| #!/bin/sh |
| # SPDX-License-Identifier: GPL-2.0 |
| # |
| # link vmlinux |
| # |
| # vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_OBJS) 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. |
| # $(KBUILD_VMLINUX_LIBS) are archives which are linked conditionally |
| # (not within --whole-archive), and do not require symbol indexes added. |
| # |
| # vmlinux |
| # ^ |
| # | |
| # +--< $(KBUILD_VMLINUX_OBJS) |
| # | +--< init/built-in.a 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 |
| } |
| |
| # Link of vmlinux.o used for section mismatch analysis |
| # ${1} output file |
| modpost_link() |
| { |
| local objects |
| |
| objects="--whole-archive \ |
| ${KBUILD_VMLINUX_OBJS} \ |
| --no-whole-archive \ |
| --start-group \ |
| ${KBUILD_VMLINUX_LIBS} \ |
| --end-group" |
| |
| ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects} |
| } |
| |
| # Link of vmlinux |
| # ${1} - output file |
| # ${2}, ${3}, ... - optional extra .o files |
| vmlinux_link() |
| { |
| local lds="${objtree}/${KBUILD_LDS}" |
| local output=${1} |
| local objects |
| local strip_debug |
| |
| info LD ${output} |
| |
| # skip output file argument |
| shift |
| |
| # The kallsyms linking does not need debug symbols included. |
| if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then |
| strip_debug=-Wl,--strip-debug |
| fi |
| |
| if [ "${SRCARCH}" != "um" ]; then |
| objects="--whole-archive \ |
| ${KBUILD_VMLINUX_OBJS} \ |
| --no-whole-archive \ |
| --start-group \ |
| ${KBUILD_VMLINUX_LIBS} \ |
| --end-group \ |
| ${@}" |
| |
| ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \ |
| ${strip_debug#-Wl,} \ |
| -o ${output} \ |
| -T ${lds} ${objects} |
| else |
| objects="-Wl,--whole-archive \ |
| ${KBUILD_VMLINUX_OBJS} \ |
| -Wl,--no-whole-archive \ |
| -Wl,--start-group \ |
| ${KBUILD_VMLINUX_LIBS} \ |
| -Wl,--end-group \ |
| ${@}" |
| |
| ${CC} ${CFLAGS_vmlinux} \ |
| ${strip_debug} \ |
| -o ${output} \ |
| -Wl,-T,${lds} \ |
| ${objects} \ |
| -lutil -lrt -lpthread |
| rm -f linux |
| fi |
| } |
| |
| # generate .BTF typeinfo from DWARF debuginfo |
| # ${1} - vmlinux image |
| # ${2} - file to dump raw BTF data into |
| gen_btf() |
| { |
| local pahole_ver |
| |
| if ! [ -x "$(command -v ${PAHOLE})" ]; then |
| echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available" |
| return 1 |
| fi |
| |
| pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/') |
| if [ "${pahole_ver}" -lt "113" ]; then |
| echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13" |
| return 1 |
| fi |
| |
| vmlinux_link ${1} |
| |
| info "BTF" ${2} |
| LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1} |
| |
| # Create ${2} 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} ${2} 2>/dev/null |
| # Change e_type to ET_REL so that it can be used to link final vmlinux. |
| # GNU ld 2.35+ and lld do not allow an ET_EXEC input. |
| if [ -n "${CONFIG_CPU_BIG_ENDIAN}" ]; then |
| et_rel='\0\1' |
| else |
| et_rel='\1\0' |
| fi |
| printf "${et_rel}" | dd of=${2} conv=notrunc bs=1 seek=16 status=none |
| } |
| |
| # 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} ${afile} |
| } |
| |
| # Perform one step in kallsyms generation, including temporary linking of |
| # vmlinux. |
| kallsyms_step() |
| { |
| kallsymso_prev=${kallsymso} |
| kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1} |
| kallsymso=${kallsyms_vmlinux}.o |
| |
| vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o} |
| kallsyms ${kallsyms_vmlinux} ${kallsymso} |
| } |
| |
| # 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 .btf.* |
| rm -f .tmp_System.map |
| rm -f .tmp_vmlinux* |
| 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 [ "$1" = "clean" ]; then |
| cleanup |
| exit 0 |
| fi |
| |
| # We need access to CONFIG_ symbols |
| . include/config/auto.conf |
| |
| # Update version |
| info GEN .version |
| if [ -r .version ]; then |
| VERSION=$(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 |
| |
| #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" MODPOST_VMLINUX=1 |
| |
| info MODINFO modules.builtin.modinfo |
| ${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo |
| |
| btf_vmlinux_bin_o="" |
| if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then |
| btf_vmlinux_bin_o=.btf.vmlinux.bin.o |
| if ! gen_btf .tmp_vmlinux.btf $btf_vmlinux_bin_o ; then |
| echo >&2 "Failed to generate BTF for vmlinux" |
| echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF" |
| exit 1 |
| fi |
| fi |
| |
| kallsymso="" |
| kallsymso_prev="" |
| kallsyms_vmlinux="" |
| if [ -n "${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 |
| # ${kallsymso}. |
| |
| kallsyms_step 1 |
| kallsyms_step 2 |
| |
| # step 3 |
| size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso_prev}) |
| size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" ${kallsymso}) |
| |
| if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then |
| kallsyms_step 3 |
| fi |
| fi |
| |
| vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o} |
| |
| if [ -n "${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 |