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_INIT) and 7# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.o files 8# from top-level directories in the kernel tree, others are specified in 9# arch/$(ARCH)/Makefile. Ordering when linking is important, and 10# $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives 11# which are linked conditionally (not within --whole-archive), and do not 12# require symbol indexes added. 13# 14# vmlinux 15# ^ 16# | 17# +-< $(KBUILD_VMLINUX_INIT) 18# | +--< init/version.o + more 19# | 20# +--< $(KBUILD_VMLINUX_MAIN) 21# | +--< drivers/built-in.o mm/built-in.o + more 22# | 23# +--< $(KBUILD_VMLINUX_LIBS) 24# | +--< lib/lib.a + more 25# | 26# +-< ${kallsymso} (see description in KALLSYMS section) 27# 28# vmlinux version (uname -v) cannot be updated during normal 29# descending-into-subdirs phase since we do not yet know if we need to 30# update vmlinux. 31# Therefore this step is delayed until just before final link of vmlinux. 32# 33# System.map is generated to document addresses of all kernel symbols 34 35# Error out on error 36set -e 37 38# Nice output in kbuild format 39# Will be supressed by "make -s" 40info() 41{ 42 if [ "${quiet}" != "silent_" ]; then 43 printf " %-7s %s\n" ${1} ${2} 44 fi 45} 46 47# Thin archive build here makes a final archive with symbol table and indexes 48# from vmlinux objects INIT and MAIN, which can be used as input to linker. 49# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes 50# added. 51# 52# Traditional incremental style of link does not require this step 53# 54# built-in.o output file 55# 56archive_builtin() 57{ 58 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 59 info AR built-in.o 60 rm -f built-in.o; 61 ${AR} rcsTP${KBUILD_ARFLAGS} built-in.o \ 62 ${KBUILD_VMLINUX_INIT} \ 63 ${KBUILD_VMLINUX_MAIN} 64 fi 65} 66 67# Link of vmlinux.o used for section mismatch analysis 68# ${1} output file 69modpost_link() 70{ 71 local objects 72 73 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 74 objects="--whole-archive \ 75 built-in.o \ 76 --no-whole-archive \ 77 --start-group \ 78 ${KBUILD_VMLINUX_LIBS} \ 79 --end-group" 80 else 81 objects="${KBUILD_VMLINUX_INIT} \ 82 --start-group \ 83 ${KBUILD_VMLINUX_MAIN} \ 84 ${KBUILD_VMLINUX_LIBS} \ 85 --end-group" 86 fi 87 ${LD} ${LDFLAGS} -r -o ${1} ${objects} 88} 89 90# Link of vmlinux 91# ${1} - optional extra .o files 92# ${2} - output file 93vmlinux_link() 94{ 95 local lds="${objtree}/${KBUILD_LDS}" 96 local objects 97 98 if [ "${SRCARCH}" != "um" ]; then 99 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 100 objects="--whole-archive \ 101 built-in.o \ 102 --no-whole-archive \ 103 --start-group \ 104 ${KBUILD_VMLINUX_LIBS} \ 105 --end-group \ 106 ${1}" 107 else 108 objects="${KBUILD_VMLINUX_INIT} \ 109 --start-group \ 110 ${KBUILD_VMLINUX_MAIN} \ 111 ${KBUILD_VMLINUX_LIBS} \ 112 --end-group \ 113 ${1}" 114 fi 115 116 ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \ 117 -T ${lds} ${objects} 118 else 119 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 120 objects="-Wl,--whole-archive \ 121 built-in.o \ 122 -Wl,--no-whole-archive \ 123 -Wl,--start-group \ 124 ${KBUILD_VMLINUX_LIBS} \ 125 -Wl,--end-group \ 126 ${1}" 127 else 128 objects="${KBUILD_VMLINUX_INIT} \ 129 -Wl,--start-group \ 130 ${KBUILD_VMLINUX_MAIN} \ 131 ${KBUILD_VMLINUX_LIBS} \ 132 -Wl,--end-group \ 133 ${1}" 134 fi 135 136 ${CC} ${CFLAGS_vmlinux} -o ${2} \ 137 -Wl,-T,${lds} \ 138 ${objects} \ 139 -lutil -lrt -lpthread 140 rm -f linux 141 fi 142} 143 144 145# Create ${2} .o file with all symbols from the ${1} object file 146kallsyms() 147{ 148 info KSYM ${2} 149 local kallsymopt; 150 151 if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then 152 kallsymopt="${kallsymopt} --symbol-prefix=_" 153 fi 154 155 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then 156 kallsymopt="${kallsymopt} --all-symbols" 157 fi 158 159 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then 160 kallsymopt="${kallsymopt} --absolute-percpu" 161 fi 162 163 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then 164 kallsymopt="${kallsymopt} --base-relative" 165 fi 166 167 