linux/arch/mips/vdso/Makefile
James Hogan 2afb974543 MIPS: Fix genvdso error on rebuild
The genvdso program modifies the debug and stripped versions of the
VDSOs in place, and errors if the modification has already taken place.
Unfortunately this means that a rebuild which tries to rerun genvdso to
generate vdso*-image.c without also rebuilding vdso.so.dbg (for example
if genvdso.c is modified) hits a build error like this:

arch/mips/vdso/genvdso 'arch/mips/vdso/vdso.so.dbg' already contains a '.MIPS.abiflags' section

This is fixed by reorganising the rules such that unmodified .so files
have a .raw suffix, and these are copied in the same rule that runs
genvdso on the copies.

I.e. previously we had:

 cmd_vdsold:
  link objects -> vdso.so.dbg

 cmd_genvdso:
  strip vdso.so.dbg -> vdso.so
  run genvdso -> vdso-image.c
   and modify vdso.so.dbg and vdso.so in place

Now we have:

 cmd_vdsold:
  link objects -> vdso.so.dbg.raw

 a new cmd_objcopy based strip rule (inspired by ARM):
  strip vdso.so.dbg.raw -> vdso.so.raw

 cmd_genvdso:
  copy vdso.so.dbg.raw -> vdso.so.dbg
  copy vdso.so.raw -> vdso.so
  run genvdso -> vdso-image.c
   and modify vdso.so.dbg and vdso.so in place

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13250/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 22:47:39 +02:00

177 lines
4.9 KiB
Makefile

# Objects to go into the VDSO.
obj-vdso-y := elf.o gettimeofday.o sigreturn.o
# Common compiler flags between ABIs.
ccflags-vdso := \
$(filter -I%,$(KBUILD_CFLAGS)) \
$(filter -E%,$(KBUILD_CFLAGS)) \
$(filter -march=%,$(KBUILD_CFLAGS))
cflags-vdso := $(ccflags-vdso) \
$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
-O2 -g -fPIC -fno-common -fno-builtin -G 0 -DDISABLE_BRANCH_PROFILING \
$(call cc-option, -fno-stack-protector)
aflags-vdso := $(ccflags-vdso) \
$(filter -I%,$(KBUILD_CFLAGS)) \
$(filter -E%,$(KBUILD_CFLAGS)) \
-D__ASSEMBLY__ -Wa,-gdwarf-2
#
# 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 \
-nostdlib -shared \
$(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
$(call cc-ldoption, -Wl$(comma)--build-id)
GCOV_PROFILE := n
#
# Shared build commands.
#
quiet_cmd_vdsold = VDSO $@
cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \
-Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -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 := $(native-abi)
$(obj)/vdso.so.dbg.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
$(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,as_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 := -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)
$(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,as_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 := -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)
$(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...