[linux-2.6-block.git] / scripts / link-vmlinux.sh

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# link vmlinux
#
# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_OBJS) and
# $(KBUILD_VMLINUX_LIBS). Most are built-in.a files from top-level directories
# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
# $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
# (not within --whole-archive), and do not require symbol indexes added.
#
# vmlinux
#   ^
#   |
#   +--< $(KBUILD_VMLINUX_OBJS)
#   |    +--< init/built-in.a drivers/built-in.a mm/built-in.a + more
#   |
#   +--< $(KBUILD_VMLINUX_LIBS)
#   |    +--< lib/lib.a + more
#   |
#   +-< ${kallsymso} (see description in KALLSYMS section)
#
# vmlinux version (uname -v) cannot be updated during normal
# descending-into-subdirs phase since we do not yet know if we need to
# update vmlinux.
# Therefore this step is delayed until just before final link of vmlinux.
#
# System.map is generated to document addresses of all kernel symbols

# Error out on error
set -e

# Nice output in kbuild format
# Will be supressed by "make -s"
info()
{
	if [ "${quiet}" != "silent_" ]; then
		printf "  %-7s %s\n" "${1}" "${2}"
	fi
}

# Link of vmlinux.o used for section mismatch analysis
# ${1} output file
modpost_link()
{
	local objects

	objects="--whole-archive				\
		${KBUILD_VMLINUX_OBJS}				\
		--no-whole-archive				\
		--start-group					\
		${KBUILD_VMLINUX_LIBS}				\
		--end-group"

	${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects}
}

# Link of vmlinux
# ${1} - output file
# ${2}, ${3}, ... - optional extra .o files
vmlinux_link()
{
	local lds="${objtree}/${KBUILD_LDS}"
	local output=${1}
	local objects

	info LD ${output}

	# skip output file argument
	shift

	if [ "${SRCARCH}" != "um" ]; then
		objects="--whole-archive			\
			${KBUILD_VMLINUX_OBJS}			\
			--no-whole-archive			\
			--start-group				\
			${KBUILD_VMLINUX_LIBS}			\
			--end-group				\
			${@}"

		${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux}	\
			-o ${output}				\
			-T ${lds} ${objects}
	else
		objects="-Wl,--whole-archive			\
			${KBUILD_VMLINUX_OBJS}			\
			-Wl,--no-whole-archive			\
			-Wl,--start-group			\
			${KBUILD_VMLINUX_LIBS}			\
			-Wl,--end-group				\
			${@}"

		${CC} ${CFLAGS_vmlinux}				\
			-o ${output}				\
			-Wl,-T,${lds}				\
			${objects}				\
			-lutil -lrt -lpthread
		rm -f linux
	fi
}

# generate .BTF typeinfo from DWARF debuginfo
# ${1} - vmlinux image
# ${2} - file to dump raw BTF data into
gen_btf()
{
	local pahole_ver
	local bin_arch

	if ! [ -x "$(command -v ${PAHOLE})" ]; then
		info "BTF" "${1}: pahole (${PAHOLE}) is not available"
		return 1
	fi

	pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
	if [ "${pahole_ver}" -lt "113" ]; then
		info "BTF" "${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13"
		return 1
	fi

	info "BTF" ${2}
	vmlinux_link ${1}
	LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}

	# dump .BTF section into raw binary file to link with final vmlinux
	bin_arch=$(LANG=C ${OBJDUMP} -f ${1} | grep architecture | \
		cut -d, -f1 | cut -d' ' -f2)
	bin_format=$(LANG=C ${OBJDUMP} -f ${1} | grep 'file format' | \
		awk '{print $4}')
	${OBJCOPY} --dump-section .BTF=.btf.vmlinux.bin ${1} 2>/dev/null
	${OBJCOPY} -I binary -O ${bin_format} -B ${bin_arch} \
		--rename-section .data=.BTF .btf.vmlinux.bin ${2}
}

# Create ${2} .o file with all symbols from the ${1} object file
kallsyms()
{
	info KSYM ${2}
	local kallsymopt;

	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
		kallsymopt="${kallsymopt} --all-symbols"
	fi

	if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
		kallsymopt="${kallsymopt} --absolute-percpu"
	fi

	if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
		kallsymopt="${kallsymopt} --base-relative"
	fi

	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"

	local afile="`basename ${2} .o`.S"

	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
	${CC} ${aflags} -c -o ${2} ${afile}
}

