Commit Graph
3 Commits
Author SHA1 Message Date
Jiawei Zhao fcc06c3da4 libbpf: Remove unused args in parse_usdt_note
Remove unused 'elf' and 'path' parameters from parse_usdt_note function
signature. These parameters are not referenced within the function body
and only add unnecessary complexity.

The function only requires the note header, data buffer, offsets, and
output structure to perform USDT note parsing.

Update function declaration, definition, and the single call site in
collect_usdt_targets() to match the simplified signature.

This is a safe internal cleanup as parse_usdt_note is a static function.

Signed-off-by: Jiawei Zhao <phoenix500526@163.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250904030525.1932293-1-phoenix500526@163.com
2025-10-06 15:59:27 -07:00
Jiawei Zhao 9236e137e9 libbpf: Fix USDT SIB argument handling causing unrecognized register error
On x86-64, USDT arguments can be specified using Scale-Index-Base (SIB)
addressing, e.g. "1@-96(%rbp,%rax,8)". The current USDT implementation
in libbpf cannot parse this format, causing `bpf_program__attach_usdt()`
to fail with -ENOENT (unrecognized register).

This patch fixes this by implementing the necessary changes:
- add correct handling for SIB-addressed arguments in `bpf_usdt_arg`.
- add adaptive support to `__bpf_usdt_arg_type` and
  `__bpf_usdt_arg_spec` to represent SIB addressing parameters.

Signed-off-by: Jiawei Zhao <phoenix500526@163.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250827053128.1301287-2-phoenix500526@163.com
2025-10-06 15:59:27 -07:00
Jiawei Zhao 224ea3ec50 libbpf: Correct some typos and syntax issues in usdt doc
Fix some incorrect words, such as "and" -> "an", "it's" -> "its".  Fix
some grammar issues, such as removing redundant "will", "would
complicated" -> "would complicate".

Signed-off-by: Jiawei Zhao <Phoenix500526@163.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250531095111.57824-1-Phoenix500526@163.com
2025-06-16 08:52:44 -07:00