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Diffstat (limited to '')
-rwxr-xr-x | scripts/link-vmlinux.sh | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh new file mode 100755 index 000000000..c8cf45362 --- /dev/null +++ b/scripts/link-vmlinux.sh @@ -0,0 +1,301 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# link vmlinux +# +# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and +# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.a files +# from top-level directories in the kernel tree, others are specified in +# arch/$(ARCH)/Makefile. Ordering when linking is important, and +# $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives +# which are linked conditionally (not within --whole-archive), and do not +# require symbol indexes added. +# +# vmlinux +# ^ +# | +# +-< $(KBUILD_VMLINUX_INIT) +# | +--< init/version.o + more +# | +# +--< $(KBUILD_VMLINUX_MAIN) +# | +--< drivers/built-in.a mm/built-in.a + more +# | +# +--< $(KBUILD_VMLINUX_LIBS) +# | +--< lib/lib.a + more +# | +# +-< ${kallsymso} (see description in KALLSYMS section) +# +# vmlinux version (uname -v) cannot be updated during normal +# descending-into-subdirs phase since we do not yet know if we need to +# update vmlinux. +# Therefore this step is delayed until just before final link of vmlinux. +# +# System.map is generated to document addresses of all kernel symbols + +# Error out on error +set -e + +# Nice output in kbuild format +# Will be supressed by "make -s" +info() +{ + if [ "${quiet}" != "silent_" ]; then + printf " %-7s %s\n" ${1} ${2} + fi +} + +# Thin archive build here makes a final archive with symbol table and indexes +# from vmlinux objects INIT and MAIN, which can be used as input to linker. +# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes +# added. +# +# Traditional incremental style of link does not require this step +# +# built-in.a output file +# +archive_builtin() +{ + info AR built-in.a + rm -f built-in.a; + ${AR} rcsTP${KBUILD_ARFLAGS} built-in.a \ + ${KBUILD_VMLINUX_INIT} \ + ${KBUILD_VMLINUX_MAIN} +} + +# Link of vmlinux.o used for section mismatch analysis +# ${1} output file +modpost_link() +{ + local objects + + objects="--whole-archive \ + built-in.a \ + --no-whole-archive \ + --start-group \ + ${KBUILD_VMLINUX_LIBS} \ + --end-group" + + ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects} +} + +# Link of vmlinux +# ${1} - optional extra .o files +# ${2} - output file +vmlinux_link() +{ + local lds="${objtree}/${KBUILD_LDS}" + local objects + + if [ "${SRCARCH}" != "um" ]; then + objects="--whole-archive \ + built-in.a \ + --no-whole-archive \ + --start-group \ + ${KBUILD_VMLINUX_LIBS} \ + --end-group \ + ${1}" + + ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \ + -T ${lds} ${objects} + else + objects="-Wl,--whole-archive \ + built-in.a \ + -Wl,--no-whole-archive \ + -Wl,--start-group \ + ${KBUILD_VMLINUX_LIBS} \ + -Wl,--end-group \ + ${1}" + + ${CC} ${CFLAGS_vmlinux} -o ${2} \ + -Wl,-T,${lds} \ + ${objects} \ + -lutil -lrt -lpthread + rm -f linux + fi +} + + +# Create ${2} .o file with all symbols from the ${1} object file +kallsyms() +{ + info KSYM ${2} + local kallsymopt; + + if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then + kallsymopt="${kallsymopt} --all-symbols" + fi + + if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then + kallsymopt="${kallsymopt} --absolute-percpu" + fi + + if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then + kallsymopt="${kallsymopt} --base-relative" + fi + + local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ + ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" + + local afile="`basename ${2} .o`.S" + + ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile} + ${CC} ${aflags} -c -o ${2} ${afile} +} + +# Create map file with all symbols from ${1} +# See mksymap for additional details +mksysmap() +{ + ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} +} + +sortextable() +{ + ${objtree}/scripts/sortextable ${1} +} + +# Delete output files in case of error +cleanup() +{ + rm -f .tmp_System.map + rm -f .tmp_kallsyms* + rm -f .tmp_vmlinux* + rm -f built-in.a + rm -f System.map + rm -f vmlinux + rm -f vmlinux.o +} + +on_exit() +{ + if [ $? -ne 0 ]; then + cleanup + fi +} +trap on_exit EXIT + +on_signals() +{ + exit 1 +} +trap on_signals HUP INT QUIT TERM + +# +# +# Use "make V=1" to debug this script +case "${KBUILD_VERBOSE}" in +*1*) + set -x + ;; +esac + +if [ "$1" = "clean" ]; then + cleanup + exit 0 +fi + +# We need access to CONFIG_ symbols +case "${KCONFIG_CONFIG}" in +*/*) + . "${KCONFIG_CONFIG}" + ;; +*) + # Force using a file from the current directory + . "./${KCONFIG_CONFIG}" +esac + +# Update version +info GEN .version +if [ -r .version ]; then + VERSION=$(expr 0$(cat .version) + 1) + echo $VERSION > .version +else + rm -f .version + echo 1 > .version +fi; + +# final build of init/ +${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init + +archive_builtin + +#link vmlinux.o +info LD vmlinux.o +modpost_link vmlinux.o + +# modpost vmlinux.o to check for section mismatches +${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o + +kallsymso="" +kallsyms_vmlinux="" +if [ -n "${CONFIG_KALLSYMS}" ]; then + + # kallsyms support + # Generate section listing all symbols and add it into vmlinux + # It's a three step process: + # 1) Link .tmp_vmlinux1 so it has all symbols and sections, + # but __kallsyms is empty. + # Running kallsyms on that gives us .tmp_kallsyms1.o with + # the right size + # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of + # the right size, but due to the added section, some + # addresses have shifted. + # From here, we generate a correct .tmp_kallsyms2.o + # 3) That link may have expanded the kernel image enough that + # more linker branch stubs / trampolines had to be added, which + # introduces new names, which further expands kallsyms. Do another + # pass if that is the case. In theory it's possible this results + # in even more stubs, but unlikely. + # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around + # other bugs. + # 4) The correct ${kallsymso} is linked into the final vmlinux. + # + # a) Verify that the System.map from vmlinux matches the map from + # ${kallsymso}. + + kallsymso=.tmp_kallsyms2.o + kallsyms_vmlinux=.tmp_vmlinux2 + + # step 1 + vmlinux_link "" .tmp_vmlinux1 + kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o + + # step 2 + vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2 + kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o + + # step 3 + size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o) + size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o) + + if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then + kallsymso=.tmp_kallsyms3.o + kallsyms_vmlinux=.tmp_vmlinux3 + + vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3 + + kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o + fi +fi + +info LD vmlinux +vmlinux_link "${kallsymso}" vmlinux + +if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then + info SORTEX vmlinux + sortextable vmlinux +fi + +info SYSMAP System.map +mksysmap vmlinux System.map + +# step a (see comment above) +if [ -n "${CONFIG_KALLSYMS}" ]; then + mksysmap ${kallsyms_vmlinux} .tmp_System.map + + if ! cmp -s System.map .tmp_System.map; then + echo >&2 Inconsistent kallsyms data + echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround + exit 1 + fi +fi |