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