# SPDX-License-Identifier: GPL-2.0

# Backward compatibility

asflags-y += $(EXTRA_AFLAGS)

ccflags-y += $(EXTRA_CFLAGS)

cppflags-y += $(EXTRA_CPPFLAGS)

ldflags-y += $(EXTRA_LDFLAGS)

# flags that take effect in current and sub directories

KBUILD_AFLAGS += $(subdir-asflags-y)

KBUILD_CFLAGS += $(subdir-ccflags-y)

KBUILD_RUSTFLAGS += $(subdir-rustflags-y)

# Figure out what we need to build from the various variables

# ===========================================================================

# When an object is listed to be built compiled-in and modular,

# only build the compiled-in version

obj-m := $(filter-out $(obj-y),$(obj-m))

# Libraries are always collected in one lib file.

# Filter out objects already built-in

lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))

# Subdirectories we need to descend into

subdir-ym := $(sort $(subdir-y) $(subdir-m) \

$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))

# Handle objects in subdirs:

# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and

# foo/modules.order

# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order

#

# Generate modules.order to determine modorder. Unfortunately, we don't have

# information about ordering between -y and -m subdirs. Just put -y's first.

ifdef need-modorder

obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))

else

obj-m := $(filter-out %/, $(obj-m))

endif

ifdef need-builtin

obj-y := $(patsubst %/, %/built-in.a, $(obj-y))

else

obj-y := $(filter-out %/, $(obj-y))

endif

# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals

suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))

# List composite targets that are constructed by combining other targets

multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))

# List primitive targets that are compiled from source files

real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))

# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object

multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)

multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)

multi-obj-ym := $(multi-obj-y) $(multi-obj-m)

# Replace multi-part objects by their individual parts,

# including built-in.a from subdirectories

real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)

real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)

always-y += $(always-m)

# hostprogs-always-y += foo

# ... is a shorthand for

# hostprogs += foo

# always-y += foo

hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)

always-y += $(hostprogs-always-y) $(hostprogs-always-m)

# userprogs-always-y is likewise.

userprogs += $(userprogs-always-y) $(userprogs-always-m)

always-y += $(userprogs-always-y) $(userprogs-always-m)

# Add subdir path

ifneq ($(obj),.)

extra-y := $(addprefix $(obj)/,$(extra-y))

always-y := $(addprefix $(obj)/,$(always-y))

targets := $(addprefix $(obj)/,$(targets))

obj-m := $(addprefix $(obj)/,$(obj-m))

lib-y := $(addprefix $(obj)/,$(lib-y))

real-obj-y := $(addprefix $(obj)/,$(real-obj-y))

real-obj-m := $(addprefix $(obj)/,$(real-obj-m))

multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m))

subdir-ym := $(addprefix $(obj)/,$(subdir-ym))

endif

# Finds the multi-part object the current object will be linked into.

# If the object belongs to two or more multi-part objects, list them all.

modname-multi = $(sort $(foreach m,$(multi-obj-ym),\

$(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))

__modname = $(or $(modname-multi),$(basetarget))

modname = $(subst $(space),:,$(__modname))

modfile = $(addprefix $(obj)/,$(__modname))

# target with $(obj)/ and its suffix stripped

target-stem = $(basename $(patsubst $(obj)/%,%,$@))

# These flags are needed for modversions and compiling, so we define them here

# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will

# end up in (or would, if it gets compiled in)

name-fix-token = $(subst $(comma),_,$(subst -,_,$1))

name-fix = $(call stringify,$(call name-fix-token,$1))

basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))

modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \

-D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))

modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))

_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \

$(filter-out $(ccflags-remove-y), \

$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \

$(CFLAGS_$(target-stem).o))

_rust_flags = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \

$(filter-out $(rustflags-remove-y), \

$(KBUILD_RUSTFLAGS) $(rustflags-y)) \

$(RUSTFLAGS_$(target-stem).o))

_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \

$(filter-out $(asflags-remove-y), \

$(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \

$(AFLAGS_$(target-stem).o))

_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)

#

# Enable gcov profiling flags for a file, directory or for all files depending

# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL

# (in this order)

#

ifeq ($(CONFIG_GCOV_KERNEL),y)

_c_flags += $(if $(patsubst n%,, \

$(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(if $(is-kernel-object),$(CONFIG_GCOV_PROFILE_ALL))), \

$(CFLAGS_GCOV))

endif

#

# Enable address sanitizer flags for kernel except some files or directories

# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)

#

ifeq ($(CONFIG_KASAN),y)

ifneq ($(CONFIG_KASAN_HW_TAGS),y)

_c_flags += $(if $(patsubst n%,, \

$(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \

$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))

_rust_flags += $(if $(patsubst n%,, \

$(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \

$(RUSTFLAGS_KASAN))

endif

endif

ifeq ($(CONFIG_KMSAN),y)

_c_flags += $(if $(patsubst n%,, \

$(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)$(is-kernel-object)), \

$(CFLAGS_KMSAN))

