1#!/bin/sh 2# 3# link vmlinux 4# 5# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and 6# $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories 7# in the kernel tree, others are specified in arch/$(ARCH)/Makefile. 8# Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first. 9# 10# vmlinux 11# ^ 12# | 13# +-< $(KBUILD_VMLINUX_INIT) 14# | +--< init/version.o + more 15# | 16# +--< $(KBUILD_VMLINUX_MAIN) 17# | +--< drivers/built-in.o mm/built-in.o + more 18# | 19# +-< ${kallsymso} (see description in KALLSYMS section) 20# 21# vmlinux version (uname -v) cannot be updated during normal 22# descending-into-subdirs phase since we do not yet know if we need to 23# update vmlinux. 24# Therefore this step is delayed until just before final link of vmlinux. 25# 26# System.map is generated to document addresses of all kernel symbols 27 28# Error out on error 29set -e 30 31# Nice output in kbuild format 32# Will be supressed by "make -s" 33info() 34{ 35 if [ "${quiet}" != "silent_" ]; then 36 printf " %-7s %s\n" ${1} ${2} 37 fi 38} 39 40# Thin archive build here makes a final archive with 41# symbol table and indexes from vmlinux objects, which can be 42# used as input to linker. 43# 44# Traditional incremental style of link does not require this step 45# 46# built-in.o output file 47# 48archive_builtin() 49{ 50 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 51 info AR built-in.o 52 rm -f built-in.o; 53 ${AR} rcsT${KBUILD_ARFLAGS} built-in.o \ 54 ${KBUILD_VMLINUX_INIT} \ 55 ${KBUILD_VMLINUX_MAIN} 56 57 if [ -n "${CONFIG_LTO_CLANG}" ]; then 58 mv -f built-in.o built-in.o.tmp 59 ${LLVM_AR} rcsT${KBUILD_ARFLAGS} built-in.o $(${AR} t built-in.o.tmp) 60 rm -f built-in.o.tmp 61 fi 62 fi 63} 64 65# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into 66# .tmp_symversions 67modversions() 68{ 69 if [ -z "${CONFIG_LTO_CLANG}" ]; then 70 return 71 fi 72 73 if [ -z "${CONFIG_MODVERSIONS}" ]; then 74 return 75 fi 76 77 rm -f .tmp_symversions 78 79 for a in built-in.o ${KBUILD_VMLINUX_LIBS}; do 80 for o in $(${AR} t $a); do 81 if [ -f ${o}.symversions ]; then 82 cat ${o}.symversions >> .tmp_symversions 83 fi 84 done 85 done 86 87 echo "-T .tmp_symversions" 88} 89 90# Link of vmlinux.o used for section mismatch analysis 91# ${1} output file 92modpost_link() 93{ 94 local objects 95 96 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 97 objects="--whole-archive built-in.o" 98 else 99 objects="${KBUILD_VMLINUX_INIT} \ 100 --start-group \ 101 ${KBUILD_VMLINUX_MAIN} \ 102 --end-group" 103 fi 104 105 if [ -n "${CONFIG_LTO_CLANG}" ]; then 106 # This might take a while, so indicate that we're doing 107 # an LTO link 108 info LTO vmlinux.o 109 else 110 info LD vmlinux.o 111 fi 112 113 ${LD} ${LDFLAGS} -r -o ${1} $(modversions) ${objects} 114} 115 116# If CONFIG_LTO_CLANG is selected, we postpone running recordmcount until 117# we have compiled LLVM IR to an object file. 118recordmcount() 119{ 120 if [ -z "${CONFIG_LTO_CLANG}" ]; then 121 return 122 fi 123 124 if [ -n "${CONFIG_FTRACE_MCOUNT_RECORD}" ]; then 125 scripts/recordmcount ${RECORDMCOUNT_FLAGS} $* 126 fi 127} 128 129# Link of vmlinux 130# ${1} - optional extra .o files 131# ${2} - output file 132vmlinux_link() 133{ 134 local lds="${objtree}/${KBUILD_LDS}" 135 local objects 136 137 if [ "${SRCARCH}" != "um" ]; then 138 local ld=${LD} 139 local ldflags="${LDFLAGS} ${LDFLAGS_vmlinux}" 140 141 if [ -n "${LDFINAL_vmlinux}" ]; then 142 ld=${LDFINAL_vmlinux} 143 ldflags="${LDFLAGS_FINAL_vmlinux} ${LDFLAGS_vmlinux}" 144 fi 145 146 if [[ -n "${CONFIG_THIN_ARCHIVES}" && -z "${CONFIG_LTO_CLANG}" ]]; then 147 objects="--whole-archive built-in.o ${1}" 148 else 149 objects="${KBUILD_VMLINUX_INIT} \ 150 --start-group \ 151 ${KBUILD_VMLINUX_MAIN} \ 152 --end-group \ 153 ${1}" 154 fi 155 156 ${ld} ${ldflags} -o ${2} -T ${lds} ${objects} 157 else 158 if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then 159 objects="-Wl,--whole-archive built-in.o ${1}" 160 else 161 objects="${KBUILD_VMLINUX_INIT} \ 162 -Wl,--start-group \ 163 ${KBUILD_VMLINUX_MAIN} \ 164 -Wl,--end-group \ 165 ${1}" 166 fi 167 168 ${CC} ${CFLAGS_vmlinux} -o ${2} \ 169 -Wl,-T,${lds} \ 170 ${objects} \ 171 -lutil -lrt -lpthread 172 rm -f linux 173 fi 174} 175 176# Create ${2} .o file with all symbols from the ${1} object file 177kallsyms() 178{ 179 info KSYM ${2} 180 local kallsymopt; 181 182 if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then 183 kallsymopt="${kallsymopt} --symbol-prefix=_" 184 fi 185 186 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then 187 