Re: [PATCH] x86-64: fix vDSO build

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 03 Jul 2014 15:34:38 +0100 "Jan Beulich" <JBeulich@suse.com> wrote:

> Certain ld versions (observed with 2.20.0) put an empty .rela.dyn
> section into shared object files, breaking the assumption on the number
> of sections to be copied to the final output. Simply discard any empty
> SHT_REL and SHT_RELA sections to address this.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> ---
>  arch/x86/vdso/vdso2c.h |    3 +++
>  1 file changed, 3 insertions(+)
> 
> --- 3.16-rc3/arch/x86/vdso/vdso2c.h
> +++ 3.16-rc3-x86-vdso-build/arch/x86/vdso/vdso2c.h
> @@ -93,6 +93,9 @@ static void BITSFUNC(copy_section)(struc
>  	uint64_t flags = GET_LE(&in->sh_flags);
>  
>  	bool copy = flags & SHF_ALLOC &&
> +		(GET_LE(&in->sh_size) ||
> +		 (GET_LE(&in->sh_type) != SHT_RELA &&
> +		  GET_LE(&in->sh_type) != SHT_REL)) &&
>  		strcmp(name, ".altinstructions") &&
>  		strcmp(name, ".altinstr_replacement");

Tested-by: Andrew Morton <akpm@linux-foundation.org>

(hint)