diff options
author | Andrii Nakryiko <andrii@kernel.org> | 2021-08-15 00:06:04 -0700 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-17 00:45:08 +0200 |
commit | 47faff371755ba0f1ad76e2df7f5003377d974a5 (patch) | |
tree | fe153bf46bdcfd9db8f22cdcfd18b1ebba2ea3c4 /tools/lib | |
parent | 3ec84f4b1638495ebff068a668dc417b4de5727e (diff) |
libbpf: Add bpf_cookie to perf_event, kprobe, uprobe, and tp attach APIs
Wire through bpf_cookie for all attach APIs that use perf_event_open under the
hood:
- for kprobes, extend existing bpf_kprobe_opts with bpf_cookie field;
- for perf_event, uprobe, and tracepoint APIs, add their _opts variants and
pass bpf_cookie through opts.
For kernel that don't support BPF_LINK_CREATE for perf_events, and thus
bpf_cookie is not supported either, return error and log warning for user.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-12-andrii@kernel.org
Diffstat (limited to 'tools/lib')
-rw-r--r-- | tools/lib/bpf/libbpf.c | 78 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.h | 71 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.map | 3 |
3 files changed, 127 insertions, 25 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5dc15f5b4b78..62ce878cb8e0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9014,12 +9014,16 @@ static void bpf_link_perf_dealloc(struct bpf_link *link) free(perf_link); } -struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pfd) +struct bpf_link *bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd, + const struct bpf_perf_event_opts *opts) { char errmsg[STRERR_BUFSIZE]; struct bpf_link_perf *link; int prog_fd, link_fd = -1, err; + if (!OPTS_VALID(opts, bpf_perf_event_opts)) + return libbpf_err_ptr(-EINVAL); + if (pfd < 0) { pr_warn("prog '%s': invalid perf event FD %d\n", prog->name, pfd); @@ -9040,7 +9044,10 @@ struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pf link->perf_event_fd = pfd; if (kernel_supports(prog->obj, FEAT_PERF_LINK)) { - link_fd = bpf_link_create(prog_fd, pfd, BPF_PERF_EVENT, NULL); + DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts, + .perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0)); + + link_fd = bpf_link_create(prog_fd, pfd, BPF_PERF_EVENT, &link_opts); if (link_fd < 0) { err = -errno; pr_warn("prog '%s': failed to create BPF link for perf_event FD %d: %d (%s)\n", @@ -9050,6 +9057,12 @@ struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pf } link->link.fd = link_fd; } else { + if (OPTS_GET(opts, bpf_cookie, 0)) { + pr_warn("prog '%s': user context value is not supported\n", prog->name); + err = -EOPNOTSUPP; + goto err_out; + } + if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { err = -errno; pr_warn("prog '%s': failed to attach to perf_event FD %d: %s\n", @@ -9076,6 +9089,11 @@ err_out: return libbpf_err_ptr(err); } +struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pfd) +{ + return bpf_program__attach_perf_event_opts(prog, pfd, NULL); +} + /* * this function is expected to parse integer in the range of [0, 2^31-1] from * given file using scanf format string fmt. If actual parsed value is @@ -9184,8 +9202,9 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, struct bpf_link * bpf_program__attach_kprobe_opts(struct bpf_program *prog, const char *func_name, - struct bpf_kprobe_opts *opts) + const struct bpf_kprobe_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; unsigned long offset; @@ -9197,6 +9216,7 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog, retprobe = OPTS_GET(opts, retprobe, false); offset = OPTS_GET(opts, offset, 0); + pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, offset, -1 /* pid */); @@ -9206,7 +9226,7 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); return libbpf_err_ptr(pfd); } - link = bpf_program__attach_perf_event(prog, pfd); + link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); @@ -9261,14 +9281,22 @@ static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec, return link; } -struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, - bool retprobe, pid_t pid, - const char *binary_path, - size_t func_offset) +LIBBPF_API struct bpf_link * +bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid, + const char *binary_path, size_t func_offset, + const struct bpf_uprobe_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; int pfd, err; + bool retprobe; + + if (!OPTS_VALID(opts, bpf_uprobe_opts)) + return libbpf_err_ptr(-EINVAL); + + retprobe = OPTS_GET(opts, retprobe, false); + pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, func_offset, pid); @@ -9279,7 +9307,7 @@ struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); return libbpf_err_ptr(pfd); } - link = bpf_program__attach_perf_event(prog, pfd); + link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); @@ -9292,6 +9320,16 @@ struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, return link; } +struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, + bool retprobe, pid_t pid, + const char *binary_path, + size_t func_offset) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts, .retprobe = retprobe); + + return bpf_program__attach_uprobe_opts(prog, pid, binary_path, func_offset, &opts); +} + static int determine_tracepoint_id(const char *tp_category, const char *tp_name) { @@ -9342,14 +9380,21 @@ static int perf_event_open_tracepoint(const char *tp_category, return pfd; } -struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, - const char *tp_category, - const char *tp_name) +struct bpf_link *bpf_program__attach_tracepoint_opts(struct bpf_program *prog, + const char *tp_category, + const char *tp_name, + const struct bpf_tracepoint_opts *opts) { + DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; int pfd, err; + if (!OPTS_VALID(opts, bpf_tracepoint_opts)) + return libbpf_err_ptr(-EINVAL); + + pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + pfd = perf_event_open_tracepoint(tp_category, tp_name); if (pfd < 0) { pr_warn("prog '%s': failed to create tracepoint '%s/%s' perf event: %s\n", @@ -9357,7 +9402,7 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); return libbpf_err_ptr(pfd); } - link = bpf_program__attach_perf_event(prog, pfd); + link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts); err = libbpf_get_error(link); if (err) { close(pfd); @@ -9369,6 +9414,13 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, return link; } +struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, + const char *tp_category, + const char *tp_name) +{ + return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL); +} + static struct bpf_link *attach_tp(const struct bpf_sec_def *sec, struct bpf_program *prog) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 1271d99bb7aa..1f4a67285365 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -104,17 +104,6 @@ struct bpf_object_open_opts { }; #define bpf_object_open_opts__last_field btf_custom_path -struct bpf_kprobe_opts { - /* size of this struct, for forward/backward compatiblity */ - size_t sz; - /* function's offset to install kprobe to */ - unsigned long offset; - /* kprobe is return probe */ - bool retprobe; - size_t :0; -}; -#define bpf_kprobe_opts__last_field retprobe - LIBBPF_API struct bpf_object *bpf_object__open(const char *path); LIBBPF_API struct bpf_object * bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); @@ -255,24 +244,82 @@ LIBBPF_API int bpf_link__destroy(struct bpf_link *link); LIBBPF_API struct bpf_link * bpf_program__attach(struct bpf_program *prog); + +struct bpf_perf_event_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; +}; +#define bpf_perf_event_opts__last_field bpf_cookie + LIBBPF_API struct bpf_link * bpf_program__attach_perf_event(struct bpf_program *prog, int pfd); + +LIBBPF_API struct bpf_link * +bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd, + const struct bpf_perf_event_opts *opts); + +struct bpf_kprobe_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; + /* function's offset to install kprobe to */ + unsigned long offset; + /* kprobe is return probe */ + bool retprobe; + size_t :0; +}; +#define bpf_kprobe_opts__last_field retprobe + LIBBPF_API struct bpf_link * bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe, const char *func_name); LIBBPF_API struct bpf_link * bpf_program__attach_kprobe_opts(struct bpf_program *prog, const char *func_name, - struct bpf_kprobe_opts *opts); + const struct bpf_kprobe_opts *opts); + +struct bpf_uprobe_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; + /* uprobe is return probe, invoked at function return time */ + bool retprobe; + size_t :0; +}; +#define bpf_uprobe_opts__last_field retprobe + LIBBPF_API struct bpf_link * bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe, pid_t pid, const char *binary_path, size_t func_offset); LIBBPF_API struct bpf_link * +bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid, + const char *binary_path, size_t func_offset, + const struct bpf_uprobe_opts *opts); + +struct bpf_tracepoint_opts { + /* size of this struct, for forward/backward compatiblity */ + size_t sz; + /* custom user-provided value fetchable through bpf_get_attach_cookie() */ + __u64 bpf_cookie; +}; +#define bpf_tracepoint_opts__last_field bpf_cookie + +LIBBPF_API struct bpf_link * bpf_program__attach_tracepoint(struct bpf_program *prog, const char *tp_category, const char *tp_name); LIBBPF_API struct bpf_link * +bpf_program__attach_tracepoint_opts(struct bpf_program *prog, + const char *tp_category, + const char *tp_name, + const struct bpf_tracepoint_opts *opts); + +LIBBPF_API struct bpf_link * bpf_program__attach_raw_tracepoint(struct bpf_program *prog, const char *tp_name); LIBBPF_API struct bpf_link * diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 58e0fb2c482f..bbc53bb25f68 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -374,6 +374,9 @@ LIBBPF_0.5.0 { bpf_map__pin_path; bpf_map_lookup_and_delete_elem_flags; bpf_program__attach_kprobe_opts; + bpf_program__attach_perf_event_opts; + bpf_program__attach_tracepoint_opts; + bpf_program__attach_uprobe_opts; bpf_object__gen_loader; btf__load_from_kernel_by_id; btf__load_from_kernel_by_id_split; |