Re: [RFA/commit] arm-tdep.c: Do not single-step after hitting a watchpoint.

Luis Machado
2014-09-16T12:05:54Z

On 09/16/2014 08:59 AM, Joel Brobecker wrote:
>> Can you elaborate your experiments? Do you do experiments on qemu, arm
>> bare metal targets or arm linux targets?
>
> My experiments were on QEMU, but others tried on bare-metal. I tried
> on GNU/Linux targets as well, but hardware watchpoints simply did
> not work (no signal).
>
>> I find Peter tries to fix the same problem we encounter in qemu side,
>>
>> [Qemu-devel] [PATCH] gdbstub: Allow target CPUs to specify watchpoint STOP_BEFORE_ACCESS flag
>> http://lists.nongnu.org/archive/html/qemu-devel/2014-09/msg02665.html
>>
>> and this patch isn't accepted yet.
> [...]
>> Note that with patched qemu, two fails in gdb.base/recurse.exp are
>> fixed. At least, gdb and qemu should be in sync on this.
>
> I think the experiments that were run showed that QEMU is in fact
> correct and should NOT be changed.
>

Do we know what the Linux kernel's behavior on this one is? I wonder
what the stopped data address shows.

Someone with access to a board with a relatively new kernel could try
that and rule it out, otherwise we risk fixing something for QEMU/bare
metal and breaking things for Linux.

Luis