android_kernel_sony_sdm845/scripts/link-vmlinux.sh
Andrii Nakryiko ed579eb7f4 UPSTREAM: kbuild: tolerate missing pahole when generating BTF
When BTF generation is enabled through CONFIG_DEBUG_INFO_BTF,
scripts/link-vmlinux.sh detects if pahole version is too old and
gracefully continues build process, skipping BTF generation build step.
But if pahole is not available, build will still fail. This patch adds
check for whether pahole exists at all and bails out gracefully, if not.

Cc: Alexei Starovoitov <ast@fb.com>
Reported-by: Yonghong Song <yhs@fb.com>
Fixes: e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")
Change-Id: I89e477f03aba8e16789b2a330469b2ac562df4d5
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
2026-05-15 17:58:04 +07:00

447 lines
11 KiB
Shell

#!/bin/sh
#
# 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
# ^
# |
# +-< $(KBUILD_VMLINUX_INIT)
# | +--< init/version.o + more
# |
# +--< $(KBUILD_VMLINUX_MAIN)
# | +--< drivers/built-in.o mm/built-in.o + 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, which can be
# used as input to linker.
#
# Traditional incremental style of link does not require this step
#
# built-in.o output file
#
archive_builtin()
{
if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
info AR built-in.o
rm -f built-in.o;
${AR} rcsT${KBUILD_ARFLAGS} built-in.o \
${KBUILD_VMLINUX_INIT} \
${KBUILD_VMLINUX_MAIN}
if [ -n "${CONFIG_LTO_CLANG}" ]; then
mv -f built-in.o built-in.o.tmp
${LLVM_AR} rcsT${KBUILD_ARFLAGS} built-in.o $(${AR} t built-in.o.tmp)
rm -f built-in.o.tmp
fi
fi
}
# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into
# .tmp_symversions
modversions()
{
if [ -z "${CONFIG_LTO_CLANG}" ]; then
return
fi
if [ -z "${CONFIG_MODVERSIONS}" ]; then
return
fi
rm -f .tmp_symversions
for a in built-in.o ${KBUILD_VMLINUX_LIBS}; do
for o in $(${AR} t $a); do
if [ -f ${o}.symversions ]; then
cat ${o}.symversions >> .tmp_symversions
fi
done
done
echo "-T .tmp_symversions"
}
# Link of vmlinux.o used for section mismatch analysis
# ${1} output file
modpost_link()
{
local objects
if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
objects="--whole-archive built-in.o"
else
objects="${KBUILD_VMLINUX_INIT} \
--start-group \
${KBUILD_VMLINUX_MAIN} \
--end-group"
fi
if [ -n "${CONFIG_LTO_CLANG}" ]; then
# This might take a while, so indicate that we're doing
# an LTO link
info LTO vmlinux.o
else
info LD vmlinux.o
fi
${LD} ${LDFLAGS} -r -o ${1} $(modversions) ${objects}
}
# If CONFIG_LTO_CLANG is selected, we postpone running recordmcount until
# we have compiled LLVM IR to an object file.
recordmcount()
{
if [ -z "${CONFIG_LTO_CLANG}" ]; then
return
fi
if [ -n "${CONFIG_FTRACE_MCOUNT_RECORD}" ]; then
scripts/recordmcount ${RECORDMCOUNT_FLAGS} $*
fi
}
# Link of vmlinux
# ${1} - optional extra .o files
# ${2} - output file
vmlinux_link()
{
local lds="${objtree}/${KBUILD_LDS}"
local objects
if [ "${SRCARCH}" != "um" ]; then
local ld=${LD}
local ldflags="${LDFLAGS} ${LDFLAGS_vmlinux}"
if [ -n "${LDFINAL_vmlinux}" ]; then
ld=${LDFINAL_vmlinux}
ldflags="${LDFLAGS_FINAL_vmlinux} ${LDFLAGS_vmlinux}"
fi
if [[ -n "${CONFIG_THIN_ARCHIVES}" && -z "${CONFIG_LTO_CLANG}" ]]; then
objects="--whole-archive built-in.o ${1}"
else
objects="${KBUILD_VMLINUX_INIT} \
--start-group \
${KBUILD_VMLINUX_MAIN} \
--end-group \
${1}"
fi
${ld} ${ldflags} -o ${2} -T ${lds} ${objects}
else
if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
objects="-Wl,--whole-archive built-in.o ${1}"
else
objects="${KBUILD_VMLINUX_INIT} \
-Wl,--start-group \
${KBUILD_VMLINUX_MAIN} \
-Wl,--end-group \
${1}"
fi
${CC} ${CFLAGS_vmlinux} -o ${2} \
-Wl,-T,${lds} \
${objects} \
-lutil -lrt -lpthread
rm -f linux
fi
}
# generate .BTF typeinfo from DWARF debuginfo
gen_btf()
{
local pahole_ver;
if ! [ -x "$(command -v ${PAHOLE})" ]; then
info "BTF" "${1}: pahole (${PAHOLE}) is not available"
return 0
fi
pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
