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#!/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} \
${KBUILD_VMLINUX_MAIN}
# rebuild with llvm-ar to update the symbol table
if [ -n "${CONFIG_LTO_CLANG}" ]; then
mv -f built-in.a built-in.a.tmp
${LLVM_AR} rcsT${KBUILD_ARFLAGS} built-in.a $(${AR} t built-in.a.tmp)
rm -f built-in.a.tmp
fi
}
# If CONFIG_LTO_CLANG is selected, generate a linker script to ensure correct
# ordering of initcalls, and with CONFIG_MODVERSIONS also enabled, collect the
# previously generated symbol versions into the same script.
lto_lds()
{
if [ -z "${CONFIG_LTO_CLANG}" ]; then
return
fi
${srctree}/scripts/generate_initcall_order.pl \
built-in.a ${KBUILD_VMLINUX_LIBS} \
> .tmp_lto.lds
if [ -n "${CONFIG_MODVERSIONS}" ]; then
for a in built-in.a ${KBUILD_VMLINUX_LIBS}; do
for o in $(${AR} t $a); do
if [ -f ${o}.symversions ]; then
cat ${o}.symversions >> .tmp_lto.lds
fi
done
done
fi
echo "-T .tmp_lto.lds"
}
# 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 \
${KBUILD_VMLINUX_LIBS} \
--end-group"
if [ -n "${CONFIG_LTO_CLANG}" ]; then
# This might take a while, so indicate that we're doing
# an LTO link
info LTO vmlinux.o
fi
${LD} ${KBUILD_LDFLAGS} -r -o ${1} $(lto_lds) ${objects}
}
# If CONFIG_LTO_CLANG is selected, we postpone running recordmcount until
# we have compiled LLVM IR to an object file.
recordmcount()
{
if [ -z "${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
if [ -z "${CONFIG_LTO_CLANG}" ]; then
objects="--whole-archive \
built-in.a \
--no-whole-archive \
--start-group \
${KBUILD_VMLINUX_LIBS} \
--end-group \
${1}"
else
objects="--start-group \
vmlinux.o \
--end-group \
${1}"
fi
${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}
}
# 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 .tmp_System.map
rm -f .tmp_kallsyms*
rm -f .tmp_lto.lds
rm -f .tmp_vmlinux*
rm -f built-in.a
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 [ "$1" = "clean" ]; then
cleanup
exit 0
fi
# We need access to CONFIG_ symbols
. include/config/auto.conf
# Update version
info GEN .version
if [ -r .version ]; then
VERSION=$(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
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
if [ -n "${CONFIG_LTO_CLANG}" ]; then
# 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 ${RTIC_MPGEN+x} ]; then
rtic_mp vmlinux.o rtic_mp.o .tmp_rtic_mp_sz1 .tmp_rtic_mp1.c
KBUILD_VMLINUX_LIBS+=" "
KBUILD_VMLINUX_LIBS+=$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
# 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
# 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_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
# Starting Android Q, the DTB's are part of dtb.img and not part
# of the kernel image. RTIC DTS relies on the kernel environment
# and could not build outside of the kernel. Generate RTIC DTS after
# successful kernel build if MPGen is enabled. The DTB will be
# generated with dtb.img in kernel_definitions.mk.
if [ ! -z ${RTIC_MPGEN+x} ]; then
${RTIC_MPGEN} --objcopy="${OBJCOPY}" --objdump="${OBJDUMP}" \
--binpath="" --vmlinux="vmlinux" --config=${KCONFIG_CONFIG} \
--cc="${CC} ${KBUILD_AFLAGS}" --dts=rtic_mp.dts \
|| echo RTIC MP DTS generation has failed
# Echo statement above prints the error message in case above
# RTIC MP DTS generation command fails and it ensures rtic mp
# failure does not cause kernel compilation to fail.
fi