As Ingo mentioned above, Systemtap uses kprobes infrastructure to provide
dynamic kernel instrumentation. Using which user can add lots of probes easily, so we foreed to take care of this fast path.
Instead of calling convert_eip_to_linear() for all cases, you can
just check if it is in kernel mode and calculate the address directly
if (kernel mode)
addr = regs->eip - sizeof(kprobe_opcode_t);
else
addr = convert_eip_to_linear(..);
there by avoiding call to convert_eip_to_linear () for every kernel probes.
As Andi mentioned user space probes support is in progress and this address conversion will help in case of user space probes as well.