blob: cb21c173e15e82539547fd8b0730f6b60e45e5fd [file] [log] [blame] [edit]
# 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
mixed-build-prefix = $(if $(KBUILD_MIXED_TREE),$(KBUILD_MIXED_TREE)/)
modpost-args = \
$(if $(CONFIG_MODVERSIONS),-m) \
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \
-o $@
# 'make -i -k' ignores compile errors, and builds as many modules as possible.
ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
modpost-args += -n
endif
ifeq ($(CONFIG_MODULE_SCMVERSION),y)
ifeq ($(KBUILD_EXTMOD),)
module_srcpath := $(srctree)
else
# Get the external module's source path. KBUILD_EXTMOD could either be an
# absolute path or relative path from $(srctree). This makes sure that we
# aren't using a relative path from a separate working directory (O= or
# KBUILD_OUTPUT) since that may not be the actual module's SCM project path. So
# check the path relative to $(srctree) first.
ifneq ($(realpath $(srctree)/$(KBUILD_EXTMOD) 2>/dev/null),)
module_srcpath := $(srctree)/$(KBUILD_EXTMOD)
else
module_srcpath := $(KBUILD_EXTMOD)
endif
endif
# Get the SCM version of the module. Sed verifies setlocalversion returns
# a proper revision based on the SCM type, e.g. git, mercurial, or svn.
# Note: relative M= paths are not supported when building the kernel out of the
# srctree since setlocalversion won't be able to find the module srctree.
module_scmversion := $(shell $(srctree)/scripts/setlocalversion $(module_srcpath) | \
sed -n 's/.*-\(\(g\|hg\)[a-fA-F0-9]\+\(-dirty\)\?\|svn[0-9]\+\).*/\1/p')
ifneq ($(module_scmversion),)
modpost-args += -v $(module_scmversion)
endif
endif
ifeq ($(KBUILD_EXTMOD),)
# Generate the list of in-tree objects in vmlinux
# ---------------------------------------------------------------------------
# This is used to retrieve symbol versions generated by genksyms.
ifdef CONFIG_MODVERSIONS
ifndef KBUILD_MIXED_TREE
vmlinux.symvers Module.symvers: .vmlinux.objs
endif
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 > $@
quiet_cmd_vmlinux_symvers = GEN $@
cmd_vmlinux_symvers = grep "\<vmlinux\s\+EXPORT" $< > $@
quiet_cmd_cat_symvers = GEN $@
cmd_cat_symvers = cat $(real-prereqs) > $@
ifndef KBUILD_MIXED_TREE
targets += .vmlinux.objs
.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed,vmlinux_objs)
endif
vmlinux.o-if-present := $(wildcard vmlinux.o)
output-symdump := vmlinux.symvers
ifdef KBUILD_MODULES
output-symdump := $(if $(vmlinux.o-if-present), Module.symvers, modules-only.symvers)
missing-input := $(filter-out $(vmlinux.o-if-present),vmlinux.o)
targets += vmlinux.symvers
vmlinux.symvers: Module.symvers FORCE
$(call if_changed,vmlinux_symvers)
__modpost: $(if $(vmlinux.o-if-present),vmlinux.symvers,)
endif
# Overwrite values for mixed building (overwritting makes merges easier)
ifdef KBUILD_MIXED_TREE
targets += Module.symvers
Module.symvers: $(mixed-build-prefix)vmlinux.symvers modules-only.symvers FORCE
$(call if_changed,cat_symvers)
__modpost: Module.symvers
vmlinux.o-if-present :=
vmlinux.symvers-if-present := $(wildcard $(mixed-build-prefix)vmlinux.symvers)
modpost-args += $(addprefix -i ,$(vmlinux.symvers-if-present))
output-symdump := modules-only.symvers
missing-input := $(filter-out $(vmlinux.symvers-if-present),$(mixed-build-prefix)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 $(or $(wildcard $(src)/Kbuild), $(src)/Makefile)
module.symvers-if-present := $(wildcard Module.symvers)
output-symdump := $(KBUILD_EXTMOD)/Module.symvers
missing-input := $(filter-out $(module.symvers-if-present), Module.symvers)
modpost-args += -e $(addprefix -i ,$(module.symvers-if-present) $(KBUILD_EXTRA_SYMBOLS))
endif # ($(KBUILD_EXTMOD),)
ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
modpost-args += -w
endif
modorder-if-needed := $(if $(KBUILD_MODULES), $(MODORDER))
MODPOST = scripts/mod/modpost
# Read out modules.order to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
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 warnings.";) \
sed 's/ko$$/o/' $(or $(modorder-if-needed), /dev/null) | $(MODPOST) $(modpost-args) -T - $(vmlinux.o-if-present)
targets += $(output-symdump)
$(output-symdump): $(modorder-if-needed) $(vmlinux.o-if-present) $(module.symvers-if-present) $(MODPOST) 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)