https://github.com/torvalds/linux
Revision a4412fdd49dc011bcc2c0d81ac4cab7457092650 authored by Steven Rostedt (Google) on 21 November 2022, 15:44:03 UTC, committed by Linus Torvalds on 01 December 2022, 21:14:21 UTC
The config to be able to inject error codes into any function annotated
with ALLOW_ERROR_INJECTION() is enabled when FUNCTION_ERROR_INJECTION is
enabled.  But unfortunately, this is always enabled on x86 when KPROBES
is enabled, and there's no way to turn it off.

As kprobes is useful for observability of the kernel, it is useful to
have it enabled in production environments.  But error injection should
be avoided.  Add a prompt to the config to allow it to be disabled even
when kprobes is enabled, and get rid of the "def_bool y".

This is a kernel debug feature (it's in Kconfig.debug), and should have
never been something enabled by default.

Cc: stable@vger.kernel.org
Fixes: 540adea3809f6 ("error-injection: Separate error-injection from kprobe")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 355479c
Raw File
Tip revision: a4412fdd49dc011bcc2c0d81ac4cab7457092650 authored by Steven Rostedt (Google) on 21 November 2022, 15:44:03 UTC
error-injection: Add prompt for function error injection
Tip revision: a4412fd
Makefile
# SPDX-License-Identifier: GPL-2.0
VERSION = 6
PATCHLEVEL = 1
SUBLEVEL = 0
EXTRAVERSION = -rc7
NAME = Hurr durr I'ma ninja sloth

# *DOCUMENTATION*
# To see a list of typical targets execute "make help"
# More info can be located in ./README
# Comments in this file are targeted only to the developer, do not
# expect to learn how to build the kernel reading this file.

$(if $(filter __%, $(MAKECMDGOALS)), \
	$(error targets prefixed with '__' are only for internal use))

# That's our default target when none is given on the command line
PHONY := __all
__all:

# We are using a recursive build, so we need to do a little thinking
# to get the ordering right.
#
# Most importantly: sub-Makefiles should only ever modify files in
# their own directory. If in some directory we have a dependency on
# a file in another dir (which doesn't happen often, but it's often
# unavoidable when linking the built-in.a targets which finally
# turn into vmlinux), we will call a sub make in that other dir, and
# after that we are sure that everything which is in that other dir
# is now up to date.
#
# The only cases where we need to modify files which have global
# effects are thus separated out and done before the recursive
# descending is started. They are now explicitly listed as the
# prepare rule.

ifneq ($(sub_make_done),1)

# Do not use make's built-in rules and variables
# (this increases performance and avoids hard-to-debug behaviour)
MAKEFLAGS += -rR

# Avoid funny character set dependencies
unexport LC_ALL
LC_COLLATE=C
LC_NUMERIC=C
export LC_COLLATE LC_NUMERIC

# Avoid interference with shell env settings
unexport GREP_OPTIONS

# Beautify output
# ---------------------------------------------------------------------------
#
# Normally, we echo the whole command before executing it. By making
# that echo $($(quiet)$(cmd)), we now have the possibility to set
# $(quiet) to choose other forms of output instead, e.g.
#
#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
#
# If $(quiet) is empty, the whole command will be printed.
# If it is set to "quiet_", only the short version will be printed.
# If it is set to "silent_", nothing will be printed at all, since
# the variable $(silent_cmd_cc_o_c) doesn't exist.
#
# A simple variant is to prefix commands with $(Q) - that's useful
# for commands that shall be hidden in non-verbose mode.
#
#	$(Q)ln $@ :<
#
# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
# If KBUILD_VERBOSE equals 1 then the above command is displayed.
# If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt.
#
# To put more focus on warnings, be less verbose as default
# Use 'make V=1' to see the full commands

ifeq ("$(origin V)", "command line")
  KBUILD_VERBOSE = $(V)
endif
ifndef KBUILD_VERBOSE
  KBUILD_VERBOSE = 0
endif

ifeq ($(KBUILD_VERBOSE),1)
  quiet =
  Q =
else
  quiet=quiet_
  Q = @
endif

# If the user is running make -s (silent mode), suppress echoing of
# commands

ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
  quiet=silent_
  KBUILD_VERBOSE = 0
endif

export quiet Q KBUILD_VERBOSE

# Call a source code checker (by default, "sparse") as part of the
# C compilation.
#
# Use 'make C=1' to enable checking of only re-compiled files.
# Use 'make C=2' to enable checking of *all* source files, regardless
# of whether they are re-compiled or not.
#
# See the file "Documentation/dev-tools/sparse.rst" for more details,
# including where to get the "sparse" utility.

ifeq ("$(origin C)", "command line")
  KBUILD_CHECKSRC = $(C)
endif
ifndef KBUILD_CHECKSRC
  KBUILD_CHECKSRC = 0
endif

export KBUILD_CHECKSRC

# Enable "clippy" (a linter) as part of the Rust compilation.
#
# Use 'make CLIPPY=1' to enable it.
ifeq ("$(origin CLIPPY)", "command line")
  KBUILD_CLIPPY := $(CLIPPY)
endif

export KBUILD_CLIPPY

# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
# directory of external module to build. Setting M= takes precedence.
ifeq ("$(origin M)", "command line")
  KBUILD_EXTMOD := $(M)
endif

$(if $(word 2, $(KBUILD_EXTMOD)), \
	$(error building multiple external modules is not supported))

$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
	$(error module directory path cannot contain '$x')))

# Remove trailing slashes
ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
endif

export KBUILD_EXTMOD

# Kbuild will save output files in the current working directory.
# This does not need to match to the root of the kernel source tree.
#
# For example, you can do this:
#
#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
#
# If you want to save output files in a different location, there are
# two syntaxes to specify it.
#
# 1) O=
# Use "make O=dir/to/store/output/files/"
#
# 2) Set KBUILD_OUTPUT
# Set the environment variable KBUILD_OUTPUT to point to the output directory.
# export KBUILD_OUTPUT=dir/to/store/output/files/; make
#
# The O= assignment takes precedence over the KBUILD_OUTPUT environment
# variable.

