1 #!/bin/sh 1 #!/bin/sh
2 # SPDX-License-Identifier: GPL-2.0 2 # SPDX-License-Identifier: GPL-2.0
3 # 3 #
4 # link vmlinux 4 # link vmlinux
5 # 5 #
6 # vmlinux is linked from the objects in vmlinu !! 6 # vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_OBJS) and
7 # vmlinux.a contains objects that are linked u !! 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.
8 # $(KBUILD_VMLINUX_LIBS) are archives which ar 9 # $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
9 # (not within --whole-archive), and do not req 10 # (not within --whole-archive), and do not require symbol indexes added.
10 # 11 #
11 # vmlinux 12 # vmlinux
12 # ^ 13 # ^
13 # | 14 # |
14 # +--< vmlinux.a !! 15 # +--< $(KBUILD_VMLINUX_OBJS)
>> 16 # | +--< init/built-in.a drivers/built-in.a mm/built-in.a + more
15 # | 17 # |
16 # +--< $(KBUILD_VMLINUX_LIBS) 18 # +--< $(KBUILD_VMLINUX_LIBS)
17 # | +--< lib/lib.a + more 19 # | +--< lib/lib.a + more
18 # | 20 # |
19 # +-< ${kallsymso} (see description in KALLS 21 # +-< ${kallsymso} (see description in KALLSYMS section)
20 # 22 #
21 # vmlinux version (uname -v) cannot be updated 23 # vmlinux version (uname -v) cannot be updated during normal
22 # descending-into-subdirs phase since we do no 24 # descending-into-subdirs phase since we do not yet know if we need to
23 # update vmlinux. 25 # update vmlinux.
24 # Therefore this step is delayed until just be 26 # Therefore this step is delayed until just before final link of vmlinux.
25 # 27 #
26 # System.map is generated to document addresse 28 # System.map is generated to document addresses of all kernel symbols
27 29
28 # Error out on error 30 # Error out on error
29 set -e 31 set -e
30 32
31 LD="$1" <<
32 KBUILD_LDFLAGS="$2" <<
33 LDFLAGS_vmlinux="$3" <<
34 <<
35 is_enabled() { <<
36 grep -q "^$1=y" include/config/auto.co <<
37 } <<
38 <<
39 # Nice output in kbuild format 33 # Nice output in kbuild format
40 # Will be supressed by "make -s" 34 # Will be supressed by "make -s"
41 info() 35 info()
42 { 36 {
43 printf " %-7s %s\n" "${1}" "${2}" !! 37 if [ "${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
>> 44 modpost_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} ${objects}
>> 56 }
>> 57
>> 58 objtool_link()
>> 59 {
>> 60 local objtoolopt;
>> 61
>> 62 if [ -n "${CONFIG_VMLINUX_VALIDATION}" ]; then
>> 63 objtoolopt="check"
>> 64 if [ -z "${CONFIG_FRAME_POINTER}" ]; then
>> 65 objtoolopt="${objtoolopt} --no-fp"
>> 66 fi
>> 67 if [ -n "${CONFIG_GCOV_KERNEL}" ]; then
>> 68 objtoolopt="${objtoolopt} --no-unreachable"
>> 69 fi
>> 70 if [ -n "${CONFIG_RETPOLINE}" ]; then
>> 71 objtoolopt="${objtoolopt} --retpoline"
>> 72 fi
>> 73 if [ -n "${CONFIG_X86_SMAP}" ]; then
>> 74 objtoolopt="${objtoolopt} --uaccess"
>> 75 fi
>> 76 info OBJTOOL ${1}
>> 77 tools/objtool/objtool ${objtoolopt} ${1}
>> 78 fi
44 } 79 }
45 80
46 # Link of vmlinux 81 # Link of vmlinux
47 # ${1} - output file 82 # ${1} - output file
>> 83 # ${2}, ${3}, ... - optional extra .o files
48 vmlinux_link() 84 vmlinux_link()
49 { 85 {
>> 86 local lds="${objtree}/${KBUILD_LDS}"
50 local output=${1} 87 local output=${1}
51 local objs !! 88 local objects
52 local libs !! 89 local strip_debug
53 local ld <<
54 local ldflags <<
55 local ldlibs <<
56 90
57 info LD ${output} 91 info LD ${output}
58 92
59 # skip output file argument 93 # skip output file argument
60 shift 94 shift
61 95
62 if is_enabled CONFIG_LTO_CLANG || is_e <<
63 # Use vmlinux.o instead of per <<
64 objs=vmlinux.o <<
65 libs= <<
66 else <<
