1 #!/bin/sh
2 # SPDX-License-Identifier: GPL-2.0
3 #
4 # link vmlinux
5 #
6 # vmlinux is linked from the objects in vmlinu
7 # vmlinux.a contains objects that are linked u
8 # $(KBUILD_VMLINUX_LIBS) are archives which ar
9 # (not within --whole-archive), and do not req
10 #
11 # vmlinux
12 # ^
13 # |
14 # +--< vmlinux.a
15 # |
16 # +--< $(KBUILD_VMLINUX_LIBS)
17 # | +--< lib/lib.a + more
18 # |
19 # +-< ${kallsymso} (see description in KALLS
20 #
21 # vmlinux version (uname -v) cannot be updated
22 # descending-into-subdirs phase since we do no
23 # update vmlinux.
24 # Therefore this step is delayed until just be
25 #
26 # System.map is generated to document addresse
27
28 # Error out on error
29 set -e
30
31 LD="$1"
32 KBUILD_LDFLAGS="$2"
33 LDFLAGS_vmlinux="$3"
34
35 is_enabled() {
36 grep -q "^$1=y" include/config/auto.co
37 }
38
39 # Nice output in kbuild format
40 # Will be supressed by "make -s"
41 info()
42 {
43 printf " %-7s %s\n" "${1}" "${2}"
44 }
45
46 # Link of vmlinux
47 # ${1} - output file
48 vmlinux_link()
49 {
50 local output=${1}
51 local objs
52 local libs
53 local ld
54 local ldflags
55 local ldlibs
56
57 info LD ${output}
58
59 # skip output file argument
60 shift
61
62 if is_enabled CONFIG_LTO_CLANG || is_e
63 # Use vmlinux.o instead of per
64 objs=vmlinux.o
65 libs=
66 else
67 objs=vmlinux.a
68 libs="${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
92 if [ -n "${strip_debug}" ] ; then
93 ldflags="${ldflags} ${wl}--str
94 fi
95
96 if is_enabled CONFIG_VMLINUX_MAP; then
97 ldflags="${ldflags} ${wl}-Map=
98 fi
99
100 ${ld} ${ldflags} -o ${output}
101 ${wl}--whole-archive ${objs} $
102 ${wl}--start-group ${libs} ${w
103 ${kallsymso} ${btf_vmlinux_bin
104 }
105
106 # generate .BTF typeinfo from DWARF debuginfo
107 # ${1} - vmlinux image
108 gen_btf()
109 {
110 local pahole_ver
111 local btf_data=${1}.btf.o
112
113 if ! [ -x "$(command -v ${PAHOLE})" ];
114 echo >&2 "BTF: ${1}: pahole ($
115 return 1
116 fi
117
118 pahole_ver=$(${PAHOLE} --version | sed
119 if [ "${pahole_ver}" -lt "116" ]; then
120 echo >&2 "BTF: ${1}: pahole ve
121 return 1
122 fi
123
124 info BTF "${btf_data}"
125 LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J
126
127 # Create ${btf_data} which contains ju
128 # SHF_ALLOC because .BTF will be part
129 # deletes all symbols including __star
130 # be redefined in the linker script. A
131 # objcopy warnings: "empty loadable se
132 ${OBJCOPY} --only-section=.BTF --set-s
133 --strip-all ${1} "${btf_data}"
134 # Change e_type to ET_REL so that it c
135 # GNU ld 2.35+ and lld do not allow an
136 if is_enabled CONFIG_CPU_BIG_ENDIAN; t
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 }
145
146 # Create ${2}.o file with all symbols from the
147 kallsyms()
148 {
149 local kallsymopt;
150
151 if is_enabled CONFIG_KALLSYMS_ALL; the
152 kallsymopt="${kallsymopt} --al
153 fi
154
155 if is_enabled CONFIG_KALLSYMS_ABSOLUTE
156 kallsymopt="${kallsymopt} --ab
157 fi
158
159 info KSYMS "${2}.S"
160 scripts/kallsyms ${kallsymopt} "${1}"
