[mirror_ubuntu-bionic-kernel.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_INIT) and
# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.o files
# from top-level directories in the kernel tree, others are specified in
# arch/$(ARCH)/Makefile. Ordering when linking is important, and
# $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives
# which are linked conditionally (not within --whole-archive), and do not
# require symbol indexes added.
#
# vmlinux
#   ^
#   |
#   +-< $(KBUILD_VMLINUX_INIT)
#   |   +--< init/version.o + more
#   |
#   +--< $(KBUILD_VMLINUX_MAIN)
#   |    +--< drivers/built-in.o mm/built-in.o + 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
}

# Thin archive build here makes a final archive with symbol table and indexes
# from vmlinux objects INIT and MAIN, which can be used as input to linker.
# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes
# added.
#
# Traditional incremental style of link does not require this step
#
# built-in.o output file
#
archive_builtin()
{
	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
		info AR built-in.o
		rm -f built-in.o;
		${AR} rcsTP${KBUILD_ARFLAGS} built-in.o			\
					${KBUILD_VMLINUX_INIT}		\
					${KBUILD_VMLINUX_MAIN}
	fi
}

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

	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
		objects="--whole-archive				\
			built-in.o					\
			--no-whole-archive				\
			--start-group					\
			${KBUILD_VMLINUX_LIBS}				\
			--end-group"
	else
		objects="${KBUILD_VMLINUX_INIT}				\
			--start-group					\
			${KBUILD_VMLINUX_MAIN}				\
			${KBUILD_VMLINUX_LIBS}				\
			--end-group"
	fi
	${LD} ${LDFLAGS} -r -o ${1} ${objects}
}

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

	if [ "${SRCARCH}" != "um" ]; then
		if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
			objects="--whole-archive			\
				built-in.o				\
				--no-whole-archive			\
				--start-group				\
				${KBUILD_VMLINUX_LIBS}			\
				--end-group				\
				${1}"
		else
			objects="${KBUILD_VMLINUX_INIT}			\
				--start-group				\
				${KBUILD_VMLINUX_MAIN}			\
				${KBUILD_VMLINUX_LIBS}			\
				--end-group				\
				${1}"
		fi

		${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}		\
			-T ${lds} ${objects}
	else
		if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
			objects="-Wl,--whole-archive			\
				built-in.o				\
				-Wl,--no-whole-archive			\
				-Wl,--start-group			\
				${KBUILD_VMLINUX_LIBS}			\
				-Wl,--end-group				\
				${1}"
		else
			objects="${KBUILD_VMLINUX_INIT}			\
				-Wl,--start-group			\
				${KBUILD_VMLINUX_MAIN}			\
				${KBUILD_VMLINUX_LIBS}			\
				-Wl,--end-group				\
				${1}"
		fi

		${CC} ${CFLAGS_vmlinux} -o ${2}				\
			-Wl,-T,${lds}					\
			${objects}					\
			-lutil -lrt -lpthread
		rm -f linux
	fi
}


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

	if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
		kallsymopt="${kallsymopt} --symbol-prefix=_"
	fi

	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}
}

# 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 .tmp_System.map
	rm -f .tmp_kallsyms*
	rm -f .tmp_vmlinux*
	rm -f built-in.o
	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
case "${KCONFIG_CONFIG}" in
*/*)
	. "${KCONFIG_CONFIG}"
	;;
*)
	# Force using a file from the current directory
	. "./${KCONFIG_CONFIG}"
esac

# 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 GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"

archive_builtin

#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" vmlinux.o

kallsymso=""
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}.

	kallsymso=.tmp_kallsyms2.o
	kallsyms_vmlinux=.tmp_vmlinux2

	# step 1
	vmlinux_link "" .tmp_vmlinux1
	kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o

	# step 2
	vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
	kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o

	# step 3
	size1=$(stat -c "%s" .tmp_kallsyms1.o)
	size2=$(stat -c "%s" .tmp_kallsyms2.o)

	if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
		kallsymso=.tmp_kallsyms3.o
		kallsyms_vmlinux=.tmp_vmlinux3

		vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3

		kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
	fi
fi

info LD vmlinux
vmlinux_link "${kallsymso}" vmlinux

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
1f2bfbd0	1	#!/bin/sh
b2441318	2	# SPDX-License-Identifier: GPL-2.0
1f2bfbd0 SR	3	#
	4	# link vmlinux
	5	#
	6	# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
3a166fc2 NP	7	# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.o files
	8	# from top-level directories in the kernel tree, others are specified in
	9	# arch/$(ARCH)/Makefile. Ordering when linking is important, and
	10	# $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives
	11	# which are linked conditionally (not within --whole-archive), and do not
	12	# require symbol indexes added.
1f2bfbd0 SR	13	#
	14	# vmlinux
	15	# ^
	16	# \|
	17	# +-< $(KBUILD_VMLINUX_INIT)
	18	# \| +--< init/version.o + more
	19	# \|
	20	# +--< $(KBUILD_VMLINUX_MAIN)
	21	# \| +--< drivers/built-in.o mm/built-in.o + more
	22	# \|
3a166fc2 NP	23	# +--< $(KBUILD_VMLINUX_LIBS)
	24	# \| +--< lib/lib.a + more
	25	# \|
1f2bfbd0 SR	26	# +-< ${kallsymso} (see description in KALLSYMS section)
	27	#
	28	# vmlinux version (uname -v) cannot be updated during normal
	29	# descending-into-subdirs phase since we do not yet know if we need to
	30	# update vmlinux.
	31	# Therefore this step is delayed until just before final link of vmlinux.
	32	#
	33	# System.map is generated to document addresses of all kernel symbols
	34
	35	# Error out on error
	36	set -e
	37
	38	# Nice output in kbuild format
	39	# Will be supressed by "make -s"
	40	info()
	41	{
	42	if [ "${quiet}" != "silent_" ]; then
	43	printf " %-7s %s\n" ${1} ${2}
	44	fi
	45	}
	46
3a166fc2 NP	47	# Thin archive build here makes a final archive with symbol table and indexes
	48	# from vmlinux objects INIT and MAIN, which can be used as input to linker.
	49	# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes
	50	# added.
a5967db9 SR	51	#
	52	# Traditional incremental style of link does not require this step
	53	#
	54	# built-in.o output file
	55	#
	56	archive_builtin()
	57	{
	58	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
	59	info AR built-in.o
	60	rm -f built-in.o;
9a6cfca4	61	${AR} rcsTP${KBUILD_ARFLAGS} built-in.o \
a5967db9 SR	62	${KBUILD_VMLINUX_INIT} \
	63	${KBUILD_VMLINUX_MAIN}
	64	fi
	65	}
	66
1f2bfbd0 SR	67	# Link of vmlinux.o used for section mismatch analysis
	68	# ${1} output file
	69	modpost_link()
	70	{
a5967db9 SR	71	local objects
	72
	73	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
3a166fc2 NP	74	objects="--whole-archive \
	75	built-in.o \
	76	--no-whole-archive \
	77	--start-group \
	78	${KBUILD_VMLINUX_LIBS} \
	79	--end-group"
a5967db9 SR	80	else
	81	objects="${KBUILD_VMLINUX_INIT} \
	82	--start-group \
	83	${KBUILD_VMLINUX_MAIN} \
3a166fc2	84	${KBUILD_VMLINUX_LIBS} \
a5967db9 SR	85	--end-group"
	86	fi
	87	${LD} ${LDFLAGS} -r -o ${1} ${objects}
1f2bfbd0 SR	88	}
	89
	90	# Link of vmlinux
	91	# ${1} - optional extra .o files
	92	# ${2} - output file
	93	vmlinux_link()
	94	{
	95	local lds="${objtree}/${KBUILD_LDS}"
a5967db9	96	local objects
1f2bfbd0 SR	97
1f2bfbd0 SR	98	if [ "${SRCARCH}" != "um" ]; then
a5967db9	99	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
3a166fc2 NP	100	objects="--whole-archive \
	101	built-in.o \
	102	--no-whole-archive \
	103	--start-group \
	104	${KBUILD_VMLINUX_LIBS} \
	105	--end-group \
	106	${1}"
a5967db9 SR	107	else
	108	objects="${KBUILD_VMLINUX_INIT} \
	109	--start-group \
	110	${KBUILD_VMLINUX_MAIN} \
3a166fc2	111	${KBUILD_VMLINUX_LIBS} \
a5967db9 SR	112	--end-group \
	113	${1}"
	114	fi
	115
	116	${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
	117	-T ${lds} ${objects}
1f2bfbd0	118	else
a5967db9	119	if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
3a166fc2 NP	120	objects="-Wl,--whole-archive \
	121	built-in.o \
	122	-Wl,--no-whole-archive \
	123	-Wl,--start-group \
	124	${KBUILD_VMLINUX_LIBS} \
	125	-Wl,--end-group \
	126	${1}"
a5967db9 SR	127	else
	128	objects="${KBUILD_VMLINUX_INIT} \
	129	-Wl,--start-group \
	130	${KBUILD_VMLINUX_MAIN} \
3a166fc2	131	${KBUILD_VMLINUX_LIBS} \
a5967db9 SR	132	-Wl,--end-group \
	133	${1}"
	134	fi
	135
	136	${CC} ${CFLAGS_vmlinux} -o ${2} \
	137	-Wl,-T,${lds} \
	138	${objects} \
	139	-lutil -lrt -lpthread
1f2bfbd0 SR	140	rm -f linux
	141	fi
	142	}
	143
	144
	145	# Create ${2} .o file with all symbols from the ${1} object file
	146	kallsyms()
	147	{
	148	info KSYM ${2}
