diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-08-15 00:06:08 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-17 00:45:08 +0200 |
| commit | 5e3b8356de3623987ace530b1977ffeb9ecf5a8a (patch) | |
| tree | 290b81ae84bd5819db142c6da14c8502ae20c3b0 /tools/lib/bpf/libbpf.h | |
| parent | 0a80cf67f34cab7c18d74c28bb59e131670dc268 (diff) | |
libbpf: Add uprobe ref counter offset support for USDT semaphores
When attaching to uprobes through perf subsystem, it's possible to specify
offset of a so-called USDT semaphore, which is just a reference counted u16,
used by kernel to keep track of how many tracers are attached to a given
location. Support for this feature was added in [0], so just wire this through
uprobe_opts. This is important to enable implementing USDT attachment and
tracing through libbpf's bpf_program__attach_uprobe_opts() API.
[0] a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-16-andrii@kernel.org
Diffstat (limited to 'tools/lib/bpf/libbpf.h')
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 1f4a67285365..f177d897c5f7 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -284,6 +284,10 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog, struct bpf_uprobe_opts { /* size of this struct, for forward/backward compatiblity */ size_t sz; + /* offset of kernel reference counted USDT semaphore, added in + * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") + */ + size_t ref_ctr_offset; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; /* uprobe is return probe, invoked at function return time */ |