161
162 info AS "${2}.o"
163 ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE
164 ${KBUILD_AFLAGS} ${KBUILD_AFLAGS
165
166 kallsymso=${2}.o
167 }
168
169 # Perform kallsyms for the given temporary vml
170 sysmap_and_kallsyms()
171 {
172 mksysmap "${1}" "${1}.syms"
173 kallsyms "${1}.syms" "${1}.kallsyms"
174
175 kallsyms_sysmap=${1}.syms
176 }
177
178 # Create map file with all symbols from ${1}
179 # See mksymap for additional details
180 mksysmap()
181 {
182 info NM ${2}
183 ${NM} -n "${1}" | sed -f "${srctree}/s
184 }
185
186 sorttable()
187 {
188 ${objtree}/scripts/sorttable ${1}
189 }
190
191 cleanup()
192 {
193 rm -f .btf.*
194 rm -f System.map
195 rm -f vmlinux
196 rm -f vmlinux.map
197 }
198
199 # Use "make V=1" to debug this script
200 case "${KBUILD_VERBOSE}" in
201 *1*)
202 set -x
203 ;;
204 esac
205
206 if [ "$1" = "clean" ]; then
207 cleanup
208 exit 0
209 fi
210
211 ${MAKE} -f "${srctree}/scripts/Makefile.build"
212
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
232 if is_enabled CONFIG_DEBUG_INFO_BTF; then
233 if ! gen_btf .tmp_vmlinux1; then
234 echo >&2 "Failed to generate B
235 echo >&2 "Try to disable CONFI
236 exit 1
237 fi
238 fi
239
240 if is_enabled CONFIG_KALLSYMS; then
241
242 # kallsyms support
243 # Generate section listing all symbols
244 # It's a four step process:
245 # 0) Generate a dummy __kallsyms with
246 # 1) Link .tmp_vmlinux.kallsyms1 so i
247 # with a dummy __kallsyms.
248 # Running kallsyms on that gives u
249 # the right size
250 # 2) Link .tmp_vmlinux.kallsyms2 so i
251 # the right size, but due to the a
252 # addresses have shifted.
253 # From here, we generate a correct
254 # 3) That link may have expanded the
255 # more linker branch stubs / tramp
256 # introduces new names, which furt
257 # pass if that is the case. In the
258 # in even more stubs, but unlikely
259 # KALLSYMS_EXTRA_PASS=1 may also u
260 # other bugs.
261 # 4) The correct ${kallsymso} is link
262 #
263 # a) Verify that the System.map from
264 # ${kallsymso}.
265
266 # The kallsyms linking does not need d
267 strip_debug=1
268
269 sysmap_and_kallsyms .tmp_vmlinux1
270 size1=$(${CONFIG_SHELL} "${srctree}/sc
271
272 vmlinux_link .tmp_vmlinux2
273 sysmap_and_kallsyms .tmp_vmlinux2
274 size2=$(${CONFIG_SHELL} "${srctree}/sc
275
276 if [ $size1 -ne $size2 ] || [ -n "${KA
277 vmlinux_link .tmp_vmlinux3
278 sysmap_and_kallsyms .tmp_vmlin
279 fi
280 fi
281
282 strip_debug=
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 ${RESOLVE_BTFIDS} vmlinux
290 fi
291
292 mksysmap vmlinux System.map
293
294 if is_enabled CONFIG_BUILDTIME_TABLE_SORT; the
295 info SORTTAB vmlinux
296 if ! sorttable vmlinux; then
297 echo >&2 Failed to sort kernel
298 exit 1
299 fi
300 fi
301
302 # step a (see comment above)
303 if is_enabled CONFIG_KALLSYMS; then
304 if ! cmp -s System.map "${kallsyms_sys
305 echo >&2 Inconsistent kallsyms
306 echo >&2 'Try "make KALLSYMS_E
307 exit 1
308 fi
309 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.