scripts/Makefile.modpost

   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 kernelsymfile := $(objtree)/Module.symvers
  47 modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
  48
  49 MODPOST = scripts/mod/modpost                                           \
  50         $(if $(CONFIG_MODVERSIONS),-m)                                  \
  51         $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a)                        \
  52         $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)                   \
  53         $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \
  54         $(if $(KBUILD_EXTMOD),-o $(modulesymfile))                      \
  55         $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)                  \
  56         $(if $(KBUILD_MODPOST_WARN),-w)
  57
  58 ifdef MODPOST_VMLINUX
  59
  60 quiet_cmd_modpost = MODPOST vmlinux.o
  61       cmd_modpost = $(MODPOST) vmlinux.o
  62
  63 __modpost:
  64         $(call cmd,modpost)
  65
  66 else
  67
  68 MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - \
  69         $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS))
  70
  71 ifeq ($(KBUILD_EXTMOD),)
  72 MODPOST += $(wildcard vmlinux)
  73 else
  74
  75 # set src + obj - they may be used in the modules's Makefile
  76 obj := $(KBUILD_EXTMOD)
  77 src := $(obj)
  78
  79 # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
  80 include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
  81              $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
  82 endif
  83
  84 # find all modules listed in modules.order
  85 modules := $(sort $(shell cat $(MODORDER)))
  86
  87 # Read out modules.order instead of expanding $(modules) to pass in modpost.
  88 # Otherwise, allmodconfig would fail with "Argument list too long".
  89 quiet_cmd_modpost = MODPOST $(words $(modules)) modules
  90       cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
  91
  92 __modpost:
  93         $(call cmd,modpost)
  94 ifneq ($(KBUILD_MODPOST_NOFINAL),1)
  95         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
  96 endif
  97
  98 endif
  99
 100 .PHONY: $(PHONY)