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 95# Create ${2} .o file with all symbols from the ${1} object file 96kallsyms() 97{ 98 info KSYM ${2} 99 local kallsymopt; 100 101 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then 102 kallsymopt="${kallsymopt} --all-symbols" 103 fi 104 105 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then 106 kallsymopt="${kallsymopt} --absolute-percpu" 107 fi 108 109 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then 110 kallsymopt="${kallsymopt} --base-relative" 111 fi 112 113 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ 114 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" 115 116 local afile="`basename ${2} .o`.S" 117 118 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile} 119 ${CC} ${aflags} -c -o ${2} ${afile} 120} 121 122# Create map file with all symbols from ${1} 123# See mksymap for additional details 124mksysmap() 125{ 126 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} 127} 128 129sortextable() 130{ 131 ${objtree}/scripts/sortextable ${1} 132} 133 134# Delete output files in case of error 135cleanup() 136{ 137 rm -f .tmp_System.map 138 rm -f .tmp_kallsyms* 139 rm -f .tmp_vmlinux* 140 rm -f System.map 141 rm -f vmlinux 142 rm -f vmlinux.o 143} 144 145on_exit() 146{ 147 if [ $? -ne 0 ]; then 148 cleanup 149 fi 150} 151trap on_exit EXIT 152 153on_signals() 154{ 155 exit 1 156} 157trap on_signals HUP INT QUIT TERM 158 159# 160# 161# Use "make V=1" to debug this script 162case "${KBUILD_VERBOSE}" in 163*1*) 164 set -x 165 ;; 166esac 167 168if [ "$1" = "clean" ]; then 169 cleanup 170 exit 0 171fi 172 173# We need access to CONFIG_ symbols 174case "${KCONFIG_CONFIG}" in 175*/*) 176 . "${KCONFIG_CONFIG}" 177 ;; 178*) 179 # Force using a file from the current directory 180 . "./${KCONFIG_CONFIG}" 181esac 182 183# Update version 184info GEN .version 185if [ -r .version ]; then 186 VERSION=$(expr 0$(cat .version) + 1) 187 echo $VERSION > .version 188else 189 rm -f .version 190 echo 1 > .version 191fi; 192 193# final build of init/ 194${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init 195 196#link vmlinux.o 197info LD vmlinux.o 198modpost_link vmlinux.o 199 200# modpost vmlinux.o to check for section mismatches 201${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o 202 203kallsymso="" 204kallsyms_vmlinux="" 205if [ -n "${CONFIG_KALLSYMS}" ]; then 206 207 # kallsyms support 208 # Generate section listing all symbols and add it into vmlinux 209 # It's a three step process: 210 # 1) Link .tmp_vmlinux1 so it has all symbols and sections, 211 # but __kallsyms is empty. 212 # Running kallsyms on that gives us .tmp_kallsyms1.o with 213 # the right size 214 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of 215 # the right size, but due to the added section, some 216 # addresses have shifted. 217 # From here, we generate a correct .tmp_kallsyms2.o 218 # 3) That link may have expanded the kernel image enough that 219 # more linker branch stubs / trampolines had to be added, which 220 # introduces new names, which further expands kallsyms. Do another 221 # pass if that is the case. In theory it's possible this results 222 # in even more stubs, but unlikely. 223 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around 224 # other bugs. 225 # 4) The correct ${kallsymso} is linked into the final vmlinux. 226 # 227 # a) Verify that the System.map from vmlinux matches the map from 228 # ${kallsymso}. 229 230 kallsymso=.tmp_kallsyms2.o 231 kallsyms_vmlinux=.tmp_vmlinux2 232 233 # step 1 234 vmlinux_link "" .tmp_vmlinux1 235 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o 236 237 # step 2 238 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2 239 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o 240 241 # step 3 242 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o) 243 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o) 244 245 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then 246 kallsymso=.tmp_kallsyms3.o 247 kallsyms_vmlinux=.tmp_vmlinux3 248 249 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3 250 251 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o 252 fi 253fi 254 255info LD vmlinux 256vmlinux_link "${kallsymso}" vmlinux 257 258if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then 259 info SORTEX vmlinux 260 sortextable vmlinux 261fi 262 263info SYSMAP System.map 264mksysmap vmlinux System.map 265 266# step a (see comment above) 267if [ -n "${CONFIG_KALLSYMS}" ]; then 268 mksysmap ${kallsyms_vmlinux} .tmp_System.map 269 270 if ! cmp -s System.map .tmp_System.map; then 271 echo >&2 Inconsistent kallsyms data 272 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround 273 exit 1 274 fi 275fi 276