# 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 .o file which is the .o files above linked together # c) A .mod file, listing the name of the preliminary .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 .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 $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \ $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ $(if $(KBUILD_MODPOST_WARN),-w) 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 - \ $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) ifeq ($(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: $(call cmd,modpost) ifneq ($(KBUILD_MODPOST_NOFINAL),1) $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal endif endif .PHONY: $(PHONY)