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