[minicoredumper] stack detection fails with kernel >= v5.18

[Holger Brunck]

Hello all,

> I currently try to integrate the minicoredumper into our embedded SW. I am
> using the latest version 2.06. With kernel 5.4.x it works pretty well. But with
> boards using kernel 6.1.x I saw problems. The stacks were missing in the
> generated core file from the minicoredumper.
> Our application is multithreaded and minicoredumper reports when processing
> the core file:
> Aug 15 08:18:45 unit user.err minicoredumper: unable to find thread #14's (386)
> stack Aug 15 08:18:45 unit user.err minicoredumper: unable to find thread #15's
> (387) stack Aug 15 08:18:45 unit user.err minicoredumper: unable to find thread
> #16's (388) stack Aug 15 08:18:45 unit user.err minicoredumper: unable to find
> thread #17's (389) stack
> 
> I was able to reproduce this problem in a x86 qemu environment with a mainline
> kernel and parts of our application code. After bisecting the kernel I saw that
> this was introduced with kernel v5.15 due to the following commit:
> 7b1b610f  coredump:  Don't perform any cleanups before dumping core
> 
> Btw when using the regular core file gdb is able to show the stacks from the
> threads as expected.
> 
> Any ideas what might be the problem in the minicoredumper so that the stacks
> can't be detected properly anymore? Are there any ideas how to fix this?
> 

is anyone using the minicoredumper on a recent kernel with a multithreaded
application successfully? Any help is appreciated.

Best regards
Holger