Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 VERSION = 6
   3 PATCHLEVEL = 7
   4 SUBLEVEL = 0
   5 EXTRAVERSION = -rc1
   6 NAME = Hurr durr I'ma ninja sloth
   7
   8 # *DOCUMENTATION*
   9 # To see a list of typical targets execute "make help"
  10 # More info can be located in ./README
  11 # Comments in this file are targeted only to the developer, do not
  12 # expect to learn how to build the kernel reading this file.
  13
  14 ifeq ($(filter undefine,$(.FEATURES)),)
  15 $(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION))
  16 endif
  17
  18 $(if $(filter __%, $(MAKECMDGOALS)), \
  19         $(error targets prefixed with '__' are only for internal use))
  20
  21 # That's our default target when none is given on the command line
  22 PHONY := __all
  23 __all:
  24
  25 # We are using a recursive build, so we need to do a little thinking
  26 # to get the ordering right.
  27 #
  28 # Most importantly: sub-Makefiles should only ever modify files in
  29 # their own directory. If in some directory we have a dependency on
  30 # a file in another dir (which doesn't happen often, but it's often
  31 # unavoidable when linking the built-in.a targets which finally
  32 # turn into vmlinux), we will call a sub make in that other dir, and
  33 # after that we are sure that everything which is in that other dir
  34 # is now up to date.
  35 #
  36 # The only cases where we need to modify files which have global
  37 # effects are thus separated out and done before the recursive
  38 # descending is started. They are now explicitly listed as the
  39 # prepare rule.
  40
  41 this-makefile := $(lastword $(MAKEFILE_LIST))
  42 export abs_srctree := $(realpath $(dir $(this-makefile)))
  43 export abs_objtree := $(CURDIR)
  44
  45 ifneq ($(sub_make_done),1)
  46
  47 # Do not use make's built-in rules and variables
  48 # (this increases performance and avoids hard-to-debug behaviour)
  49 MAKEFLAGS += -rR
  50
  51 # Avoid funny character set dependencies
  52 unexport LC_ALL
  53 LC_COLLATE=C
  54 LC_NUMERIC=C
  55 export LC_COLLATE LC_NUMERIC
  56
  57 # Avoid interference with shell env settings
  58 unexport GREP_OPTIONS
  59
  60 # Beautify output
  61 # ---------------------------------------------------------------------------
  62 #
  63 # Most of build commands in Kbuild start with "cmd_". You can optionally define
  64 # "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
  65 # that command is printed by default.
  66 #
  67 # e.g.)
  68 #    quiet_cmd_depmod = DEPMOD  $(MODLIB)
  69 #          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
  70 #
  71 # A simple variant is to prefix commands with $(Q) - that's useful
  72 # for commands that shall be hidden in non-verbose mode.
  73 #
  74 #    $(Q)$(MAKE) $(build)=scripts/basic
  75 #
  76 # If KBUILD_VERBOSE contains 1, the whole command is echoed.
  77 # If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
  78 #
  79 # To put more focus on warnings, be less verbose as default
  80 # Use 'make V=1' to see the full commands
  81
  82 ifeq ("$(origin V)", "command line")
  83   KBUILD_VERBOSE = $(V)
  84 endif
  85
  86 quiet = quiet_
  87 Q = @
  88
  89 ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
  90   quiet =
  91   Q =
  92 endif
  93
  94 # If the user is running make -s (silent mode), suppress echoing of
  95 # commands
  96 # make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
  97
  98 ifeq ($(filter 3.%,$(MAKE_VERSION)),)
  99 short-opts := $(firstword -$(MAKEFLAGS))
 100 else
 101 short-opts := $(filter-out --%,$(MAKEFLAGS))
 102 endif
 103
 104 ifneq ($(findstring s,$(short-opts)),)
 105 quiet=silent_
 106 override KBUILD_VERBOSE :=
 107 endif
 108
 109 export quiet Q KBUILD_VERBOSE
 110
 111 # Call a source code checker (by default, "sparse") as part of the
 112 # C compilation.
 113 #
 114 # Use 'make C=1' to enable checking of only re-compiled files.
 115 # Use 'make C=2' to enable checking of *all* source files, regardless
 116 # of whether they are re-compiled or not.
 117 #
 118 # See the file "Documentation/dev-tools/sparse.rst" for more details,
 119 # including where to get the "sparse" utility.
 120
 121 ifeq ("$(origin C)", "command line")
 122   KBUILD_CHECKSRC = $(C)
 123 endif
 124 ifndef KBUILD_CHECKSRC
 125   KBUILD_CHECKSRC = 0
 126 endif
 127
 128 export KBUILD_CHECKSRC
 129
 130 # Enable "clippy" (a linter) as part of the Rust compilation.
 131 #
 132 # Use 'make CLIPPY=1' to enable it.
 133 ifeq ("$(origin CLIPPY)", "command line")
 134   KBUILD_CLIPPY := $(CLIPPY)
 135 endif
 136
 137 export KBUILD_CLIPPY
 138
 139 # Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
 140 # directory of external module to build. Setting M= takes precedence.
 141 ifeq ("$(origin M)", "command line")
 142   KBUILD_EXTMOD := $(M)
 143 endif
 144
 145 $(if $(word 2, $(KBUILD_EXTMOD)), \
 146         $(error building multiple external modules is not supported))
 147
 148 $(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
 149         $(error module directory path cannot contain '$x')))
 150
 151 # Remove trailing slashes
 152 ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
 153 KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
 154 endif
 155
 156 export KBUILD_EXTMOD
 157
 158 # Kbuild will save output files in the current working directory.
 159 # This does not need to match to the root of the kernel source tree.
 160 #
 161 # For example, you can do this:
 162 #
 163 #  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
 164 #
 165 # If you want to save output files in a different location, there are
 166 # two syntaxes to specify it.
 167 #
 168 # 1) O=
 169 # Use "make O=dir/to/store/output/files/"
 170 #
 171 # 2) Set KBUILD_OUTPUT
 172 # Set the environment variable KBUILD_OUTPUT to point to the output directory.
 173 # export KBUILD_OUTPUT=dir/to/store/output/files/; make
 174 #
 175 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 176 # variable.
 177
 178 # Do we want to change the working directory?
 179 ifeq ("$(origin O)", "command line")
 180   KBUILD_OUTPUT := $(O)
 181 endif
 182
 183 ifneq ($(KBUILD_OUTPUT),)
 184 # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
 185 # expand a shell special character '~'. We use a somewhat tedious way here.
 186 abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
 187 $(if $(abs_objtree),, \
 188      $(error failed to create output directory "$(KBUILD_OUTPUT)"))
 189
 190 # $(realpath ...) resolves symlinks
 191 abs_objtree := $(realpath $(abs_objtree))
 192 endif # ifneq ($(KBUILD_OUTPUT),)
 193
 194 ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 195 $(error source directory cannot contain spaces or colons)
 196 endif
 197
 198 ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 199 # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 200 # We need to invoke sub-make to avoid implicit rules in the top Makefile.
 201 need-sub-make := 1
 202 # Cancel implicit rules for this Makefile.
 203 $(this-makefile): ;
 204 endif
 205
 206 export sub_make_done := 1
 207
 208 endif # sub_make_done
 209
 210 ifeq ($(abs_objtree),$(CURDIR))
 211 # Suppress "Entering directory ..." if we are at the final work directory.
 212 no-print-directory := --no-print-directory
 213 else
 214 # Recursion to show "Entering directory ..."
 215 need-sub-make := 1
 216 endif
 217
 218 ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
 219 # If --no-print-directory is unset, recurse once again to set it.
 220 # You may end up recursing into __sub-make twice. This is needed due to the
 221 # behavior change in GNU Make 4.4.1.
 222 need-sub-make := 1
 223 endif
 224
 225 ifeq ($(need-sub-make),1)
 226
 227 PHONY += $(MAKECMDGOALS) __sub-make
 228
 229 $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 230         @:
 231
 232 # Invoke a second make in the output directory, passing relevant variables
 233 __sub-make:
 234         $(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
 235         -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 236
 237 else # need-sub-make
 238
 239 # We process the rest of the Makefile if this is the final invocation of make
 240
 241 ifeq ($(abs_srctree),$(abs_objtree))
 242         # building in the source tree
 243         srctree := .
 244         building_out_of_srctree :=
 245 else
 246         ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 247                 # building in a subdirectory of the source tree
 248                 srctree := ..
