kprobe fault handling

[Martin Hunt]

On Tue, 2006-02-07 at 12:35 -0800, Keshavamurthy, Anil S wrote:
> >I just had a long chat with Richard Moore about this whole topic.  I
> >agree with you on this, and I think Richard would, too.
> >
> >So unless there's a user-specified handler and that handler specifies
> >(by returning 1) that it has handled the exception,
> >kprobe_fault_handler() should run fixup_exception(), right?
> >
> >Now I'm looking, later in that function, at the code (on i386) where we
> >handle an exception while single-stepping.  I don't think
> >resume_execution() is the right thing to do here.  We haven't
> >successfully executed the probed instruction, and the eip still points
> >at that instruction, right?  I think we're just hosed at this point. 
> >Comments?
> I agree with your comments and we need a better fix. 
> Currently for RHEL4 release I am inclined to remove 
> DIE_PAGE_FAULT switch case as this at least improves 
> the performance.

Anil. Did you read this thread, starting at
http://sources.redhat.com/ml/systemtap/2006-q1/msg00392.html

How will removing page fault handling fix our broken page fault
handling?

Martin