xref: /linux/Makefile (revision 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 7
3PATCHLEVEL = 4
4SUBLEVEL = 0
5EXTRAVERSION = -rc1
6NAME = Baby Opossum Posse
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
14ifeq ($(filter output-sync,$(.FEATURES)),)
15$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(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
22PHONY := __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
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_output := $(CURDIR)
44
45ifneq ($(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)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport 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) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83  KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
97quiet=silent_
98override KBUILD_VERBOSE :=
99endif
100
101export quiet Q KBUILD_VERBOSE
102
103# Call a source code checker (by default, "sparse") as part of the
104# C compilation.
105#
106# Use 'make C=1' to enable checking of only re-compiled files.
107# Use 'make C=2' to enable checking of *all* source files, regardless
108# of whether they are re-compiled or not.
109#
110# See the file "Documentation/dev-tools/sparse.rst" for more details,
111# including where to get the "sparse" utility.
112
113ifeq ("$(origin C)", "command line")
114  KBUILD_CHECKSRC = $(C)
115endif
116ifndef KBUILD_CHECKSRC
117  KBUILD_CHECKSRC = 0
118endif
119
120export KBUILD_CHECKSRC
121
122# Enable "clippy" (a linter) as part of the Rust compilation.
123#
124# Use 'make CLIPPY=1' to enable it.
125ifeq ("$(origin CLIPPY)", "command line")
126  KBUILD_CLIPPY := $(CLIPPY)
127endif
128
129export KBUILD_CLIPPY
130
131# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
132# directory of external module to build. Setting M= takes precedence.
133ifeq ("$(origin M)", "command line")
134  KBUILD_EXTMOD := $(M)
135endif
136
137ifeq ("$(origin MO)", "command line")
138  KBUILD_EXTMOD_OUTPUT := $(MO)
139endif
140
141$(if $(word 2, $(KBUILD_EXTMOD)), \
142	$(error building multiple external modules is not supported))
143
144$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
145	$(error module directory path cannot contain '$x')))
146
147# Remove trailing slashes
148ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
149KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
150endif
151
152export KBUILD_EXTMOD
153
154ifeq ("$(origin W)", "command line")
155  KBUILD_EXTRA_WARN := $(W)
156endif
157
158export KBUILD_EXTRA_WARN
159
160# Kbuild will save output files in the current working directory.
161# This does not need to match to the root of the kernel source tree.
162#
163# For example, you can do this:
164#
165#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
166#
167# If you want to save output files in a different location, there are
168# two syntaxes to specify it.
169#
170# 1) O=
171# Use "make O=dir/to/store/output/files/"
172#
173# 2) Set KBUILD_OUTPUT
174# Set the environment variable KBUILD_OUTPUT to point to the output directory.
175# export KBUILD_OUTPUT=dir/to/store/output/files/; make
176#
177# The O= assignment takes precedence over the KBUILD_OUTPUT environment
178# variable.
179
180ifeq ("$(origin O)", "command line")
181  KBUILD_OUTPUT := $(O)
182endif
183
184ifdef KBUILD_EXTMOD
185    ifdef KBUILD_OUTPUT
186        objtree := $(realpath $(KBUILD_OUTPUT))
187        $(if $(objtree),,$(error specified kernel directory "$(KBUILD_OUTPUT)" does not exist))
188    else
189        objtree := $(abs_srctree)
190    endif
191    # If Make is invoked from the kernel directory (either kernel
192    # source directory or kernel build directory), external modules
193    # are built in $(KBUILD_EXTMOD) for backward compatibility,
194    # otherwise, built in the current directory.
195    output := $(or $(KBUILD_EXTMOD_OUTPUT),$(if $(filter $(CURDIR),$(objtree) $(abs_srctree)),$(KBUILD_EXTMOD)))
196    # KBUILD_EXTMOD might be a relative path. Remember its absolute path before
197    # Make changes the working directory.
198    srcroot := $(realpath $(KBUILD_EXTMOD))
199    $(if $(srcroot),,$(error specified external module directory "$(KBUILD_EXTMOD)" does not exist))
200else
201    objtree := .
202    output := $(KBUILD_OUTPUT)
203endif
204
205export objtree srcroot
206
207# Do we want to change the working directory?
208ifneq ($(output),)
209# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
210$(shell mkdir -p "$(output)")
211# $(realpath ...) resolves symlinks
212abs_output := $(realpath $(output))
213$(if $(abs_output),,$(error failed to create output directory "$(output)"))
214endif
215
216ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
217$(error source directory cannot contain spaces or colons)
218endif
219
220export sub_make_done := 1
221
222endif # sub_make_done
223
224ifeq ($(abs_output),$(CURDIR))
225# Suppress "Entering directory ..." if we are at the final work directory.
226no-print-directory := --no-print-directory
227else
228# Recursion to show "Entering directory ..."
229need-sub-make := 1
230endif
231
232ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
233# If --no-print-directory is unset, recurse once again to set it.
234# You may end up recursing into __sub-make twice. This is needed due to the
235# behavior change in GNU Make 4.4.1.
236need-sub-make := 1
237endif
238
239ifeq ($(need-sub-make),1)
240
241PHONY += $(MAKECMDGOALS) __sub-make
242
243$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
244	@:
245
246# Invoke a second make in the output directory, passing relevant variables
247__sub-make:
248	$(Q)$(MAKE) $(no-print-directory) -C $(abs_output) \
249	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
250
251else # need-sub-make
252
253# We process the rest of the Makefile if this is the final invocation of make
254
255ifndef KBUILD_EXTMOD
256srcroot := $(abs_srctree)
257endif
258
259ifeq ($(srcroot),$(CURDIR))
260building_out_of_srctree :=
261else
262export building_out_of_srctree := 1
263endif
264
265ifdef KBUILD_ABS_SRCTREE
266    # Do nothing. Use the absolute path.
267else ifeq ($(srcroot),$(CURDIR))
268    # Building in the source.
269    srcroot := .
270else ifeq ($(srcroot)/,$(dir $(CURDIR)))
271    # Building in a subdirectory of the source.
272    srcroot := ..
273endif
274
275export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot))
276
277ifdef building_out_of_srctree
278export VPATH := $(srcroot)
279else
280VPATH :=
281endif
282
283# To make sure we do not include .config for any of the *config targets
284# catch them early, and hand them over to scripts/kconfig/Makefile
285# It is allowed to specify more targets when calling make, including
286# mixing *config targets and build targets.
287# For example 'make oldconfig all'.
288# Detect when mixed targets is specified, and make a second invocation
289# of make so .config is not included in this case either (for *config).
290
291version_h := include/generated/uapi/linux/version.h
292
293clean-targets := %clean mrproper cleandocs
294no-dot-config-targets := $(clean-targets) \
295			 cscope gtags TAGS tags help% %docs check% coccicheck \
296			 kconfig-sym-check \
297			 $(version_h) headers headers_% archheaders archscripts \
298			 %asm-generic kernelversion %src-pkg dt_binding_check \
299			 dt_style_selftest \
300			 outputmakefile rustavailable rustfmt rustfmtcheck \
301			 scripts_gen_init_cpio \
302			 run-command
303no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
304			  image_name
305single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.header-check %/
306
307config-build	:=
308mixed-build	:=
309need-config	:= 1
310may-sync-config	:= 1
311single-build	:=
312
313ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
314    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
315        need-config :=
316    endif
317endif
318
319ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
320    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
321        may-sync-config :=
322    endif
323endif
324
325need-compiler := $(may-sync-config)
326
327ifneq ($(KBUILD_EXTMOD),)
328    may-sync-config :=
329endif
330
331ifeq ($(KBUILD_EXTMOD),)
332    ifneq ($(filter %config,$(MAKECMDGOALS)),)
333        config-build := 1
334        ifneq ($(words $(MAKECMDGOALS)),1)
335            mixed-build := 1
336        endif
337    endif
338endif
339
340# We cannot build single targets and the others at the same time
341ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
342    single-build := 1
343    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
344        mixed-build := 1
345    endif
346endif
347
348# For "make -j clean all", "make -j mrproper defconfig all", etc.
349ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
350    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
351        mixed-build := 1
352    endif
353endif
354
355# install and modules_install need also be processed one by one
356ifneq ($(filter install,$(MAKECMDGOALS)),)
357    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
358        mixed-build := 1
359    endif
360endif
361
362ifdef mixed-build
363# ===========================================================================
364# We're called with mixed targets (*config and build targets).
365# Handle them one by one.
366
367PHONY += $(MAKECMDGOALS) __build_one_by_one
368
369$(MAKECMDGOALS): __build_one_by_one
370	@:
371
372__build_one_by_one:
373	$(Q)set -e; \
374	for i in $(MAKECMDGOALS); do \
375		$(MAKE) -f $(srctree)/Makefile $$i; \
376	done
377
378else # !mixed-build
379
380include $(srctree)/scripts/Kbuild.include
381
382# Read KERNELRELEASE from include/config/kernel.release (if it exists)
383KERNELRELEASE = $(call read-file, $(objtree)/include/config/kernel.release)
384KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
385export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
386
387include $(srctree)/scripts/subarch.include
388
389# Cross compiling and selecting different set of gcc/bin-utils
390# ---------------------------------------------------------------------------
391#
392# When performing cross compilation for other architectures ARCH shall be set
393# to the target architecture. (See arch/* for the possibilities).
394# ARCH can be set during invocation of make:
395# make ARCH=arm64
396# Another way is to have ARCH set in the environment.
397# The default ARCH is the host where make is executed.
398
399# CROSS_COMPILE specify the prefix used for all executables used
400# during compilation. Only gcc and related bin-utils executables
401# are prefixed with $(CROSS_COMPILE).
402# CROSS_COMPILE can be set on the command line
403# make CROSS_COMPILE=aarch64-linux-gnu-
404# Alternatively CROSS_COMPILE can be set in the environment.
