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 in vmlinux.a and $(KBUILD_VMLINUX_LIBS).
7 # vmlinux.a contains objects that are linked u 7 # vmlinux.a contains objects that are linked unconditionally.
8 # $(KBUILD_VMLINUX_LIBS) are archives which ar 8 # $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally
9 # (not within --whole-archive), and do not req 9 # (not within --whole-archive), and do not require symbol indexes added.
10 # 10 #
11 # vmlinux 11 # vmlinux
12 # ^ 12 # ^
13 # | 13 # |
14 # +--< vmlinux.a 14 # +--< vmlinux.a
15 # | 15 # |
16 # +--< $(KBUILD_VMLINUX_LIBS) 16 # +--< $(KBUILD_VMLINUX_LIBS)
17 # | +--< lib/lib.a + more 17 # | +--< lib/lib.a + more
18 # | 18 # |
19 # +-< ${kallsymso} (see description in KALLS 19 # +-< ${kallsymso} (see description in KALLSYMS section)
20 # 20 #
21 # vmlinux version (uname -v) cannot be updated 21 # vmlinux version (uname -v) cannot be updated during normal
22 # descending-into-subdirs phase since we do no 22 # descending-into-subdirs phase since we do not yet know if we need to
23 # update vmlinux. 23 # update vmlinux.
24 # Therefore this step is delayed until just be 24 # Therefore this step is delayed until just before final link of vmlinux.
25 # 25 #
26 # System.map is generated to document addresse 26 # System.map is generated to document addresses of all kernel symbols
27 27
28 # Error out on error 28 # Error out on error
29 set -e 29 set -e
30 30
31 LD="$1" 31 LD="$1"
32 KBUILD_LDFLAGS="$2" 32 KBUILD_LDFLAGS="$2"
33 LDFLAGS_vmlinux="$3" 33 LDFLAGS_vmlinux="$3"
34 34
35 is_enabled() { 35 is_enabled() {
36 grep -q "^$1=y" include/config/auto.co 36 grep -q "^$1=y" include/config/auto.conf
37 } 37 }
38 38
39 # Nice output in kbuild format 39 # Nice output in kbuild format
40 # Will be supressed by "make -s" 40 # Will be supressed by "make -s"
41 info() 41 info()
42 { 42 {
43 printf " %-7s %s\n" "${1}" "${2}" 43 printf " %-7s %s\n" "${1}" "${2}"
44 } 44 }
45 45
46 # Link of vmlinux 46 # Link of vmlinux
47 # ${1} - output file 47 # ${1} - output file
48 vmlinux_link() 48 vmlinux_link()
49 { 49 {
50 local output=${1} 50 local output=${1}
51 local objs 51 local objs
52 local libs 52 local libs
53 local ld 53 local ld
54 local ldflags 54 local ldflags
55 local ldlibs 55 local ldlibs
56 56
57 info LD ${output} 57 info LD ${output}
58 58
59 # skip output file argument 59 # skip output file argument
60 shift 60 shift
61 61
62 if is_enabled CONFIG_LTO_CLANG || is_e 62 if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
63 # Use vmlinux.o instead of per 63 # Use vmlinux.o instead of performing the slow LTO link again.
