Greetings, while developing a patch to perform introspection on KVM[1], i'm facing a bug where a call to pthread_sigmask(), coming from the libvirt client library, hangs for no obvious reason[2].
I come to ask for help and guidance on this mailing list, as i don't know how to proceed further. In fact: - the bug can only be triggered on a bare metal server in public cloud, i was unable to reproduce it anywhere else, including a VM. - given that the server is in public cloud, debugging with KGDB is impossible since it requires 2 computers with a serial cable (as i understood) After a few discussions on the Libvirt mailing list, they suggested the bug was due to a memory corruption. it's a possibility, but very unlickely as I would have seen unexpected crashes everywhere else. The kernel i'm using is a modified Debian Stretch kernel. The next step for me is to understand where the call is blocked in the kernel, and I would like to ask you what are my solutions to get a kernel backtrace of my process in this situation ? [1]: https://github.com/KVM-VMI/kvm-vmi [2]: https://gist.github.com/Wenzel/6dc9e32558a7ffd51d1c0d89177532fc Thank you for your time, Best regards -- Mathieu Tarral
