This proposal builds upon the discussion in "[PATCH bpf-next v4 0/4] bpf: Improve error reporting for freplace attachment failure"[1], and is also relevant to ongoing efforts such as tracing multi-link attach failures[2]. This patch set introduces support for *common attributes* in the 'bpf()' syscall, providing a unified mechanism for passing shared metadata across all BPF commands. The initial set of common attributes includes: 1. 'log_buf': User-provided buffer for storing log output. 2. 'log_size': Size of the provided log buffer. 3. 'log_level': Verbosity level for logging. With this extension, the 'bpf()' syscall will be able to return meaningful error messages (e.g., when a 'freplace' program fails to attach), improving debuggability and user experience. Links: [1] https://lore.kernel.org/bpf/20250224153352.64689-1-leon.hwang@xxxxxxxxx/ [2] https://lore.kernel.org/bpf/20250703121521.1874196-1-dongml2@xxxxxxxxxxxxxxx/ Leon Hwang (5): bpf: Extend bpf syscall with common attributes support libbpf: Add support for extended bpf syscall bpf: Report freplace attach failure reason via extended syscall libbpf: Capture error message on freplace attach failure selftests/bpf: Add case to test freplace attach failure log include/uapi/linux/bpf.h | 7 +++ kernel/bpf/syscall.c | 58 +++++++++++++++---- tools/include/uapi/linux/bpf.h | 7 +++ tools/lib/bpf/bpf.c | 58 ++++++++++++++++++- tools/lib/bpf/bpf.h | 3 + tools/lib/bpf/features.c | 8 +++ tools/lib/bpf/libbpf.c | 18 ++++-- tools/lib/bpf/libbpf.h | 4 ++ tools/lib/bpf/libbpf.map | 3 + tools/lib/bpf/libbpf_internal.h | 2 + .../bpf/prog_tests/tracing_failure.c | 43 ++++++++++++++ 11 files changed, 193 insertions(+), 18 deletions(-) -- 2.50.1
