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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 in vmlinux.a and $(KBUILD_VMLINUX_LIBS).
7# vmlinux.a contains objects that are linked unconditionally.
8# $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
9# (not within --whole-archive), and do not require symbol indexes added.
10#
11# vmlinux
12# ^
13# |
14# +--< vmlinux.a
15# |
16# +--< $(KBUILD_VMLINUX_LIBS)
17# | +--< lib/lib.a + 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
31LD="$1"
32KBUILD_LDFLAGS="$2"
33LDFLAGS_vmlinux="$3"
34
35is_enabled() {
36 grep -q "^$1=y" include/config/auto.conf
37}
38
39# Nice output in kbuild format
40# Will be supressed by "make -s"
41info()
42{
43 printf " %-7s %s\n" "${1}" "${2}"
44}
45
46# Link of vmlinux
47# ${1} - output file
48# ${2}, ${3}, ... - optional extra .o files
49vmlinux_link()
50{
51 local output=${1}
52 local objs
53 local libs
54 local ld
55 local ldflags
56 local ldlibs
57
58 info LD ${output}
59
60 # skip output file argument
61 shift
62
63 if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
64 # Use vmlinux.o instead of performing the slow LTO link again.
65 objs=vmlinux.o
66 libs=
67 else
68 objs=vmlinux.a
69 libs="${KBUILD_VMLINUX_LIBS}"
70 fi
71
72 if is_enabled CONFIG_MODULES; then
73 objs="${objs} .vmlinux.export.o"
74 fi
75
76 objs="${objs} init/version-timestamp.o"
77
78 if [ "${SRCARCH}" = "um" ]; then
79 wl=-Wl,
80 ld="${CC}"
81 ldflags="${CFLAGS_vmlinux}"
82 ldlibs="-lutil -lrt -lpthread"
83 else
84 wl=
85 ld="${LD}"
86 ldflags="${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux}"
87 ldlibs=
88 fi
89
90 ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}"
91
92 # The kallsyms linking does not need debug symbols included.
93 if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
94 ldflags="${ldflags} ${wl}--strip-debug"
95 fi
96
97 if is_enabled CONFIG_VMLINUX_MAP; then
98 ldflags="${ldflags} ${wl}-Map=${output}.map"
99 fi
100
101 ${ld} ${ldflags} -o ${output} \
102 ${wl}--whole-archive ${objs} ${wl}--no-whole-archive \
103 ${wl}--start-group ${libs} ${wl}--end-group \
104 $@ ${ldlibs}
105}
106
107# generate .BTF typeinfo from DWARF debuginfo
108# ${1} - vmlinux image
109# ${2} - file to dump raw BTF data into
110gen_btf()
111{
112 local pahole_ver
113
114 if ! [ -x "$(command -v ${PAHOLE})" ]; then
115 echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
116 return 1
117 fi
118
119 pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
120 if [ "${pahole_ver}" -lt "116" ]; then
121 echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16"
122 return 1
123 fi
124
125 vmlinux_link ${1}
126
127 info "BTF" ${2}
128 LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
129
130 # Create ${2} which contains just .BTF section but no symbols. Add
131 # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
132 # deletes all symbols including __start_BTF and __stop_BTF, which will
133 # be redefined in the linker script. Add 2>/dev/null to suppress GNU
134 # objcopy warnings: "empty loadable segment detected at ..."
135 ${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
136 --strip-all ${1} ${2} 2>/dev/null
137 # Change e_type to ET_REL so that it can be used to link final vmlinux.
138 # GNU ld 2.35+ and lld do not allow an ET_EXEC input.
139 if is_enabled CONFIG_CPU_BIG_ENDIAN; then
140 et_rel='\0\1'
141 else
142 et_rel='\1\0'
143 fi
144 printf "${et_rel}" | dd of=${2} conv=notrunc bs=1 seek=16 status=none
145}
146
147# Create ${2} .S file with all symbols from the ${1} object file
148kallsyms()
149{
150 local kallsymopt;
151
152 if is_enabled CONFIG_KALLSYMS_ALL; then
153 kallsymopt="${kallsymopt} --all-symbols"
154 fi
155
156 if is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU; then
157 kallsymopt="${kallsymopt} --absolute-percpu"
158 fi
159
160 if is_enabled CONFIG_KALLSYMS_BASE_RELATIVE; then
161 kallsymopt="${kallsymopt} --base-relative"
162 fi
163
164 if is_enabled CONFIG_LTO_CLANG; then
165 kallsymopt="${kallsymopt} --lto-clang"
166 fi
167
168 info KSYMS ${2}
169 scripts/kallsyms ${kallsymopt} ${1} > ${2}
170}
171
172# Perform one step in kallsyms generation, including temporary linking of
173# vmlinux.
