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_INIT) and
  7# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.a files
  8# from top-level directories in the kernel tree, others are specified in
  9# arch/$(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.
 13#
 14# vmlinux
 15#   ^
 16#   |
 17#   +-< $(KBUILD_VMLINUX_INIT)
 18#   |   +--< init/version.o + more
 19#   |
 20#   +--< $(KBUILD_VMLINUX_MAIN)
 21#   |    +--< drivers/built-in.a mm/built-in.a + more
 22#   |
 23#   +--< $(KBUILD_VMLINUX_LIBS)
 24#   |    +--< lib/lib.a + more
 25#   |
 26#   +-< ${kallsymso} (see description in KALLSYMS section)
 27#
 28# vmlinux version (uname -v) cannot be updated during normal
 29# descending-into-subdirs phase since we do not yet know if we need to
 30# update vmlinux.
 31# Therefore this step is delayed until just before final link of vmlinux.
 32#
 33# System.map is generated to document addresses of all kernel symbols
 34
 35# Error out on error
 36set -e
 37
 38# Nice output in kbuild format
 39# Will be supressed by "make -s"
 40info()
 41{
 42	if [ "${quiet}" != "silent_" ]; then
 43		printf "  %-7s %s\n" ${1} ${2}
 44	fi
 45}
 46
 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.
 51#
 52# Traditional incremental style of link does not require this step
 53#
 54# built-in.a output file
 55#
 56archive_builtin()
 57{
 58	info AR built-in.a
 59	rm -f built-in.a;
 60	${AR} rcsTP${KBUILD_ARFLAGS} built-in.a			\
 61				${KBUILD_VMLINUX_INIT}		\
 62				${KBUILD_VMLINUX_MAIN}
 63}
 64
 65# Link of vmlinux.o used for section mismatch analysis
 66# ${1} output file
 67modpost_link()
 68{
 69	local objects
 70
 71	objects="--whole-archive				\
 72		built-in.a					\
 73		--no-whole-archive				\
 74		--start-group					\
 75		${KBUILD_VMLINUX_LIBS}				\
 76		--end-group"
 77
 78	${LD} ${LDFLAGS} -r -o ${1} ${objects}
 79}
 80
 81# Link of vmlinux
 82# ${1} - optional extra .o files
 83# ${2} - output file
 84vmlinux_link()
 85{
 86	local lds="${objtree}/${KBUILD_LDS}"
 
 87	local objects
 88
 
 
 
 
 
 89	if [ "${SRCARCH}" != "um" ]; then
 90		objects="--whole-archive			\
 91			built-in.a				\
 92			--no-whole-archive			\
 93			--start-group				\
 94			${KBUILD_VMLINUX_LIBS}			\
 95			--end-group				\
 96			${1}"
 97
 98		${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}	\
 
 99			-T ${lds} ${objects}
100	else
101		objects="-Wl,--whole-archive			\
102			built-in.a				\
103			-Wl,--no-whole-archive			\
104			-Wl,--start-group			\
105			${KBUILD_VMLINUX_LIBS}			\
106			-Wl,--end-group				\
107			${1}"
108
109		${CC} ${CFLAGS_vmlinux} -o ${2}			\
 
110			-Wl,-T,${lds}				\
111			${objects}				\
112			-lutil -lrt -lpthread
113		rm -f linux
114	fi
115}
116
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
117
118# Create ${2} .o file with all symbols from the ${1} object file
119kallsyms()
120{
121	info KSYM ${2}
122	local kallsymopt;
123
124	if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
125		kallsymopt="${kallsymopt} --symbol-prefix=_"
126	fi
127
128	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
129		kallsymopt="${kallsymopt} --all-symbols"
130	fi
131
132	if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
133		kallsymopt="${kallsymopt} --absolute-percpu"
134	fi
135
136	if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
137		kallsymopt="${kallsymopt} --base-relative"
138	fi
139
140	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
141		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
142
143	local afile="`basename ${2} .o`.S"
144
145	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
146	${CC} ${aflags} -c -o ${2} ${afile}
147}
148
 
 
 
 
 
 
 
 
 
 
 
 
149# Create map file with all symbols from ${1}
150# See mksymap for additional details
151mksysmap()
152{
153	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
154}
155
156sortextable()
157{
158	${objtree}/scripts/sortextable ${1}
159}
160
161# Delete output files in case of error
162cleanup()
163{
 
164	rm -f .tmp_System.map
165	rm -f .tmp_kallsyms*
166	rm -f .tmp_vmlinux*
167	rm -f built-in.a
168	rm -f System.map
169	rm -f vmlinux
170	rm -f vmlinux.o
171}
172
173on_exit()
174{
175	if [ $? -ne 0 ]; then
176		cleanup
177	fi
178}
179trap on_exit EXIT
180
181on_signals()
182{
183	exit 1
184}
185trap on_signals HUP INT QUIT TERM
186
187#
188#
189# Use "make V=1" to debug this script
190case "${KBUILD_VERBOSE}" in
191*1*)
192	set -x
193	;;
194esac
195
196if [ "$1" = "clean" ]; then
197	cleanup
198	exit 0
199fi
200
201# We need access to CONFIG_ symbols
202case "${KCONFIG_CONFIG}" in
203*/*)
204	. "${KCONFIG_CONFIG}"
205	;;
206*)
207	# Force using a file from the current directory
208	. "./${KCONFIG_CONFIG}"
209esac
210
211# Update version
212info GEN .version
213if [ -r .version ]; then
214	VERSION=$(expr 0$(cat .version) + 1)
215	echo $VERSION > .version
216else
217	rm -f .version
218	echo 1 > .version
219fi;
220
221# final build of init/
222${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
223
224archive_builtin
225
226#link vmlinux.o
227info LD vmlinux.o
228modpost_link vmlinux.o
229
230# modpost vmlinux.o to check for section mismatches
231${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
 
