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

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