NX emulation

[Roland McGrath]

> Doesn't appear to work? 
> 
> kyle at dreadnought ~/src/linux-2.6 $ git remote
> add kees-execshield git://kernel.ubuntu.com/kees/linux-2.6.git
> kyle at dreadnought ~/src/linux-2.6 $ git fetch kees-execshield
> kernel.ubuntu.com[0: 91.189.94.216]: errno=Connection timed out
> fatal: unable to connect a socket (Connection timed out)

It worked for me.  
That seems to be a large uncoordinated branch of many topics.
I guessed just from the log summary which commits are these ones:

	git log -n3 6bf4df3

(I haven't really reviewed the changes.)

Kees, if you are looking for review, putting these on an isolated topic
branch for people to look at easily is probably a good idea.

> Yes, we've been saying for a while that the randomization stuff needs to
> be gutted from exec-shield. There is still a lot of work left cleaning
> up exec-shield, all the hooks are pretty out of order.

It was vaguely on my list for ages to clean up execshield and slice it into
separate patches, but I just gave up on ever getting around to it.  One
should probably ping Ingo, since (AFAIK) he did it all to begin with, back
in the beforetime, the long, long ago.

The exec-shield boot/sysctl parameter has never made a whole lot of sense
to me.  The "exec-shield" stuff is really about three separate things.  If
they need knobs, it's always seemed to me they should have separate knobs.

> I suspect all this is still too invasive in the generic code to be
> palatable. 

I haven't really looked at Kees' patches.  But having considered before
factoring this stuff out to cleanish, the i386 "NX emulation" stuff seemed
like the first thing to do and not hard to do fairly cleanly.  (Not that
this motivated me to bother doing it.)


Thanks,
Roland