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 47mixed-build-prefix = $(if $(KBUILD_MIXED_TREE),$(KBUILD_MIXED_TREE)/) 48 49MODPOST = scripts/mod/modpost \ 50 $(if $(CONFIG_MODVERSIONS),-m) \ 51 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 52 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 53 -o $@ 54 55ifdef MODPOST_VMLINUX 56 57quiet_cmd_modpost = MODPOST $@ 58 cmd_modpost = $(MODPOST) $< 59 60vmlinux.symvers: vmlinux.o 61 $(call cmd,modpost) 62 63__modpost: vmlinux.symvers 64 65else 66 67ifeq ($(KBUILD_EXTMOD),) 68 69input-symdump := $(mixed-build-prefix)vmlinux.symvers 70output-symdump := modules-only.symvers 71module_srcpath := $(srctree) 72 73quiet_cmd_cat = GEN $@ 74 cmd_cat = cat $(real-prereqs) > $@ 75 76ifneq ($(wildcard $(mixed-build-prefix)vmlinux.symvers),) 77 78__modpost: Module.symvers 79Module.symvers: $(mixed-build-prefix)vmlinux.symvers modules-only.symvers FORCE 80 $(call if_changed,cat) 81 82targets += Module.symvers 83 84endif 85 86else 87 88# set src + obj - they may be used in the modules's Makefile 89obj := $(KBUILD_EXTMOD) 90src := $(obj) 91 92# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 93include $(if $(wildcard $(src)/Kbuild), $(src)/Kbuild, $(src)/Makefile) 94 95# modpost option for external modules 96MODPOST += -e 97 98input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) 99output-symdump := $(KBUILD_EXTMOD)/Module.symvers 100 101# Get the external module's source path. KBUILD_EXTMOD could either be an 102# absolute path or relative path from $(srctree). This makes sure that we 103# aren't using a relative path from a separate working directory (O= or 104# KBUILD_OUTPUT) since that may not be the actual module's SCM project path. So 105# check the path relative to $(srctree) first. 106ifneq ($(realpath $(srctree)/$(KBUILD_EXTMOD) 2>/dev/null),) 107 module_srcpath := $(srctree)/$(KBUILD_EXTMOD) 108else 109 module_srcpath := $(KBUILD_EXTMOD) 110endif 111 112endif 113 114ifeq ($(CONFIG_MODULE_SCMVERSION),y) 115# Get the SCM version of the module. `sed` verifies setlocalversion returns 116# a proper revision based on the SCM type, e.g. git, mercurial, or svn. 117module_scmversion := $(shell $(srctree)/scripts/setlocalversion $(module_srcpath) | \ 118 sed -n 's/.*-\(\(g\|hg\)[a-fA-F0-9]\+\(-dirty\)\?\|svn[0-9]\+\).*/\1/p') 119ifneq ($(module_scmversion),) 120MODPOST += -v $(module_scmversion) 121endif 122endif 123 124existing-input-symdump := $(wildcard $(input-symdump)) 125 126# modpost options for modules (both in-kernel and external) 127MODPOST += \ 128 $(addprefix -i ,$(existing-input-symdump)) \ 129 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ 130 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) 131 132# 'make -i -k' ignores compile errors, and builds as many modules as possible. 133ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 134MODPOST += -n 135endif 136 137# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). 138VPATH := 139$(input-symdump): 140 @echo >&2 'WARNING: Symbol version dump "$@" is missing.' 141 @echo >&2 ' Modules may not have dependencies or modversions.' 142 @echo >&2 ' You may get many unresolved symbol warnings.' 143 144modules := $(sort $(shell cat $(MODORDER))) 145 146# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols 147ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),) 148MODPOST += -w 149endif 150 151# Read out modules.order to pass in modpost. 152# Otherwise, allmodconfig would fail with "Argument list too long". 153quiet_cmd_modpost = MODPOST $@ 154 cmd_modpost = sed 's/\.ko$$/$(mod-prelink-ext)\.o/' $< | $(MODPOST) -T - 155 156$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(mod-prelink-ext).o) FORCE 157 $(call if_changed,modpost) 158 159targets += $(output-symdump) 160 161__modpost: $(output-symdump) 162ifneq ($(KBUILD_MODPOST_NOFINAL),1) 163 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal 164endif 165 166PHONY += FORCE 167FORCE: 168 169existing-targets := $(wildcard $(sort $(targets))) 170 171-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 172 173endif 174 175.PHONY: $(PHONY) 176