arch/arm64/kernel/vdso32/Makefile - linux - Git at Google

 # SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for vdso32
 #

 # Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
 # the inclusion of generic Makefile.
 ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32
 include $(srctree)/lib/vdso/Makefile

 # Same as cc-*option, but using CC_COMPAT instead of CC
 ifeq ($(CONFIG_CC_IS_CLANG), y)
 COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
 COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)

 CC_COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
 CC_COMPAT_CLANG_FLAGS += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE_COMPAT))
 CC_COMPAT_CLANG_FLAGS += -no-integrated-as -Qunused-arguments
 ifneq ($(COMPAT_GCC_TOOLCHAIN),)
 CC_COMPAT_CLANG_FLAGS += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
 endif

 CC_COMPAT ?= $(CC)
 CC_COMPAT += $(CC_COMPAT_CLANG_FLAGS)

 ifneq ($(LLVM),)
 LD_COMPAT ?= $(LD)
 else
 LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
 endif
 else
 CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
 LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
 endif

 cc32-option = $(call try-run,\
         $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 cc32-disable-warning = $(call try-run,\
 	$(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
 cc32-as-instr = $(call try-run,\
 	printf "%b\n" "$(1)" | $(CC_COMPAT) $(VDSO_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))

 # We cannot use the global flags to compile the vDSO files, the main reason
 # being that the 32-bit compiler may be older than the main (64-bit) compiler
 # and therefore may not understand flags set using $(cc-option ...). Besides,
 # arch-specific options should be taken from the arm Makefile instead of the
 # arm64 one.
 # As a result we set our own flags here.

 # KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile
 VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc -isystem $(shell $(CC_COMPAT) -print-file-name=include)
 VDSO_CPPFLAGS += $(LINUXINCLUDE)

 # Common C and assembly flags
 # From top-level Makefile
 VDSO_CAFLAGS := $(VDSO_CPPFLAGS)
 ifneq ($(shell $(CC_COMPAT) --version 2>&1 | head -n 1 | grep clang),)
 VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
 endif

 VDSO_CAFLAGS += $(call cc32-option,-fno-PIE)
 ifdef CONFIG_DEBUG_INFO
 VDSO_CAFLAGS += -g
 endif

 # From arm Makefile
 VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm)
 VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft
 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
 VDSO_CAFLAGS += -mbig-endian
 else
 VDSO_CAFLAGS += -mlittle-endian
 endif

 # From arm vDSO Makefile
 VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector
 VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING


 # Try to compile for ARMv8. If the compiler is too old and doesn't support it,
 # fall back to v7. There is no easy way to check for what architecture the code
 # is being compiled, so define a macro specifying that (see arch/arm/Makefile).
 VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\
                                    -march=armv7-a -D__LINUX_ARM_ARCH__=7)

 VDSO_CFLAGS := $(VDSO_CAFLAGS)
 VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
 # KBUILD_CFLAGS from top-level Makefile
 VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
                -fno-strict-aliasing -fno-common \
                -Werror-implicit-function-declaration \
                -Wno-format-security \
                -std=gnu89
 VDSO_CFLAGS  += -O2
 # Some useful compiler-dependent flags from top-level Makefile
 VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
 VDSO_CFLAGS += -fno-strict-overflow
 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
 VDSO_CFLAGS += -Werror=date-time
 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)

 # The 32-bit compiler does not provide 128-bit integers, which are used in
 # some headers that are indirectly included from the vDSO code.
 # This hack makes the compiler happy and should trigger a warning/error if
 # variables of such type are referenced.
 VDSO_CFLAGS += -D__uint128_t='void*'
 # Silence some warnings coming from headers that operate on long's
 # (on GCC 4.8 or older, there is unfortunately no way to silence this warning)
 VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow)
 VDSO_CFLAGS += -Wno-int-to-pointer-cast

 # Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is
 # unreliable.
 ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y)
 VDSO_CFLAGS += -mthumb -fomit-frame-pointer
 else
 VDSO_CFLAGS += -marm
 endif

 VDSO_AFLAGS := $(VDSO_CAFLAGS)
 VDSO_AFLAGS += -D__ASSEMBLY__

 # Check for binutils support for dmb ishld
 dmbinstr := $(call cc32-as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1)

 VDSO_CFLAGS += $(dmbinstr)
 VDSO_AFLAGS += $(dmbinstr)

 # From arm vDSO Makefile
 VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1
 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
 VDSO_LDFLAGS += -nostdlib -shared --hash-style=sysv --build-id=sha1


 # Borrow vdsomunge.c from the arm vDSO
 # We have to use a relative path because scripts/Makefile.host prefixes
 # $(hostprogs) with $(obj)
 munge := ../../../arm/vdso/vdsomunge
 hostprogs := $(munge)

 c-obj-vdso := note.o
 c-obj-vdso-gettimeofday := vgettimeofday.o

 ifneq ($(c-gettimeofday-y),)
 VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y)
 endif

 VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os

 # Build rules
 targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw
 c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso))
 c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday))
 asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso))
 obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)

 targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)

 # Force dependency (vdso.s includes vdso.so through incbin)
 $(obj)/vdso.o: $(obj)/vdso.so

 include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE
 	$(call if_changed,vdsosym)

 # Strip rule for vdso.so
 $(obj)/vdso.so: OBJCOPYFLAGS := -S
 $(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
 	$(call if_changed,objcopy)

 $(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE
 	$(call if_changed,vdsomunge)

 # Link rule for the .so file, .lds has to be first
 $(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
 	$(call if_changed,vdsold_and_vdso_check)

 # Compilation rules for the vDSO sources
 $(c-obj-vdso): %.o: %.c FORCE
 	$(call if_changed_dep,vdsocc)
 $(c-obj-vdso-gettimeofday): %.o: %.c FORCE
 	$(call if_changed_dep,vdsocc_gettimeofday)
 $(asm-obj-vdso): %.o: %.S FORCE
 	$(call if_changed_dep,vdsoas)

 # Actual build commands
 quiet_cmd_vdsold_and_vdso_check = LD32    $@
       cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check)

 quiet_cmd_vdsold = LD32    $@
       cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS) \
                    -T $(filter %.lds,$^) $(filter %.o,$^) -o $@
 quiet_cmd_vdsocc = CC32    $@
       cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $<
 quiet_cmd_vdsocc_gettimeofday = CC32    $@
       cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $<
 quiet_cmd_vdsoas = AS32    $@
       cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $<

 quiet_cmd_vdsomunge = MUNGE   $@
       cmd_vdsomunge = $(obj)/$(munge) $< $@

 # Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO)
 gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh
 quiet_cmd_vdsosym = VDSOSYM $@
 # The AArch64 nm should be able to read an AArch32 binary
       cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@

 # Install commands for the unstripped file
 quiet_cmd_vdso_install = INSTALL32 $@
       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so

 vdso.so: $(obj)/vdso.so.dbg
 	@mkdir -p $(MODLIB)/vdso
 	$(call cmd,vdso_install)

 vdso_install: vdso.so
	# SPDX-License-Identifier: GPL-2.0
	#
	# Makefile for vdso32
	#

	# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
	# the inclusion of generic Makefile.
	ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT\|R_ARM_GLOB_DAT\|R_ARM_ABS32
	include $(srctree)/lib/vdso/Makefile

	# Same as cc-*option, but using CC_COMPAT instead of CC
	ifeq ($(CONFIG_CC_IS_CLANG), y)
	COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
	COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)

	CC_COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
	CC_COMPAT_CLANG_FLAGS += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE_COMPAT))
	CC_COMPAT_CLANG_FLAGS += -no-integrated-as -Qunused-arguments
	ifneq ($(COMPAT_GCC_TOOLCHAIN),)
	CC_COMPAT_CLANG_FLAGS += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
	endif

	CC_COMPAT ?= $(CC)
	CC_COMPAT += $(CC_COMPAT_CLANG_FLAGS)

	ifneq ($(LLVM),)
	LD_COMPAT ?= $(LD)
	else
	LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
	endif
	else
	CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
	LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
	endif

	cc32-option = $(call try-run,\
	$(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
	cc32-disable-warning = $(call try-run,\
	$(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
	cc32-as-instr = $(call try-run,\
	printf "%b\n" "$(1)" \| $(CC_COMPAT) $(VDSO_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))

	# We cannot use the global flags to compile the vDSO files, the main reason
	# being that the 32-bit compiler may be older than the main (64-bit) compiler
	# and therefore may not understand flags set using $(cc-option ...). Besides,
	# arch-specific options should be taken from the arm Makefile instead of the
	# arm64 one.
	# As a result we set our own flags here.

	# KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile
	VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc -isystem $(shell $(CC_COMPAT) -print-file-name=include)
	VDSO_CPPFLAGS += $(LINUXINCLUDE)

	# Common C and assembly flags
	# From top-level Makefile
	VDSO_CAFLAGS := $(VDSO_CPPFLAGS)
	ifneq ($(shell $(CC_COMPAT) --version 2>&1 \| head -n 1 \| grep clang),)
	VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
	endif

	VDSO_CAFLAGS += $(call cc32-option,-fno-PIE)
	ifdef CONFIG_DEBUG_INFO
	VDSO_CAFLAGS += -g
	endif

	# From arm Makefile
	VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm)
	VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft
	ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
	VDSO_CAFLAGS += -mbig-endian
	else
	VDSO_CAFLAGS += -mlittle-endian
	endif

	# From arm vDSO Makefile
	VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector
	VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING


