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 46# for ld_flags 47include scripts/Makefile.lib 48 49mixed-build-prefix = $(if $(KBUILD_MIXED_TREE),$(KBUILD_MIXED_TREE)/) 50 51MODPOST = scripts/mod/modpost \ 52 $(if $(CONFIG_MODVERSIONS),-m) \ 53 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 54 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 55 $(if $(KBUILD_MODPOST_WARN),-w) \ 56 -o $@ 57 58ifdef MODPOST_VMLINUX 59 60quiet_cmd_modpost = MODPOST $@ 61 cmd_modpost = $(MODPOST) $< 62 63vmlinux.symvers: vmlinux.o 64 $(call cmd,modpost) 65 66__modpost: vmlinux.symvers 67 68else 69 70ifeq ($(KBUILD_EXTMOD),) 71 72input-symdump := $(mixed-build-prefix)vmlinux.symvers 73output-symdump := modules-only.symvers 74module_srcpath := $(srctree) 75 76quiet_cmd_cat = GEN $@ 77 cmd_cat = cat $(real-prereqs) > $@ 78 79ifneq ($(wildcard $(mixed-build-prefix)vmlinux.symvers),) 80 81__modpost: Module.symvers 82Module.symvers: $(mixed-build-prefix)vmlinux.symvers modules-only.symvers FORCE 83 $(call if_changed,cat) 84 85targets += Module.symvers 86 87endif 88 89else 90 91# set src + obj - they may be used in the modules's Makefile 92obj := $(KBUILD_EXTMOD) 93src := $(obj) 94 95# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 96include $(if $(wildcard $(src)/Kbuild), $(src)/Kbuild, $(src)/Makefile) 97 98# modpost option for external modules 99MODPOST += -e 100 101input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) 102output-symdump := $(KBUILD_EXTMOD)/Module.symvers 103 104# Get the external module's source path. KBUILD_EXTMOD could either be an 105# absolute path or relative path from $(srctree). This makes sure that we 106# aren't using a relative path from a separate working directory (O= or 107# KBUILD_OUTPUT) since that may not be the actual module's SCM project path. So 108# check the path relative to $(srctree) first. 109ifneq ($(realpath $(srctree)/$(KBUILD_EXTMOD) 2>/dev/null),) 110 module_srcpath := $(srctree)/$(KBUILD_EXTMOD) 111else 112 module_srcpath := $(KBUILD_EXTMOD) 113endif 114 115endif 116 117ifeq ($(CONFIG_MODULE_SCMVERSION),y) 118# Get the SCM version of the module. `sed` verifies setlocalversion returns 119# a proper revision based on the SCM type, e.g. git, mercurial, or svn. 120module_scmversion := $(shell $(srctree)/scripts/setlocalversion $(module_srcpath) | \ 121 sed -n 's/.*-\(\(g\|hg\)[a-fA-F0-9]\+\(-dirty\)\?\|svn[0-9]\+\).*/\1/p') 122ifneq ($(module_scmversion),) 123MODPOST += -v $(module_scmversion) 124endif 125endif 126 127# modpost options for modules (both in-kernel and external) 128MODPOST += \ 129 $(addprefix -i ,$(wildcard $(input-symdump))) \ 130 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ 131 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) 132 133# 'make -i -k' ignores compile errors, and builds as many modules as possible. 134ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 135MODPOST += -n 136endif 137 138# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). 139VPATH := 140$(input-symdump): 141 @echo >&2 'WARNING: Symbol version dump "$@" is missing.' 142 @echo >&2 ' Modules may not have dependencies or modversions.' 143 144ifdef CONFIG_LTO_CLANG 145# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run 146# LTO to compile them into native code before running modpost 147prelink-ext := .lto 148 149quiet_cmd_cc_lto_link_modules = LTO [M] $@ 150cmd_cc_lto_link_modules = \ 151 $(LD) $(ld_flags) -r -o $@ \ 152 $(shell [ -s $(@:.lto.o=.o.symversions) ] && \ 153 echo -T $(@:.lto.o=.o.symversions)) \ 154 --whole-archive $^ 155 156%.lto.o: %.o 157 $(call if_changed,cc_lto_link_modules) 158endif 159 160modules := $(sort $(shell cat $(MODORDER))) 161 162# Read out modules.order to pass in modpost. 163# Otherwise, allmodconfig would fail with "Argument list too long". 164quiet_cmd_modpost = MODPOST $@ 165 cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T - 166 167$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE 168 $(call if_changed,modpost) 169 170targets += $(output-symdump) 171 172__modpost: $(output-symdump) 173ifneq ($(KBUILD_MODPOST_NOFINAL),1) 174 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal 175endif 176 177PHONY += FORCE 178FORCE: 179 180existing-targets := $(wildcard $(sort $(targets))) 181 182-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 183 184endif 185 186.PHONY: $(PHONY) 187