 249         else
 250                 srctree := $(abs_srctree)
 251         endif
 252         building_out_of_srctree := 1
 253 endif
 254
 255 ifneq ($(KBUILD_ABS_SRCTREE),)
 256 srctree := $(abs_srctree)
 257 endif
 258
 259 objtree         := .
 260 VPATH           := $(srctree)
 261
 262 export building_out_of_srctree srctree objtree VPATH
 263
 264 # To make sure we do not include .config for any of the *config targets
 265 # catch them early, and hand them over to scripts/kconfig/Makefile
 266 # It is allowed to specify more targets when calling make, including
 267 # mixing *config targets and build targets.
 268 # For example 'make oldconfig all'.
 269 # Detect when mixed targets is specified, and make a second invocation
 270 # of make so .config is not included in this case either (for *config).
 271
 272 version_h := include/generated/uapi/linux/version.h
 273
 274 clean-targets := %clean mrproper cleandocs
 275 no-dot-config-targets := $(clean-targets) \
 276                          cscope gtags TAGS tags help% %docs check% coccicheck \
 277                          $(version_h) headers headers_% archheaders archscripts \
 278                          %asm-generic kernelversion %src-pkg dt_binding_check \
 279                          outputmakefile rustavailable rustfmt rustfmtcheck
 280 no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
 281                           image_name
 282 single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
 283
 284 config-build    :=
 285 mixed-build     :=
 286 need-config     := 1
 287 may-sync-config := 1
 288 single-build    :=
 289
 290 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 291         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 292                 need-config :=
 293         endif
 294 endif
 295
 296 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 297         ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 298                 may-sync-config :=
 299         endif
 300 endif
 301
 302 need-compiler := $(may-sync-config)
 303
 304 ifneq ($(KBUILD_EXTMOD),)
 305         may-sync-config :=
 306 endif
 307
 308 ifeq ($(KBUILD_EXTMOD),)
 309         ifneq ($(filter %config,$(MAKECMDGOALS)),)
 310                 config-build := 1
 311                 ifneq ($(words $(MAKECMDGOALS)),1)
 312                         mixed-build := 1
 313                 endif
 314         endif
 315 endif
 316
 317 # We cannot build single targets and the others at the same time
 318 ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 319         single-build := 1
 320         ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 321                 mixed-build := 1
 322         endif
 323 endif
 324
 325 # For "make -j clean all", "make -j mrproper defconfig all", etc.
 326 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 327         ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 328                 mixed-build := 1
 329         endif
 330 endif
 331
 332 # install and modules_install need also be processed one by one
 333 ifneq ($(filter install,$(MAKECMDGOALS)),)
 334         ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 335                 mixed-build := 1
 336         endif
 337 endif
 338
 339 ifdef mixed-build
 340 # ===========================================================================
 341 # We're called with mixed targets (*config and build targets).
 342 # Handle them one by one.
 343
 344 PHONY += $(MAKECMDGOALS) __build_one_by_one
 345
 346 $(MAKECMDGOALS): __build_one_by_one
 347         @:
 348
 349 __build_one_by_one:
 350         $(Q)set -e; \
 351         for i in $(MAKECMDGOALS); do \
 352                 $(MAKE) -f $(srctree)/Makefile $$i; \
 353         done
 354
 355 else # !mixed-build
 356
 357 include $(srctree)/scripts/Kbuild.include
 358
 359 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 360 KERNELRELEASE = $(call read-file, include/config/kernel.release)
 361 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 362 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 363
 364 include $(srctree)/scripts/subarch.include
 365
 366 # Cross compiling and selecting different set of gcc/bin-utils
 367 # ---------------------------------------------------------------------------
 368 #
 369 # When performing cross compilation for other architectures ARCH shall be set
 370 # to the target architecture. (See arch/* for the possibilities).
 371 # ARCH can be set during invocation of make:
 372 # make ARCH=arm64
 373 # Another way is to have ARCH set in the environment.
 374 # The default ARCH is the host where make is executed.
 375
 376 # CROSS_COMPILE specify the prefix used for all executables used
 377 # during compilation. Only gcc and related bin-utils executables
 378 # are prefixed with $(CROSS_COMPILE).
 379 # CROSS_COMPILE can be set on the command line
 380 # make CROSS_COMPILE=aarch64-linux-gnu-
 381 # Alternatively CROSS_COMPILE can be set in the environment.
 382 # Default value for CROSS_COMPILE is not to prefix executables
 383 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 384 ARCH            ?= $(SUBARCH)
 385
 386 # Architecture as present in compile.h
 387 UTS_MACHINE     := $(ARCH)
 388 SRCARCH         := $(ARCH)
 389
 390 # Additional ARCH settings for x86
 391 ifeq ($(ARCH),i386)
 392         SRCARCH := x86
 393 endif
 394 ifeq ($(ARCH),x86_64)
 395         SRCARCH := x86
 396 endif
 397
 398 # Additional ARCH settings for sparc
 399 ifeq ($(ARCH),sparc32)
 400        SRCARCH := sparc
 401 endif
 402 ifeq ($(ARCH),sparc64)
 403        SRCARCH := sparc
 404 endif
 405
 406 # Additional ARCH settings for parisc
 407 ifeq ($(ARCH),parisc64)
 408        SRCARCH := parisc
 409 endif
 410
 411 export cross_compiling :=
 412 ifneq ($(SRCARCH),$(SUBARCH))
 413 cross_compiling := 1
 414 endif
 415
 416 KCONFIG_CONFIG  ?= .config
 417 export KCONFIG_CONFIG
 418
 419 # SHELL used by kbuild
 420 CONFIG_SHELL := sh
 421
 422 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 423 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 424 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 425
 426 ifneq ($(LLVM),)
 427 ifneq ($(filter %/,$(LLVM)),)
 428 LLVM_PREFIX := $(LLVM)
 429 else ifneq ($(filter -%,$(LLVM)),)
 430 LLVM_SUFFIX := $(LLVM)
 431 endif
 432
 433 HOSTCC  = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
 434 HOSTCXX = $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
 435 else
 436 HOSTCC  = gcc
 437 HOSTCXX = g++
 438 endif
 439 HOSTRUSTC = rustc
 440 HOSTPKG_CONFIG  = pkg-config
 441
 442 KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 443                          -O2 -fomit-frame-pointer -std=gnu11
 444 KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
 445 KBUILD_USERLDFLAGS := $(USERLDFLAGS)
 446
 447 # These flags apply to all Rust code in the tree, including the kernel and
 448 # host programs.
 449 export rust_common_flags := --edition=2021 \
 450                             -Zbinary_dep_depinfo=y \
 451                             -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
 452                             -Dunreachable_pub -Dnon_ascii_idents \
 453                             -Wmissing_docs \
 454                             -Drustdoc::missing_crate_level_docs \
 455                             -Dclippy::correctness -Dclippy::style \
 456                             -Dclippy::suspicious -Dclippy::complexity \
 457                             -Dclippy::perf \
 458                             -Dclippy::let_unit_value -Dclippy::mut_mut \
 459                             -Dclippy::needless_bitwise_bool \
 460                             -Dclippy::needless_continue \
 461                             -Dclippy::no_mangle_with_rust_abi \
 462                             -Wclippy::dbg_macro
 463
 464 KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 465 KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 466 KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
 467                         -Zallow-features= $(HOSTRUSTFLAGS)
 468 KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 469 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 470
 471 # Make variables (CC, etc...)