67 objs=vmlinux.a <<
68 libs="${KBUILD_VMLINUX_LIBS}" <<
69 fi <<
70 <<
71 if is_enabled CONFIG_MODULES; then <<
72 objs="${objs} .vmlinux.export. <<
73 fi <<
74 <<
75 objs="${objs} init/version-timestamp.o <<
76 <<
77 if [ "${SRCARCH}" = "um" ]; then <<
78 wl=-Wl, <<
79 ld="${CC}" <<
80 ldflags="${CFLAGS_vmlinux}" <<
81 ldlibs="-lutil -lrt -lpthread" <<
82 else <<
83 wl= <<
84 ld="${LD}" <<
85 ldflags="${KBUILD_LDFLAGS} ${L <<
86 ldlibs= <<
87 fi <<
88 <<
89 ldflags="${ldflags} ${wl}--script=${ob <<
90 <<
91 # The kallsyms linking does not need d 96 # The kallsyms linking does not need debug symbols included.
92 if [ -n "${strip_debug}" ] ; then !! 97 if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
93 ldflags="${ldflags} ${wl}--str !! 98 strip_debug=-Wl,--strip-debug
94 fi 99 fi
95 100
96 if is_enabled CONFIG_VMLINUX_MAP; then !! 101 if [ "${SRCARCH}" != "um" ]; then
97 ldflags="${ldflags} ${wl}-Map= !! 102 objects="--whole-archive \
>> 103 ${KBUILD_VMLINUX_OBJS} \
>> 104 --no-whole-archive \
>> 105 --start-group \
>> 106 ${KBUILD_VMLINUX_LIBS} \
>> 107 --end-group \
>> 108 ${@}"
>> 109
>> 110 ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
>> 111 ${strip_debug#-Wl,} \
>> 112 -o ${output} \
>> 113 -T ${lds} ${objects}
>> 114 else
>> 115 objects="-Wl,--whole-archive \
>> 116 ${KBUILD_VMLINUX_OBJS} \
>> 117 -Wl,--no-whole-archive \
>> 118 -Wl,--start-group \
>> 119 ${KBUILD_VMLINUX_LIBS} \
>> 120 -Wl,--end-group \
>> 121 ${@}"
>> 122
>> 123 ${CC} ${CFLAGS_vmlinux} \
>> 124 ${strip_debug} \
>> 125 -o ${output} \
>> 126 -Wl,-T,${lds} \
>> 127 ${objects} \
>> 128 -lutil -lrt -lpthread
>> 129 rm -f linux
98 fi 130 fi
99 <<
100 ${ld} ${ldflags} -o ${output} <<
101 ${wl}--whole-archive ${objs} $ <<
102 ${wl}--start-group ${libs} ${w <<
103 ${kallsymso} ${btf_vmlinux_bin <<
104 } 131 }
105 132
106 # generate .BTF typeinfo from DWARF debuginfo 133 # generate .BTF typeinfo from DWARF debuginfo
107 # ${1} - vmlinux image 134 # ${1} - vmlinux image
>> 135 # ${2} - file to dump raw BTF data into
108 gen_btf() 136 gen_btf()
109 { 137 {
110 local pahole_ver 138 local pahole_ver
111 local btf_data=${1}.btf.o <<
112 139
113 if ! [ -x "$(command -v ${PAHOLE})" ]; 140 if ! [ -x "$(command -v ${PAHOLE})" ]; then
114 echo >&2 "BTF: ${1}: pahole ($ 141 echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
115 return 1 142 return 1
116 fi 143 fi
117 144
118 pahole_ver=$(${PAHOLE} --version | sed 145 pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
119 if [ "${pahole_ver}" -lt "116" ]; then 146 if [ "${pahole_ver}" -lt "116" ]; then
120 echo >&2 "BTF: ${1}: pahole ve 147 echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16"
121 return 1 148 return 1
122 fi 149 fi
123 150
124 info BTF "${btf_data}" !! 151 vmlinux_link ${1}
125 LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J <<
126 152
127 # Create ${btf_data} which contains ju !! 153 info "BTF" ${2}
>> 154 LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
>> 155
>> 156 # Create ${2} which contains just .BTF section but no symbols. Add
128 # SHF_ALLOC because .BTF will be part 157 # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
129 # deletes all symbols including __star 158 # deletes all symbols including __start_BTF and __stop_BTF, which will
130 # be redefined in the linker script. A 159 # be redefined in the linker script. Add 2>/dev/null to suppress GNU
131 # objcopy warnings: "empty loadable se 160 # objcopy warnings: "empty loadable segment detected at ..."
