[PATCH 1/2] powerpc/vmlinux.lds: Explicitly retain .gnu.hash

[Alan Modra]

On Thu, Feb 27, 2020 at 03:59:32PM +1100, Michael Ellerman wrote:
> Relocatable kernel builds produce a warning about .gnu.hash being an
> orphan section:
> 
>   ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'
> 
> If we try to discard it the build fails:
> 
>   ld -EL -m elf64lppc -pie --orphan-handling=warn --build-id -o
>     .tmp_vmlinux1 -T ./arch/powerpc/kernel/vmlinux.lds --whole-archive
>     arch/powerpc/kernel/head_64.o arch/powerpc/kernel/entry_64.o
>     ...
>     sound/built-in.a net/built-in.a virt/built-in.a --no-whole-archive
>     --start-group lib/lib.a --end-group
>   ld: could not find section .gnu.hash
> 
> So add an entry to explicitly retain it, as we do for .hash.

Looks fine to me.  You can also pass --hash-style=sysv to ld (since
binutils-2.18) to disable generation of .gnu.hash.

> 
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
> ---
>  arch/powerpc/kernel/vmlinux.lds.S | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
> index b4c89a1acebb..31a0f201fb6f 100644
> --- a/arch/powerpc/kernel/vmlinux.lds.S
> +++ b/arch/powerpc/kernel/vmlinux.lds.S
> @@ -256,6 +256,7 @@ SECTIONS
>  		*(.dynamic)
>  	}
>  	.hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) }
> +	.gnu.hash : AT(ADDR(.gnu.hash) - LOAD_OFFSET) { *(.gnu.hash) }
>  	.interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) }
>  	.rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET)
>  	{
> -- 
> 2.21.1

-- 
Alan Modra
Australia Development Lab, IBM