 472 CPP             = $(CC) -E
 473 ifneq ($(LLVM),)
 474 CC              = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
 475 LD              = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
 476 AR              = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
 477 NM              = $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
 478 OBJCOPY         = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
 479 OBJDUMP         = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
 480 READELF         = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
 481 STRIP           = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
 482 else
 483 CC              = $(CROSS_COMPILE)gcc
 484 LD              = $(CROSS_COMPILE)ld
 485 AR              = $(CROSS_COMPILE)ar
 486 NM              = $(CROSS_COMPILE)nm
 487 OBJCOPY         = $(CROSS_COMPILE)objcopy
 488 OBJDUMP         = $(CROSS_COMPILE)objdump
 489 READELF         = $(CROSS_COMPILE)readelf
 490 STRIP           = $(CROSS_COMPILE)strip
 491 endif
 492 RUSTC           = rustc
 493 RUSTDOC         = rustdoc
 494 RUSTFMT         = rustfmt
 495 CLIPPY_DRIVER   = clippy-driver
 496 BINDGEN         = bindgen
 497 CARGO           = cargo
 498 PAHOLE          = pahole
 499 RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 500 LEX             = flex
 501 YACC            = bison
 502 AWK             = awk
 503 INSTALLKERNEL  := installkernel
 504 PERL            = perl
 505 PYTHON3         = python3
 506 CHECK           = sparse
 507 BASH            = bash
 508 KGZIP           = gzip
 509 KBZIP2          = bzip2
 510 KLZOP           = lzop
 511 LZMA            = lzma
 512 LZ4             = lz4c
 513 XZ              = xz
 514 ZSTD            = zstd
 515
 516 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 517                   -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 518 NOSTDINC_FLAGS :=
 519 CFLAGS_MODULE   =
 520 RUSTFLAGS_MODULE =
 521 AFLAGS_MODULE   =
 522 LDFLAGS_MODULE  =
 523 CFLAGS_KERNEL   =
 524 RUSTFLAGS_KERNEL =
 525 AFLAGS_KERNEL   =
 526 LDFLAGS_vmlinux =
 527
 528 # Use USERINCLUDE when you must reference the UAPI directories only.
 529 USERINCLUDE    := \
 530                 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 531                 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 532                 -I$(srctree)/include/uapi \
 533                 -I$(objtree)/include/generated/uapi \
 534                 -include $(srctree)/include/linux/compiler-version.h \
 535                 -include $(srctree)/include/linux/kconfig.h
 536
 537 # Use LINUXINCLUDE when you must reference the include/ directory.
 538 # Needed to be compatible with the O= option
 539 LINUXINCLUDE    := \
 540                 -I$(srctree)/arch/$(SRCARCH)/include \
 541                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
 542                 $(if $(building_out_of_srctree),-I$(srctree)/include) \
 543                 -I$(objtree)/include \
 544                 $(USERINCLUDE)
 545
 546 KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 547
 548 KBUILD_CFLAGS :=
 549 KBUILD_CFLAGS += -std=gnu11
 550 KBUILD_CFLAGS += -fshort-wchar
 551 KBUILD_CFLAGS += -funsigned-char
 552 KBUILD_CFLAGS += -fno-common
 553 KBUILD_CFLAGS += -fno-PIE
 554 KBUILD_CFLAGS += -fno-strict-aliasing
 555
 556 KBUILD_CPPFLAGS := -D__KERNEL__
 557 KBUILD_RUSTFLAGS := $(rust_common_flags) \
 558                     --target=$(objtree)/scripts/target.json \
 559                     -Cpanic=abort -Cembed-bitcode=n -Clto=n \
 560                     -Cforce-unwind-tables=n -Ccodegen-units=1 \
 561                     -Csymbol-mangling-version=v0 \
 562                     -Crelocation-model=static \
 563                     -Zfunction-sections=n \
 564                     -Dclippy::float_arithmetic
 565
 566 KBUILD_AFLAGS_KERNEL :=
 567 KBUILD_CFLAGS_KERNEL :=
 568 KBUILD_RUSTFLAGS_KERNEL :=
 569 KBUILD_AFLAGS_MODULE  := -DMODULE
 570 KBUILD_CFLAGS_MODULE  := -DMODULE
 571 KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
 572 KBUILD_LDFLAGS_MODULE :=
 573 KBUILD_LDFLAGS :=
 574 CLANG_FLAGS :=
 575
 576 ifeq ($(KBUILD_CLIPPY),1)
 577         RUSTC_OR_CLIPPY_QUIET := CLIPPY
 578         RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
 579 else
 580         RUSTC_OR_CLIPPY_QUIET := RUSTC
 581         RUSTC_OR_CLIPPY = $(RUSTC)
 582 endif
 583
 584 ifdef RUST_LIB_SRC
 585         export RUST_LIB_SRC
 586 endif
 587
 588 # Allows the usage of unstable features in stable compilers.
 589 export RUSTC_BOOTSTRAP := 1
 590
 591 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
 592 export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
 593 export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
 594 export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 595 export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 596 export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 597 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 598 export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
 599
 600 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 601 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 602 export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
 603 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 604 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 605 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
 606
 607 # Files to ignore in find ... statements
 608
 609 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 610                           -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 611                           -prune -o
 612 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 613                          --exclude CVS --exclude .pc --exclude .hg --exclude .git
 614
 615 # ===========================================================================
 616 # Rules shared between *config targets and build targets
 617
 618 # Basic helpers built in scripts/basic/
 619 PHONY += scripts_basic
 620 scripts_basic:
 621         $(Q)$(MAKE) $(build)=scripts/basic
 622
 623 PHONY += outputmakefile
 624 ifdef building_out_of_srctree
 625 # Before starting out-of-tree build, make sure the source tree is clean.
 626 # outputmakefile generates a Makefile in the output directory, if using a
 627 # separate output directory. This allows convenient use of make in the
 628 # output directory.
 629 # At the same time when output Makefile generated, generate .gitignore to
 630 # ignore whole output directory
 631
 632 quiet_cmd_makefile = GEN     Makefile
 633       cmd_makefile = { \
 634         echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
 635         echo "include $(srctree)/Makefile"; \
 636         } > Makefile
 637
 638 outputmakefile:
 639         @if [ -f $(srctree)/.config -o \
 640                  -d $(srctree)/include/config -o \
 641                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 642                 echo >&2 "***"; \
 643                 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 644                 echo >&2 "*** in $(abs_srctree)";\
 645                 echo >&2 "***"; \
 646                 false; \
 647         fi
 648         $(Q)ln -fsn $(srctree) source
 649         $(call cmd,makefile)
 650         $(Q)test -e .gitignore || \
 651         { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 652 endif
 653
 654 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 655 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 656 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 657 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
 658 CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
 659
 660 ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 661 include $(srctree)/scripts/Makefile.clang
 662 endif
 663
 664 # Include this also for config targets because some architectures need
 665 # cc-cross-prefix to determine CROSS_COMPILE.
 666 ifdef need-compiler
 667 include $(srctree)/scripts/Makefile.compiler
 668 endif
 669
 670 ifdef config-build
 671 # ===========================================================================
 672 # *config targets only - make sure prerequisites are updated, and descend
 673 # in scripts/kconfig to make the *config target
 674
 675 # Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
 676 # KBUILD_DEFCONFIG may point out an alternative default configuration
 677 # used for 'make defconfig'
 678 include $(srctree)/arch/$(SRCARCH)/Makefile
 679 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 680
 681 config: outputmakefile scripts_basic FORCE
 682         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 683
 684 %config: outputmakefile scripts_basic FORCE
 685         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 686
 687 else #!config-build
 688 # ===========================================================================
 689 # Build targets only - this includes vmlinux, arch-specific targets, clean
 690 # targets and others. In general all targets except *config targets.
 691
 692 # If building an external module we do not care about the all: rule
 693 # but instead __all depend on modules
 694 PHONY += all
 695 ifeq ($(KBUILD_EXTMOD),)
 696 __all: all
 697 else
 698 __all: modules
 699 endif
 700
 701 targets :=
 702
 703 # Decide whether to build built-in, modular, or both.
 704 # Normally, just do built-in.
 705
 706 KBUILD_MODULES :=
 707 KBUILD_BUILTIN := 1
 708
 709 # If we have only "make modules", don't compile built-in objects.
 710 ifeq ($(MAKECMDGOALS),modules)
 711   KBUILD_BUILTIN :=
 712 endif
 713
 714 # If we have "make <whatever> modules", compile modules
 715 # in addition to whatever we do anyway.
 716 # Just "make" or "make all" shall build modules as well
 717
 718 ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 719   KBUILD_MODULES := 1
 720 endif
 721
 722 ifeq ($(MAKECMDGOALS),)
 723   KBUILD_MODULES := 1
 724 endif
 725
 726 export KBUILD_MODULES KBUILD_BUILTIN
 727
 728 ifdef need-config
 729 include include/config/auto.conf
 730 endif
 731
 732 ifeq ($(KBUILD_EXTMOD),)
 733 # Objects we will link into vmlinux / subdirs we need to visit
 734 core-y          :=
 735 drivers-y       :=
 736 libs-y          := lib/
 737 endif # KBUILD_EXTMOD
 738
 739 # The all: target is the default when no target is given on the
 740 # command line.
