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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
1#!/bin/sh
2#
3# link vmlinux
4#
5# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
6# $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories
7# in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
8# Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first.
9#
10# vmlinux
11# ^
12# |
13# +-< $(KBUILD_VMLINUX_INIT)
14# | +--< init/version.o + more
15# |
16# +--< $(KBUILD_VMLINUX_MAIN)
17# | +--< drivers/built-in.o mm/built-in.o + more
18# |
19# +-< ${kallsymso} (see description in KALLSYMS section)
20#
21# vmlinux version (uname -v) cannot be updated during normal
22# descending-into-subdirs phase since we do not yet know if we need to
23# update vmlinux.
24# Therefore this step is delayed until just before final link of vmlinux.
25#
26# System.map is generated to document addresses of all kernel symbols
27
28# Error out on error
29set -e
30
31# Nice output in kbuild format
32# Will be supressed by "make -s"
33info()
34{
35 if [ "${quiet}" != "silent_" ]; then
36 printf " %-7s %s\n" ${1} ${2}
37 fi
38}
39
40# Thin archive build here makes a final archive with
41# symbol table and indexes from vmlinux objects, which can be
42# used as input to linker.
43#
44# Traditional incremental style of link does not require this step
45#
46# built-in.o output file
47#
48archive_builtin()
49{
50 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
51 info AR built-in.o
52 rm -f built-in.o;
53 ${AR} rcsT${KBUILD_ARFLAGS} built-in.o \
54 ${KBUILD_VMLINUX_INIT} \
55 ${KBUILD_VMLINUX_MAIN}
56 fi
57}
58
59# Link of vmlinux.o used for section mismatch analysis
60# ${1} output file
61modpost_link()
62{
63 local objects
64
65 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
66 objects="--whole-archive built-in.o"
67 else
68 objects="${KBUILD_VMLINUX_INIT} \
69 --start-group \
70 ${KBUILD_VMLINUX_MAIN} \
71 --end-group"
72 fi
73 ${LD} ${LDFLAGS} -r -o ${1} ${objects}
74}
75
76# Link of vmlinux
77# ${1} - optional extra .o files
78# ${2} - output file
79vmlinux_link()
80{
81 local lds="${objtree}/${KBUILD_LDS}"
82 local objects
83
84 if [ "${SRCARCH}" != "um" ]; then
85 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
86 objects="--whole-archive built-in.o ${1}"
87 else
88 objects="${KBUILD_VMLINUX_INIT} \
89 --start-group \
90 ${KBUILD_VMLINUX_MAIN} \
91 --end-group \
92 ${1}"
93 fi
94
95 ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
96 -T ${lds} ${objects}
97 else
98 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
99 objects="-Wl,--whole-archive built-in.o ${1}"
100 else
101 objects="${KBUILD_VMLINUX_INIT} \
102 -Wl,--start-group \
103 ${KBUILD_VMLINUX_MAIN} \
104 -Wl,--end-group \
105 ${1}"
106 fi
107
108 ${CC} ${CFLAGS_vmlinux} -o ${2} \
109 -Wl,-T,${lds} \
110 ${objects} \
111 -lutil -lrt -lpthread
112 rm -f linux
113 fi
114}
115
116
117# Create ${2} .o file with all symbols from the ${1} object file
118kallsyms()
119{
120 info KSYM ${2}
121 local kallsymopt;
122
123 if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
124 kallsymopt="${kallsymopt} --symbol-prefix=_"
125 fi
126
127 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
128 kallsymopt="${kallsymopt} --all-symbols"
129 fi
130
131 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
132 kallsymopt="${kallsymopt} --absolute-percpu"
133 fi
134
135 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
136 kallsymopt="${kallsymopt} --base-relative"
137 fi
138
139 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
140 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
141
142 local afile="`basename ${2} .o`.S"
143
144 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
145 ${CC} ${aflags} -c -o ${2} ${afile}
146}
147
148# Create map file with all symbols from ${1}
149# See mksymap for additional details
150mksysmap()
151{
