kernel_optimize_test/scripts/Makefile.modpost
Masahiro Yamada 1747269ab0 modpost: do not parse vmlinux for external module builds
When building external modules, $(objtree)/Module.symvers is scanned
for symbol information of vmlinux and in-tree modules.

Additionally, vmlinux is parsed if it exists in $(objtree)/.
This is totally redundant since all the necessary information is
contained in $(objtree)/Module.symvers.

Do not parse vmlinux at all for external module builds. This makes
sense because vmlinux is deleted by 'make clean'.

'make clean' leaves all the build artifacts for building external
modules. vmlinux is unneeded for that.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-11-11 20:07:03 +09:00

105 lines
3.3 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# ===========================================================================
# Module versions
# ===========================================================================
#
# Stage one of module building created the following:
# a) The individual .o files used for the module
# b) A <module>.o file which is the .o files above linked together
# c) A <module>.mod file, listing the name of the preliminary <module>.o file,
# plus all .o files
# d) modules.order, which lists all the modules
# Stage 2 is handled by this file and does the following
# 1) Find all modules listed in modules.order
# 2) modpost is then used to
# 3) create one <module>.mod.c file pr. module
# 4) create one Module.symvers file with CRC for all exported symbols
# Step 3 is used to place certain information in the module's ELF
# section, including information such as:
# Version magic (see include/linux/vermagic.h for full details)
# - Kernel release
# - SMP is CONFIG_SMP
# - PREEMPT is CONFIG_PREEMPT[_RT]
# - GCC Version
# Module info
# - Module version (MODULE_VERSION)
# - Module alias'es (MODULE_ALIAS)
# - Module license (MODULE_LICENSE)
# - See include/linux/module.h for more details
# Step 4 is solely used to allow module versioning in external modules,
# where the CRC of each module is retrieved from the Module.symvers file.
# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
# symbols in the final module linking stage
# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
# This is solely useful to speed up test compiles
PHONY := __modpost
__modpost:
include include/config/auto.conf
include scripts/Kbuild.include
kernelsymfile := $(objtree)/Module.symvers
modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
MODPOST = scripts/mod/modpost \
$(if $(CONFIG_MODVERSIONS),-m) \
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \
$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
$(if $(KBUILD_MODPOST_WARN),-w) \
$(if $(filter nsdeps,$(MAKECMDGOALS)),-d)
ifdef MODPOST_VMLINUX
quiet_cmd_modpost = MODPOST vmlinux.o
cmd_modpost = $(MODPOST) vmlinux.o
__modpost:
$(call cmd,modpost)
else
MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T -
ifeq ($(KBUILD_EXTMOD),)
MODPOST += $(wildcard vmlinux)
else
# set src + obj - they may be used in the modules's Makefile
obj := $(KBUILD_EXTMOD)
src := $(obj)
# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
$(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
endif
# find all modules listed in modules.order
modules := $(sort $(shell cat $(MODORDER)))
# Read out modules.order instead of expanding $(modules) to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
quiet_cmd_modpost = MODPOST $(words $(modules)) modules
cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
__modpost:
@$(kecho) ' Building modules, stage 2.'
$(call cmd,modpost)
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif
nsdeps: __modpost
endif
.PHONY: $(PHONY)