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