFLAGS += -ffreestanding
|
|
else
|
|
BITS := 64
|
|
UTS_MACHINE := x86_64
|
|
CHECKFLAGS += -D__x86_64__ -m64
|
|
|
|
biarch := -m64
|
|
KBUILD_AFLAGS += -m64
|
|
KBUILD_CFLAGS += -m64
|
|
|
|
# Align jump targets to 1 byte, not the default 16 bytes:
|
|
KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
|
|
|
|
# Pack loops tightly as well:
|
|
KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
|
|
|
|
# Don't autogenerate traditional x87 instructions
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-80387)
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
|
|
|
|
# By default gcc and clang use a stack alignment of 16 bytes for x86.
|
|
# However the standard kernel entry on x86-64 leaves the stack on an
|
|
# 8-byte boundary. If the compiler isn't informed about the actual
|
|
# alignment it will generate extra alignment instructions for the
|
|
# default alignment which keep the stack *mis*aligned.
|
|
# Furthermore an alignment to the register width reduces stack usage
|
|
# and the number of alignment instructions.
|
|
KBUILD_CFLAGS += $(call cc-option,$(cc_stack_align8))
|
|
|
|
# Use -mskip-rax-setup if supported.
|
|
KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
|
|
|
|
# FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
|
|
cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
|
|
cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
|
|
|
|
cflags-$(CONFIG_MCORE2) += \
|
|
$(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
|
|
cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
|
|
$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
|
|
cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
|
|
KBUILD_CFLAGS += $(cflags-y)
|
|
|
|
KBUILD_CFLAGS += -mno-red-zone
|
|
KBUILD_CFLAGS += -mcmodel=kernel
|
|
|
|
# -funit-at-a-time shrinks the kernel .text considerably
|
|
# unfortunately it makes reading oopses harder.
|
|
KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)
|
|
endif
|
|
|
|
ifdef CONFIG_X86_X32
|
|
x32_ld_ok := $(call try-run,\
|
|
/bin/echo -e '1: .quad 1b' | \
|
|
$(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
|
|
$(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMPO" && \
|
|
$(LD) -m elf32_x86_64 "$$TMPO" -o "$$TMP",y,n)
|
|
ifeq ($(x32_ld_ok),y)
|
|
CONFIG_X86_X32_ABI := y
|
|
KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
|
|
KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
|
|
else
|
|
$(warning CONFIG_X86_X32 enabled but no binutils support)
|
|
endif
|
|
endif
|
|
export CONFIG_X86_X32_ABI
|
|
|
|
# Don't unroll struct assignments with kmemcheck enabled
|
|
ifeq ($(CONFIG_KMEMCHECK),y)
|
|
KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy)
|
|
endif
|
|
|
|
#
|
|
# If the function graph tracer is used with mcount instead of fentry,
|
|
# '-maccumulate-outgoing-args' is needed to prevent a GCC bug
|
|
# (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
|
|
#
|
|
ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
ifndef CONFIG_HAVE_FENTRY
|
|
ACCUMULATE_OUTGOING_ARGS := 1
|
|
else
|
|
ifeq ($(call cc-option-yn, -mfentry), n)
|
|
ACCUMULATE_OUTGOING_ARGS := 1
|
|
|
|
# GCC ignores '-maccumulate-outgoing-args' when used with '-Os'.
|
|
# If '-Os' is enabled, disable it and print a warning.
|
|
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
|
|
undefine CONFIG_CC_OPTIMIZE_FOR_SIZE
|
|
$(warning Disabling CONFIG_CC_OPTIMIZE_FOR_SIZE. Your compiler does not have -mfentry so you cannot optimize for size with CONFIG_FUNCTION_GRAPH_TRACER.)
|
|
endif
|
|
|
|
endif
|
|
endif
|
|
endif
|
|
|
|
#
|
|
# Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
|
|
# GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226). There's no way
|
|
# to test for this bug at compile-time because the test case needs to execute,
|
|
# which is a no-go for cross compilers. So check the GCC version instead.
|
|
#
|
|
ifdef CONFIG_JUMP_LABEL
|
|
ifneq ($(ACCUMULATE_OUTGOING_ARGS), 1)
|
|
ACCUMULATE_OUTGOING_ARGS = $(call cc-if-fullversion, -lt, 040502, 1)
