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-rw-r--r--arch/x86/Makefile373
1 files changed, 248 insertions, 125 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 07639c656fcd..1d403a3612ea 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -1,33 +1,117 @@
+# SPDX-License-Identifier: GPL-2.0
# 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
+ ifeq ($(shell uname -m | sed -e 's/i.86/i386/'),i386)
KBUILD_DEFCONFIG := i386_defconfig
+ else
+ KBUILD_DEFCONFIG := x86_64_defconfig
endif
else
KBUILD_DEFCONFIG := $(ARCH)_defconfig
endif
+ifdef CONFIG_CC_IS_GCC
+RETPOLINE_CFLAGS := -mindirect-branch=thunk-extern -mindirect-branch-register
+RETPOLINE_VDSO_CFLAGS := -mindirect-branch=thunk-inline -mindirect-branch-register
+endif
+ifdef CONFIG_CC_IS_CLANG
+RETPOLINE_CFLAGS := -mretpoline-external-thunk
+RETPOLINE_VDSO_CFLAGS := -mretpoline
+endif
+RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix)
+
+ifdef CONFIG_MITIGATION_RETHUNK
+RETHUNK_CFLAGS := -mfunction-return=thunk-extern
+RETHUNK_RUSTFLAGS := -Zfunction-return=thunk-extern
+RETPOLINE_CFLAGS += $(RETHUNK_CFLAGS)
+RETPOLINE_RUSTFLAGS += $(RETHUNK_RUSTFLAGS)
+endif
+
+export RETHUNK_CFLAGS
+export RETHUNK_RUSTFLAGS
+export RETPOLINE_CFLAGS
+export RETPOLINE_RUSTFLAGS
+export RETPOLINE_VDSO_CFLAGS
+
+# For gcc stack alignment is specified with -mpreferred-stack-boundary,
+# clang has the option -mstack-alignment for that purpose.
+ifdef CONFIG_CC_IS_GCC
+ cc_stack_align4 := -mpreferred-stack-boundary=2
+ cc_stack_align8 := -mpreferred-stack-boundary=3
+endif
+ifdef CONFIG_CC_IS_CLANG
+ 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.
+REALMODE_CFLAGS := -std=gnu11 -fms-extensions -m16 -g -Os \
+ -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
+ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
+ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
+ -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
+
+REALMODE_CFLAGS += -ffreestanding
+REALMODE_CFLAGS += -fno-stack-protector
+REALMODE_CFLAGS += -Wno-address-of-packed-member
+REALMODE_CFLAGS += $(cc_stack_align4)
+REALMODE_CFLAGS += $(CLANG_FLAGS)
+ifdef CONFIG_CC_IS_CLANG
+REALMODE_CFLAGS += -Wno-gnu
+REALMODE_CFLAGS += -Wno-microsoft-anon-tag
+endif
+export REALMODE_CFLAGS
+
# BITS is used as extension for files which are available in a 32 bit
# and a 64 bit version to simplify shared Makefiles.
# e.g.: obj-y += foo_$(BITS).o
export BITS
+#
+# 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 -mno-avx -mno-sse4a
+KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json
+KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
+
+#
+# CFLAGS for compiling floating point code inside the kernel.
+#
+CC_FLAGS_FPU := -msse -msse2
+ifdef CONFIG_CC_IS_GCC
+CC_FLAGS_FPU += -mhard-float
+endif
+
+ifeq ($(CONFIG_X86_KERNEL_IBT),y)
+#
+# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate
+# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK
+# for jump-tables, as such, disable jump-tables for now.
+#
+# (jump-tables are implicitly disabled by RETPOLINE)
+#
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
+#
+KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables)
+KBUILD_RUSTFLAGS += -Zcf-protection=branch $(if $(call rustc-min-version,109300),-Cjump-tables=n,-Zno-jump-tables)
+else
+KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
+endif
+
ifeq ($(CONFIG_X86_32),y)
BITS := 32
UTS_MACHINE := i386
CHECKFLAGS += -D__i386__
- biarch := $(call cc-option,-m32)
- KBUILD_AFLAGS += $(biarch)
- KBUILD_CFLAGS += $(biarch)
-
- ifdef CONFIG_RELOCATABLE
- LDFLAGS_vmlinux := --emit-relocs
- endif
+ KBUILD_AFLAGS += -m32
+ KBUILD_CFLAGS += -m32
KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
@@ -35,117 +119,137 @@ ifeq ($(CONFIG_X86_32),y)
# with nonstandard options
KBUILD_CFLAGS += -fno-pic
- # prevent gcc from keeping the stack 16 byte aligned
- KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
-
- # 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))
+ # 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 += $(cc_stack_align4)
