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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
46MODPOST = scripts/mod/modpost \
47 $(if $(CONFIG_MODVERSIONS),-m) \
48 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
49 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
50 $(if $(KBUILD_MODPOST_WARN),-w) \
51 -o $@
52
53ifdef MODPOST_VMLINUX
54
55quiet_cmd_modpost = MODPOST $@
56 cmd_modpost = $(MODPOST) $<
57
58vmlinux.symvers: __KEEPMAKEFILEO__B.o
59 $(call cmd,modpost)
60
61__modpost: vmlinux.symvers
62
63else
64
65ifeq ($(KBUILD_EXTMOD),)
66
67input-symdump := vmlinux.symvers
68output-symdump := Module.symvers
69
70else
71
72# set src + obj - they may be used in the modules's Makefile
73obj := $(KBUILD_EXTMOD)
74src := $(obj)
75
76# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
77include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
78 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
79
80# modpost option for external modules
81MODPOST += -e
82
83input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
84output-symdump := $(KBUILD_EXTMOD)/Module.symvers
85
86endif
87
88# modpost options for modules (both in-kernel and external)
89MODPOST += \
90 $(addprefix -i ,$(wildcard $(input-symdump))) \
91 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
92 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)
93
94# 'make -i -k' ignores compile errors, and builds as many modules as possible.
95ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
96MODPOST += -n
97endif
98
99# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
100VPATH :=
101$(input-symdump):
102 @echo >&2 'WARNING: Symbol version dump "$@" is missing.'
103 @echo >&2 ' Modules may not have dependencies or modversions.'
104
105# Read out modules.order to pass in modpost.
106# Otherwise, allmodconfig would fail with "Argument list too long".
107quiet_cmd_modpost = MODPOST $@
108 cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T -
109
110$(output-symdump): $(MODORDER) $(input-symdump) FORCE
111 $(call if_changed,modpost)
112
113targets += $(output-symdump)
114
115__modpost: $(output-symdump)
116ifneq ($(KBUILD_MODPOST_NOFINAL),1)
117 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
118endif
119
120PHONY += FORCE
121FORCE:
122
123existing-targets := $(wildcard $(sort $(targets)))
124
125-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
126
127endif
128
129.PHONY: $(PHONY)
1# ===========================================================================
2# Module versions
3# ===========================================================================
4#
5# Stage one of module building created the following:
6# a) The individual .o files used for the module
7# b) A <module>.o file which is the .o files above linked together
8# c) A <module>.mod file in $(MODVERDIR)/, listing the name of the
9# the preliminary <module>.o file, plus all .o files
10
11# Stage 2 is handled by this file and does the following
12# 1) Find all modules from the files listed in $(MODVERDIR)/
13# 2) modpost is then used to
14# 3) create one <module>.mod.c file pr. module
15# 4) create one Module.symvers file with CRC for all exported symbols
16# 5) compile all <module>.mod.c files
17# 6) final link of the module to a <module.ko> file
18
19# Step 3 is used to place certain information in the module's ELF
20# section, including information such as:
21# Version magic (see include/linux/vermagic.h for full details)
22# - Kernel release
23# - SMP is CONFIG_SMP
24# - PREEMPT is CONFIG_PREEMPT
25# - GCC Version
26# Module info
27# - Module version (MODULE_VERSION)
28# - Module alias'es (MODULE_ALIAS)
29# - Module license (MODULE_LICENSE)
30# - See include/linux/module.h for more details
31
32# Step 4 is solely used to allow module versioning in external modules,
33# where the CRC of each module is retrieved from the Module.symvers file.
34
35# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
36# symbols in the final module linking stage
37# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
38# This is solely useful to speed up test compiles
39PHONY := _modpost
40_modpost: __modpost
41
42include include/config/auto.conf
43include scripts/Kbuild.include
44
45# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
46ifneq ($(KBUILD_EXTMOD),)
47
48# set src + obj - they may be used when building the .mod.c file
49obj := $(KBUILD_EXTMOD)
50src := $(obj)
51
52# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
53include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
54 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
55endif
56
57include scripts/Makefile.lib
58
59kernelsymfile := $(objtree)/Module.symvers
60modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
61
62# Step 1), find all modules listed in $(MODVERDIR)/
63__modules := $(sort $(shell grep -h '\.ko' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
64modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
65
66# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
67_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
68
69ifneq ($(KBUILD_BUILDHOST),$(ARCH))
70 cross_build := 1
71endif
72
73# Step 2), invoke modpost
74# Includes step 3,4
75modpost = scripts/mod/modpost \
76 $(if $(CONFIG_MODVERSIONS),-m) \
77 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
78 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
79 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
80 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
81 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
82 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
83 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
84 $(if $(cross_build),-c)
85
86quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
87 cmd_modpost = $(modpost) -s
88
89PHONY += __modpost
90__modpost: $(modules:.ko=.o) FORCE
91 $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
92
93quiet_cmd_kernel-mod = MODPOST $@
94 cmd_kernel-mod = $(modpost) $@
95
96vmlinux.o: FORCE
97 $(call cmd,kernel-mod)
98
99# Declare generated files as targets for modpost
100$(symverfile): __modpost ;
101$(modules:.ko=.mod.c): __modpost ;
102
103
104# Step 5), compile all *.mod.c files
105
106# modname is set to make c_flags define KBUILD_MODNAME
107modname = $(notdir $(@:.mod.o=))
108
109quiet_cmd_cc_o_c = CC $@
110 cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
111 -c -o $@ $<
112
113$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
114 $(call if_changed_dep,cc_o_c)
115
116targets += $(modules:.ko=.mod.o)
117
118# Step 6), final link of the modules
119quiet_cmd_ld_ko_o = LD [M] $@
120 cmd_ld_ko_o = $(LD) -r $(LDFLAGS) \
121 $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
122 -o $@ $(filter-out FORCE,$^)
123
124$(modules): %.ko :%.o %.mod.o FORCE
125 $(call if_changed,ld_ko_o)
126
127targets += $(modules)
128
129
130# Add FORCE to the prequisites of a target to force it to be always rebuilt.
131# ---------------------------------------------------------------------------
132
133PHONY += FORCE
134
135FORCE:
136
137# Read all saved command lines and dependencies for the $(targets) we
138# may be building above, using $(if_changed{,_dep}). As an
139# optimization, we don't need to read them if the target does not
140# exist, we will rebuild anyway in that case.
141
142targets := $(wildcard $(sort $(targets)))
143cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
144
145ifneq ($(cmd_files),)
146 include $(cmd_files)
147endif
148
149
150# Declare the contents of the .PHONY variable as phony. We keep that
151# information in a variable se we can use it in if_changed and friends.
152
153.PHONY: $(PHONY)