64 objs=vmlinux.o 64 objs=vmlinux.o
65 libs= 65 libs=
66 else 66 else
67 objs=vmlinux.a 67 objs=vmlinux.a
68 libs="${KBUILD_VMLINUX_LIBS}" 68 libs="${KBUILD_VMLINUX_LIBS}"
69 fi 69 fi
70 70
71 if is_enabled CONFIG_MODULES; then 71 if is_enabled CONFIG_MODULES; then
72 objs="${objs} .vmlinux.export. 72 objs="${objs} .vmlinux.export.o"
73 fi 73 fi
74 74
75 objs="${objs} init/version-timestamp.o 75 objs="${objs} init/version-timestamp.o"
76 76
77 if [ "${SRCARCH}" = "um" ]; then 77 if [ "${SRCARCH}" = "um" ]; then
78 wl=-Wl, 78 wl=-Wl,
79 ld="${CC}" 79 ld="${CC}"
80 ldflags="${CFLAGS_vmlinux}" 80 ldflags="${CFLAGS_vmlinux}"
81 ldlibs="-lutil -lrt -lpthread" 81 ldlibs="-lutil -lrt -lpthread"
82 else 82 else
83 wl= 83 wl=
84 ld="${LD}" 84 ld="${LD}"
85 ldflags="${KBUILD_LDFLAGS} ${L 85 ldflags="${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux}"
86 ldlibs= 86 ldlibs=
87 fi 87 fi
88 88
89 ldflags="${ldflags} ${wl}--script=${ob 89 ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}"
90 90
91 # The kallsyms linking does not need d 91 # The kallsyms linking does not need debug symbols included.
92 if [ -n "${strip_debug}" ] ; then 92 if [ -n "${strip_debug}" ] ; then
93 ldflags="${ldflags} ${wl}--str 93 ldflags="${ldflags} ${wl}--strip-debug"
94 fi 94 fi
95 95
96 if is_enabled CONFIG_VMLINUX_MAP; then 96 if is_enabled CONFIG_VMLINUX_MAP; then
97 ldflags="${ldflags} ${wl}-Map= 97 ldflags="${ldflags} ${wl}-Map=${output}.map"
98 fi 98 fi
99 99
100 ${ld} ${ldflags} -o ${output} 100 ${ld} ${ldflags} -o ${output} \
101 ${wl}--whole-archive ${objs} $ 101 ${wl}--whole-archive ${objs} ${wl}--no-whole-archive \
102 ${wl}--start-group ${libs} ${w 102 ${wl}--start-group ${libs} ${wl}--end-group \
103 ${kallsymso} ${btf_vmlinux_bin 103 ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs}
104 } 104 }
105 105
106 # generate .BTF typeinfo from DWARF debuginfo 106 # generate .BTF typeinfo from DWARF debuginfo
107 # ${1} - vmlinux image 107 # ${1} - vmlinux image
108 gen_btf() 108 gen_btf()
109 { 109 {
110 local pahole_ver 110 local pahole_ver
111 local btf_data=${1}.btf.o 111 local btf_data=${1}.btf.o
112 112
113 if ! [ -x "$(command -v ${PAHOLE})" ]; 113 if ! [ -x "$(command -v ${PAHOLE})" ]; then
114 echo >&2 "BTF: ${1}: pahole ($ 114 echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
115 return 1 115 return 1
116 fi 116 fi
117 117
118 pahole_ver=$(${PAHOLE} --version | sed 118 pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
119 if [ "${pahole_ver}" -lt "116" ]; then 119 if [ "${pahole_ver}" -lt "116" ]; then
120 echo >&2 "BTF: ${1}: pahole ve 120 echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.16"
121 return 1 121 return 1
122 fi 122 fi
123 123
124 info BTF "${btf_data}" 124 info BTF "${btf_data}"
125 LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J 125 LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
126 126
127 # Create ${btf_data} which contains ju 127 # Create ${btf_data} which contains just .BTF section but no symbols. Add
128 # SHF_ALLOC because .BTF will be part 128 # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
129 # deletes all symbols including __star 129 # deletes all symbols including __start_BTF and __stop_BTF, which will
130 # be redefined in the linker script. A 130 # be redefined in the linker script. Add 2>/dev/null to suppress GNU
131 # objcopy warnings: "empty loadable se 131 # objcopy warnings: "empty loadable segment detected at ..."
132 ${OBJCOPY} --only-section=.BTF --set-s 132 ${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \
133 --strip-all ${1} "${btf_data}" 133 --strip-all ${1} "${btf_data}" 2>/dev/null
134 # Change e_type to ET_REL so that it c 134 # 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 135 # GNU ld 2.35+ and lld do not allow an ET_EXEC input.