174kallsyms_step()
175{
176 kallsymso_prev=${kallsymso}
177 kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
178 kallsymso=${kallsyms_vmlinux}.o
179 kallsyms_S=${kallsyms_vmlinux}.S
180
181 vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
182 mksysmap ${kallsyms_vmlinux} ${kallsyms_vmlinux}.syms ${kallsymso_prev}
183 kallsyms ${kallsyms_vmlinux}.syms ${kallsyms_S}
184
185 info AS ${kallsyms_S}
186 ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
187 ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
188 -c -o ${kallsymso} ${kallsyms_S}
189}
190
191# Create map file with all symbols from ${1}
192# See mksymap for additional details
193mksysmap()
194{
195 info NM ${2}
196 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} ${3}
197}
198
199sorttable()
200{
201 ${objtree}/scripts/sorttable ${1}
202}
203
204# Delete output files in case of error
205cleanup()
206{
207 rm -f .btf.*
208 rm -f System.map
209 rm -f vmlinux
210 rm -f vmlinux.map
211}
212
213# Use "make V=1" to debug this script
214case "${KBUILD_VERBOSE}" in
215*1*)
216 set -x
217 ;;
218esac
219
220if [ "$1" = "clean" ]; then
221 cleanup
222 exit 0
223fi
224
225${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init init/version-timestamp.o
226
227btf_vmlinux_bin_o=""
228if is_enabled CONFIG_DEBUG_INFO_BTF; then
229 btf_vmlinux_bin_o=.btf.vmlinux.bin.o
230 if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then
231 echo >&2 "Failed to generate BTF for vmlinux"
232 echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
233 exit 1
234 fi
235fi
236
237kallsymso=""
238kallsymso_prev=""
239kallsyms_vmlinux=""
240if is_enabled CONFIG_KALLSYMS; then
241
242 # kallsyms support
243 # Generate section listing all symbols and add it into vmlinux
244 # It's a three step process:
245 # 1) Link .tmp_vmlinux.kallsyms1 so it has all symbols and sections,
246 # but __kallsyms is empty.
247 # Running kallsyms on that gives us .tmp_kallsyms1.o with
248 # the right size
249 # 2) Link .tmp_vmlinux.kallsyms2 so it now has a __kallsyms section of
250 # the right size, but due to the added section, some
251 # addresses have shifted.
252 # From here, we generate a correct .tmp_vmlinux.kallsyms2.o
253 # 3) That link may have expanded the kernel image enough that
254 # more linker branch stubs / trampolines had to be added, which
255 # introduces new names, which further expands kallsyms. Do another
256 # pass if that is the case. In theory it's possible this results
257 # in even more stubs, but unlikely.
258 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
259 # other bugs.
260 # 4) The correct ${kallsymso} is linked into the final vmlinux.
261 #
262 # a) Verify that the System.map from vmlinux matches the map from
263 # ${kallsymso}.
264
265 kallsyms_step 1
266 kallsyms_step 2
267
268 # step 3
269 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
270 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
271
272 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
273 kallsyms_step 3
274 fi
275fi
276
277vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
278
279# fill in BTF IDs
280if is_enabled CONFIG_DEBUG_INFO_BTF && is_enabled CONFIG_BPF; then
281 info BTFIDS vmlinux
282 ${RESOLVE_BTFIDS} vmlinux
283fi
284
285mksysmap vmlinux System.map ${kallsymso}
286
287if is_enabled CONFIG_BUILDTIME_TABLE_SORT; then
288 info SORTTAB vmlinux
289 if ! sorttable vmlinux; then
290 echo >&2 Failed to sort kernel tables
291 exit 1
292 fi
293fi
294
295# step a (see comment above)
296if is_enabled CONFIG_KALLSYMS; then
297 if ! cmp -s System.map ${kallsyms_vmlinux}.syms; then
298 echo >&2 Inconsistent kallsyms data
299 echo >&2 'Try "make KALLSYMS_EXTRA_PASS=1" as a workaround'
300 exit 1
301 fi
302fi
303
304# For fixdep
305echo "vmlinux: $0" > .vmlinux.d
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="$3"
36
37# Nice output in kbuild format
38# Will be supressed by "make -s"
39info()
40{
41 printf " %-7s %s\n" "${1}" "${2}"
42}
43
44# Generate a linker script to ensure correct ordering of initcalls.