405# Default value for CROSS_COMPILE is not to prefix executables
406# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
407ARCH		?= $(SUBARCH)
408
409# Architecture as present in compile.h
410UTS_MACHINE 	:= $(ARCH)
411SRCARCH 	:= $(ARCH)
412
413# Additional ARCH settings for x86
414ifeq ($(ARCH),i386)
415        SRCARCH := x86
416endif
417ifeq ($(ARCH),x86_64)
418        SRCARCH := x86
419endif
420
421# Additional ARCH settings for sparc
422ifeq ($(ARCH),sparc32)
423       SRCARCH := sparc
424endif
425ifeq ($(ARCH),sparc64)
426       SRCARCH := sparc
427endif
428
429# Additional ARCH settings for parisc
430ifeq ($(ARCH),parisc64)
431       SRCARCH := parisc
432endif
433
434export cross_compiling :=
435ifneq ($(SRCARCH),$(SUBARCH))
436cross_compiling := 1
437endif
438
439KCONFIG_CONFIG	?= .config
440export KCONFIG_CONFIG
441
442# SHELL used by kbuild
443CONFIG_SHELL := sh
444
445HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
446HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
447HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
448
449ifneq ($(LLVM),)
450ifneq ($(filter %/,$(LLVM)),)
451LLVM_PREFIX := $(LLVM)
452else ifneq ($(filter -%,$(LLVM)),)
453LLVM_SUFFIX := $(LLVM)
454else ifneq ($(LLVM),1)
455$(error Invalid value for LLVM, see Documentation/kbuild/llvm.rst)
456endif
457
458HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
459HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
460else
461HOSTCC	= gcc
462HOSTCXX	= g++
463endif
464HOSTRUSTC = rustc
465HOSTPKG_CONFIG	= pkg-config
466
467# the KERNELDOC macro needs to be exported, as scripts/Makefile.build
468# has a logic to call it
469KERNELDOC       = $(srctree)/tools/docs/kernel-doc
470export KERNELDOC
471
472KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
473			 -O2 -fomit-frame-pointer -std=gnu11
474KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
475KBUILD_USERLDFLAGS := $(USERLDFLAGS)
476
477# These flags apply to all Rust code in the tree, including the kernel and
478# host programs.
479#
480# `-Aclippy::comparison_chain`: the lint has been demoted since 1.87.
481# `-Aclippy::unwrap_or_default`: the lint is buggy [1] and ignores our
482# MSRV. It can trigger depending on the optimization level.
483# [1] https://github.com/rust-lang/rust-clippy/issues/17379
484export rust_common_flags := --edition=2021 \
485			    -Zbinary_dep_depinfo=y \
486			    -Astable_features \
487			    -Aunused_features \
488			    -Dnon_ascii_idents \
489			    -Dunsafe_op_in_unsafe_fn \
490			    -Wmissing_docs \
491			    -Wrust_2018_idioms \
492			    -Wunreachable_pub \
493			    -Wclippy::all \
494			    -Wclippy::as_ptr_cast_mut \
495			    -Wclippy::as_underscore \
496			    -Wclippy::cast_lossless \
497			    -Aclippy::collapsible_if \
498			    -Aclippy::collapsible_match \
499			    -Aclippy::comparison_chain \
500			    -Wclippy::ignored_unit_patterns \
501			    -Aclippy::incompatible_msrv \
502			    -Wclippy::mut_mut \
503			    -Wclippy::needless_bitwise_bool \
504			    -Aclippy::needless_lifetimes \
505			    -Wclippy::no_mangle_with_rust_abi \
506			    -Wclippy::ptr_as_ptr \
507			    -Wclippy::ptr_cast_constness \
508			    -Wclippy::ref_as_ptr \
509			    -Wclippy::undocumented_unsafe_blocks \
510			    -Aclippy::uninlined_format_args \
511			    -Wclippy::unnecessary_safety_comment \
512			    -Wclippy::unnecessary_safety_doc \
513			    -Aclippy::unwrap_or_default \
514			    -Wrustdoc::missing_crate_level_docs \
515			    -Wrustdoc::unescaped_backticks
516
517KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
518		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
519KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
520		       -I $(srctree)/scripts/include
521KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
522			-Zallow-features=
523KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
524KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
525KBUILD_PROCMACROLDFLAGS := $(or $(PROCMACROLDFLAGS),$(KBUILD_HOSTLDFLAGS))
526
527# Make variables (CC, etc...)
528CPP		= $(CC) -E
529ifneq ($(LLVM),)
530CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
531LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
532AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
533LLVM_LINK	= $(LLVM_PREFIX)llvm-link$(LLVM_SUFFIX)
534NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
535OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
536OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
537READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
538STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
539ifeq ($(filter -fuse-ld=% --ld-path=%,$(KBUILD_HOSTLDFLAGS)),)
540KBUILD_HOSTLDFLAGS += -fuse-ld=lld
541endif
542else
543CC		= $(CROSS_COMPILE)gcc
544LD		= $(CROSS_COMPILE)ld
545AR		= $(CROSS_COMPILE)ar
546NM		= $(CROSS_COMPILE)nm
547OBJCOPY		= $(CROSS_COMPILE)objcopy
548OBJDUMP		= $(CROSS_COMPILE)objdump
549READELF		= $(CROSS_COMPILE)readelf
550STRIP		= $(CROSS_COMPILE)strip
551endif
552RUSTC		= rustc
553RUSTDOC		= rustdoc
554RUSTFMT		= rustfmt
555CLIPPY_DRIVER	= clippy-driver
556BINDGEN		= bindgen
557PAHOLE		= pahole
558RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
559LEX		= flex
560YACC		= bison
561AWK		= awk
562INSTALLKERNEL  := installkernel
563PERL		= perl
564PYTHON3		= python3
565CHECK		= sparse
566BASH		= bash
567KGZIP		= gzip
568KBZIP2		= bzip2
569KLZOP		= lzop
570LZMA		= lzma
571LZ4		= lz4
572XZ		= xz
573ZSTD		= zstd
574# The kernel image is compressed with pigz, on the job slots make has free,
575# if it is installed. Everything else uses KGZIP.
576KPGZIP		:= $(if $(shell command -v pigz 2>/dev/null),$(PYTHON3) $(abs_srctree)/scripts/jobserver-exec pigz -p %PARALLELISM%,$(KGZIP))
577TAR		= tar
578
579CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
580		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
581NOSTDINC_FLAGS :=
582CFLAGS_MODULE   =
583RUSTFLAGS_MODULE =
584AFLAGS_MODULE   =
585LDFLAGS_MODULE  =
586CFLAGS_KERNEL	=
587RUSTFLAGS_KERNEL =
588AFLAGS_KERNEL	=
589LDFLAGS_vmlinux =
590
591# Use USERINCLUDE when you must reference the UAPI directories only.
592USERINCLUDE    := \
593		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
594		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
595		-I$(srctree)/include/uapi \
596		-I$(objtree)/include/generated/uapi \
597                -include $(srctree)/include/linux/compiler-version.h \
598                -include $(srctree)/include/linux/kconfig.h
599
600# Use LINUXINCLUDE when you must reference the include/ directory.
601# Needed to be compatible with the O= option
602LINUXINCLUDE    := \
603		-I$(srctree)/arch/$(SRCARCH)/include \
604		-I$(objtree)/arch/$(SRCARCH)/include/generated \
605		-I$(srctree)/include \
606		-I$(objtree)/include \
607		$(USERINCLUDE)
608
609KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
610
611KBUILD_CFLAGS :=
612KBUILD_CFLAGS += -fshort-wchar
613KBUILD_CFLAGS += -funsigned-char
614KBUILD_CFLAGS += -fno-common
615KBUILD_CFLAGS += -fno-PIE
616KBUILD_CFLAGS += -fno-strict-aliasing
617
618KBUILD_CPPFLAGS := -D__KERNEL__
619KBUILD_RUSTFLAGS := $(rust_common_flags) \
620		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
621		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
622		    -Csymbol-mangling-version=v0 \
623		    -Crelocation-model=static \
624		    -Zfunction-sections=n \
625		    -Wclippy::float_arithmetic
626KBUILD_RUSTFLAGS_OPTION_CHKS :=
627
628KBUILD_AFLAGS_KERNEL :=
629KBUILD_CFLAGS_KERNEL :=
630KBUILD_RUSTFLAGS_KERNEL :=
631KBUILD_AFLAGS_MODULE  := -DMODULE
632KBUILD_CFLAGS_MODULE  := -DMODULE
633KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
634KBUILD_LDFLAGS_MODULE :=
635KBUILD_LDFLAGS :=
636CLANG_FLAGS :=
637
638ifeq ($(KBUILD_CLIPPY),1)
639	RUSTC_OR_CLIPPY_QUIET := CLIPPY
640	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
641else
642	RUSTC_OR_CLIPPY_QUIET := RUSTC
643	RUSTC_OR_CLIPPY = $(RUSTC)
644endif
645
646# Allows the usage of unstable features in stable compilers.
647export RUSTC_BOOTSTRAP := 1
648
649# Allows finding `.clippy.toml` in out-of-srctree builds.
650export CLIPPY_CONF_DIR := $(srctree)
651
652export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
653export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN LLVM_LINK
654export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
655export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
656export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
657export KGZIP KPGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD TAR
658export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS KBUILD_PROCMACROLDFLAGS LDFLAGS_MODULE
659export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
660
661export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
662export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
663export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE KBUILD_RUSTFLAGS_OPTION_CHKS
664export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
665export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
666export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
667
668# Files to ignore in find ... statements
669
670export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
671			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
672			  -prune -o
673
674# ===========================================================================
675# Rules shared between *config targets and build targets
676
677# Basic helpers built in scripts/basic/
678PHONY += scripts_basic
679scripts_basic: KBUILD_HOSTCFLAGS := $(KBUILD_HOSTCFLAGS)
680scripts_basic: KBUILD_HOSTLDFLAGS := $(KBUILD_HOSTLDFLAGS)
681scripts_basic:
682	$(Q)$(MAKE) $(build)=scripts/basic
683
684PHONY += outputmakefile
685ifdef building_out_of_srctree
686# Before starting out-of-tree build, make sure the source tree is clean.
687# outputmakefile generates a Makefile in the output directory, if using a
688# separate output directory. This allows convenient use of make in the
689# output directory.
