Re: [PATCH] x86: ptrace debugreg checks rewrite

[Ingo Molnar <mingo@elte.hu>]

* Roland McGrath <roland@redhat.com> wrote:

> > > On Mon, May 04, 2009 at 04:16:01AM +0400, Alexey Dobriyan wrote:
> > > > +static int ptrace_check_debugreg(int _32bit,
> > > > +				 unsigned long dr0, unsigned long dr1,
> > > > +				 unsigned long dr2, unsigned long dr3,
> > > > +				 unsigned long dr6, unsigned long dr7)
> > > > +{
> > > > +	/* Breakpoint type: 00: --x, 01: -w-, 10: undefined, 11: rw- */
> > > > +	unsigned int rw[4];
> > > > +	/* Breakpoint length: 00: 1 byte, 01: 2 bytes, 10: 8 bytes, 11: bytes */
> > > 								        4 bytes, of course
> > 
> > Roland, Oleg, do you have any pending/planned changes in this area?
> 
> I don't.  I expect the only future work on this arch debugreg 
> stuff to be via the hw_breakpoint work, extending that and/or 
> building new things on it.

Yes. That work, despite being in its upteenth iteration, is taking a 
frustratingly long amount of time to get even to a minimal "review 
passed, lets commit and test this in a tree a bit" intermediate 
stage though.

I've Cc:-ed K.Prasad and Alan Stern. Roland, Oleg, would you be 
interested in having a look at that thread, to help drive it 
forward?

The last iteration was posted to lkml on Apr 24:

  [Patch 00/12] Hardware Breakpoint Interfaces

and it has a good deal of ptrace, signal handling and other impact 
as well.

	Ingo