linux/arch/mips/vdso/Makefile
Vincenzo Frascino cdab7e2c73
mips: vdso: Fix flip/flop vdso building bug
Running "make" on an already compiled kernel tree will rebuild the
vdso library even if this has not been modified.

$ make
  GEN     Makefile
  Using linux as source for kernel
  CALL   linux/scripts/atomic/check-atomics.sh
  CALL   linux/scripts/checksyscalls.sh
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
  CHK     include/generated/compile.h
  VDSO    arch/mips/vdso/vdso.so.dbg.raw
  OBJCOPY arch/mips/vdso/vdso.so.raw
  GENVDSO arch/mips/vdso/vdso-image.c
  CC      arch/mips/vdso/vdso-image.o
  AR      arch/mips/vdso/built-in.a
  AR      arch/mips/built-in.a
  CHK     include/generated/autoksyms.h
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  AR      init/built-in.a
  LD      vmlinux.o
  MODPOST vmlinux.o
  MODINFO modules.builtin.modinfo
  KSYM    .tmp_kallsyms1.o
  KSYM    .tmp_kallsyms2.o
  LD      vmlinux
  SORTEX  vmlinux
  SYSMAP  System.map
  Building modules, stage 2.
  ITS     arch/mips/boot/vmlinux.gz.its
  OBJCOPY arch/mips/boot/vmlinux.bin
  MODPOST 7 modules
  GZIP    arch/mips/boot/vmlinux.bin.gz
  ITB     arch/mips/boot/vmlinux.gz.itb

The issue is generated by the fact that "if_changed" is called twice
in a single target.

Fix the build bug merging the two commands into a single function.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
2019-07-26 16:43:38 -07:00

