[PATCH v3 bpf-next 0/3] libbpf: Fix event name too long error and add tests

Feng Yang
2025-04-14T09:51:16Z

From: Feng Yang <yangfeng@kylinos.cn>

Hi everyone,

This series tries to fix event name too long error and add tests.

When the binary path is excessively long, the generated probe_name in libbpf
exceeds the kernel's MAX_EVENT_NAME_LEN limit (64 bytes).
This causes legacy uprobe event attachment to fail with error code -22.

---
Changes in v3:
- add __sync_fetch_and_add(&index) and let snprintf() do the trimming. Thanks, Andrii Nakryiko!
- add selftests.
- Link to v2: https://lore.kernel.org/all/20250411080545.319865-1-yangfeng59949@163.com/

Changes in v2:
- Use basename() and %.32s to fix. Thanks, Hengqi Chen!
- Link to v1: https://lore.kernel.org/all/20250410052712.206785-1-yangfeng59949@163.com/

Feng Yang (3):
libbpf: Fix event name too long error
selftests/bpf: Add test for attaching uprobe with long event names
selftests/bpf: Add test for attaching kprobe with long event names

tools/lib/bpf/libbpf.c | 19 +++--
.../selftests/bpf/prog_tests/attach_probe.c | 84 +++++++++++++++++++
.../selftests/bpf/test_kmods/bpf_testmod.c | 5 ++
.../bpf/test_kmods/bpf_testmod_kfunc.h | 2 +
4 files changed, 103 insertions(+), 7 deletions(-)

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2.43.0