 741 # This allow a user to issue only 'make' to build a kernel including modules
 742 # Defaults to vmlinux, but the arch makefile usually adds further targets
 743 all: vmlinux
 744
 745 CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage
 746 ifdef CONFIG_CC_IS_GCC
 747 CFLAGS_GCOV     += -fno-tree-loop-im
 748 endif
 749 export CFLAGS_GCOV
 750
 751 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 752 ifdef CONFIG_FUNCTION_TRACER
 753   CC_FLAGS_FTRACE := -pg
 754 endif
 755
 756 include $(srctree)/arch/$(SRCARCH)/Makefile
 757
 758 ifdef need-config
 759 ifdef may-sync-config
 760 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 761 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 762 # because some architectures define CROSS_COMPILE there.
 763 include include/config/auto.conf.cmd
 764
 765 $(KCONFIG_CONFIG):
 766         @echo >&2 '***'
 767         @echo >&2 '*** Configuration file "$@" not found!'
 768         @echo >&2 '***'
 769         @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 770         @echo >&2 '*** "make menuconfig" or "make xconfig").'
 771         @echo >&2 '***'
 772         @/bin/false
 773
 774 # The actual configuration files used during the build are stored in
 775 # include/generated/ and include/config/. Update them if .config is newer than
 776 # include/config/auto.conf (which mirrors .config).
 777 #
 778 # This exploits the 'multi-target pattern rule' trick.
 779 # The syncconfig should be executed only once to make all the targets.
 780 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 781 #
 782 # Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 783 # so you cannot notice that Kconfig is waiting for the user input.
 784 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
 785         $(Q)$(kecho) "  SYNC    $@"
 786         $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 787 else # !may-sync-config
 788 # External modules and some install targets need include/generated/autoconf.h
 789 # and include/config/auto.conf but do not care if they are up-to-date.
 790 # Use auto.conf to trigger the test
 791 PHONY += include/config/auto.conf
 792
 793 include/config/auto.conf:
 794         @test -e include/generated/autoconf.h -a -e $@ || (             \
 795         echo >&2;                                                       \
 796         echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 797         echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 798         echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 799         echo >&2 ;                                                      \
 800         /bin/false)
 801
 802 endif # may-sync-config
 803 endif # need-config
 804
 805 KBUILD_CFLAGS   += -fno-delete-null-pointer-checks
 806
 807 ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 808 KBUILD_CFLAGS += -O2
 809 KBUILD_RUSTFLAGS += -Copt-level=2
 810 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 811 KBUILD_CFLAGS += -Os
 812 KBUILD_RUSTFLAGS += -Copt-level=s
 813 endif
 814
 815 # Always set `debug-assertions` and `overflow-checks` because their default
 816 # depends on `opt-level` and `debug-assertions`, respectively.
 817 KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
 818 KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
 819
 820 # Tell gcc to never replace conditional load with a non-conditional one
 821 ifdef CONFIG_CC_IS_GCC
 822 # gcc-10 renamed --param=allow-store-data-races=0 to
 823 # -fno-allow-store-data-races.
 824 KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 825 KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 826 endif
 827
 828 ifdef CONFIG_READABLE_ASM
 829 # Disable optimizations that make assembler listings hard to read.
 830 # reorder blocks reorders the control in the function
 831 # ipa clone creates specialized cloned functions
 832 # partial inlining inlines only parts of functions
 833 KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
 834 endif
 835
 836 stackp-flags-y                                    := -fno-stack-protector
 837 stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 838 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 839
 840 KBUILD_CFLAGS += $(stackp-flags-y)
 841
 842 KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
 843 KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
 844
 845 ifdef CONFIG_FRAME_POINTER
 846 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 847 KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
 848 else
 849 # Some targets (ARM with Thumb2, for example), can't be built with frame
 850 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 851 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 852 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 853 # -fomit-frame-pointer with FUNCTION_TRACER.
 854 # In the Rust target specification, "frame-pointer" is set explicitly
 855 # to "may-omit".
 856 ifndef CONFIG_FUNCTION_TRACER
 857 KBUILD_CFLAGS   += -fomit-frame-pointer
 858 endif
 859 endif
 860
 861 # Initialize all stack variables with a 0xAA pattern.
 862 ifdef CONFIG_INIT_STACK_ALL_PATTERN
 863 KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 864 endif
 865
 866 # Initialize all stack variables with a zero value.
 867 ifdef CONFIG_INIT_STACK_ALL_ZERO
 868 KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 869 ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
 870 # https://github.com/llvm/llvm-project/issues/44842
 871 CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 872 export CC_AUTO_VAR_INIT_ZERO_ENABLER
 873 KBUILD_CFLAGS   += $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
 874 endif
 875 endif
 876
 877 # While VLAs have been removed, GCC produces unreachable stack probes
 878 # for the randomize_kstack_offset feature. Disable it for all compilers.
 879 KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 880
 881 # Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
 882 ifdef CONFIG_ZERO_CALL_USED_REGS
 883 KBUILD_CFLAGS   += -fzero-call-used-regs=used-gpr
 884 endif
 885
 886 ifdef CONFIG_FUNCTION_TRACER
 887 ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 888   CC_FLAGS_FTRACE       += -mrecord-mcount
 889   ifdef CONFIG_HAVE_NOP_MCOUNT
 890     ifeq ($(call cc-option-yn, -mnop-mcount),y)
 891       CC_FLAGS_FTRACE   += -mnop-mcount
 892       CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 893     endif
 894   endif
 895 endif
 896 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 897   ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
 898     CC_FLAGS_USING      += -DCC_USING_NOP_MCOUNT
 899   endif
 900 endif
 901 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 902   ifdef CONFIG_HAVE_C_RECORDMCOUNT
 903     BUILD_C_RECORDMCOUNT := y
 904     export BUILD_C_RECORDMCOUNT
 905   endif
 906 endif
 907 ifdef CONFIG_HAVE_FENTRY
 908   # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
 909   ifeq ($(call cc-option-yn, -mfentry),y)
 910     CC_FLAGS_FTRACE     += -mfentry
 911     CC_FLAGS_USING      += -DCC_USING_FENTRY
 912   endif
 913 endif
 914 export CC_FLAGS_FTRACE
 915 KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 916 KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 917 endif
 918
 919 # We trigger additional mismatches with less inlining
 920 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 921 KBUILD_CFLAGS += -fno-inline-functions-called-once
 922 endif
 923
 924 # `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
 925 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 926 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 927 KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
 928 LDFLAGS_vmlinux += --gc-sections
 929 endif
 930
 931 ifdef CONFIG_SHADOW_CALL_STACK
 932 ifndef CONFIG_DYNAMIC_SCS
 933 CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 934 KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 935 endif
 936 export CC_FLAGS_SCS
 937 endif
 938
 939 ifdef CONFIG_LTO_CLANG
 940 ifdef CONFIG_LTO_CLANG_THIN
 941 CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 942 KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 943 else
 944 CC_FLAGS_LTO    := -flto
 945 endif
 946 CC_FLAGS_LTO    += -fvisibility=hidden
 947
 948 # Limit inlining across translation units to reduce binary size
 949 KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 950
 951 # Check for frame size exceeding threshold during prolog/epilog insertion
 952 # when using lld < 13.0.0.
 953 ifneq ($(CONFIG_FRAME_WARN),0)
 954 ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
 955 KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 956 endif
 957 endif
 958 endif
 959
 960 ifdef CONFIG_LTO
 961 KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 962 KBUILD_AFLAGS   += -fno-lto
 963 export CC_FLAGS_LTO
 964 endif
 965
 966 ifdef CONFIG_CFI_CLANG
 967 CC_FLAGS_CFI    := -fsanitize=kcfi
 968 KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 969 export CC_FLAGS_CFI
 970 endif
 971
 972 ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
 973 KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
 974 endif
 975
 976 # arch Makefile may override CC so keep this after arch Makefile is included
 977 NOSTDINC_FLAGS += -nostdinc
 978
 979 # To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
 980 # the kernel uses only C99 flexible arrays for dynamically sized trailing
 981 # arrays. Enforce this for everything that may examine structure sizes and
 982 # perform bounds checking.
