Re: [PATCH 0/4] Support tracepoints for ARM linux in GDBServer

Yao Qi
2016-04-27T08:00:04Z

Antoine Tremblay <antoine.tremblay@ericsson.com> writes:

> From what I can tell issue 1) is about done ?
>

There are still some things we need to do before arm tracepoint support,
and I am working on them,

- really exercise the software single step in gdbserver,
1. software single step over instruction branch to itself. [DONE]
2. force gdb to use vCont;s for gdbserver using software single step,
IOW, let gdbserver handle single step requested by gdb,
3. turn range stepping on on arm linux,

I have some patches in my tree. After these steps, we are confident
that software single step in gdbserver is reliable.

> On my end we have fast tracepoints for arm almost ready with JIT
> conditions and pc relative instructions relocation.
>
> I would like to post that in the next few weeks, but it would be
> better if the normal tracepoints were in before that.
>
> Is it a good time to review these patches now?

- handle unavailable memory/register in frame unwinding in target
independent part, so that we don't have to worry about the
unavailable memory in arm backend.
I am writing a prototype according to Pedro's thoughts,
https://sourceware.org/ml/gdb-patches/2016-02/msg00778.html
but it is blocked by a patch related PR 19947,
https://sourceware.org/ml/gdb-patches/2016-04/msg00429.html
we need an approach to test each unwinder, the discussion is still
ongoing.

I won't review arm tracepoint patches until all of them above are
fixed.

--
Yao (齐尧)