if [ "${pahole_ver}" -lt "113" ]; then
info "BTF" "${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13"
exit 0
fi
info "BTF" ${1}
LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
}
# 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
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} 2>/dev/null | scripts/kallsyms ${kallsymopt} > ${afile}
${CC} ${aflags} -c -o ${2} ${afile}
}
# Generates ${2} .o file with RTIC MP's from the ${1} object file (vmlinux)
# ${3} the file name where the sizes of the RTIC MP structure are stored
# just in case, save copy of the RTIC mp to ${4}
# Note: RTIC_MPGEN has to be set if MPGen is available
rtic_mp()
{
# assume that RTIC_MP_O generation may fail
RTIC_MP_O=
local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
${RTIC_MPGEN} --objcopy="${OBJCOPY}" --objdump="${OBJDUMP}" \
--binpath='' --vmlinux=${1} --config=${KCONFIG_CONFIG} && \
cat rtic_mp.c | ${CC} ${aflags} -c -o ${2} -x c - && \
cp rtic_mp.c ${4} && \
${NM} --print-size --size-sort ${2} > ${3} && \
RTIC_MP_O=${2} || echo “RTIC MP generation has failed”
# NM - save generated variable sizes for verification
# RTIC_MP_O is our retval - great success if set to generated .o file
# Echo statement above prints the error message in case any of the
# above RTIC MP generation commands fail and it ensures rtic mp failure
# does not cause kernel compilation to fail.
}
# 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 .old_version
rm -f .tmp_System.map
rm -f .tmp_kallsyms*
rm -f .tmp_version
rm -f .tmp_symversions
rm -f .tmp_vmlinux*
rm -f built-in.o
rm -f System.map
rm -f vmlinux
rm -f vmlinux.o
rm -f .tmp_rtic_mp_sz*
rm -f rtic_mp.*
}
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
rm -f .version;
echo 1 >.version;
else
mv .version .old_version;
expr 0$(cat .old_version) + 1 >.version;
fi;
archive_builtin
#link vmlinux.o
modpost_link vmlinux.o
# modpost vmlinux.o to check for section mismatches
${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
# final build of init/
${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
if [ -n "${CONFIG_LTO_CLANG}" ]; then
# Re-use vmlinux.o, so we can avoid the slow LTO link step in
# vmlinux_link
KBUILD_VMLINUX_INIT=
KBUILD_VMLINUX_MAIN=vmlinux.o
# Call recordmcount if needed
recordmcount vmlinux.o
fi
# Generate RTIC MP placeholder compile unit of the correct size
# and add it to the list of link objects
# this needs to be done before generating kallsyms
if [ ! -z ${RTIC_MPGEN+x} ]; then
rtic_mp vmlinux.o rtic_mp.o .tmp_rtic_mp_sz1 .tmp_rtic_mp1.c
KBUILD_VMLINUX_MAIN+=" "
KBUILD_VMLINUX_MAIN+=$RTIC_MP_O
fi
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
# 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.
#
# a) Verify that the System.map from vmlinux matches the map from
# ${kallsymso}.
kallsymso=.tmp_kallsyms2.o
kallsyms_vmlinux=.tmp_vmlinux2
# step 1
vmlinux_link "" .tmp_vmlinux1
kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
# step 2
vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
# step 2a
if [ -n "${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
# Update RTIC MP object by replacing the place holder
# with actual MP data of the same size
# Also double check that object size did not change
# Note: Check initilally if RTIC_MP_O is not empty or uninitialized,
# as incase RTIC_MPGEN is set and failure occurs in RTIC_MP_O
# generation, below check for comparing object sizes fails
# due to an empty RTIC_MP_O object.
if [ ! -z ${RTIC_MP_O} ]; then
rtic_mp "${kallsyms_vmlinux}" rtic_mp.o .tmp_rtic_mp_sz2 \
.tmp_rtic_mp2.c
if ! cmp -s .tmp_rtic_mp_sz1 .tmp_rtic_mp_sz2; then
echo >&2 'ERROR: RTIC MP object files size mismatch'
exit 1
fi
fi
info LD vmlinux
vmlinux_link "${kallsymso}" vmlinux
if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
gen_btf vmlinux
fi
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
# We made a new kernel - delete old version file
rm -f .old_version