 983 KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
 984
 985 # disable invalid "can't wrap" optimizations for signed / pointers
 986 KBUILD_CFLAGS   += -fno-strict-overflow
 987
 988 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
 989 KBUILD_CFLAGS  += -fno-stack-check
 990
 991 # conserve stack if available
 992 ifdef CONFIG_CC_IS_GCC
 993 KBUILD_CFLAGS   += -fconserve-stack
 994 endif
 995
 996 # change __FILE__ to the relative path from the srctree
 997 KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
 998
 999 # include additional Makefiles when needed
1000 include-y                       := scripts/Makefile.extrawarn
1001 include-$(CONFIG_DEBUG_INFO)    += scripts/Makefile.debug
1002 include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1003 include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1004 include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1005 include-$(CONFIG_KMSAN)         += scripts/Makefile.kmsan
1006 include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1007 include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1008 include-$(CONFIG_RANDSTRUCT)    += scripts/Makefile.randstruct
1009 include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1010
1011 include $(addprefix $(srctree)/, $(include-y))
1012
1013 # scripts/Makefile.gcc-plugins is intentionally included last.
1014 # Do not add $(call cc-option,...) below this line. When you build the kernel
1015 # from the clean source tree, the GCC plugins do not exist at this point.
1016
1017 # Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1018 KBUILD_CPPFLAGS += $(KCPPFLAGS)
1019 KBUILD_AFLAGS   += $(KAFLAGS)
1020 KBUILD_CFLAGS   += $(KCFLAGS)
1021 KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1022
1023 KBUILD_LDFLAGS_MODULE += --build-id=sha1
1024 LDFLAGS_vmlinux += --build-id=sha1
1025
1026 KBUILD_LDFLAGS  += -z noexecstack
1027 ifeq ($(CONFIG_LD_IS_BFD),y)
1028 KBUILD_LDFLAGS  += $(call ld-option,--no-warn-rwx-segments)
1029 endif
1030
1031 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1032 LDFLAGS_vmlinux += -X
1033 endif
1034
1035 ifeq ($(CONFIG_RELR),y)
1036 # ld.lld before 15 did not support -z pack-relative-relocs.
1037 LDFLAGS_vmlinux += $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1038 endif
1039
1040 # We never want expected sections to be placed heuristically by the
1041 # linker. All sections should be explicitly named in the linker script.
1042 ifdef CONFIG_LD_ORPHAN_WARN
1043 LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1044 endif
1045
1046 # Align the bit size of userspace programs with the kernel
1047 KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1048 KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1049
1050 # make the checker run with the right architecture
1051 CHECKFLAGS += --arch=$(ARCH)
1052
1053 # insure the checker run with the right endianness
1054 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1055
1056 # the checker needs the correct machine size
1057 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1058
1059 # Default kernel image to build when no specific target is given.
1060 # KBUILD_IMAGE may be overruled on the command line or
1061 # set in the environment
1062 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
1063 # this default value
1064 export KBUILD_IMAGE ?= vmlinux
1065
1066 #
1067 # INSTALL_PATH specifies where to place the updated kernel and system map
1068 # images. Default is /boot, but you can set it to other values
1069 export  INSTALL_PATH ?= /boot
1070
1071 #
1072 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1073 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1074 # an argument if needed. Otherwise it defaults to the kernel install path
1075 #
1076 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1077
1078 #
1079 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1080 # relocations required by build roots.  This is not defined in the
1081 # makefile but the argument can be passed to make if needed.
1082 #
1083
1084 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1085 export MODLIB
1086
1087 PHONY += prepare0
1088
1089 export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1090 export MODORDER := $(extmod_prefix)modules.order
1091 export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1092
1093 ifeq ($(KBUILD_EXTMOD),)
1094
1095 build-dir       := .
1096 clean-dirs      := $(sort . Documentation \
1097                      $(patsubst %/,%,$(filter %/, $(core-) \
1098                         $(drivers-) $(libs-))))
1099
1100 export ARCH_CORE        := $(core-y)
1101 export ARCH_LIB         := $(filter %/, $(libs-y))
1102 export ARCH_DRIVERS     := $(drivers-y) $(drivers-m)
1103 # Externally visible symbols (used by link-vmlinux.sh)
1104
1105 KBUILD_VMLINUX_OBJS := ./built-in.a
1106 ifdef CONFIG_MODULES
1107 KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1108 KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1109 else
1110 KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1111 endif
1112
1113 export KBUILD_VMLINUX_LIBS
1114 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1115
1116 ifdef CONFIG_TRIM_UNUSED_KSYMS
1117 # For the kernel to actually contain only the needed exported symbols,
1118 # we have to build modules as well to determine what those symbols are.
1119 KBUILD_MODULES := 1
1120 endif
1121
1122 # '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1123 quiet_cmd_ar_vmlinux.a = AR      $@
1124       cmd_ar_vmlinux.a = \
1125         rm -f $@; \
1126         $(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1127         $(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1128
1129 targets += vmlinux.a
1130 vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1131         $(call if_changed,ar_vmlinux.a)
1132
1133 PHONY += vmlinux_o
1134 vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1135         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1136
1137 vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1138         @:
1139
1140 PHONY += vmlinux
1141 # LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1142 # not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1143 # unrelated; the decompressors just happen to have the same base name,
1144 # arch/*/boot/compressed/vmlinux.
1145 # Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1146 #
1147 # _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1148 #   https://savannah.gnu.org/bugs/?61463
1149 # For Make > 4.4, the following simple code will work:
1150 #  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1151 vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1152 vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1153 vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1154         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1155
1156 # The actual objects are generated when descending,
1157 # make sure no implicit rule kicks in
1158 $(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1159
1160 ifeq ($(origin KERNELRELEASE),file)
1161 filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1162 else
1163 filechk_kernel.release = echo $(KERNELRELEASE)
1164 endif
1165
1166 # Store (new) KERNELRELEASE string in include/config/kernel.release
1167 include/config/kernel.release: FORCE
1168         $(call filechk,kernel.release)
1169
1170 # Additional helpers built in scripts/
1171 # Carefully list dependencies so we do not try to build scripts twice
1172 # in parallel
1173 PHONY += scripts
1174 scripts: scripts_basic scripts_dtc
1175         $(Q)$(MAKE) $(build)=$(@)
1176
1177 # Things we need to do before we recursively start building the kernel
1178 # or the modules are listed in "prepare".
1179 # A multi level approach is used. prepareN is processed before prepareN-1.
1180 # archprepare is used in arch Makefiles and when processed asm symlink,
1181 # version.h and scripts_basic is processed / created.
1182
1183 PHONY += prepare archprepare
1184
1185 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1186         asm-generic $(version_h) include/generated/utsrelease.h \
1187         include/generated/compile.h include/generated/autoconf.h remove-stale-files
1188
1189 prepare0: archprepare
1190         $(Q)$(MAKE) $(build)=scripts/mod
1191         $(Q)$(MAKE) $(build)=. prepare
1192
1193 # All the preparing..
1194 prepare: prepare0
1195 ifdef CONFIG_RUST
1196         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1197         $(Q)$(MAKE) $(build)=rust
1198 endif
1199
1200 PHONY += remove-stale-files
1201 remove-stale-files:
1202         $(Q)$(srctree)/scripts/remove-stale-files
1203
1204 # Support for using generic headers in asm-generic
1205 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1206
1207 PHONY += asm-generic uapi-asm-generic
1208 asm-generic: uapi-asm-generic
1209         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1210         generic=include/asm-generic
1211 uapi-asm-generic:
1212         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1213         generic=include/uapi/asm-generic
1214
1215 # Generate some files
1216 # ---------------------------------------------------------------------------
1217
1218 # KERNELRELEASE can change from a few different places, meaning version.h
1219 # needs to be updated, so this check is forced on all builds
1220
1221 uts_len := 64
1222 define filechk_utsrelease.h
1223         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1224           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1225           exit 1;                                                         \
1226         fi;                                                               \
1227         echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1228 endef
1229
1230 define filechk_version.h
1231         if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1232                 echo \#define LINUX_VERSION_CODE $(shell                 \
1233                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1234         else                                                             \
1235                 echo \#define LINUX_VERSION_CODE $(shell                 \
1236                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1237         fi;                                                              \
1238         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1239         ((c) > 255 ? 255 : (c)))';                                       \
1240         echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1241         echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1242         echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1243 endef
1244
1245 $(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1246 $(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1247 $(version_h): FORCE
1248         $(call filechk,version.h)
1249
1250 include/generated/utsrelease.h: include/config/kernel.release FORCE
1251         $(call filechk,utsrelease.h)
1252
1253 filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1254         "$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1255
1256 include/generated/compile.h: FORCE
1257         $(call filechk,compile.h)
1258
1259 PHONY += headerdep
1260 headerdep:
1261         $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1262         $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1263
1264 # ---------------------------------------------------------------------------
1265 # Kernel headers
1266
1267 #Default location for installed headers
1268 export INSTALL_HDR_PATH = $(objtree)/usr
1269
1270 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1271       cmd_headers_install = \
1272         mkdir -p $(INSTALL_HDR_PATH); \
1273         rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1274         usr/include $(INSTALL_HDR_PATH)
1275
1276 PHONY += headers_install
1277 headers_install: headers
1278         $(call cmd,headers_install)
1279
1280 PHONY += archheaders archscripts
1281
1282 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1283
1284 PHONY += headers
1285 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1286         $(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1287         $(Q)$(MAKE) $(hdr-inst)=include/uapi
1288         $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1289
1290 ifdef CONFIG_HEADERS_INSTALL
1291 prepare: headers
1292 endif
1293
1294 PHONY += scripts_unifdef
1295 scripts_unifdef: scripts_basic
1296         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1297
1298 # ---------------------------------------------------------------------------
1299 # Install
1300
1301 # Many distributions have the custom install script, /sbin/installkernel.
