1 # SPDX-License-Identifier: GPL-2.0 1 # SPDX-License-Identifier: GPL-2.0
2 # ============================================ 2 # ===========================================================================
3 # Module versions 3 # Module versions
4 # ============================================ 4 # ===========================================================================
5 # 5 #
6 # Stage one of module building created the fol 6 # Stage one of module building created the following:
7 # a) The individual .o files used for the modu 7 # a) The individual .o files used for the module
8 # b) A <module>.o file which is the .o files a 8 # b) A <module>.o file which is the .o files above linked together
9 # c) A <module>.mod file, listing the name of 9 # c) A <module>.mod file, listing the name of the preliminary <module>.o file,
10 # plus all .o files 10 # plus all .o files
11 # d) modules.order, which lists all the module 11 # d) modules.order, which lists all the modules
12 12
13 # Stage 2 is handled by this file and does the 13 # Stage 2 is handled by this file and does the following
14 # 1) Find all modules listed in modules.order 14 # 1) Find all modules listed in modules.order
15 # 2) modpost is then used to 15 # 2) modpost is then used to
16 # 3) create one <module>.mod.c file per modul !! 16 # 3) create one <module>.mod.c file pr. module
17 # 4) create one Module.symvers file with CRC 17 # 4) create one Module.symvers file with CRC for all exported symbols
>> 18 # 5) compile all <module>.mod.c files
>> 19 # 6) final link of the module to a <module.ko> file
18 20
19 # Step 3 is used to place certain information 21 # Step 3 is used to place certain information in the module's ELF
20 # section, including information such as: 22 # section, including information such as:
21 # Version magic (see include/linux/vermagic. 23 # Version magic (see include/linux/vermagic.h for full details)
22 # - Kernel release 24 # - Kernel release
23 # - SMP is CONFIG_SMP 25 # - SMP is CONFIG_SMP
24 # - PREEMPT is CONFIG_PREEMPT[_RT] !! 26 # - PREEMPT is CONFIG_PREEMPT
25 # - GCC Version 27 # - GCC Version
26 # Module info 28 # Module info
27 # - Module version (MODULE_VERSION) 29 # - Module version (MODULE_VERSION)
28 # - Module alias'es (MODULE_ALIAS) 30 # - Module alias'es (MODULE_ALIAS)
29 # - Module license (MODULE_LICENSE) 31 # - Module license (MODULE_LICENSE)
30 # - See include/linux/module.h for more de 32 # - See include/linux/module.h for more details
31 33
32 # Step 4 is solely used to allow module versio 34 # Step 4 is solely used to allow module versioning in external modules,
33 # where the CRC of each module is retrieved fr 35 # where the CRC of each module is retrieved from the Module.symvers file.
34 36
>> 37 # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
>> 38 # symbols in the final module linking stage
>> 39 # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
>> 40 # This is solely useful to speed up test compiles
>> 41
35 PHONY := __modpost 42 PHONY := __modpost
36 __modpost: 43 __modpost:
37 44
38 include include/config/auto.conf 45 include include/config/auto.conf
39 include $(srctree)/scripts/Kbuild.include !! 46 include scripts/Kbuild.include
40 <<
41 MODPOST = scripts/mod/modpost <<
42 47
43 modpost-args = !! 48 kernelsymfile := $(objtree)/Module.symvers
44 $(if $(CONFIG_MODULES),-M) !! 49 modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
45 $(if $(CONFIG_MODVERSIONS),-m) <<
46 $(if $(CONFIG_MODULE_SRCVERSION_ALL),- <<
47 $(if $(CONFIG_SECTION_MISMATCH_WARN_ON <<
48 $(if $(KBUILD_MODPOST_WARN),-w) <<
49 $(if $(KBUILD_NSDEPS),-d $(MODULES_NSD <<
50 $(if $(CONFIG_MODULE_ALLOW_MISSING_NAM <<
51 $(if $(findstring 1, $(KBUILD_EXTRA_WA <<
52 -o $@ <<
53 <<
54 modpost-deps := $(MODPOST) <<
55 <<
56 # 'make -i -k' ignores compile errors, and bui <<
57 ifneq ($(findstring i,$(filter-out --%,$(MAKEF <<
58 modpost-args += -n <<
59 endif <<
60 50
61 # Read out modules.order to pass in modpost. !! 51 MODPOST = scripts/mod/modpost \
62 # Otherwise, allmodconfig would fail with "Arg !! 52 $(if $(CONFIG_MODVERSIONS),-m) \
63 ifdef KBUILD_MODULES !! 53 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
64 modpost-args += -T $(MODORDER) !! 54 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
65 modpost-deps += $(MODORDER) !! 55 $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
66 endif !! 56 $(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS))) \
>> 57 $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
>> 58 $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
>> 59 $(if $(KBUILD_MODPOST_WARN),-w)
67 60
68 ifeq ($(KBUILD_EXTMOD),) !! 61 ifdef MODPOST_VMLINUX
69 62
70 # Generate the list of in-tree objects in vmli !! 63 __modpost: vmlinux.o
71 # -------------------------------------------- <<
72 64
73 # This is used to retrieve symbol versions gen !! 65 quiet_cmd_modpost = MODPOST $@
74 ifdef CONFIG_MODVERSIONS !! 66 cmd_modpost = $(MODPOST) $@
75 vmlinux.symvers Module.symvers: .vmlinux.objs <<
76 endif <<
77 67
