[AD] More "mprotect" troubles (4.2.1 showstopper?)

[Hans de Goede <j.w.r.degoede@xxxxxxxxxx>]

Hi,

See:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=185214

I'm working on a nice clean fix for this involving a temp file and mmap 
as described in the above url.

Also notice that even without selinux the current mprotect patch is 
incomplete, it doesn't make the code generated in src/i386/icsprite.c 
executable.

I think I have a fix wednesday at the latest, is that in time for 4.2.1?

I'll make the fix conditonal on unix, or maybe even linux it will require:
mmap
mkstemp

My idea is the following:

Use a grow_buffer and a buffer macro (I wil come up with better names) 
in opcodes.h and use these instead of _grow_scratch_mem and 
_scratch_mem.  grow_buffer and buffer will normally be defined to 
_grow_scratch_mem and _scratch_mem leaving things unchanged, but they 
will use mmap and mremap (for growing) on a tempfile when needed.

Regards,

Hans