Re: [ppc-linux-nat]: set access flag for h/w watchpoint even if it is only read or write

Ulrich Weigand
2006-07-08T19:36:48Z

Eli Zaretskii wrote:
> > Date: Fri, 7 Jul 2006 09:17:54 -0400
> > From: Daniel Jacobowitz <drow@false.org>
> > Cc: Wu Zhou <woodzltc@cn.ibm.com>, gdb-patches@sourceware.org
> >
> > > Daniel, could you please point me to Ulrich's change, either in
> > > ChangeLogs or in the sources? I cannot find it forf some reason.
> >
> > I must be mistaken; our S/390 support doesn't have any read watchpoints
> > (I don't know if the architecture does or not). In fact I can't find
> > any architecture that does this. But I immediately recognized
> > the description of the problem... so it must have happened somewhere.
>
> You are not dreaming, because I remember that as well. Perhaps Ulrich
> just suggested a change, but it wasn't accepted eventually.

I'm not sure which conversation you're referring to. In any case, S/390
does not support read watchpoints at all, neither by themselves nor in
combination with a write watchpoint. The only type of hardware watchpoint
it supports is the pure write watchpoint.

I do recall some discussion about watchpoints on S/390, but that had to
do with the fact that on our platform, the hardware does not identify
the data address that triggered the watchpoint, and there were some
changes to GDB common code that implicitly assumed that the target
should be able to do that ...

Bye,
Ulrich

--
Dr. Ulrich Weigand
Linux on zSeries Development
Ulrich.Weigand@de.ibm.com