45gen_initcalls()
46{
47 info GEN .tmp_initcalls.lds
48
49 ${PYTHON} ${srctree}/scripts/jobserver-exec \
50 ${PERL} ${srctree}/scripts/generate_initcall_order.pl \
51 ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS} \
52 > .tmp_initcalls.lds
53}
54
55# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into
56# .tmp_symversions.lds
57gen_symversions()
58{
59 info GEN .tmp_symversions.lds
60 rm -f .tmp_symversions.lds
61
62 for o in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do
63 if [ -f ${o}.symversions ]; then
64 cat ${o}.symversions >> .tmp_symversions.lds
65 fi
66 done
67}
68
69# Link of vmlinux.o used for section mismatch analysis
70# ${1} output file
71modpost_link()
72{
73 local objects
74 local lds=""
75
76 objects="--whole-archive \
77 ${KBUILD_VMLINUX_OBJS} \
78 --no-whole-archive \
79 --start-group \
80 ${KBUILD_VMLINUX_LIBS} \
81 --end-group"
82
83 if [ -n "${CONFIG_LTO_CLANG}" ]; then
84 gen_initcalls
85 lds="-T .tmp_initcalls.lds"
86
87 if [ -n "${CONFIG_MODVERSIONS}" ]; then
88 gen_symversions
89 lds="${lds} -T .tmp_symversions.lds"
90 fi
91
92 # This might take a while, so indicate that we're doing
93 # an LTO link
94 info LTO ${1}
95 else
96 info LD ${1}
97 fi
98
99 ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${lds} ${objects}
100}
101
102objtool_link()
103{
104 local objtoolcmd;
105 local objtoolopt;
106
107 if [ "${CONFIG_LTO_CLANG} ${CONFIG_STACK_VALIDATION}" = "y y" ]; then
108 # Don't perform vmlinux validation unless explicitly requested,
109 # but run objtool on vmlinux.o now that we have an object file.
110 if [ -n "${CONFIG_UNWINDER_ORC}" ]; then
111 objtoolcmd="orc generate"
112 fi
113
114 objtoolopt="${objtoolopt} --duplicate"
115
116 if [ -n "${CONFIG_FTRACE_MCOUNT_USE_OBJTOOL}" ]; then
117 objtoolopt="${objtoolopt} --mcount"
118 fi
119 fi
120
121 if [ -n "${CONFIG_VMLINUX_VALIDATION}" ]; then
122 objtoolopt="${objtoolopt} --noinstr"
123 fi
124
125 if [ -n "${objtoolopt}" ]; then
126 if [ -z "${objtoolcmd}" ]; then
127 objtoolcmd="check"
128 fi
129 objtoolopt="${objtoolopt} --vmlinux"
130 if [ -z "${CONFIG_FRAME_POINTER}" ]; then
131 objtoolopt="${objtoolopt} --no-fp"
132 fi
133 if [ -n "${CONFIG_GCOV_KERNEL}" ] || [ -n "${CONFIG_LTO_CLANG}" ]; then
134 objtoolopt="${objtoolopt} --no-unreachable"
135 fi
136 if [ -n "${CONFIG_RETPOLINE}" ]; then
137 objtoolopt="${objtoolopt} --retpoline"
138 fi
139 if [ -n "${CONFIG_X86_SMAP}" ]; then
140 objtoolopt="${objtoolopt} --uaccess"
141 fi
142 info OBJTOOL ${1}
143 tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1}
144 fi
145}
146
147# Link of vmlinux
148# ${1} - output file
149# ${2}, ${3}, ... - optional extra .o files
150vmlinux_link()
151{
152 local lds="${objtree}/${KBUILD_LDS}"
153 local output=${1}
154 local objects
155 local strip_debug
156 local map_option
157
158 info LD ${output}
159
160 # skip output file argument
161 shift
162
163 # The kallsyms linking does not need debug symbols included.
