arch/x86/vdso/Makefile - arm/linux-arm64-legacy - Git at Google

 #
 # Building vDSO images for x86.
 #

 KBUILD_CFLAGS += $(DISABLE_LTO)

 VDSO64-$(CONFIG_X86_64)		:= y
 VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
 VDSO32-$(CONFIG_X86_32)		:= y
 VDSO32-$(CONFIG_COMPAT)		:= y

 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o

 # files to link into kernel
 obj-y				+= vma.o

 # vDSO images to build
 vdso_img-$(VDSO64-y)		+= 64
 vdso_img-$(VDSOX32-y)		+= x32
 vdso_img-$(VDSO32-y)		+= 32-int80
 vdso_img-$(CONFIG_COMPAT)	+= 32-syscall
 vdso_img-$(VDSO32-y)		+= 32-sysenter

 obj-$(VDSO32-y)			+= vdso32-setup.o

 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)

 $(obj)/vdso.o: $(obj)/vdso.so

 targets += vdso.lds $(vobjs-y)

 # Build the vDSO image C files and link them in.
 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
 vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
 vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
 obj-y += $(vdso_img_objs)
 targets += $(vdso_img_cfiles)
 targets += $(vdso_img_sodbg)
 .SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)

 export CPPFLAGS_vdso.lds += -P -C

 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
 			-Wl,--no-undefined \
 			-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
 			$(DISABLE_LTO)

 $(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
 	$(call if_changed,vdso)

 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
 hostprogs-y			+= vdso2c

 quiet_cmd_vdso2c = VDSO2C  $@
 define cmd_vdso2c
 	$(obj)/vdso2c $< $@
 endef

 $(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
 	$(call if_changed,vdso2c)

 #
 # Don't omit frame pointers for ease of userspace debugging, but do
 # optimize sibling calls.
 #
 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
        -fno-omit-frame-pointer -foptimize-sibling-calls \
        -DDISABLE_BRANCH_PROFILING

 $(vobjs): KBUILD_CFLAGS += $(CFL)

 #
 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
 #
 CFLAGS_REMOVE_vdso-note.o = -pg
 CFLAGS_REMOVE_vclock_gettime.o = -pg
 CFLAGS_REMOVE_vgetcpu.o = -pg
 CFLAGS_REMOVE_vvar.o = -pg

 #
 # X32 processes use x32 vDSO to access 64bit kernel data.
 #
 # Build x32 vDSO image:
 # 1. Compile x32 vDSO as 64bit.
 # 2. Convert object files to x32.
 # 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
 # so that it can reach 64bit address space with 64bit pointers.
 #

 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
 			   -Wl,-soname=linux-vdso.so.1 \
 			   -Wl,-z,max-page-size=4096 \
 			   -Wl,-z,common-page-size=4096

 # 64-bit objects to re-brand as x32
 vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))

 # x32-rebranded versions
 vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)

 # same thing, but in the output directory
 vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)

 # Convert 64bit object file to x32 for x32 vDSO.
 quiet_cmd_x32 = X32     $@
       cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@

 $(obj)/%-x32.o: $(obj)/%.o FORCE
 	$(call if_changed,x32)

 targets += vdsox32.lds $(vobjx32s-y)

 $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
 	$(call if_changed,vdso)

 #
 # Build multiple 32-bit vDSO images to choose from at boot time.
 #
 vdso32.so-$(VDSO32-y)		+= int80
 vdso32.so-$(CONFIG_COMPAT)	+= syscall
 vdso32.so-$(VDSO32-y)		+= sysenter

 vdso32-images			= $(vdso32.so-y:%=vdso32-%.so)

 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
 VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1

 # This makes sure the $(obj) subdirectory exists even though vdso32/
 # is not a kbuild sub-make subdirectory.
 override obj-dirs = $(dir $(obj)) $(obj)/vdso32/

 targets += vdso32/vdso32.lds
 targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
 targets += vdso32/vclock_gettime.o vdso32/vdso-fakesections.o

 $(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)

 KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
 $(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32

 KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
 KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
 KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
 KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
 KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 $(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)

 $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
 				 $(obj)/vdso32/vdso32.lds \
 				 $(obj)/vdso32/vclock_gettime.o \
 				 $(obj)/vdso32/vdso-fakesections.o \
 				 $(obj)/vdso32/note.o \
 				 $(obj)/vdso32/%.o
 	$(call if_changed,vdso)

 #
 # The DSO images are built using a special linker script.
 #
 quiet_cmd_vdso = VDSO    $@
       cmd_vdso = $(CC) -nostdlib -o $@ \
 		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
 		       -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
 		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'

 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
 	$(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
 GCOV_PROFILE := n

 #
 # Install the unstripped copies of vdso*.so.  If our toolchain supports
 # build-id, install .build-id links as well.
 #
 quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
 define cmd_vdso_install
 	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
 	if readelf -n $< |grep -q 'Build ID'; then \
 	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
 	  first=`echo $$buildid | cut -b-2`; \
 	  last=`echo $$buildid | cut -b3-`; \
 	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
 	  ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
 	fi
 endef

 vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)

 $(MODLIB)/vdso: FORCE
 	@mkdir -p $(MODLIB)/vdso

 $(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
 	$(call cmd,vdso_install)

 PHONY += vdso_install $(vdso_img_insttargets)
 vdso_install: $(vdso_img_insttargets) FORCE

 clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*
	#
	# Building vDSO images for x86.
	#

	KBUILD_CFLAGS += $(DISABLE_LTO)

	VDSO64-$(CONFIG_X86_64) := y
	VDSOX32-$(CONFIG_X86_X32_ABI) := y
	VDSO32-$(CONFIG_X86_32) := y
	VDSO32-$(CONFIG_COMPAT) := y