# Do we want to change the working directory?
ifeq ("$(origin O)", "command line")
  KBUILD_OUTPUT := $(O)
endif

ifneq ($(KBUILD_OUTPUT),)
# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
# expand a shell special character '~'. We use a somewhat tedious way here.
abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
$(if $(abs_objtree),, \
     $(error failed to create output directory "$(KBUILD_OUTPUT)"))

# $(realpath ...) resolves symlinks
abs_objtree := $(realpath $(abs_objtree))
else
abs_objtree := $(CURDIR)
endif # ifneq ($(KBUILD_OUTPUT),)

ifeq ($(abs_objtree),$(CURDIR))
# Suppress "Entering directory ..." unless we are changing the work directory.
MAKEFLAGS += --no-print-directory
else
need-sub-make := 1
endif

this-makefile := $(lastword $(MAKEFILE_LIST))
abs_srctree := $(realpath $(dir $(this-makefile)))

ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
$(error source directory cannot contain spaces or colons)
endif

ifneq ($(abs_srctree),$(abs_objtree))
# Look for make include files relative to root of kernel src
#
# --included-dir is added for backward compatibility, but you should not rely on
# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
MAKEFLAGS += --include-dir=$(abs_srctree)
endif

ifneq ($(filter 3.%,$(MAKE_VERSION)),)
# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
# We need to invoke sub-make to avoid implicit rules in the top Makefile.
need-sub-make := 1
# Cancel implicit rules for this Makefile.
$(this-makefile): ;
endif

export abs_srctree abs_objtree
export sub_make_done := 1

ifeq ($(need-sub-make),1)

PHONY += $(MAKECMDGOALS) __sub-make

$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
	@:

# Invoke a second make in the output directory, passing relevant variables
__sub-make:
	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)

endif # need-sub-make
endif # sub_make_done

# We process the rest of the Makefile if this is the final invocation of make
ifeq ($(need-sub-make),)

# Do not print "Entering directory ...",
# but we want to display it when entering to the output directory
# so that IDEs/editors are able to understand relative filenames.
MAKEFLAGS += --no-print-directory

ifeq ($(abs_srctree),$(abs_objtree))
        # building in the source tree
        srctree := .
	building_out_of_srctree :=
else
        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
                # building in a subdirectory of the source tree
                srctree := ..
        else
                srctree := $(abs_srctree)
        endif
	building_out_of_srctree := 1
endif

ifneq ($(KBUILD_ABS_SRCTREE),)
srctree := $(abs_srctree)
endif

objtree		:= .
VPATH		:= $(srctree)

export building_out_of_srctree srctree objtree VPATH

# To make sure we do not include .config for any of the *config targets
# catch them early, and hand them over to scripts/kconfig/Makefile
# It is allowed to specify more targets when calling make, including
# mixing *config targets and build targets.
# For example 'make oldconfig all'.
# Detect when mixed targets is specified, and make a second invocation
# of make so .config is not included in this case either (for *config).

version_h := include/generated/uapi/linux/version.h

clean-targets := %clean mrproper cleandocs
no-dot-config-targets := $(clean-targets) \
			 cscope gtags TAGS tags help% %docs check% coccicheck \
			 $(version_h) headers headers_% archheaders archscripts \
			 %asm-generic kernelversion %src-pkg dt_binding_check \
			 outputmakefile rustavailable rustfmt rustfmtcheck
# Installation targets should not require compiler. Unfortunately, vdso_install
# is an exception where build artifacts may be updated. This must be fixed.
no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
			headers_install modules_install kernelrelease image_name
no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
			  image_name
single-targets := %.a %.i %.rsi %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/

config-build	:=
mixed-build	:=
need-config	:= 1
need-compiler	:= 1
may-sync-config	:= 1
single-build	:=

ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
		need-config :=
	endif
endif

ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
		need-compiler :=
	endif
endif

ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
		may-sync-config :=
	endif
endif

ifneq ($(KBUILD_EXTMOD),)
	may-sync-config :=
endif

ifeq ($(KBUILD_EXTMOD),)
        ifneq ($(filter %config,$(MAKECMDGOALS)),)
		config-build := 1
                ifneq ($(words $(MAKECMDGOALS)),1)
			mixed-build := 1
                endif
        endif
endif

# We cannot build single targets and the others at the same time
ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
	single-build := 1
	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
		mixed-build := 1
	endif
endif

# For "make -j clean all", "make -j mrproper defconfig all", etc.
ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
		mixed-build := 1
        endif
endif

# install and modules_install need also be processed one by one
ifneq ($(filter install,$(MAKECMDGOALS)),)
        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
		mixed-build := 1
        endif
endif

ifdef mixed-build
# ===========================================================================
# We're called with mixed targets (*config and build targets).
# Handle them one by one.

PHONY += $(MAKECMDGOALS) __build_one_by_one

$(MAKECMDGOALS): __build_one_by_one
	@:

__build_one_by_one:
	$(Q)set -e; \
	for i in $(MAKECMDGOALS); do \
		$(MAKE) -f $(srctree)/Makefile $$i; \
	done

else # !mixed-build

include $(srctree)/scripts/Kbuild.include

# Read KERNELRELEASE from include/config/kernel.release (if it exists)
KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION

include $(srctree)/scripts/subarch.include

# Cross compiling and selecting different set of gcc/bin-utils
# ---------------------------------------------------------------------------
#
# When performing cross compilation for other architectures ARCH shall be set
# to the target architecture. (See arch/* for the possibilities).
# ARCH can be set during invocation of make:
# make ARCH=ia64
# Another way is to have ARCH set in the environment.
# The default ARCH is the host where make is executed.

# CROSS_COMPILE specify the prefix used for all executables used
# during compilation. Only gcc and related bin-utils executables
# are prefixed with $(CROSS_COMPILE).
# CROSS_COMPILE can be set on the command line
# make CROSS_COMPILE=ia64-linux-
# Alternatively CROSS_COMPILE can be set in the environment.
# Default value for CROSS_COMPILE is not to prefix executables
# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
ARCH		?= $(SUBARCH)

# Architecture as present in compile.h
UTS_MACHINE 	:= $(ARCH)
SRCARCH 	:= $(ARCH)

# Additional ARCH settings for x86
ifeq ($(ARCH),i386)
        SRCARCH := x86
endif
ifeq ($(ARCH),x86_64)
        SRCARCH := x86
endif

# Additional ARCH settings for sparc
ifeq ($(ARCH),sparc32)
       SRCARCH := sparc
endif
ifeq ($(ARCH),sparc64)
       SRCARCH := sparc
endif

# Additional ARCH settings for parisc
ifeq ($(ARCH),parisc64)
       SRCARCH := parisc
endif

export cross_compiling :=
ifneq ($(SRCARCH),$(SUBARCH))
cross_compiling := 1
endif

KCONFIG_CONFIG	?= .config
export KCONFIG_CONFIG

# SHELL used by kbuild
CONFIG_SHELL := sh

HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)

ifneq ($(LLVM),)
ifneq ($(filter %/,$(LLVM)),)
LLVM_PREFIX := $(LLVM)
else ifneq ($(filter -%,$(LLVM)),)
LLVM_SUFFIX := $(LLVM)
endif

HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
else
HOSTCC	= gcc
HOSTCXX	= g++
endif
HOSTRUSTC = rustc
HOSTPKG_CONFIG	= pkg-config

KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
			 -O2 -fomit-frame-pointer -std=gnu11 \
			 -Wdeclaration-after-statement
KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
KBUILD_USERLDFLAGS := $(USERLDFLAGS)

# These flags apply to all Rust code in the tree, including the kernel and
# host programs.
export rust_common_flags := --edition=2021 \
			    -Zbinary_dep_depinfo=y \
			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
			    -Dunreachable_pub -Dnon_ascii_idents \
			    -Wmissing_docs \
			    -Drustdoc::missing_crate_level_docs \
			    -Dclippy::correctness -Dclippy::style \
			    -Dclippy::suspicious -Dclippy::complexity \
			    -Dclippy::perf \
			    -Dclippy::let_unit_value -Dclippy::mut_mut \
			    -Dclippy::needless_bitwise_bool \
			    -Dclippy::needless_continue \
			    -Wclippy::dbg_macro

KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
			-Zallow-features= $(HOSTRUSTFLAGS)
KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)

# Make variables (CC, etc...)
CPP		= $(CC) -E
ifneq ($(LLVM),)
CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
else
CC		= $(CROSS_COMPILE)gcc
LD		= $(CROSS_COMPILE)ld
AR		= $(CROSS_COMPILE)ar
NM		= $(CROSS_COMPILE)nm
OBJCOPY		= $(CROSS_COMPILE)objcopy
OBJDUMP		= $(CROSS_COMPILE)objdump
READELF		= $(CROSS_COMPILE)readelf
STRIP		= $(CROSS_COMPILE)strip
endif
RUSTC		= rustc
RUSTDOC		= rustdoc
RUSTFMT		= rustfmt
CLIPPY_DRIVER	= clippy-driver
BINDGEN		= bindgen
CARGO		= cargo
PAHOLE		= pahole
RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
LEX		= flex
YACC		= bison
AWK		= awk
INSTALLKERNEL  := installkernel
DEPMOD		= depmod
PERL		= perl
PYTHON3		= python3
CHECK		= sparse
BASH		= bash
KGZIP		= gzip
KBZIP2		= bzip2
KLZOP		= lzop
LZMA		= lzma
LZ4		= lz4c
XZ		= xz
ZSTD		= zstd

PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)

CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
NOSTDINC_FLAGS :=
CFLAGS_MODULE   =
RUSTFLAGS_MODULE =
AFLAGS_MODULE   =
LDFLAGS_MODULE  =
CFLAGS_KERNEL	=
RUSTFLAGS_KERNEL =
AFLAGS_KERNEL	=
export LDFLAGS_vmlinux =

# Use USERINCLUDE when you must reference the UAPI directories only.
USERINCLUDE    := \
		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
		-I$(srctree)/include/uapi \
		-I$(objtree)/include/generated/uapi \
                -include $(srctree)/include/linux/compiler-version.h \
                -include $(srctree)/include/linux/kconfig.h

# Use LINUXINCLUDE when you must reference the include/ directory.
# Needed to be compatible with the O= option
LINUXINCLUDE    := \
		-I$(srctree)/arch/$(SRCARCH)/include \
		-I$(objtree)/arch/$(SRCARCH)/include/generated \
		$(if $(building_out_of_srctree),-I$(srctree)/include) \
		-I$(objtree)/include \
		$(USERINCLUDE)

KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
		   -Werror=implicit-function-declaration -Werror=implicit-int \
		   -Werror=return-type -Wno-format-security \
		   -std=gnu11
KBUILD_CPPFLAGS := -D__KERNEL__
KBUILD_RUSTFLAGS := $(rust_common_flags) \
		    --target=$(objtree)/rust/target.json \
		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
		    -Csymbol-mangling-version=v0 \
		    -Crelocation-model=static \
		    -Zfunction-sections=n \
		    -Dclippy::float_arithmetic

KBUILD_AFLAGS_KERNEL :=
KBUILD_CFLAGS_KERNEL :=
KBUILD_RUSTFLAGS_KERNEL :=
KBUILD_AFLAGS_MODULE  := -DMODULE
KBUILD_CFLAGS_MODULE  := -DMODULE
KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
KBUILD_LDFLAGS_MODULE :=
KBUILD_LDFLAGS :=
CLANG_FLAGS :=

ifeq ($(KBUILD_CLIPPY),1)
	RUSTC_OR_CLIPPY_QUIET := CLIPPY
	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
else
	RUSTC_OR_CLIPPY_QUIET := RUSTC
	RUSTC_OR_CLIPPY = $(RUSTC)
endif

ifdef RUST_LIB_SRC
	export RUST_LIB_SRC
endif

# Allows the usage of unstable features in stable compilers.
export RUSTC_BOOTSTRAP := 1

export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS

export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
export PAHOLE_FLAGS

# Files to ignore in find ... statements

export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
			  -prune -o
export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
			 --exclude CVS --exclude .pc --exclude .hg --exclude .git

# ===========================================================================
# Rules shared between *config targets and build targets

# Basic helpers built in scripts/basic/
PHONY += scripts_basic
scripts_basic:
	$(Q)$(MAKE) $(build)=scripts/basic

PHONY += outputmakefile
ifdef building_out_of_srctree
# Before starting out-of-tree build, make sure the source tree is clean.
# outputmakefile generates a Makefile in the output directory, if using a
# separate output directory. This allows convenient use of make in the
# output directory.
# At the same time when output Makefile generated, generate .gitignore to
# ignore whole output directory

quiet_cmd_makefile = GEN     Makefile
      cmd_makefile = { \
	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
	echo "include $(srctree)/Makefile"; \
	} > Makefile

outputmakefile:
	@if [ -f $(srctree)/.config -o \
		 -d $(srctree)/include/config -o \
		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
		echo >&2 "***"; \
		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
		echo >&2 "*** in $(abs_srctree)";\
		echo >&2 "***"; \
		false; \
	fi
	$(Q)ln -fsn $(srctree) source
	$(call cmd,makefile)
	$(Q)test -e .gitignore || \
	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
endif

# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
# and from include/config/auto.conf.cmd to detect the compiler upgrade.
CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))

ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
include $(srctree)/scripts/Makefile.clang
endif

# Include this also for config targets because some architectures need
# cc-cross-prefix to determine CROSS_COMPILE.
ifdef need-compiler
include $(srctree)/scripts/Makefile.compiler
endif

ifdef config-build
# ===========================================================================
# *config targets only - make sure prerequisites are updated, and descend
# in scripts/kconfig to make the *config target

# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
# KBUILD_DEFCONFIG may point out an alternative default configuration
# used for 'make defconfig'
include $(srctree)/arch/$(SRCARCH)/Makefile
export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT

config: outputmakefile scripts_basic FORCE
	$(Q)$(MAKE) $(build)=scripts/kconfig $@

%config: outputmakefile scripts_basic FORCE
	$(Q)$(MAKE) $(build)=scripts/kconfig $@

else #!config-build
# ===========================================================================
# Build targets only - this includes vmlinux, arch specific targets, clean
# targets and others. In general all targets except *config targets.