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ 168 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" 169 170 local afile="`basename ${2} .o`.S" 171 172 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile} 173 ${CC} ${aflags} -c -o ${2} ${afile} 174} 175 176# Create map file with all symbols from ${1} 177# See mksymap for additional details 178mksysmap() 179{ 180 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} 181} 182 183sortextable() 184{ 185 ${objtree}/scripts/sortextable ${1} 186} 187 188# Delete output files in case of error 189cleanup() 190{ 191 rm -f .tmp_System.map 192 rm -f .tmp_kallsyms* 193 rm -f .tmp_vmlinux* 194 rm -f built-in.o 195 rm -f System.map 196 rm -f vmlinux 197 rm -f vmlinux.o 198} 199 200on_exit() 201{ 202 if [ $? -ne 0 ]; then 203 cleanup 204 fi 205} 206trap on_exit EXIT 207 208on_signals() 209{ 210 exit 1 211} 212trap on_signals HUP INT QUIT TERM 213 214# 215# 216# Use "make V=1" to debug this script 217case "${KBUILD_VERBOSE}" in 218*1*) 219 set -x 220 ;; 221esac 222 223if [ "$1" = "clean" ]; then 224 cleanup 225 exit 0 226fi 227 228# We need access to CONFIG_ symbols 229case "${KCONFIG_CONFIG}" in 230*/*) 231 . "${KCONFIG_CONFIG}" 232 ;; 233*) 234 # Force using a file from the current directory 235 . "./${KCONFIG_CONFIG}" 236esac 237 238# Update version 239info GEN .version 240if [ -r .version ]; then 241 VERSION=$(expr 0$(cat .version) + 1) 242 echo $VERSION > .version 243else 244 rm -f .version 245 echo 1 > .version 246fi; 247 248# final build of init/ 249${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}" 250 251archive_builtin 252 253#link vmlinux.o 254info LD vmlinux.o 255modpost_link vmlinux.o 256 257# modpost vmlinux.o to check for section mismatches 258${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o 259 260kallsymso="" 261kallsyms_vmlinux="" 262if [ -n "${CONFIG_KALLSYMS}" ]; then 263 264 # kallsyms support 265 # Generate section listing all symbols and add it into vmlinux 266 # It's a three step process: 267 # 1) Link .tmp_vmlinux1 so it has all symbols and sections, 268 # but __kallsyms is empty. 269 # Running kallsyms on that gives us .tmp_kallsyms1.o with 270 # the right size 271 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of 272 # the right size, but due to the added section, some 273 # addresses have shifted. 274 # From here, we generate a correct .tmp_kallsyms2.o 275 # 3) That link may have expanded the kernel image enough that 276 # more linker branch stubs / trampolines had to be added, which 277 # introduces new names, which further expands kallsyms. Do another 278 # pass if that is the case. In theory it's possible this results 279 # in even more stubs, but unlikely. 280 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around 281 # other bugs. 282 # 4) The correct ${kallsymso} is linked into the final vmlinux. 283 # 284 # a) Verify that the System.map from vmlinux matches the map from 285 # ${kallsymso}. 286 287 kallsymso=.tmp_kallsyms2.o 288 kallsyms_vmlinux=.tmp_vmlinux2 289 290 # step 1 291 vmlinux_link "" .tmp_vmlinux1 292 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o 293 294 # step 2 295 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2 296 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o 297 298 # step 3 299 size1=$(stat -c "%s" .tmp_kallsyms1.o) 300 size2=$(stat -c "%s" .tmp_kallsyms2.o) 301 302 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then 303 kallsymso=.tmp_kallsyms3.o 304 kallsyms_vmlinux=.tmp_vmlinux3 305 306 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3 307 308 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o 309 fi 310fi 311 312info LD vmlinux 313vmlinux_link "${kallsymso}" vmlinux 314 315if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then 316 info SORTEX vmlinux 317 sortextable vmlinux 318fi 319 320info SYSMAP System.map 321mksysmap vmlinux System.map 322 323# step a (see comment above) 324if [ -n "${CONFIG_KALLSYMS}" ]; then 325 mksysmap ${kallsyms_vmlinux} .tmp_System.map 326 327 if ! cmp -s System.map .tmp_System.map; then 328 echo >&2 Inconsistent kallsyms data 329 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround 330 exit 1 331 fi 332fi 333