136 if is_enabled CONFIG_CPU_BIG_ENDIAN; t 136 if is_enabled CONFIG_CPU_BIG_ENDIAN; then
137 et_rel='\0\1' 137 et_rel='\0\1'
138 else 138 else
139 et_rel='\1\0' 139 et_rel='\1\0'
140 fi 140 fi
141 printf "${et_rel}" | dd of="${btf_data 141 printf "${et_rel}" | dd of="${btf_data}" conv=notrunc bs=1 seek=16 status=none
142 142
143 btf_vmlinux_bin_o=${btf_data} 143 btf_vmlinux_bin_o=${btf_data}
144 } 144 }
145 145
146 # Create ${2}.o file with all symbols from the 146 # Create ${2}.o file with all symbols from the ${1} object file
147 kallsyms() 147 kallsyms()
148 { 148 {
149 local kallsymopt; 149 local kallsymopt;
150 150
151 if is_enabled CONFIG_KALLSYMS_ALL; the 151 if is_enabled CONFIG_KALLSYMS_ALL; then
152 kallsymopt="${kallsymopt} --al 152 kallsymopt="${kallsymopt} --all-symbols"
153 fi 153 fi
154 154
155 if is_enabled CONFIG_KALLSYMS_ABSOLUTE 155 if is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU; then
156 kallsymopt="${kallsymopt} --ab 156 kallsymopt="${kallsymopt} --absolute-percpu"
157 fi 157 fi
158 158
159 info KSYMS "${2}.S" 159 info KSYMS "${2}.S"
160 scripts/kallsyms ${kallsymopt} "${1}" 160 scripts/kallsyms ${kallsymopt} "${1}" > "${2}.S"
161 161
162 info AS "${2}.o" 162 info AS "${2}.o"
163 ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE 163 ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
164 ${KBUILD_AFLAGS} ${KBUILD_AFLAGS 164 ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} -c -o "${2}.o" "${2}.S"
165 165
166 kallsymso=${2}.o 166 kallsymso=${2}.o
167 } 167 }
168 168
169 # Perform kallsyms for the given temporary vml 169 # Perform kallsyms for the given temporary vmlinux.
170 sysmap_and_kallsyms() 170 sysmap_and_kallsyms()
171 { 171 {
172 mksysmap "${1}" "${1}.syms" 172 mksysmap "${1}" "${1}.syms"
173 kallsyms "${1}.syms" "${1}.kallsyms" 173 kallsyms "${1}.syms" "${1}.kallsyms"
174 174
175 kallsyms_sysmap=${1}.syms 175 kallsyms_sysmap=${1}.syms
176 } 176 }
177 177
178 # Create map file with all symbols from ${1} 178 # Create map file with all symbols from ${1}
179 # See mksymap for additional details 179 # See mksymap for additional details
180 mksysmap() 180 mksysmap()
181 { 181 {
182 info NM ${2} 182 info NM ${2}
183 ${NM} -n "${1}" | sed -f "${srctree}/s 183 ${NM} -n "${1}" | sed -f "${srctree}/scripts/mksysmap" > "${2}"
184 } 184 }
185 185
186 sorttable() 186 sorttable()
187 { 187 {
188 ${objtree}/scripts/sorttable ${1} 188 ${objtree}/scripts/sorttable ${1}
189 } 189 }
190 190
191 cleanup() 191 cleanup()
192 { 192 {
193 rm -f .btf.* 193 rm -f .btf.*
194 rm -f System.map 194 rm -f System.map
195 rm -f vmlinux 195 rm -f vmlinux
196 rm -f vmlinux.map 196 rm -f vmlinux.map
197 } 197 }
198 198
199 # Use "make V=1" to debug this script 199 # Use "make V=1" to debug this script
200 case "${KBUILD_VERBOSE}" in 200 case "${KBUILD_VERBOSE}" in
201 *1*) 201 *1*)
202 set -x 202 set -x
203 ;; 203 ;;
204 esac 204 esac
205 205
206 if [ "$1" = "clean" ]; then 206 if [ "$1" = "clean" ]; then
207 cleanup 207 cleanup
208 exit 0 208 exit 0
209 fi 209 fi
210 210