# CPU-specific tuning. Anything which can be shared with UML should go here.
include $(srctree)/arch/x86/Makefile_32.cpu
KBUILD_CFLAGS += $(cflags-y)
- # temporary until string.h is fixed
+ ifneq ($(call clang-min-version, 160000),y)
+ # https://github.com/llvm/llvm-project/issues/53645
KBUILD_CFLAGS += -ffreestanding
+ endif
+
+ percpu_seg := fs
else
BITS := 64
UTS_MACHINE := x86_64
- CHECKFLAGS += -D__x86_64__ -m64
+ CHECKFLAGS += -D__x86_64__
KBUILD_AFLAGS += -m64
KBUILD_CFLAGS += -m64
- # Use -mpreferred-stack-boundary=3 if supported.
- KBUILD_CFLAGS += $(call cc-option,-mno-sse -mpreferred-stack-boundary=3)
+ # Align jump targets to 1 byte, not the default 16 bytes:
+ KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
- # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
- cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
- cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
+ # Pack loops tightly as well:
+ KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
- cflags-$(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)
+ # Don't autogenerate traditional x87 instructions
+ KBUILD_CFLAGS += -mno-80387
+ KBUILD_CFLAGS += -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 += $(cc_stack_align8)
+
+ # Use -mskip-rax-setup if supported.
+ KBUILD_CFLAGS += -mskip-rax-setup
+
+ifdef CONFIG_X86_NATIVE_CPU
+ KBUILD_CFLAGS += -march=native
+ KBUILD_RUSTFLAGS += -Ctarget-cpu=native
+else
+ KBUILD_CFLAGS += -march=x86-64 -mtune=generic
+ KBUILD_RUSTFLAGS += -Ctarget-cpu=x86-64 -Ztune-cpu=generic
+endif
KBUILD_CFLAGS += -mno-red-zone
KBUILD_CFLAGS += -mcmodel=kernel
+ KBUILD_RUSTFLAGS += -Cno-redzone=y
+ KBUILD_RUSTFLAGS += -Ccode-model=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)
-
- # this works around some issues with generating unwind tables in older gccs
- # newer gccs do it by default
- KBUILD_CFLAGS += -maccumulate-outgoing-args
+ percpu_seg := gs
endif
-ifdef CONFIG_CC_STACKPROTECTOR
- cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh
- ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
- stackp-y := -fstack-protector
- KBUILD_CFLAGS += $(stackp-y)
- else
- $(warning stack protector enabled but no compiler support)
- endif
+ifeq ($(CONFIG_STACKPROTECTOR),y)
+ ifeq ($(CONFIG_SMP),y)
+ KBUILD_CFLAGS += -mstack-protector-guard-reg=$(percpu_seg)
+ KBUILD_CFLAGS += -mstack-protector-guard-symbol=__ref_stack_chk_guard
+ else
+ KBUILD_CFLAGS += -mstack-protector-guard=global
+ endif
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
+#
+# 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
+ 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)
+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
+# Workaround for a gcc prelease that unfortunately was shipped in a suse release
+KBUILD_CFLAGS += -Wno-sign-compare
+#
+KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
-# 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)
+# Avoid indirect branches in kernel to deal with Spectre
+ifdef CONFIG_MITIGATION_RETPOLINE
+ KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
+ KBUILD_RUSTFLAGS += $(RETPOLINE_RUSTFLAGS)
+ # Additionally, avoid generating expensive indirect jumps which
+ # are subject to retpolines for small number of switch cases.
+ # LLVM turns off jump table generation by default when under
+ # retpoline builds, however, gcc does not for x86. This has
+ # only been fixed starting from gcc stable version 8.4.0 and
+ # onwards, but not for older ones. See gcc bug #86952.
+ ifndef CONFIG_CC_IS_CLANG
+ KBUILD_CFLAGS += -fno-jump-tables
+ endif
+endif
-# does binutils support specific instructions?
-asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=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)
+ifdef CONFIG_MITIGATION_SLS
+ KBUILD_CFLAGS += -mharden-sls=all
+endif
-KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr)
-KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) $(avx_instr) $(avx2_instr)
+ifdef CONFIG_CALL_PADDING
+PADDING_CFLAGS := -fpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES)
+KBUILD_CFLAGS += $(PADDING_CFLAGS)
+export PADDING_CFLAGS
-LDFLAGS := -m elf_$(UTS_MACHINE)
+PADDING_RUSTFLAGS := -Zpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES)
+KBUILD_RUSTFLAGS += $(PADDING_RUSTFLAGS)
+export PADDING_RUSTFLAGS
+endif
+
+KBUILD_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
-# prevent gcc from generating any FP code by mistake
-KBUILD_CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
-KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
+# The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to
+# the linker to force 2MB page size regardless of the default page size used
+# by the linker.
