| 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 | |
| 40 | PHONY := __modpost |
| 41 | __modpost: |
| 42 | |
| 43 | include include/config/auto.conf |
| 44 | include scripts/Kbuild.include |
| 45 | |
| 46 | MODPOST = scripts/mod/modpost \ |
| 47 | $(if $(CONFIG_MODVERSIONS),-m) \ |
| 48 | $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ |
| 49 | $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ |
| 50 | $(if $(KBUILD_MODPOST_WARN),-w) \ |
| 51 | -o $@ |
| 52 | |
| 53 | ifdef MODPOST_VMLINUX |
| 54 | |
| 55 | quiet_cmd_modpost = MODPOST $@ |
| 56 | cmd_modpost = $(MODPOST) $< |
| 57 | |
| 58 | vmlinux.symvers: vmlinux.o |
| 59 | $(call cmd,modpost) |
| 60 | |
| 61 | __modpost: vmlinux.symvers |
| 62 | |
| 63 | else |
| 64 | |
| 65 | ifeq ($(KBUILD_EXTMOD),) |
| 66 | |
| 67 | input-symdump := vmlinux.symvers |
| 68 | output-symdump := Module.symvers |
| 69 | |
| 70 | else |
| 71 | |
| 72 | # set src + obj - they may be used in the modules's Makefile |
| 73 | obj := $(KBUILD_EXTMOD) |
| 74 | src := $(obj) |
| 75 | |
| 76 | # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS |
| 77 | include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ |
| 78 | $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) |
| 79 | |
| 80 | # modpost option for external modules |
| 81 | MODPOST += -e |
| 82 | |
| 83 | input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS) |
| 84 | output-symdump := $(KBUILD_EXTMOD)/Module.symvers |
| 85 | |
| 86 | endif |
| 87 | |
| 88 | # modpost options for modules (both in-kernel and external) |
| 89 | MODPOST += \ |
| 90 | $(addprefix -i ,$(wildcard $(input-symdump))) \ |
| 91 | $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \ |
| 92 | $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) |
| 93 | |
| 94 | # 'make -i -k' ignores compile errors, and builds as many modules as possible. |
| 95 | ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) |
| 96 | MODPOST += -n |
| 97 | endif |
| 98 | |
| 99 | # Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree). |
| 100 | VPATH := |
| 101 | $(input-symdump): |
| 102 | @echo >&2 'WARNING: Symbol version dump "$@" is missing.' |
| 103 | @echo >&2 ' Modules may not have dependencies or modversions.' |
| 104 | |
| 105 | # Read out modules.order to pass in modpost. |
| 106 | # Otherwise, allmodconfig would fail with "Argument list too long". |
| 107 | quiet_cmd_modpost = MODPOST $@ |
| 108 | cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T - |
| 109 | |
| 110 | $(output-symdump): $(MODORDER) $(input-symdump) FORCE |
| 111 | $(call if_changed,modpost) |
| 112 | |
| 113 | targets += $(output-symdump) |
| 114 | |
| 115 | __modpost: $(output-symdump) |
| 116 | ifneq ($(KBUILD_MODPOST_NOFINAL),1) |
| 117 | $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal |
| 118 | endif |
| 119 | |
| 120 | PHONY += FORCE |
| 121 | FORCE: |
| 122 | |
| 123 | existing-targets := $(wildcard $(sort $(targets))) |
| 124 | |
| 125 | -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) |
| 126 | |
| 127 | endif |
| 128 | |
| 129 | .PHONY: $(PHONY) |