/** @dir branch_dest
This is a silly little instrumentation routine to instrument a branch
or call by address. It makes use of the SystemTap runtime libraries to break
down the number of times the function by caller. 

It demonstrates kprobes, passing a module parameter, using the print buffer,
and using _stp_print_symbol() to map the addresses back to locations 
in functions.

There is no default branch_address that it instruments. The
branch_address paramter must be specified when the module is loaded.

The instrumentation module is built by having the kernel that is going
to be instrumented currently on the machine and doing 
\code
./build
\endcode
The instrumentation is inserted as root with:
\code
/sbin/insmod kprobe_branch_dest.ko branch_address=0xNNNNNNN
\endcode
The instrumentation is removed as root with:
\code
/sbin/rmmod kprobe_branh_dest
\endcode
-Will Cohen
*/
