[PATCH] Add Prefer_MAP_32BIT_EXEC for Silvermont

[H.J. Lu]

On Tue, Dec 15, 2015 at 10:38 AM, Carlos O'Donell <carlos@redhat.com> wrote:
> 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.
>
>

This is the updated patch.  I put EXTRA_LD_ENVVARS and
EXTRA_UNSECURE_ENVVARS in x86_64/64/dl-librecon.h
to be consistent with i386/dl-librecon.h.  If we ever need to
update EXTRA_LD_ENVVARS/EXTRA_UNSECURE_ENVVARS
in the future, we have a single file to change.

Tested on x86-64.  OK for master?

Thanks for all the feedbacks and suggestions.

-- 
H.J.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Add-Prefer_MAP_32BIT_EXEC-to-map-executable-pages-wi.patch
Type: text/x-patch
Size: 8295 bytes
Desc: not available
URL: <http://sourceware.org/pipermail/libc-alpha/attachments/20151215/bf9dc146/attachment.bin>