1302 # If DKMS is installed, 'make install' will eventually recurse back
1303 # to this Makefile to build and install external modules.
1304 # Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1305
1306 quiet_cmd_install = INSTALL $(INSTALL_PATH)
1307       cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1308
1309 # ---------------------------------------------------------------------------
1310 # vDSO install
1311
1312 PHONY += vdso_install
1313 vdso_install: export INSTALL_FILES = $(vdso-install-y)
1314 vdso_install:
1315         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1316
1317 # ---------------------------------------------------------------------------
1318 # Tools
1319
1320 ifdef CONFIG_OBJTOOL
1321 prepare: tools/objtool
1322 endif
1323
1324 ifdef CONFIG_BPF
1325 ifdef CONFIG_DEBUG_INFO_BTF
1326 prepare: tools/bpf/resolve_btfids
1327 endif
1328 endif
1329
1330 PHONY += resolve_btfids_clean
1331
1332 resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1333
1334 # tools/bpf/resolve_btfids directory might not exist
1335 # in output directory, skip its clean in that case
1336 resolve_btfids_clean:
1337 ifneq ($(wildcard $(resolve_btfids_O)),)
1338         $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1339 endif
1340
1341 # Clear a bunch of variables before executing the submake
1342 ifeq ($(quiet),silent_)
1343 tools_silent=s
1344 endif
1345
1346 tools/: FORCE
1347         $(Q)mkdir -p $(objtree)/tools
1348         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1349
1350 tools/%: FORCE
1351         $(Q)mkdir -p $(objtree)/tools
1352         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1353
1354 # ---------------------------------------------------------------------------
1355 # Kernel selftest
1356
1357 PHONY += kselftest
1358 kselftest: headers
1359         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1360
1361 kselftest-%: headers FORCE
1362         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1363
1364 PHONY += kselftest-merge
1365 kselftest-merge:
1366         $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1367         $(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1368                 xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1369         $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1370
1371 # ---------------------------------------------------------------------------
1372 # Devicetree files
1373
1374 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1375 dtstree := arch/$(SRCARCH)/boot/dts
1376 endif
1377
1378 ifneq ($(dtstree),)
1379
1380 %.dtb: dtbs_prepare
1381         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1382
1383 %.dtbo: dtbs_prepare
1384         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1385
1386 PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1387 dtbs: dtbs_prepare
1388         $(Q)$(MAKE) $(build)=$(dtstree)
1389
1390 # include/config/kernel.release is actually needed when installing DTBs because
1391 # INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1392 # dtbs_install depend on it as dtbs_install may run as root.
1393 dtbs_prepare: include/config/kernel.release scripts_dtc
1394
1395 ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1396 export CHECK_DTBS=y
1397 endif
1398
1399 ifneq ($(CHECK_DTBS),)
1400 dtbs_prepare: dt_binding_check
1401 endif
1402
1403 dtbs_check: dtbs
1404
1405 dtbs_install:
1406         $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1407
1408 ifdef CONFIG_OF_EARLY_FLATTREE
1409 all: dtbs
1410 endif
1411
1412 endif
1413
1414 PHONY += scripts_dtc
1415 scripts_dtc: scripts_basic
1416         $(Q)$(MAKE) $(build)=scripts/dtc
1417
1418 ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1419 export CHECK_DT_BINDING=y
1420 endif
1421
1422 PHONY += dt_binding_check
1423 dt_binding_check: scripts_dtc
1424         $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1425
1426 PHONY += dt_compatible_check
1427 dt_compatible_check: dt_binding_check
1428         $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1429
1430 # ---------------------------------------------------------------------------
1431 # Modules
1432
1433 ifdef CONFIG_MODULES
1434
1435 # By default, build modules as well
1436
1437 all: modules
1438
1439 # When we're building modules with modversions, we need to consider
1440 # the built-in objects during the descend as well, in order to
1441 # make sure the checksums are up to date before we record them.
1442 ifdef CONFIG_MODVERSIONS
1443   KBUILD_BUILTIN := 1
1444 endif
1445
1446 # Build modules
1447 #
1448
1449 # *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1450 # is an exception.
1451 ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1452 KBUILD_BUILTIN := 1
1453 modules: vmlinux
1454 endif
1455
1456 modules: modules_prepare
1457
1458 # Target to prepare building external modules
1459 modules_prepare: prepare
1460         $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1461
1462 endif # CONFIG_MODULES
1463
1464 ###
1465 # Cleaning is done on three levels.
1466 # make clean     Delete most generated files
1467 #                Leave enough to build external modules
1468 # make mrproper  Delete the current configuration, and all generated files
1469 # make distclean Remove editor backup files, patch leftover files and the like
1470
1471 # Directories & files removed with 'make clean'
1472 CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1473                modules.builtin modules.builtin.modinfo modules.nsdeps \
1474                compile_commands.json .thinlto-cache rust/test \
1475                rust-project.json .vmlinux.objs .vmlinux.export.c
1476
1477 # Directories & files removed with 'make mrproper'
1478 MRPROPER_FILES += include/config include/generated          \
1479                   arch/$(SRCARCH)/include/generated .objdiff \
1480                   debian snap tar-install \
1481                   .config .config.old .version \
1482                   Module.symvers \
1483                   certs/signing_key.pem \
1484                   certs/x509.genkey \
1485                   vmlinux-gdb.py \
1486                   rpmbuild \
1487                   rust/libmacros.so
1488
1489 # clean - Delete most, but leave enough to build external modules
1490 #
1491 clean: rm-files := $(CLEAN_FILES)
1492
1493 PHONY += archclean vmlinuxclean
1494
1495 vmlinuxclean:
1496         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1497         $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1498
1499 clean: archclean vmlinuxclean resolve_btfids_clean
1500
1501 # mrproper - Delete all generated files, including .config
1502 #
1503 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1504 mrproper-dirs      := $(addprefix _mrproper_,scripts)
1505
1506 PHONY += $(mrproper-dirs) mrproper
1507 $(mrproper-dirs):
1508         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1509
1510 mrproper: clean $(mrproper-dirs)
1511         $(call cmd,rmfiles)
1512         @find . $(RCS_FIND_IGNORE) \
1513                 \( -name '*.rmeta' \) \
1514                 -type f -print | xargs rm -f
1515
1516 # distclean
1517 #
1518 PHONY += distclean
1519
1520 distclean: mrproper
1521         @find . $(RCS_FIND_IGNORE) \
1522                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1523                 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1524                 -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1525                 -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1526                 -type f -print | xargs rm -f
1527
1528
1529 # Packaging of the kernel to various formats
1530 # ---------------------------------------------------------------------------
1531
1532 %src-pkg: FORCE
1533         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1534 %pkg: include/config/kernel.release FORCE
1535         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1536
1537 # Brief documentation of the typical targets used
1538 # ---------------------------------------------------------------------------
1539
1540 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1541 boards := $(sort $(notdir $(boards)))
1542 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1543 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1544
1545 PHONY += help
1546 help:
1547         @echo  'Cleaning targets:'
1548         @echo  '  clean           - Remove most generated files but keep the config and'
1549         @echo  '                    enough build support to build external modules'
1550         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1551         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1552         @echo  ''
1553         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1554         @echo  ''
1555         @echo  'Other generic targets:'
1556         @echo  '  all             - Build all targets marked with [*]'
1557         @echo  '* vmlinux         - Build the bare kernel'
1558         @echo  '* modules         - Build all modules'
1559         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1560         @echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1561         @echo  '  dir/            - Build all files in dir and below'
1562         @echo  '  dir/file.[ois]  - Build specified target only'
1563         @echo  '  dir/file.ll     - Build the LLVM assembly file'
1564         @echo  '                    (requires compiler support for LLVM assembly generation)'
1565         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1566         @echo  '                    (requires a recent binutils and recent build (System.map))'
1567         @echo  '  dir/file.ko     - Build module including final link'
1568         @echo  '  modules_prepare - Set up for building external modules'
1569         @echo  '  tags/TAGS       - Generate tags file for editors'
1570         @echo  '  cscope          - Generate cscope index'
1571         @echo  '  gtags           - Generate GNU GLOBAL index'
1572         @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1573         @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1574         @echo  '  image_name      - Output the image name (use with make -s)'
1575         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1576          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1577          echo  ''
1578         @echo  'Static analysers:'
1579         @echo  '  checkstack      - Generate a list of stack hogs'
1580         @echo  '  versioncheck    - Sanity check on version.h usage'
1581         @echo  '  includecheck    - Check for duplicate included header files'
1582         @echo  '  export_report   - List the usages of all exported symbols'
1583         @echo  '  headerdep       - Detect inclusion cycles in headers'
1584         @echo  '  coccicheck      - Check with Coccinelle'
1585         @echo  '  clang-analyzer  - Check with clang static analyzer'
1586         @echo  '  clang-tidy      - Check with clang-tidy'
1587         @echo  ''
1588         @echo  'Tools:'
1589         @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1590         @echo  ''
1591         @echo  'Kernel selftest:'
1592         @echo  '  kselftest         - Build and run kernel selftest'
1593         @echo  '                      Build, install, and boot kernel before'
1594         @echo  '                      running kselftest on it'
1595         @echo  '                      Run as root for full coverage'
1596         @echo  '  kselftest-all     - Build kernel selftest'
1597         @echo  '  kselftest-install - Build and install kernel selftest'
1598         @echo  '  kselftest-clean   - Remove all generated kselftest files'
1599         @echo  '  kselftest-merge   - Merge all the config dependencies of'
1600         @echo  '                      kselftest to existing .config.'
