Re: [build fail] v6.11-rc2 from "ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION"

[liuyuntao (F)]

OK, i will test these version soon.

On 2024/8/7 23:41, Arnd Bergmann wrote:
> On Wed, Aug 7, 2024, at 17:36, Harith George wrote:
> > On 07-08-2024 20:52, liuyuntao (F) wrote:
> > > Thanks, I reproduce the link error with toolchain
> > > gcc version 9.3.0
> > > GNU ld (GNU Binutils) 2.33.1
> > >
> > > with same gcc version, just upgrading ld version to 2.36.1, it does not
> > > segfault and build completes. there should be bugs in low version of ld,
> > > and the ".reloc  .text, R_ARM_NONE, ." triggers that.
> > Thanks for confirming.
> >
> > I guess we need to add something like
> > #if !CONFIG_CC_IS_GCC || CONFIG_LD_VERSION >= 23600
> > around the entry-armv.S changes and maybe select
> > HAVE_LD_DEAD_CODE_DATA_ELIMINATION in arch/arm/Kconfig only if the same
> > conditions are met ??
>
> I think it makes most sense to have a minimum LD
> version as a dependency for HAVE_LD_DEAD_CODE_DATA_ELIMINATION.
> Are you sure that 2.36 is the first one that works, and it's
> not just 2.33 specifically that is broken?
>
> If so, we could use
>
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -117,7 +117,7 @@ config ARM
>          select HAVE_KERNEL_XZ
>          select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M && !CPU_32v3
>          select HAVE_KRETPROBES if HAVE_KPROBES
> -       select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
> +       select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD)
>          select HAVE_MOD_ARCH_SPECIFIC
>          select HAVE_NMI
>          select HAVE_OPTPROBES if !THUMB2_KERNEL
>
>
> binutils only takes a few seconds to build from source, so
> you could just try all version from 2.25 (the oldest supported)
> to 2.36) to see which ones work.
>
>         Arnd