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 RETHUNK_RUSTFLAGS       := -Zfunction-return=thunk-extern
  28 RETPOLINE_CFLAGS        += $(RETHUNK_CFLAGS)
  29 RETPOLINE_RUSTFLAGS     += $(RETHUNK_RUSTFLAGS)
  30 endif
  31
  32 export RETHUNK_CFLAGS
  33 export RETHUNK_RUSTFLAGS
  34 export RETPOLINE_CFLAGS
  35 export RETPOLINE_RUSTFLAGS
  36 export RETPOLINE_VDSO_CFLAGS
  37
  38 # For gcc stack alignment is specified with -mpreferred-stack-boundary,
  39 # clang has the option -mstack-alignment for that purpose.
  40 ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
  41       cc_stack_align4 := -mpreferred-stack-boundary=2
  42       cc_stack_align8 := -mpreferred-stack-boundary=3
  43 else ifneq ($(call cc-option, -mstack-alignment=16),)
  44       cc_stack_align4 := -mstack-alignment=4
  45       cc_stack_align8 := -mstack-alignment=8
  46 endif
  47
  48 # How to compile the 16-bit code.  Note we always compile for -march=i386;
  49 # that way we can complain to the user if the CPU is insufficient.
  50 REALMODE_CFLAGS := -std=gnu11 -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
  51                    -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
  52                    -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
  53                    -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
  54
  55 REALMODE_CFLAGS += -ffreestanding
  56 REALMODE_CFLAGS += -fno-stack-protector
  57 REALMODE_CFLAGS += -Wno-address-of-packed-member
  58 REALMODE_CFLAGS += $(cc_stack_align4)
  59 REALMODE_CFLAGS += $(CLANG_FLAGS)
  60 ifdef CONFIG_CC_IS_CLANG
  61 REALMODE_CFLAGS += -Wno-gnu
  62 endif
  63 export REALMODE_CFLAGS
  64
  65 # BITS is used as extension for files which are available in a 32 bit
  66 # and a 64 bit version to simplify shared Makefiles.
  67 # e.g.: obj-y += foo_$(BITS).o
  68 export BITS
  69
  70 #
  71 # Prevent GCC from generating any FP code by mistake.
  72 #
  73 # This must happen before we try the -mpreferred-stack-boundary, see:
  74 #
  75 #    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
  76 #
  77 KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx
  78 KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json
  79 KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
  80
  81 #
  82 # CFLAGS for compiling floating point code inside the kernel.
  83 #
  84 CC_FLAGS_FPU := -msse -msse2
  85 ifdef CONFIG_CC_IS_GCC
  86 # Stack alignment mismatch, proceed with caution.
  87 # GCC < 7.1 cannot compile code using `double` and -mpreferred-stack-boundary=3
  88 # (8B stack alignment).
  89 # See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
  90 #
  91 # The "-msse" in the first argument is there so that the
  92 # -mpreferred-stack-boundary=3 build error:
  93 #
  94 #  -mpreferred-stack-boundary=3 is not between 4 and 12
  95 #
  96 # can be triggered. Otherwise gcc doesn't complain.
  97 CC_FLAGS_FPU += -mhard-float
  98 CC_FLAGS_FPU += $(call cc-option,-msse -mpreferred-stack-boundary=3,-mpreferred-stack-boundary=4)
  99 endif
 100
 101 ifeq ($(CONFIG_X86_KERNEL_IBT),y)
 102 #
 103 # Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate
 104 # NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK
 105 # for jump-tables, as such, disable jump-tables for now.
 106 #
 107 # (jump-tables are implicitly disabled by RETPOLINE)
 108 #
 109 #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
 110 #
 111 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables)
 112 KBUILD_RUSTFLAGS += -Zcf-protection=branch -Zno-jump-tables
 113 else
 114 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
 115 endif
 116
 117 ifeq ($(CONFIG_X86_32),y)
 118         BITS := 32
 119         UTS_MACHINE := i386
 120         CHECKFLAGS += -D__i386__
 121
 122         KBUILD_AFLAGS += -m32
 123         KBUILD_CFLAGS += -m32
 124
 125         KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
 126
 127         # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
 128         # with nonstandard options
 129         KBUILD_CFLAGS += -fno-pic
 130
 131         # Align the stack to the register width instead of using the default
 132         # alignment of 16 bytes. This reduces stack usage and the number of
 133         # alignment instructions.
 134         KBUILD_CFLAGS += $(cc_stack_align4)
 135
 136         # CPU-specific tuning. Anything which can be shared with UML should go here.
