diff options
Diffstat (limited to 'scripts/link-vmlinux.sh')
| -rwxr-xr-x[-rw-r--r--] | scripts/link-vmlinux.sh | 338 |
1 files changed, 214 insertions, 124 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 014994936b1c..4ab44c73da4d 100644..100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -1,20 +1,20 @@ #!/bin/sh +# SPDX-License-Identifier: GPL-2.0 # # link vmlinux # -# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and -# $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories -# in the kernel tree, others are specified in arch/$(ARCH)/Makefile. -# Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first. +# vmlinux is linked from the objects in vmlinux.a and $(KBUILD_VMLINUX_LIBS). +# vmlinux.a contains objects that are linked unconditionally. +# $(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 +# +--< vmlinux.a # | -# +--< $(KBUILD_VMLINUX_MAIN) -# | +--< drivers/built-in.o mm/built-in.o + more +# +--< $(KBUILD_VMLINUX_LIBS) +# | +--< lib/lib.a + more # | # +-< ${kallsymso} (see description in KALLSYMS section) # @@ -28,96 +28,163 @@ # Error out on error set -e +LD="$1" +KBUILD_LDFLAGS="$2" +LDFLAGS_vmlinux="$3" +VMLINUX="$4" + +is_enabled() { + grep -q "^$1=y" include/config/auto.conf +} + # Nice output in kbuild format # Will be supressed by "make -s" info() { - if [ "${quiet}" != "silent_" ]; then - printf " %-7s %s\n" ${1} ${2} - fi -} - -# Link of vmlinux.o used for section mismatch analysis -# ${1} output file -modpost_link() -{ - ${LD} ${LDFLAGS} -r -o ${1} ${KBUILD_VMLINUX_INIT} \ - --start-group ${KBUILD_VMLINUX_MAIN} --end-group + printf " %-7s %s\n" "${1}" "${2}" } # Link of vmlinux -# ${1} - optional extra .o files -# ${2} - output file +# ${1} - output file vmlinux_link() { - local lds="${objtree}/${KBUILD_LDS}" + local output=${1} + local objs + local libs + local ld + local ldflags + local ldlibs + + info LD ${output} + + # skip output file argument + shift + + if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT || + is_enabled CONFIG_KLP_BUILD; then + # Use vmlinux.o instead of performing the slow LTO link again. + objs=vmlinux.o + libs= + else + objs=vmlinux.a + libs="${KBUILD_VMLINUX_LIBS}" + fi + + if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then + objs="${objs} .builtin-dtbs.o" + fi - if [ "${SRCARCH}" != "um" ]; then - ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \ - -T ${lds} ${KBUILD_VMLINUX_INIT} \ - --start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1} + objs="${objs} .vmlinux.export.o" + objs="${objs} init/version-timestamp.o" + + if [ "${SRCARCH}" = "um" ]; then + wl=-Wl, + ld="${CC}" + ldflags="${CFLAGS_vmlinux}" + ldlibs="-lutil -lrt -lpthread" else - ${CC} ${CFLAGS_vmlinux} -o ${2} \ - -Wl,-T,${lds} ${KBUILD_VMLINUX_INIT} \ - -Wl,--start-group \ - ${KBUILD_VMLINUX_MAIN} \ - -Wl,--end-group \ - -lutil ${1} - rm -f linux + wl= + ld="${LD}" + ldflags="${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux}" + ldlibs= fi + + ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}" + + # The kallsyms linking does not need debug symbols included. + if [ -n "${strip_debug}" ] ; then + ldflags="${ldflags} ${wl}--strip-debug" + fi + + if [ -n "${generate_map}" ]; then + ldflags="${ldflags} ${wl}-Map=vmlinux.map" + fi + + ${ld} ${ldflags} -o ${output} \ + ${wl}--whole-archive ${objs} ${wl}--no-whole-archive \ + ${wl}--start-group ${libs} ${wl}--end-group \ + ${kallsymso} ${btf_vmlinux_bin_o} ${arch_vmlinux_o} ${ldlibs} } +# generate .BTF typeinfo from DWARF debuginfo +# ${1} - vmlinux image +gen_btf() +{ + local btf_data=${1}.btf.o + + info BTF "${btf_data}" + LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1} + + # Create ${btf_data} which contains just .BTF section but no symbols. Add + # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all + # deletes all symbols including __start_BTF and __stop_BTF, which will + # be redefined in the linker script. Add 2>/dev/null to suppress GNU + # objcopy warnings: "empty loadable segment detected at ..." + ${OBJCOPY} --only-section=.BTF --set-section-flags .BTF=alloc,readonly \ + --strip-all ${1} "${btf_data}" 2>/dev/null + # Change e_type to ET_REL so that it can be used to link final vmlinux. + # GNU ld 2.35+ and lld do not allow an ET_EXEC input. + if is_enabled CONFIG_CPU_BIG_ENDIAN; then + et_rel='\0\1' + else + et_rel='\1\0' + fi + printf "${et_rel}" | dd of="${btf_data}" conv=notrunc bs=1 seek=16 status=none -# Create ${2} .o file with all symbols from the ${1} object file + btf_vmlinux_bin_o=${btf_data} +} + +# Create ${2}.o file with all symbols from the ${1} object file kallsyms() { - info KSYM ${2} local kallsymopt; - if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then - kallsymopt="${kallsymopt} --symbol-prefix=_" - fi - - if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then + if is_enabled CONFIG_KALLSYMS_ALL; then kallsymopt="${kallsymopt} --all-symbols" fi - local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ - ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" + info KSYMS "${2}.S" + scripts/kallsyms ${kallsymopt} "${1}" > "${2}.S" + + info AS "${2}.o" + ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \ + ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} -c -o "${2}.o" "${2}.S" - ${NM} -n ${1} | \ - scripts/kallsyms ${kallsymopt} | \ - ${CC} ${aflags} -c -o ${2} -x assembler-with-cpp - + kallsymso=${2}.o +} + +# Perform kallsyms for the given temporary vmlinux. +sysmap_and_kallsyms() +{ + mksysmap "${1}" "${1}.syms" + kallsyms "${1}.syms" "${1}.kallsyms" + + kallsyms_sysmap=${1}.syms } # Create map file with all symbols from ${1} # See mksymap for additional details mksysmap() { - ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} + info NM ${2} + ${NM} -n "${1}" | sed -f "${srctree}/scripts/mksysmap" > "${2}" } -sortextable() +sorttable() { - ${objtree}/scripts/sortextable ${1} + ${NM} -S ${1} > .tmp_vmlinux.nm-sort + ${objtree}/scripts/sorttable -s .tmp_vmlinux.nm-sort ${1} } -# Delete output files in case of error -trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR cleanup() { - rm -f .old_version - rm -f .tmp_System.map - rm -f .tmp_kallsyms* - rm -f .tmp_version - rm -f .tmp_vmlinux* + rm -f .btf.* + rm -f .tmp_vmlinux.nm-sort rm -f System.map rm -f vmlinux - rm -f vmlinux.o + rm -f vmlinux.map } -# -# # Use "make V=1" to debug this script case "${KBUILD_VERBOSE}" in *1*) @@ -130,103 +197,126 @@ if [ "$1" = "clean" ]; then exit 0 fi -# We need access to CONFIG_ symbols -case "${KCONFIG_CONFIG}" in -*/*) - . "${KCONFIG_CONFIG}" +${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init init/version-timestamp.o + +arch_vmlinux_o= +if is_enabled CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX; then + arch_vmlinux_o=arch/${SRCARCH}/tools/vmlinux.arch.o +fi + +btf_vmlinux_bin_o= +kallsymso= +strip_debug= +generate_map= + +# Use "make UT=1" to trigger warnings on unused tracepoints +case "${WARN_ON_UNUSED_TRACEPOINTS}" in +*1*) + ${objtree}/scripts/tracepoint-update vmlinux.o ;; -*) - # Force using a file from the current directory - . "./${KCONFIG_CONFIG}" esac -#link vmlinux.o -info LD vmlinux.o -modpost_link vmlinux.o +if is_enabled CONFIG_KALLSYMS; then + true > .tmp_vmlinux0.syms + kallsyms .tmp_vmlinux0.syms .tmp_vmlinux0.kallsyms +fi + +if is_enabled CONFIG_KALLSYMS || is_enabled CONFIG_DEBUG_INFO_BTF; then -# modpost vmlinux.o to check for section mismatches -${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o + # The kallsyms linking does not need debug symbols, but the BTF does. + if ! is_enabled CONFIG_DEBUG_INFO_BTF; then + strip_debug=1 + fi -# Update version -info GEN .version -if [ ! -r .version ]; then - rm -f .version; - echo 1 >.version; -else - mv .version .old_version; - expr 0$(cat .old_version) + 1 >.version; -fi; + vmlinux_link .tmp_vmlinux1 +fi -# final build of init/ -${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init +if is_enabled CONFIG_DEBUG_INFO_BTF; then + if ! gen_btf .tmp_vmlinux1; then + echo >&2 "Failed to generate BTF for vmlinux" + echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF" + exit 1 + fi +fi -kallsymso="" -kallsyms_vmlinux="" -if [ -n "${CONFIG_KALLSYMS}" ]; then +if is_enabled 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 + # It's a four step process: + # 0) Generate a dummy __kallsyms with empty symbol list. + # 1) Link .tmp_vmlinux1.kallsyms so it has all symbols and sections, + # with a dummy __kallsyms. + # Running kallsyms on that gives us .tmp_vmlinux1.kallsyms.o with # the right size - # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of + # 2) Link .tmp_vmlinux2.kallsyms 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 - # 2a) We may use an extra pass as this has been necessary to - # woraround some alignment related bugs. - # KALLSYMS_EXTRA_PASS=1 is used to trigger this. - # 3) The correct ${kallsymso} is linked into the final vmlinux. + # From here, we generate a correct .tmp_vmlinux2.kallsyms.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 # ${kallsymso}. - kallsymso=.tmp_kallsyms2.o - kallsyms_vmlinux=.tmp_vmlinux2 + # The kallsyms linking does not need debug symbols included. + strip_debug=1 - # step 1 - vmlinux_link "" .tmp_vmlinux1 - kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o + sysmap_and_kallsyms .tmp_vmlinux1 + size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso}) - # step 2 - vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2 - kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o + vmlinux_link .tmp_vmlinux2 + sysmap_and_kallsyms .tmp_vmlinux2 + size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso}) - # step 2a - if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then - kallsymso=.tmp_kallsyms3.o - kallsyms_vmlinux=.tmp_vmlinux3 + if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then + vmlinux_link .tmp_vmlinux3 + sysmap_and_kallsyms .tmp_vmlinux3 + fi +fi - vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3 +strip_debug= - kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o - fi +if is_enabled CONFIG_VMLINUX_MAP; then + generate_map=1 fi -info LD vmlinux -vmlinux_link "${kallsymso}" vmlinux +vmlinux_link "${VMLINUX}" -if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then - info SORTEX vmlinux - sortextable vmlinux +# fill in BTF IDs +if is_enabled CONFIG_DEBUG_INFO_BTF; then + info BTFIDS "${VMLINUX}" + RESOLVE_BTFIDS_ARGS="" + if is_enabled CONFIG_WERROR; then + RESOLVE_BTFIDS_ARGS=" --fatal_warnings " + fi + ${RESOLVE_BTFIDS} ${RESOLVE_BTFIDS_ARGS} "${VMLINUX}" fi -info SYSMAP System.map -mksysmap vmlinux System.map +mksysmap "${VMLINUX}" System.map -# step a (see comment above) -if [ -n "${CONFIG_KALLSYMS}" ]; then - mksysmap ${kallsyms_vmlinux} .tmp_System.map +if is_enabled CONFIG_BUILDTIME_TABLE_SORT; then + info SORTTAB "${VMLINUX}" + if ! sorttable "${VMLINUX}"; then + echo >&2 Failed to sort kernel tables + exit 1 + fi +fi - if ! cmp -s System.map .tmp_System.map; then +# step a (see comment above) +if is_enabled CONFIG_KALLSYMS; then + if ! cmp -s System.map "${kallsyms_sysmap}"; then echo >&2 Inconsistent kallsyms data - echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround - cleanup + echo >&2 'Try "make KALLSYMS_EXTRA_PASS=1" as a workaround' exit 1 fi fi -# We made a new kernel - delete old version file -rm -f .old_version +# For fixdep +echo "${VMLINUX}: $0" > ".${VMLINUX}.d" |