690# At the same time as the output Makefile is generated, generate .gitignore to
691# ignore the whole output directory
692
693ifdef KBUILD_EXTMOD
694print_env_for_makefile = \
695	echo "export KBUILD_OUTPUT = $(objtree)"; \
696	echo "export KBUILD_EXTMOD = $(realpath $(srcroot))" ; \
697	echo "export KBUILD_EXTMOD_OUTPUT = $(CURDIR)"
698else
699print_env_for_makefile = \
700	echo "export KBUILD_OUTPUT = $(CURDIR)"
701endif
702
703filechk_makefile = { \
704	echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \
705	$(print_env_for_makefile); \
706	echo "include $(abs_srctree)/Makefile"; \
707	}
708
709PHONY += $(CURDIR)/Makefile
710$(CURDIR)/Makefile: FORCE
711	$(call filechk,makefile)
712
713outputmakefile: $(CURDIR)/Makefile
714ifeq ($(KBUILD_EXTMOD),)
715	@if [ -f $(srctree)/.config -o \
716		 -d $(srctree)/include/config -o \
717		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
718		echo >&2 "***"; \
719		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
720		echo >&2 "*** in $(abs_srctree)";\
721		echo >&2 "***"; \
722		false; \
723	fi
724else
725	@if [ -f $(srcroot)/modules.order ]; then \
726		echo >&2 "***"; \
727		echo >&2 "*** The external module source tree is not clean."; \
728		echo >&2 "*** Please run 'make -C $(abs_srctree) M=$(realpath $(srcroot)) clean'"; \
729		echo >&2 "***"; \
730		false; \
731	fi
732endif
733	$(Q)ln -fsn $(srcroot) source
734	$(Q)test -e .gitignore || \
735	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
736endif
737
738# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
739# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
740# CC_VERSION_TEXT, RUSTC_VERSION_TEXT and PAHOLE_VERSION are referenced from
741# Kconfig (so they need export), and from include/config/auto.conf.cmd to
742# detect the version changes between builds.
743CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
744RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
745PAHOLE_VERSION = $(shell $(srctree)/scripts/pahole-version.sh $(PAHOLE))
746
747ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
748include $(srctree)/scripts/Makefile.clang
749endif
750
751# Include this also for config targets because some architectures need
752# cc-cross-prefix to determine CROSS_COMPILE.
753ifdef need-compiler
754include $(srctree)/scripts/Makefile.compiler
755endif
756
757ifdef config-build
758# ===========================================================================
759# *config targets only - make sure prerequisites are updated, and descend
760# in scripts/kconfig to make the *config target
761
762# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
763# KBUILD_DEFCONFIG may point out an alternative default configuration
764# used for 'make defconfig'
765include $(srctree)/arch/$(SRCARCH)/Makefile
766export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT PAHOLE_VERSION
767
768config: outputmakefile scripts_basic FORCE
769	$(Q)$(MAKE) $(build)=scripts/kconfig $@
770
771%config: outputmakefile scripts_basic FORCE
772	$(Q)$(MAKE) $(build)=scripts/kconfig $@
773
774else #!config-build
775# ===========================================================================
776# Build targets only - this includes vmlinux, arch-specific targets, clean
777# targets and others. In general all targets except *config targets.
778
779# If building an external module we do not care about the all: rule
780# but instead __all depend on modules
781PHONY += all
782ifeq ($(KBUILD_EXTMOD),)
783__all: all
784else
785__all: modules
786endif
787
788targets :=
789
790# Decide whether to build built-in, modular, or both.
791# Normally, just do built-in.
792
793KBUILD_MODULES :=
794KBUILD_BUILTIN := y
795
796# If we have only "make modules", don't compile built-in objects.
797ifeq ($(MAKECMDGOALS),modules)
798  KBUILD_BUILTIN :=
799endif
800
801# If we have "make <whatever> modules", compile modules
802# in addition to whatever we do anyway.
803# Just "make" or "make all" shall build modules as well
804
805ifneq ($(filter all modules nsdeps compile_commands.json clang-% sbom,$(MAKECMDGOALS)),)
806  KBUILD_MODULES := y
807endif
808
809ifeq ($(MAKECMDGOALS),)
810  KBUILD_MODULES := y
811endif
812
813export KBUILD_MODULES KBUILD_BUILTIN
814
815ifdef need-config
816include $(objtree)/include/config/auto.conf
817endif
818
819CC_FLAGS_DIALECT := -std=gnu11
820# Allow including a tagged struct or union anonymously in another struct/union.
821CC_FLAGS_DIALECT += $(CONFIG_CC_MS_EXTENSIONS)
822# Clang enables warnings about GNU and Microsoft extensions by default, disable
823# them because this is expected with the above options.
824ifdef CONFIG_CC_IS_CLANG
825CC_FLAGS_DIALECT += -Wno-gnu
826CC_FLAGS_DIALECT += -Wno-microsoft-anon-tag
827endif
828export CC_FLAGS_DIALECT
829KBUILD_CFLAGS += $(CC_FLAGS_DIALECT)
830
831ifeq ($(KBUILD_EXTMOD),)
832# Objects we will link into vmlinux / subdirs we need to visit
833core-y		:=
834drivers-y	:=
835libs-y		:= lib/
836endif # KBUILD_EXTMOD
837
838# The all: target is the default when no target is given on the
839# command line.
840# This allow a user to issue only 'make' to build a kernel including modules
841# Defaults to vmlinux, but the arch makefile usually adds further targets
842all: vmlinux
843
844# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
845ifdef CONFIG_FUNCTION_TRACER
846  CC_FLAGS_FTRACE := -pg
847endif
848
849ifdef CONFIG_TRACEPOINTS
850# To check for unused tracepoints (tracepoints that are defined but never
851# called), run with:
852#
853# make UT=1
854#
855# Each unused tracepoints can take up to 5KB of memory in the running kernel.
856# It is best to remove any that are not used.
857#
858# This command line option will be removed when all current unused
859# tracepoints are removed.
860
861ifeq ("$(origin UT)", "command line")
862  WARN_ON_UNUSED_TRACEPOINTS := $(UT)
863endif
864endif # CONFIG_TRACEPOINTS
865
866export WARN_ON_UNUSED_TRACEPOINTS
867
868# Per-version Rust flags. These are like `rust_common_flags`, but may
869# depend on the Rust compiler version (e.g. using `rustc-min-version`).
870#
871# `-Aclippy::precedence`: the lint was extended in Rust 1.85.0 to
872# include bitmasking and shift operations. However, because it generated
873# many hits, in Rust 1.86.0 it was split into a new `precedence_bits`
874# lint which is not enabled by default.
875rust_common_flags_per_version := \
876    $(if $(call rustc-min-version,108600),,-Aclippy::precedence)
877
878rust_common_flags += $(rust_common_flags_per_version)
879KBUILD_HOSTRUSTFLAGS += $(rust_common_flags_per_version) $(HOSTRUSTFLAGS)
880KBUILD_RUSTFLAGS += $(rust_common_flags_per_version)
881
882include $(srctree)/arch/$(SRCARCH)/Makefile
883
884ifdef need-config
885ifdef may-sync-config
886# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
887# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
888# because some architectures define CROSS_COMPILE there.
889include include/config/auto.conf.cmd
890
891$(KCONFIG_CONFIG):
892	@echo >&2 '***'
893	@echo >&2 '*** Configuration file "$@" not found!'
894	@echo >&2 '***'
895	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
896	@echo >&2 '*** "make menuconfig" or "make xconfig").'
897	@echo >&2 '***'
898	@/bin/false
899
900# The actual configuration files used during the build are stored in
901# include/generated/ and include/config/. Update them if .config is newer than
902# include/config/auto.conf (which mirrors .config).
903#
904# This exploits the 'multi-target pattern rule' trick.
905# The syncconfig should be executed only once to make all the targets.
906# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
907#
908# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
909# so you cannot notice that Kconfig is waiting for the user input.
910%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
911	$(Q)$(kecho) "  SYNC    $@"
912	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
913else # !may-sync-config
914# External modules and some install targets need include/generated/autoconf.h
915# and include/config/auto.conf but do not care if they are up-to-date.
916# Use auto.conf to show the error message
917
918checked-configs := $(addprefix $(objtree)/, include/generated/autoconf.h include/generated/rustc_cfg include/config/auto.conf)
919missing-configs := $(filter-out $(wildcard $(checked-configs)), $(checked-configs))
920
921ifdef missing-configs
922PHONY += $(objtree)/include/config/auto.conf
923
924$(objtree)/include/config/auto.conf:
925	@echo   >&2 '***'
926	@echo   >&2 '***  ERROR: Kernel configuration is invalid. The following files are missing:'
927	@printf >&2 '***    - %s\n' $(missing-configs)
928	@echo   >&2 '***  Run "make oldconfig && make prepare" on kernel source to fix it.'
929	@echo   >&2 '***'
930	@/bin/false
931endif
932
933endif # may-sync-config
934endif # need-config
935
936KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
937
938ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
939KBUILD_CFLAGS += -O2
940KBUILD_RUSTFLAGS += -Copt-level=2
941else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
942KBUILD_CFLAGS += -Os
943KBUILD_RUSTFLAGS += -Copt-level=s
944endif
945
946# Always set `debug-assertions` and `overflow-checks` because their default
947# depends on `opt-level` and `debug-assertions`, respectively.
948KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
949KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
950
951# Tell gcc to never replace conditional load with a non-conditional one
952ifdef CONFIG_CC_IS_GCC
953# gcc-10 renamed --param=allow-store-data-races=0 to
954# -fno-allow-store-data-races.
955KBUILD_CFLAGS	+= $(CONFIG_CC_OPT_ALLOW_STORE_DATA_RACES_PARAM)
956KBUILD_CFLAGS	+= $(CONFIG_CC_OPT_NO_ALLOW_STORE_DATA_RACES)
957endif
958
959ifdef CONFIG_READABLE_ASM
960# Disable optimizations that make assembler listings hard to read.
