On Thu, Sep 25, 2025 at 2:36 AM Mehdi Ben Hadj Khelifa
[off-list ref] wrote:

This series is preparing to add the -Wsign-compare C compilation flag to
the Makefile for bpf selftests as requested by a TODO to help avoid
implicit type conversions and have predictable behavior.

Changelog:

Changes from v2:

-Split up the patch into a patch series as suggested by vivek

-Include only changes to variable types with no casting by my mentor
david

-Removed the -Wsign-compare in Makefile to avoid compilation errors
until adding casting for rest of comparisons.

Link:https://lore.kernel.org/bpf/20250924195731.6374-1-mehdi.benhadjkhelifa@gmail.com/T/#u (local)

Changes from v1:

- Fix CI failed builds where it failed due to do missing .c and
.h files in my patch for working in mainline.

Link:https://lore.kernel.org/bpf/20250924162408.815137-1-mehdi.benhadjkhelifa@gmail.com/T/#u (local)

Mehdi Ben Hadj Khelifa (3):
  selftests/bpf: Prepare to add -Wsign-compare for bpf tests
  selftests/bpf: Prepare to add -Wsign-compare for bpf tests
  selftests/bpf: Prepare to add -Wsign-compare for bpf tests

I see little value in these transformations. Did we catch any real
issue here? All this type casting and replacement is just churn.

I certainly don't want such churn in libbpf, and I'd leave BPF
selftests as is as well. int vs u64 can have subtle and non-obvious
implications for BPF code generation (for no-alu32 variants
especially), and I think BPF CI already exposed some of those already.

I think we can live without -Wsign-compare just fine.

 tools/testing/selftests/bpf/progs/test_global_func11.c       | 2 +-
 tools/testing/selftests/bpf/progs/test_global_func12.c       | 2 +-
 tools/testing/selftests/bpf/progs/test_global_func13.c       | 2 +-
 tools/testing/selftests/bpf/progs/test_global_func9.c        | 2 +-
 tools/testing/selftests/bpf/progs/test_map_init.c            | 2 +-
 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c   | 2 +-
 .../selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c      | 2 +-
 tools/testing/selftests/bpf/progs/test_skb_ctx.c             | 2 +-
 tools/testing/selftests/bpf/progs/test_snprintf.c            | 2 +-
 tools/testing/selftests/bpf/progs/test_sockmap_strp.c        | 2 +-
 tools/testing/selftests/bpf/progs/test_tc_tunnel.c           | 2 +-
 tools/testing/selftests/bpf/progs/test_xdp.c                 | 2 +-
 tools/testing/selftests/bpf/progs/test_xdp_dynptr.c          | 2 +-
 tools/testing/selftests/bpf/progs/test_xdp_loop.c            | 2 +-
 tools/testing/selftests/bpf/progs/test_xdp_noinline.c        | 4 ++--
 tools/testing/selftests/bpf/progs/uprobe_multi.c             | 4 ++--
 .../selftests/bpf/progs/uprobe_multi_session_recursive.c     | 5 +++--
 .../selftests/bpf/progs/verifier_iterating_callbacks.c       | 2 +-
 18 files changed, 22 insertions(+), 21 deletions(-)

--
2.51.0