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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# Link of vmlinux.o used for section mismatch analysis
41# ${1} output file
42modpost_link()
43{
44 ${LD} ${LDFLAGS} -r -o ${1} ${KBUILD_VMLINUX_INIT} \
45 --start-group ${KBUILD_VMLINUX_MAIN} --end-group
46}
47
48# Link of vmlinux
49# ${1} - optional extra .o files
50# ${2} - output file
51vmlinux_link()
52{
53 local lds="${objtree}/${KBUILD_LDS}"
54
55 if [ "${SRCARCH}" != "um" ]; then
56 ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
57 -T ${lds} ${KBUILD_VMLINUX_INIT} \
58 --start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1}
59 else
60 ${CC} ${CFLAGS_vmlinux} -o ${2} \
61 -Wl,-T,${lds} ${KBUILD_VMLINUX_INIT} \
62 -Wl,--start-group \
63 ${KBUILD_VMLINUX_MAIN} \
64 -Wl,--end-group \
65 -lutil -lrt -lpthread ${1}
66 rm -f linux
67 fi
68}
69
70
71# Create ${2} .o file with all symbols from the ${1} object file
72kallsyms()
73{
74 info KSYM ${2}
75 local kallsymopt;
76
77 if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
78 kallsymopt="${kallsymopt} --symbol-prefix=_"
79 fi
80
81 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
82 kallsymopt="${kallsymopt} --all-symbols"
83 fi
84
85 if [ -n "${CONFIG_ARM}" ] && [ -z "${CONFIG_XIP_KERNEL}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then
86 kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
87 fi
88
89 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
90 kallsymopt="${kallsymopt} --absolute-percpu"
91 fi
92
93 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
94 kallsymopt="${kallsymopt} --base-relative"
95 fi
96
97 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
98 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
99
100 local afile="`basename ${2} .o`.S"
101
102 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
103 ${CC} ${aflags} -c -o ${2} ${afile}
104}
105
106# Create map file with all symbols from ${1}
107# See mksymap for additional details
108mksysmap()
109{
110 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
111}
112
113sortextable()
114{
115 ${objtree}/scripts/sortextable ${1}
116}
117
118# Delete output files in case of error
119cleanup()
120{
121 rm -f .old_version
122 rm -f .tmp_System.map
123 rm -f .tmp_kallsyms*
124 rm -f .tmp_version
125 rm -f .tmp_vmlinux*
126 rm -f System.map
127 rm -f vmlinux
128 rm -f vmlinux.o
129}
130
131on_exit()
132{
133 if [ $? -ne 0 ]; then
134 cleanup
135 fi
136}
137trap on_exit EXIT
138
139on_signals()
140{
141 exit 1
142}
143trap on_signals HUP INT QUIT TERM
144
145#
146#
147# Use "make V=1" to debug this script
148case "${KBUILD_VERBOSE}" in
149*1*)
150 set -x
151 ;;
152esac
153
154if [ "$1" = "clean" ]; then
155 cleanup
156 exit 0
157fi
158
159# We need access to CONFIG_ symbols
160case "${KCONFIG_CONFIG}" in
161*/*)
162 . "${KCONFIG_CONFIG}"
163 ;;
164*)
165 # Force using a file from the current directory
166 . "./${KCONFIG_CONFIG}"
167esac
168
169#link vmlinux.o
170info LD vmlinux.o
171modpost_link vmlinux.o
172
173# modpost vmlinux.o to check for section mismatches
174${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
175
176# Update version
177info GEN .version
178if [ ! -r .version ]; then
179 rm -f .version;
180 echo 1 >.version;
181else
182 mv .version .old_version;
183 expr 0$(cat .old_version) + 1 >.version;
184fi;
185
186# final build of init/
187${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
188
189kallsymso=""
190kallsyms_vmlinux=""
191if [ -n "${CONFIG_KALLSYMS}" ]; then
192
193 # kallsyms support
194 # Generate section listing all symbols and add it into vmlinux
195 # It's a three step process:
196 # 1) Link .tmp_vmlinux1 so it has all symbols and sections,
197 # but __kallsyms is empty.
198 # Running kallsyms on that gives us .tmp_kallsyms1.o with
199 # the right size
200 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
201 # the right size, but due to the added section, some
202 # addresses have shifted.
203 # From here, we generate a correct .tmp_kallsyms2.o
204 # 2a) We may use an extra pass as this has been necessary to
205 # woraround some alignment related bugs.
206 # KALLSYMS_EXTRA_PASS=1 is used to trigger this.
207 # 3) The correct ${kallsymso} is linked into the final vmlinux.
208 #
209 # a) Verify that the System.map from vmlinux matches the map from
210 # ${kallsymso}.