961# reorder blocks reorders the control in the function
962# ipa clone creates specialized cloned functions
963# partial inlining inlines only parts of functions
964KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
965endif
966
967stackp-flags-y                                    := -fno-stack-protector
968stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
969stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
970
971KBUILD_CFLAGS += $(stackp-flags-y)
972
973ifdef CONFIG_FRAME_POINTER
974KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
975KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
976# Work around rustc bug on compilers without
977# https://github.com/rust-lang/rust/pull/156980.
978KBUILD_RUSTFLAGS += $(if $(call rustc-min-version,109800),,-Zllvm_module_flag=frame-pointer:u32:2:max)
979else
980# Some targets (ARM with Thumb2, for example), can't be built with frame
981# pointers.  For those, we don't have FUNCTION_TRACER automatically
982# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
983# incompatible with -fomit-frame-pointer with current GCC, so we don't use
984# -fomit-frame-pointer with FUNCTION_TRACER.
985# In the Rust target specification, "frame-pointer" is set explicitly
986# to "may-omit".
987ifndef CONFIG_FUNCTION_TRACER
988KBUILD_CFLAGS	+= -fomit-frame-pointer
989endif
990endif
991
992# Initialize all stack variables with a 0xAA pattern.
993ifdef CONFIG_INIT_STACK_ALL_PATTERN
994KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
995endif
996
997# Initialize all stack variables with a zero value.
998ifdef CONFIG_INIT_STACK_ALL_ZERO
999KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
1000ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
1001# https://github.com/llvm/llvm-project/issues/44842
1002CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
1003export CC_AUTO_VAR_INIT_ZERO_ENABLER
1004KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
1005endif
1006endif
1007
1008ifdef CONFIG_KMALLOC_PARTITION_TYPED
1009# KMALLOC_PARTITION_CACHES_NR + 1
1010KBUILD_CFLAGS	+= -falloc-token-max=16
1011endif
1012
1013ifdef CONFIG_CC_IS_CLANG
1014ifdef CONFIG_CC_HAS_COUNTED_BY_PTR
1015KBUILD_CFLAGS	+= -fexperimental-late-parse-attributes
1016endif
1017endif
1018
1019# Explicitly clear padding bits during variable initialization
1020KBUILD_CFLAGS += $(CONFIG_CC_OPT_ZERO_INIT_PADDING_BITS)
1021
1022# While VLAs have been removed, GCC produces unreachable stack probes
1023# for the randomize_kstack_offset feature. Disable it for all compilers.
1024# Probed here rather than in Kconfig as clang only accepts it for some
1025# sub-targets, so the architecture's flags matter.
1026KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
1027
1028# Get details on warnings generated due to GCC value tracking.
1029KBUILD_CFLAGS	+= $(CONFIG_CC_OPT_DIAGNOSTICS_SHOW_CONTEXT)
1030
1031# Show inlining notes for __attribute__((warning/error)) call chains.
1032# GCC supports this unconditionally while Clang 23+ provides a flag.
1033KBUILD_CFLAGS	+= $(CONFIG_CC_OPT_DIAGNOSTICS_SHOW_INLINING_CHAIN)
1034
1035# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
1036ifdef CONFIG_ZERO_CALL_USED_REGS
1037KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
1038endif
1039
1040ifdef CONFIG_FUNCTION_TRACER
1041ifdef CONFIG_FTRACE_MCOUNT_USE_CC
1042  CC_FLAGS_FTRACE	+= -mrecord-mcount
1043  ifdef CONFIG_HAVE_NOP_MCOUNT
1044    ifdef CONFIG_CC_HAS_MNOP_MCOUNT
1045      CC_FLAGS_FTRACE	+= -mnop-mcount
1046      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
1047    endif
1048  endif
1049endif
1050ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
1051  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
1052    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
1053  endif
1054endif
1055ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
1056  ifdef CONFIG_HAVE_C_RECORDMCOUNT
1057    BUILD_C_RECORDMCOUNT := y
1058    export BUILD_C_RECORDMCOUNT
1059  endif
1060endif
1061ifdef CONFIG_HAVE_FENTRY
1062  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
1063  ifeq ($(call cc-option-yn, -mfentry),y)
1064    CC_FLAGS_FTRACE	+= -mfentry
1065    CC_FLAGS_USING	+= -DCC_USING_FENTRY
1066  endif
1067endif
1068export CC_FLAGS_FTRACE
1069KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
1070KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
1071endif
1072
1073# We trigger additional mismatches with less inlining
1074ifdef CONFIG_DEBUG_SECTION_MISMATCH
1075KBUILD_CFLAGS += -fno-inline-functions-called-once
1076endif
1077
1078# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
1079ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
1080KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
1081KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
1082LDFLAGS_vmlinux += --gc-sections
1083endif
1084
1085ifdef CONFIG_SHADOW_CALL_STACK
1086ifndef CONFIG_DYNAMIC_SCS
1087CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
1088KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
1089KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
1090endif
1091export CC_FLAGS_SCS
1092endif
1093
1094ifdef CONFIG_RUST_INLINE_HELPERS
1095# `rustc` normally emits traps for unreachable paths during code generation.
1096# With inline helpers, Clang performs code generation from the linked bitcode
1097# instead, so request the same behavior explicitly. Otherwise `objtool` may
1098# follow an impossible Rust path into the next function.
1099CC_FLAGS_RUST_INLINE_HELPERS := -mllvm -trap-unreachable \
1100				-mllvm -no-trap-after-noreturn
1101export CC_FLAGS_RUST_INLINE_HELPERS
1102endif
1103
1104ifdef CONFIG_LTO_CLANG
1105ifdef CONFIG_LTO_CLANG_FULL
1106CC_FLAGS_LTO	:= -flto
1107else
1108CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
1109
1110# These LLVM options were initially added with only in-process ThinLTO
1111# support, so avoid distributed ThinLTO support for now.
1112ifdef CONFIG_LTO_CLANG_THIN
1113KBUILD_LDFLAGS += $(call ld-option,--lto-whole-program-visibility -mllvm -always-rename-promoted-locals=false)
1114endif
1115endif
1116CC_FLAGS_LTO	+= -fvisibility=hidden
1117
1118# Limit inlining across translation units to reduce binary size
1119KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
1120endif
1121
1122ifdef CONFIG_LTO
1123KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1124KBUILD_AFLAGS	+= -fno-lto
1125export CC_FLAGS_LTO
1126endif
1127
1128ifdef CONFIG_CFI
1129CC_FLAGS_CFI	:= -fsanitize=kcfi
1130ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
1131	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
1132endif
1133ifdef CONFIG_FINEIBT_BHI
1134	CC_FLAGS_CFI	+= -fsanitize-kcfi-arity
1135endif
1136ifdef CONFIG_RUST
1137	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
1138	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
1139	# Disable function merging as LLVM incorrectly merges functions with different KCFI types.
1140	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers -Zmerge-functions=disabled
1141	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
1142	export RUSTC_FLAGS_CFI
1143endif
1144KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1145export CC_FLAGS_CFI
1146endif
1147
1148# Architectures can define flags to add/remove for floating-point support
1149CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
1150export CC_FLAGS_FPU
1151export CC_FLAGS_NO_FPU
1152
1153ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1154# Set the minimal function alignment. Use the newer GCC option
1155# -fmin-function-alignment if it is available, or fall back to -falign-functions.
1156# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
1157ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
1158KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
1159else
1160KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1161endif
1162endif
1163
1164# arch Makefile may override CC so keep this after arch Makefile is included
1165NOSTDINC_FLAGS += -nostdinc
1166
1167# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
1168# the kernel uses only C99 flexible arrays for dynamically sized trailing
1169# arrays. Enforce this for everything that may examine structure sizes and
1170# perform bounds checking.
1171KBUILD_CFLAGS += $(CONFIG_CC_OPT_STRICT_FLEX_ARRAYS)
1172
1173# disable invalid "can't wrap" optimizations for signed / pointers
1174KBUILD_CFLAGS	+= -fno-strict-overflow
1175
1176# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1177KBUILD_CFLAGS  += -fno-stack-check
1178
1179# conserve stack if available
1180ifdef CONFIG_CC_IS_GCC
1181KBUILD_CFLAGS   += -fconserve-stack
1182endif
1183
1184# Ensure compilers do not transform certain loops into calls to wcslen()
1185KBUILD_CFLAGS += -fno-builtin-wcslen
1186
1187# change __FILE__ to the relative path to the source directory
1188ifdef building_out_of_srctree
1189CFLAGS_PREFIX_MAP := -fmacro-prefix-map=$(srcroot)/=
1190KBUILD_CPPFLAGS += $(CFLAGS_PREFIX_MAP)
1191KBUILD_USERCFLAGS += $(CFLAGS_PREFIX_MAP)
1192KBUILD_HOSTCFLAGS += $(CFLAGS_PREFIX_MAP)
1193ifeq ($(call rustc-option-yn, --remap-path-scope=macro),y)
1194KBUILD_RUSTFLAGS += --remap-path-prefix=$(srcroot)/= --remap-path-scope=macro
1195endif
1196endif
1197
1198# include additional Makefiles when needed
1199include-y			:= scripts/Makefile.warn
1200include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1201include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1202include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1203include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1204include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1205include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1206include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1207include-$(CONFIG_GCOV_KERNEL)	+= scripts/Makefile.gcov
1208include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1209include-$(CONFIG_KSTACK_ERASE)	+= scripts/Makefile.kstack_erase
1210include-$(CONFIG_AUTOFDO_CLANG)	+= scripts/Makefile.autofdo
1211include-$(CONFIG_PROPELLER_CLANG)	+= scripts/Makefile.propeller
1212include-$(CONFIG_WARN_CONTEXT_ANALYSIS) += scripts/Makefile.context-analysis
1213include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1214
1215include $(addprefix $(srctree)/, $(include-y))
1216
1217# scripts/Makefile.gcc-plugins is intentionally included last.
1218# Do not add $(call cc-option,...) below this line. When you build the kernel
1219# from the clean source tree, the GCC plugins do not exist at this point.