 137         include $(srctree)/arch/x86/Makefile_32.cpu
 138         KBUILD_CFLAGS += $(cflags-y)
 139
 140         # temporary until string.h is fixed
 141         KBUILD_CFLAGS += -ffreestanding
 142
 143     ifeq ($(CONFIG_STACKPROTECTOR),y)
 144         ifeq ($(CONFIG_SMP),y)
 145             KBUILD_CFLAGS += -mstack-protector-guard-reg=fs \
 146                              -mstack-protector-guard-symbol=__ref_stack_chk_guard
 147         else
 148             KBUILD_CFLAGS += -mstack-protector-guard=global
 149         endif
 150     endif
 151 else
 152         BITS := 64
 153         UTS_MACHINE := x86_64
 154         CHECKFLAGS += -D__x86_64__
 155
 156         KBUILD_AFLAGS += -m64
 157         KBUILD_CFLAGS += -m64
 158
 159         # Align jump targets to 1 byte, not the default 16 bytes:
 160         KBUILD_CFLAGS += $(call cc-option,-falign-jumps=1)
 161
 162         # Pack loops tightly as well:
 163         KBUILD_CFLAGS += $(call cc-option,-falign-loops=1)
 164
 165         # Don't autogenerate traditional x87 instructions
 166         KBUILD_CFLAGS += -mno-80387
 167         KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
 168
 169         # By default gcc and clang use a stack alignment of 16 bytes for x86.
 170         # However the standard kernel entry on x86-64 leaves the stack on an
 171         # 8-byte boundary. If the compiler isn't informed about the actual
 172         # alignment it will generate extra alignment instructions for the
 173         # default alignment which keep the stack *mis*aligned.
 174         # Furthermore an alignment to the register width reduces stack usage
 175         # and the number of alignment instructions.
 176         KBUILD_CFLAGS += $(cc_stack_align8)
 177
 178         # Use -mskip-rax-setup if supported.
 179         KBUILD_CFLAGS += $(call cc-option,-mskip-rax-setup)
 180
 181         # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
 182         cflags-$(CONFIG_MK8)            += -march=k8
 183         cflags-$(CONFIG_MPSC)           += -march=nocona
 184         cflags-$(CONFIG_MCORE2)         += -march=core2
 185         cflags-$(CONFIG_MATOM)          += -march=atom
 186         cflags-$(CONFIG_GENERIC_CPU)    += -mtune=generic
 187         KBUILD_CFLAGS += $(cflags-y)
 188
 189         rustflags-$(CONFIG_MK8)         += -Ctarget-cpu=k8
 190         rustflags-$(CONFIG_MPSC)        += -Ctarget-cpu=nocona
 191         rustflags-$(CONFIG_MCORE2)      += -Ctarget-cpu=core2
 192         rustflags-$(CONFIG_MATOM)       += -Ctarget-cpu=atom
 193         rustflags-$(CONFIG_GENERIC_CPU) += -Ztune-cpu=generic
 194         KBUILD_RUSTFLAGS += $(rustflags-y)
 195
 196         KBUILD_CFLAGS += -mno-red-zone
 197         KBUILD_CFLAGS += -mcmodel=kernel
 198         KBUILD_RUSTFLAGS += -Cno-redzone=y
 199         KBUILD_RUSTFLAGS += -Ccode-model=kernel
 200 endif
 201
 202 #
 203 # If the function graph tracer is used with mcount instead of fentry,
 204 # '-maccumulate-outgoing-args' is needed to prevent a GCC bug
 205 # (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109)
 206 #
 207 ifdef CONFIG_FUNCTION_GRAPH_TRACER
 208   ifndef CONFIG_HAVE_FENTRY
 209         ACCUMULATE_OUTGOING_ARGS := 1
 210   endif
 211 endif
 212
 213 ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1)
 214         # This compiler flag is not supported by Clang:
 215         KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args,)
 216 endif
 217
 218 # Workaround for a gcc prelease that unfortunately was shipped in a suse release
 219 KBUILD_CFLAGS += -Wno-sign-compare
 220 #
 221 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 222
 223 # Avoid indirect branches in kernel to deal with Spectre
 224 ifdef CONFIG_MITIGATION_RETPOLINE
 225   KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
 226   KBUILD_RUSTFLAGS += $(RETPOLINE_RUSTFLAGS)
 227   # Additionally, avoid generating expensive indirect jumps which
 228   # are subject to retpolines for small number of switch cases.
 229   # LLVM turns off jump table generation by default when under
 230   # retpoline builds, however, gcc does not for x86. This has
 231   # only been fixed starting from gcc stable version 8.4.0 and
 232   # onwards, but not for older ones. See gcc bug #86952.
 233   ifndef CONFIG_CC_IS_CLANG
 234     KBUILD_CFLAGS += -fno-jump-tables
 235   endif
 236 endif
 237
 238 ifdef CONFIG_MITIGATION_SLS
 239   KBUILD_CFLAGS += -mharden-sls=all
 240 endif
 241
 242 ifdef CONFIG_CALL_PADDING
 243 PADDING_CFLAGS := -fpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES)
 244 KBUILD_CFLAGS += $(PADDING_CFLAGS)
 245 export PADDING_CFLAGS
 246
 247 PADDING_RUSTFLAGS := -Zpatchable-function-entry=$(CONFIG_FUNCTION_PADDING_BYTES),$(CONFIG_FUNCTION_PADDING_BYTES)
 248 KBUILD_RUSTFLAGS += $(PADDING_RUSTFLAGS)
 249 export PADDING_RUSTFLAGS
 250 endif
 251
 252 KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)
 253
 254 ifdef CONFIG_X86_NEED_RELOCS
 255 LDFLAGS_vmlinux := --emit-relocs --discard-none
 256 else
 257 LDFLAGS_vmlinux :=
 258 endif
 259
 260 #
 261 # The 64-bit kernel must be aligned to 2MB.  Pass -z max-page-size=0x200000 to
 262 # the linker to force 2MB page size regardless of the default page size used
 263 # by the linker.