kallsymopt="${kallsymopt} --all-symbols" 188 fi 189 190 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then 191 kallsymopt="${kallsymopt} --absolute-percpu" 192 fi 193 194 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then 195 kallsymopt="${kallsymopt} --base-relative" 196 fi 197 198 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ 199 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" 200 201 local afile="`basename ${2} .o`.S" 202 203 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile} 204 ${CC} ${aflags} -c -o ${2} ${afile} 205} 206 207# Create map file with all symbols from ${1} 208# See mksymap for additional details 209mksysmap() 210{ 211 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} 212} 213 214sortextable() 215{ 216 ${objtree}/scripts/sortextable ${1} 217} 218 219# Delete output files in case of error 220cleanup() 221{ 222 rm -f .old_version 223 rm -f .tmp_System.map 224 rm -f .tmp_kallsyms* 225 rm -f .tmp_version 226 rm -f .tmp_symversions 227 rm -f .tmp_vmlinux* 228 rm -f built-in.o 229 rm -f System.map 230 rm -f vmlinux 231 rm -f vmlinux.o 232} 233 234on_exit() 235{ 236 if [ $? -ne 0 ]; then 237 cleanup 238 fi 239} 240trap on_exit EXIT 241 242on_signals() 243{ 244 exit 1 245} 246trap on_signals HUP INT QUIT TERM 247 248# 249# 250# Use "make V=1" to debug this script 251case "${KBUILD_VERBOSE}" in 252*1*) 253 set -x 254 ;; 255esac 256 257if [ "$1" = "clean" ]; then 258 cleanup 259 exit 0 260fi 261 262# We need access to CONFIG_ symbols 263case "${KCONFIG_CONFIG}" in 264*/*) 265 . "${KCONFIG_CONFIG}" 266 ;; 267*) 268 # Force using a file from the current directory 269 . "./${KCONFIG_CONFIG}" 270esac 271 272# Update version 273info GEN .version 274if [ ! -r .version ]; then 275 rm -f .version; 276 echo 1 >.version; 277else 278 mv .version .old_version; 279 expr 0$(cat .old_version) + 1 >.version; 280fi; 281 282archive_builtin 283 284#link vmlinux.o 285modpost_link vmlinux.o 286 287# modpost vmlinux.o to check for section mismatches 288${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o 289 290# final build of init/ 291${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}" 292 293if [ -n "${CONFIG_LTO_CLANG}" ]; then 294 # Re-use vmlinux.o, so we can avoid the slow LTO link step in 295 # vmlinux_link 296 KBUILD_VMLINUX_INIT= 297 KBUILD_VMLINUX_MAIN=vmlinux.o 298 299 # Call recordmcount if needed 300 recordmcount vmlinux.o 301fi 302 303kallsymso="" 304kallsyms_vmlinux="" 305if [ -n "${CONFIG_KALLSYMS}" ]; then 306 307 # kallsyms support 308 # Generate section listing all symbols and add it into vmlinux 309 # It's a three step process: 310 # 1) Link .tmp_vmlinux1 so it has all symbols and sections, 311 # but __kallsyms is empty. 312 # Running kallsyms on that gives us .tmp_kallsyms1.o with 313 # the right size 314 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of 315 # the right size, but due to the added section, some 316 # addresses have shifted. 317 # From here, we generate a correct .tmp_kallsyms2.o 318 # 2a) We may use an extra pass as this has been necessary to 319 # woraround some alignment related bugs. 320 # KALLSYMS_EXTRA_PASS=1 is used to trigger this. 321 # 3) The correct ${kallsymso} is linked into the final vmlinux. 322 # 323 # a) Verify that the System.map from vmlinux matches the map from 324 # ${kallsymso}. 325 326 kallsymso=.tmp_kallsyms2.o 327 kallsyms_vmlinux=.tmp_vmlinux2 328 329 # step 1 330 vmlinux_link "" .tmp_vmlinux1 331 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o 332 333 # step 2 334 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2 335 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o 336 337 # step 2a 338 if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then 339 kallsymso=.tmp_kallsyms3.o 340 kallsyms_vmlinux=.tmp_vmlinux3 341 342 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3 343 344 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o 345 fi 346fi 347 348info LD vmlinux 349vmlinux_link "${kallsymso}" vmlinux 350 351if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then 352 info SORTEX vmlinux 353 sortextable vmlinux 354fi 355 356info SYSMAP System.map 357mksysmap vmlinux System.map 358 359# step a (see comment above) 360if [ -n "${CONFIG_KALLSYMS}" ]; then 361 mksysmap ${kallsyms_vmlinux} .tmp_System.map 362 363 if ! cmp -s System.map .tmp_System.map; then 364 echo >&2 Inconsistent kallsyms data 365 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround 366 exit 1 367 fi 368fi 369 370# We made a new kernel - delete old version file 371rm -f .old_version 372