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# SPDX-License-Identifier: GPL-2.0
# ===========================================================================
# Module versions
# ===========================================================================
#
# Stage one of module building created the following:
# a) The individual .o files used for the module
# b) A <module>.o file which is the .o files above linked together
# c) A <module>.mod file, listing the name of the preliminary <module>.o file,
# plus all .o files
# d) modules.order, which lists all the modules
# Stage 2 is handled by this file and does the following
# 1) Find all modules listed in modules.order
# 2) modpost is then used to
# 3) create one <module>.mod.c file per module
# 4) create one Module.symvers file with CRC for all exported symbols
# Step 3 is used to place certain information in the module's ELF
# section, including information such as:
# Version magic (see include/linux/vermagic.h for full details)
# - Kernel release
# - SMP is CONFIG_SMP
# - PREEMPT is CONFIG_PREEMPT[_RT]
# - GCC Version
# Module info
# - Module version (MODULE_VERSION)
# - Module alias'es (MODULE_ALIAS)
# - Module license (MODULE_LICENSE)
# - See include/linux/module.h for more details
# Step 4 is solely used to allow module versioning in external modules,
# where the CRC of each module is retrieved from the Module.symvers file.
PHONY := __modpost
__modpost:
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
MODPOST = scripts/mod/modpost
modpost-args = \
$(if $(CONFIG_MODVERSIONS),-m) \
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
$(if $(KBUILD_MODPOST_WARN),-w) \
$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \
-o $@
modpost-deps := $(MODPOST)
# 'make -i -k' ignores compile errors, and builds as many modules as possible.
ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
modpost-args += -n
endif
# Read out modules.order to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
ifdef KBUILD_MODULES
modpost-args += -T $(MODORDER)
modpost-deps += $(MODORDER)
endif
ifeq ($(KBUILD_EXTMOD),)
# Generate the list of in-tree objects in vmlinux
# ---------------------------------------------------------------------------
# This is used to retrieve symbol versions generated by genksyms.
ifdef CONFIG_MODVERSIONS
vmlinux.symvers Module.symvers: .vmlinux.objs
endif
# Ignore libgcc.a
# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a
# from the toolchain, but there is no EXPORT_SYMBOL in it.
quiet_cmd_vmlinux_objs = GEN $@
cmd_vmlinux_objs = \
for f in $(real-prereqs); do \
case $${f} in \
*libgcc.a) ;; \
*) $(AR) t $${f} ;; \
esac \
done > $@
targets += .vmlinux.objs
.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed,vmlinux_objs)
ifeq ($(wildcard vmlinux.o),)
missing-input := vmlinux.o
output-symdump := modules-only.symvers
else
modpost-args += vmlinux.o
modpost-deps += vmlinux.o
output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers)
endif
else
# set src + obj - they may be used in the modules's Makefile
obj := $(KBUILD_EXTMOD)
src := $(obj)
# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
include $(kbuild-file)
output-symdump := $(KBUILD_EXTMOD)/Module.symvers
ifeq ($(wildcard Module.symvers),)
missing-input := Module.symvers
else
modpost-args += -i Module.symvers
modpost-deps += Module.symvers
endif
modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))
endif # ($(KBUILD_EXTMOD),)
quiet_cmd_modpost = MODPOST $@
cmd_modpost = \
$(if $(missing-input), \
echo >&2 "WARNING: $(missing-input) is missing."; \
echo >&2 " Modules may not have dependencies or modversions."; \
echo >&2 " You may get many unresolved symbol errors."; \
echo >&2 " You can set KBUILD_MODPOST_WARN=1 to turn errors into warning"; \
echo >&2 " if you want to proceed at your own risk.";) \
$(MODPOST) $(modpost-args)
targets += $(output-symdump)
$(output-symdump): $(modpost-deps) FORCE
$(call if_changed,modpost)
__modpost: $(output-symdump)
PHONY += FORCE
FORCE:
existing-targets := $(wildcard $(sort $(targets)))
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
.PHONY: $(PHONY)
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