211 ${MAKE} -f "${srctree}/scripts/Makefile.build" 211 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init init/version-timestamp.o
212 212
213 btf_vmlinux_bin_o= 213 btf_vmlinux_bin_o=
214 kallsymso= 214 kallsymso=
215 strip_debug= 215 strip_debug=
216 216
217 if is_enabled CONFIG_KALLSYMS; then 217 if is_enabled CONFIG_KALLSYMS; then
218 truncate -s0 .tmp_vmlinux.kallsyms0.sy 218 truncate -s0 .tmp_vmlinux.kallsyms0.syms
219 kallsyms .tmp_vmlinux.kallsyms0.syms . 219 kallsyms .tmp_vmlinux.kallsyms0.syms .tmp_vmlinux0.kallsyms
220 fi 220 fi
221 221
222 if is_enabled CONFIG_KALLSYMS || is_enabled CO 222 if is_enabled CONFIG_KALLSYMS || is_enabled CONFIG_DEBUG_INFO_BTF; then
223 223
224 # The kallsyms linking does not need d 224 # The kallsyms linking does not need debug symbols, but the BTF does.
225 if ! is_enabled CONFIG_DEBUG_INFO_BTF; 225 if ! is_enabled CONFIG_DEBUG_INFO_BTF; then
226 strip_debug=1 226 strip_debug=1
227 fi 227 fi
228 228
229 vmlinux_link .tmp_vmlinux1 229 vmlinux_link .tmp_vmlinux1
230 fi 230 fi
231 231
232 if is_enabled CONFIG_DEBUG_INFO_BTF; then 232 if is_enabled CONFIG_DEBUG_INFO_BTF; then
233 if ! gen_btf .tmp_vmlinux1; then 233 if ! gen_btf .tmp_vmlinux1; then
234 echo >&2 "Failed to generate B 234 echo >&2 "Failed to generate BTF for vmlinux"
235 echo >&2 "Try to disable CONFI 235 echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
236 exit 1 236 exit 1
237 fi 237 fi
238 fi 238 fi
239 239
240 if is_enabled CONFIG_KALLSYMS; then 240 if is_enabled CONFIG_KALLSYMS; then
241 241
242 # kallsyms support 242 # kallsyms support
243 # Generate section listing all symbols 243 # Generate section listing all symbols and add it into vmlinux
244 # It's a four step process: 244 # It's a four step process:
245 # 0) Generate a dummy __kallsyms with 245 # 0) Generate a dummy __kallsyms with empty symbol list.
246 # 1) Link .tmp_vmlinux.kallsyms1 so i 246 # 1) Link .tmp_vmlinux.kallsyms1 so it has all symbols and sections,
247 # with a dummy __kallsyms. 247 # with a dummy __kallsyms.
248 # Running kallsyms on that gives u 248 # Running kallsyms on that gives us .tmp_kallsyms1.o with
249 # the right size 249 # the right size
250 # 2) Link .tmp_vmlinux.kallsyms2 so i 250 # 2) Link .tmp_vmlinux.kallsyms2 so it now has a __kallsyms section of
251 # the right size, but due to the a 251 # the right size, but due to the added section, some
252 # addresses have shifted. 252 # addresses have shifted.
253 # From here, we generate a correct 253 # From here, we generate a correct .tmp_vmlinux.kallsyms2.o
254 # 3) That link may have expanded the 254 # 3) That link may have expanded the kernel image enough that
255 # more linker branch stubs / tramp 255 # more linker branch stubs / trampolines had to be added, which
256 # introduces new names, which furt 256 # introduces new names, which further expands kallsyms. Do another
257 # pass if that is the case. In the 257 # pass if that is the case. In theory it's possible this results
258 # in even more stubs, but unlikely 258 # in even more stubs, but unlikely.
