probe.kernel.sys_open.entry()
{
  $dynamic_call_graph =1;
}

# What you would see in the output would be something of this kind
# call sys_open
#     call getname
#          call do_getname
#           return do_getname
#     return getname
#     call get_unused_fd
#         call find_next_zero_bit
#         return find_next_zero_bit
#     return get_unused_fd
#     call filep_open
      .....
return sys_open

# The above probe could be customized to a particular process as well,
# like in the following

probe.kernel.sys_open.entry()
{
if ($PID == 1234)
    $dynamic_call_graph =1;
}