mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 22:21:59 +07:00
ebb5e78cc6
Add an initial implementation of a proper (i.e. an ELF shared library) VDSO. With this commit it does not export any symbols, it only replaces the current signal return trampoline page. A later commit will add user implementations of gettimeofday()/clock_gettime(). To support both new toolchains and old ones which don't generate ABI flags section, we define its content manually and then use a tool (genvdso) to patch up the section to have the correct name and type. genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the kernel, and generates a C file containing a "struct mips_vdso_image" containing both the VDSO data and these offsets. This C file is compiled into the kernel. On 64-bit kernels we require a different VDSO for each supported ABI, so we may build up to 3 different VDSOs. The VDSO to use is selected by the mips_abi structure. A kernel/user shared data page is created and mapped below the VDSO image. This is currently empty, but will be used by the user time function implementations which are added later. [markos.chandras@imgtec.com: - Add more comments - Move abi detection in genvdso.h since it's the get_symbol function that needs it. - Add an R6 specific way to calculate the base address of VDSO in order to avoid the branch instruction which affects performance. - Do not patch .gnu.attributes since it's not needed for dynamic linking. - Simplify Makefile a little bit. - checkpatch fixes - Restrict VDSO support for binutils < 2.25 for pre-R6 - Include atomic64.h for O32 variant on MIPS64] Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11337/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
161 lines
4.3 KiB
Makefile
161 lines
4.3 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, -gt, 22400000, y),)
|
|
$(warning MIPS VDSO requires binutils > 2.24)
|
|
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 $@
|
|
|
|
hostprogs-y := genvdso
|
|
|
|
quiet_cmd_genvdso = GENVDSO $@
|
|
define cmd_genvdso
|
|
cp $< $(<:%.dbg=%) && \
|
|
$(OBJCOPY) -S $< $(<:%.dbg=%) && \
|
|
$(obj)/genvdso $< $(<:%.dbg=%) $@ $(VDSO_NAME)
|
|
endef
|
|
|
|
#
|
|
# Build native VDSO.
|
|
#
|
|
|
|
native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS))
|
|
|
|
targets += $(obj-vdso-y)
|
|
targets += vdso.lds vdso.so.dbg vdso.so 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: $(obj)/vdso.lds $(obj-vdso) FORCE
|
|
$(call if_changed,vdsold)
|
|
|
|
$(obj)/vdso-image.c: $(obj)/vdso.so.dbg $(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 vdso-o32.so.dbg vdso-o32.so 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: $(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 $(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 vdso-n32.so.dbg vdso-n32.so 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: $(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 $(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...
|