# Perform one step in kallsyms generation, including temporary linking of
# vmlinux.
kallsyms_step()
{
	kallsymso_prev=${kallsymso}
	kallsymso=.tmp_kallsyms${1}.o
	kallsyms_vmlinux=.tmp_vmlinux${1}

	vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
	kallsyms ${kallsyms_vmlinux} ${kallsymso}
}

# Create map file with all symbols from ${1}
# See mksymap for additional details
mksysmap()
{
	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
}

sortextable()
{
	${objtree}/scripts/sortextable ${1}
}

# Delete output files in case of error
cleanup()
{
	rm -f .btf.*
	rm -f .tmp_System.map
	rm -f .tmp_kallsyms*
	rm -f .tmp_vmlinux*
	rm -f System.map
	rm -f vmlinux
	rm -f vmlinux.o
}

on_exit()
{
	if [ $? -ne 0 ]; then
		cleanup
	fi
}
trap on_exit EXIT

on_signals()
{
	exit 1
}
trap on_signals HUP INT QUIT TERM

#
#
# Use "make V=1" to debug this script
case "${KBUILD_VERBOSE}" in
*1*)
	set -x
	;;
esac

if [ "$1" = "clean" ]; then
	cleanup
	exit 0
fi

# We need access to CONFIG_ symbols
. include/config/auto.conf

# Update version
info GEN .version
if [ -r .version ]; then
	VERSION=$(expr 0$(cat .version) + 1)
	echo $VERSION > .version
else
	rm -f .version
	echo 1 > .version
fi;

# final build of init/
${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init

#link vmlinux.o
info LD vmlinux.o
modpost_link vmlinux.o

# modpost vmlinux.o to check for section mismatches
${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1

info MODINFO modules.builtin.modinfo
${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo

btf_vmlinux_bin_o=""
if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
	if gen_btf .tmp_vmlinux.btf .btf.vmlinux.bin.o ; then
		btf_vmlinux_bin_o=.btf.vmlinux.bin.o
	fi
fi

kallsymso=""
kallsymso_prev=""
kallsyms_vmlinux=""
if [ -n "${CONFIG_KALLSYMS}" ]; then

	# kallsyms support
	# Generate section listing all symbols and add it into vmlinux
	# It's a three step process:
	# 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
	#     but __kallsyms is empty.
	#     Running kallsyms on that gives us .tmp_kallsyms1.o with
	#     the right size
	# 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
	#     the right size, but due to the added section, some
	#     addresses have shifted.
	#     From here, we generate a correct .tmp_kallsyms2.o
	# 3)  That link may have expanded the kernel image enough that
	#     more linker branch stubs / trampolines had to be added, which
	#     introduces new names, which further expands kallsyms. Do another
	#     pass if that is the case. In theory it's possible this results
	#     in even more stubs, but unlikely.
	#     KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
	#     other bugs.
	# 4)  The correct ${kallsymso} is linked into the final vmlinux.
	#
	# a)  Verify that the System.map from vmlinux matches the map from
	#     ${kallsymso}.

	kallsyms_step 1
	kallsyms_step 2

	# step 3
	size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
	size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})

	if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
		kallsyms_step 3
	fi
fi

vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}

if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
	info SORTEX vmlinux
	sortextable vmlinux
fi

