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