# If building an external module we do not care about the all: rule
# but instead __all depend on modules
PHONY += all
ifeq ($(KBUILD_EXTMOD),)
__all: all
else
__all: modules
endif

targets :=

# Decide whether to build built-in, modular, or both.
# Normally, just do built-in.

KBUILD_MODULES :=
KBUILD_BUILTIN := 1

# If we have only "make modules", don't compile built-in objects.
ifeq ($(MAKECMDGOALS),modules)
  KBUILD_BUILTIN :=
endif

# If we have "make <whatever> modules", compile modules
# in addition to whatever we do anyway.
# Just "make" or "make all" shall build modules as well

ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
  KBUILD_MODULES := 1
endif

ifeq ($(MAKECMDGOALS),)
  KBUILD_MODULES := 1
endif

export KBUILD_MODULES KBUILD_BUILTIN

ifdef need-config
include include/config/auto.conf
endif

ifeq ($(KBUILD_EXTMOD),)
# Objects we will link into vmlinux / subdirs we need to visit
core-y		:=
drivers-y	:=
libs-y		:= lib/
endif # KBUILD_EXTMOD

# The all: target is the default when no target is given on the
# command line.
# This allow a user to issue only 'make' to build a kernel including modules
# Defaults to vmlinux, but the arch makefile usually adds further targets
all: vmlinux

CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
ifdef CONFIG_CC_IS_GCC
CFLAGS_GCOV	+= -fno-tree-loop-im
endif
export CFLAGS_GCOV

# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
ifdef CONFIG_FUNCTION_TRACER
  CC_FLAGS_FTRACE := -pg
endif

include $(srctree)/arch/$(SRCARCH)/Makefile

ifdef need-config
ifdef may-sync-config
# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
# because some architectures define CROSS_COMPILE there.
include include/config/auto.conf.cmd

$(KCONFIG_CONFIG):
	@echo >&2 '***'
	@echo >&2 '*** Configuration file "$@" not found!'
	@echo >&2 '***'
	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
	@echo >&2 '*** "make menuconfig" or "make xconfig").'
	@echo >&2 '***'
	@/bin/false

# The actual configuration files used during the build are stored in
# include/generated/ and include/config/. Update them if .config is newer than
# include/config/auto.conf (which mirrors .config).
#
# This exploits the 'multi-target pattern rule' trick.
# The syncconfig should be executed only once to make all the targets.
# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
#
# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
# so you cannot notice that Kconfig is waiting for the user input.
%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
	$(Q)$(kecho) "  SYNC    $@"
	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
else # !may-sync-config
# External modules and some install targets need include/generated/autoconf.h
# and include/config/auto.conf but do not care if they are up-to-date.
# Use auto.conf to trigger the test
PHONY += include/config/auto.conf

include/config/auto.conf:
	@test -e include/generated/autoconf.h -a -e $@ || (		\
	echo >&2;							\
	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
	echo >&2 ;							\
	/bin/false)

endif # may-sync-config
endif # need-config

KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)

ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
KBUILD_CFLAGS += -O2
KBUILD_RUSTFLAGS += -Copt-level=2
else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS += -Os
KBUILD_RUSTFLAGS += -Copt-level=s
endif

# Always set `debug-assertions` and `overflow-checks` because their default
# depends on `opt-level` and `debug-assertions`, respectively.
KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)

# Tell gcc to never replace conditional load with a non-conditional one
ifdef CONFIG_CC_IS_GCC
# gcc-10 renamed --param=allow-store-data-races=0 to
# -fno-allow-store-data-races.
KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
endif

ifdef CONFIG_READABLE_ASM
# Disable optimizations that make assembler listings hard to read.
# reorder blocks reorders the control in the function
# ipa clone creates specialized cloned functions
# partial inlining inlines only parts of functions
KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
endif

ifneq ($(CONFIG_FRAME_WARN),0)
KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
endif

stackp-flags-y                                    := -fno-stack-protector
stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong

KBUILD_CFLAGS += $(stackp-flags-y)

KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds

KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)

ifdef CONFIG_CC_IS_CLANG
KBUILD_CPPFLAGS += -Qunused-arguments
# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
KBUILD_CFLAGS += -Wno-gnu
else

# gcc inanely warns about local variables called 'main'
KBUILD_CFLAGS += -Wno-main
endif

# These warnings generated too much noise in a regular build.
# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)

# These result in bogus false positives
KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)

ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
else
# Some targets (ARM with Thumb2, for example), can't be built with frame
# pointers.  For those, we don't have FUNCTION_TRACER automatically
# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
# incompatible with -fomit-frame-pointer with current GCC, so we don't use
# -fomit-frame-pointer with FUNCTION_TRACER.
# In the Rust target specification, "frame-pointer" is set explicitly
# to "may-omit".
ifndef CONFIG_FUNCTION_TRACER
KBUILD_CFLAGS	+= -fomit-frame-pointer
endif
endif

# Initialize all stack variables with a 0xAA pattern.
ifdef CONFIG_INIT_STACK_ALL_PATTERN
KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
endif

# Initialize all stack variables with a zero value.
ifdef CONFIG_INIT_STACK_ALL_ZERO
KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
# https://github.com/llvm/llvm-project/issues/44842
KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
endif
endif

# While VLAs have been removed, GCC produces unreachable stack probes
# for the randomize_kstack_offset feature. Disable it for all compilers.
KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)

# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
ifdef CONFIG_ZERO_CALL_USED_REGS
KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
endif

ifdef CONFIG_FUNCTION_TRACER
ifdef CONFIG_FTRACE_MCOUNT_USE_CC
  CC_FLAGS_FTRACE	+= -mrecord-mcount
  ifdef CONFIG_HAVE_NOP_MCOUNT
    ifeq ($(call cc-option-yn, -mnop-mcount),y)
      CC_FLAGS_FTRACE	+= -mnop-mcount
      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
    endif
  endif
endif
ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
endif
ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
  ifdef CONFIG_HAVE_C_RECORDMCOUNT
    BUILD_C_RECORDMCOUNT := y
    export BUILD_C_RECORDMCOUNT
  endif
endif
ifdef CONFIG_HAVE_FENTRY
  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
  ifeq ($(call cc-option-yn, -mfentry),y)
    CC_FLAGS_FTRACE	+= -mfentry
    CC_FLAGS_USING	+= -DCC_USING_FENTRY
  endif
endif
export CC_FLAGS_FTRACE
KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
endif

# We trigger additional mismatches with less inlining
ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += -fno-inline-functions-called-once
endif

# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
LDFLAGS_vmlinux += --gc-sections
endif

ifdef CONFIG_SHADOW_CALL_STACK
CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
export CC_FLAGS_SCS
endif

ifdef CONFIG_LTO_CLANG
ifdef CONFIG_LTO_CLANG_THIN
CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
else
CC_FLAGS_LTO	:= -flto
endif
CC_FLAGS_LTO	+= -fvisibility=hidden

# Limit inlining across translation units to reduce binary size
KBUILD_LDFLAGS += -mllvm -import-instr-limit=5

# Check for frame size exceeding threshold during prolog/epilog insertion
# when using lld < 13.0.0.
ifneq ($(CONFIG_FRAME_WARN),0)
ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
endif
endif
endif

ifdef CONFIG_LTO
KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
KBUILD_AFLAGS	+= -fno-lto
export CC_FLAGS_LTO
endif

ifdef CONFIG_CFI_CLANG
CC_FLAGS_CFI	:= -fsanitize=kcfi
KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
export CC_FLAGS_CFI
endif

ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
KBUILD_CFLAGS += -falign-functions=64
endif

# arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc

# warn about C99 declaration after statement
KBUILD_CFLAGS += -Wdeclaration-after-statement

# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
KBUILD_CFLAGS += -Wvla

# disable pointer signed / unsigned warnings in gcc 4.0
KBUILD_CFLAGS += -Wno-pointer-sign

# In order to make sure new function cast mismatches are not introduced
# in the kernel (to avoid tripping CFI checking), the kernel should be
# globally built with -Wcast-function-type.
KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)

# disable stringop warnings in gcc 8+
KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)

# We'll want to enable this eventually, but it's not going away for 5.7 at least
KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)

# Another good warning that we'll want to enable eventually
KBUILD_CFLAGS += $(call cc-disable-warning, restrict)

# Enabled with W=2, disabled by default as noisy
ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS += -Wno-maybe-uninitialized
endif

# The allocators already balk at large sizes, so silence the compiler
# warnings for bounds checks involving those possible values. While
# -Wno-alloc-size-larger-than would normally be used here, earlier versions
# of gcc (<9.1) weirdly don't handle the option correctly when _other_
# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
# doesn't work (as it is documented to), silently resolving to "0" prior to
# version 9.1 (and producing an error more recently). Numeric values larger
# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
# choice, we must perform a versioned check to disable this warning.
# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)

# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS	+= -fno-strict-overflow

# Make sure -fstack-check isn't enabled (like gentoo apparently did)
KBUILD_CFLAGS  += -fno-stack-check

# conserve stack if available
ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS   += -fconserve-stack
endif

# Prohibit date/time macros, which would make the build non-deterministic
KBUILD_CFLAGS   += -Werror=date-time

# enforce correct pointer usage
KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)

# Require designated initializers for all marked structures
KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)

# change __FILE__ to the relative path from the srctree
KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)

# include additional Makefiles when needed
include-y			:= scripts/Makefile.extrawarn
include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins

include $(addprefix $(srctree)/, $(include-y))

# scripts/Makefile.gcc-plugins is intentionally included last.
# Do not add $(call cc-option,...) below this line. When you build the kernel
# from the clean source tree, the GCC plugins do not exist at this point.

# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
KBUILD_CPPFLAGS += $(KCPPFLAGS)
KBUILD_AFLAGS   += $(KAFLAGS)
KBUILD_CFLAGS   += $(KCFLAGS)
KBUILD_RUSTFLAGS += $(KRUSTFLAGS)

KBUILD_LDFLAGS_MODULE += --build-id=sha1
LDFLAGS_vmlinux += --build-id=sha1

KBUILD_LDFLAGS	+= -z noexecstack
ifeq ($(CONFIG_LD_IS_BFD),y)
KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
endif

ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
LDFLAGS_vmlinux	+= -X
endif

ifeq ($(CONFIG_RELR),y)
LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
endif

# We never want expected sections to be placed heuristically by the
# linker. All sections should be explicitly named in the linker script.
ifdef CONFIG_LD_ORPHAN_WARN
LDFLAGS_vmlinux += --orphan-handling=warn
endif

# Align the bit size of userspace programs with the kernel
KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))

# make the checker run with the right architecture
CHECKFLAGS += --arch=$(ARCH)

# insure the checker run with the right endianness
CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)

# the checker needs the correct machine size
CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)

# Default kernel image to build when no specific target is given.
# KBUILD_IMAGE may be overruled on the command line or
# set in the environment
# Also any assignments in arch/$(ARCH)/Makefile take precedence over
# this default value
export KBUILD_IMAGE ?= vmlinux

#
# INSTALL_PATH specifies where to place the updated kernel and system map
# images. Default is /boot, but you can set it to other values
export	INSTALL_PATH ?= /boot

#
# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
# an argument if needed. Otherwise it defaults to the kernel install path
#
export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)

#
# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
# relocations required by build roots.  This is not defined in the
# makefile but the argument can be passed to make if needed.
#

MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
export MODLIB

PHONY += prepare0

export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
export MODORDER := $(extmod_prefix)modules.order
export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps

ifeq ($(KBUILD_EXTMOD),)

build-dir	:= .
clean-dirs	:= $(sort . Documentation \
		     $(patsubst %/,%,$(filter %/, $(core-) \
			$(drivers-) $(libs-))))

export ARCH_CORE	:= $(core-y)
export ARCH_LIB		:= $(filter %/, $(libs-y))
export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
# Externally visible symbols (used by link-vmlinux.sh)

KBUILD_VMLINUX_OBJS := ./built-in.a
ifdef CONFIG_MODULES
KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
else
KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
endif

export KBUILD_VMLINUX_LIBS
export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds

# Recurse until adjust_autoksyms.sh is satisfied
PHONY += autoksyms_recursive
ifdef CONFIG_TRIM_UNUSED_KSYMS
# For the kernel to actually contain only the needed exported symbols,
# we have to build modules as well to determine what those symbols are.
# (this can be evaluated only once include/config/auto.conf has been included)
KBUILD_MODULES := 1

autoksyms_recursive: $(build-dir) modules.order
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
endif

autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)

quiet_cmd_autoksyms_h = GEN     $@
      cmd_autoksyms_h = mkdir -p $(dir $@); \
			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@

$(autoksyms_h):
	$(call cmd,autoksyms_h)

# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
quiet_cmd_ar_vmlinux.a = AR      $@
      cmd_ar_vmlinux.a = \
	rm -f $@; \
	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)

targets += vmlinux.a
vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
	$(call if_changed,ar_vmlinux.a)

PHONY += vmlinux_o
vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o

vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
	@:

PHONY += vmlinux
vmlinux: vmlinux.o $(KBUILD_LDS) modpost
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux

# The actual objects are generated when descending,
# make sure no implicit rule kicks in
$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;

filechk_kernel.release = \
	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"

# Store (new) KERNELRELEASE string in include/config/kernel.release
include/config/kernel.release: FORCE
	$(call filechk,kernel.release)

# Additional helpers built in scripts/
# Carefully list dependencies so we do not try to build scripts twice
# in parallel
PHONY += scripts
scripts: scripts_basic scripts_dtc
	$(Q)$(MAKE) $(build)=$(@)

# Things we need to do before we recursively start building the kernel
# or the modules are listed in "prepare".
# A multi level approach is used. prepareN is processed before prepareN-1.
# archprepare is used in arch Makefiles and when processed asm symlink,
# version.h and scripts_basic is processed / created.

