On Thu, Apr 17, 2025 at 09:48:45AM +0800, Feng Yang wrote: > From: Feng Yang <yangfeng@xxxxxxxxxx> > > 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. > > The fix reorders the fields to place the unique ID before the name. > This ensures that even if truncation occurs via snprintf, the unique ID > remains intact, preserving event name uniqueness. Additionally, explicit > checks with MAX_EVENT_NAME_LEN are added to enforce length constraints. > --- > Changes in v5: > - use strrchr instead of basename. > - kprobe_test add __weak. Thanks, Andrii Nakryiko! > - Link to v4: https://lore.kernel.org/all/20250415093907.280501-1-yangfeng59949@xxxxxxx/ Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> thanks, jirka > > Changes in v4: > - add changelog. > - gen_uprobe_legacy_event_name and gen_kprobe_legacy_event_name are combined into a function > - kprobe_test use normal module function. Thanks, Jiri Olsa! > - Link to v3: https://lore.kernel.org/bpf/20250414093402.384872-1-yangfeng59949@xxxxxxx/ > > 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@xxxxxxx/ > > Changes in v2: > - Use basename() and %.32s to fix. Thanks, Hengqi Chen! > - Link to v1: https://lore.kernel.org/all/20250410052712.206785-1-yangfeng59949@xxxxxxx/ > > 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 | 43 ++++------ > .../selftests/bpf/prog_tests/attach_probe.c | 84 +++++++++++++++++++ > .../selftests/bpf/test_kmods/bpf_testmod.c | 4 + > 3 files changed, 104 insertions(+), 27 deletions(-) > > -- > 2.43.0 >
