3204a7fb98
VPATH is used in Kbuild to make pattern rules search for prerequisites in both $(objtree) and $(srctree). Some of *.c, *.S files are not real sources, but generated by tools such as flex, bison, perl. In contrast, I doubt the benefit of --include-dir=$(abs_srctree) because it is always clear which Makefiles are real sources, and which are not. So, my hope is to add $(srctree)/ prefix to all check-in Makefiles, then remove --include-dir=$(abs_srctree) flag in the future. I am touching only some Kbuild core parts for now. Treewide fixes will be needed to achieve this goal. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
151 lines
4.5 KiB
Makefile
151 lines
4.5 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 $(srctree)/scripts/Kbuild.include
|
|
|
|
# for ld_flags
|
|
include $(srctree)/scripts/Makefile.lib
|
|
|
|
MODPOST = scripts/mod/modpost \
|
|
$(if $(CONFIG_MODVERSIONS),-m) \
|
|
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
|
|
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
|
|
$(if $(KBUILD_MODPOST_WARN),-w) \
|
|
-o $@
|
|
|
|
ifdef MODPOST_VMLINUX
|
|
|
|
quiet_cmd_modpost = MODPOST $@
|
|
cmd_modpost = $(MODPOST) $<
|
|
|
|
vmlinux.symvers: vmlinux.o
|
|
$(call cmd,modpost)
|
|
|
|
__modpost: vmlinux.symvers
|
|
|
|
else
|
|
|
|
ifeq ($(KBUILD_EXTMOD),)
|
|
|
|
input-symdump := vmlinux.symvers
|
|
output-symdump := Module.symvers
|
|
|
|
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)
|
|
|
|
# modpost option for external modules
|
|
MODPOST += -e
|
|
|
|
input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
|
|
output-symdump := $(KBUILD_EXTMOD)/Module.symvers
|
|
|
|
endif
|
|
|
|
# modpost options for modules (both in-kernel and external)
|
|
MODPOST += \
|
|
$(addprefix -i ,$(wildcard $(input-symdump))) \
|
|
$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
|
|
$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)
|
|
|
|
# 'make -i -k' ignores compile errors, and builds as many modules as possible.
|
|
ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
|
|
MODPOST += -n
|
|
endif
|
|
|
|
# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
|
|
VPATH :=
|
|
$(input-symdump):
|
|
@echo >&2 'WARNING: Symbol version dump "$@" is missing.'
|
|
@echo >&2 ' Modules may not have dependencies or modversions.'
|
|
|
|
ifdef CONFIG_LTO_CLANG
|
|
# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run
|
|
# LTO to compile them into native code before running modpost
|
|
prelink-ext := .lto
|
|
|
|
quiet_cmd_cc_lto_link_modules = LTO [M] $@
|
|
cmd_cc_lto_link_modules = \
|
|
$(LD) $(ld_flags) -r -o $@ \
|
|
$(shell [ -s $(@:.lto.o=.o.symversions) ] && \
|
|
echo -T $(@:.lto.o=.o.symversions)) \
|
|
--whole-archive $^
|
|
|
|
%.lto.o: %.o
|
|
$(call if_changed,cc_lto_link_modules)
|
|
endif
|
|
|
|
modules := $(sort $(shell cat $(MODORDER)))
|
|
|
|
# Read out modules.order to pass in modpost.
|
|
# Otherwise, allmodconfig would fail with "Argument list too long".
|
|
quiet_cmd_modpost = MODPOST $@
|
|
cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T -
|
|
|
|
$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE
|
|
$(call if_changed,modpost)
|
|
|
|
targets += $(output-symdump)
|
|
|
|
__modpost: $(output-symdump)
|
|
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
|
|
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
|
|
endif
|
|
|
|
PHONY += FORCE
|
|
FORCE:
|
|
|
|
existing-targets := $(wildcard $(sort $(targets)))
|
|
|
|
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
|
|
|
|
endif
|
|
|
|
.PHONY: $(PHONY)
|