This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [PATCH 2/2] Enable range stepping for ARM on GDBServer
- From: Antoine Tremblay <antoine dot tremblay at ericsson dot com>
- To: Yao Qi <qiyaoltc at gmail dot com>
- Cc: Pedro Alves <palves at redhat dot com>, Antoine Tremblay <antoine dot tremblay at ericsson dot com>, "gdb-patches at sourceware dot org" <gdb-patches at sourceware dot org>
- Date: Thu, 1 Sep 2016 13:05:54 -0400
- Subject: Re: [PATCH 2/2] Enable range stepping for ARM on GDBServer
- Authentication-results: sourceware.org; auth=none
- References: <20160831171406.24057-1-antoine.tremblay@ericsson.com> <20160831171406.24057-2-antoine.tremblay@ericsson.com> <b5bc1e35-1840-a7ab-6392-cb29c4ee4b8f@redhat.com> <wwokwpiwyfct.fsf@ericsson.com> <3fdb7193-60c7-49c9-ccf5-bc040aa157ea@redhat.com> <wwoktwe0ycml.fsf@ericsson.com> <a44c8554-cc86-6ed1-b5cf-0697189eca73@redhat.com> <wwokr393hchh.fsf@ericsson.com> <fb926e69-f730-1659-668d-93d3b7453306@redhat.com> <CAH=s-PN-T_VVrjF2tf71wD15mLALEHbd3Wy_DA2duDrFYnqXmQ@mail.gmail.com>
Yao Qi writes:
> [sigh, I am testing my arm range stepping patches today...]
>
Thanks for working on this :)
> On Thu, Sep 1, 2016 at 4:59 PM, Pedro Alves <palves@redhat.com> wrote:
>>>>
>>>>> I'm sorry I can't be more helpful at the moment but I wanted to post
>>>>> this issue before I have to leave for a while.
>>>>
>>>> Understood. Does enabling range stepping unblock something else?
>>>
>>> It would unblock ARM tracepoints, as per Yao's requirements...
>>
>> Tracepoints make gdbserver single-step and then not report the event
>> to gdb, so I do see the parallel with range-stepping. Throwing
>> while-stepping into the equation would make it even more clear.
>>
>
> Range-stepping makes gdbserver single-step and then not report the event
> to gdb if thread pc is within the range. It is similar to tracepoint, but much
> simpler.
>
> Both range-stepping and tracepoing needs to remove reinsert_breakpoint
> when gdbserver gets an event but doesn't report it back to gdb. However,
> gdbserver doesn't do so now. That is the reason I believe we need to
> support range-stepping first, and I am working on this (but interrupted by
> 7.12 release). The draft patch attached removes reinsert_breakpoint when
> gdbserver gets an event but not to report it back to gdb.
>
OK
> Beside "removing reinsert_breakpoint on gdbserver internal event", we'd
> better to think that "each backend unwinders don't have to worry about
> unavailable data". I posted a draft here
> https://sourceware.org/ml/gdb-patches/2016-05/msg00060.html, I need
> some review comments. Pedro,
> can you take a look? This is not a hard requirement for ARM tracepoint
> support.
Thanks for not making this one a hard requirement!
Regards,
Antoine