78 # Ignore libgcc.a !! 68 PHONY += vmlinux.o
79 # Some architectures do '$(CC) --print-libgcc- !! 69 vmlinux.o:
80 # from the toolchain, but there is no EXPORT_S !! 70 $(call cmd,modpost)
81 <<
82 quiet_cmd_vmlinux_objs = GEN $@ <<
83 cmd_vmlinux_objs = \ <<
84 for f in $(real-prereqs); do \ <<
85 case $${f} in \ <<
86 *libgcc.a) ;; \ <<
87 *) $(AR) t $${f} ;; \ <<
88 esac \ <<
89 done > $@ <<
90 <<
91 targets += .vmlinux.objs <<
92 .vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS <<
93 $(call if_changed,vmlinux_objs) <<
94 <<
95 ifdef CONFIG_TRIM_UNUSED_KSYMS <<
96 ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST) <<
97 ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$ <<
98 modpost-args += -t $(addprefix -u , $(ksym-wl) <<
99 modpost-deps += $(ksym-wl) <<
100 endif <<
101 71
102 ifeq ($(wildcard vmlinux.o),) <<
103 missing-input := vmlinux.o <<
104 output-symdump := modules-only.symvers <<
105 else 72 else
106 modpost-args += vmlinux.o <<
107 modpost-deps += vmlinux.o <<
108 output-symdump := $(if $(KBUILD_MODULES), Modu <<
109 endif <<
110 73
111 else !! 74 # When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
>> 75 ifneq ($(KBUILD_EXTMOD),)
112 76
113 # set src + obj - they may be used in the modu !! 77 # set src + obj - they may be used when building the .mod.c file
114 obj := $(KBUILD_EXTMOD) 78 obj := $(KBUILD_EXTMOD)
115 src := $(if $(VPATH),$(VPATH)/)$(obj) !! 79 src := $(obj)
116 80
117 # Include the module's Makefile to find KBUILD 81 # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
118 include $(kbuild-file) !! 82 include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
>> 83 $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
>> 84 endif
119 85
120 output-symdump := $(KBUILD_EXTMOD)/Module.symv !! 86 include scripts/Makefile.lib
121 87
122 ifeq ($(wildcard Module.symvers),) !! 88 # find all modules listed in modules.order
123 missing-input := Module.symvers !! 89 modules := $(sort $(shell cat $(MODORDER)))
124 else <<
125 modpost-args += -i Module.symvers <<
126 modpost-deps += Module.symvers <<
127 endif <<
128 90
129 modpost-args += -e $(addprefix -i , $(KBUILD_E !! 91 # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
>> 92 __modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
>> 93 @:
130 94
131 endif # ($(KBUILD_EXTMOD),) !! 95 MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - $(wildcard vmlinux)
132 96
133 quiet_cmd_modpost = MODPOST $@ !! 97 # We can go over command line length here, so be careful.
134 cmd_modpost = \ !! 98 quiet_cmd_modpost = MODPOST $(words $(modules)) modules
135 $(if $(missing-input), \ !! 99 cmd_modpost = sed 's/ko$$/o/' $(MODORDER) | $(MODPOST)
136 echo >&2 "WARNING: $(missing-i !! 100
137 echo >&2 " Modules may !! 101 PHONY += modules-modpost
138 echo >&2 " You may get !! 102 modules-modpost:
139 echo >&2 " You can set !! 103 $(call cmd,modpost)
140 echo >&2 " if you want !! 104
141 $(MODPOST) $(modpost-args) !! 105 # Declare generated files as targets for modpost
142 !! 106 $(modules:.ko=.mod.c): modules-modpost
143 targets += $(output-symdump) !! 107
144 $(output-symdump): $(modpost-deps) FORCE !! 108 # Step 5), compile all *.mod.c files
145 $(call if_changed,modpost) !! 109
>> 110 # modname is set to make c_flags define KBUILD_MODNAME
>> 111 modname = $(notdir $(@:.mod.o=))
>> 112
>> 113 quiet_cmd_cc_o_c = CC $@
>> 114 cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
>> 115 -c -o $@ $<
>> 116
>> 117 $(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
>> 118 $(call if_changed_dep,cc_o_c)
>> 119
>> 120 targets += $(modules:.ko=.mod.o)
>> 121
>> 122 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
>> 123
>> 124 # Step 6), final link of the modules with optional arch pass after final link
>> 125 quiet_cmd_ld_ko_o = LD [M] $@
>> 126 cmd_ld_ko_o = \
>> 127 $(LD) -r $(KBUILD_LDFLAGS) \
>> 128 $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
>> 129 -o $@ $(real-prereqs) ; \
>> 130 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
>> 131
>> 132 $(modules): %.ko :%.o %.mod.o FORCE
>> 133 +$(call if_changed,ld_ko_o)
>> 134
>> 135 targets += $(modules)
>> 136
>> 137
>> 138 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
>> 139 # ---------------------------------------------------------------------------
146 140
147 __modpost: $(output-symdump) <<
148 PHONY += FORCE 141 PHONY += FORCE
>> 142
149 FORCE: 143 FORCE:
150 144
>> 145 # Read all saved command lines and dependencies for the $(targets) we
>> 146 # may be building above, using $(if_changed{,_dep}). As an
>> 147 # optimization, we don't need to read them if the target does not
>> 148 # exist, we will rebuild anyway in that case.
>> 149
151 existing-targets := $(wildcard $(sort $(target 150 existing-targets := $(wildcard $(sort $(targets)))
152 151
153 -include $(foreach f,$(existing-targets),$(dir 152 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
>> 153
>> 154 endif
154 155
155 .PHONY: $(PHONY) 156 .PHONY: $(PHONY)
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