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_NOFINAL can be set to skip the final link of modules.
 36# This is solely useful to speed up test compiles
 37
 38PHONY := __modpost
 39__modpost:
 40
 41include include/config/auto.conf
 42include $(srctree)/scripts/Kbuild.include
 43
 44# for ld_flags
 45include $(srctree)/scripts/Makefile.lib
 46
 47MODPOST = scripts/mod/modpost								\
 48	$(if $(CONFIG_MODVERSIONS),-m)							\
 49	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a)					\
 50	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)					\
 51	-o $@
 
 
 
 
 
 52
 53ifdef MODPOST_VMLINUX
 54
 55quiet_cmd_modpost = MODPOST $@
 56      cmd_modpost = $(MODPOST) $<
 57
 58vmlinux.symvers: __KEEPMAKEFILEO__B.o
 59	$(call cmd,modpost)
 60
 61__modpost: vmlinux.symvers
 62
 63else
 64
 65ifeq ($(KBUILD_EXTMOD),)
 66
 67input-symdump := vmlinux.symvers
 68output-symdump := modules-only.symvers
 69
 70quiet_cmd_cat = GEN     $@
 71      cmd_cat = cat $(real-prereqs) > $@
 72
 73ifneq ($(wildcard vmlinux.symvers),)
 74
 75__modpost: Module.symvers
 76Module.symvers: vmlinux.symvers modules-only.symvers FORCE
 77	$(call if_changed,cat)
 78
 79targets += Module.symvers
 80
 81endif
 82
 83else
 84
 85# set src + obj - they may be used in the modules's Makefile
 86obj := $(KBUILD_EXTMOD)
 87src := $(obj)
 88
 89# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
 90include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
 91             $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
 92
 93# modpost option for external modules
 94MODPOST += -e
 95
 96input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
 97output-symdump := $(KBUILD_EXTMOD)/Module.symvers
 98
 99endif
100
101existing-input-symdump := $(wildcard $(input-symdump))
102
103# modpost options for modules (both in-kernel and external)
104MODPOST += \
105	$(addprefix -i ,$(existing-input-symdump)) \
106	$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
107	$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)
108
109# 'make -i -k' ignores compile errors, and builds as many modules as possible.
110ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
111MODPOST += -n
112endif
113
114# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
115VPATH :=
116$(input-symdump):
117	@echo >&2 'WARNING: Symbol version dump "$@" is missing.'
118	@echo >&2 '         Modules may not have dependencies or modversions.'
119	@echo >&2 '         You may get many unresolved symbol warnings.'
120
121ifdef CONFIG_LTO_CLANG
122# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run
123# LTO to compile them into native code before running modpost
124prelink-ext := .lto
125
126quiet_cmd_cc_lto_link_modules = LTO [M] $@
127cmd_cc_lto_link_modules =						\
128	$(LD) $(ld_flags) -r -o $@					\
129		$(shell [ -s $(@:.lto.o=.o.symversions) ] &&		\
130			echo -T $(@:.lto.o=.o.symversions))		\
131		--whole-archive $^
132
133%.lto.o: %.o
134	$(call if_changed,cc_lto_link_modules)
135endif
136
 
137modules := $(sort $(shell cat $(MODORDER)))
138
139# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols
140ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),)
141MODPOST += -w
142endif
143
144# Read out modules.order to pass in modpost.
145# Otherwise, allmodconfig would fail with "Argument list too long".
146quiet_cmd_modpost = MODPOST $@
147      cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T -
148
149$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE
150	$(call if_changed,modpost)
151
152targets += $(output-symdump)
153
154__modpost: $(output-symdump)
155ifneq ($(KBUILD_MODPOST_NOFINAL),1)
156	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
157endif
158
159PHONY += FORCE
160FORCE:
161
162existing-targets := $(wildcard $(sort $(targets)))
163
164-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
165
166endif
167
168.PHONY: $(PHONY)

  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
 40PHONY := __modpost
 41__modpost:
 42
 43include include/config/auto.conf
 44include scripts/Kbuild.include
 45
 46kernelsymfile := $(objtree)/Module.symvers
 47modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
 48
 49MODPOST = 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),-I $(modulesymfile))			\
 54	$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS)))	\
 55	$(if $(KBUILD_EXTMOD),-o $(modulesymfile))			\
 56	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)			\
 57	$(if $(KBUILD_MODPOST_WARN),-w)					\
 58	$(if $(filter nsdeps,$(MAKECMDGOALS)),-d)
 59
 60ifdef MODPOST_VMLINUX
 61
 62quiet_cmd_modpost = MODPOST vmlinux.o
 63      cmd_modpost = $(MODPOST) vmlinux.o
 64
 65__modpost:
 66	$(call cmd,modpost)
 67
 
 
 68else
 69
 70# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
 71ifneq ($(KBUILD_EXTMOD),)
 
 
 
 
 
 
 
 
 
 
 
 
 
 72
 73# set src + obj - they may be used when building the .mod.c file
 
 
 
 
 74obj := $(KBUILD_EXTMOD)
 75src := $(obj)
 76
 77# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
 78include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
 79             $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
 
 
 
 
 
 
 
 80endif
 81
 82MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 83
 84# find all modules listed in modules.order
 85modules := $(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".
 89quiet_cmd_modpost = MODPOST $(words $(modules)) modules
 90      cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
 91
 92__modpost:
 93	@$(kecho) '  Building modules, stage 2.'
 94	$(call cmd,modpost)
 
 
 
 95ifneq ($(KBUILD_MODPOST_NOFINAL),1)
 96	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
 97endif
 98
 99nsdeps: __modpost
 
 
 
 
 
100
101endif
102
103.PHONY: $(PHONY)