scripts/Makefile.modpost

   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 $(MODVERDIR)/
  13 # 2) modpost is then used to
  14 # 3)  create one <module>.mod.c file pr. module
  15 # 4)  create one Module.symvers file with CRC for all exported symbols
  16 # 5) compile all <module>.mod.c files
  17 # 6) final link of the module to a <module.ko> (or <module.unsigned>) file
  18 # 7) signs the modules to a <module.ko> file
  19
  20 # Step 3 is used to place certain information in the module's ELF
  21 # section, including information such as:
  22 #   Version magic (see include/linux/vermagic.h for full details)
  23 #     - Kernel release
  24 #     - SMP is CONFIG_SMP
  25 #     - PREEMPT is CONFIG_PREEMPT
  26 #     - GCC Version
  27 #   Module info
  28 #     - Module version (MODULE_VERSION)
  29 #     - Module alias'es (MODULE_ALIAS)
  30 #     - Module license (MODULE_LICENSE)
  31 #     - See include/linux/module.h for more details
  32
  33 # Step 4 is solely used to allow module versioning in external modules,
  34 # where the CRC of each module is retrieved from the Module.symvers file.
  35
  36 # Step 7 is dependent on CONFIG_MODULE_SIG being enabled.
  37
  38 # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined
  39 # symbols in the final module linking stage
  40 # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
  41 # This is solely useful to speed up test compiles
  42 PHONY := _modpost
  43 _modpost: __modpost
  44
  45 include include/config/auto.conf
  46 include scripts/Kbuild.include
  47
  48 # When building external modules load the Kbuild file to retrieve EXTRA_SYMBOLS info
  49 ifneq ($(KBUILD_EXTMOD),)
  50
  51 # set src + obj - they may be used when building the .mod.c file
  52 obj := $(KBUILD_EXTMOD)
  53 src := $(obj)
  54
  55 # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
  56 include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
  57              $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
  58 endif
  59
  60 include scripts/Makefile.lib
  61
  62 kernelsymfile := $(objtree)/Module.symvers
  63 modulesymfile := $(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)))
  67 modules   := $(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
  72 ifneq ($(KBUILD_BUILDHOST),$(ARCH))
  73         cross_build := 1
  74 endif
  75
  76 # Step 2), invoke modpost
  77 #  Includes step 3,4
  78 modpost = 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
  89 quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
  90       cmd_modpost = $(modpost) -s
  91
  92 PHONY += __modpost
  93 __modpost: $(modules:.ko=.o) FORCE
  94         $(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
  95
  96 quiet_cmd_kernel-mod = MODPOST $@
  97       cmd_kernel-mod = $(modpost) $@
  98
  99 vmlinux.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
 110 modname = $(notdir $(@:.mod.o=))
 111
 112 quiet_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
 119 targets += $(modules:.ko=.mod.o)
 120
 121 # Step 6), final link of the modules
 122 ifneq ($(CONFIG_MODULE_SIG),y)
 123 quiet_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
 131 targets += $(modules)
 132 else
 133 quiet_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
 143 targets += $(modules:.ko=.ko.unsigned)
 144
 145 # Step 7), sign the modules
 146 MODSECKEY = ./signing_key.priv
 147 MODPUBKEY = ./signing_key.x509
 148
 149 ifeq ($(wildcard $(MODSECKEY))+$(wildcard $(MODPUBKEY)),$(MODSECKEY)+$(MODPUBKEY))
 150 ifeq ($(KBUILD_SRC),)
 151         # no O= is being used
 152         SCRIPTS_DIR := scripts
 153 else
 154         SCRIPTS_DIR := $(KBUILD_SRC)/scripts
 155 endif
 156 SIGN_MODULES := 1
 157 else
 158 SIGN_MODULES := 0
 159 endif
 160
 161 # only sign if it's an in-tree module
 162 ifneq ($(KBUILD_EXTMOD),)
 163 SIGN_MODULES := 0
 164 endif
 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.
 168 EU_STRIP = $(shell which eu-strip || echo true)
 169
 170 quiet_cmd_sign_ko_stripped_ko_unsigned = STRIP [M] $@
 171       cmd_sign_ko_stripped_ko_unsigned = \
 172                 cp $< $@ && \
 173                 strip -x -g $@ && \
 174                 $(EU_STRIP) $@
 175
 176 ifeq ($(SIGN_MODULES),1)
 177
 178 quiet_cmd_genkeyid = GENKEYID $@
 179       cmd_genkeyid = \
 180                 perl $(SCRIPTS_DIR)/x509keyid $< $<.signer $<.keyid
 181
 182 %.signer %.keyid: %
 183         $(call if_changed,genkeyid)
 184
 185 KEYRING_DEP := $(MODSECKEY) $(MODPUBKEY) $(MODPUBKEY).signer $(MODPUBKEY).keyid
 186 quiet_cmd_sign_ko_ko_stripped = SIGN [M] $@
 187       cmd_sign_ko_ko_stripped = \
 188                 sh $(SCRIPTS_DIR)/sign-file $(MODSECKEY) $(MODPUBKEY) $< $@
 189 else
 190 KEYRING_DEP :=
 191 quiet_cmd_sign_ko_ko_unsigned = NO SIGN [M] $@
 192       cmd_sign_ko_ko_unsigned = \
 193                 cp $< $@
 194 endif
 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
 202 targets += $(modules)
 203 endif
 204
 205 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 206 # ---------------------------------------------------------------------------
 207
 208 PHONY += FORCE
 209
 210 FORCE:
 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
 217 targets := $(wildcard $(sort $(targets)))
 218 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
 219
 220 ifneq ($(cmd_files),)
 221   include $(cmd_files)
 222 endif
 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)