info SYSMAP System.map
mksysmap vmlinux System.map

# step a (see comment above)
if [ -n "${CONFIG_KALLSYMS}" ]; then
	mksysmap ${kallsyms_vmlinux} .tmp_System.map

	if ! cmp -s System.map .tmp_System.map; then
		echo >&2 Inconsistent kallsyms data
		echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
		exit 1
	fi
fi
Commit	Line	Data
	1	#!/bin/sh
	2	# SPDX-License-Identifier: GPL-2.0
	3	#
	4	# link vmlinux
	5	#
	6	# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_OBJS) and
	7	# $(KBUILD_VMLINUX_LIBS). Most are built-in.a files from top-level directories
	8	# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
	9	# $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
	10	# (not within --whole-archive), and do not require symbol indexes added.
	11	#
	12	# vmlinux
	13	# ^
	14	# \|
	15	# +--< $(KBUILD_VMLINUX_OBJS)
	16	# \| +--< init/built-in.a drivers/built-in.a mm/built-in.a + more
	17	# \|
	18	# +--< $(KBUILD_VMLINUX_LIBS)
	19	# \| +--< lib/lib.a + more
	20	# \|
	21	# +-< ${kallsymso} (see description in KALLSYMS section)
	22	#
	23	# vmlinux version (uname -v) cannot be updated during normal
	24	# descending-into-subdirs phase since we do not yet know if we need to
	25	# update vmlinux.
	26	# Therefore this step is delayed until just before final link of vmlinux.
	27	#
	28	# System.map is generated to document addresses of all kernel symbols
	29
	30	# Error out on error
	31	set -e
	32
	33	# Nice output in kbuild format
	34	# Will be supressed by "make -s"
	35	info()
	36	{
	37	if [ "${quiet}" != "silent_" ]; then
	38	printf " %-7s %s\n" "${1}" "${2}"
	39	fi
	40	}
	41
	42	# Link of vmlinux.o used for section mismatch analysis
	43	# ${1} output file
	44	modpost_link()
	45	{
	46	local objects
	47
	48	objects="--whole-archive \
	49	${KBUILD_VMLINUX_OBJS} \
	50	--no-whole-archive \
	51	--start-group \
	52	${KBUILD_VMLINUX_LIBS} \
	53	--end-group"
	54
	55	${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects}
	56	}
	57
	58	# Link of vmlinux
	59	# ${1} - output file
	60	# ${2}, ${3}, ... - optional extra .o files
	61	vmlinux_link()
	62	{
	63	local lds="${objtree}/${KBUILD_LDS}"
	64	local output=${1}
	65	local objects
	66
	67	info LD ${output}
	68
	69	# skip output file argument
	70	shift
	71
	72	if [ "${SRCARCH}" != "um" ]; then
	73	objects="--whole-archive \
	74	${KBUILD_VMLINUX_OBJS} \
	75	--no-whole-archive \
	76	--start-group \
	77	${KBUILD_VMLINUX_LIBS} \
	78	--end-group \
	79	${@}"
	80
	81	${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
	82	-o ${output} \
	83	-T ${lds} ${objects}
	84	else
	85	objects="-Wl,--whole-archive \
	86	${KBUILD_VMLINUX_OBJS} \
	87	-Wl,--no-whole-archive \
	88	-Wl,--start-group \
	89	${KBUILD_VMLINUX_LIBS} \
	90	-Wl,--end-group \
	91	${@}"
	92
	93	${CC} ${CFLAGS_vmlinux} \
	94	-o ${output} \
	95	-Wl,-T,${lds} \
	96	${objects} \
	97	-lutil -lrt -lpthread
	98	rm -f linux
	99	fi
	100	}
	101
	102	# generate .BTF typeinfo from DWARF debuginfo
	103	# ${1} - vmlinux image
	104	# ${2} - file to dump raw BTF data into
	105	gen_btf()
	106	{
	107	local pahole_ver
	108	local bin_arch
	109
	110	if ! [ -x "$(command -v ${PAHOLE})" ]; then
	111	info "BTF" "${1}: pahole (${PAHOLE}) is not available"
	112	return 1
	113	fi
	114
	115	pahole_ver=$(${PAHOLE} --version \| sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
	116	if [ "${pahole_ver}" -lt "113" ]; then
	117	info "BTF" "${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13"
	118	return 1
	119	fi
	120
	121	info "BTF" ${2}
	122	vmlinux_link ${1}
	123	LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
	124
	125	# dump .BTF section into raw binary file to link with final vmlinux
	126	bin_arch=$(LANG=C ${OBJDUMP} -f ${1} \| grep architecture \| \
	127	cut -d, -f1 \| cut -d' ' -f2)
	128	bin_format=$(LANG=C ${OBJDUMP} -f ${1} \| grep 'file format' \| \
	129	awk '{print $4}')
	130	${OBJCOPY} --dump-section .BTF=.btf.vmlinux.bin ${1} 2>/dev/null
	131	${OBJCOPY} -I binary -O ${bin_format} -B ${bin_arch} \
	132	--rename-section .data=.BTF .btf.vmlinux.bin ${2}
	133	}
	134
	135	# Create ${2} .o file with all symbols from the ${1} object file
	136	kallsyms()
	137	{
	138	info KSYM ${2}
	139	local kallsymopt;
	140
	141	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
	142	kallsymopt="${kallsymopt} --all-symbols"
	143	fi
	144
	145	if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
	146	kallsymopt="${kallsymopt} --absolute-percpu"
	147	fi
	148
	149	if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
	150	kallsymopt="${kallsymopt} --base-relative"
	151	fi