1601         @echo  ''
1602         @echo  'Rust targets:'
1603         @echo  '  rustavailable   - Checks whether the Rust toolchain is'
1604         @echo  '                    available and, if not, explains why.'
1605         @echo  '  rustfmt         - Reformat all the Rust code in the kernel'
1606         @echo  '  rustfmtcheck    - Checks if all the Rust code in the kernel'
1607         @echo  '                    is formatted, printing a diff otherwise.'
1608         @echo  '  rustdoc         - Generate Rust documentation'
1609         @echo  '                    (requires kernel .config)'
1610         @echo  '  rusttest        - Runs the Rust tests'
1611         @echo  '                    (requires kernel .config; downloads external repos)'
1612         @echo  '  rust-analyzer   - Generate rust-project.json rust-analyzer support file'
1613         @echo  '                    (requires kernel .config)'
1614         @echo  '  dir/file.[os]   - Build specified target only'
1615         @echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1616         @echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1617         @echo  '                    The output is not intended to be compilable.'
1618         @echo  '  dir/file.ll     - Build the LLVM assembly file'
1619         @echo  ''
1620         @$(if $(dtstree), \
1621                 echo 'Devicetree:'; \
1622                 echo '* dtbs             - Build device tree blobs for enabled boards'; \
1623                 echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1624                 echo '  dt_binding_check - Validate device tree binding documents'; \
1625                 echo '  dtbs_check       - Validate device tree source files';\
1626                 echo '')
1627
1628         @echo 'Userspace tools targets:'
1629         @echo '  use "make tools/help"'
1630         @echo '  or  "cd tools; make help"'
1631         @echo  ''
1632         @echo  'Kernel packaging:'
1633         @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1634         @echo  ''
1635         @echo  'Documentation targets:'
1636         @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1637         @echo  ''
1638         @echo  'Architecture-specific targets ($(SRCARCH)):'
1639         @$(or $(archhelp),\
1640                 echo '  No architecture-specific help defined for $(SRCARCH)')
1641         @echo  ''
1642         @$(if $(boards), \
1643                 $(foreach b, $(boards), \
1644                 printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1645                 echo '')
1646         @$(if $(board-dirs), \
1647                 $(foreach b, $(board-dirs), \
1648                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1649                 printf "  %-16s - Show all of the above\\n" help-boards; \
1650                 echo '')
1651
1652         @echo  '  make V=n   [targets] 1: verbose build'
1653         @echo  '                       2: give reason for rebuild of target'
1654         @echo  '                       V=1 and V=2 can be combined with V=12'
1655         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1656         @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1657         @echo  '                       (sparse by default)'
1658         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1659         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1660         @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1661         @echo  '                1: warnings which may be relevant and do not occur too often'
1662         @echo  '                2: warnings which occur quite often but may still be relevant'
1663         @echo  '                3: more obscure warnings, can most likely be ignored'
1664         @echo  '                e: warnings are being treated as errors'
1665         @echo  '                Multiple levels can be combined with W=12 or W=123'
1666         @$(if $(dtstree), \
1667                 echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1668                 echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1669                 )
1670         @echo  ''
1671         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1672         @echo  'For further info see the ./README file'
1673
1674
1675 help-board-dirs := $(addprefix help-,$(board-dirs))
1676
1677 help-boards: $(help-board-dirs)
1678
1679 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1680
1681 $(help-board-dirs): help-%:
1682         @echo  'Architecture-specific targets ($(SRCARCH) $*):'
1683         @$(if $(boards-per-dir), \
1684                 $(foreach b, $(boards-per-dir), \
1685                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1686                 echo '')
1687
1688
1689 # Documentation targets
1690 # ---------------------------------------------------------------------------
1691 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1692                linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1693 PHONY += $(DOC_TARGETS)
1694 $(DOC_TARGETS):
1695         $(Q)$(MAKE) $(build)=Documentation $@
1696
1697
1698 # Rust targets
1699 # ---------------------------------------------------------------------------
1700
1701 # "Is Rust available?" target
1702 PHONY += rustavailable
1703 rustavailable:
1704         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1705
1706 # Documentation target
1707 #
1708 # Using the singular to avoid running afoul of `no-dot-config-targets`.
1709 PHONY += rustdoc
1710 rustdoc: prepare
1711         $(Q)$(MAKE) $(build)=rust $@
1712
1713 # Testing target
1714 PHONY += rusttest
1715 rusttest: prepare
1716         $(Q)$(MAKE) $(build)=rust $@
1717
1718 # Formatting targets
1719 PHONY += rustfmt rustfmtcheck
1720
1721 # We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1722 #
1723 # We match using absolute paths since `find` does not resolve them
1724 # when matching, which is a problem when e.g. `srctree` is `..`.
1725 # We `grep` afterwards in order to remove the directory entry itself.
1726 rustfmt:
1727         $(Q)find $(abs_srctree) -type f -name '*.rs' \
1728                 -o -path $(abs_srctree)/rust/alloc -prune \
1729                 -o -path $(abs_objtree)/rust/test -prune \
1730                 | grep -Fv $(abs_srctree)/rust/alloc \
1731                 | grep -Fv $(abs_objtree)/rust/test \
1732                 | grep -Fv generated \
1733                 | xargs $(RUSTFMT) $(rustfmt_flags)
1734
1735 rustfmtcheck: rustfmt_flags = --check
1736 rustfmtcheck: rustfmt
1737
1738 # Misc
1739 # ---------------------------------------------------------------------------
1740
1741 PHONY += misc-check
1742 misc-check:
1743         $(Q)$(srctree)/scripts/misc-check
1744
1745 all: misc-check
1746
1747 PHONY += scripts_gdb
1748 scripts_gdb: prepare0
1749         $(Q)$(MAKE) $(build)=scripts/gdb
1750         $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1751
1752 ifdef CONFIG_GDB_SCRIPTS
1753 all: scripts_gdb
1754 endif
1755
1756 else # KBUILD_EXTMOD
1757
1758 filechk_kernel.release = echo $(KERNELRELEASE)
1759
1760 ###
1761 # External module support.
1762 # When building external modules the kernel used as basis is considered
1763 # read-only, and no consistency checks are made and the make
1764 # system is not used on the basis kernel. If updates are required
1765 # in the basis kernel ordinary make commands (without M=...) must be used.
1766
1767 # We are always building only modules.