211
212 kallsymso=.tmp_kallsyms2.o
213 kallsyms_vmlinux=.tmp_vmlinux2
214
215 # step 1
216 vmlinux_link "" .tmp_vmlinux1
217 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
218
219 # step 2
220 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
221 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
222
223 # step 2a
224 if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
225 kallsymso=.tmp_kallsyms3.o
226 kallsyms_vmlinux=.tmp_vmlinux3
227
228 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
229
230 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
231 fi
232fi
233
234info LD vmlinux
235vmlinux_link "${kallsymso}" vmlinux
236
237if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
238 info SORTEX vmlinux
239 sortextable vmlinux
240fi
241
242info SYSMAP System.map
243mksysmap vmlinux System.map
244
245# step a (see comment above)
246if [ -n "${CONFIG_KALLSYMS}" ]; then
247 mksysmap ${kallsyms_vmlinux} .tmp_System.map
248
249 if ! cmp -s System.map .tmp_System.map; then
250 echo >&2 Inconsistent kallsyms data
251 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
252 exit 1
253 fi
254fi
255
256# We made a new kernel - delete old version file
257rm -f .old_version
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
33LD="$1"
34KBUILD_LDFLAGS="$2"
35LDFLAGS_vmlinux="$3"
36
37# Nice output in kbuild format
38# Will be supressed by "make -s"
39info()
40{
41 if [ "${quiet}" != "silent_" ]; then
42 printf " %-7s %s\n" "${1}" "${2}"
43 fi
44}
45
46# Link of vmlinux.o used for section mismatch analysis
47# ${1} output file
48modpost_link()
49{
50 local objects
51
52 objects="--whole-archive \
53 ${KBUILD_VMLINUX_OBJS} \
54 --no-whole-archive \
55 --start-group \
56 ${KBUILD_VMLINUX_LIBS} \
57 --end-group"
58
59 ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects}
60}
61
62objtool_link()
63{
64 local objtoolopt;
65
66 if [ -n "${CONFIG_VMLINUX_VALIDATION}" ]; then
67 objtoolopt="check"
68 if [ -z "${CONFIG_FRAME_POINTER}" ]; then
69 objtoolopt="${objtoolopt} --no-fp"
70 fi
71 if [ -n "${CONFIG_GCOV_KERNEL}" ]; then
72 objtoolopt="${objtoolopt} --no-unreachable"
73 fi
74 if [ -n "${CONFIG_RETPOLINE}" ]; then
75 objtoolopt="${objtoolopt} --retpoline"
76 fi
77 if [ -n "${CONFIG_X86_SMAP}" ]; then
78 objtoolopt="${objtoolopt} --uaccess"
79 fi
80 info OBJTOOL ${1}
81 tools/objtool/objtool ${objtoolopt} ${1}
82 fi
83}
84
85# Link of vmlinux
86# ${1} - output file
87# ${2}, ${3}, ... - optional extra .o files
88vmlinux_link()
89{
90 local lds="${objtree}/${KBUILD_LDS}"
91 local output=${1}
92 local objects
93 local strip_debug
94
95 info LD ${output}
96
97 # skip output file argument
98 shift
99
100 # The kallsyms linking does not need debug symbols included.
101 if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
102 strip_debug=-Wl,--strip-debug
103 fi
104
105 if [ "${SRCARCH}" != "um" ]; then
106 objects="--whole-archive \
107 ${KBUILD_VMLINUX_OBJS} \
108 --no-whole-archive \
109 --start-group \
110 ${KBUILD_VMLINUX_LIBS} \
111 --end-group \
112 ${@}"
113
114 ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
115 ${strip_debug#-Wl,} \
116 -o ${output} \
117 -T ${lds} ${objects}
118 else
119 objects="-Wl,--whole-archive \
120 ${KBUILD_VMLINUX_OBJS} \
121 -Wl,--no-whole-archive \
122 -Wl,--start-group \
123 ${KBUILD_VMLINUX_LIBS} \
124 -Wl,--end-group \
125 ${@}"
126
127 ${CC} ${CFLAGS_vmlinux} \
128 ${strip_debug} \
129 -o ${output} \
130 -Wl,-T,${lds} \
131 ${objects} \
132 -lutil -lrt -lpthread
133 rm -f linux
134 fi
135}
136
137# generate .BTF typeinfo from DWARF debuginfo
138# ${1} - vmlinux image
139# ${2} - file to dump raw BTF data into
140gen_btf()
141{
142 local pahole_ver
143
144 if ! [ -x "$(command -v ${PAHOLE})" ]; then
145 echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
146 return 1
147 fi
148
149 pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
150 if [ "${pahole_ver}" -lt "116" ]; then
151 echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16"
152 return 1
153 fi
154
155 vmlinux_link ${1}
156
157 info "BTF" ${2}
158 LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
159
160 # Create ${2} which contains just .BTF section but no symbols. Add
161 # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
162 # deletes all symbols including __start_BTF and __stop_BTF, which will
163 # be redefined in the linker script. Add 2>/dev/null to suppress GNU
164 # objcopy warnings: "empty loadable segment detected at ..."
165 ${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
166 --strip-all ${1} ${2} 2>/dev/null
167 # Change e_type to ET_REL so that it can be used to link final vmlinux.
168 # Unlike GNU ld, lld does not allow an ET_EXEC input.
