Hi, 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. Thanks! Filipe