Andi Kleen wrote: > On Wednesday 23 August 2006 11:01, Zachary Amsden wrote: > >> Andi Kleen wrote: >> >>>> Yes, after discussion with Rusty, it appears that beefing up >>>> stop_machine_run is the right way to go. And it has benefits for >>>> non-paravirt code as well, such as allowing plug-in kprobes or oprofile >>>> extension modules to be loaded without having to deal with a debug >>>> exception or NMI during module load/unload. >>>> >>>> >>> I'm still unclear where you think those debug exceptions will come from >>> >> kprobes set in the stop_machine code - which is probably a really bad >> idea, but nothing today actively stops kprobes from doing that. >> > > kprobes don't cause any debug exceptions. You mean int3? > > Anyways this can be fixed by marking the stop machine code __kprobes > > -Andi > I need to look at the kprobes code in more depth to answer completely. But in general, there could be a problem if DRs are set to fire on any EIP or memory address touched during the critical stop_machine region, or int3 breakpoints are set in that code or any code it calls. Zach
