name : Makefile.modpost # 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 per 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. PHONY := __modpost __modpost: include include/config/auto.conf include $(srctree)/scripts/Kbuild.include MODPOST = scripts/mod/modpost modpost-args = \ $(if $(CONFIG_MODULES),-M) \ $(if $(CONFIG_MODVERSIONS),-m) \ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ $(if $(KBUILD_MODPOST_WARN),-w) \ $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \ $(if $(findstring 1, $(KBUILD_EXTRA_WARN)),-W) \ -o $@ modpost-deps := $(MODPOST) # 'make -i -k' ignores compile errors, and builds as many modules as possible. ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) modpost-args += -n endif # Read out modules.order to pass in modpost. # Otherwise, allmodconfig would fail with "Argument list too long". ifdef KBUILD_MODULES modpost-args += -T $(MODORDER) modpost-deps += $(MODORDER) endif ifeq ($(KBUILD_EXTMOD),) # Generate the list of in-tree objects in vmlinux # --------------------------------------------------------------------------- # This is used to retrieve symbol versions generated by genksyms. ifdef CONFIG_MODVERSIONS vmlinux.symvers Module.symvers: .vmlinux.objs endif # Ignore libgcc.a # Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a # from the toolchain, but there is no EXPORT_SYMBOL in it. quiet_cmd_vmlinux_objs = GEN $@ cmd_vmlinux_objs = \ for f in $(real-prereqs); do \ case $${f} in \ *libgcc.a) ;; \ *) $(AR) t $${f} ;; \ esac \ done > $@ targets += .vmlinux.objs .vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE $(call if_changed,vmlinux_objs) ifdef CONFIG_TRIM_UNUSED_KSYMS ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST) ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$(srctree)/)$(ksym-wl) modpost-args += -t $(addprefix -u , $(ksym-wl)) modpost-deps += $(ksym-wl) endif ifeq ($(wildcard vmlinux.o),) missing-input := vmlinux.o output-symdump := modules-only.symvers else modpost-args += vmlinux.o modpost-deps += vmlinux.o output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers) endif 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 $(kbuild-file) output-symdump := $(KBUILD_EXTMOD)/Module.symvers ifeq ($(wildcard Module.symvers),) missing-input := Module.symvers else modpost-args += -i Module.symvers modpost-deps += Module.symvers endif modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS)) endif # ($(KBUILD_EXTMOD),) quiet_cmd_modpost = MODPOST $@ cmd_modpost = \ $(if $(missing-input), \ echo >&2 "WARNING: $(missing-input) is missing."; \ echo >&2 " Modules may not have dependencies or modversions."; \ echo >&2 " You may get many unresolved symbol errors."; \ echo >&2 " You can set KBUILD_MODPOST_WARN=1 to turn errors into warning"; \ echo >&2 " if you want to proceed at your own risk.";) \ $(MODPOST) $(modpost-args) targets += $(output-symdump) $(output-symdump): $(modpost-deps) FORCE $(call if_changed,modpost) __modpost: $(output-symdump) PHONY += FORCE FORCE: existing-targets := $(wildcard $(sort $(targets))) -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) .PHONY: $(PHONY)