mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
One of the most remarkable improvements in this cycle is, Kbuild is now able to cache the result of shell commands. Some variables are expensive to compute, for example, $(call cc-option,...) invokes the compiler. It is not efficient to redo this computation every time, even when we are not actually building anything. Kbuild creates a hidden file ".cache.mk" that contains invoked shell commands and their results. The speed-up should be noticeable. Summary: - Fix arch build issues (hexagon, sh) - Clean up various Makefiles and scripts - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles - Cache variables that are expensive to compute - Improve cc-ldopton and ld-option for Clang - Optimize output directory creation -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJaDxaLAAoJED2LAQed4NsGIHQP/isMxxaIxIAWU56+ZcII74k7 639VgrKi9n5y25d1dBRTQg+vReHE6E2JbkCqpVOu11t7m0LT7yUK8v3WwyLf1qTN GxnqZ/WMQU5/AYVqIWo8jN4FGHpivHJ6qbeiNJM9qN4RAkzG0sZUq746VaFZYmIR Lu0Gf4m4qjifkkhXsQdWT5i7yNTidPqaL6GNb+FcFkEHlVre8jma0kJlgfHxru84 WmETpjQXvHAZ/R61vY6ekAWpqFhw3ecJY96A9npnx+SQVQdSNAdpaU0SK29jB0ON /SAfpHg9oa/gD0LFOKV6zkjnAkd4TEjrJEiHHhz5gjT/SbS3T1llBIGZ1oV4X7Y0 Vlh9KWlm1FJJI4SIzc9qUaQMp6JtLfEfHKJCc45xVaN3fNrDnR8jl80x5+95ELga dCkZgnq5u82MtTysCbHBESwDYQaVPyIrh7In+mduglaCqhqj9KoDjoLoiGfCg7SA 3tPflYVd629w5l5GrazJ40jWn1+ggMtgMOVooJNJ+dINCP+GxsUpH84Ww2Pdic+/ qLdud6TeqxrZDGzWXqKNLu8alM8NGgSr101l9gIf1oqSyy63duBpMrxGDoIJS3FU rFDoFFUhlfkAXNbQHtVGNzKtcpCjURh992j9Fa1+NfMwSce5IHkMwTvPmNSRowi8 0llLjXhD/bxK6FpdvlV8 =zIdO -----END PGP SIGNATURE----- Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: "One of the most remarkable improvements in this cycle is, Kbuild is now able to cache the result of shell commands. Some variables are expensive to compute, for example, $(call cc-option,...) invokes the compiler. It is not efficient to redo this computation every time, even when we are not actually building anything. Kbuild creates a hidden file ".cache.mk" that contains invoked shell commands and their results. The speed-up should be noticeable. Summary: - Fix arch build issues (hexagon, sh) - Clean up various Makefiles and scripts - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles - Cache variables that are expensive to compute - Improve cc-ldopton and ld-option for Clang - Optimize output directory creation" * tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits) kbuild: move coccicheck help from scripts/Makefile.help to top Makefile sh: decompressor: add shipped files to .gitignore frv: .gitignore: ignore vmlinux.lds selinux: remove unnecessary assignment to subdir- kbuild: specify FORCE in Makefile.headersinst as .PHONY target kbuild: remove redundant mkdir from ./Kbuild kbuild: optimize object directory creation for incremental build kbuild: create object directories simpler and faster kbuild: filter-out PHONY targets from "targets" kbuild: remove redundant $(wildcard ...) for cmd_files calculation kbuild: create directory for make cache only when necessary sh: select KBUILD_DEFCONFIG depending on ARCH kbuild: fix linker feature test macros when cross compiling with Clang kbuild: shrink .cache.mk when it exceeds 1000 lines kbuild: do not call cc-option before KBUILD_CFLAGS initialization kbuild: Cache a few more calls to the compiler kbuild: Add a cache for generated variables kbuild: add forward declaration of default target to Makefile.asm-generic kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE ...
332 lines
7.6 KiB
Bash
Executable file
332 lines
7.6 KiB
Bash
Executable file
#!/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 $(KBUILD_VMLINUX_LIBS). Most are built-in.o files
|
|
# from top-level directories in the kernel tree, others are specified in
|
|
# arch/$(ARCH)/Makefile. Ordering when linking is important, and
|
|
# $(KBUILD_VMLINUX_INIT) must be first. $(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.o mm/built-in.o + 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} ${2}
|
|
fi
|
|
}
|
|
|
|
# Thin archive build here makes a final archive with symbol table and indexes
|
|
# from vmlinux objects INIT and MAIN, which can be used as input to linker.
|
|
# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes
|
|
# added.
|
|
#
|
|
# Traditional incremental style of link does not require this step
|
|
#
|
|
# built-in.o output file
|
|
#
|
|
archive_builtin()
|
|
{
|
|
if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
|
|
info AR built-in.o
|
|
rm -f built-in.o;
|
|
${AR} rcsTP${KBUILD_ARFLAGS} built-in.o \
|
|
${KBUILD_VMLINUX_INIT} \
|
|
${KBUILD_VMLINUX_MAIN}
|
|
fi
|
|
}
|
|
|
|
# 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 \
|
|
--no-whole-archive \
|
|
--start-group \
|
|
${KBUILD_VMLINUX_LIBS} \
|
|
--end-group"
|
|
else
|
|
objects="${KBUILD_VMLINUX_INIT} \
|
|
--start-group \
|
|
${KBUILD_VMLINUX_MAIN} \
|
|
${KBUILD_VMLINUX_LIBS} \
|
|
--end-group"
|
|
fi
|
|
${LD} ${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
|
|
if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
|
|
objects="--whole-archive \
|
|
built-in.o \
|
|
--no-whole-archive \
|
|
--start-group \
|
|
${KBUILD_VMLINUX_LIBS} \
|
|
--end-group \
|
|
${1}"
|
|
else
|
|
objects="${KBUILD_VMLINUX_INIT} \
|
|
--start-group \
|
|
${KBUILD_VMLINUX_MAIN} \
|
|
${KBUILD_VMLINUX_LIBS} \
|
|
--end-group \
|
|
${1}"
|
|
fi
|
|
|
|
${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \
|
|
-T ${lds} ${objects}
|
|
else
|
|
if [ -n "${CONFIG_THIN_ARCHIVES}" ]; then
|
|
objects="-Wl,--whole-archive \
|
|
built-in.o \
|
|
-Wl,--no-whole-archive \
|
|
-Wl,--start-group \
|
|
${KBUILD_VMLINUX_LIBS} \
|
|
-Wl,--end-group \
|
|
${1}"
|
|
else
|
|
objects="${KBUILD_VMLINUX_INIT} \
|
|
-Wl,--start-group \
|
|
${KBUILD_VMLINUX_MAIN} \
|
|
${KBUILD_VMLINUX_LIBS} \
|
|
-Wl,--end-group \
|
|
${1}"
|
|
fi
|
|
|
|
${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_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} | 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.o
|
|
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 GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
|
|
|
|
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
|
|
# ${kallsymso}.
|
|
|
|
kallsymso=.tmp_kallsyms2.o
|
|
kallsyms_vmlinux=.tmp_vmlinux2
|
|
|
|
# step 1
|
|
vmlinux_link "" .tmp_vmlinux1
|
|
kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
|
|
|
|
# step 2
|
|
vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
|
|
kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
|
|
|
|
# step 3
|
|
size1=$(stat -c "%s" .tmp_kallsyms1.o)
|
|
size2=$(stat -c "%s" .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
|