259 # KALLSYMS_EXTRA_PASS=1 may also u 259 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
260 # other bugs. 260 # other bugs.
261 # 4) The correct ${kallsymso} is link 261 # 4) The correct ${kallsymso} is linked into the final vmlinux.
262 # 262 #
263 # a) Verify that the System.map from 263 # a) Verify that the System.map from vmlinux matches the map from
264 # ${kallsymso}. 264 # ${kallsymso}.
265 265
266 # The kallsyms linking does not need d 266 # The kallsyms linking does not need debug symbols included.
267 strip_debug=1 267 strip_debug=1
268 268
269 sysmap_and_kallsyms .tmp_vmlinux1 269 sysmap_and_kallsyms .tmp_vmlinux1
270 size1=$(${CONFIG_SHELL} "${srctree}/sc 270 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
271 271
272 vmlinux_link .tmp_vmlinux2 272 vmlinux_link .tmp_vmlinux2
273 sysmap_and_kallsyms .tmp_vmlinux2 273 sysmap_and_kallsyms .tmp_vmlinux2
274 size2=$(${CONFIG_SHELL} "${srctree}/sc 274 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso})
275 275
276 if [ $size1 -ne $size2 ] || [ -n "${KA 276 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
277 vmlinux_link .tmp_vmlinux3 277 vmlinux_link .tmp_vmlinux3
278 sysmap_and_kallsyms .tmp_vmlin 278 sysmap_and_kallsyms .tmp_vmlinux3
279 fi 279 fi
280 fi 280 fi
281 281
282 strip_debug= 282 strip_debug=
283 283
284 vmlinux_link vmlinux 284 vmlinux_link vmlinux
285 285
286 # fill in BTF IDs 286 # fill in BTF IDs
287 if is_enabled CONFIG_DEBUG_INFO_BTF && is_enab 287 if is_enabled CONFIG_DEBUG_INFO_BTF && is_enabled CONFIG_BPF; then
288 info BTFIDS vmlinux 288 info BTFIDS vmlinux
289 ${RESOLVE_BTFIDS} vmlinux 289 ${RESOLVE_BTFIDS} vmlinux
290 fi 290 fi
291 291
292 mksysmap vmlinux System.map 292 mksysmap vmlinux System.map
293 293
294 if is_enabled CONFIG_BUILDTIME_TABLE_SORT; the 294 if is_enabled CONFIG_BUILDTIME_TABLE_SORT; then
295 info SORTTAB vmlinux 295 info SORTTAB vmlinux
296 if ! sorttable vmlinux; then 296 if ! sorttable vmlinux; then
297 echo >&2 Failed to sort kernel 297 echo >&2 Failed to sort kernel tables
298 exit 1 298 exit 1
299 fi 299 fi
300 fi 300 fi
301 301
302 # step a (see comment above) 302 # step a (see comment above)
303 if is_enabled CONFIG_KALLSYMS; then 303 if is_enabled CONFIG_KALLSYMS; then
304 if ! cmp -s System.map "${kallsyms_sys 304 if ! cmp -s System.map "${kallsyms_sysmap}"; then
305 echo >&2 Inconsistent kallsyms 305 echo >&2 Inconsistent kallsyms data
306 echo >&2 'Try "make KALLSYMS_E 306 echo >&2 'Try "make KALLSYMS_EXTRA_PASS=1" as a workaround'
307 exit 1 307 exit 1
308 fi 308 fi
309 fi 309 fi
310 310
311 # For fixdep 311 # For fixdep
312 echo "vmlinux: $0" > .vmlinux.d 312 echo "vmlinux: $0" > .vmlinux.d
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