how to determine whether the source code is same between two kernels

[wuzhouhui]

Hi,

Suppose I have two kernels, one is A.B.C build by people Tom. And
the other is A.B.C build by Jerry. The source code have been deleted
after kernel is build and installed. Now I want to know whether the
source code of these two kernel is the same (even if they have the same
name). All I have is binaries (e.g. vmlinux, config, *.ko, System.map).
Is it possible?

Thanks