On Thu, May 27, 2021 at 04:18:15PM +0800, Tiezhu Yang wrote:

On 05/27/2021 12:24 PM, Greg Kroah-Hartman wrote:

quoted

On Thu, May 27, 2021 at 10:27:51AM +0800, Tiezhu Yang wrote:

quoted

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.

quoted

(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

I compared the related code in 4.19.y and upstream mainline, some failures
disappeared after add ".flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,", but
other failures still exist, and I didn't have enough in-depth knowledge to
touch things elsewhere.

The failures can be easily reproduced, I would greatly appreciate it if
anyone
is interested to fix them.

Sounds like you are interested, why not work on this instead of waiting
for someone else?  It's not like many people are interested in 4.19 at
this point in time.

good luck!

greg k-h