1# SPDX-License-Identifier: GPL-2.0 2# =========================================================================== 3# Module versions 4# =========================================================================== 5# 6# Stage one of module building created the following: 7# a) The individual .o files used for the module 8# b) A <module>.o file which is the .o files above linked together 9# c) A <module>.mod file, listing the name of the preliminary <module>.o file, 10# plus all .o files 11# d) modules.order, which lists all the modules 12 13# Stage 2 is handled by this file and does the following 14# 1) Find all modules listed in modules.order 15# 2) modpost is then used to 16# 3) create one <module>.mod.c file pr. module 17# 4) create one Module.symvers file with CRC for all exported symbols 18 19# Step 3 is used to place certain information in the module's ELF 20# section, including information such as: 21# Version magic (see include/linux/vermagic.h for full details) 22# - Kernel release 23# - SMP is CONFIG_SMP 24# - PREEMPT is CONFIG_PREEMPT[_RT] 25# - GCC Version 26# Module info 27# - Module version (MODULE_VERSION) 28# - Module alias'es (MODULE_ALIAS) 29# - Module license (MODULE_LICENSE) 30# - See include/linux/module.h for more details 31 32# Step 4 is solely used to allow module versioning in external modules, 33# where the CRC of each module is retrieved from the Module.symvers file. 34 35# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined 36# symbols in the final module linking stage 37# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. 38# This is solely useful to speed up test compiles 39 40PHONY := __modpost 41__modpost: 42 43include include/config/auto.conf 44include scripts/Kbuild.include 45 46MODPOST = scripts/mod/modpost \ 47 $(if $(CONFIG_MODVERSIONS),-m) \ 48 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 49 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 50 $(if $(KBUILD_MODPOST_WARN),-w) \ 51 -o $@ 52 53ifdef MODPOST_VMLINUX 54 55quiet_cmd_modpost = MODPOST $@ 56 cmd_modpost = $(MODPOST) $< 57 58vmlinux.symvers: vmlinux.o 59 $(call cmd,modpost) 60 61__modpost: vmlinux.symvers 62 63else 64 65MODPOST += \ 66 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) 67 68ifeq ($(KBUILD_EXTMOD),) 69 70input-symdump := vmlinux.symvers 71output-symdump := Module.symvers 72 73else 74 75# set src + obj - they may be used in the modules's Makefile 76obj := $(KBUILD_EXTMOD) 77src := $(obj) 78 79# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 80include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ 81 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) 82 83# modpost option for external modules 84MODPOST += -e 85 86input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) 87output-symdump := $(KBUILD_EXTMOD)/Module.symvers 88 89endif 90 91# modpost options for modules (both in-kernel and external) 92MODPOST += \ 93 $(addprefix -i ,$(wildcard $(input-symdump))) \ 94 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) 95 96# 'make -i -k' ignores compile errors, and builds as many modules as possible. 97ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 98MODPOST += -n 99endif 100 101# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). 102VPATH := 103$(input-symdump): 104 @echo >&2 'WARNING: Symbol version dump "$@" is missing.' 105 @echo >&2 ' Modules may not have dependencies or modversions.' 106 107# Read out modules.order to pass in modpost. 108# Otherwise, allmodconfig would fail with "Argument list too long". 109quiet_cmd_modpost = MODPOST $@ 110 cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T - 111 112$(output-symdump): $(MODORDER) $(input-symdump) FORCE 113 $(call if_changed,modpost) 114 115targets += $(output-symdump) 116 117__modpost: $(output-symdump) 118ifneq ($(KBUILD_MODPOST_NOFINAL),1) 119 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal 120endif 121 122PHONY += FORCE 123FORCE: 124 125existing-targets := $(wildcard $(sort $(targets))) 126 127-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 128 129PHONY += FORCE 130FORCE: 131 132endif 133 134.PHONY: $(PHONY) 135