[Disco/Eoan] LP: #1862588

[Thadeu Lima de Souza Cascardo]

[Impact]
Running seccomp kernel selftests will fail.

[Test case]
Run linux/tools/testing/selftests/seccomp/seccomp_bpf.

On failure:

seccomp_bpf.c:3149:global.user_notification_basic:Expected -1 (18446744073709551615) == ret (0)
seccomp_bpf.c:3150:global.user_notification_basic:Expected EINVAL (22) == errno (0)
global.user_notification_basic: Test failed at step #3
[ FAIL ] global.user_notification_basic

On success:

[ RUN ] global.user_notification_basic
[ OK ] global.user_notification_basic

[Regression potential]
The test is checking that the given structure which the kernel will write to is
all zeroes. It's doing it because it wants userspace to have the possibility in
the future to give data there indicating support for an extension that might be
developed in the future. As the test is there right now, not applying the
breaking uABI fix might cause us to miss applications that would break in
future kernels. As the backport for that is prone for more regression
potential, we are deciding to revert the new test.