kbuild: split final module linking out into Makefile.modfinal

I think splitting the modpost and linking modules into separate
Makefiles will be useful especially when more complex build steps
come in. The main motivation of this commit is to integrate the
proposed klp-convert feature cleanly.

I moved the logging 'Building modules, stage 2.' to Makefile.modpost
to avoid the code duplication although I do not know whether or not
this message is needed in the first place.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Masahiro Yamada 2019-08-15 01:06:23 +09:00
parent 10df063855
commit 9b9a3f20cb
3 changed files with 71 additions and 70 deletions

View file

@ -1304,7 +1304,6 @@ all: modules
PHONY += modules
modules: $(if $(KBUILD_BUILTIN),vmlinux) modules.order modules.builtin
@$(kecho) ' Building modules, stage 2.';
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
@ -1624,7 +1623,6 @@ $(objtree)/Module.symvers:
build-dirs := $(KBUILD_EXTMOD)
PHONY += modules
modules: descend $(objtree)/Module.symvers
@$(kecho) ' Building modules, stage 2.';
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
PHONY += modules_install

60
scripts/Makefile.modfinal Normal file
View file

@ -0,0 +1,60 @@
# SPDX-License-Identifier: GPL-2.0-only
# ===========================================================================
# Module final link
# ===========================================================================
PHONY := __modfinal
__modfinal:
include $(srctree)/scripts/Kbuild.include
# for c_flags
include $(srctree)/scripts/Makefile.lib
# find all modules listed in modules.order
modules := $(sort $(shell cat $(MODORDER)))
__modfinal: $(modules)
@:
# modname is set to make c_flags define KBUILD_MODNAME
modname = $(notdir $(@:.mod.o=))
quiet_cmd_cc_o_c = CC [M] $@
cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
-c -o $@ $<
%.mod.o: %.mod.c FORCE
$(call if_changed_dep,cc_o_c)
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
quiet_cmd_ld_ko_o = LD [M] $@
cmd_ld_ko_o = \
$(LD) -r $(KBUILD_LDFLAGS) \
$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
$(addprefix -T , $(KBUILD_LDS_MODULE)) \
-o $@ $(filter %.o, $^); \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
$(modules): %.ko: %.o %.mod.o $(KBUILD_LDS_MODULE) FORCE
+$(call if_changed,ld_ko_o)
targets += $(modules) $(modules:.ko=.mod.o)
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
PHONY += FORCE
FORCE:
# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.
existing-targets := $(wildcard $(sort $(targets)))
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
.PHONY: $(PHONY)

View file

@ -15,8 +15,6 @@
# 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
# 5) compile all <module>.mod.c files
# 6) final link of the module to a <module.ko> file
# Step 3 is used to place certain information in the module's ELF
# section, including information such as:
@ -60,13 +58,10 @@ MODPOST = scripts/mod/modpost \
ifdef MODPOST_VMLINUX
__modpost: vmlinux.o
quiet_cmd_modpost = MODPOST vmlinux.o
cmd_modpost = $(MODPOST) vmlinux.o
quiet_cmd_modpost = MODPOST $@
cmd_modpost = $(MODPOST) $@
PHONY += vmlinux.o
vmlinux.o:
__modpost:
$(call cmd,modpost)
else
@ -83,74 +78,22 @@ include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
$(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
endif
include scripts/Makefile.lib
MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux)
# find all modules listed in modules.order
modules := $(sort $(shell cat $(MODORDER)))
# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
__modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
@:
MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux)
# We can go over command line length here, so be careful.
# 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) | $(MODPOST)
PHONY += modules-modpost
modules-modpost:
__modpost:
@$(kecho) ' Building modules, stage 2.'
$(call cmd,modpost)
# Declare generated files as targets for modpost
$(modules:.ko=.mod.c): modules-modpost
# Step 5), compile all *.mod.c files
# modname is set to make c_flags define KBUILD_MODNAME
modname = $(notdir $(@:.mod.o=))
quiet_cmd_cc_o_c = CC [M] $@
cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
-c -o $@ $<
$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
$(call if_changed_dep,cc_o_c)
targets += $(modules:.ko=.mod.o)
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
# Step 6), final link of the modules with optional arch pass after final link
quiet_cmd_ld_ko_o = LD [M] $@
cmd_ld_ko_o = \
$(LD) -r $(KBUILD_LDFLAGS) \
$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
$(addprefix -T , $(KBUILD_LDS_MODULE)) \
-o $@ $(filter %.o, $^); \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
$(modules): %.ko :%.o %.mod.o $(KBUILD_LDS_MODULE) FORCE
+$(call if_changed,ld_ko_o)
targets += $(modules)
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
PHONY += FORCE
FORCE:
# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.
existing-targets := $(wildcard $(sort $(targets)))
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif
endif