Re: same prog, different sizes

Jorge Almeida and Steven Honeyman wrote:

Steven>>> On your Gentoo i3... am I right in thinking you have a hardened/PaX
Steven>>> build environment?

Jorge>> Nope. It's a standard profile, no fancy
Jorge>> stuff whatsoever (box is used to backups and compiling some stuff,
Jorge>> used mainly via ssh, not even X installed)

Steven> Oh well, worth a guess! I just noticed this strange program header
Steven> entry (only in the i3 version), which google says has something to do
Steven> with PaX. They are both the same binary really, but the i3 has a few
Steven> kb of padding on the end (just empty space). I have no idea why; but
Steven> I'm sure someone will be able to help you.

I think Steven's right.  For instance, see:

   https://blogs.gentoo.org/mgorny/2014/06/23/inlining-marchnative-for-distcc/

which says (about flags being bandied about by `gcc`):

" You may also notice -fstack-protector there. This is because nowadays
" Gentoo enables it by default.

-- the 2nd sentence links to:

   http://sources.gentoo.org/gitweb/?p=proj/gentoo-news.git;a=blob;f=2014/2014-06-15-gcc48_ssp/2014-06-15-gcc48_ssp.en.txt

which certainly seems to support the claim.

The two binaries contain .comment sections with "GCC: (GNU) 4.8.2" and
"GCC: (Gentoo 4.8.3 p1.1, pie-0.5.9) 4.8.3"; in which I *think* the
"pie-0.5.9" is another hint about hardening.

>Bela<