Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220830190811.323760-1-masahiroy@kernel.org> <20220830190811.323760-2-masahiroy@kernel.org>
In-Reply-To: <20220830190811.323760-2-masahiroy@kernel.org>
From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Tue, 30 Aug 2022 14:13:20 -0700
Message-ID: <CAKwvOd=4F-_5+txzbNy4sC8tADGmiEtbVL64CCiAp7nmgyUTnQ@mail.gmail.com>
Subject: Re: [PATCH 2/2] powerpc: remove old code for binutils < 2.25
To:     Masahiro Yamada <masahiroy@kernel.org>
Cc:     Michael Ellerman <mpe@ellerman.id.au>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Aug 30, 2022 at 12:10 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> The minimum supported version of binutils has been raised to 2.25.1.
> Drop the old code.
>
> 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@kernel.org>
> ---
>
>  arch/powerpc/Makefile     | 21 ---------------------
>  arch/powerpc/lib/Makefile |  8 --------
>  scripts/Makefile.compiler |  4 ----
>  3 files changed, 33 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.

^ Perhaps this comment is still relevant and should not yet be
discarded? Or updated, dropping " if possible".

Either way:
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> -# 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))
> --
> 2.34.1
>


-- 
Thanks,
~Nick Desaulniers