1768 KBUILD_BUILTIN :=
1769 KBUILD_MODULES := 1
1770
1771 build-dir := $(KBUILD_EXTMOD)
1772
1773 compile_commands.json: $(extmod_prefix)compile_commands.json
1774 PHONY += compile_commands.json
1775
1776 clean-dirs := $(KBUILD_EXTMOD)
1777 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1778         $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1779
1780 PHONY += prepare
1781 # now expand this into a simple variable to reduce the cost of shell evaluations
1782 prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1783 prepare:
1784         @if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1785                 echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1786                 echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1787                 echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1788         fi
1789
1790 PHONY += help
1791 help:
1792         @echo  '  Building external modules.'
1793         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1794         @echo  ''
1795         @echo  '  modules         - default target, build the module(s)'
1796         @echo  '  modules_install - install the module'
1797         @echo  '  clean           - remove generated files in module directory only'
1798         @echo  '  rust-analyzer   - generate rust-project.json rust-analyzer support file'
1799         @echo  ''
1800
1801 ifndef CONFIG_MODULES
1802 modules modules_install: __external_modules_error
1803 __external_modules_error:
1804         @echo >&2 '***'
1805         @echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1806         @echo >&2 '*** You cannot build or install external modules.'
1807         @echo >&2 '***'
1808         @false
1809 endif
1810
1811 endif # KBUILD_EXTMOD
1812
1813 # ---------------------------------------------------------------------------
1814 # Modules
1815
1816 PHONY += modules modules_install modules_sign modules_prepare
1817
1818 modules_install:
1819         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1820         sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1821
1822 ifeq ($(CONFIG_MODULE_SIG),y)
1823 # modules_sign is a subset of modules_install.
1824 # 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1825 modules_sign: modules_install
1826         @:
1827 else
1828 modules_sign:
1829         @echo >&2 '***'
1830         @echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1831         @echo >&2 '***'
1832         @false
1833 endif
1834
1835 ifdef CONFIG_MODULES
1836
1837 $(MODORDER): $(build-dir)
1838         @:
1839
1840 # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1841 # This is solely useful to speed up test compiles.
1842 modules: modpost
1843 ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1844         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1845 endif
1846
1847 PHONY += modules_check
1848 modules_check: $(MODORDER)
1849         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1850
1851 else # CONFIG_MODULES
1852
1853 modules:
1854         @:
1855
1856 KBUILD_MODULES :=
1857
1858 endif # CONFIG_MODULES
1859
1860 PHONY += modpost
1861 modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1862          $(if $(KBUILD_MODULES), modules_check)
1863         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1864
1865 # Single targets
1866 # ---------------------------------------------------------------------------
1867 # To build individual files in subdirectories, you can do like this:
1868 #
1869 #   make foo/bar/baz.s
1870 #
1871 # The supported suffixes for single-target are listed in 'single-targets'
1872 #
1873 # To build only under specific subdirectories, you can do like this:
1874 #
1875 #   make foo/bar/baz/
1876
1877 ifdef single-build
1878
1879 # .ko is special because modpost is needed
1880 single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1881 single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1882                 $(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1883
1884 $(single-ko): single_modules
1885         @:
1886 $(single-no-ko): $(build-dir)
1887         @:
1888
1889 # Remove MODORDER when done because it is not the real one.
1890 PHONY += single_modules
1891 single_modules: $(single-no-ko) modules_prepare
1892         $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1893         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1894 ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1895         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1896 endif
1897         $(Q)rm -f $(MODORDER)
1898
1899 single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1900
1901 KBUILD_MODULES := 1
1902
1903 endif
1904
1905 # Preset locale variables to speed up the build process. Limit locale
1906 # tweaks to this spot to avoid wrong language settings when running
1907 # make menuconfig etc.
1908 # Error messages still appears in the original language
1909 PHONY += $(build-dir)
1910 $(build-dir): prepare
1911         $(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1912
1913 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1914 PHONY += $(clean-dirs) clean
1915 $(clean-dirs):
1916         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1917
1918 clean: $(clean-dirs)
1919         $(call cmd,rmfiles)
1920         @find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1921                 \( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1922                 -o -name '*.ko.*' \
1923                 -o -name '*.dtb' -o -name '*.dtbo' \
1924                 -o -name '*.dtb.S' -o -name '*.dtbo.S' \
1925                 -o -name '*.dt.yaml' \
1926                 -o -name '*.dwo' -o -name '*.lst' \
1927                 -o -name '*.su' -o -name '*.mod' \
1928                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1929                 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1930                 -o -name '*.asn1.[ch]' \
1931                 -o -name '*.symtypes' -o -name 'modules.order' \
1932                 -o -name '*.c.[012]*.*' \
1933                 -o -name '*.ll' \
1934                 -o -name '*.gcno' \
1935                 -o -name '*.*.symversions' \) -type f -print \
1936                 -o -name '.tmp_*' -print \
1937                 | xargs rm -rf
1938
1939 # Generate tags for editors
1940 # ---------------------------------------------------------------------------
1941 quiet_cmd_tags = GEN     $@
1942       cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1943
1944 tags TAGS cscope gtags: FORCE
1945         $(call cmd,tags)
1946
1947 # IDE support targets
1948 PHONY += rust-analyzer
1949 rust-analyzer:
1950         $(Q)$(MAKE) $(build)=rust $@
1951
1952 # Script to generate missing namespace dependencies
1953 # ---------------------------------------------------------------------------
1954
1955 PHONY += nsdeps
1956 nsdeps: export KBUILD_NSDEPS=1
1957 nsdeps: modules
1958         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1959
1960 # Clang Tooling
1961 # ---------------------------------------------------------------------------
1962
1963 quiet_cmd_gen_compile_commands = GEN     $@
1964       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1965
1966 $(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1967         $(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
1968         $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1969         $(call if_changed,gen_compile_commands)
1970
1971 targets += $(extmod_prefix)compile_commands.json
1972
1973 PHONY += clang-tidy clang-analyzer
1974
1975 ifdef CONFIG_CC_IS_CLANG
1976 quiet_cmd_clang_tools = CHECK   $<
1977       cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1978
1979 clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1980         $(call cmd,clang_tools)
1981 else
1982 clang-tidy clang-analyzer:
1983         @echo "$@ requires CC=clang" >&2
1984         @false
1985 endif
1986
1987 # Scripts to check various things for consistency
1988 # ---------------------------------------------------------------------------
1989
1990 PHONY += includecheck versioncheck coccicheck export_report
1991
1992 includecheck:
1993         find $(srctree)/* $(RCS_FIND_IGNORE) \
1994                 -name '*.[hcS]' -type f -print | sort \
1995                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1996
1997 versioncheck:
1998         find $(srctree)/* $(RCS_FIND_IGNORE) \
1999                 -name '*.[hcS]' -type f -print | sort \
2000                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2001
2002 coccicheck:
2003         $(Q)$(BASH) $(srctree)/scripts/$@
2004
2005 export_report:
2006         $(PERL) $(srctree)/scripts/export_report.pl
2007
2008 PHONY += checkstack kernelrelease kernelversion image_name
2009
2010 # UML needs a little special treatment here.  It wants to use the host
2011 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2012 # else wants $(ARCH), including people doing cross-builds, which means
2013 # that $(SUBARCH) doesn't work here.
2014 ifeq ($(ARCH), um)
2015 CHECKSTACK_ARCH := $(SUBARCH)
2016 else
2017 CHECKSTACK_ARCH := $(ARCH)
2018 endif
2019 checkstack:
2020         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2021         $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2022
2023 kernelrelease:
2024         @$(filechk_kernel.release)
2025
2026 kernelversion:
2027         @echo $(KERNELVERSION)
2028
2029 image_name:
2030         @echo $(KBUILD_IMAGE)
2031
2032 PHONY += run-command
2033 run-command:
2034         $(Q)$(KBUILD_RUN_COMMAND)
2035
2036 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2037       cmd_rmfiles = rm -rf $(rm-files)
2038
2039 # read saved command lines for existing targets
2040 existing-targets := $(wildcard $(sort $(targets)))
2041
2042 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2043
2044 endif # config-build
2045 endif # mixed-build
2046 endif # need-sub-make
2047
2048 PHONY += FORCE
2049 FORCE:
2050
2051 # Declare the contents of the PHONY variable as phony.  We keep that
2052 # information in a variable so we can use it in if_changed and friends.
2053 .PHONY: $(PHONY)