blob: b7c50cb48ba4f4682368c526d3158d5e0b49c35a
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 $(MODVERDIR)/ |
13 | # 2) modpost is then used to |
14 | # 3) create one <module>.mod.c file pr. module |
15 | # 4) create one Module.symvers file with CRC for all exported symbols |
16 | # 5) compile all <module>.mod.c files |
17 | # 6) final link of the module to a <module.ko> file |
18 | |
19 | # Step 3 is used to place certain information in the module's ELF |
20 | # section, including information such as: |
21 | # Version magic (see include/linux/vermagic.h for full details) |
22 | # - Kernel release |
23 | # - SMP is CONFIG_SMP |
24 | # - PREEMPT is CONFIG_PREEMPT |
25 | # - GCC Version |
26 | # Module info |
27 | # - Module version (MODULE_VERSION) |
28 | # - Module alias'es (MODULE_ALIAS) |
29 | # - Module license (MODULE_LICENSE) |
30 | # - See include/linux/module.h for more details |
31 | |
32 | # Step 4 is solely used to allow module versioning in external modules, |
33 | # where the CRC of each module is retrieved from the Module.symvers file. |
34 | |
35 | # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined |
36 | # symbols in the final module linking stage |
37 | # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. |
38 | # This is solely useful to speed up test compiles |
39 | PHONY := _modpost |
40 | _modpost: __modpost |
41 | |
42 | include include/config/auto.conf |
43 | include scripts/Kbuild.include |
44 | |
45 | # When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info |
46 | ifneq ($(KBUILD_EXTMOD),) |
47 | |
48 | # set src + obj - they may be used when building the .mod.c file |
49 | obj := $(KBUILD_EXTMOD) |
50 | src := $(obj) |
51 | |
52 | # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS |
53 | include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ |
54 | $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) |
55 | endif |
56 | |
57 | include scripts/Makefile.lib |
58 | |
59 | kernelsymfile := $(objtree)/Module.symvers |
60 | modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers |
61 | |
62 | # Step 1), find all modules listed in $(MODVERDIR)/ |
63 | MODLISTCMD := find $(MODVERDIR) -name '*.mod' | xargs -r grep -h '\.ko$$' | sort -u |
64 | __modules := $(shell $(MODLISTCMD)) |
65 | modules := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o))) |
66 | |
67 | # Stop after building .o files if NOFINAL is set. Makes compile tests quicker |
68 | _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules)) |
69 | |
70 | # Step 2), invoke modpost |
71 | # Includes step 3,4 |
72 | modpost = scripts/mod/modpost \ |
73 | $(if $(CONFIG_MODVERSIONS),-m) \ |
74 | $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \ |
75 | $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \ |
76 | $(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \ |
77 | $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \ |
78 | $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ |
79 | $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \ |
80 | $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ |
81 | $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) |
82 | |
83 | MODPOST_OPT=$(subst -i,-n,$(filter -i,$(MAKEFLAGS))) |
84 | |
85 | # If CONFIG_LTO_CLANG is enabled, .o files are either LLVM IR, or empty, so we |
86 | # need to link them into actual objects before passing them to modpost |
87 | modpost-ext = $(if $(CONFIG_LTO_CLANG),.lto,) |
88 | |
89 | ifdef CONFIG_LTO_CLANG |
90 | quiet_cmd_cc_lto_link_modules = LD [M] $@ |
91 | cmd_cc_lto_link_modules = \ |
92 | $(LD) $(ld_flags) -r -o $(@) \ |
93 | $(shell [ -s $(@:$(modpost-ext).o=.o.symversions) ] && \ |
94 | echo -T $(@:$(modpost-ext).o=.o.symversions)) \ |
95 | --whole-archive $(filter-out FORCE,$^) |
96 | |
97 | $(modules:.ko=$(modpost-ext).o): %$(modpost-ext).o: %.o FORCE |
98 | $(call if_changed,cc_lto_link_modules) |
99 | endif |
100 | |
101 | # We can go over command line length here, so be careful. |
102 | quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules |
103 | cmd_modpost = $(MODLISTCMD) | sed 's/\.ko$$/$(modpost-ext)\.o/' | $(modpost) $(MODPOST_OPT) -s -T - |
104 | |
105 | PHONY += __modpost |
106 | __modpost: $(modules:.ko=$(modpost-ext).o) FORCE |
107 | $(call cmd,modpost) $(wildcard vmlinux) |
108 | |
109 | quiet_cmd_kernel-mod = MODPOST $@ |
110 | cmd_kernel-mod = $(modpost) $@ |
111 | |
112 | vmlinux.o: FORCE |
113 | $(call cmd,kernel-mod) |
114 | |
115 | # Declare generated files as targets for modpost |
116 | $(symverfile): __modpost ; |
117 | $(modules:.ko=$(modpost-ext).mod.c): __modpost ; |
118 | |
119 | # Step 5), compile all *.mod.c files |
120 | |
121 | # modname is set to make c_flags define KBUILD_MODNAME |
122 | modname = $(notdir $(@:.mod.o=)) |
123 | |
124 | quiet_cmd_cc_o_c = CC $@ |
125 | cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \ |
126 | -c -o $@ $< |
127 | |
128 | $(modules:.ko=.mod.o): %.mod.o: %$(modpost-ext).mod.c FORCE |
129 | $(call if_changed_dep,cc_o_c) |
130 | |
131 | targets += $(modules:.ko=$(modpost-ext).mod.o) |
132 | |
133 | ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink) |
134 | |
135 | # Step 6), final link of the modules with optional arch pass after final link |
136 | quiet_cmd_ld_ko_o = LD [M] $@ |
137 | |
138 | ifdef CONFIG_LTO_CLANG |
139 | cmd_ld_ko_o = \ |
140 | $(LD) -r $(LDFLAGS) \ |
141 | $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \ |
142 | $(shell [ -s $(@:.ko=.o.symversions) ] && \ |
143 | echo -T $(@:.ko=.o.symversions)) \ |
144 | -o $@ --whole-archive \ |
145 | $(filter-out FORCE,$(^:$(modpost-ext).o=.o)) |
146 | |
147 | ifdef CONFIG_FTRACE_MCOUNT_RECORD |
148 | cmd_ld_ko_o += ; $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) $@ |
149 | endif |
150 | else |
151 | cmd_ld_ko_o = \ |
152 | $(LD) -r $(LDFLAGS) \ |
153 | $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \ |
154 | -o $@ $(filter-out FORCE,$^) ; \ |
155 | $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) |
156 | endif |
157 | |
158 | $(modules): %.ko: %$(modpost-ext).o %.mod.o FORCE |
159 | +$(call if_changed,ld_ko_o) |
160 | |
161 | targets += $(modules) |
162 | |
163 | |
164 | # Add FORCE to the prequisites of a target to force it to be always rebuilt. |
165 | # --------------------------------------------------------------------------- |
166 | |
167 | PHONY += FORCE |
168 | |
169 | FORCE: |
170 | |
171 | # Read all saved command lines and dependencies for the $(targets) we |
172 | # may be building above, using $(if_changed{,_dep}). As an |
173 | # optimization, we don't need to read them if the target does not |
174 | # exist, we will rebuild anyway in that case. |
175 | |
176 | targets := $(wildcard $(sort $(targets))) |
177 | cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) |
178 | |
179 | ifneq ($(cmd_files),) |
180 | include $(cmd_files) |
181 | endif |
182 | |
183 | |
184 | # Declare the contents of the .PHONY variable as phony. We keep that |
185 | # information in a variable se we can use it in if_changed and friends. |
186 | |
187 | .PHONY: $(PHONY) |
188 |