[PATCH] Force read implies exec for all 32bit processes in x86-64

[PATCH] Force read implies exec for all 32bit processes in x86-64

This effectively enables executable stack and executable heap for all 32bit
programs on x86-64, except if noexec32=on is specified.

This does not support changing this with personality right now, this would
need more intrusive changes.  A 64bit process will always turn it off and a
32bit process turn it on.

Also readd the noexec32=on option to turn this off and fix a minor bug in
noexec=...  (would be reported as unknown option)

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>