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 35PHONY := __modpost 36__modpost: 37 38include include/config/auto.conf 39include $(srctree)/scripts/Kbuild.include 40 41MODPOST = scripts/mod/modpost 42 43modpost-args = \ 44 $(if $(CONFIG_MODVERSIONS),-m) \ 45 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 46 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 47 $(if $(KBUILD_MODPOST_WARN),-w) \ 48 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ 49 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \ 50 $(if $(findstring 1, $(KBUILD_EXTRA_WARN)),-W) \ 51 -o $@ 52 53modpost-deps := $(MODPOST) 54 55# 'make -i -k' ignores compile errors, and builds as many modules as possible. 56ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 57modpost-args += -n 58endif 59 60# Read out modules.order to pass in modpost. 61# Otherwise, allmodconfig would fail with "Argument list too long". 62ifdef KBUILD_MODULES 63modpost-args += -T $(MODORDER) 64modpost-deps += $(MODORDER) 65endif 66 67ifeq ($(KBUILD_EXTMOD),) 68 69# Generate the list of in-tree objects in vmlinux 70# --------------------------------------------------------------------------- 71 72# This is used to retrieve symbol versions generated by genksyms. 73ifdef CONFIG_MODVERSIONS 74vmlinux.symvers Module.symvers: .vmlinux.objs 75endif 76 77# Ignore libgcc.a 78# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a 79# from the toolchain, but there is no EXPORT_SYMBOL in it. 80 81quiet_cmd_vmlinux_objs = GEN $@ 82 cmd_vmlinux_objs = \ 83 for f in $(real-prereqs); do \ 84 case $${f} in \ 85 *libgcc.a) ;; \ 86 *) $(AR) t $${f} ;; \ 87 esac \ 88 done > $@ 89 90targets += .vmlinux.objs 91.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE 92 $(call if_changed,vmlinux_objs) 93 94ifdef CONFIG_TRIM_UNUSED_KSYMS 95ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST) 96ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$(srctree)/)$(ksym-wl) 97modpost-args += -t $(addprefix -u , $(ksym-wl)) 98modpost-deps += $(ksym-wl) 99endif 100 101ifeq ($(wildcard vmlinux.o),) 102missing-input := vmlinux.o 103output-symdump := modules-only.symvers 104else 105modpost-args += vmlinux.o 106modpost-deps += vmlinux.o 107output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers) 108endif 109 110else 111 112# set src + obj - they may be used in the modules's Makefile 113obj := $(KBUILD_EXTMOD) 114src := $(obj) 115 116# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 117include $(kbuild-file) 118 119output-symdump := $(KBUILD_EXTMOD)/Module.symvers 120 121ifeq ($(wildcard Module.symvers),) 122missing-input := Module.symvers 123else 124modpost-args += -i Module.symvers 125modpost-deps += Module.symvers 126endif 127 128modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS)) 129 130endif # ($(KBUILD_EXTMOD),) 131 132quiet_cmd_modpost = MODPOST $@ 133 cmd_modpost = \ 134 $(if $(missing-input), \ 135 echo >&2 "WARNING: $(missing-input) is missing."; \ 136 echo >&2 " Modules may not have dependencies or modversions."; \ 137 echo >&2 " You may get many unresolved symbol errors."; \ 138 echo >&2 " You can set KBUILD_MODPOST_WARN=1 to turn errors into warning"; \ 139 echo >&2 " if you want to proceed at your own risk.";) \ 140 $(MODPOST) $(modpost-args) 141 142targets += $(output-symdump) 143$(output-symdump): $(modpost-deps) FORCE 144 $(call if_changed,modpost) 145 146__modpost: $(output-symdump) 147PHONY += FORCE 148FORCE: 149 150existing-targets := $(wildcard $(sort $(targets))) 151 152-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 153 154.PHONY: $(PHONY) 155