Linux kernel mirror (for testing)
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linux
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 per 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
35PHONY := __modpost
36__modpost:
37
38include include/config/auto.conf
39include $(srctree)/scripts/Kbuild.include
40
41modpost-args = \
42 $(if $(CONFIG_MODVERSIONS),-m) \
43 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
44 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
45 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
46 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \
47 -o $@
48
49# 'make -i -k' ignores compile errors, and builds as many modules as possible.
50ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
51modpost-args += -n
52endif
53
54ifeq ($(KBUILD_EXTMOD),)
55
56# Generate the list of in-tree objects in vmlinux
57# ---------------------------------------------------------------------------
58
59# This is used to retrieve symbol versions generated by genksyms.
60ifdef CONFIG_MODVERSIONS
61vmlinux.symvers Module.symvers: .vmlinux.objs
62endif
63
64# Ignore libgcc.a
65# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a
66# from the toolchain, but there is no EXPORT_SYMBOL in it.
67
68quiet_cmd_vmlinux_objs = GEN $@
69 cmd_vmlinux_objs = \
70 for f in $(real-prereqs); do \
71 case $${f} in \
72 *libgcc.a) ;; \
73 *) $(AR) t $${f} ;; \
74 esac \
75 done > $@
76
77targets += .vmlinux.objs
78.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
79 $(call if_changed,vmlinux_objs)
80
81vmlinux.o-if-present := $(wildcard vmlinux.o)
82output-symdump := vmlinux.symvers
83
84ifdef KBUILD_MODULES
85output-symdump := $(if $(vmlinux.o-if-present), Module.symvers, modules-only.symvers)
86missing-input := $(filter-out $(vmlinux.o-if-present),vmlinux.o)
87endif
88
89else
90
91# set src + obj - they may be used in the modules's Makefile
92obj := $(KBUILD_EXTMOD)
93src := $(obj)
94
95# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
96include $(or $(wildcard $(src)/Kbuild), $(src)/Makefile)
97
98module.symvers-if-present := $(wildcard Module.symvers)
99output-symdump := $(KBUILD_EXTMOD)/Module.symvers
100missing-input := $(filter-out $(module.symvers-if-present), Module.symvers)
101
102modpost-args += -e $(addprefix -i ,$(module.symvers-if-present) $(KBUILD_EXTRA_SYMBOLS))
103
104endif # ($(KBUILD_EXTMOD),)
105
106ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
107modpost-args += -w
108endif
109
110modorder-if-needed := $(if $(KBUILD_MODULES), $(MODORDER))
111
112MODPOST = scripts/mod/modpost
113
114# Read out modules.order to pass in modpost.
115# Otherwise, allmodconfig would fail with "Argument list too long".
116quiet_cmd_modpost = MODPOST $@
117 cmd_modpost = \
118 $(if $(missing-input), \
119 echo >&2 "WARNING: $(missing-input) is missing."; \
120 echo >&2 " Modules may not have dependencies or modversions."; \
121 echo >&2 " You may get many unresolved symbol warnings.";) \
122 sed 's/ko$$/o/' $(or $(modorder-if-needed), /dev/null) | $(MODPOST) $(modpost-args) -T - $(vmlinux.o-if-present)
123
124targets += $(output-symdump)
125$(output-symdump): $(modorder-if-needed) $(vmlinux.o-if-present) $(moudle.symvers-if-present) $(MODPOST) FORCE
126 $(call if_changed,modpost)
127
128__modpost: $(output-symdump)
129PHONY += FORCE
130FORCE:
131
132existing-targets := $(wildcard $(sort $(targets)))
133
134-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
135
136.PHONY: $(PHONY)