Re: [PATCH] powerpc: clean up binutils version check

[Christophe Leroy]

Le 27/08/2022 à 20:03, Masahiro Yamada a écrit :
> On Sun, Aug 28, 2022 at 2:37 AM Christophe Leroy
> <christophe.leroy@xxxxxxxxxx> wrote:
>>
>>
>>
>> Le 27/08/2022 à 18:40, Masahiro Yamada a écrit :
>>> The checkbin in arch/powerpc/Makefile errors out if ld <= 2.24.
>>> So, the requirement on PPC is binutils >= 2.25. It is cleaner to
>>> specify it in scripts/min-tool-version.sh. If binutils < 2.25 is
>>> used, the toolchain check will fail in the Kconfig stage going
>>> forward.
>>>
>>> Since binutils >= 2.25 is already required, another version test
>>> for --save-restore-funcs on PPC64 is always met.
>>>
>>> PPC is the last user of ld-ifversion. With all the callers removed,
>>> the macro definition in scripts/Makefile.compiler can go away.
>>>
>>> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
>>> ---
>>>
>>>    arch/powerpc/Makefile       | 21 ---------------------
>>>    arch/powerpc/lib/Makefile   |  8 --------
>>>    scripts/Makefile.compiler   |  4 ----
>>>    scripts/min-tool-version.sh |  8 +++++++-
>>>    4 files changed, 7 insertions(+), 34 deletions(-)
>>>
>>> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
>>> index 02742facf895..fb607758eeca 100644
>>> --- a/arch/powerpc/Makefile
>>> +++ b/arch/powerpc/Makefile
>>> @@ -46,13 +46,7 @@ UTS_MACHINE := $(subst $(space),,$(machine-y))
>>>    ifdef CONFIG_PPC32
>>>    KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
>>>    else
>>> -ifeq ($(call ld-ifversion, -ge, 22500, y),y)
>>> -# Have the linker provide sfpr if possible.
>>> -# There is a corresponding test in arch/powerpc/lib/Makefile
>>>    KBUILD_LDFLAGS_MODULE += --save-restore-funcs
>>> -else
>>> -KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
>>> -endif
>>>    endif
>>>
>>>    ifdef CONFIG_CPU_LITTLE_ENDIAN
>>> @@ -395,8 +389,6 @@ vdso_prepare: prepare0
>>>                $(build)=arch/powerpc/kernel/vdso include/generated/vdso64-offsets.h)
>>>    endif
>>>
>>> -archprepare: checkbin
>>> -
>>>    archheaders:
>>>        $(Q)$(MAKE) $(build)=arch/powerpc/kernel/syscalls all
>>>
>>> @@ -411,16 +403,3 @@ else
>>>        $(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h))
>>>    endif
>>>    endif
>>> -
>>> -PHONY += checkbin
>>> -# Check toolchain versions:
>>> -# - gcc-4.6 is the minimum kernel-wide version so nothing required.
>>> -checkbin:
>>> -     @if test "x${CONFIG_LD_IS_LLD}" != "xy" -a \
>>> -             "x$(call ld-ifversion, -le, 22400, y)" = "xy" ; then \
>>> -             echo -n '*** binutils 2.24 miscompiles weak symbols ' ; \
>>> -             echo 'in some circumstances.' ; \
>>> -             echo    '*** binutils 2.23 do not define the TOC symbol ' ; \
>>> -             echo -n '*** Please use a different binutils version.' ; \
>>> -             false ; \
>>> -     fi
>>> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
>>> index 8560c912186d..5eb3971ccb9c 100644
>>> --- a/arch/powerpc/lib/Makefile
>>> +++ b/arch/powerpc/lib/Makefile
>>> @@ -38,14 +38,6 @@ obj-$(CONFIG_PPC32)        += div64.o copy_32.o crtsavres.o
>>>
>>>    obj-$(CONFIG_FUNCTION_ERROR_INJECTION)      += error-inject.o
>>>
>>> -# See corresponding test in arch/powerpc/Makefile
>>> -# 64-bit linker creates .sfpr on demand for final link (vmlinux),
>>> -# so it is only needed for modules, and only for older linkers which
>>> -# do not support --save-restore-funcs
>>> -ifeq ($(call ld-ifversion, -lt, 22500, y),y)
>>> -extra-$(CONFIG_PPC64)        += crtsavres.o
>>> -endif
>>> -
>>>    obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
>>>                               memcpy_power7.o restart_table.o
>>>
>>> diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
>>> index 94d0d40cddb3..63e7d79dd877 100644
>>> --- a/scripts/Makefile.compiler
>>> +++ b/scripts/Makefile.compiler
>>> @@ -68,7 +68,3 @@ cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || e
>>>    # ld-option
>>>    # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
>>>    ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
>>> -
>>> -# ld-ifversion
>>> -# Usage:  $(call ld-ifversion, -ge, 22252, y)
>>> -ld-ifversion = $(shell [ $(CONFIG_LD_VERSION)0 $(1) $(2)0 ] && echo $(3) || echo $(4))
>>> diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
>>> index 250925aab101..7df9f2150ea1 100755
>>> --- a/scripts/min-tool-version.sh
>>> +++ b/scripts/min-tool-version.sh
>>> @@ -14,7 +14,13 @@ fi
>>>
>>>    case "$1" in
>>>    binutils)
>>> -     echo 2.23.0
>>> +     if [ "$SRCARCH" = powerpc ]; then
>>
>> Isn't this limitation only for ppc64le ?
>>
>> Refer commit 60e065f70bdb ("powerpc: Reject binutils 2.24 when building
>> little endian")
> 
> 
> I do not see any CONFIG check in the current checkbin.
> 
> Refer commit a3ad84da0760 ("powerpc/toc: Future proof
> kernel toc")
> 

That's odd. There is no toc on PPC32.

Christophe