132 ${OBJCOPY} --only-section=.BTF --set-s 161 ${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
133 --strip-all ${1} "${btf_data}" !! 162 --strip-all ${1} ${2} 2>/dev/null
134 # Change e_type to ET_REL so that it c 163 # Change e_type to ET_REL so that it can be used to link final vmlinux.
135 # GNU ld 2.35+ and lld do not allow an !! 164 # Unlike GNU ld, lld does not allow an ET_EXEC input.
136 if is_enabled CONFIG_CPU_BIG_ENDIAN; t !! 165 printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
137 et_rel='\0\1' <<
138 else <<
139 et_rel='\1\0' <<
140 fi <<
141 printf "${et_rel}" | dd of="${btf_data <<
142 <<
143 btf_vmlinux_bin_o=${btf_data} <<
144 } 166 }
145 167
146 # Create ${2}.o file with all symbols from the !! 168 # Create ${2} .o file with all symbols from the ${1} object file
147 kallsyms() 169 kallsyms()
148 { 170 {
>> 171 info KSYM ${2}
149 local kallsymopt; 172 local kallsymopt;
150 173
151 if is_enabled CONFIG_KALLSYMS_ALL; the !! 174 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
152 kallsymopt="${kallsymopt} --al 175 kallsymopt="${kallsymopt} --all-symbols"
153 fi 176 fi
154 177
155 if is_enabled CONFIG_KALLSYMS_ABSOLUTE !! 178 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
156 kallsymopt="${kallsymopt} --ab 179 kallsymopt="${kallsymopt} --absolute-percpu"
157 fi 180 fi
158 181
159 info KSYMS "${2}.S" !! 182 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
160 scripts/kallsyms ${kallsymopt} "${1}" !! 183 kallsymopt="${kallsymopt} --base-relative"
>> 184 fi
>> 185
>> 186 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
>> 187 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
161 188
162 info AS "${2}.o" !! 189 local afile="`basename ${2} .o`.S"
163 ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE <<
164 ${KBUILD_AFLAGS} ${KBUILD_AFLAGS <<
165 190
166 kallsymso=${2}.o !! 191 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
>> 192 ${CC} ${aflags} -c -o ${2} ${afile}
167 } 193 }
168 194
169 # Perform kallsyms for the given temporary vml !! 195 # Perform one step in kallsyms generation, including temporary linking of
170 sysmap_and_kallsyms() !! 196 # vmlinux.
