arch/x86/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 # Unified Makefile for i386 and x86_64
   3
   4 # select defconfig based on actual architecture
   5 ifeq ($(ARCH),x86)
   6   ifeq ($(shell uname -m | sed -e 's/i.86/i386/'),i386)
   7         KBUILD_DEFCONFIG := i386_defconfig
   8   else
   9         KBUILD_DEFCONFIG := x86_64_defconfig
  10   endif
  11 else
  12         KBUILD_DEFCONFIG := $(ARCH)_defconfig
  13 endif
  14
  15 ifdef CONFIG_CC_IS_GCC
  16 RETPOLINE_CFLAGS        := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
  17 RETPOLINE_VDSO_CFLAGS   := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
  18 endif
  19 ifdef CONFIG_CC_IS_CLANG
  20 RETPOLINE_CFLAGS        := -mretpoline-external-thunk
  21 RETPOLINE_VDSO_CFLAGS   := -mretpoline
  22 endif
  23 RETPOLINE_CFLAGS        += $(call cc-option,-mindirect-branch-cs-prefix)
  24
  25 ifdef CONFIG_MITIGATION_RETHUNK
  26 RETHUNK_CFLAGS          := -mfunction-return=thunk-extern
  27 RETPOLINE_CFLAGS        += $(RETHUNK_CFLAGS)
  28 endif
  29
  30 export RETHUNK_CFLAGS
  31 export RETPOLINE_CFLAGS
  32 export RETPOLINE_VDSO_CFLAGS
  33
  34 # For gcc stack alignment is specified with -mpreferred-stack-boundary,
  35 # clang has the option -mstack-alignment for that purpose.
  36 ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
  37       cc_stack_align4 := -mpreferred-stack-boundary=2
  38       cc_stack_align8 := -mpreferred-stack-boundary=3
  39 else ifneq ($(call cc-option, -mstack-alignment=16),)
  40       cc_stack_align4 := -mstack-alignment=4
  41       cc_stack_align8 := -mstack-alignment=8
  42 endif
  43
  44 # How to compile the 16-bit code.  Note we always compile for -march=i386;
  45 # that way we can complain to the user if the CPU is insufficient.
  46 REALMODE_CFLAGS := -std=gnu11 -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
  47                    -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
  48                    -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
  49                    -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
  50
  51 REALMODE_CFLAGS += -ffreestanding
  52 REALMODE_CFLAGS += -fno-stack-protector
  53 REALMODE_CFLAGS += -Wno-address-of-packed-member
  54 REALMODE_CFLAGS += $(cc_stack_align4)
  55 REALMODE_CFLAGS += $(CLANG_FLAGS)
  56 export REALMODE_CFLAGS
  57
  58 # BITS is used as extension for files which are available in a 32 bit
  59 # and a 64 bit version to simplify shared Makefiles.
  60 # e.g.: obj-y += foo_$(BITS).o
  61 export BITS
  62
  63 #
  64 # Prevent GCC from generating any FP code by mistake.
  65 #
  66 # This must happen before we try the -mpreferred-stack-boundary, see:
  67 #
  68 #    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
  69 #
  70 KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx
  71 KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
  72
  73 ifeq ($(CONFIG_X86_KERNEL_IBT),y)
  74 #
  75 # Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate
  76 # NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK
  77 # for jump-tables, as such, disable jump-tables for now.
  78 #
  79 # (jump-tables are implicitly disabled by RETPOLINE)
  80 #
  81 #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
  82 #
  83 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables)
  84 KBUILD_RUSTFLAGS += -Zcf-protection=branch -Zno-jump-tables
  85 else
  86 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
  87 endif
  88
  89 ifeq ($(CONFIG_X86_32),y)
  90         BITS := 32
  91         UTS_MACHINE := i386
  92         CHECKFLAGS += -D__i386__
  93
  94         KBUILD_AFLAGS += -m32
  95         KBUILD_CFLAGS += -m32
  96
  97         KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
  98
  99         # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
 100         # with nonstandard options
 101         KBUILD_CFLAGS += -fno-pic
 102
 103         # Align the stack to the register width instead of using the default
 104         # alignment of 16 bytes. This reduces stack usage and the number of
 105         # alignment instructions.
 106         KBUILD_CFLAGS += $(cc_stack_align4)
 107
 108         # CPU-specific tuning. Anything which can be shared with UML should go here.