1220
1221# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1222KBUILD_CPPFLAGS += $(KCPPFLAGS)
1223KBUILD_AFLAGS   += $(KAFLAGS)
1224KBUILD_CFLAGS   += $(KCFLAGS)
1225KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1226
1227KBUILD_LDFLAGS_MODULE += --build-id=sha1
1228LDFLAGS_vmlinux += --build-id=sha1
1229
1230# Specific code, such as outlined KASAN checks, may be placed in
1231# COMDAT-deduplicated sections. Use --force-group-allocation to resolve these
1232# groups when linking modules. The option is available from ld.bfd 2.29 and
1233# ld.lld 19.1.0.
1234KBUILD_LDFLAGS_MODULE += $(CONFIG_LD_OPT_FORCE_GROUP_ALLOCATION)
1235
1236KBUILD_LDFLAGS	+= -z noexecstack
1237ifeq ($(CONFIG_LD_IS_BFD),y)
1238KBUILD_LDFLAGS	+= $(CONFIG_LD_OPT_NO_WARN_RWX_SEGMENTS)
1239endif
1240
1241ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1242LDFLAGS_vmlinux	+= -X
1243endif
1244
1245ifeq ($(CONFIG_RELR),y)
1246# ld.lld before 15 did not support -z pack-relative-relocs.
1247LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1248endif
1249
1250# We never want expected sections to be placed heuristically by the
1251# linker. All sections should be explicitly named in the linker script.
1252ifdef CONFIG_LD_ORPHAN_WARN
1253LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1254endif
1255
1256# --emit-relocs is added by scripts/link-vmlinux.sh, for the final link only.
1257ifneq ($(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS),)
1258LDFLAGS_vmlinux	+= --discard-none
1259endif
1260
1261# Align the architecture of userspace programs with the kernel
1262USERFLAGS_FROM_KERNEL := --target=%
1263
1264ifdef CONFIG_ARCH_USERFLAGS
1265KBUILD_USERCFLAGS += $(CONFIG_ARCH_USERFLAGS)
1266KBUILD_USERLDFLAGS += $(CONFIG_ARCH_USERFLAGS)
1267else
1268# If not overridden also inherit the bit size
1269USERFLAGS_FROM_KERNEL += -m32 -m64
1270endif
1271
1272KBUILD_USERCFLAGS  += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1273KBUILD_USERLDFLAGS += $(filter $(USERFLAGS_FROM_KERNEL), $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1274
1275# userspace programs are linked via the compiler, use the correct linker
1276ifdef CONFIG_CC_IS_CLANG
1277KBUILD_USERLDFLAGS += --ld-path=$(LD)
1278endif
1279
1280# make the checker run with the right architecture
1281CHECKFLAGS += --arch=$(ARCH)
1282
1283# insure the checker run with the right endianness
1284CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1285
1286# the checker needs the correct machine size
1287CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1288
1289# Validate the checker is available and functional
1290ifneq ($(KBUILD_CHECKSRC), 0)
1291  ifneq ($(shell $(srctree)/scripts/checker-valid.sh $(CHECK) $(CHECKFLAGS)), 1)
1292    $(warning C=$(KBUILD_CHECKSRC) specified, but $(CHECK) is not available or not up to date)
1293    KBUILD_CHECKSRC = 0
1294  endif
1295endif
1296
1297# Default kernel image to build when no specific target is given.
1298# KBUILD_IMAGE may be overruled on the command line or
1299# set in the environment
1300# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1301# this default value
1302export KBUILD_IMAGE ?= vmlinux
1303
1304#
1305# INSTALL_PATH specifies where to place the updated kernel and system map
1306# images. Default is /boot, but you can set it to other values
1307export	INSTALL_PATH ?= /boot
1308
1309#
1310# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1311# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1312# an argument if needed. Otherwise it defaults to the kernel install path
1313#
1314export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1315
1316#
1317# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1318# relocations required by build roots.  This is not defined in the
1319# makefile but the argument can be passed to make if needed.
1320#
1321
1322MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1323export MODLIB
1324
1325PHONY += prepare0
1326
1327ifeq ($(KBUILD_EXTMOD),)
1328
1329build-dir	:= .
1330clean-dirs	:= $(sort . Documentation \
1331		     $(patsubst %/,%,$(filter %/, $(core-) \
1332			$(drivers-) $(libs-))))
1333
1334export ARCH_CORE	:= $(core-y)
1335export ARCH_LIB		:= $(filter %/, $(libs-y))
1336export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1337# Externally visible symbols (used by link-vmlinux.sh)
1338
1339KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1340KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1341
1342export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1343export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1344
1345ifdef CONFIG_TRIM_UNUSED_KSYMS
1346# For the kernel to actually contain only the needed exported symbols,
1347# we have to build modules as well to determine what those symbols are.
1348KBUILD_MODULES := y
1349endif
1350
1351PHONY += vmlinux_a
1352vmlinux_a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1353	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_a
1354
1355vmlinux.a: vmlinux_a
1356	@:
1357
1358PHONY += vmlinux_o
1359vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1360	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1361
1362vmlinux.o: vmlinux_o
1363	@:
1364
1365PHONY += vmlinux
1366# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1367# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1368# unrelated; the decompressors just happen to have the same base name,
1369# arch/*/boot/compressed/vmlinux.
1370# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1371#
1372# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1373#   https://savannah.gnu.org/bugs/?61463
1374# For Make > 4.4, the following simple code will work:
1375#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1376vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1377vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1378vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1379	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1380
1381# The actual objects are generated when descending,
1382# make sure no implicit rule kicks in
1383$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1384
1385ifeq ($(origin KERNELRELEASE),file)
1386filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1387else
1388filechk_kernel.release = echo $(KERNELRELEASE)
1389endif
1390
1391# Store (new) KERNELRELEASE string in include/config/kernel.release
1392include/config/kernel.release: FORCE
1393	$(call filechk,kernel.release)
1394
1395# Additional helpers built in scripts/
1396# Carefully list dependencies so we do not try to build scripts twice
1397# in parallel
1398PHONY += scripts
1399scripts: scripts_basic scripts_dtc
1400	$(Q)$(MAKE) $(build)=$(@)
1401
1402# Things we need to do before we recursively start building the kernel
1403# or the modules are listed in "prepare".
1404# A multi level approach is used. prepareN is processed before prepareN-1.
1405# archprepare is used in arch Makefiles and when processed asm symlink,
1406# version.h and scripts_basic is processed / created.
1407
1408PHONY += prepare archprepare
1409
1410archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1411	asm-generic $(version_h) include/generated/utsrelease.h \
1412	include/generated/compile.h include/generated/autoconf.h \
1413	include/generated/rustc_cfg remove-stale-files
1414
1415prepare0: archprepare
1416	$(Q)$(MAKE) $(build)=scripts/mod
1417	$(Q)$(MAKE) $(build)=. prepare
1418
1419# All the preparing..
1420prepare: prepare0
1421ifdef CONFIG_RUST
1422	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1423	$(Q)$(MAKE) $(build)=rust
1424endif
1425
1426PHONY += remove-stale-files
1427remove-stale-files:
1428	$(Q)$(srctree)/scripts/remove-stale-files
1429
1430# Support for using generic headers in asm-generic
1431asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1432
1433PHONY += asm-generic uapi-asm-generic
1434asm-generic: uapi-asm-generic
1435	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1436	generic=include/asm-generic
1437uapi-asm-generic:
1438	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1439	generic=include/uapi/asm-generic
1440
1441# Generate some files
1442# ---------------------------------------------------------------------------
1443
1444# KERNELRELEASE can change from a few different places, meaning version.h
1445# needs to be updated, so this check is forced on all builds
1446
1447uts_len := 64
1448define filechk_utsrelease.h
1449	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1450	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1451	  exit 1;                                                         \
1452	fi;                                                               \
1453	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1454endef
1455
1456define filechk_version.h
1457	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1458		echo \#define LINUX_VERSION_CODE $(shell                 \
1459		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1460	else                                                             \
1461		echo \#define LINUX_VERSION_CODE $(shell                 \
1462		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1463	fi;                                                              \
1464	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1465	((c) > 255 ? 255 : (c)))';                                       \
1466	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1467	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1468	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1469endef
1470
1471$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1472$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1473$(version_h): FORCE
1474	$(call filechk,version.h)
1475
1476include/generated/utsrelease.h: include/config/kernel.release FORCE
1477	$(call filechk,utsrelease.h)
1478
1479filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1480	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1481
1482include/generated/compile.h: FORCE
1483	$(call filechk,compile.h)
1484
1485PHONY += headerdep
1486headerdep:
1487	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1488	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1489
1490# ---------------------------------------------------------------------------
1491# Kernel headers
1492
1493#Default location for installed headers
1494export INSTALL_HDR_PATH = $(objtree)/usr
1495
1496quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1497      cmd_headers_install = \
1498	mkdir -p $(INSTALL_HDR_PATH); \
1499	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1500	usr/include $(INSTALL_HDR_PATH)
1501
1502PHONY += headers_install
1503headers_install: headers
1504	$(call cmd,headers_install)
1505
1506PHONY += archheaders archscripts
1507
1508hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1509
1510PHONY += headers
1511headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders
1512ifdef HEADER_ARCH
1513	$(Q)$(MAKE) -f $(srctree)/Makefile HEADER_ARCH= SRCARCH=$(HEADER_ARCH) headers
1514else
1515	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1516	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1517endif
1518
1519ifdef CONFIG_HEADERS_INSTALL
1520prepare: headers
1521endif
1522
1523PHONY += scripts_gen_init_cpio
1524scripts_gen_init_cpio: scripts_basic
1525	$(Q)$(MAKE) $(build)=scripts scripts/gen_init_cpio
1526
1527PHONY += scripts_unifdef
1528scripts_unifdef: scripts_basic
1529	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1530
1531PHONY += scripts_gen_packed_field_checks
1532scripts_gen_packed_field_checks: scripts_basic
1533	$(Q)$(MAKE) $(build)=scripts scripts/gen_packed_field_checks
1534
1535# ---------------------------------------------------------------------------
1536# Header check
1537
1538# Check the headers in HEADER_CHECK=(headers|dirs)
1539PHONY += headercheck
1540
1541ifneq ($(HEADER_CHECK),)
1542
1543header-check-dirs := $(filter-out %.h,$(HEADER_CHECK))
1544header-check-files := $(filter %.h,$(HEADER_CHECK)) $(if $(header-check-dirs),$(shell cd $(srctree) && find $(header-check-dirs) -name '*.h' 2>/dev/null))
1545header-check-targets := $(patsubst %.h,%.header-check,$(sort $(header-check-files)))
1546
1547headercheck:
1548	$(if $(header-check-targets),,$(error $@ found no headers in HEADER_CHECK="$(HEADER_CHECK)"))
1549	$(Q)$(MAKE) $(header-check-targets)
1550else
1551headercheck:
1552	$(error $@ requires HEADER_CHECK=(headers|dirs))
1553endif
1554
1555# ---------------------------------------------------------------------------
1556# Install
1557
1558# Many distributions have the custom install script, /sbin/installkernel.
