Subject: Re: [QUESTION] BPF kernel selftests failed in the LTS stable kernel 4.19.x

From: Greg Kroah-Hartman <[email-masked]>
Date: Thu, 27 May 2021 06:24:26 +0200

On Thu, May 27, 2021 at 10:27:51AM +0800, Tiezhu Yang wrote:
> Hi all,
> 
> When update the following LTS stable kernel 4.19.x,
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/log/?h=linux-4.19.y
> 
> and then run BPF selftests according to
> https://www.kernel.org/doc/html/latest/bpf/bpf_devel_QA.html#q-how-to-run-bpf-selftests
> 
> $ cd tools/testing/selftests/bpf/
> $ make
> $ sudo ./test_verifier
> $ sudo make run_tests
> 
> there exists many failures include verifier tests and run_tests,
> (1) is it necessary to make sure that there are no any failures in the LTS
> stable kernel 4.19.x?

Yes, it would be nice if that did not happen.

> (2) if yes, how to fix these failures in the LTS stable kernel 4.19.x?

Can you find the offending commits by using `git bisect` and find the
upstream commits that resolve this and let us know so we can backport
them?

thanks,

greg k-h