Hi Kazu

Here are the latest patches for supporting to run bt command against a core dump with kernel stack overflow exception for arm64.

Please help to review and advise if any further change needed.

Tested bt command with options:

bt -a
bt -c 3

By the way, 'mach' command also updated to show overflow stacks info as same as IRQ stacks.


From: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@nec.com>
Sent: Wednesday, November 17, 2021 15:23
To: Hong Yang3 杨红 <hong.yang3@nio.com>
Cc: Discussion list for crash utility usage, maintenance and development <crash-utility@redhat.com>
Subject: RE: arm64: Support overflow stack panic
Attention: This email comes from outside of the company, please pay attention to the information security!

Hi Hong,

Thank you for the patch and sending it to this list.

-----Original Message-----
> Hi Crash
> I'll keep refining the patch before it get approved:

OK, so we will wait for the refined patch.


> 1.    Fix the error in arm64_overflow_stack_init() which saved the overflow stack address into
> ms->irqstacks[], which would cause bt command crash on other cpus. The normal IRQ stacks should be used
> for bt command for other cpus.
> 2.    In addition to unwind on the overflow stack, try to go through the IRQ stack to find more useful
> information
> Kernel stack overflow case would be rarely but I'd like to sharp the crash to cover this kind of issue.
> Best regards
> Hong
> ________________________________
> From: Hong Yang3 杨红
> Sent: Tuesday, November 16, 2021 9:55
> To: crash-utility@redhat.com <crash-utility@redhat.com>
> Subject: arm64: Support overflow stack panic
> Hi All
> When I was trying to open a core of an overflow stack panic result, the bt command caused a segment fault,
> after a while I figured out the overflow stack is not supported by crash utility.
> This patch is trying to initialize the overflow stack information on startup stage, and the bt command works
> as expected to dump the correct call trace in the overflow stack, currently  it only apply to arm64 target.
> I'm not sure if any other sub command also need to be fixed for full support for the overflow stack, please
> advise and I'll try to improve the patch.
> Thanks
> Hong YANG