1559# If DKMS is installed, 'make install' will eventually recurse back
1560# to this Makefile to build and install external modules.
1561# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1562
1563quiet_cmd_install = INSTALL $(INSTALL_PATH)
1564      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1565
1566# ---------------------------------------------------------------------------
1567# vDSO install
1568
1569PHONY += vdso_install
1570vdso_install: export INSTALL_FILES = $(vdso-install-y)
1571vdso_install:
1572	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1573
1574# ---------------------------------------------------------------------------
1575# Tools
1576
1577ifdef CONFIG_OBJTOOL
1578prepare: tools/objtool
1579endif
1580
1581ifdef CONFIG_BPF
1582ifdef CONFIG_DEBUG_INFO_BTF
1583prepare: tools/bpf/resolve_btfids
1584endif
1585endif
1586
1587# tools/bootconfig renders the embedded bootconfig into a cmdline at build time.
1588ifdef CONFIG_CMDLINE_FROM_BOOTCONFIG
1589prepare: tools/bootconfig
1590endif
1591
1592# tools/bootconfig is run on the build host during prepare, so force a host
1593# binary here; its own Makefile keeps $(CC) for standalone and cross builds.
1594# CROSS_COMPILE= is cleared so tools/scripts/Makefile.include does not inject
1595# the target's --target=/--sysroot= flags into the host clang invocation under
1596# LLVM=1 cross builds (which would produce a target binary that fails to exec).
1597tools/bootconfig: export CC := $(HOSTCC)
1598tools/bootconfig: FORCE
1599	$(Q)mkdir -p $(objtree)/tools
1600	$(Q)$(MAKE) O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ \
1601		bootconfig CROSS_COMPILE=
1602
1603# The tools build system is not a part of Kbuild and tends to introduce
1604# its own unique issues. If you need to integrate a new tool into Kbuild,
1605# please consider locating that tool outside the tools/ tree and using the
1606# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1607# here. See Documentation/kbuild/makefiles.rst for details.
1608
1609PHONY += resolve_btfids_clean
1610
1611resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1612
1613# tools/bpf/resolve_btfids directory might not exist
1614# in output directory, skip its clean in that case
1615resolve_btfids_clean:
1616ifneq ($(wildcard $(resolve_btfids_O)),)
1617	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1618endif
1619
1620PHONY += objtool_clean objtool_mrproper
1621
1622objtool_O = $(abspath $(objtree))/tools/objtool
1623
1624objtool_clean objtool_mrproper:
1625ifneq ($(wildcard $(objtool_O)),)
1626	$(Q)$(MAKE) -sC $(abs_srctree)/tools/objtool O=$(objtool_O) srctree=$(abs_srctree) $(patsubst objtool_%,%,$@)
1627endif
1628
1629PHONY += bootconfig_clean
1630
1631bootconfig_O = $(abspath $(objtree))/tools/bootconfig
1632
1633bootconfig_clean:
1634ifneq ($(wildcard $(bootconfig_O)),)
1635	$(Q)$(MAKE) -sC $(srctree)/tools/bootconfig O=$(bootconfig_O) clean
1636endif
1637
1638tools/: FORCE
1639	$(Q)mkdir -p $(objtree)/tools
1640	$(Q)$(MAKE) O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1641
1642tools/%: FORCE
1643	$(Q)mkdir -p $(objtree)/tools
1644	$(Q)$(MAKE) O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1645
1646# ---------------------------------------------------------------------------
1647# Kernel selftest
1648
1649PHONY += kselftest
1650kselftest: headers
1651	$(Q)unset sub_make_done; $(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1652
1653kselftest-%: headers FORCE
1654	$(Q)unset sub_make_done; $(MAKE) -C $(srctree)/tools/testing/selftests $*
1655
1656PHONY += kselftest-merge
1657kselftest-merge:
1658	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1659	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1660		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1661	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1662
1663# ---------------------------------------------------------------------------
1664# Devicetree files
1665
1666ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1667dtstree := arch/$(SRCARCH)/boot/dts
1668endif
1669
1670dtbindingtree := Documentation/devicetree/bindings
1671
1672%.yaml: dtbs_prepare
1673	$(Q)$(MAKE) $(build)=$(dtbindingtree) \
1674		    $(dtbindingtree)/$(patsubst %.yaml,%.example.dtb,$@) dt_binding_check_one
1675
1676ifneq ($(dtstree),)
1677
1678%.dtb: dtbs_prepare
1679	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1680
1681%.dtbo: dtbs_prepare
1682	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1683
1684PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1685dtbs: dtbs_prepare
1686	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1687
1688# include/config/kernel.release is actually needed when installing DTBs because
1689# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1690# dtbs_install depend on it as dtbs_install may run as root.
1691dtbs_prepare: include/config/kernel.release scripts_dtc
1692
1693ifneq ($(filter dtbs_check %.yaml, $(MAKECMDGOALS)),)
1694export CHECK_DTBS=y
1695endif
1696
1697ifneq ($(CHECK_DTBS),)
1698dtbs_prepare: dt_binding_schemas
1699endif
1700
1701dtbs_check: dtbs
1702
1703dtbs_install:
1704	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1705
1706ifdef CONFIG_OF_EARLY_FLATTREE
1707all: dtbs
1708endif
1709
1710ifdef CONFIG_GENERIC_BUILTIN_DTB
1711vmlinux: dtbs
1712endif
1713
1714endif
1715
1716PHONY += scripts_dtc
1717scripts_dtc: scripts_basic
1718	$(Q)$(MAKE) $(build)=scripts/dtc
1719
1720ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1721export CHECK_DTBS=y
1722endif
1723
1724PHONY += dt_binding_check dt_binding_schemas
1725dt_binding_check: dt_binding_schemas scripts_dtc
1726	$(Q)$(MAKE) $(build)=$(dtbindingtree) $@
1727
1728dt_binding_schemas:
1729	$(Q)$(MAKE) $(build)=$(dtbindingtree)
1730
1731PHONY += dt_compatible_check
1732dt_compatible_check: dt_binding_schemas
1733	$(Q)$(MAKE) $(build)=$(dtbindingtree) $@
1734
1735PHONY += dt_style_selftest
1736dt_style_selftest:
1737	$(Q)$(srctree)/scripts/dtc/dt-style-selftest/run.sh
1738
1739# ---------------------------------------------------------------------------
1740# Modules
1741
1742ifdef CONFIG_MODULES
1743
1744# By default, build modules as well
1745
1746all: modules
1747
1748# When we're building modules with modversions, we need to consider
1749# the built-in objects during the descend as well, in order to
1750# make sure the checksums are up to date before we record them.
1751ifdef CONFIG_MODVERSIONS
1752  KBUILD_BUILTIN := y
1753endif
1754
1755# Build modules
1756#
1757
1758# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1759# is an exception.
1760ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1761KBUILD_BUILTIN := y
1762modules: vmlinux
1763endif
1764
1765modules: modules_prepare
1766
1767# Target to prepare building external modules
1768modules_prepare: prepare
1769	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1770
1771endif # CONFIG_MODULES
1772
1773###
1774# Cleaning is done on three levels.
