[CentOS] Information about ASLR (Address Space Layout Randomization) in CentOS 5

Fri Dec 12 14:59:01 UTC 2008
Filipe Brandenburger <filbranden at gmail.com>


We are porting some applications from CentOS 4 to CentOS 5, the
applications use mmap, and we found out that they sometimes crash in
CentOS 5. We found out that this is due to the fact that CentOS 5 does
randomization of the address space when loading binaries, libraries,
and when using mmap, so that is what's causing our problem.

The thing is, I'm trying to google for it, but I did not find any
useful information on ASLR present in CentOS 5/RHEL 5/Linux 2.6.18. If
anyone has any good pointers on reliable information on what does that
code do, how to configure/tweak it, or how to use mmap properly to
work around the issues, I would really appreciate it. In particular,
if there is a switch/option that would allow us to disable it for some
binaries/libraries only, it would be great, since this could allow us
to do the upgrade sooner and try to find the proper fix for the
problem later.