 264 #
 265 ifdef CONFIG_X86_64
 266 LDFLAGS_vmlinux += -z max-page-size=0x200000
 267 endif
 268
 269
 270 archscripts: scripts_basic
 271         $(Q)$(MAKE) $(build)=arch/x86/tools relocs
 272
 273 ###
 274 # Syscall table generation
 275
 276 archheaders:
 277         $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all
 278
 279 ###
 280 # Kernel objects
 281
 282 libs-y  += arch/x86/lib/
 283
 284 # drivers-y are linked after core-y
 285 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 286 drivers-$(CONFIG_PCI)            += arch/x86/pci/
 287
 288 # suspend and hibernation support
 289 drivers-$(CONFIG_PM) += arch/x86/power/
 290
 291 drivers-$(CONFIG_VIDEO) += arch/x86/video/
 292
 293 ####
 294 # boot loader support. Several targets are kept for legacy purposes
 295
 296 boot := arch/x86/boot
 297
 298 BOOT_TARGETS = bzdisk fdimage fdimage144 fdimage288 hdimage isoimage
 299
 300 PHONY += bzImage $(BOOT_TARGETS)
 301
 302 # Default kernel to build
 303 all: bzImage
 304
 305 # KBUILD_IMAGE specify target image being built
 306 KBUILD_IMAGE := $(boot)/bzImage
 307
 308 bzImage: vmlinux
 309 ifeq ($(CONFIG_X86_DECODER_SELFTEST),y)
 310         $(Q)$(MAKE) $(build)=arch/x86/tools posttest
 311 endif
 312         $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE)
 313         $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot
 314         $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@
 315
 316 $(BOOT_TARGETS): vmlinux
 317         $(Q)$(MAKE) $(build)=$(boot) $@
 318
 319 PHONY += install
 320 install:
 321         $(call cmd,install)
 322
 323 vdso-install-$(CONFIG_X86_64)           += arch/x86/entry/vdso/vdso64.so.dbg
 324 vdso-install-$(CONFIG_X86_X32_ABI)      += arch/x86/entry/vdso/vdsox32.so.dbg
 325 vdso-install-$(CONFIG_COMPAT_32)        += arch/x86/entry/vdso/vdso32.so.dbg
 326
 327 archprepare: checkbin
 328 checkbin:
 329 ifdef CONFIG_MITIGATION_RETPOLINE
 330 ifeq ($(RETPOLINE_CFLAGS),)
 331         @echo "You are building kernel with non-retpoline compiler." >&2
 332         @echo "Please update your compiler." >&2
 333         @false
 334 endif
 335 endif
 336
 337 ifdef CONFIG_UNWINDER_ORC
 338 orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h
 339 orc_hash_sh := $(srctree)/scripts/orc_hash.sh
 340 targets += $(orc_hash_h)
 341 quiet_cmd_orc_hash = GEN     $@
 342       cmd_orc_hash = mkdir -p $(dir $@); \
 343                      $(CONFIG_SHELL) $(orc_hash_sh) < $< > $@
 344 $(orc_hash_h): $(srctree)/arch/x86/include/asm/orc_types.h $(orc_hash_sh) FORCE
 345         $(call if_changed,orc_hash)
 346 archprepare: $(orc_hash_h)
 347 endif
 348
 349 archclean:
 350         $(Q)rm -rf $(objtree)/arch/i386
 351         $(Q)rm -rf $(objtree)/arch/x86_64
 352
 353 define archhelp
 354   echo  '* bzImage              - Compressed kernel image (arch/x86/boot/bzImage)'
 355   echo  '  install              - Install kernel using (your) ~/bin/$(INSTALLKERNEL) or'
 356   echo  '                         (distribution) /sbin/$(INSTALLKERNEL) or install to '
 357   echo  '                         $$(INSTALL_PATH) and run lilo'
 358   echo  ''
 359   echo  '  fdimage              - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 360   echo  '  fdimage144           - Create 1.4MB boot floppy image (arch/x86/boot/fdimage)'
 361   echo  '  fdimage288           - Create 2.8MB boot floppy image (arch/x86/boot/fdimage)'
 362   echo  '  hdimage              - Create a BIOS/EFI hard disk image (arch/x86/boot/hdimage)'
 363   echo  '  isoimage             - Create a boot CD-ROM image (arch/x86/boot/image.iso)'
 364   echo  '                         bzdisk/fdimage*/hdimage/isoimage also accept:'
 365   echo  '                         FDARGS="..."  arguments for the booted kernel'
 366   echo  '                         FDINITRD=file initrd for the booted kernel'
 367
 368 endef