 109         include $(srctree)/arch/x86/Makefile_32.cpu
 110         KBUILD_CFLAGS += $(cflags-y)
 111
 112         # temporary until string.h is fixed
 113         KBUILD_CFLAGS += -ffreestanding
 114
 115         ifeq ($(CONFIG_STACKPROTECTOR),y)
 116                 ifeq ($(CONFIG_SMP),y)
 117                         KBUILD_CFLAGS += -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard
 118                 else
 119                         KBUILD_CFLAGS += -mstack-protector-guard=global
 120                 endif
 121         endif
 122 else
 123         BITS := 64
 124         UTS_MACHINE := x86_64
 125         CHECKFLAGS += -D__x86_64__
 126
 127         KBUILD_AFLAGS += -m64
 128         KBUILD_CFLAGS += -m64
 129
 130         # Align jump targets to 1 byte, not the default 16 bytes:
 131         KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
 132
 133         # Pack loops tightly as well:
 134         KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
 135
 136         # Don't autogenerate traditional x87 instructions
 137         KBUILD_CFLAGS += -mno-80387
 138         KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
 139
 140         # By default gcc and clang use a stack alignment of 16 bytes for x86.
 141         # However the standard kernel entry on x86-64 leaves the stack on an
 142         # 8-byte boundary. If the compiler isn't informed about the actual
 143         # alignment it will generate extra alignment instructions for the
 144         # default alignment which keep the stack *mis*aligned.
 145         # Furthermore an alignment to the register width reduces stack usage
 146         # and the number of alignment instructions.
 147         KBUILD_CFLAGS += $(cc_stack_align8)
 148
 149         # Use -mskip-rax-setup if supported.
 150         KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
 151
 152         # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
 153         cflags-$(CONFIG_MK8)            += -march=k8
 154         cflags-$(CONFIG_MPSC)           += -march=nocona
 155         cflags-$(CONFIG_MCORE2)         += -march=core2
 156         cflags-$(CONFIG_MATOM)          += -march=atom
 157         cflags-$(CONFIG_GENERIC_CPU)    += -mtune=generic
 158         KBUILD_CFLAGS += $(cflags-y)
 159
 160         rustflags-$(CONFIG_MK8)         += -Ctarget-cpu=k8
 161         rustflags-$(CONFIG_MPSC)        += -Ctarget-cpu=nocona
 162         rustflags-$(CONFIG_MCORE2)      += -Ctarget-cpu=core2
 163         rustflags-$(CONFIG_MATOM)       += -Ctarget-cpu=atom
 164         rustflags-$(CONFIG_GENERIC_CPU) += -Ztune-cpu=generic
 165         KBUILD_RUSTFLAGS += $(rustflags-y)
 166
 167         KBUILD_CFLAGS += -mno-red-zone
 168         KBUILD_CFLAGS += -mcmodel=kernel
 169         KBUILD_RUSTFLAGS += -Cno-redzone=y
 170         KBUILD_RUSTFLAGS += -Ccode-model=kernel
 171 endif
 172
 173 #
 174 # If the function graph tracer is used with mcount instead of fentry,
 175 # '-maccumulate-outgoing-args' is needed to prevent a GCC bug
 176 # (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
 177 #
 178 ifdef CONFIG_FUNCTION_GRAPH_TRACER
 179   ifndef CONFIG_HAVE_FENTRY
 180         ACCUMULATE_OUTGOING_ARGS := 1
 181   endif
 182 endif
 183
 184 ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
 185         # This compiler flag is not supported by Clang:
 186         KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
 187 endif
 188
 189 # Workaround for a gcc prelease that unfortunately was shipped in a suse release
 190 KBUILD_CFLAGS += -Wno-sign-compare
 191 #
 192 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 193
 194 # Avoid indirect branches in kernel to deal with Spectre
 195 ifdef CONFIG_MITIGATION_RETPOLINE
 196   KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
 197   # Additionally, avoid generating expensive indirect jumps which
 198   # are subject to retpolines for small number of switch cases.
 199   # clang turns off jump table generation by default when under
 200   # retpoline builds, however, gcc does not for x86. This has
 201   # only been fixed starting from gcc stable version 8.4.0 and
 202   # onwards, but not for older ones. See gcc bug #86952.
 203   ifndef CONFIG_CC_IS_CLANG
 204     KBUILD_CFLAGS += -fno-jump-tables
 205   endif
 206 endif
 207
 208 ifdef CONFIG_MITIGATION_SLS
 209   KBUILD_CFLAGS += -mharden-sls=all
 210 endif
 211
 212 ifdef CONFIG_CALL_PADDING
 213 PADDING_CFLAGS := -fpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES)
 214 KBUILD_CFLAGS += $(PADDING_CFLAGS)
 215 export PADDING_CFLAGS
 216 endif
 217
 218 KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)
 219
 220 ifdef CONFIG_LTO_CLANG
 221 ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
 222 KBUILD_LDFLAGS  += -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8)
 223 endif
 224 endif
 225
 226 ifdef CONFIG_X86_NEED_RELOCS
 227 LDFLAGS_vmlinux := --emit-relocs --discard-none
 228 else
 229 LDFLAGS_vmlinux :=
 230 endif
 231
 232 #
 233 # The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
 234 # the linker to force 2MB page size regardless of the default page size used
 235 # by the linker.
