projects/linux·blob v5.3-rc5 · refs

294 lines · 6.8 KiB

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# +-< ${kallsymso} (see description in KALLSYMS section)
22#
23# vmlinux version (uname -v) cannot be updated during normal
24# descending-into-subdirs phase since we do not yet know if we need to
25# update vmlinux.
26# Therefore this step is delayed until just before final link of vmlinux.
27#
28# System.map is generated to document addresses of all kernel symbols
29
30# Error out on error
31set -e
32
33# Nice output in kbuild format
34# Will be supressed by "make -s"
35info()
36{
37 if [ "${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
44modpost_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# Link of vmlinux
59# ${1} - optional extra .o files
60# ${2} - output file
61vmlinux_link()
62{
63 local lds="${objtree}/${KBUILD_LDS}"
64 local objects
65
66 if [ "${SRCARCH}" != "um" ]; then
67 objects="--whole-archive \
68 ${KBUILD_VMLINUX_OBJS} \
69 --no-whole-archive \
70 --start-group \
71 ${KBUILD_VMLINUX_LIBS} \
72 --end-group \
73 ${1}"
74
75 ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
76 -T ${lds} ${objects}
77 else
78 objects="-Wl,--whole-archive \
79 ${KBUILD_VMLINUX_OBJS} \
80 -Wl,--no-whole-archive \
81 -Wl,--start-group \
82 ${KBUILD_VMLINUX_LIBS} \
83 -Wl,--end-group \
84 ${1}"
85
86 ${CC} ${CFLAGS_vmlinux} -o ${2} \
87 -Wl,-T,${lds} \
88 ${objects} \
89 -lutil -lrt -lpthread
90 rm -f linux
91 fi
92}
93
94# generate .BTF typeinfo from DWARF debuginfo
95gen_btf()
96{
97 local pahole_ver;
98
99 if ! [ -x "$(command -v ${PAHOLE})" ]; then
100 info "BTF" "${1}: pahole (${PAHOLE}) is not available"
101 return 0
102 fi
103
104 pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
105 if [ "${pahole_ver}" -lt "113" ]; then
106 info "BTF" "${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13"
107 return 0
108 fi
109
110 info "BTF" ${1}
111 LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
112}
113
114# Create ${2} .o file with all symbols from the ${1} object file
115kallsyms()
116{
117 info KSYM ${2}
118 local kallsymopt;
119
120 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
121 kallsymopt="${kallsymopt} --all-symbols"
122 fi
123
124 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
125 kallsymopt="${kallsymopt} --absolute-percpu"
126 fi
127
128 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
129 kallsymopt="${kallsymopt} --base-relative"
130 fi
131
132 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
133 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
134
135 local afile="`basename ${2} .o`.S"
136
137 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
138 ${CC} ${aflags} -c -o ${2} ${afile}
139}
140
141# Create map file with all symbols from ${1}
142# See mksymap for additional details
143mksysmap()
144{
145 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
146}
147
148sortextable()
149{
150 ${objtree}/scripts/sortextable ${1}
151}
152
153# Delete output files in case of error
154cleanup()
155{
156 rm -f .tmp_System.map
157 rm -f .tmp_kallsyms*
158 rm -f .tmp_vmlinux*
159 rm -f System.map
160 rm -f vmlinux
161 rm -f vmlinux.o
162}
163
164on_exit()
165{
166 if [ $? -ne 0 ]; then
167 cleanup
168 fi
169}
170trap on_exit EXIT
171
172on_signals()
173{
174 exit 1
175}
176trap on_signals HUP INT QUIT TERM
177
178#
179#
180# Use "make V=1" to debug this script
181case "${KBUILD_VERBOSE}" in
182*1*)
183 set -x
184 ;;
185esac
186
187if [ "$1" = "clean" ]; then
188 cleanup
189 exit 0
190fi
191
192# We need access to CONFIG_ symbols
193. include/config/auto.conf
194
195# Update version
196info GEN .version
197if [ -r .version ]; then
198 VERSION=$(expr 0$(cat .version) + 1)
199 echo $VERSION > .version
200else
201 rm -f .version
202 echo 1 > .version
203fi;
204
205# final build of init/
206${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
207
208#link vmlinux.o
209info LD vmlinux.o
210modpost_link vmlinux.o
211
212# modpost vmlinux.o to check for section mismatches
213${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1
214
215info MODINFO modules.builtin.modinfo
216${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
217
218kallsymso=""
219kallsyms_vmlinux=""
220if [ -n "${CONFIG_KALLSYMS}" ]; then
221
222 # kallsyms support
223 # Generate section listing all symbols and add it into vmlinux
224 # It's a three step process:
225 # 1) Link .tmp_vmlinux1 so it has all symbols and sections,
226 # but __kallsyms is empty.
227 # Running kallsyms on that gives us .tmp_kallsyms1.o with
228 # the right size
229 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of
230 # the right size, but due to the added section, some
231 # addresses have shifted.
232 # From here, we generate a correct .tmp_kallsyms2.o
233 # 3) That link may have expanded the kernel image enough that
234 # more linker branch stubs / trampolines had to be added, which
235 # introduces new names, which further expands kallsyms. Do another
236 # pass if that is the case. In theory it's possible this results
237 # in even more stubs, but unlikely.
238 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
239 # other bugs.
240 # 4) The correct ${kallsymso} is linked into the final vmlinux.
241 #
242 # a) Verify that the System.map from vmlinux matches the map from
243 # ${kallsymso}.
244
245 kallsymso=.tmp_kallsyms2.o
246 kallsyms_vmlinux=.tmp_vmlinux2
247
248 # step 1
249 vmlinux_link "" .tmp_vmlinux1
250 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
251
252 # step 2
253 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
254 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
255
256 # step 3
257 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o)
258 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o)
259
260 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
261 kallsymso=.tmp_kallsyms3.o
262 kallsyms_vmlinux=.tmp_vmlinux3
263
264 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
265
266 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
267 fi
268fi
269
270info LD vmlinux
271vmlinux_link "${kallsymso}" vmlinux
272
273if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
274 gen_btf vmlinux
275fi
276
277if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
278 info SORTEX vmlinux
279 sortextable vmlinux
280fi
281
282info SYSMAP System.map
283mksysmap vmlinux System.map
284
285# step a (see comment above)
286if [ -n "${CONFIG_KALLSYMS}" ]; then
287 mksysmap ${kallsyms_vmlinux} .tmp_System.map
288
289 if ! cmp -s System.map .tmp_System.map; then
290 echo >&2 Inconsistent kallsyms data
291 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
292 exit 1
293 fi
294fi