1775# make clean     Delete most generated files
1776#                Leave enough to build external modules
1777# make mrproper  Delete the current configuration, and all generated files
1778# make distclean Remove editor backup files, patch leftover files and the like
1779
1780# Directories & files removed with 'make clean'
1781CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1782	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1783	       modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \
1784	       vmlinux.BTF.inline \
1785	       vmlinux.thinlto-index builtin.order \
1786	       compile_commands.json rust/test \
1787	       rust-project.json .vmlinux.objs .vmlinux.export.c \
1788	       .builtin-dtbs-list .builtin-dtbs.S sbom-*.spdx.json
1789
1790# Directories & files removed with 'make mrproper'
1791MRPROPER_FILES += include/config include/generated          \
1792		  arch/$(SRCARCH)/include/generated .objdiff \
1793		  debian snap tar-install PKGBUILD pacman \
1794		  .config .config.old .version \
1795		  Module.symvers \
1796		  certs/signing_key.pem \
1797		  certs/x509.genkey \
1798		  vmlinux-gdb.py \
1799		  rpmbuild \
1800		  rust/libmacros.so rust/libmacros.dylib \
1801		  rust/libpin_init_internal.so rust/libpin_init_internal.dylib \
1802		  rust/libzerocopy_derive.so rust/libzerocopy_derive.dylib
1803
1804# clean - Delete most, but leave enough to build external modules
1805#
1806clean: private rm-files := $(CLEAN_FILES)
1807
1808PHONY += archclean vmlinuxclean
1809
1810vmlinuxclean:
1811	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1812	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1813
1814clean: archclean vmlinuxclean resolve_btfids_clean objtool_clean bootconfig_clean
1815
1816# mrproper - Delete all generated files, including .config
1817#
1818mrproper: private rm-files := $(MRPROPER_FILES)
1819mrproper-dirs      := $(addprefix _mrproper_,scripts)
1820
1821PHONY += $(mrproper-dirs) mrproper
1822$(mrproper-dirs):
1823	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1824
1825mrproper: clean objtool_mrproper $(mrproper-dirs)
1826	$(call cmd,rmfiles)
1827	@find . $(RCS_FIND_IGNORE) \
1828		\( -name '*.rmeta' \) \
1829		-type f -print | xargs rm -f
1830
1831# distclean
1832#
1833PHONY += distclean
1834
1835distclean: mrproper
1836	@find . $(RCS_FIND_IGNORE) \
1837		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1838		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1839		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1840		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1841		-type f -print | xargs rm -f
1842
1843
1844# Packaging of the kernel to various formats
1845# ---------------------------------------------------------------------------
1846
1847modules-cpio-pkg: scripts_gen_init_cpio
1848
1849%src-pkg: FORCE
1850	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1851%pkg: include/config/kernel.release FORCE
1852	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1853
1854# Brief documentation of the typical targets used
1855# ---------------------------------------------------------------------------
1856
1857boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1858boards := $(sort $(notdir $(boards)))
1859board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1860board-dirs := $(sort $(notdir $(board-dirs:/=)))
1861
1862PHONY += help
1863help:
1864	@echo  'Cleaning targets:'
1865	@echo  '  clean		  - Remove most generated files but keep the config and'
1866	@echo  '                    enough build support to build external modules'
1867	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1868	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1869	@echo  ''
1870	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1871	@echo  ''
1872	@echo  'Other generic targets:'
1873	@echo  '  all		  - Build all targets marked with [*]'
1874	@echo  '* vmlinux	  - Build the bare kernel'
1875	@echo  '* modules	  - Build all modules'
1876	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1877	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1878	@echo  '  dir/            - Build all files in dir and below'
1879	@echo  '  dir/file.[ois]  - Build specified target only'
1880	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1881	@echo  '                    (requires compiler support for LLVM assembly generation)'
1882	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1883	@echo  '                    (requires a recent binutils and recent build (System.map))'
1884	@echo  '  dir/file.ko     - Build module including final link'
1885	@echo  '  modules_prepare - Set up for building external modules'
1886	@echo  '  tags/TAGS	  - Generate tags file for editors'
1887	@echo  '  cscope	  - Generate cscope index'
1888	@echo  '  gtags           - Generate GNU GLOBAL index'
1889	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1890	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1891	@echo  '  image_name	  - Output the image name (use with make -s)'
1892	@echo  '  headers	  - Build ready-to-install UAPI headers in usr/include'
1893	@echo  '  headers_install - Install sanitised kernel UAPI headers to INSTALL_HDR_PATH'; \
1894	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1895	 echo  ''
1896	@echo  'Static analysers:'
1897	@echo  '  checkstack        - Generate a list of stack hogs and consider all functions'
1898	@echo  '                      with a stack size larger than MINSTACKSIZE (default: 100)'
1899	@echo  '  versioncheck      - Sanity check on version.h usage'
1900	@echo  '  includecheck      - Check for duplicate included header files'
1901	@echo  '  headerdep         - Detect inclusion cycles in headers'
1902	@echo  '  headercheck       - Check headers in HEADER_CHECK=(headers|dirs) are'
1903	@echo  '                      self-contained, have header guards, and pass kernel-doc.'
1904	@echo  '  coccicheck        - Check with Coccinelle'
1905	@echo  '  kconfig-sym-check - Check for dangling Kconfig symbol references'
1906	@echo  '  clang-analyzer    - Check with clang static analyzer'
1907	@echo  '  clang-tidy        - Check with clang-tidy'
1908	@echo  ''
1909	@echo  'Tools:'
1910	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1911	@echo  '  sbom            - Generate Software Bill of Materials'
1912	@echo  ''
1913	@echo  'Kernel selftest:'
1914	@echo  '  kselftest         - Build and run kernel selftest'
1915	@echo  '                      Build, install, and boot kernel before'
1916	@echo  '                      running kselftest on it'
1917	@echo  '                      Run as root for full coverage'
1918	@echo  '  kselftest-all     - Build kernel selftest'
1919	@echo  '  kselftest-install - Build and install kernel selftest'
1920	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1921	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1922	@echo  '		      kselftest to existing .config.'
1923	@echo  ''
1924	@echo  'Rust targets:'
1925	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1926	@echo  '		    available and, if not, explains why.'
1927	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1928	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1929	@echo  '		    is formatted, printing a diff otherwise.'
1930	@echo  '  rustdoc	  - Generate Rust documentation'
1931	@echo  '		    (requires kernel .config)'
1932	@echo  '  rusttest        - Runs the Rust tests'
1933	@echo  '                    (requires kernel .config; downloads external repos)'
1934	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1935	@echo  '		    (requires kernel .config)'
1936	@echo  '  dir/file.[os]   - Build specified target only'
1937	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1938	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1939	@echo  '                    The output is not intended to be compilable.'
1940	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1941	@echo  ''
1942	@$(if $(dtstree), \
1943		echo 'Devicetree:'; \
1944		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1945		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1946		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1947		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1948		echo '  dt_style_selftest  - Run dt-check-style fixture tests'; \
1949		echo '  dtbs_check         - Validate device tree source files';\
1950		echo '')
1951
1952	@echo 'Userspace tools targets:'
1953	@echo '  use "make tools/help"'
1954	@echo '  or  "cd tools; make help"'
1955	@echo  ''
1956	@echo  'Kernel packaging:'
1957	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1958	@echo  ''
1959	@echo  'Documentation targets:'
1960	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1961	@echo  ''
1962	@echo  'Architecture-specific targets ($(SRCARCH)):'
1963	@$(or $(archhelp),\
1964		echo '  No architecture-specific help defined for $(SRCARCH)')
1965	@echo  ''
1966	@$(if $(boards), \
1967		$(foreach b, $(boards), \
1968		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1969		echo '')
1970	@$(if $(board-dirs), \
1971		$(foreach b, $(board-dirs), \
1972		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1973		printf "  %-16s - Show all of the above\\n" help-boards; \
1974		echo '')
1975
1976	@echo  '  make V=n   [targets] 1: verbose build'
1977	@echo  '                       2: give reason for rebuild of target'
1978	@echo  '                       V=1 and V=2 can be combined with V=12'
1979	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1980	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1981	@echo  '                       (sparse by default)'
1982	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1983	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1984	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1985	@echo  '		1: warnings which may be relevant and do not occur too often'
1986	@echo  '		2: warnings which occur quite often but may still be relevant'
1987	@echo  '		3: more obscure warnings, can most likely be ignored'
1988	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1989	@echo  '		e: warnings are being treated as errors'
1990	@echo  '		Multiple levels can be combined with W=12 or W=123'
1991	@echo  '  make UT=1   [targets] Warn if a tracepoint is defined but not used.'
1992	@echo  '          [ This will be removed when all current unused tracepoints are eliminated. ]'
1993	@$(if $(dtstree), \
1994		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1995		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1996		)
1997	@echo  ''
1998	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1999	@echo  'For further info see the ./README file'
2000
2001
2002help-board-dirs := $(addprefix help-,$(board-dirs))
2003
2004help-boards: $(help-board-dirs)
2005
2006boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
2007
2008$(help-board-dirs): help-%:
2009	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
2010	@$(if $(boards-per-dir), \
2011		$(foreach b, $(boards-per-dir), \
2012		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
2013		echo '')
2014
2015
2016# Documentation targets
2017# ---------------------------------------------------------------------------
2018DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
2019	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs mandocs \
2020	       htmldocs-redirects testdocs
2021
2022PHONY += $(DOC_TARGETS)
2023$(DOC_TARGETS):
2024	$(Q)$(MAKE) $(build)=Documentation $@
2025
2026
2027# Rust targets
2028# ---------------------------------------------------------------------------
2029
2030# "Is Rust available?" target
2031PHONY += rustavailable
2032rustavailable:
2033	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
2034
2035# Documentation target
2036#
2037# Using the singular to avoid running afoul of `no-dot-config-targets`.
2038PHONY += rustdoc
2039rustdoc: prepare
2040	$(Q)$(MAKE) $(build)=rust $@
2041
2042# Testing target
2043PHONY += rusttest
2044rusttest: prepare
2045	$(Q)$(MAKE) $(build)=rust $@
2046
2047# Formatting targets
2048#
2049# Generated files as well as vendored crates are skipped.
2050PHONY += rustfmt rustfmtcheck
2051
2052rustfmt:
2053	$(Q)find $(srctree) $(RCS_FIND_IGNORE) \
2054		\( \
2055			-path $(srctree)/rust/proc-macro2 \
2056			-o -path $(srctree)/rust/quote \
2057			-o -path $(srctree)/rust/syn \
2058			-o -path $(srctree)/rust/zerocopy \
2059			-o -path $(srctree)/rust/zerocopy-derive \
2060		\) -prune -o \
2061		-type f -a -name '*.rs' -a ! -name '*generated*' -print \
2062		| xargs $(RUSTFMT) $(rustfmt_flags)
2063
2064rustfmtcheck: rustfmt_flags = --check
2065rustfmtcheck: rustfmt
2066
2067# Misc
2068# ---------------------------------------------------------------------------
2069
2070PHONY += misc-check
2071misc-check:
2072	$(Q)$(srctree)/scripts/misc-check
2073
2074all: misc-check
2075
2076PHONY += scripts_gdb
2077scripts_gdb: prepare0
2078	$(Q)$(MAKE) $(build)=scripts/gdb
2079	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
2080
2081ifdef CONFIG_GDB_SCRIPTS
2082all: scripts_gdb
2083endif
2084
2085else # KBUILD_EXTMOD
2086
2087filechk_kernel.release = echo $(KERNELRELEASE)
2088
2089###
2090# External module support.
2091# When building external modules the kernel used as basis is considered
2092# read-only, and no consistency checks are made and the make
2093# system is not used on the basis kernel. If updates are required
2094# in the basis kernel ordinary make commands (without M=...) must be used.
2095
2096# We are always building only modules.
2097KBUILD_BUILTIN :=
2098KBUILD_MODULES := y
2099
2100build-dir := .
2101
2102clean-dirs := .
2103clean: private rm-files := Module.symvers modules.nsdeps compile_commands.json
2104
2105PHONY += prepare
2106# now expand this into a simple variable to reduce the cost of shell evaluations
2107prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
2108prepare: PAHOLE_VERSION := $(PAHOLE_VERSION)
2109prepare:
2110	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
2111		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
2112		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
2113		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
2114	fi
2115	@if [ "$(PAHOLE_VERSION)" != "$(CONFIG_PAHOLE_VERSION)" ]; then \
2116		echo >&2 "warning: pahole version differs from the one used to build the kernel"; \
2117		echo >&2 "  The kernel was built with: $(CONFIG_PAHOLE_VERSION)"; \
2118		echo >&2 "  You are using:             $(PAHOLE_VERSION)"; \
2119	fi
2120
2121PHONY += help
2122help:
2123	@echo  '  Building external modules.'