216 lines
6.3 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# Objects to go into the VDSO.
# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
# the inclusion of generic Makefile.
ARCH_REL_TYPE_ABS := R_MIPS_JUMP_SLOT|R_MIPS_GLOB_DAT
include $(srctree)/lib/vdso/Makefile
obj-vdso-y := elf.o vgettimeofday.o sigreturn.o
# Common compiler flags between ABIs.
ccflags-vdso := \
$(filter -I%,$(KBUILD_CFLAGS)) \
$(filter -E%,$(KBUILD_CFLAGS)) \
$(filter -mmicromips,$(KBUILD_CFLAGS)) \
$(filter -march=%,$(KBUILD_CFLAGS)) \
$(filter -m%-float,$(KBUILD_CFLAGS)) \
-D__VDSO__
ifdef CONFIG_CC_IS_CLANG
ccflags-vdso += $(filter --target=%,$(KBUILD_CFLAGS))
endif
#
# The -fno-jump-tables flag only prevents the compiler from generating
# jump tables but does not prevent the compiler from emitting absolute
# offsets.
cflags-vdso := $(ccflags-vdso) \
$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
-O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
$(call cc-option, -fno-asynchronous-unwind-tables) \
$(call cc-option, -fno-stack-protector)
aflags-vdso := $(ccflags-vdso) \
-D__ASSEMBLY__ -Wa,-gdwarf-2
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o = -include $(c-gettimeofday-y)
# config-n32-o32-env.c prepares the environment to build a 32bit vDSO
# library on a 64bit kernel.
# Note: Needs to be included before than the generic library.
CFLAGS_vgettimeofday-o32.o = -include $(srctree)/$(src)/config-n32-o32-env.c -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday-n32.o = -include $(srctree)/$(src)/config-n32-o32-env.c -include $(c-gettimeofday-y)
endif
CFLAGS_REMOVE_vgettimeofday.o = -pg
#
# For the pre-R6 code in arch/mips/vdso/vdso.h for locating
# the base address of VDSO, the linker will emit a R_MIPS_PC32
# relocation in binutils > 2.25 but it will fail with older versions
# because that relocation is not supported for that symbol. As a result
# of which we are forced to disable the VDSO symbols when building
# with < 2.25 binutils on pre-R6 kernels. For more references on why we
# can't use other methods to get the base address of VDSO please refer to
# the comments on that file.
#
ifndef CONFIG_CPU_MIPSR6
ifeq ($(call ld-ifversion, -lt, 225000000, y),y)
$(warning MIPS VDSO requires binutils >= 2.25)
obj-vdso-y := $(filter-out gettimeofday.o, $(obj-vdso-y))
ccflags-vdso += -DDISABLE_MIPS_VDSO
endif
endif
# VDSO linker flags.
VDSO_LDFLAGS := \
-Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 \
$(addprefix -Wl$(comma),$(filter -E%,$(KBUILD_CFLAGS))) \
-nostdlib -shared -Wl,--hash-style=sysv -Wl,--build-id
CFLAGS_REMOVE_vdso.o = -pg
GCOV_PROFILE := n
UBSAN_SANITIZE := n
#
# Shared build commands.
#
quiet_cmd_vdsold_and_vdso_check = LD $@
cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check)
quiet_cmd_vdsold = VDSO $@
cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \
-Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
quiet_cmd_vdsoas_o_S = AS $@
cmd_vdsoas_o_S = $(CC) $(a_flags) -c -o $@ $<
# Strip rule for the raw .so files
$(obj)/%.so.raw: OBJCOPYFLAGS := -S
$(obj)/%.so.raw: $(obj)/%.so.dbg.raw FORCE
$(call if_changed,objcopy)
hostprogs-y := genvdso
quiet_cmd_genvdso = GENVDSO $@
define cmd_genvdso
$(foreach file,$(filter %.raw,$^),cp $(file) $(file:%.raw=%) &&) \
$(obj)/genvdso $(<:%.raw=%) $(<:%.dbg.raw=%) $@ $(VDSO_NAME)
endef
#
# Build native VDSO.
#
native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS))
targets += $(obj-vdso-y)
targets += vdso.lds
targets += vdso.so.dbg.raw vdso.so.raw
targets += vdso.so.dbg vdso.so
targets += vdso-image.c
obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o)
$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi)
$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi)
$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi)
$(obj)/vdso.so.dbg.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold_and_vdso_check)
$(obj)/vdso-image.c: $(obj)/vdso.so.dbg.raw $(obj)/vdso.so.raw \
$(obj)/genvdso FORCE
$(call if_changed,genvdso)
obj-y += vdso-image.o
#
# Build O32 VDSO.
#
# Define these outside the ifdef to ensure they are picked up by clean.
targets += $(obj-vdso-y:%.o=%-o32.o)
targets += vdso-o32.lds
targets += vdso-o32.so.dbg.raw vdso-o32.so.raw
targets += vdso-o32.so.dbg vdso-o32.so
targets += vdso-o32-image.c
ifdef CONFIG_MIPS32_O32
obj-vdso-o32 := $(obj-vdso-y:%.o=$(obj)/%-o32.o)
$(obj-vdso-o32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=32
$(obj-vdso-o32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=32
$(obj)/%-o32.o: $(src)/%.S FORCE
$(call if_changed_dep,vdsoas_o_S)
$(obj)/%-o32.o: $(src)/%.c FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
$(obj)/vdso-o32.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) -mabi=32
$(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE
$(call if_changed_dep,cpp_lds_S)
$(obj)/vdso-o32.so.dbg.raw: $(obj)/vdso-o32.lds $(obj-vdso-o32) FORCE
$(call if_changed,vdsold_and_vdso_check)
$(obj)/vdso-o32-image.c: VDSO_NAME := o32
$(obj)/vdso-o32-image.c: $(obj)/vdso-o32.so.dbg.raw $(obj)/vdso-o32.so.raw \
$(obj)/genvdso FORCE
$(call if_changed,genvdso)
obj-y += vdso-o32-image.o
endif
#
# Build N32 VDSO.
#
targets += $(obj-vdso-y:%.o=%-n32.o)
targets += vdso-n32.lds
targets += vdso-n32.so.dbg.raw vdso-n32.so.raw
targets += vdso-n32.so.dbg vdso-n32.so
targets += vdso-n32-image.c
ifdef CONFIG_MIPS32_N32
obj-vdso-n32 := $(obj-vdso-y:%.o=$(obj)/%-n32.o)
$(obj-vdso-n32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=n32
$(obj-vdso-n32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=n32
$(obj)/%-n32.o: $(src)/%.S FORCE
$(call if_changed_dep,vdsoas_o_S)
$(obj)/%-n32.o: $(src)/%.c FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
$(obj)/vdso-n32.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) -mabi=n32
$(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE
$(call if_changed_dep,cpp_lds_S)
$(obj)/vdso-n32.so.dbg.raw: $(obj)/vdso-n32.lds $(obj-vdso-n32) FORCE
$(call if_changed,vdsold_and_vdso_check)
$(obj)/vdso-n32-image.c: VDSO_NAME := n32
$(obj)/vdso-n32-image.c: $(obj)/vdso-n32.so.dbg.raw $(obj)/vdso-n32.so.raw \
$(obj)/genvdso FORCE
$(call if_changed,genvdso)
obj-y += vdso-n32-image.o
endif
# FIXME: Need install rule for debug.
# Needs to deal with dependency for generation of dbg by cmd_genvdso...