164 if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
165 strip_debug=-Wl,--strip-debug
166 fi
167
168 if [ -n "${CONFIG_VMLINUX_MAP}" ]; then
169 map_option="-Map=${output}.map"
170 fi
171
172 if [ "${SRCARCH}" != "um" ]; then
173 if [ -n "${CONFIG_LTO_CLANG}" ]; then
174 # Use vmlinux.o instead of performing the slow LTO
175 # link again.
176 objects="--whole-archive \
177 vmlinux.o \
178 --no-whole-archive \
179 ${@}"
180 else
181 objects="--whole-archive \
182 ${KBUILD_VMLINUX_OBJS} \
183 --no-whole-archive \
184 --start-group \
185 ${KBUILD_VMLINUX_LIBS} \
186 --end-group \
187 ${@}"
188 fi
189
190 ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
191 ${strip_debug#-Wl,} \
192 -o ${output} \
193 ${map_option} \
194 -T ${lds} ${objects}
195 else
196 objects="-Wl,--whole-archive \
197 ${KBUILD_VMLINUX_OBJS} \
198 -Wl,--no-whole-archive \
199 -Wl,--start-group \
200 ${KBUILD_VMLINUX_LIBS} \
201 -Wl,--end-group \
202 ${@}"
203
204 ${CC} ${CFLAGS_vmlinux} \
205 ${strip_debug} \
206 -o ${output} \
207 ${map_option:+-Wl,${map_option}} \
208 -Wl,-T,${lds} \
209 ${objects} \
210 -lutil -lrt -lpthread
211 rm -f linux
212 fi
213}
214
215# generate .BTF typeinfo from DWARF debuginfo
216# ${1} - vmlinux image
217# ${2} - file to dump raw BTF data into
218gen_btf()
219{
220 local pahole_ver
221 local extra_paholeopt=
222
223 if ! [ -x "$(command -v ${PAHOLE})" ]; then
224 echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
225 return 1
226 fi
227
228 pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
229 if [ "${pahole_ver}" -lt "116" ]; then
230 echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16"
231 return 1
232 fi
233
234 vmlinux_link ${1}
235
236 if [ "${pahole_ver}" -ge "118" ] && [ "${pahole_ver}" -le "121" ]; then
237 # pahole 1.18 through 1.21 can't handle zero-sized per-CPU vars
238 extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_vars"
239 fi
240 if [ "${pahole_ver}" -ge "121" ]; then
241 extra_paholeopt="${extra_paholeopt} --btf_gen_floats"
242 fi
243
244 info "BTF" ${2}
245 LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${extra_paholeopt} ${1}
246
247 # Create ${2} which contains just .BTF section but no symbols. Add
248 # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
249 # deletes all symbols including __start_BTF and __stop_BTF, which will
250 # be redefined in the linker script. Add 2>/dev/null to suppress GNU
251 # objcopy warnings: "empty loadable segment detected at ..."
252 ${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
253 --strip-all ${1} ${2} 2>/dev/null
254 # Change e_type to ET_REL so that it can be used to link final vmlinux.
255 # Unlike GNU ld, lld does not allow an ET_EXEC input.
256 printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
257}
258
259# Create ${2} .S file with all symbols from the ${1} object file
260kallsyms()
261{
262 local kallsymopt;
263
264 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
265 kallsymopt="${kallsymopt} --all-symbols"
266 fi
267
268 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
269 kallsymopt="${kallsymopt} --absolute-percpu"
270 fi
271
272 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
273 kallsymopt="${kallsymopt} --base-relative"
274 fi
275
276 info KSYMS ${2}
277 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${2}
278}
279
280# Perform one step in kallsyms generation, including temporary linking of
281# vmlinux.
