aboutsummaryrefslogtreecommitdiffstats
path: root/scripts/Makefile.modpost
blob: 002089141df448fa569688a3e5e57b130d68e88b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
# ===========================================================================
# Module versions
# ===========================================================================
#
# Stage one of module building created the following:
# a) The individual .o files used for the module
# b) A <module>.o file which is the .o files above linked together
# c) A <module>.mod file in $(MODVERDIR)/, listing the name of the
#    the preliminary <module>.o file, plus all .o files

# Stage 2 is handled by this file and does the following
# 1) Find all modules from the files listed in $(MODVERDIR)/
# 2) modpost is then used to
# 3)  create one <module>.mod.c file pr. module
# 4)  create one Module.symvers file with CRC for all exported symbols
# 5) compile all <module>.mod.c files
# 6) final link of the module to a <module.ko> (or <module.unsigned>) file
# 7) signs the modules to a <module.ko> file

# Step 3 is used to place certain information in the module's ELF
# section, including information such as:
#   Version magic (see include/linux/vermagic.h for full details)
#     - Kernel release
#     - SMP is CONFIG_SMP
#     - PREEMPT is CONFIG_PREEMPT
#     - GCC Version
#   Module info
#     - Module version (MODULE_VERSION)
#     - Module alias'es (MODULE_ALIAS)
#     - Module license (MODULE_LICENSE)
#     - See include/linux/module.h for more details

# Step 4 is solely used to allow module versioning in external modules,
# where the CRC of each module is retrieved from the Module.symvers file.

# Step 7 is dependent on CONFIG_MODULE_SIG being enabled.

# KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
# symbols in the final module linking stage
# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
# This is solely useful to speed up test compiles
PHONY := _modpost
_modpost: __modpost

include include/config/auto.conf
include scripts/Kbuild.include

# When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
ifneq ($(KBUILD_EXTMOD),)

# set src + obj - they may be used when building the .mod.c file
obj := $(KBUILD_EXTMOD)
src := $(obj)

# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
             $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
endif

include scripts/Makefile.lib

kernelsymfile := $(objtree)/Module.symvers
modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers

# Step 1), find all modules listed in $(MODVERDIR)/
__modules := $(sort $(shell grep -h '\.ko$$' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
modules   := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))

# Stop after building .o files if NOFINAL is set. Makes compile tests quicker
_modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))

ifneq ($(KBUILD_BUILDHOST),$(ARCH))
        cross_build := 1
endif

# Step 2), invoke modpost
#  Includes step 3,4
modpost = scripts/mod/modpost                    \
 $(if $(CONFIG_MODVERSIONS),-m)                  \
 $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,)       \
 $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)   \
 $(if $(KBUILD_EXTMOD),-I $(modulesymfile))      \
 $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
 $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
 $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \
 $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
 $(if $(cross_build),-c)

quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
      cmd_modpost = $(modpost) -s

PHONY += __modpost
__modpost: $(modules:.ko=.o) FORCE
	$(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)

quiet_cmd_kernel-mod = MODPOST $@
      cmd_kernel-mod = $(modpost) $@

vmlinux.o: FORCE
	$(call cmd,kernel-mod)

# Declare generated files as targets for modpost
$(symverfile):         __modpost ;
$(modules:.ko=.mod.c): __modpost ;


# Step 5), compile all *.mod.c files

# modname is set to make c_flags define KBUILD_MODNAME
modname = $(notdir $(@:.mod.o=))

quiet_cmd_cc_o_c = CC      $@
      cmd_cc_o_c = $(CC) $(c_flags) $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE) \
		   -c -o $@ $<

$(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE
	$(call if_changed_dep,cc_o_c)

targets += $(modules:.ko=.mod.o)

# Step 6), final link of the modules
ifneq ($(CONFIG_MODULE_SIG),y)
quiet_cmd_ld_ko_o = LD [M]  $@
      cmd_ld_ko_o = $(LD) -r $(LDFLAGS)                                 \
                             $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
                             -o $@ $(filter-out FORCE,$^)

$(modules): %.ko :%.o %.mod.o FORCE
	$(call if_changed,ld_ko_o)

targets += $(modules)
else
quiet_cmd_ld_ko_unsigned_o = LD [M]  $@
      cmd_ld_ko_unsigned_o =						\
		$(LD) -r $(LDFLAGS)					\
			 $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE)	\
			 -o $@ $(filter-out FORCE,$^)			\
		$(if $(AFTER_LINK),; $(AFTER_LINK))

$(modules:.ko=.ko.unsigned): %.ko.unsigned :%.o %.mod.o FORCE
	$(call if_changed,ld_ko_unsigned_o)

targets += $(modules:.ko=.ko.unsigned)

# Step 7), sign the modules
MODSECKEY = ./signing_key.priv
MODPUBKEY = ./signing_key.x509

ifeq ($(wildcard $(MODSECKEY))+$(wildcard $(MODPUBKEY)),$(MODSECKEY)+$(MODPUBKEY))
ifeq ($(KBUILD_SRC),)
	# no O= is being used
	SCRIPTS_DIR := scripts
else
	SCRIPTS_DIR := $(KBUILD_SRC)/scripts
endif
SIGN_MODULES := 1
else
SIGN_MODULES := 0
endif

# only sign if it's an in-tree module
ifneq ($(KBUILD_EXTMOD),)
SIGN_MODULES := 0
endif

# We strip the module as best we can - note that using both strip and eu-strip
# results in a smaller module than using either alone.
EU_STRIP = $(shell which eu-strip || echo true)

quiet_cmd_sign_ko_stripped_ko_unsigned = STRIP [M] $@
      cmd_sign_ko_stripped_ko_unsigned = \
		cp $< $@ && \
		strip -x -g $@ && \
		$(EU_STRIP) $@

ifeq ($(SIGN_MODULES),1)

quiet_cmd_genkeyid = GENKEYID $@
      cmd_genkeyid = \
		perl $(SCRIPTS_DIR)/x509keyid $< $<.signer $<.keyid

%.signer %.keyid: %
	$(call if_changed,genkeyid)

KEYRING_DEP := $(MODSECKEY) $(MODPUBKEY) $(MODPUBKEY).signer $(MODPUBKEY).keyid
quiet_cmd_sign_ko_ko_stripped = SIGN [M] $@
      cmd_sign_ko_ko_stripped = \
		sh $(SCRIPTS_DIR)/sign-file $(MODSECKEY) $(MODPUBKEY) $< $@
else
KEYRING_DEP :=
quiet_cmd_sign_ko_ko_unsigned = NO SIGN [M] $@
      cmd_sign_ko_ko_unsigned = \
		cp $< $@
endif

$(modules): %.ko :%.ko.stripped $(KEYRING_DEP) FORCE
	$(call if_changed,sign_ko_ko_stripped)

$(patsubst %.ko,%.ko.stripped,$(modules)): %.ko.stripped :%.ko.unsigned FORCE
	$(call if_changed,sign_ko_stripped_ko_unsigned)

targets += $(modules)
endif

# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------

PHONY += FORCE

FORCE:

# Read all saved command lines and dependencies for the $(targets) we
# may be building above, using $(if_changed{,_dep}). As an
# optimization, we don't need to read them if the target does not
# exist, we will rebuild anyway in that case.

targets := $(wildcard $(sort $(targets)))
cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))

ifneq ($(cmd_files),)
  include $(cmd_files)
endif


# Declare the contents of the .PHONY variable as phony.  We keep that
# information in a variable se we can use it in if_changed and friends.

.PHONY: $(PHONY)