[v5,bpf-next,0/2] bpf: Fix fill_link_info and add selftest

Message

Yafang Shao Aug. 11, 2023, 2:36 a.m. UTC

Patch #1: Fix an error in fill_link_info reported by Dan
Patch #2: Add selftest for #1

v4->v5:
  - Comments from Yonghong
    - Replace 'offset' with '0'
    - Set err=-1 for default case
    - Only check return value of verify_kmulti_link_info
  - Comments from Jiri
    - Avoid retprobe argument
    - Use bpf_fentry_test* instead
    - Rename verify_kmulti_user_buffer
  - Define some variables as global value to simplify the code

v3->v4:
  - Comments from Yonghong
    - re-word the kptr comment
    - Avoid unnecessary switch statement
    - No need to check the return value of bpf_link__fd()
    - offset is always 0
    - Return directly when test_fill_link_info__open_and_load() fails
    - Cleanup skel when load_kallsyms_refresh() fails

v2->v3:
  - Comments from Jiri
    - Verify wrong arguments as soon as possible
    - Use CONFIG_X86_KERNEL_IBT
    - No need to make the test serial
    - Add test case for kprobe_multi

v1->v2:
  - Fix BPF CI failure due to the enabled ENDBDR

Yafang Shao (2):
  bpf: Fix uninitialized symbol in bpf_perf_link_fill_kprobe()
  selftests/bpf: Add selftest for fill_link_info

 kernel/bpf/syscall.c                               |   4 +-
 tools/testing/selftests/bpf/DENYLIST.aarch64       |   3 +
 .../selftests/bpf/prog_tests/fill_link_info.c      | 342 +++++++++++++++++++++
 .../selftests/bpf/progs/test_fill_link_info.c      |  42 +++
 4 files changed, 389 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/fill_link_info.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_fill_link_info.c