[Patch bpf v3 0/4] bpf: a bug fix and test cases for bpf_skb_change_tail()

[Cong Wang <xiyou.wangcong@gmail.com>]

From: Cong Wang <cong.wang@bytedance.com>

This patchset fixes a bug in bpf_skb_change_tail() helper and adds test
cases for it, as requested by Daniel and John.

---
v3: switched to TCX prog attaching API
    switched to UDP from TCP for TC test
    cleaned up TC test code

v2: added a test case for TC where offsets are positive
    fixed a typo in 1/4 patch description
    reduced buffer size in the sockmap test case

Cong Wang (4):
  bpf: Check negative offsets in __bpf_skb_min_len()
  selftests/bpf: Add a BPF selftest for bpf_skb_change_tail()
  selftests/bpf: Introduce socket_helpers.h for TC tests
  selftests/bpf: Test bpf_skb_change_tail() in TC ingress

 net/core/filter.c                             |  21 +-
 .../selftests/bpf/prog_tests/socket_helpers.h | 394 ++++++++++++++++++
 .../selftests/bpf/prog_tests/sockmap_basic.c  |  51 +++
 .../bpf/prog_tests/sockmap_helpers.h          | 385 +----------------
 .../selftests/bpf/prog_tests/tc_change_tail.c |  62 +++
 .../bpf/progs/test_sockmap_change_tail.c      |  40 ++
 .../selftests/bpf/progs/test_tc_change_tail.c | 106 +++++
 7 files changed, 669 insertions(+), 390 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/socket_helpers.h
 create mode 100644 tools/testing/selftests/bpf/prog_tests/tc_change_tail.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_change_tail.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_tc_change_tail.c

-- 
2.34.1