xref: /linux-6.15/scripts/Makefile.modpost (revision e1858b2a) 
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 $(MODVERDIR)/
13# 2) modpost is then used to
14# 3)  create one <module>.mod.c file pr. module
15# 4)  create one Module.symvers file with CRC for all exported symbols
16# 5) compile all <module>.mod.c files
17# 6) final link of the module to a <module.ko> (or <module.unsigned>) file
18# 7) signs the modules to a <module.ko> file
19
20# Step 3 is used to place certain information in the module's ELF
21# section, including information such as:
22#   Version magic (see include/linux/vermagic.h for full details)
23#     - Kernel release
24#     - SMP is CONFIG_SMP
25#     - PREEMPT is CONFIG_PREEMPT
26#     - GCC Version
27#   Module info
28#     - Module version (MODULE_VERSION)
29#     - Module alias'es (MODULE_ALIAS)
30#     - Module license (MODULE_LICENSE)
31#     - See include/linux/module.h for more details
32
33# Step 4 is solely used to allow module versioning in external modules,
34# where the CRC of each module is retrieved from the Module.symvers file.
35
36# Step 7 is dependent on CONFIG_MODULE_SIG being enabled.
37
38# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
39# symbols in the final module linking stage
40# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
41# This is solely useful to speed up test compiles
42PHONY := _modpost
43_modpost: __modpost
44
45include include/config/auto.conf
46include scripts/Kbuild.include
47
48# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
49ifneq ($(KBUILD_EXTMOD),)
50
51# set src + obj - they may be used when building the .mod.c file
52obj := $(KBUILD_EXTMOD)
53src := $(obj)
54
55# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
56include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
57             $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
58endif
59
60include scripts/Makefile.lib
61
62kernelsymfile := $(objtree)/Module.symvers
63modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers
64
65# Step 1), find all modules listed in $(MODVERDIR)/
66__modules := $(sort $(shell grep -h '\.ko$$' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
67modules   := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
68
69# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
70_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
71
72ifneq ($(KBUILD_BUILDHOST),$(ARCH))
73        cross_build := 1
74endif
75
76# Step 2), invoke modpost
77#  Includes step 3,4
78modpost = scripts/mod/modpost                    \
79 $(if $(CONFIG_MODVERSIONS),-m)                  \
80 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,)       \
81 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)   \
82 $(if $(KBUILD_EXTMOD),-I $(modulesymfile))      \
83 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
84 $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
85 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \
86 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
87 $(if $(cross_build),-c)
88
89quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
90      cmd_modpost = $(modpost) -s
91
92PHONY += __modpost
93__modpost: $(modules:.ko=.o) FORCE
94	$(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
95
96quiet_cmd_kernel-mod = MODPOST $@
97      cmd_kernel-mod = $(modpost) $@
98
99vmlinux.o: FORCE
100	$(call cmd,kernel-mod)
101
102# Declare generated files as targets for modpost
103$(symverfile):         __modpost ;
104$(modules:.ko=.mod.c): __modpost ;
105
106
107# Step 5), compile all *.mod.c files
108
109# modname is set to make c_flags define KBUILD_MODNAME
110modname = $(notdir $(@:.mod.o=))