_c_flags += $(if $(patsubst n%,, \

$(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)$(is-kernel-object)), \

, -mllvm -msan-disable-checks=1)

endif

ifeq ($(CONFIG_UBSAN),y)

_c_flags += $(if $(patsubst n%,, \

$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)$(is-kernel-object)), \

$(CFLAGS_UBSAN))

_c_flags += $(if $(patsubst n%,, \

$(UBSAN_SIGNED_WRAP_$(target-stem).o)$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SIGNED_WRAP)$(UBSAN_SANITIZE)$(is-kernel-object)), \

$(CFLAGS_UBSAN_SIGNED_WRAP))

endif

ifeq ($(CONFIG_KCOV),y)

_c_flags += $(if $(patsubst n%,, \

$(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \

$(CFLAGS_KCOV))

endif

#

# Enable KCSAN flags except some files or directories we don't want to check

# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)

#

ifeq ($(CONFIG_KCSAN),y)

_c_flags += $(if $(patsubst n%,, \

$(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)$(is-kernel-object)), \

$(CFLAGS_KCSAN))

# Some uninstrumented files provide implied barriers required to avoid false

# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.

_c_flags += $(if $(patsubst n%,, \

$(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \

-D__KCSAN_INSTRUMENT_BARRIERS__)

endif

# $(src) for including checkin headers from generated source files

# $(obj) for including generated headers from checkin source files

ifeq ($(KBUILD_EXTMOD),)

ifdef building_out_of_srctree

_c_flags += $(addprefix -I, $(src) $(obj))

_a_flags += $(addprefix -I, $(src) $(obj))

_cpp_flags += $(addprefix -I, $(src) $(obj))

endif

endif

# If $(is-kernel-object) is 'y', this object will be linked to vmlinux or modules

is-kernel-object = $(or $(part-of-builtin),$(part-of-module))

part-of-builtin = $(if $(filter $(basename $@).o, $(real-obj-y) $(lib-y)),y)

part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)

quiet_modtag = $(if $(part-of-module),[M], )

modkern_cflags = \

$(if $(part-of-module), \

$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \

$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))

modkern_rustflags = \

$(if $(part-of-module), \

$(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \

$(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))

modkern_aflags = $(if $(part-of-module), \

$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \

$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(modfile_flags))

c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \

-include $(srctree)/include/linux/compiler_types.h \

$(_c_flags) $(modkern_cflags) \

$(basename_flags) $(modname_flags)

rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg

a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \

$(_a_flags) $(modkern_aflags) $(modname_flags)

cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \

$(_cpp_flags)

ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))

ifdef CONFIG_OBJTOOL

objtool := $(objtree)/tools/objtool/objtool

objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label

objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr

objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake

objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt

objtool-args-$(CONFIG_FINEIBT) += --cfi

objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount

ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL

objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop

endif

objtool-args-$(CONFIG_UNWINDER_ORC) += --orc

objtool-args-$(CONFIG_MITIGATION_RETPOLINE) += --retpoline

objtool-args-$(CONFIG_MITIGATION_RETHUNK) += --rethunk

objtool-args-$(CONFIG_MITIGATION_SLS) += --sls

objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval

objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call

objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess

objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable

objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)

objtool-args = $(objtool-args-y) \

$(if $(delay-objtool), --link) \

$(if $(part-of-module), --module)

delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))

cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)

cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)

endif # CONFIG_OBJTOOL

# Useful for describing the dependency of composite objects

# Usage:

# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)

define multi_depend

$(foreach m, $1, \

$(eval $m: \

$(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))

endef

# Copy a file

# ===========================================================================

# 'cp' preserves permissions. If you use it to copy a file in read-only srctree,

# the copy would be read-only as well, leading to an error when executing the

# rule next time. Use 'cat' instead in order to generate a writable file.

quiet_cmd_copy = COPY $@

cmd_copy = cat $< > $@

$(obj)/%: $(src)/%_shipped

$(call cmd,copy)

# Commands useful for building a boot image

# ===========================================================================

#

# Use as following:

#

# target: source(s) FORCE

# $(if_changed,ld/objcopy/gzip)

#

# and add target to 'targets' so that we know we have to

# read in the saved command line

# Linking

# ---------------------------------------------------------------------------

quiet_cmd_ld = LD $@

cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@

# Archive

# ---------------------------------------------------------------------------

quiet_cmd_ar = AR $@

cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)