152 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
153}
154
155sortextable()
156{
157 ${objtree}/scripts/sortextable ${1}
158}
159
160# Delete output files in case of error
161cleanup()
162{
163 rm -f .old_version
164 rm -f .tmp_System.map
165 rm -f .tmp_kallsyms*
166 rm -f .tmp_version
167 rm -f .tmp_vmlinux*
168 rm -f built-in.o
169 rm -f System.map
170 rm -f vmlinux
171 rm -f vmlinux.o
172}
173
174on_exit()
175{
176 if [ $? -ne 0 ]; then
177 cleanup
178 fi
179}
180trap on_exit EXIT
181
182on_signals()
183{
184 exit 1
185}
186trap on_signals HUP INT QUIT TERM
187
188#
189#
190# Use "make V=1" to debug this script
191case "${KBUILD_VERBOSE}" in
192*1*)
193 set -x
194 ;;
195esac
196
197if [ "$1" = "clean" ]; then
198 cleanup
199 exit 0
200fi
201
202# We need access to CONFIG_ symbols
203case "${KCONFIG_CONFIG}" in
204*/*)
205 . "${KCONFIG_CONFIG}"
206 ;;
207*)
208 # Force using a file from the current directory
209 . "./${KCONFIG_CONFIG}"
210esac
211
212# Update version
213info GEN .version
214if [ ! -r .version ]; then
215 rm -f .version;
216 echo 1 >.version;
217else
218 mv .version .old_version;
219 expr 0$(cat .old_version) + 1 >.version;
220fi;
221
222# final build of init/
223${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
224
225archive_builtin
226
227#link vmlinux.o
228info LD vmlinux.o
229modpost_link vmlinux.o
230
231# modpost vmlinux.o to check for section mismatches
232${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
233
234kallsymso=""
235kallsyms_vmlinux=""
236if [ -n "${CONFIG_KALLSYMS}" ]; then
237
238 # kallsyms support
239 # Generate section listing all symbols and add it into vmlinux
240 # It's a three step process:
241 # 1) Link .tmp_vmlinux1 so it has all symbols and sections,
242 # but __kallsyms is empty.
243 # Running kallsyms on that gives us .tmp_kallsyms1.o with
244 # the right size
245 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
246 # the right size, but due to the added section, some
247 # addresses have shifted.
248 # From here, we generate a correct .tmp_kallsyms2.o
249 # 3) That link may have expanded the kernel image enough that
250 # more linker branch stubs / trampolines had to be added, which
251 # introduces new names, which further expands kallsyms. Do another
252 # pass if that is the case. In theory it's possible this results
253 # in even more stubs, but unlikely.
254 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
255 # other bugs.
256 # 4) The correct ${kallsymso} is linked into the final vmlinux.
257 #
258 # a) Verify that the System.map from vmlinux matches the map from
259 # ${kallsymso}.
260
261 kallsymso=.tmp_kallsyms2.o
262 kallsyms_vmlinux=.tmp_vmlinux2
263
264 # step 1
265 vmlinux_link "" .tmp_vmlinux1
266 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
267
268 # step 2
269 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
270 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
271
272 # step 3
273 size1=$(stat -c "%s" .tmp_kallsyms1.o)
274 size2=$(stat -c "%s" .tmp_kallsyms2.o)
275
276 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
277 kallsymso=.tmp_kallsyms3.o
278 kallsyms_vmlinux=.tmp_vmlinux3
279
280 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
281
282 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
283 fi
284fi
285
286info LD vmlinux
287vmlinux_link "${kallsymso}" vmlinux
288
289if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
290 info SORTEX vmlinux
291 sortextable vmlinux
292fi
293
294info SYSMAP System.map
295mksysmap vmlinux System.map
296
297# step a (see comment above)
298if [ -n "${CONFIG_KALLSYMS}" ]; then
299 mksysmap ${kallsyms_vmlinux} .tmp_System.map
300
301 if ! cmp -s System.map .tmp_System.map; then
302 echo >&2 Inconsistent kallsyms data
303 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
304 exit 1
305 fi
306fi
307
308# We made a new kernel - delete old version file
309rm -f .old_version