On Thu, 26 Apr 2018 22:12:16 +0200, Jan Kratochvil wrote:
> On Fri, 20 Apr 2018 16:49:39 +0200, Pedro Alves wrote:
> > ~~~~~~~~~~~~
> > Previously, when the hardware reported a watchpoint hit on an address
> > that did not match our watchpoint (this happens in case of instructions
> > which access large chunks of memory such as "stp") the process would
> > enter a loop where we would be continually resuming it (because we did
> > not recognise that watchpoint hit) and it would keep hitting the
> > watchpoint again and again. The tracing process would never get
> > notified of the watchpoint hit.
> > ~~~~~~~~~~~~
> > 
> > ... I'm left with the impression that ADDR_TRAP could be even
> > lower than addr_watch_aligned, in which case we'll still miss
> > watchpoints.  I wondering whether GDB should be using a similar
> > trick as that kernel patch does.
> 
> This is new for me what you found.  I just did not expect the changed region
> region could be larger than aligned 8 bytes.
> 
> Unfortunately I cannot reproduce that so I cannot do much with that.
> Does anyone know how to reproduce it?

Attaching the change I made, I will repost the patch in a next mail.


Jan