PHONY += prepare archprepare

archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
	include/generated/compile.h include/generated/autoconf.h remove-stale-files

prepare0: archprepare
	$(Q)$(MAKE) $(build)=scripts/mod
	$(Q)$(MAKE) $(build)=. prepare

# All the preparing..
prepare: prepare0
ifdef CONFIG_RUST
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
	$(Q)$(MAKE) $(build)=rust
endif

PHONY += remove-stale-files
remove-stale-files:
	$(Q)$(srctree)/scripts/remove-stale-files

# Support for using generic headers in asm-generic
asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj

PHONY += asm-generic uapi-asm-generic
asm-generic: uapi-asm-generic
	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
	generic=include/asm-generic
uapi-asm-generic:
	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
	generic=include/uapi/asm-generic

# Generate some files
# ---------------------------------------------------------------------------

# KERNELRELEASE can change from a few different places, meaning version.h
# needs to be updated, so this check is forced on all builds

uts_len := 64
define filechk_utsrelease.h
	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
	  exit 1;                                                         \
	fi;                                                               \
	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
endef

define filechk_version.h
	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
		echo \#define LINUX_VERSION_CODE $(shell                 \
		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
	else                                                             \
		echo \#define LINUX_VERSION_CODE $(shell                 \
		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
	fi;                                                              \
	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
	((c) > 255 ? 255 : (c)))';                                       \
	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
endef

$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
$(version_h): FORCE
	$(call filechk,version.h)

include/generated/utsrelease.h: include/config/kernel.release FORCE
	$(call filechk,utsrelease.h)

filechk_compile.h = $(srctree)/scripts/mkcompile_h \
	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"

include/generated/compile.h: FORCE
	$(call filechk,compile.h)

PHONY += headerdep
headerdep:
	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
	$(srctree)/scripts/headerdep.pl -I$(srctree)/include

# ---------------------------------------------------------------------------
# Kernel headers

#Default location for installed headers
export INSTALL_HDR_PATH = $(objtree)/usr

quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
      cmd_headers_install = \
	mkdir -p $(INSTALL_HDR_PATH); \
	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
	usr/include $(INSTALL_HDR_PATH)

PHONY += headers_install
headers_install: headers
	$(call cmd,headers_install)

PHONY += archheaders archscripts

hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj

PHONY += headers
headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
	$(Q)$(MAKE) $(hdr-inst)=include/uapi
	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi

ifdef CONFIG_HEADERS_INSTALL
prepare: headers
endif

PHONY += scripts_unifdef
scripts_unifdef: scripts_basic
	$(Q)$(MAKE) $(build)=scripts scripts/unifdef

# ---------------------------------------------------------------------------
# Install

# Many distributions have the custom install script, /sbin/installkernel.
# If DKMS is installed, 'make install' will eventually recurse back
# to this Makefile to build and install external modules.
# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.

quiet_cmd_install = INSTALL $(INSTALL_PATH)
      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh

# ---------------------------------------------------------------------------
# Tools

ifdef CONFIG_OBJTOOL
prepare: tools/objtool
endif

ifdef CONFIG_BPF
ifdef CONFIG_DEBUG_INFO_BTF
prepare: tools/bpf/resolve_btfids
endif
endif

PHONY += resolve_btfids_clean

resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids

# tools/bpf/resolve_btfids directory might not exist
# in output directory, skip its clean in that case
resolve_btfids_clean:
ifneq ($(wildcard $(resolve_btfids_O)),)
	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
endif

# Clear a bunch of variables before executing the submake
ifeq ($(quiet),silent_)
tools_silent=s
endif

tools/: FORCE
	$(Q)mkdir -p $(objtree)/tools
	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/

tools/%: FORCE
	$(Q)mkdir -p $(objtree)/tools
	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*

# ---------------------------------------------------------------------------
# Kernel selftest

PHONY += kselftest
kselftest: headers
	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests

kselftest-%: headers FORCE
	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*

PHONY += kselftest-merge
kselftest-merge:
	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
	$(Q)find $(srctree)/tools/testing/selftests -name config | \
		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig

# ---------------------------------------------------------------------------
# Devicetree files

ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
dtstree := arch/$(SRCARCH)/boot/dts
endif

ifneq ($(dtstree),)

%.dtb: dtbs_prepare
	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@

%.dtbo: dtbs_prepare
	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@

PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
dtbs: dtbs_prepare
	$(Q)$(MAKE) $(build)=$(dtstree)

# include/config/kernel.release is actually needed when installing DTBs because
# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
# dtbs_install depend on it as dtbs_install may run as root.
dtbs_prepare: include/config/kernel.release scripts_dtc

ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
export CHECK_DTBS=y
dtbs: dt_binding_check
endif

dtbs_check: dtbs

dtbs_install:
	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)

ifdef CONFIG_OF_EARLY_FLATTREE
all: dtbs
endif

endif

PHONY += scripts_dtc
scripts_dtc: scripts_basic
	$(Q)$(MAKE) $(build)=scripts/dtc

ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
export CHECK_DT_BINDING=y
endif

PHONY += dt_binding_check
dt_binding_check: scripts_dtc
	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings

PHONY += dt_compatible_check
dt_compatible_check: dt_binding_check
	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@

# ---------------------------------------------------------------------------
# Modules

ifdef CONFIG_MODULES

# By default, build modules as well

all: modules

# When we're building modules with modversions, we need to consider
# the built-in objects during the descend as well, in order to
# make sure the checksums are up to date before we record them.
ifdef CONFIG_MODVERSIONS
  KBUILD_BUILTIN := 1
endif

# Build modules
#

# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFOBTF_MODULES
# is an exception.
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
modules: vmlinux
endif

modules: modules_prepare

# Target to prepare building external modules
modules_prepare: prepare
	$(Q)$(MAKE) $(build)=scripts scripts/module.lds

export modules_sign_only :=

ifeq ($(CONFIG_MODULE_SIG),y)
PHONY += modules_sign
modules_sign: modules_install
	@:

# modules_sign is a subset of modules_install.
# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
modules_sign_only := y
endif
endif

modinst_pre :=
ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
modinst_pre := __modinst_pre
endif

modules_install: $(modinst_pre)
PHONY += __modinst_pre
__modinst_pre:
	@rm -rf $(MODLIB)/kernel
	@rm -f $(MODLIB)/source
	@mkdir -p $(MODLIB)/kernel
	@ln -s $(abspath $(srctree)) $(MODLIB)/source
	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
		rm -f $(MODLIB)/build ; \
		ln -s $(CURDIR) $(MODLIB)/build ; \
	fi
	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
	@cp -f modules.builtin $(MODLIB)/
	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/

endif # CONFIG_MODULES

###
# Cleaning is done on three levels.
# make clean     Delete most generated files
#                Leave enough to build external modules
# make mrproper  Delete the current configuration, and all generated files
# make distclean Remove editor backup files, patch leftover files and the like

# Directories & files removed with 'make clean'
CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
	       modules.builtin modules.builtin.modinfo modules.nsdeps \
	       compile_commands.json .thinlto-cache rust/test rust/doc \
	       .vmlinux.objs .vmlinux.export.c

# Directories & files removed with 'make mrproper'
MRPROPER_FILES += include/config include/generated          \
		  arch/$(SRCARCH)/include/generated .objdiff \
		  debian snap tar-install \
		  .config .config.old .version \
		  Module.symvers \
		  certs/signing_key.pem \
		  certs/x509.genkey \
		  vmlinux-gdb.py \
		  *.spec \
		  rust/target.json rust/libmacros.so

# clean - Delete most, but leave enough to build external modules
#
clean: rm-files := $(CLEAN_FILES)

PHONY += archclean vmlinuxclean

vmlinuxclean:
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)

clean: archclean vmlinuxclean resolve_btfids_clean

# mrproper - Delete all generated files, including .config
#
mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
mrproper-dirs      := $(addprefix _mrproper_,scripts)