+#
+ifdef CONFIG_X86_64
+LDFLAGS_vmlinux += -z max-page-size=0x200000
+endif
-KBUILD_CFLAGS += $(mflags-y)
-KBUILD_AFLAGS += $(mflags-y)
archscripts: scripts_basic
$(Q)$(MAKE) $(build)=arch/x86/tools relocs
@@ -154,38 +258,42 @@ archscripts: scripts_basic
# Syscall table generation
archheaders:
- $(Q)$(MAKE) $(build)=arch/x86/syscalls all
+ $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
###
-# Kernel objects
+# <asm/cpufeaturemasks.h> header generation
-head-y := arch/x86/kernel/head_$(BITS).o
-head-y += arch/x86/kernel/head$(BITS).o
-head-y += arch/x86/kernel/head.o
+cpufeaturemasks.hdr := arch/x86/include/generated/asm/cpufeaturemasks.h
+cpufeaturemasks.awk := $(srctree)/arch/x86/tools/cpufeaturemasks.awk
+cpufeatures_hdr := $(srctree)/arch/x86/include/asm/cpufeatures.h
+targets += $(cpufeaturemasks.hdr)
+ filechk_gen_featuremasks = $(AWK) -f $(cpufeaturemasks.awk) $(cpufeatures_hdr) $(KCONFIG_CONFIG)
-libs-y += arch/x86/lib/
+$(cpufeaturemasks.hdr): $(cpufeaturemasks.awk) $(cpufeatures_hdr) $(KCONFIG_CONFIG) FORCE
+ $(shell mkdir -p $(dir $@))
+ $(call filechk,gen_featuremasks)
+archprepare: $(cpufeaturemasks.hdr)
-# See arch/x86/Kbuild for content of core part of the kernel
-core-y += arch/x86/
+###
+# Kernel objects
+
+libs-y += arch/x86/lib/
# 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/
+drivers-$(CONFIG_VIDEO) += 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
+BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage
PHONY += bzImage $(BOOT_TARGETS)
@@ -208,36 +316,51 @@ $(BOOT_TARGETS): vmlinux
PHONY += install
install:
- $(Q)$(MAKE) $(build)=$(boot) $@
+ $(call cmd,install)
+
+vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg
+vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg
+vdso-install-$(CONFIG_COMPAT_32) += arch/x86/entry/vdso/vdso32.so.dbg
+
+archprepare: checkbin
+checkbin:
+ifdef CONFIG_MITIGATION_RETPOLINE
+ifeq ($(RETPOLINE_CFLAGS),)
+ @echo "You are building kernel with non-retpoline compiler." >&2
+ @echo "Please update your compiler." >&2
+ @false
+endif
+endif
-PHONY += vdso_install
-vdso_install:
- $(Q)$(MAKE) $(build)=arch/x86/vdso $@
+ifdef CONFIG_UNWINDER_ORC
+orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h
+orc_hash_sh := $(srctree)/scripts/orc_hash.sh
+targets += $(orc_hash_h)
+quiet_cmd_orc_hash = GEN $@
+ cmd_orc_hash = mkdir -p $(dir $@); \
+ $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@
+$(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE
+ $(call if_changed,orc_hash)
+archprepare: $(orc_hash_h)
+endif
archclean:
$(Q)rm -rf $(objtree)/arch/i386
$(Q)rm -rf $(objtree)/arch/x86_64
- $(Q)$(MAKE) $(clean)=$(boot)
- $(Q)$(MAKE) $(clean)=arch/x86/tools
-
-PHONY += kvmconfig
-kvmconfig:
- $(if $(wildcard $(objtree)/.config),, $(error You need an existing .config for this target))
- $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m -O $(objtree) $(objtree)/.config arch/x86/configs/kvm_guest.config
- $(Q)yes "" | $(MAKE) oldconfig
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'
- echo ' kvmconfig - Enable additional options for guest kernel support'
+ echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)'
+ echo ' install - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or'
+ echo ' (distribution) /sbin/$(INSTALLKERNEL) or install to '
+ echo ' $$(INSTALL_PATH) and run lilo'
+ echo ''
+ 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 ' hdimage - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)'
+ echo ' isoimage - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
+ echo ' bzdisk/fdimage*/hdimage/isoimage also accept:'
+ echo ' FDARGS="..." arguments for the booted kernel'
+ echo ' FDINITRD=file initrd for the booted kernel'
+
endef
generated by cgit (git 2.34.1) at 2025-12-28 02:18:01 +0000