Re: [RFA]: Fix for watchpoint regressions

[Ulrich Weigand <Ulrich.Weigand@de.ibm.com>]

Jeff Johnston wrote:

>Things worked in the past for ia64 because the code near the bottom of the
loop
>in bpstat_stop_status would check whether a hardware watchpoint value had
>changed.  With Ulrich's original patch in place, this never happens
because we
>never get to that piece of code in the loop.  With the revised patch, for
the
>original scenario that Ulrich was fixing, we will not get to the
watchpoint
>checking code, but for platforms that do not have
HAVE_CONTINUABLE_WATCHPOINT,
>we will.  We won't yet be able to handle the breakpoint insn in code
scenario
>for ia64 that Ulrich was fixing, but that is a separate fix.

Note that my patch wasn't the first in the sequence; I only tried to fix
s390 breakage caused by the original patch (by Orjan Friberg) ...

In the past, we'd indeed always check for hardware watchpoints by comparing
all memory locations for changes.  It was not my patch that changed this,
but Orjan's http://sources.redhat.com/ml/gdb-patches/2004-04/msg00521.html.
That patch was the one that tried to fix the breakpoint in code scenario.

This caused breakage on s390 because that patch unconditionally used
target_stopped_data_address; but s390 is unable to provide that info.
My change was to simply use STOPPED_BY_WATCHPOINT instead to provide
that single bit of information actually required.


But anyway, as far as s390 is concerned your patch should make no
difference, so I have no objections to it ...


Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

--
  Dr. Ulrich Weigand
  Linux for S/390 Design & Development
  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
  Phone: +49-7031/16-3727   ---   Email: Ulrich.Weigand@de.ibm.com