Re: [PATCH 0/4] arm64: kgdb/kdb: Fix single-step debugging issues

From: liwei (GF)
Date: Mon Jul 06 2020 - 21:37:11 EST


Hi Doug,

On 2020/6/30 5:20, Doug Anderson wrote:
> Wei,
>
> On Sat, May 16, 2020 at 1:20 AM liwei (GF) <liwei391@xxxxxxxxxx> wrote:
>>
>> Hi Douglas,
>>
>> On 2020/5/14 8:34, Doug Anderson wrote:
>>> Hi,
>>>
>>> On Sat, May 9, 2020 at 6:49 AM Wei Li <liwei391@xxxxxxxxxx> wrote:
>>>>
>>>> This patch set is to fix several issues of single-step debugging
>>>> in kgdb/kdb on arm64.
>>>>
>>>> It seems that these issues have been shelved a very long time,
>>>> but i still hope to solve them, as the single-step debugging
>>>> is an useful feature.
>>>>
>>>> Note:
>>>> Based on patch "arm64: cacheflush: Fix KGDB trap detection",
>>>> https://www.spinics.net/lists/arm-kernel/msg803741.html
>>>>
>>>> Wei Li (4):
>>>> arm64: kgdb: Fix single-step exception handling oops
>>>> arm64: Extract kprobes_save_local_irqflag() and
>>>> kprobes_restore_local_irqflag()
>>>> arm64: kgdb: Fix single-stepping into the irq handler wrongly
>>>> arm64: kgdb: Set PSTATE.SS to 1 to reenable single-step
>>>>
>>>> arch/arm64/include/asm/debug-monitors.h | 6 ++++++
>>>> arch/arm64/kernel/debug-monitors.c | 28 ++++++++++++++++++++++++-
>>>> arch/arm64/kernel/kgdb.c | 16 +++++++++++---
>>>> arch/arm64/kernel/probes/kprobes.c | 28 ++-----------------------
>>>> 4 files changed, 48 insertions(+), 30 deletions(-)
>>>
>>> Just an overall note that I'm very happy that you posted this patch
>>> series! It's always been a thorn in my side that stepping and
>>> breakpoints were so broken on arm64 and I'm really excited that you're
>>> fixing them. Now I'll have to get in the habit of using kgdb for more
>>> than just debugging crashes and maybe I can use it more for exploring
>>> how functions work more. :-)
>>>> I'll also note that with your patch series I'm even seeing the "call"
>>> feature of gdb working now. That has always been terribly broken for
>>> me.
>>>
>> Thanks for reviewing and testing this series.
>> Enjoy exploring the kernel with kgdb/kdb! :-)
>
> I'm curious to know if you plan another spin. The feedback you
> received was fairly minor so it hopefully shouldn't be too hard. I'd
> very much like to get your patches landed and I'd be happy to try to
> address the feedback and spin them myself if you're no longer
> available for it.
>

Sorry for the long delay. I was busy on a project and missed some mail.
I did receive some feedback about typo or coding style before, so i was expecting
more comment about the logic or people just don't care about these. After all,
this issue has lived a very long time.

It's a good news to hear that Will has plan to solve these issues, i will
follow that to do my bit.
Before that, i can send the next version in this week.


Thanks,
Wei