282kallsyms_step()
283{
284 kallsymso_prev=${kallsymso}
285 kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
286 kallsymso=${kallsyms_vmlinux}.o
287 kallsyms_S=${kallsyms_vmlinux}.S
288
289 vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
290 kallsyms ${kallsyms_vmlinux} ${kallsyms_S}
291
292 info AS ${kallsyms_S}
293 ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
294 ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
295 -c -o ${kallsymso} ${kallsyms_S}
296}
297
298# Create map file with all symbols from ${1}
299# See mksymap for additional details
300mksysmap()
301{
302 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
303}
304
305sorttable()
306{
307 ${objtree}/scripts/sorttable ${1}
308}
309
310# Delete output files in case of error
311cleanup()
312{
313 rm -f .btf.*
314 rm -f .tmp_System.map
315 rm -f .tmp_initcalls.lds
316 rm -f .tmp_symversions.lds
317 rm -f .tmp_vmlinux*
318 rm -f System.map
319 rm -f vmlinux
320 rm -f vmlinux.map
321 rm -f vmlinux.o
322 rm -f .vmlinux.d
323}
324
325# Use "make V=1" to debug this script
326case "${KBUILD_VERBOSE}" in
327*1*)
328 set -x
329 ;;
330esac
331
332if [ "$1" = "clean" ]; then
333 cleanup
334 exit 0
335fi
336
337# We need access to CONFIG_ symbols
338. include/config/auto.conf
339
340# Update version
341info GEN .version
342if [ -r .version ]; then
343 VERSION=$(expr 0$(cat .version) + 1)
344 echo $VERSION > .version
345else
346 rm -f .version
347 echo 1 > .version
348fi;
349
350# final build of init/
351${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
352
353#link vmlinux.o
354modpost_link vmlinux.o
355objtool_link vmlinux.o
356
357# modpost vmlinux.o to check for section mismatches
358${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1
359
360info MODINFO modules.builtin.modinfo
361${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
362info GEN modules.builtin
363# The second line aids cases where multiple modules share the same object.
364tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' |
365 tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin
366
367btf_vmlinux_bin_o=""
368if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
369 btf_vmlinux_bin_o=.btf.vmlinux.bin.o
370 if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then
371 echo >&2 "Failed to generate BTF for vmlinux"
372 echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
373 exit 1
374 fi
375fi
376
377kallsymso=""
378kallsymso_prev=""
379kallsyms_vmlinux=""
380if [ -n "${CONFIG_KALLSYMS}" ]; then
381
382 # kallsyms support
383 # Generate section listing all symbols and add it into vmlinux
384 # It's a three step process:
385 # 1) Link .tmp_vmlinux1 so it has all symbols and sections,
386 # but __kallsyms is empty.
387 # Running kallsyms on that gives us .tmp_kallsyms1.o with
388 # the right size
389 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
390 # the right size, but due to the added section, some
391 # addresses have shifted.
392 # From here, we generate a correct .tmp_kallsyms2.o
393 # 3) That link may have expanded the kernel image enough that
394 # more linker branch stubs / trampolines had to be added, which
395 # introduces new names, which further expands kallsyms. Do another
396 # pass if that is the case. In theory it's possible this results
397 # in even more stubs, but unlikely.
398 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
399 # other bugs.
400 # 4) The correct ${kallsymso} is linked into the final vmlinux.
401 #
402 # a) Verify that the System.map from vmlinux matches the map from
403 # ${kallsymso}.
404
405 kallsyms_step 1
406 kallsyms_step 2
407
408 # step 3
409 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
410 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
411
412 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
413 kallsyms_step 3
414 fi
415fi
416
417vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
418
419# fill in BTF IDs
420if [ -n "${CONFIG_DEBUG_INFO_BTF}" -a -n "${CONFIG_BPF}" ]; then
421 info BTFIDS vmlinux
422 ${RESOLVE_BTFIDS} vmlinux
423fi
424
425if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
426 info SORTTAB vmlinux
427 if ! sorttable vmlinux; then
428 echo >&2 Failed to sort kernel tables
429 exit 1
430 fi
431fi
432
433info SYSMAP System.map
434mksysmap vmlinux System.map
435
436# step a (see comment above)
437if [ -n "${CONFIG_KALLSYMS}" ]; then
438 mksysmap ${kallsyms_vmlinux} .tmp_System.map
439
440 if ! cmp -s System.map .tmp_System.map; then
441 echo >&2 Inconsistent kallsyms data
442 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
443 exit 1
444 fi
445fi
446
447# For fixdep
448echo "vmlinux: $0" > .vmlinux.d