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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_NOFINAL can be set to skip the final link of modules.
36# This is solely useful to speed up test compiles
37
38PHONY := __modpost
39__modpost:
40
41include include/config/auto.conf
42include $(srctree)/scripts/Kbuild.include
43
44# for ld_flags
45include $(srctree)/scripts/Makefile.lib
46
47MODPOST = scripts/mod/modpost \
48 $(if $(CONFIG_MODVERSIONS),-m) \
49 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
50 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
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 := modules-only.symvers
69
70quiet_cmd_cat = GEN $@
71 cmd_cat = cat $(real-prereqs) > $@
72
73ifneq ($(wildcard vmlinux.symvers),)
74
75__modpost: Module.symvers
76Module.symvers: vmlinux.symvers modules-only.symvers FORCE
77 $(call if_changed,cat)
78
79targets += Module.symvers
80
81endif
82
83else
84
85# set src + obj - they may be used in the modules's Makefile
86obj := $(KBUILD_EXTMOD)
87src := $(obj)
88
89# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
90include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
91 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
92
93# modpost option for external modules
94MODPOST += -e
95
96input-symdump := Module.symvers $(KBUILD_EXTRA_SYMBOLS)
97output-symdump := $(KBUILD_EXTMOD)/Module.symvers
98
99endif
100
101existing-input-symdump := $(wildcard $(input-symdump))
102
103# modpost options for modules (both in-kernel and external)
104MODPOST += \
105 $(addprefix -i ,$(existing-input-symdump)) \
106 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
107 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N)
108
109# 'make -i -k' ignores compile errors, and builds as many modules as possible.
110ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
111MODPOST += -n
112endif
113
114# Clear VPATH to not search for *.symvers in $(srctree). Check only $(objtree).
115VPATH :=
116$(input-symdump):
117 @echo >&2 'WARNING: Symbol version dump "$@" is missing.'
118 @echo >&2 ' Modules may not have dependencies or modversions.'
119 @echo >&2 ' You may get many unresolved symbol warnings.'
120
121ifdef CONFIG_LTO_CLANG
122# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run
123# LTO to compile them into native code before running modpost
124prelink-ext := .lto
125
126quiet_cmd_cc_lto_link_modules = LTO [M] $@
127cmd_cc_lto_link_modules = \
128 $(LD) $(ld_flags) -r -o $@ \
129 $(shell [ -s $(@:.lto.o=.o.symversions) ] && \
130 echo -T $(@:.lto.o=.o.symversions)) \
131 --whole-archive $^
132
133%.lto.o: %.o
134 $(call if_changed,cc_lto_link_modules)
135endif
136
137modules := $(sort $(shell cat $(MODORDER)))
138
139# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined symbols
140ifneq ($(KBUILD_MODPOST_WARN)$(filter-out $(existing-input-symdump), $(input-symdump)),)
141MODPOST += -w
142endif
143
144# Read out modules.order to pass in modpost.
145# Otherwise, allmodconfig would fail with "Argument list too long".
146quiet_cmd_modpost = MODPOST $@
147 cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T -
148
149$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE
150 $(call if_changed,modpost)
151
152targets += $(output-symdump)
153
154__modpost: $(output-symdump)
155ifneq ($(KBUILD_MODPOST_NOFINAL),1)
156 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
157endif
158
159PHONY += FORCE
160FORCE:
161
162existing-targets := $(wildcard $(sort $(targets)))
163
164-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
165
166endif
167
168.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)/
63MODLISTCMD := find $(MODVERDIR) -name '*.mod' | xargs -r grep -h '\.ko$$' | sort -u
64__modules := $(shell $(MODLISTCMD))
65modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
66
67# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
68_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
69
70# Step 2), invoke modpost
71# Includes step 3,4
72modpost = scripts/mod/modpost \
73 $(if $(CONFIG_MODVERSIONS),-m) \
74 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
75 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
76 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
77 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
78 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
79 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
80 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
81 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
82
83MODPOST_OPT=$(subst -i,-n,$(filter -i,$(MAKEFLAGS)))
84
85# We can go over command line length here, so be careful.
86quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
87 cmd_modpost = $(MODLISTCMD) | sed 's/\.ko$$/.o/' | $(modpost) $(MODPOST_OPT) -s -T -
88
89PHONY += __modpost
90__modpost: $(modules:.ko=.o) FORCE
91 $(call cmd,modpost) $(wildcard vmlinux)
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)