PHONY += $(mrproper-dirs) mrproper
$(mrproper-dirs):
	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)

mrproper: clean $(mrproper-dirs)
	$(call cmd,rmfiles)
	@find . $(RCS_FIND_IGNORE) \
		\( -name '*.rmeta' \) \
		-type f -print | xargs rm -f

# distclean
#
PHONY += distclean

distclean: mrproper
	@find . $(RCS_FIND_IGNORE) \
		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
		-type f -print | xargs rm -f


# Packaging of the kernel to various formats
# ---------------------------------------------------------------------------

%src-pkg: FORCE
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
%pkg: include/config/kernel.release FORCE
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@

# Brief documentation of the typical targets used
# ---------------------------------------------------------------------------

boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
boards := $(sort $(notdir $(boards)))
board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
board-dirs := $(sort $(notdir $(board-dirs:/=)))

PHONY += help
help:
	@echo  'Cleaning targets:'
	@echo  '  clean		  - Remove most generated files but keep the config and'
	@echo  '                    enough build support to build external modules'
	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
	@echo  ''
	@echo  'Configuration targets:'
	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
	@echo  ''
	@echo  'Other generic targets:'
	@echo  '  all		  - Build all targets marked with [*]'
	@echo  '* vmlinux	  - Build the bare kernel'
	@echo  '* modules	  - Build all modules'
	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
	@echo  '  dir/            - Build all files in dir and below'
	@echo  '  dir/file.[ois]  - Build specified target only'
	@echo  '  dir/file.ll     - Build the LLVM assembly file'
	@echo  '                    (requires compiler support for LLVM assembly generation)'
	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
	@echo  '                    (requires a recent binutils and recent build (System.map))'
	@echo  '  dir/file.ko     - Build module including final link'
	@echo  '  modules_prepare - Set up for building external modules'
	@echo  '  tags/TAGS	  - Generate tags file for editors'
	@echo  '  cscope	  - Generate cscope index'
	@echo  '  gtags           - Generate GNU GLOBAL index'
	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
	@echo  '  image_name	  - Output the image name (use with make -s)'
	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
	 echo  ''
	@echo  'Static analysers:'
	@echo  '  checkstack      - Generate a list of stack hogs'
	@echo  '  versioncheck    - Sanity check on version.h usage'
	@echo  '  includecheck    - Check for duplicate included header files'
	@echo  '  export_report   - List the usages of all exported symbols'
	@echo  '  headerdep       - Detect inclusion cycles in headers'
	@echo  '  coccicheck      - Check with Coccinelle'
	@echo  '  clang-analyzer  - Check with clang static analyzer'
	@echo  '  clang-tidy      - Check with clang-tidy'
	@echo  ''
	@echo  'Tools:'
	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
	@echo  ''
	@echo  'Kernel selftest:'
	@echo  '  kselftest         - Build and run kernel selftest'
	@echo  '                      Build, install, and boot kernel before'
	@echo  '                      running kselftest on it'
	@echo  '                      Run as root for full coverage'
	@echo  '  kselftest-all     - Build kernel selftest'
	@echo  '  kselftest-install - Build and install kernel selftest'
	@echo  '  kselftest-clean   - Remove all generated kselftest files'
	@echo  '  kselftest-merge   - Merge all the config dependencies of'
	@echo  '		      kselftest to existing .config.'
	@echo  ''
	@echo  'Rust targets:'
	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
	@echo  '		    available and, if not, explains why.'
	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
	@echo  '		    is formatted, printing a diff otherwise.'
	@echo  '  rustdoc	  - Generate Rust documentation'
	@echo  '		    (requires kernel .config)'
	@echo  '  rusttest        - Runs the Rust tests'
	@echo  '                    (requires kernel .config; downloads external repos)'
	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
	@echo  '		    (requires kernel .config)'
	@echo  '  dir/file.[os]   - Build specified target only'
	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
	@echo  '                    The output is not intended to be compilable.'
	@echo  '  dir/file.ll     - Build the LLVM assembly file'
	@echo  ''
	@$(if $(dtstree), \
		echo 'Devicetree:'; \
		echo '* dtbs             - Build device tree blobs for enabled boards'; \
		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
		echo '  dt_binding_check - Validate device tree binding documents'; \
		echo '  dtbs_check       - Validate device tree source files';\
		echo '')

	@echo 'Userspace tools targets:'
	@echo '  use "make tools/help"'
	@echo '  or  "cd tools; make help"'
	@echo  ''
	@echo  'Kernel packaging:'
	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
	@echo  ''
	@echo  'Documentation targets:'
	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
	@echo  ''
	@echo  'Architecture specific targets ($(SRCARCH)):'
	@$(or $(archhelp),\
		echo '  No architecture specific help defined for $(SRCARCH)')
	@echo  ''
	@$(if $(boards), \
		$(foreach b, $(boards), \
		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
		echo '')
	@$(if $(board-dirs), \
		$(foreach b, $(board-dirs), \
		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
		printf "  %-16s - Show all of the above\\n" help-boards; \
		echo '')

	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
	@echo  '                       (sparse by default)'
	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
	@echo  '		1: warnings which may be relevant and do not occur too often'
	@echo  '		2: warnings which occur quite often but may still be relevant'
	@echo  '		3: more obscure warnings, can most likely be ignored'
	@echo  '		e: warnings are being treated as errors'
	@echo  '		Multiple levels can be combined with W=12 or W=123'
	@echo  ''
	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
	@echo  'For further info see the ./README file'


help-board-dirs := $(addprefix help-,$(board-dirs))

help-boards: $(help-board-dirs)

boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))

$(help-board-dirs): help-%:
	@echo  'Architecture specific targets ($(SRCARCH) $*):'
	@$(if $(boards-per-dir), \
		$(foreach b, $(boards-per-dir), \
		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
		echo '')


# Documentation targets
# ---------------------------------------------------------------------------
DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
	       linkcheckdocs dochelp refcheckdocs
PHONY += $(DOC_TARGETS)
$(DOC_TARGETS):
	$(Q)$(MAKE) $(build)=Documentation $@


# Rust targets
# ---------------------------------------------------------------------------

# "Is Rust available?" target
PHONY += rustavailable
rustavailable:
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"

# Documentation target
#
# Using the singular to avoid running afoul of `no-dot-config-targets`.
PHONY += rustdoc
rustdoc: prepare
	$(Q)$(MAKE) $(build)=rust $@