	149	local kallsymopt;
	150
b92021b0 RR	151	if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
b92021b0 RR	152	kallsymopt="${kallsymopt} --symbol-prefix=_"
6895f97e JH	153	fi
6895f97e JH	154
1f2bfbd0	155	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
6895f97e	156	kallsymopt="${kallsymopt} --all-symbols"
1f2bfbd0 SR	157	fi
1f2bfbd0 SR	158
4d5d5664	159	if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
c6bda7c9 RR	160	kallsymopt="${kallsymopt} --absolute-percpu"
	161	fi
	162
2213e9a6 AB	163	if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
	164	kallsymopt="${kallsymopt} --base-relative"
	165	fi
	166
00e6c28c SR	167	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
00e6c28c SR	168	${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
1f2bfbd0	169
a0439342 AB	170	local afile="`basename ${2} .o`.S"
	171
	172	${NM} -n ${1} \| scripts/kallsyms ${kallsymopt} > ${afile}
	173	${CC} ${aflags} -c -o ${2} ${afile}
1f2bfbd0 SR	174	}
	175
	176	# Create map file with all symbols from ${1}
	177	# See mksymap for additional details
	178	mksysmap()
	179	{
	180	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
	181	}
	182
1347a2ce LT	183	sortextable()
	184	{
	185	${objtree}/scripts/sortextable ${1}
	186	}
	187
1f2bfbd0	188	# Delete output files in case of error
1f2bfbd0 SR	189	cleanup()
1f2bfbd0 SR	190	{
1f2bfbd0 SR	191	rm -f .tmp_System.map
1f2bfbd0 SR	192	rm -f .tmp_kallsyms*
1f2bfbd0	193	rm -f .tmp_vmlinux*
a5967db9	194	rm -f built-in.o
1f2bfbd0 SR	195	rm -f System.map
	196	rm -f vmlinux
	197	rm -f vmlinux.o
	198	}
	199
ab160dbb SB	200	on_exit()
	201	{
	202	if [ $? -ne 0 ]; then
	203	cleanup
	204	fi
	205	}
	206	trap on_exit EXIT
	207
	208	on_signals()
	209	{
	210	exit 1
	211	}
	212	trap on_signals HUP INT QUIT TERM
	213
1f2bfbd0 SR	214	#
	215	#
	216	# Use "make V=1" to debug this script
	217	case "${KBUILD_VERBOSE}" in
	218	1)
	219	set -x
	220	;;
	221	esac
	222
	223	if [ "$1" = "clean" ]; then
	224	cleanup
	225	exit 0
	226	fi
	227
	228	# We need access to CONFIG_ symbols
423a8155 MM	229	case "${KCONFIG_CONFIG}" in
	230	/)
	231	. "${KCONFIG_CONFIG}"
	232	;;
	233	*)
	234	# Force using a file from the current directory
	235	. "./${KCONFIG_CONFIG}"
	236	esac
1f2bfbd0	237
1f2bfbd0 SR	238	# Update version
1f2bfbd0 SR	239	info GEN .version
278ae604 MY	240	if [ -r .version ]; then
	241	VERSION=$(expr 0$(cat .version) + 1)
	242	echo $VERSION > .version
1f2bfbd0	243	else
278ae604 MY	244	rm -f .version
278ae604 MY	245	echo 1 > .version
1f2bfbd0 SR	246	fi;
	247
	248	# final build of init/
6b90bd4b	249	${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
1f2bfbd0	250
abac4c89 NP	251	archive_builtin
	252
	253	#link vmlinux.o
	254	info LD vmlinux.o
	255	modpost_link vmlinux.o
	256
	257	# modpost vmlinux.o to check for section mismatches
	258	${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
	259
1f2bfbd0 SR	260	kallsymso=""
	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
7e2b37c9 NP	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.
1f2bfbd0 SR	283	#
	284	# a) Verify that the System.map from vmlinux matches the map from
	285	# ${kallsymso}.
	286
	287	kallsymso=.tmp_kallsyms2.o
	288	kallsyms_vmlinux=.tmp_vmlinux2
	289
	290	# step 1
	291	vmlinux_link "" .tmp_vmlinux1
	292	kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
	293
	294	# step 2
	295	vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
	296	kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
	297
7e2b37c9 NP	298	# step 3
	299	size1=$(stat -c "%s" .tmp_kallsyms1.o)
	300	size2=$(stat -c "%s" .tmp_kallsyms2.o)
	301
	302	if [ $size1 -ne $size2 ] \|\| [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
1f2bfbd0 SR	303	kallsymso=.tmp_kallsyms3.o
	304	kallsyms_vmlinux=.tmp_vmlinux3
	305
	306	vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
	307
	308	kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
	309	fi
	310	fi
	311
	312	info LD vmlinux
	313	vmlinux_link "${kallsymso}" vmlinux
	314
1347a2ce LT	315	if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
	316	info SORTEX vmlinux
	317	sortextable vmlinux
	318	fi
	319
1f2bfbd0 SR	320	info SYSMAP System.map
	321	mksysmap vmlinux System.map
	322
	323	# step a (see comment above)
	324	if [ -n "${CONFIG_KALLSYMS}" ]; then
	325	mksysmap ${kallsyms_vmlinux} .tmp_System.map
	326
	327	if ! cmp -s System.map .tmp_System.map; then
5369f550	328	echo >&2 Inconsistent kallsyms data
367e43c5	329	echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
1f2bfbd0 SR	330	exit 1
	331	fi
	332	fi