	# files to link into the vdso
	vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vdso-fakesections.o

	# files to link into kernel
	obj-y += vma.o

	# vDSO images to build
	vdso_img-$(VDSO64-y) += 64
	vdso_img-$(VDSOX32-y) += x32
	vdso_img-$(VDSO32-y) += 32-int80
	vdso_img-$(CONFIG_COMPAT) += 32-syscall
	vdso_img-$(VDSO32-y) += 32-sysenter

	obj-$(VDSO32-y) += vdso32-setup.o

	vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)

	$(obj)/vdso.o: $(obj)/vdso.so

	targets += vdso.lds $(vobjs-y)

	# Build the vDSO image C files and link them in.
	vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
	vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
	vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
	obj-y += $(vdso_img_objs)
	targets += $(vdso_img_cfiles)
	targets += $(vdso_img_sodbg)
	.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)

	export CPPFLAGS_vdso.lds += -P -C

	VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
	-Wl,--no-undefined \
	-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
	$(DISABLE_LTO)

	$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
	$(call if_changed,vdso)

	HOST_EXTRACFLAGS += -I$(srctree)/tools/include
	hostprogs-y += vdso2c

	quiet_cmd_vdso2c = VDSO2C $@
	define cmd_vdso2c
	$(obj)/vdso2c $< $@
	endef

	$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
	$(call if_changed,vdso2c)

	#
	# Don't omit frame pointers for ease of userspace debugging, but do
	# optimize sibling calls.
	#
	CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
	$(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
	-fno-omit-frame-pointer -foptimize-sibling-calls \
	-DDISABLE_BRANCH_PROFILING

	$(vobjs): KBUILD_CFLAGS += $(CFL)

	#
	# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
	#
	CFLAGS_REMOVE_vdso-note.o = -pg
	CFLAGS_REMOVE_vclock_gettime.o = -pg
	CFLAGS_REMOVE_vgetcpu.o = -pg
	CFLAGS_REMOVE_vvar.o = -pg

	#
	# X32 processes use x32 vDSO to access 64bit kernel data.
	#
	# Build x32 vDSO image:
	# 1. Compile x32 vDSO as 64bit.
	# 2. Convert object files to x32.
	# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
	# so that it can reach 64bit address space with 64bit pointers.
	#

	CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
	VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
	-Wl,-soname=linux-vdso.so.1 \
	-Wl,-z,max-page-size=4096 \
	-Wl,-z,common-page-size=4096

	# 64-bit objects to re-brand as x32
	vobjs64-for-x32 := $(filter-out $(vobjs-nox32),$(vobjs-y))

	# x32-rebranded versions
	vobjx32s-y := $(vobjs64-for-x32:.o=-x32.o)

	# same thing, but in the output directory
	vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)

	# Convert 64bit object file to x32 for x32 vDSO.
	quiet_cmd_x32 = X32 $@
	cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@

	$(obj)/%-x32.o: $(obj)/%.o FORCE
	$(call if_changed,x32)

	targets += vdsox32.lds $(vobjx32s-y)

	$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
	$(call if_changed,vdso)

	#
	# Build multiple 32-bit vDSO images to choose from at boot time.
	#
	vdso32.so-$(VDSO32-y) += int80
	vdso32.so-$(CONFIG_COMPAT) += syscall
	vdso32.so-$(VDSO32-y) += sysenter

	vdso32-images = $(vdso32.so-y:%=vdso32-%.so)

	CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
	VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1

	# This makes sure the $(obj) subdirectory exists even though vdso32/
	# is not a kbuild sub-make subdirectory.
	override obj-dirs = $(dir $(obj)) $(obj)/vdso32/

	targets += vdso32/vdso32.lds
	targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
	targets += vdso32/vclock_gettime.o vdso32/vdso-fakesections.o

	$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)

	KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS))
	$(vdso32-images:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
	$(vdso32-images:%=$(obj)/%.dbg): asflags-$(CONFIG_X86_64) += -m32

	KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
	KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
	KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
	KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
	KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
	KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
	KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
	KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
	KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
	$(vdso32-images:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)

	$(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
	$(obj)/vdso32/vdso32.lds \
	$(obj)/vdso32/vclock_gettime.o \
	$(obj)/vdso32/vdso-fakesections.o \
	$(obj)/vdso32/note.o \
	$(obj)/vdso32/%.o
	$(call if_changed,vdso)

	#
	# The DSO images are built using a special linker script.
	#
	quiet_cmd_vdso = VDSO $@
	cmd_vdso = $(CC) -nostdlib -o $@ \
	$(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
	-Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
	sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'

	VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
	$(call cc-ldoption, -Wl$(comma)--build-id) -Wl,-Bsymbolic $(LTO_CFLAGS)
	GCOV_PROFILE := n

	#
	# Install the unstripped copies of vdso*.so. If our toolchain supports
	# build-id, install .build-id links as well.
	#
	quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
	define cmd_vdso_install
	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
	if readelf -n $< \|grep -q 'Build ID'; then \
	buildid=`readelf -n $< \|grep 'Build ID' \|sed -e 's/^.Build ID: \(.\)$$/\1/'`; \
	first=`echo $$buildid \| cut -b-2`; \
	last=`echo $$buildid \| cut -b3-`; \
	mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
	ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
	fi
	endef

	vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)

	$(MODLIB)/vdso: FORCE
	@mkdir -p $(MODLIB)/vdso

	$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso FORCE
	$(call cmd,vdso_install)

	PHONY += vdso_install $(vdso_img_insttargets)
	vdso_install: $(vdso_img_insttargets) FORCE

	clean-files := vdso32-syscall* vdso32-sysenter* vdso32-int80*