How to building a linux executable in CentOS 5 and running it on RedHat 9?

We had just migrated our software to CentOS 5 platform, from RedHat 9. We're now compiling our C programs on CentOS 5 using gcc v4.1.2 and everything works fine on CentOS, but these new binaries will not run on RedHat 9 anymore (kernel 2.4.1). Any suggestions on how we can compile a binary that can run on both of these开发者_StackOverflow中文版 platforms?

Try mock. See http://fedoraproject.org/wiki/Projects/Mock and https://fedorahosted.org/mock/ or just install CentOS' mock package and add an F9 config for it.

Caution: F9 has not been supported in years.