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_MODULES),-M) \ 45 $(if $(CONFIG_MODVERSIONS),-m) \ 46 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ 47 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ 48 $(if $(KBUILD_MODPOST_WARN),-w) \ 49 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ 50 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \ 51 $(if $(findstring 1, $(KBUILD_EXTRA_WARN)),-W) \ 52 -o $@ 53 54modpost-deps := $(MODPOST) 55 56# 'make -i -k' ignores compile errors, and builds as many modules as possible. 57ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) 58modpost-args += -n 59endif 60 61# Read out modules.order to pass in modpost. 62# Otherwise, allmodconfig would fail with "Argument list too long". 63ifdef KBUILD_MODULES 64modpost-args += -T $(MODORDER) 65modpost-deps += $(MODORDER) 66endif 67 68ifeq ($(KBUILD_EXTMOD),) 69 70# Generate the list of in-tree objects in vmlinux 71# --------------------------------------------------------------------------- 72 73# This is used to retrieve symbol versions generated by genksyms. 74ifdef CONFIG_MODVERSIONS 75vmlinux.symvers Module.symvers: .vmlinux.objs 76endif 77 78# Ignore libgcc.a 79# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a 80# from the toolchain, but there is no EXPORT_SYMBOL in it. 81 82quiet_cmd_vmlinux_objs = GEN $@ 83 cmd_vmlinux_objs = \ 84 for f in $(real-prereqs); do \ 85 case $${f} in \ 86 *libgcc.a) ;; \ 87 *) $(AR) t $${f} ;; \ 88 esac \ 89 done > $@ 90 91targets += .vmlinux.objs 92.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE 93 $(call if_changed,vmlinux_objs) 94 95ifdef CONFIG_TRIM_UNUSED_KSYMS 96ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST) 97ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$(srctree)/)$(ksym-wl) 98modpost-args += -t $(addprefix -u , $(ksym-wl)) 99modpost-deps += $(ksym-wl) 100endif 101 102ifeq ($(wildcard vmlinux.o),) 103missing-input := vmlinux.o 104output-symdump := modules-only.symvers 105else 106modpost-args += vmlinux.o 107modpost-deps += vmlinux.o 108output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers) 109endif 110 111else 112 113# set src + obj - they may be used in the modules's Makefile 114obj := $(KBUILD_EXTMOD) 115src := $(obj) 116 117# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS 118include $(kbuild-file) 119 120output-symdump := $(KBUILD_EXTMOD)/Module.symvers 121 122ifeq ($(wildcard Module.symvers),) 123missing-input := Module.symvers 124else 125modpost-args += -i Module.symvers 126modpost-deps += Module.symvers 127endif 128 129modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS)) 130 131endif # ($(KBUILD_EXTMOD),) 132 133quiet_cmd_modpost = MODPOST $@ 134 cmd_modpost = \ 135 $(if $(missing-input), \ 136 echo >&2 "WARNING: $(missing-input) is missing."; \ 137 echo >&2 " Modules may not have dependencies or modversions."; \ 138 echo >&2 " You may get many unresolved symbol errors."; \ 139 echo >&2 " You can set KBUILD_MODPOST_WARN=1 to turn errors into warning"; \ 140 echo >&2 " if you want to proceed at your own risk.";) \ 141 $(MODPOST) $(modpost-args) 142 143targets += $(output-symdump) 144$(output-symdump): $(modpost-deps) FORCE 145 $(call if_changed,modpost) 146 147__modpost: $(output-symdump) 148PHONY += FORCE 149FORCE: 150 151existing-targets := $(wildcard $(sort $(targets))) 152 153-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) 154 155.PHONY: $(PHONY) 156