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 per 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_NOFINAL can be set to skip the final link of modules. 36# This is solely useful to speed up test compiles 37 38PHONY := __modpost 39__modpost: 40 41include include/config/auto.conf 42include $(srctree)/scripts/Kbuild.include 43 44MODPOST = scripts/mod/modpost \ 45 $(if $(CONFIG_MODVERSIONS),-m) \ 46 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 47 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 48 -o $@ 49 50ifdef MODPOST_VMLINUX 51 52quiet_cmd_modpost = MODPOST $@ 53 cmd_modpost = $(MODPOST) $< 54 55vmlinux.symvers: vmlinux.o 56 $(call cmd,modpost) 57 58__modpost: vmlinux.symvers 59 60else 61 62ifeq ($(KBUILD_EXTMOD),) 63 64input-symdump := vmlinux.symvers 65output-symdump := modules-only.symvers 66 67quiet_cmd_cat = GEN $@ 68 cmd_cat = cat $(real-prereqs) > $@ 69 70ifneq ($(wildcard vmlinux.symvers),) 71 72__modpost: Module.symvers 73Module.symvers: vmlinux.symvers modules-only.symvers FORCE 74 $(call if_changed,cat) 75 76targets += Module.symvers 77 78endif 79 80else 81 82# set src + obj - they may be used in the modules's Makefile 83obj := $(KBUILD_EXTMOD) 84src := $(obj) 85 86# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 87include $(or $(wildcard $(src)/Kbuild), $(src)/Makefile) 88 89# modpost option for external modules 90MODPOST += -e 91 92input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) 93output-symdump := $(KBUILD_EXTMOD)/Module.symvers 94 95endif 96 97existing-input-symdump := $(wildcard $(input-symdump)) 98 99# modpost options for modules (both in-kernel and external) 100MODPOST += \ 101 $(addprefix -i ,$(existing-input-symdump)) \ 102 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ 103 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) 104 105# 'make -i -k' ignores compile errors, and builds as many modules as possible. 106ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 107MODPOST += -n 108endif 109 110# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). 111VPATH := 112$(input-symdump): 113 @echo >&2 'WARNING: Symbol version dump "$@" is missing.' 114 @echo >&2 ' Modules may not have dependencies or modversions.' 115 @echo >&2 ' You may get many unresolved symbol warnings.' 116 117# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols 118ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),) 119MODPOST += -w 120endif 121 122# Read out modules.order to pass in modpost. 123# Otherwise, allmodconfig would fail with "Argument list too long". 124quiet_cmd_modpost = MODPOST $@ 125 cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T - 126 127$(output-symdump): $(MODORDER) $(input-symdump) FORCE 128 $(call if_changed,modpost) 129 130targets += $(output-symdump) 131 132__modpost: $(output-symdump) 133ifneq ($(KBUILD_MODPOST_NOFINAL),1) 134 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal 135endif 136 137PHONY += FORCE 138FORCE: 139 140existing-targets := $(wildcard $(sort $(targets))) 141 142-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 143 144endif 145 146.PHONY: $(PHONY) 147