Merge branch 'bpf-flow-dissector-tests'

Stanislav Fomichev says:

====================
This patch series adds support for testing flow dissector BPF programs
by extending already existing BPF_PROG_TEST_RUN. The goal is to have
a packet as an input and `struct bpf_flow_key' as an output. That way
we can easily test flow dissector programs' behavior. I've also modified
existing test_progs.c test to do a simple flow dissector run as well.

* first patch introduces new __skb_flow_bpf_dissect to simplify
  sharing between __skb_flow_bpf_dissect and BPF_PROG_TEST_RUN
* second patch adds actual BPF_PROG_TEST_RUN support
* third patch adds example usage to the selftests

v3:
* rebased on top of latest bpf-next

v2:
* loop over 'kattr->test.repeat' inside of
  bpf_prog_test_run_flow_dissector, don't reuse
  bpf_test_run/bpf_test_run_one
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>