169 printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
170}
171
172# Create ${2} .o file with all symbols from the ${1} object file
173kallsyms()
174{
175 info KSYM ${2}
176 local kallsymopt;
177
178 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
179 kallsymopt="${kallsymopt} --all-symbols"
180 fi
181
182 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
183 kallsymopt="${kallsymopt} --absolute-percpu"
184 fi
185
186 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
187 kallsymopt="${kallsymopt} --base-relative"
188 fi
189
190 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
191 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
192
193 local afile="`basename ${2} .o`.S"
194
195 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
196 ${CC} ${aflags} -c -o ${2} ${afile}
197}
198
199# Perform one step in kallsyms generation, including temporary linking of
200# vmlinux.
201kallsyms_step()
202{
203 kallsymso_prev=${kallsymso}
204 kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
205 kallsymso=${kallsyms_vmlinux}.o
206
207 vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
208 kallsyms ${kallsyms_vmlinux} ${kallsymso}
209}
210
211# Create map file with all symbols from ${1}
212# See mksymap for additional details
213mksysmap()
214{
215 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
216}
217
218sorttable()
219{
220 ${objtree}/scripts/sorttable ${1}
221}
222
223# Delete output files in case of error
224cleanup()
225{
226 rm -f .btf.*
227 rm -f .tmp_System.map
228 rm -f .tmp_vmlinux*
229 rm -f System.map
230 rm -f vmlinux
231 rm -f vmlinux.o
232}
233
234on_exit()
235{
236 if [ $? -ne 0 ]; then
237 cleanup
238 fi
239}
240trap on_exit EXIT
241
242on_signals()
243{
244 exit 1
245}
246trap on_signals HUP INT QUIT TERM
247
248# Use "make V=1" to debug this script
249case "${KBUILD_VERBOSE}" in
250*1*)
251 set -x
252 ;;
253esac
254
255if [ "$1" = "clean" ]; then
256 cleanup
257 exit 0
258fi
259
260# We need access to CONFIG_ symbols
261. include/config/auto.conf
262
263# Update version
264info GEN .version
265if [ -r .version ]; then
266 VERSION=$(expr 0$(cat .version) + 1)
267 echo $VERSION > .version
268else
269 rm -f .version
270 echo 1 > .version
271fi;
272
273# final build of init/
274${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
275
276#link vmlinux.o
277info LD vmlinux.o
278modpost_link vmlinux.o
279objtool_link vmlinux.o
280
281# modpost vmlinux.o to check for section mismatches
282${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1
283
284info MODINFO modules.builtin.modinfo
285${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
286info GEN modules.builtin
287# The second line aids cases where multiple modules share the same object.
288tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' |
289 tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin
290
291btf_vmlinux_bin_o=""
292if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
293 btf_vmlinux_bin_o=.btf.vmlinux.bin.o
294 if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then
295 echo >&2 "Failed to generate BTF for vmlinux"
296 echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
297 exit 1
298 fi
299fi
300
301kallsymso=""
302kallsymso_prev=""
303kallsyms_vmlinux=""
304if [ -n "${CONFIG_KALLSYMS}" ]; then
305
306 # kallsyms support
307 # Generate section listing all symbols and add it into vmlinux
308 # It's a three step process:
309 # 1) Link .tmp_vmlinux1 so it has all symbols and sections,
310 # but __kallsyms is empty.
311 # Running kallsyms on that gives us .tmp_kallsyms1.o with
312 # the right size
313 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
314 # the right size, but due to the added section, some
315 # addresses have shifted.
316 # From here, we generate a correct .tmp_kallsyms2.o
317 # 3) That link may have expanded the kernel image enough that
318 # more linker branch stubs / trampolines had to be added, which
319 # introduces new names, which further expands kallsyms. Do another
320 # pass if that is the case. In theory it's possible this results
321 # in even more stubs, but unlikely.
322 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
323 # other bugs.
324 # 4) The correct ${kallsymso} is linked into the final vmlinux.
325 #
326 # a) Verify that the System.map from vmlinux matches the map from
327 # ${kallsymso}.
328
329 kallsyms_step 1
330 kallsyms_step 2
331
332 # step 3
333 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
334 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
335
336 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
337 kallsyms_step 3
338 fi
339fi
340
341vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
342
343# fill in BTF IDs
344if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
345info BTFIDS vmlinux
346${RESOLVE_BTFIDS} vmlinux
347fi
348
349if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
350 info SORTTAB vmlinux
351 if ! sorttable vmlinux; then
352 echo >&2 Failed to sort kernel tables
353 exit 1
354 fi
355fi
356
357info SYSMAP System.map
358mksysmap vmlinux System.map
359
360# step a (see comment above)
361if [ -n "${CONFIG_KALLSYMS}" ]; then
362 mksysmap ${kallsyms_vmlinux} .tmp_System.map
363
364 if ! cmp -s System.map .tmp_System.map; then
365 echo >&2 Inconsistent kallsyms data
366 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
367 exit 1
368 fi
369fi