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 44# for mod-prelink-ext 45include $(srctree)/scripts/Makefile.lib 46 47MODPOST = scripts/mod/modpost \ 48 $(if $(CONFIG_MODVERSIONS),-m) \ 49 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 50 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 51 -o $@ 52 53ifdef MODPOST_VMLINUX 54 55quiet_cmd_modpost = MODPOST $@ 56 cmd_modpost = $(MODPOST) $< 57 58vmlinux.symvers: vmlinux.o 59 $(call cmd,modpost) 60 61__modpost: vmlinux.symvers 62 63else 64 65ifeq ($(KBUILD_EXTMOD),) 66 67input-symdump := vmlinux.symvers 68output-symdump := modules-only.symvers 69 70quiet_cmd_cat = GEN $@ 71 cmd_cat = cat $(real-prereqs) > $@ 72 73ifneq ($(wildcard vmlinux.symvers),) 74 75__modpost: Module.symvers 76Module.symvers: vmlinux.symvers modules-only.symvers FORCE 77 $(call if_changed,cat) 78 79targets += Module.symvers 80 81endif 82 83else 84 85# set src + obj - they may be used in the modules's Makefile 86obj := $(KBUILD_EXTMOD) 87src := $(obj) 88 89# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 90include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ 91 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) 92 93# modpost option for external modules 94MODPOST += -e 95 96input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) 97output-symdump := $(KBUILD_EXTMOD)/Module.symvers 98 99endif 100 101existing-input-symdump := $(wildcard $(input-symdump)) 102 103# modpost options for modules (both in-kernel and external) 104MODPOST += \ 105 $(addprefix -i ,$(existing-input-symdump)) \ 106 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ 107 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) 108 109# 'make -i -k' ignores compile errors, and builds as many modules as possible. 110ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 111MODPOST += -n 112endif 113 114# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). 115VPATH := 116$(input-symdump): 117 @echo >&2 'WARNING: Symbol version dump "$@" is missing.' 118 @echo >&2 ' Modules may not have dependencies or modversions.' 119 @echo >&2 ' You may get many unresolved symbol warnings.' 120 121modules := $(sort $(shell cat $(MODORDER))) 122 123# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols 124ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),) 125MODPOST += -w 126endif 127 128# Read out modules.order to pass in modpost. 129# Otherwise, allmodconfig would fail with "Argument list too long". 130quiet_cmd_modpost = MODPOST $@ 131 cmd_modpost = sed 's/\.ko$$/$(mod-prelink-ext)\.o/' $< | $(MODPOST) -T - 132 133$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(mod-prelink-ext).o) FORCE 134 $(call if_changed,modpost) 135 136targets += $(output-symdump) 137 138__modpost: $(output-symdump) 139ifneq ($(KBUILD_MODPOST_NOFINAL),1) 140 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal 141endif 142 143PHONY += FORCE 144FORCE: 145 146existing-targets := $(wildcard $(sort $(targets))) 147 148-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 149 150endif 151 152.PHONY: $(PHONY) 153