gdb ./vmlinux GNU gdb (GDB) 7.3.50.20110521-cvs (gdb) p 123*4 GDB does not (yet) know how to evaluate that kind of expression /usr/bin/gdb ./vmlinux GNU gdb (GDB) 7.2-ubuntu (gdb) p 123*4 $1 = 492 What is happen? Thanks, Hui