	# Try to compile for ARMv8. If the compiler is too old and doesn't support it,
	# fall back to v7. There is no easy way to check for what architecture the code
	# is being compiled, so define a macro specifying that (see arch/arm/Makefile).
	VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\
	-march=armv7-a -D__LINUX_ARM_ARCH__=7)

	VDSO_CFLAGS := $(VDSO_CAFLAGS)
	VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
	# KBUILD_CFLAGS from top-level Makefile
	VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
	-fno-strict-aliasing -fno-common \
	-Werror-implicit-function-declaration \
	-Wno-format-security \
	-std=gnu89
	VDSO_CFLAGS += -O2
	# Some useful compiler-dependent flags from top-level Makefile
	VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
	VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
	VDSO_CFLAGS += -fno-strict-overflow
	VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
	VDSO_CFLAGS += -Werror=date-time
	VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)

	# The 32-bit compiler does not provide 128-bit integers, which are used in
	# some headers that are indirectly included from the vDSO code.
	# This hack makes the compiler happy and should trigger a warning/error if
	# variables of such type are referenced.
	VDSO_CFLAGS += -D__uint128_t='void*'
	# Silence some warnings coming from headers that operate on long's
	# (on GCC 4.8 or older, there is unfortunately no way to silence this warning)
	VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow)
	VDSO_CFLAGS += -Wno-int-to-pointer-cast

	# Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is
	# unreliable.
	ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y)
	VDSO_CFLAGS += -mthumb -fomit-frame-pointer
	else
	VDSO_CFLAGS += -marm
	endif

	VDSO_AFLAGS := $(VDSO_CAFLAGS)
	VDSO_AFLAGS += -D__ASSEMBLY__

	# Check for binutils support for dmb ishld
	dmbinstr := $(call cc32-as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1)

	VDSO_CFLAGS += $(dmbinstr)
	VDSO_AFLAGS += $(dmbinstr)

	# From arm vDSO Makefile
	VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1
	VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
	VDSO_LDFLAGS += -nostdlib -shared --hash-style=sysv --build-id=sha1


	# Borrow vdsomunge.c from the arm vDSO
	# We have to use a relative path because scripts/Makefile.host prefixes
	# $(hostprogs) with $(obj)
	munge := ../../../arm/vdso/vdsomunge
	hostprogs := $(munge)

	c-obj-vdso := note.o
	c-obj-vdso-gettimeofday := vgettimeofday.o

	ifneq ($(c-gettimeofday-y),)
	VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y)
	endif

	VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os

	# Build rules
	targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw
	c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso))
	c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday))
	asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso))
	obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)

	targets += vdso.lds
	CPPFLAGS_vdso.lds += -P -C -U$(ARCH)

	# Force dependency (vdso.s includes vdso.so through incbin)
	$(obj)/vdso.o: $(obj)/vdso.so

	include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE
	$(call if_changed,vdsosym)

	# Strip rule for vdso.so
	$(obj)/vdso.so: OBJCOPYFLAGS := -S
	$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
	$(call if_changed,objcopy)

	$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE
	$(call if_changed,vdsomunge)

	# Link rule for the .so file, .lds has to be first
	$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
	$(call if_changed,vdsold_and_vdso_check)

	# Compilation rules for the vDSO sources
	$(c-obj-vdso): %.o: %.c FORCE
	$(call if_changed_dep,vdsocc)
	$(c-obj-vdso-gettimeofday): %.o: %.c FORCE
	$(call if_changed_dep,vdsocc_gettimeofday)
	$(asm-obj-vdso): %.o: %.S FORCE
	$(call if_changed_dep,vdsoas)

	# Actual build commands
	quiet_cmd_vdsold_and_vdso_check = LD32 $@
	cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check)

	quiet_cmd_vdsold = LD32 $@
	cmd_vdsold = $(LD_COMPAT) $(VDSO_LDFLAGS) \
	-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
	quiet_cmd_vdsocc = CC32 $@
	cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $<
	quiet_cmd_vdsocc_gettimeofday = CC32 $@
	cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $<
	quiet_cmd_vdsoas = AS32 $@
	cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $<

	quiet_cmd_vdsomunge = MUNGE $@
	cmd_vdsomunge = $(obj)/$(munge) $< $@

	# Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO)
	gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh
	quiet_cmd_vdsosym = VDSOSYM $@
	# The AArch64 nm should be able to read an AArch32 binary
	cmd_vdsosym = $(NM) $< \| $(gen-vdsosym) \| LC_ALL=C sort > $@

	# Install commands for the unstripped file
	quiet_cmd_vdso_install = INSTALL32 $@
	cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so

	vdso.so: $(obj)/vdso.so.dbg
	@mkdir -p $(MODLIB)/vdso
	$(call cmd,vdso_install)

	vdso_install: vdso.so