You can use the Gnu Debugger (gdb) which I believe comes with the bin-utils.
There is a great book on Assemble Language programming in Linux called Professional Assembly Language by Richard Blum (Wrox). He has a section in there about using the gdb for debugging. He also claims you can use Kdb but I have not had as much luck (nor have I spent as much time). It looks like it would be nice if it worked.