	152
	153	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
	154	${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
	155
	156	local afile="`basename ${2} .o`.S"
	157
	158	${NM} -n ${1} \| scripts/kallsyms ${kallsymopt} > ${afile}
	159	${CC} ${aflags} -c -o ${2} ${afile}
	160	}
	161
	162	# Perform one step in kallsyms generation, including temporary linking of
	163	# vmlinux.
	164	kallsyms_step()
	165	{
	166	kallsymso_prev=${kallsymso}
	167	kallsymso=.tmp_kallsyms${1}.o
	168	kallsyms_vmlinux=.tmp_vmlinux${1}
	169
	170	vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
	171	kallsyms ${kallsyms_vmlinux} ${kallsymso}
	172	}
	173
	174	# Create map file with all symbols from ${1}
	175	# See mksymap for additional details
	176	mksysmap()
	177	{
	178	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
	179	}
	180
	181	sortextable()
	182	{
	183	${objtree}/scripts/sortextable ${1}
	184	}
	185
	186	# Delete output files in case of error
	187	cleanup()
	188	{
	189	rm -f .btf.*
	190	rm -f .tmp_System.map
	191	rm -f .tmp_kallsyms*
	192	rm -f .tmp_vmlinux*
	193	rm -f System.map
	194	rm -f vmlinux
	195	rm -f vmlinux.o
	196	}
	197
	198	on_exit()
	199	{
	200	if [ $? -ne 0 ]; then
	201	cleanup
	202	fi
	203	}
	204	trap on_exit EXIT
	205
	206	on_signals()
	207	{
	208	exit 1
	209	}
	210	trap on_signals HUP INT QUIT TERM
	211
	212	#
	213	#
	214	# Use "make V=1" to debug this script
	215	case "${KBUILD_VERBOSE}" in
	216	1)
	217	set -x
	218	;;
	219	esac
	220
	221	if [ "$1" = "clean" ]; then
	222	cleanup
	223	exit 0
	224	fi
	225
	226	# We need access to CONFIG_ symbols
	227	. include/config/auto.conf
	228
	229	# Update version
	230	info GEN .version
	231	if [ -r .version ]; then
	232	VERSION=$(expr 0$(cat .version) + 1)
	233	echo $VERSION > .version
	234	else
	235	rm -f .version
	236	echo 1 > .version
	237	fi;
	238
	239	# final build of init/
	240	${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
	241
	242	#link vmlinux.o
	243	info LD vmlinux.o
	244	modpost_link vmlinux.o
	245
	246	# modpost vmlinux.o to check for section mismatches
	247	${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1
	248
	249	info MODINFO modules.builtin.modinfo
	250	${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
	251
	252	btf_vmlinux_bin_o=""
	253	if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
	254	if gen_btf .tmp_vmlinux.btf .btf.vmlinux.bin.o ; then
	255	btf_vmlinux_bin_o=.btf.vmlinux.bin.o
	256	fi
	257	fi
	258
	259	kallsymso=""
	260	kallsymso_prev=""
	261	kallsyms_vmlinux=""
	262	if [ -n "${CONFIG_KALLSYMS}" ]; then
	263
	264	# kallsyms support
	265	# Generate section listing all symbols and add it into vmlinux
	266	# It's a three step process:
	267	# 1) Link .tmp_vmlinux1 so it has all symbols and sections,
	268	# but __kallsyms is empty.
	269	# Running kallsyms on that gives us .tmp_kallsyms1.o with
	270	# the right size
	271	# 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
	272	# the right size, but due to the added section, some
	273	# addresses have shifted.
	274	# From here, we generate a correct .tmp_kallsyms2.o
	275	# 3) That link may have expanded the kernel image enough that
	276	# more linker branch stubs / trampolines had to be added, which
	277	# introduces new names, which further expands kallsyms. Do another
	278	# pass if that is the case. In theory it's possible this results
	279	# in even more stubs, but unlikely.
	280	# KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
	281	# other bugs.
	282	# 4) The correct ${kallsymso} is linked into the final vmlinux.
	283	#
	284	# a) Verify that the System.map from vmlinux matches the map from
	285	# ${kallsymso}.
	286
	287	kallsyms_step 1
	288	kallsyms_step 2
	289
	290	# step 3
	291	size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
	292	size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
	293
	294	if [ $size1 -ne $size2 ] \|\| [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
	295	kallsyms_step 3
	296	fi
	297	fi
	298
	299	vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
	300
	301	if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
	302	info SORTEX vmlinux
	303	sortextable vmlinux
	304	fi
	305
	306	info SYSMAP System.map
	307	mksysmap vmlinux System.map
	308
	309	# step a (see comment above)
	310	if [ -n "${CONFIG_KALLSYMS}" ]; then
	311	mksysmap ${kallsyms_vmlinux} .tmp_System.map
	312
	313	if ! cmp -s System.map .tmp_System.map; then
	314	echo >&2 Inconsistent kallsyms data
	315	echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
	316	exit 1
	317	fi
	318	fi