# Objcopy

# ---------------------------------------------------------------------------

quiet_cmd_objcopy = OBJCOPY $@

cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@

# Gzip

# ---------------------------------------------------------------------------

quiet_cmd_gzip = GZIP $@

cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@

# Bzip2

# ---------------------------------------------------------------------------

# Bzip2 and LZMA do not include size in file... so we have to fake that;

# append the size as a 32-bit littleendian number as gzip does.

size_append = printf $(shell \

dec_size=0; \

for F in $(real-prereqs); do \

fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \

dec_size=$$(expr $$dec_size + $$fsize); \

done; \

printf "%08x\n" $$dec_size | \

sed 's/\(..\)/\1 /g' | { \

read ch0 ch1 ch2 ch3; \

for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \

printf '%s%03o' '\\' $$((0x$$ch)); \

done; \

} \

)

quiet_cmd_file_size = GEN $@

cmd_file_size = $(size_append) > $@

quiet_cmd_bzip2 = BZIP2 $@

cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@

quiet_cmd_bzip2_with_size = BZIP2 $@

cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@

# Lzma

# ---------------------------------------------------------------------------

quiet_cmd_lzma = LZMA $@

cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@

quiet_cmd_lzma_with_size = LZMA $@

cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@

quiet_cmd_lzo = LZO $@

cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@

quiet_cmd_lzo_with_size = LZO $@

cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@

quiet_cmd_lz4 = LZ4 $@

cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@

quiet_cmd_lz4_with_size = LZ4 $@

cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \

$(size_append); } > $@

# U-Boot mkimage

# ---------------------------------------------------------------------------

MKIMAGE := $(srctree)/scripts/mkuboot.sh

# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces

# the number of overrides in arch makefiles

UIMAGE_ARCH ?= $(SRCARCH)

UIMAGE_COMPRESSION ?= $(or $(2),none)

UIMAGE_OPTS-y ?=

UIMAGE_TYPE ?= kernel

UIMAGE_LOADADDR ?= arch_must_set_this

UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)

UIMAGE_NAME ?= Linux-$(KERNELRELEASE)

quiet_cmd_uimage = UIMAGE $@

cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \

-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \

-T $(UIMAGE_TYPE) \

-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \

-n '$(UIMAGE_NAME)' -d $< $@

# Flat Image Tree (FIT)

# This allows for packaging of a kernel and all devicetrees files, using

# compression.

# ---------------------------------------------------------------------------

MAKE_FIT := $(srctree)/scripts/make_fit.py

# Use this to override the compression algorithm

FIT_COMPRESSION ?= gzip

quiet_cmd_fit = FIT $@

cmd_fit = $(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \

--name '$(UIMAGE_NAME)' \

$(if $(findstring 1,$(KBUILD_VERBOSE)),-v) \

$(if $(FIT_DECOMPOSE_DTBS),--decompose-dtbs) \

--compress $(FIT_COMPRESSION) -k $< @$(word 2,$^)

# XZ

# ---------------------------------------------------------------------------

# Use xzkern or xzkern_with_size to compress the kernel image and xzmisc to

# compress other things.

#

# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage

# of the kernel decompressor. A BCJ filter is used if it is available for

# the target architecture.

#

# xzkern_with_size also appends uncompressed size of the data using

# size_append. The .xz format has the size information available at the end

# of the file too, but it's in more complex format and it's good to avoid

# changing the part of the boot code that reads the uncompressed size.

# Note that the bytes added by size_append will make the xz tool think that

# the file is corrupt. This is expected.

#

# xzmisc doesn't use size_append, so it can be used to create normal .xz

# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very

# big dictionary would increase the memory usage too much in the multi-call

# decompression mode. A BCJ filter isn't used either.

quiet_cmd_xzkern = XZKERN $@

cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@

quiet_cmd_xzkern_with_size = XZKERN $@

cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \

$(size_append); } > $@

quiet_cmd_xzmisc = XZMISC $@

cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@

# ZSTD

# ---------------------------------------------------------------------------

# Appends the uncompressed size of the data using size_append. The .zst

# format has the size information available at the beginning of the file too,

# but it's in a more complex format and it's good to avoid changing the part

# of the boot code that reads the uncompressed size.

#

# Note that the bytes added by size_append will make the zstd tool think that

# the file is corrupt. This is expected.

#

# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of

# 128 MB. zstd22 is used for kernel compression because it is decompressed in a

# single pass, so zstd doesn't need to allocate a window buffer. When streaming

# decompression is used, like initramfs decompression, zstd22 should likely not

# be used because it would require zstd to allocate a 128 MB buffer.

quiet_cmd_zstd = ZSTD $@

cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@

quiet_cmd_zstd22 = ZSTD22 $@

cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@

quiet_cmd_zstd22_with_size = ZSTD22 $@

cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@

# ASM offsets

# ---------------------------------------------------------------------------

# Default sed regexp - multiline due to syntax constraints

#

# Use [:space:] because LLVM's integrated assembler inserts <tab> around

# the .ascii directive whereas GCC keeps the <space> as-is.

define sed-offsets

's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \

/^->/{s:->#\(.*\):/* \1 */:; \

s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \

s:->::; p;}'

endef

# Use filechk to avoid rebuilds when a header changes, but the resulting file

# does not

define filechk_offsets

echo "#ifndef $2"; \

echo "#define $2"; \

echo "/*"; \

echo " * DO NOT MODIFY."; \

echo " *"; \

echo " * This file was generated by Kbuild"; \

echo " */"; \

echo ""; \

sed -ne $(sed-offsets) < $<; \

echo ""; \

echo "#endif"

endef