2124	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
2125	@echo  ''
2126	@echo  '  modules         - default target, build the module(s)'
2127	@echo  '  modules_install - install the module'
2128	@echo  '  clean           - remove generated files in module directory only'
2129	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
2130	@echo  ''
2131
2132ifndef CONFIG_MODULES
2133modules modules_install: __external_modules_error
2134__external_modules_error:
2135	@echo >&2 '***'
2136	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
2137	@echo >&2 '*** You cannot build or install external modules.'
2138	@echo >&2 '***'
2139	@false
2140endif
2141
2142endif # KBUILD_EXTMOD
2143
2144# ---------------------------------------------------------------------------
2145# Modules
2146
2147PHONY += modules modules_install modules_sign modules_prepare
2148
2149modules_install:
2150	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
2151	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
2152
2153ifeq ($(CONFIG_MODULE_SIG),y)
2154# modules_sign is a subset of modules_install.
2155# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
2156modules_sign: modules_install
2157	@:
2158else
2159modules_sign:
2160	@echo >&2 '***'
2161	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
2162	@echo >&2 '***'
2163	@false
2164endif
2165
2166ifdef CONFIG_MODULES
2167
2168modules.order: $(build-dir)
2169	@:
2170
2171# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
2172# This is solely useful to speed up test compiles.
2173modules: modpost
2174ifneq ($(KBUILD_MODPOST_NOFINAL),1)
2175	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
2176endif
2177
2178PHONY += modules_check
2179modules_check: modules.order
2180	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
2181
2182else # CONFIG_MODULES
2183
2184modules:
2185	@:
2186
2187KBUILD_MODULES :=
2188
2189endif # CONFIG_MODULES
2190
2191PHONY += modpost
2192modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
2193	 $(if $(KBUILD_MODULES), modules_check)
2194	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2195
2196# Single targets
2197# ---------------------------------------------------------------------------
2198# To build individual files in subdirectories, you can do like this:
2199#
2200#   make foo/bar/baz.s
2201#
2202# The supported suffixes for single-target are listed in 'single-targets'
2203#
2204# To build only under specific subdirectories, you can do like this:
2205#
2206#   make foo/bar/baz/
2207
2208ifdef single-build
2209
2210# .ko is special because modpost is needed
2211single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
2212single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
2213		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
2214
2215$(single-ko): single_modules
2216	@:
2217$(single-no-ko): $(build-dir)
2218	@:
2219
2220# Remove modules.order when done because it is not the real one.
2221PHONY += single_modules
2222single_modules: $(single-no-ko) modules_prepare
2223	$(Q){ $(foreach m, $(single-ko), echo $(m:%.ko=%.o);) } > modules.order
2224	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2225ifneq ($(KBUILD_MODPOST_NOFINAL),1)
2226	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
2227endif
2228	$(Q)rm -f modules.order
2229
2230single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
2231
2232KBUILD_MODULES := y
2233
2234endif
2235
2236prepare: outputmakefile
2237
2238# Preset locale variables to speed up the build process. Limit locale
2239# tweaks to this spot to avoid wrong language settings when running
2240# make menuconfig etc.
2241# Error messages still appears in the original language
2242PHONY += $(build-dir)
2243$(build-dir): prepare
2244	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2245
2246clean-dirs := $(addprefix _clean_, $(clean-dirs))
2247PHONY += $(clean-dirs) clean
2248$(clean-dirs):
2249	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2250
2251clean: $(clean-dirs)
2252	$(call cmd,rmfiles)
2253	@find . $(RCS_FIND_IGNORE) \
2254		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2255		-o -name '*.ko.*' -o -name '*.o.thinlto.bc' \
2256		-o -name '*.dtb' -o -name '*.dtbo' \
2257		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2258		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
2259		-o -name '*.dwo' -o -name '*.lst' \
2260		-o -name '*.su' -o -name '*.mod' \
2261		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2262		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2263		-o -name '*.asn1.[ch]' \
2264		-o -name '*.symtypes' -o -name 'modules.order' \
2265		-o -name '*.c.[012]*.*' \
2266		-o -name '*.ll' \
2267		-o -name '*.gcno' \
2268		-o -name '*.long-type-*.txt' \
2269		-o -name '*.header-check' \
2270		\) -type f -print \
2271		-o -name '.tmp_*' -print \
2272		| xargs rm -rf
2273
2274# Generate tags for editors
2275# ---------------------------------------------------------------------------
2276quiet_cmd_tags = GEN     $@
2277      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2278
2279tags TAGS cscope gtags: FORCE
2280	$(call cmd,tags)
2281
2282# Generate rust-project.json (a file that describes the structure of non-Cargo
2283# Rust projects) for rust-analyzer (an implementation of the Language Server
2284# Protocol).
2285PHONY += rust-analyzer
2286rust-analyzer:
2287	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
2288ifdef KBUILD_EXTMOD
2289# FIXME: external modules must not descend into a sub-directory of the kernel
2290	$(Q)$(MAKE) $(build)=$(objtree)/rust src=$(srctree)/rust $@
2291else
2292	$(Q)$(MAKE) $(build)=rust $@
2293endif
2294
2295# Script to generate missing namespace dependencies
2296# ---------------------------------------------------------------------------
2297
2298PHONY += nsdeps
2299nsdeps: export KBUILD_NSDEPS=1
2300nsdeps: modules
2301	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2302
2303# Script to generate .spdx.json SBOM documents describing the build
2304# ---------------------------------------------------------------------------
2305
2306ifdef building_out_of_srctree
2307sbom_targets := sbom-source.spdx.json
2308endif
2309sbom_targets += sbom-build.spdx.json sbom-output.spdx.json
2310quiet_cmd_sbom = GEN     $(sbom_targets)
2311      cmd_sbom = printf "%s\n" "$(KBUILD_IMAGE)" >"$(tmp-target)"; \
2312                 $(if $(CONFIG_MODULES),sed 's/\.o$$/.ko/' $(objtree)/modules.order >> "$(tmp-target)";) \
2313                 $(PYTHON3) $(srctree)/scripts/sbom/sbom.py \
2314                     --src-tree $(abspath $(srctree)) \
2315                     --obj-tree $(abspath $(objtree)) \
2316                     --roots-file "$(tmp-target)" \
2317                     --output-directory $(abspath $(objtree)) \
2318                     --generate-spdx \
2319                     --package-license "GPL-2.0 WITH Linux-syscall-note" \
2320                     --package-version "$(KERNELVERSION)" \
2321                     --write-output-on-error;
2322PHONY += sbom
2323sbom: $(notdir $(KBUILD_IMAGE)) include/generated/autoconf.h $(if $(CONFIG_MODULES),modules modules.order)
2324	$(call cmd,sbom)
2325
2326# Clang Tooling
2327# ---------------------------------------------------------------------------
2328
2329quiet_cmd_gen_compile_commands = GEN     $@
2330      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2331
2332compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2333	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2334	$(if $(CONFIG_MODULES), modules.order) FORCE
2335	$(call if_changed,gen_compile_commands)
2336
2337targets += compile_commands.json
2338
2339PHONY += clang-tidy clang-analyzer
2340
2341ifdef CONFIG_CC_IS_CLANG
2342quiet_cmd_clang_tools = CHECK   $<
2343      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2344
2345clang-tidy clang-analyzer: compile_commands.json
2346	$(call cmd,clang_tools)
2347else
2348clang-tidy clang-analyzer:
2349	@echo "$@ requires CC=clang" >&2
2350	@false
2351endif
2352
2353# Scripts to check various things for consistency
2354# ---------------------------------------------------------------------------
2355
2356PHONY += includecheck versioncheck coccicheck kconfig-sym-check
2357
2358includecheck:
2359	find $(srctree)/* $(RCS_FIND_IGNORE) \
2360		-name '*.[hcS]' -type f -print | sort \
2361		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2362
2363versioncheck:
2364	find $(srctree)/* $(RCS_FIND_IGNORE) \
2365		-name '*.[hcS]' -type f -print | sort \
2366		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2367
2368coccicheck:
2369	$(Q)$(BASH) $(srctree)/scripts/$@
2370
2371kconfig-sym-check:
2372	$(Q)$(PERL) $(srctree)/scripts/kconfig/kconfig-sym-check.pl $(srctree) $(KCONFIG_SYM_CHECK_EXCLUDES)
2373
2374PHONY += checkstack kernelrelease kernelversion image_name
2375
2376# UML needs a little special treatment here.  It wants to use the host
2377# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2378# else wants $(ARCH), including people doing cross-builds, which means
2379# that $(SUBARCH) doesn't work here.
2380ifeq ($(ARCH), um)
2381CHECKSTACK_ARCH := $(SUBARCH)
2382else
2383CHECKSTACK_ARCH := $(ARCH)
2384endif
2385MINSTACKSIZE	?= 100
2386checkstack:
2387	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2388	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2389
2390kernelrelease:
2391	@$(filechk_kernel.release)
2392
2393kernelversion:
2394	@echo $(KERNELVERSION)
2395
2396image_name:
2397	@echo $(KBUILD_IMAGE)
2398
2399PHONY += run-command
2400run-command:
2401	$(Q)$(KBUILD_RUN_COMMAND)
2402
2403quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2404      cmd_rmfiles = rm -rf $(rm-files)
2405
2406# read saved command lines for existing targets
2407existing-targets := $(wildcard $(sort $(targets)))
2408
2409-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2410
2411endif # config-build
2412endif # mixed-build
2413endif # need-sub-make
2414
2415PHONY += FORCE
2416FORCE:
2417
2418# Declare the contents of the PHONY variable as phony.  We keep that
2419# information in a variable so we can use it in if_changed and friends.
2420.PHONY: $(PHONY)
2421