>> 197 kallsyms_step()
171 { 198 {
172 mksysmap "${1}" "${1}.syms" !! 199 kallsymso_prev=${kallsymso}
173 kallsyms "${1}.syms" "${1}.kallsyms" !! 200 kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
>> 201 kallsymso=${kallsyms_vmlinux}.o
174 202
175 kallsyms_sysmap=${1}.syms !! 203 vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
>> 204 kallsyms ${kallsyms_vmlinux} ${kallsymso}
176 } 205 }
177 206
178 # Create map file with all symbols from ${1} 207 # Create map file with all symbols from ${1}
179 # See mksymap for additional details 208 # See mksymap for additional details
180 mksysmap() 209 mksysmap()
181 { 210 {
182 info NM ${2} !! 211 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
183 ${NM} -n "${1}" | sed -f "${srctree}/s <<
184 } 212 }
185 213
186 sorttable() 214 sorttable()
187 { 215 {
188 ${objtree}/scripts/sorttable ${1} 216 ${objtree}/scripts/sorttable ${1}
189 } 217 }
190 218
>> 219 # Delete output files in case of error
191 cleanup() 220 cleanup()
192 { 221 {
193 rm -f .btf.* 222 rm -f .btf.*
>> 223 rm -f .tmp_System.map
>> 224 rm -f .tmp_vmlinux*
194 rm -f System.map 225 rm -f System.map
195 rm -f vmlinux 226 rm -f vmlinux
196 rm -f vmlinux.map !! 227 rm -f vmlinux.o
>> 228 }
>> 229
>> 230 on_exit()
>> 231 {
>> 232 if [ $? -ne 0 ]; then
>> 233 cleanup
>> 234 fi
197 } 235 }
>> 236 trap on_exit EXIT
>> 237
>> 238 on_signals()
>> 239 {
>> 240 exit 1
>> 241 }
>> 242 trap on_signals HUP INT QUIT TERM
198 243
199 # Use "make V=1" to debug this script 244 # Use "make V=1" to debug this script
200 case "${KBUILD_VERBOSE}" in 245 case "${KBUILD_VERBOSE}" in
201 *1*) 246 *1*)
202 set -x 247 set -x
203 ;; 248 ;;
204 esac 249 esac
205 250
206 if [ "$1" = "clean" ]; then 251 if [ "$1" = "clean" ]; then
207 cleanup 252 cleanup
208 exit 0 253 exit 0
209 fi 254 fi
210 255
211 ${MAKE} -f "${srctree}/scripts/Makefile.build" !! 256 # We need access to CONFIG_ symbols
212 !! 257 . include/config/auto.conf
213 btf_vmlinux_bin_o= <<
214 kallsymso= <<
215 strip_debug= <<
216 <<
217 if is_enabled CONFIG_KALLSYMS; then <<
218 truncate -s0 .tmp_vmlinux.kallsyms0.sy <<
219 kallsyms .tmp_vmlinux.kallsyms0.syms . <<
220 fi <<
221 <<
222 if is_enabled CONFIG_KALLSYMS || is_enabled CO <<
223 <<
224 # The kallsyms linking does not need d <<
225 if ! is_enabled CONFIG_DEBUG_INFO_BTF; <<
226 strip_debug=1 <<
227 fi <<
228 <<
229 vmlinux_link .tmp_vmlinux1 <<
230 fi <<
231 258
232 if is_enabled CONFIG_DEBUG_INFO_BTF; then !! 259 # Update version
233 if ! gen_btf .tmp_vmlinux1; then !! 260 info GEN .version
>> 261 if [ -r .version ]; then
>> 262 VERSION=$(expr 0$(cat .version) + 1)
>> 263 echo $VERSION > .version
>> 264 else
>> 265 rm -f .version
>> 266 echo 1 > .version
>> 267 fi;
>> 268
>> 269 # final build of init/
>> 270 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
>> 271
>> 272 #link vmlinux.o
>> 273 info LD vmlinux.o
>> 274 modpost_link vmlinux.o
>> 275 objtool_link vmlinux.o
>> 276
>> 277 # modpost vmlinux.o to check for section mismatches
>> 278 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1
>> 279
>> 280 info MODINFO modules.builtin.modinfo
>> 281 ${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
>> 282 info GEN modules.builtin
>> 283 # The second line aids cases where multiple modules share the same object.
>> 284 tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' |
>> 285 tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin
>> 286
>> 287 btf_vmlinux_bin_o=""
>> 288 if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
>> 289 btf_vmlinux_bin_o=.btf.vmlinux.bin.o
>> 290 if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then
234 echo >&2 "Failed to generate B 291 echo >&2 "Failed to generate BTF for vmlinux"
235 echo >&2 "Try to disable CONFI 292 echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
236 exit 1 293 exit 1
237 fi 294 fi
238 fi 295 fi
239 296
240 if is_enabled CONFIG_KALLSYMS; then !! 297 kallsymso=""
>> 298 kallsymso_prev=""
>> 299 kallsyms_vmlinux=""
>> 300 if [ -n "${CONFIG_KALLSYMS}" ]; then
241 301
242 # kallsyms support 302 # kallsyms support
243 # Generate section listing all symbols 303 # Generate section listing all symbols and add it into vmlinux
244 # It's a four step process: !! 304 # It's a three step process:
245 # 0) Generate a dummy __kallsyms with !! 305 # 1) Link .tmp_vmlinux1 so it has all symbols and sections,
246 # 1) Link .tmp_vmlinux.kallsyms1 so i !! 306 # but __kallsyms is empty.
