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

[liwei (GF)]

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! :-)

Thanks,
Wei