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 = scripts/mod/modpost
42
43modpost-args = \
44 $(if $(CONFIG_MODVERSIONS),-m) \
45 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
46 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
47 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
48 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \
49 -o $@
50
51modpost-deps := $(MODPOST)
52
53# 'make -i -k' ignores compile errors, and builds as many modules as possible.
54ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
55modpost-args += -n
56endif
57
58ifeq ($(KBUILD_EXTMOD),)
59
60# Generate the list of in-tree objects in vmlinux
61# ---------------------------------------------------------------------------
62
63# This is used to retrieve symbol versions generated by genksyms.
64ifdef CONFIG_MODVERSIONS
65vmlinux.symvers Module.symvers: .vmlinux.objs
66endif
67
68# Ignore libgcc.a
69# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a
70# from the toolchain, but there is no EXPORT_SYMBOL in it.
71
72quiet_cmd_vmlinux_objs = GEN $@
73 cmd_vmlinux_objs = \
74 for f in $(real-prereqs); do \
75 case $${f} in \
76 *libgcc.a) ;; \
77 *) $(AR) t $${f} ;; \
78 esac \
79 done > $@
80
81targets += .vmlinux.objs
82.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
83 $(call if_changed,vmlinux_objs)
84
85ifeq ($(wildcard vmlinux.o),)
86missing-input := vmlinux.o
87output-symdump := modules-only.symvers
88else
89modpost-args += vmlinux.o
90modpost-deps += vmlinux.o
91output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers)
92endif
93
94else
95
96# set src + obj - they may be used in the modules's Makefile
97obj := $(KBUILD_EXTMOD)
98src := $(obj)
99
100# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
101include $(kbuild-file)
102
103output-symdump := $(KBUILD_EXTMOD)/Module.symvers
104
105ifeq ($(wildcard Module.symvers),)
106missing-input := Module.symvers
107else
108modpost-args += -i Module.symvers
109modpost-deps += Module.symvers
110endif
111
112modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))
113
114endif # ($(KBUILD_EXTMOD),)
115
116ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
117modpost-args += -w
118endif
119
120ifdef KBUILD_MODULES
121modpost-args += -T $(MODORDER)
122modpost-deps += $(MODORDER)
123endif
124
125# Read out modules.order to pass in modpost.
126# Otherwise, allmodconfig would fail with "Argument list too long".
127quiet_cmd_modpost = MODPOST $@
128 cmd_modpost = \
129 $(if $(missing-input), \
130 echo >&2 "WARNING: $(missing-input) is missing."; \
131 echo >&2 " Modules may not have dependencies or modversions."; \
132 echo >&2 " You may get many unresolved symbol warnings.";) \
133 $(MODPOST) $(modpost-args)
134
135targets += $(output-symdump)
136$(output-symdump): $(modpost-deps) FORCE
137 $(call if_changed,modpost)
138
139__modpost: $(output-symdump)
140PHONY += FORCE
141FORCE:
142
143existing-targets := $(wildcard $(sort $(targets)))
144
145-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
146
147.PHONY: $(PHONY)