kernel/linux.git/tools/lib/bpf/usdt.c, branch linux-7.1.y

libbpf: Add support to detect nop,nop5 instructions combo for usdt probe

2026-03-03T16:39:22+00:00

Adding support to detect nop,nop5 instructions combo for usdt probe by checking on probe's following nop5 instruction. When the nop,nop5 combo is detected together with uprobe syscall, we can place the probe on top of nop5 and get it optimized. Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20260224103915.1369690-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

tools: Remove s390 compat support

2025-11-17T10:10:38+00:00

Remove s390 compat support from everything within tools, since s390 compat support will be removed from the kernel. Reviewed-by: Arnd Bergmann Acked-by: Thomas Weißschuh # tools/nolibc selftests/nolibc Reviewed-by: Thomas Weißschuh # selftests/vDSO Acked-by: Alexei Starovoitov # bpf bits Signed-off-by: Heiko Carstens

libbpf: move libbpf_errstr() into libbpf_utils.c

2025-10-01T22:27:25+00:00

Get rid of str_err.{c,h} by moving implementation of libbpf_errstr() into libbpf_utils.c and declarations into libbpf_internal.h. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20251001171326.3883055-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov Acked-by: Eduard Zingerman

libbpf: Remove unused args in parse_usdt_note

2025-09-04T18:35:44+00:00

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 Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20250904030525.1932293-1-phoenix500526@163.com

libbpf: Fix USDT SIB argument handling causing unrecognized register error

2025-08-27T22:44:25+00:00

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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250827053128.1301287-2-phoenix500526@163.com

libbpf: Correct some typos and syntax issues in usdt doc

2025-06-05T18:45:48+00:00

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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250531095111.57824-1-Phoenix500526@163.com

libbpf: don't adjust USDT semaphore address if .stapsdt.base addr is missing

2024-12-02T16:41:17+00:00

USDT ELF note optionally can record an offset of .stapsdt.base, which is used to make adjustments to USDT target attach address. Currently, libbpf will do this address adjustment unconditionally if it finds .stapsdt.base ELF section in target binary. But there is a corner case where .stapsdt.base ELF section is present, but specific USDT note doesn't reference it. In such case, libbpf will basically just add base address and end up with absolutely incorrect USDT target address. This adjustment has to be done only if both .stapsdt.sema section is present and USDT note is recording a reference to it. Fixes: 74cc6311cec9 ("libbpf: Add USDT notes parsing and resolution logic") Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20241121224558.796110-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Stringify errno in log messages in the remaining code

2024-11-12T04:29:45+00:00

Convert numeric error codes into the string representations in log messages in the rest of libbpf source files. Signed-off-by: Mykyta Yatsenko Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20241111212919.368971-5-mykyta.yatsenko5@gmail.com

libbpf: Add uprobe multi link support to bpf_program__attach_usdt

2023-08-21T22:51:26+00:00

Adding support for usdt_manager_attach_usdt to use uprobe_multi link to attach to usdt probes. The uprobe_multi support is detected before the usdt program is loaded and its expected_attach_type is set accordingly. If uprobe_multi support is detected the usdt_manager_attach_usdt gathers uprobes info and calls bpf_program__attach_uprobe to create all needed uprobes. If uprobe_multi support is not detected the old behaviour stays. Also adding usdt.s program section for sleepable usdt probes. Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20230809083440.3209381-18-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Add elf_open/elf_close functions

2023-08-21T22:51:26+00:00

Adding elf_open/elf_close functions and using it in elf_find_func_offset_from_file function. It will be used in following changes to save some common code. Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20230809083440.3209381-10-jolsa@kernel.org Signed-off-by: Alexei Starovoitov