|
|
endif
|
|
endif
|
|
|
|
ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
|
|
# This compiler flag is not supported by Clang:
|
|
KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
|
|
endif
|
|
|
|
# Stackpointer is addressed different for 32 bit and 64 bit x86
|
|
sp-$(CONFIG_X86_32) := esp
|
|
sp-$(CONFIG_X86_64) := rsp
|
|
|
|
# do binutils support CFI?
|
|
cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
|
|
# is .cfi_signal_frame supported too?
|
|
cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1)
|
|
cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1)
|
|
|
|
# does binutils support specific instructions?
|
|
asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)
|
|
asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1)
|
|
asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)
|
|
avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)
|
|
avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)
|
|
avx512_instr :=$(call as-instr,vpmovm2b %k1$(comma)%zmm5,-DCONFIG_AS_AVX512=1)
|
|
sha1_ni_instr :=$(call as-instr,sha1msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA1_NI=1)
|
|
sha256_ni_instr :=$(call as-instr,sha256msg1 %xmm0$(comma)%xmm1,-DCONFIG_AS_SHA256_NI=1)
|
|
|
|
KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
|
|
KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr) $(avx512_instr) $(sha1_ni_instr) $(sha256_ni_instr)
|
|
|
|
LDFLAGS := -m elf_$(UTS_MACHINE)
|
|
|
|
# Speed up the build
|
|
KBUILD_CFLAGS += -pipe
|
|
# Workaround for a gcc prelease that unfortunately was shipped in a suse release
|
|
KBUILD_CFLAGS += -Wno-sign-compare
|
|
#
|
|
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
|
|
|
|
archscripts: scripts_basic
|
|
$(Q)$(MAKE) $(build)=arch/x86/tools relocs
|
|
|
|
###
|
|
# Syscall table generation
|
|
|
|
archheaders:
|
|
$(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
|
|
|
|
archprepare:
|
|
ifeq ($(CONFIG_KEXEC_FILE),y)
|
|
$(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
|
|
endif
|
|
|
|
###
|
|
# Kernel objects
|
|
|
|
head-y := arch/x86/kernel/head_$(BITS).o
|
|
head-y += arch/x86/kernel/head$(BITS).o
|
|
head-y += arch/x86/kernel/ebda.o
|
|
head-y += arch/x86/kernel/platform-quirks.o
|
|
|
|
libs-y += arch/x86/lib/
|
|
|
|
# See arch/x86/Kbuild for content of core part of the kernel
|
|
core-y += arch/x86/
|
|
|
|
# drivers-y are linked after core-y
|
|
drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
|
|
drivers-$(CONFIG_PCI) += arch/x86/pci/
|
|
|
|
# must be linked after kernel/
|
|
drivers-$(CONFIG_OPROFILE) += arch/x86/oprofile/
|
|
|
|
# suspend and hibernation support
|
|
drivers-$(CONFIG_PM) += arch/x86/power/
|
|
|
|
drivers-$(CONFIG_FB) += arch/x86/video/
|
|
|
|
####
|
|
# boot loader support. Several targets are kept for legacy purposes
|
|
|
|
boot := arch/x86/boot
|
|
|
|
BOOT_TARGETS = bzlilo bzdisk fdimage fdimage144 fdimage288 isoimage
|
|
|
|
PHONY += bzImage $(BOOT_TARGETS)
|
|
|
|
# Default kernel to build
|
|
all: bzImage
|
|
|
|
# KBUILD_IMAGE specify target image being built
|
|
KBUILD_IMAGE := $(boot)/bzImage
|
|
|
|
bzImage: vmlinux
|
|
ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
|
|
$(Q)$(MAKE) $(build)=arch/x86/tools posttest
|
|
endif
|
|
$(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
|
|
$(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
|
|
$(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
|
|
|
|
$(BOOT_TARGETS): vmlinux
|
|
$(Q)$(MAKE) $(build)=$(boot) $@
|
|
|
|
PHONY += install
|
|
install:
|
|
$(Q)$(MAKE) $(build)=$(boot) $@
|
|
|
|
PHONY += vdso_install
|
|
vdso_install:
|
|
$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
|
|
|
|
archclean:
|
|
$(Q)rm -rf $(objtree)/arch/i386
|
|
$(Q)rm -rf $(objtree)/arch/x86_64
|
|
$(Q)$(MAKE) $(clean)=$(boot)
|
|
$(Q)$(MAKE) $(clean)=arch/x86/tools
|
|
$(Q)$(MAKE) $(clean)=arch/x86/purgatory
|
|
|
|
define archhelp
|
|
echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)'
|
|
echo ' install - Install kernel using'
|
|
echo ' (your) ~/bin/$(INSTALLKERNEL) or'
|
|
echo ' (distribution) /sbin/$(INSTALLKERNEL) or'
|
|
echo ' install to $$(INSTALL_PATH) and run lilo'
|
|
echo ' fdimage - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
|
|
echo ' fdimage144 - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
|
|
echo ' fdimage288 - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
|
|
echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
|
|
echo ' bzdisk/fdimage*/isoimage also accept:'
|
|
echo ' FDARGS="..." arguments for the booted kernel'
|
|
echo ' FDINITRD=file initrd for the booted kernel'
|
|
endef
|