111
112quiet_cmd_cc_o_c = CC      $@
113      cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
114		   -c -o $@ $<
115
116$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
117	$(call if_changed_dep,cc_o_c)
118
119targets += $(modules:.ko=.mod.o)
120
121# Step 6), final link of the modules
122ifneq ($(CONFIG_MODULE_SIG),y)
123quiet_cmd_ld_ko_o = LD [M]  $@
124      cmd_ld_ko_o = $(LD) -r $(LDFLAGS)                                 \
125                             $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
126                             -o $@ $(filter-out FORCE,$^)
127
128$(modules): %.ko :%.o %.mod.o FORCE
129	$(call if_changed,ld_ko_o)
130
131targets += $(modules)
132else
133quiet_cmd_ld_ko_unsigned_o = LD [M]  $@
134      cmd_ld_ko_unsigned_o =						\
135		$(LD) -r $(LDFLAGS)					\
136			 $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE)	\
137			 -o $@ $(filter-out FORCE,$^)			\
138		$(if $(AFTER_LINK),; $(AFTER_LINK))
139
140$(modules:.ko=.ko.unsigned): %.ko.unsigned :%.o %.mod.o FORCE
141	$(call if_changed,ld_ko_unsigned_o)
142
143targets += $(modules:.ko=.ko.unsigned)
144
145# Step 7), sign the modules
146MODSECKEY = ./signing_key.priv
147MODPUBKEY = ./signing_key.x509
148
149ifeq ($(wildcard $(MODSECKEY))+$(wildcard $(MODPUBKEY)),$(MODSECKEY)+$(MODPUBKEY))
150ifeq ($(KBUILD_SRC),)
151	# no O= is being used
152	SCRIPTS_DIR := scripts
153else
154	SCRIPTS_DIR := $(KBUILD_SRC)/scripts
155endif
156SIGN_MODULES := 1
157else
158SIGN_MODULES := 0
159endif
160
161# only sign if it's an in-tree module
162ifneq ($(KBUILD_EXTMOD),)
163SIGN_MODULES := 0
164endif
165
166# We strip the module as best we can - note that using both strip and eu-strip
167# results in a smaller module than using either alone.
168EU_STRIP = $(shell which eu-strip || echo true)
169
170quiet_cmd_sign_ko_stripped_ko_unsigned = STRIP [M] $@
171      cmd_sign_ko_stripped_ko_unsigned = \
172		cp $< $@ && \
173		strip -x -g $@ && \
174		$(EU_STRIP) $@
175
176ifeq ($(SIGN_MODULES),1)
177
178quiet_cmd_genkeyid = GENKEYID $@
179      cmd_genkeyid = \
180		perl $(SCRIPTS_DIR)/x509keyid $< $<.signer $<.keyid
181
182%.signer %.keyid: %
183	$(call if_changed,genkeyid)
184
185KEYRING_DEP := $(MODSECKEY) $(MODPUBKEY) $(MODPUBKEY).signer $(MODPUBKEY).keyid
186quiet_cmd_sign_ko_ko_stripped = SIGN [M] $@
187      cmd_sign_ko_ko_stripped = \
188		sh $(SCRIPTS_DIR)/sign-file $(MODSECKEY) $(MODPUBKEY) $< $@
189else
190KEYRING_DEP :=
191quiet_cmd_sign_ko_ko_unsigned = NO SIGN [M] $@
192      cmd_sign_ko_ko_unsigned = \
193		cp $< $@
194endif
195
196$(modules): %.ko :%.ko.stripped $(KEYRING_DEP) FORCE
197	$(call if_changed,sign_ko_ko_stripped)
198
199$(patsubst %.ko,%.ko.stripped,$(modules)): %.ko.stripped :%.ko.unsigned FORCE
200	$(call if_changed,sign_ko_stripped_ko_unsigned)
201
202targets += $(modules)
203endif
204
205# Add FORCE to the prequisites of a target to force it to be always rebuilt.
206# ---------------------------------------------------------------------------
207
208PHONY += FORCE
209
210FORCE:
211
212# Read all saved command lines and dependencies for the $(targets) we
213# may be building above, using $(if_changed{,_dep}). As an
214# optimization, we don't need to read them if the target does not
215# exist, we will rebuild anyway in that case.
216
217targets := $(wildcard $(sort $(targets)))
218cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
219
220ifneq ($(cmd_files),)
221  include $(cmd_files)
222endif
223
224
225# Declare the contents of the .PHONY variable as phony.  We keep that
226# information in a variable se we can use it in if_changed and friends.
227
228.PHONY: $(PHONY)
229