Re: PATCH: Handle R_X86_64_RELATIVE64 and R_X86_64_64 for x32

[Roland McGrath <roland at hack dot frob dot com>]

> +# if !defined RTLD_BOOTSTRAP && defined __ILP32__
> +  /* l_addr + r_addend may be > 0xffffffff and R_X86_64_RELATIVE64
> +     relocation updates the whole 64-bit entry.  */
> +  if (__builtin_expect (r_type == R_X86_64_RELATIVE64, 0))
> +    *(Elf64_Addr *) reloc_addr = (Elf64_Addr) map->l_addr + reloc->r_addend;
> +  else
> +# endif

There's no reason x86_64 proper shouldn't handle R_X86_64_RELATIVE64 too.
So drop the __ILP32__ condition.  Would it really be a problem for
R_X86_64_RELATIVE to be treated as a whole 64 bits for x32?  If not, then
you can just merge this into the existing case by making the test accept
either code.

> +#  ifdef __ILP32__
> +	  /* value + r_addend may be > 0xffffffff and R_X86_64_64
> +	     relocation updates the whole 64-bit entry.  */
> +	  *(Elf64_Addr *) reloc_addr = (Elf64_Addr) value + reloc->r_addend;
> +#  else
>  	  *reloc_addr = value + reloc->r_addend;
> +#  endif

Likewise here, you can drop the #ifdef and just use the version with the
casts for eitehr case.

> +#ifdef __ILP32__
> +  /* l_addr + r_addend may be > 0xffffffff and R_X86_64_RELATIVE64
> +     relocation updates the whole 64-bit entry.  */
> +  if (__builtin_expect (ELFW(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE64, 0))
> +    {
> +      *(Elf64_Addr *) reloc_addr = (Elf64_Addr) l_addr + reloc->r_addend;
> +      return;
> +    }
> +#endif
>    assert (ELFW(R_TYPE) (reloc->r_info) == R_X86_64_RELATIVE);
>    *reloc_addr = l_addr + reloc->r_addend;

Again, unless there's a real problem with the 64-bit treatment for x32,
then just make the assert accept either type.


Thanks,
Roland