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