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