 236 #
 237 ifdef CONFIG_X86_64
 238 LDFLAGS_vmlinux += -z max-page-size=0x200000
 239 endif
 240
 241
 242 archscripts: scripts_basic
 243         $(Q)$(MAKE) $(build)=arch/x86/tools relocs
 244
 245 ###
 246 # Syscall table generation
 247
 248 archheaders:
 249         $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
 250
 251 ###
 252 # Kernel objects
 253
 254 libs-y  += arch/x86/lib/
 255
 256 core-y += arch/x86/virt/
 257
 258 # drivers-y are linked after core-y
 259 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 260 drivers-$(CONFIG_PCI)            += arch/x86/pci/
 261
 262 # suspend and hibernation support
 263 drivers-$(CONFIG_PM) += arch/x86/power/
 264
 265 drivers-$(CONFIG_FB_CORE) += arch/x86/video/
 266
 267 ####
 268 # boot loader support. Several targets are kept for legacy purposes
 269
 270 boot := arch/x86/boot
 271
 272 BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage
 273
 274 PHONY += bzImage $(BOOT_TARGETS)
 275
 276 # Default kernel to build
 277 all: bzImage
 278
 279 # KBUILD_IMAGE specify target image being built
 280 KBUILD_IMAGE := $(boot)/bzImage
 281
 282 bzImage: vmlinux
 283 ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
 284         $(Q)$(MAKE) $(build)=arch/x86/tools posttest
 285 endif
 286         $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
 287         $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
 288         $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
 289
 290 $(BOOT_TARGETS): vmlinux
 291         $(Q)$(MAKE) $(build)=$(boot) $@
 292
 293 PHONY += install
 294 install:
 295         $(call cmd,install)
 296
 297 vdso-install-$(CONFIG_X86_64)           += arch/x86/entry/vdso/vdso64.so.dbg
 298 vdso-install-$(CONFIG_X86_X32_ABI)      += arch/x86/entry/vdso/vdsox32.so.dbg
 299 vdso-install-$(CONFIG_X86_32)           += arch/x86/entry/vdso/vdso32.so.dbg
 300 vdso-install-$(CONFIG_IA32_EMULATION)   += arch/x86/entry/vdso/vdso32.so.dbg
 301
 302 archprepare: checkbin
 303 checkbin:
 304 ifdef CONFIG_MITIGATION_RETPOLINE
 305 ifeq ($(RETPOLINE_CFLAGS),)
 306         @echo "You are building kernel with non-retpoline compiler." >&2
 307         @echo "Please update your compiler." >&2
 308         @false
 309 endif
 310 endif
 311
 312 ifdef CONFIG_UNWINDER_ORC
 313 orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h
 314 orc_hash_sh := $(srctree)/scripts/orc_hash.sh
 315 targets += $(orc_hash_h)
 316 quiet_cmd_orc_hash = GEN     $@
 317       cmd_orc_hash = mkdir -p $(dir $@); \
 318                      $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@
 319 $(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE
 320         $(call if_changed,orc_hash)
 321 archprepare: $(orc_hash_h)
 322 endif
 323
 324 archclean:
 325         $(Q)rm -rf $(objtree)/arch/i386
 326         $(Q)rm -rf $(objtree)/arch/x86_64
 327
 328 define archhelp
 329   echo  '* bzImage              - Compressed kernel image (arch/x86/boot/bzImage)'
 330   echo  '  install              - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or'
 331   echo  '                         (distribution) /sbin/$(INSTALLKERNEL) or install to '
 332   echo  '                         $$(INSTALL_PATH) and run lilo'
 333   echo  ''
 334   echo  '  fdimage              - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 335   echo  '  fdimage144           - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 336   echo  '  fdimage288           - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
 337   echo  '  hdimage              - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)'
 338   echo  '  isoimage             - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
 339   echo  '                         bzdisk/fdimage*/hdimage/isoimage also accept:'
 340   echo  '                         FDARGS="..."  arguments for the booted kernel'
 341   echo  '                         FDINITRD=file initrd for the booted kernel'
 342
 343 endef