# Testing target
PHONY += rusttest
rusttest: prepare
	$(Q)$(MAKE) $(build)=rust $@

# Formatting targets
PHONY += rustfmt rustfmtcheck

# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
#
# We match using absolute paths since `find` does not resolve them
# when matching, which is a problem when e.g. `srctree` is `..`.
# We `grep` afterwards in order to remove the directory entry itself.
rustfmt:
	$(Q)find $(abs_srctree) -type f -name '*.rs' \
		-o -path $(abs_srctree)/rust/alloc -prune \
		-o -path $(abs_objtree)/rust/test -prune \
		| grep -Fv $(abs_srctree)/rust/alloc \
		| grep -Fv $(abs_objtree)/rust/test \
		| grep -Fv generated \
		| xargs $(RUSTFMT) $(rustfmt_flags)

rustfmtcheck: rustfmt_flags = --check
rustfmtcheck: rustfmt

# IDE support targets
PHONY += rust-analyzer
rust-analyzer:
	$(Q)$(MAKE) $(build)=rust $@

# Misc
# ---------------------------------------------------------------------------

PHONY += scripts_gdb
scripts_gdb: prepare0
	$(Q)$(MAKE) $(build)=scripts/gdb
	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)

ifdef CONFIG_GDB_SCRIPTS
all: scripts_gdb
endif

else # KBUILD_EXTMOD

###
# External module support.
# When building external modules the kernel used as basis is considered
# read-only, and no consistency checks are made and the make
# system is not used on the basis kernel. If updates are required
# in the basis kernel ordinary make commands (without M=...) must be used.

# We are always building only modules.
KBUILD_BUILTIN :=
KBUILD_MODULES := 1

build-dir := $(KBUILD_EXTMOD)

compile_commands.json: $(extmod_prefix)compile_commands.json
PHONY += compile_commands.json

clean-dirs := $(KBUILD_EXTMOD)
clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache

PHONY += prepare
# now expand this into a simple variable to reduce the cost of shell evaluations
prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
prepare:
	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
	fi

PHONY += help
help:
	@echo  '  Building external modules.'
	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
	@echo  ''
	@echo  '  modules         - default target, build the module(s)'
	@echo  '  modules_install - install the module'
	@echo  '  clean           - remove generated files in module directory only'
	@echo  ''

endif # KBUILD_EXTMOD

# ---------------------------------------------------------------------------
# Modules

PHONY += modules modules_install modules_prepare

ifdef CONFIG_MODULES

$(MODORDER): $(build-dir)
	@:

# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
# This is solely useful to speed up test compiles.
modules: modpost
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif

PHONY += modules_check
modules_check: $(MODORDER)
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<

quiet_cmd_depmod = DEPMOD  $(MODLIB)
      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
                   $(KERNELRELEASE)

modules_install:
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
	$(call cmd,depmod)

else # CONFIG_MODULES

# Modules not configured
# ---------------------------------------------------------------------------

modules modules_install:
	@echo >&2 '***'
	@echo >&2 '*** The present kernel configuration has modules disabled.'
	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
	@echo >&2 '*** to enable CONFIG_MODULES.'
	@echo >&2 '***'
	@exit 1

KBUILD_MODULES :=

endif # CONFIG_MODULES

PHONY += modpost
modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
	 $(if $(KBUILD_MODULES), modules_check)
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost

# Single targets
# ---------------------------------------------------------------------------
# To build individual files in subdirectories, you can do like this:
#
#   make foo/bar/baz.s
#
# The supported suffixes for single-target are listed in 'single-targets'
#
# To build only under specific subdirectories, you can do like this:
#
#   make foo/bar/baz/

ifdef single-build

# .ko is special because modpost is needed
single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))

$(single-ko): single_modules
	@:
$(single-no-ko): $(build-dir)
	@:

# Remove MODORDER when done because it is not the real one.
PHONY += single_modules
single_modules: $(single-no-ko) modules_prepare
	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif
	$(Q)rm -f $(MODORDER)

single-goals := $(addprefix $(build-dir)/, $(single-no-ko))

KBUILD_MODULES := 1

endif

# Preset locale variables to speed up the build process. Limit locale
# tweaks to this spot to avoid wrong language settings when running
# make menuconfig etc.
# Error messages still appears in the original language
PHONY += $(build-dir)
$(build-dir): prepare
	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)

clean-dirs := $(addprefix _clean_, $(clean-dirs))
PHONY += $(clean-dirs) clean
$(clean-dirs):
	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)

clean: $(clean-dirs)
	$(call cmd,rmfiles)
	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
		-o -name '*.ko.*' \
		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
		-o -name '*.dwo' -o -name '*.lst' \
		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
		-o -name '*.asn1.[ch]' \
		-o -name '*.symtypes' -o -name 'modules.order' \
		-o -name '.tmp_*' \
		-o -name '*.c.[012]*.*' \
		-o -name '*.ll' \
		-o -name '*.gcno' \
		-o -name '*.*.symversions' \) -type f -print | xargs rm -f

# Generate tags for editors
# ---------------------------------------------------------------------------
quiet_cmd_tags = GEN     $@
      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@

tags TAGS cscope gtags: FORCE
	$(call cmd,tags)

# Script to generate missing namespace dependencies
# ---------------------------------------------------------------------------

PHONY += nsdeps
nsdeps: export KBUILD_NSDEPS=1
nsdeps: modules
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps

# Clang Tooling
# ---------------------------------------------------------------------------

quiet_cmd_gen_compile_commands = GEN     $@
      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))

$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
	$(call if_changed,gen_compile_commands)

targets += $(extmod_prefix)compile_commands.json

PHONY += clang-tidy clang-analyzer

ifdef CONFIG_CC_IS_CLANG
quiet_cmd_clang_tools = CHECK   $<
      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<

clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
	$(call cmd,clang_tools)
else
clang-tidy clang-analyzer:
	@echo "$@ requires CC=clang" >&2
	@false
endif

# Scripts to check various things for consistency
# ---------------------------------------------------------------------------

PHONY += includecheck versioncheck coccicheck export_report

includecheck:
	find $(srctree)/* $(RCS_FIND_IGNORE) \
		-name '*.[hcS]' -type f -print | sort \
		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl

versioncheck:
	find $(srctree)/* $(RCS_FIND_IGNORE) \
		-name '*.[hcS]' -type f -print | sort \
		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl

coccicheck:
	$(Q)$(BASH) $(srctree)/scripts/$@

export_report:
	$(PERL) $(srctree)/scripts/export_report.pl

PHONY += checkstack kernelrelease kernelversion image_name

# UML needs a little special treatment here.  It wants to use the host
# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
# else wants $(ARCH), including people doing cross-builds, which means
# that $(SUBARCH) doesn't work here.
ifeq ($(ARCH), um)
CHECKSTACK_ARCH := $(SUBARCH)
else
CHECKSTACK_ARCH := $(ARCH)
endif
checkstack:
	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)

kernelrelease:
	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"

kernelversion:
	@echo $(KERNELVERSION)

image_name:
	@echo $(KBUILD_IMAGE)

quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
      cmd_rmfiles = rm -rf $(rm-files)

# read saved command lines for existing targets
existing-targets := $(wildcard $(sort $(targets)))

-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)

endif # config-build
endif # mixed-build
endif # need-sub-make

PHONY += FORCE
FORCE:

# Declare the contents of the PHONY variable as phony.  We keep that
# information in a variable so we can use it in if_changed and friends.
.PHONY: $(PHONY)
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