diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-08-15 09:06:03 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-17 00:45:08 +0200 |
| commit | 3ec84f4b1638495ebff068a668dc417b4de5727e (patch) | |
| tree | d3f711331cd4c4fd2ecd7c01cd68316ec81c3399 /tools/lib/bpf/bpf.c | |
| parent | libbpf: Use BPF perf link when supported by kernel (diff) | |
| download | linux-3ec84f4b1638495ebff068a668dc417b4de5727e.tar.xz linux-3ec84f4b1638495ebff068a668dc417b4de5727e.zip | |
libbpf: Add bpf_cookie support to bpf_link_create() API
Add ability to specify bpf_cookie value when creating BPF perf link with
bpf_link_create() low-level API.
Given BPF_LINK_CREATE command is growing and keeps getting new fields that are
specific to the type of BPF_LINK, extend libbpf side of bpf_link_create() API
and corresponding OPTS struct to accomodate such changes. Add extra checks to
prevent using incompatible/unexpected combinations of fields.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-11-andrii@kernel.org
Diffstat (limited to 'tools/lib/bpf/bpf.c')
| -rw-r--r-- | tools/lib/bpf/bpf.c | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 86dcac44f32f..2401fad090c5 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -684,8 +684,13 @@ int bpf_link_create(int prog_fd, int target_fd, iter_info_len = OPTS_GET(opts, iter_info_len, 0); target_btf_id = OPTS_GET(opts, target_btf_id, 0); - if (iter_info_len && target_btf_id) - return libbpf_err(-EINVAL); + /* validate we don't have unexpected combinations of non-zero fields */ + if (iter_info_len || target_btf_id) { + if (iter_info_len && target_btf_id) + return libbpf_err(-EINVAL); + if (!OPTS_ZEROED(opts, target_btf_id)) + return libbpf_err(-EINVAL); + } memset(&attr, 0, sizeof(attr)); attr.link_create.prog_fd = prog_fd; @@ -693,14 +698,27 @@ int bpf_link_create(int prog_fd, int target_fd, attr.link_create.attach_type = attach_type; attr.link_create.flags = OPTS_GET(opts, flags, 0); - if (iter_info_len) { - attr.link_create.iter_info = - ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); - attr.link_create.iter_info_len = iter_info_len; - } else if (target_btf_id) { + if (target_btf_id) { attr.link_create.target_btf_id = target_btf_id; + goto proceed; } + switch (attach_type) { + case BPF_TRACE_ITER: + attr.link_create.iter_info = ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); + attr.link_create.iter_info_len = iter_info_len; + break; + case BPF_PERF_EVENT: + attr.link_create.perf_event.bpf_cookie = OPTS_GET(opts, perf_event.bpf_cookie, 0); + if (!OPTS_ZEROED(opts, perf_event)) + return libbpf_err(-EINVAL); + break; + default: + if (!OPTS_ZEROED(opts, flags)) + return libbpf_err(-EINVAL); + break; + } +proceed: fd = sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr)); return libbpf_err_errno(fd); } |