 
 
 
 
 
 
 
 
 
232
233kallsymso=""
 
234kallsyms_vmlinux=""
235if [ -n "${CONFIG_KALLSYMS}" ]; then
236
237	# kallsyms support
238	# Generate section listing all symbols and add it into vmlinux
239	# It's a three step process:
240	# 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
241	#     but __kallsyms is empty.
242	#     Running kallsyms on that gives us .tmp_kallsyms1.o with
243	#     the right size
244	# 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
245	#     the right size, but due to the added section, some
246	#     addresses have shifted.
247	#     From here, we generate a correct .tmp_kallsyms2.o
248	# 3)  That link may have expanded the kernel image enough that
249	#     more linker branch stubs / trampolines had to be added, which
250	#     introduces new names, which further expands kallsyms. Do another
251	#     pass if that is the case. In theory it's possible this results
252	#     in even more stubs, but unlikely.
253	#     KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
254	#     other bugs.
255	# 4)  The correct ${kallsymso} is linked into the final vmlinux.
256	#
257	# a)  Verify that the System.map from vmlinux matches the map from
258	#     ${kallsymso}.
259
260	kallsymso=.tmp_kallsyms2.o
261	kallsyms_vmlinux=.tmp_vmlinux2
262
263	# step 1
264	vmlinux_link "" .tmp_vmlinux1
265	kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
266
267	# step 2
268	vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
269	kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
270
271	# step 3
272	size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o)
273	size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o)
274
275	if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
276		kallsymso=.tmp_kallsyms3.o
277		kallsyms_vmlinux=.tmp_vmlinux3
278
279		vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
280
281		kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
282	fi
283fi
284
285info LD vmlinux
286vmlinux_link "${kallsymso}" vmlinux
287
288if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
289	info SORTEX vmlinux
290	sortextable vmlinux
291fi
292
293info SYSMAP System.map
294mksysmap vmlinux System.map
295
296# step a (see comment above)
297if [ -n "${CONFIG_KALLSYMS}" ]; then
298	mksysmap ${kallsyms_vmlinux} .tmp_System.map
299
300	if ! cmp -s System.map .tmp_System.map; then
301		echo >&2 Inconsistent kallsyms data
302		echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
303		exit 1
304	fi
305fi

  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#   +-< ${kallsymso} (see description in KALLSYMS section)
 22#
 23# vmlinux version (uname -v) cannot be updated during normal
 24# descending-into-subdirs phase since we do not yet know if we need to
 25# update vmlinux.
 26# Therefore this step is delayed until just before final link of vmlinux.
 27#
 28# System.map is generated to document addresses of all kernel symbols
 29
 30# Error out on error
 31set -e
 32
 33# Nice output in kbuild format
 34# Will be supressed by "make -s"
 35info()
 36{
 37	if [ "${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
 44modpost_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}, ${3}, ... - optional extra .o files
 61vmlinux_link()
 62{
 63	local lds="${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# ${2} - file to dump raw BTF data into
105gen_btf()
106{
107	local pahole_ver
108	local bin_arch
109
110	if ! [ -x "$(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
136kallsyms()
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} ${afile}
160}
161
162# Perform one step in kallsyms generation, including temporary linking of
163# vmlinux.
164kallsyms_step()
165{
166	kallsymso_prev=${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
176mksysmap()
177{
178	${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
179}
180
181sortextable()
182{
183	${objtree}/scripts/sortextable ${1}
184}
185
186# Delete output files in case of error
187cleanup()
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
198on_exit()
199{
200	if [ $? -ne 0 ]; then
201		cleanup
202	fi
203}
204trap on_exit EXIT
205
206on_signals()
207{
208	exit 1
209}
210trap on_signals HUP INT QUIT TERM
211
212#
213#
214# Use "make V=1" to debug this script
215case "${KBUILD_VERBOSE}" in
216*1*)
217	set -x
218	;;
219esac
220
221if [ "$1" = "clean" ]; then
222	cleanup
223	exit 0
224fi
225
226# We need access to CONFIG_ symbols
227. include/config/auto.conf
 
 
 
 
 
 
 
228
229# Update version
230info GEN .version
231if [ -r .version ]; then
232	VERSION=$(expr 0$(cat .version) + 1)
233	echo $VERSION > .version
234else
235	rm -f .version
236	echo 1 > .version
237fi;
238
239# final build of init/
240${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
241
 
 
242#link vmlinux.o
243info LD vmlinux.o
244modpost_link vmlinux.o
245
246# modpost vmlinux.o to check for section mismatches
247${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1
248
249info MODINFO modules.builtin.modinfo
250${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
251
252btf_vmlinux_bin_o=""
253if [ -n "${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
257fi
258
259kallsymso=""
260kallsymso_prev=""
261kallsyms_vmlinux=""
262if [ -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
297fi
298
299vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
 
300
301if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
302	info SORTEX vmlinux
303	sortextable vmlinux
304fi
305
306info SYSMAP System.map
307mksysmap vmlinux System.map
308
309# step a (see comment above)
310if [ -n "${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
318fi