[PATCH] Add Prefer_MAP_32BIT_EXEC for Silvermont

[Carlos O'Donell]

On 12/15/2015 01:27 PM, Carlos O'Donell wrote:
> +  cpu_features->feature[index_Prefer_MAP_32BIT_EXEC]
> +    |= get_prefer_map_32bit_exec ();
> 
> You wouldn't need get_prefer_map_32bit_exec, since this is all part of
> the code, like dl-librecon.h, which parses the extra env var.

To be clear:

* Add new bit flag definitions for cpu_features.
* Add a sysdeps/unix/sysv/linux/x86_64/dl-silvermont.h
  * Fill in EXTRA_LD_ENVVARS or add new ones.
  * Write to rtld's GLRO cpu_features the bit you need based
    on __libc_enable_secure.

That should simplify and concentrate the Silvermont fixes to
just two files, making future maintenance and documentation
easier.

$0.02.

Cheers,
Carlos.