247 # with a dummy __kallsyms. <<
248 # Running kallsyms on that gives u 307 # Running kallsyms on that gives us .tmp_kallsyms1.o with
249 # the right size 308 # the right size
250 # 2) Link .tmp_vmlinux.kallsyms2 so i !! 309 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
251 # the right size, but due to the a 310 # the right size, but due to the added section, some
252 # addresses have shifted. 311 # addresses have shifted.
253 # From here, we generate a correct !! 312 # From here, we generate a correct .tmp_kallsyms2.o
254 # 3) That link may have expanded the 313 # 3) That link may have expanded the kernel image enough that
255 # more linker branch stubs / tramp 314 # more linker branch stubs / trampolines had to be added, which
256 # introduces new names, which furt 315 # introduces new names, which further expands kallsyms. Do another
257 # pass if that is the case. In the 316 # pass if that is the case. In theory it's possible this results
258 # in even more stubs, but unlikely 317 # in even more stubs, but unlikely.
259 # KALLSYMS_EXTRA_PASS=1 may also u 318 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
260 # other bugs. 319 # other bugs.
261 # 4) The correct ${kallsymso} is link 320 # 4) The correct ${kallsymso} is linked into the final vmlinux.
262 # 321 #
263 # a) Verify that the System.map from 322 # a) Verify that the System.map from vmlinux matches the map from
264 # ${kallsymso}. 323 # ${kallsymso}.
265 324
266 # The kallsyms linking does not need d !! 325 kallsyms_step 1
267 strip_debug=1 !! 326 kallsyms_step 2
268 327
269 sysmap_and_kallsyms .tmp_vmlinux1 !! 328 # step 3
270 size1=$(${CONFIG_SHELL} "${srctree}/sc !! 329 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev})
271 <<
272 vmlinux_link .tmp_vmlinux2 <<
273 sysmap_and_kallsyms .tmp_vmlinux2 <<
274 size2=$(${CONFIG_SHELL} "${srctree}/sc 330 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
275 331
276 if [ $size1 -ne $size2 ] || [ -n "${KA 332 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
277 vmlinux_link .tmp_vmlinux3 !! 333 kallsyms_step 3
278 sysmap_and_kallsyms .tmp_vmlin <<
279 fi 334 fi
280 fi 335 fi
281 336
282 strip_debug= !! 337 vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
283 <<
284 vmlinux_link vmlinux <<
285 <<
286 # fill in BTF IDs <<
287 if is_enabled CONFIG_DEBUG_INFO_BTF && is_enab <<
288 info BTFIDS vmlinux <<
289 ${RESOLVE_BTFIDS} vmlinux <<
290 fi <<
291 <<
292 mksysmap vmlinux System.map <<
293 338
294 if is_enabled CONFIG_BUILDTIME_TABLE_SORT; the !! 339 if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
295 info SORTTAB vmlinux 340 info SORTTAB vmlinux
296 if ! sorttable vmlinux; then 341 if ! sorttable vmlinux; then
297 echo >&2 Failed to sort kernel 342 echo >&2 Failed to sort kernel tables
298 exit 1 343 exit 1
299 fi 344 fi
300 fi 345 fi
301 346
>> 347 info SYSMAP System.map
>> 348 mksysmap vmlinux System.map
>> 349
302 # step a (see comment above) 350 # step a (see comment above)
303 if is_enabled CONFIG_KALLSYMS; then !! 351 if [ -n "${CONFIG_KALLSYMS}" ]; then
304 if ! cmp -s System.map "${kallsyms_sys !! 352 mksysmap ${kallsyms_vmlinux} .tmp_System.map
>> 353
>> 354 if ! cmp -s System.map .tmp_System.map; then
305 echo >&2 Inconsistent kallsyms 355 echo >&2 Inconsistent kallsyms data
306 echo >&2 'Try "make KALLSYMS_E !! 356 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
307 exit 1 357 exit 1
308 fi 358 fi
309 fi 359 fi
310 <<
311 # For fixdep <<
312 echo "vmlinux: $0" > .vmlinux.d <<
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.