The Extensible Firmware Interface - an introduction

Debian's kexec-tools package for instance always boots /vmlinuz, which is a symlink maintained by the various linux-image-* packages and which usually points to the latest installed kernel. IMO this is a mistake, and kexec should attempt to boot into the currently installed kernel, if it still exists.

This doesn't sound too hard--just look at the results of uname(2) and then look for a matching file in /boot. I think this would make your scenario less likely, however (at least in Debian's case) they only use a different filename for different kernel releases and ABI-changing updates to the same release, so the file /boot/vmlinux-3.0.0-1-amd64 that currently exists on my system may have been updated since the system booted with a file of the same name.