libbpf: Export bpf_program__attach_kprobe_opts function

Export bpf_program__attach_kprobe_opts as a public API.

Rename bpf_program_attach_kprobe_opts to bpf_kprobe_opts and turn it into OPTS
struct.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20210721215810.889975-4-jolsa@kernel.org

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 52f4f1d..e595816 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10366,25 +10366,28 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
        return pfd;
 }
 
-struct bpf_program_attach_kprobe_opts {
-       bool retprobe;
-       unsigned long offset;
-};
-
-static struct bpf_link*
+struct bpf_link *
 bpf_program__attach_kprobe_opts(struct bpf_program *prog,
                                const char *func_name,
-                               struct bpf_program_attach_kprobe_opts *opts)
+                               struct bpf_kprobe_opts *opts)
 {
        char errmsg[STRERR_BUFSIZE];
        struct bpf_link *link;
+       unsigned long offset;
+       bool retprobe;
        int pfd, err;
 
-       pfd = perf_event_open_probe(false /* uprobe */, opts->retprobe, func_name,
-                                   opts->offset, -1 /* pid */);
+       if (!OPTS_VALID(opts, bpf_kprobe_opts))
+               return libbpf_err_ptr(-EINVAL);
+
+       retprobe = OPTS_GET(opts, retprobe, false);
+       offset = OPTS_GET(opts, offset, 0);
+
+       pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
+                                   offset, -1 /* pid */);
        if (pfd < 0) {
                pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
-                       prog->name, opts->retprobe ? "kretprobe" : "kprobe", func_name,
+                       prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
                        libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
                return libbpf_err_ptr(pfd);
        }
@@ -10393,7 +10396,7 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog,
        if (err) {
                close(pfd);
                pr_warn("prog '%s': failed to attach to %s '%s': %s\n",
-                       prog->name, opts->retprobe ? "kretprobe" : "kprobe", func_name,
+                       prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
                        libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
                return libbpf_err_ptr(err);
        }
@@ -10404,9 +10407,9 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
                                            bool retprobe,
                                            const char *func_name)
 {
-       struct bpf_program_attach_kprobe_opts opts = {
+       DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts,
                .retprobe = retprobe,
-       };
+       );
 
        return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
 }
@@ -10414,7 +10417,7 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
 static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
                                      struct bpf_program *prog)
 {
-       struct bpf_program_attach_kprobe_opts opts;
+       DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
        unsigned long offset = 0;
        struct bpf_link *link;
        const char *func_name;

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6b08c10..9ec6b72 100644 (file)
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -104,6 +104,17 @@ 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);
@@ -250,6 +261,10 @@ 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);
+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);

diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 5bfc107..887d372 100644 (file)
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -372,6 +372,7 @@ LIBBPF_0.5.0 {
        global:
                bpf_map__initial_value;
                bpf_map_lookup_and_delete_elem_flags;
+               bpf_program__attach_kprobe_opts;
                bpf_object__gen_loader;
                btf_dump__dump_type_data;
                libbpf_set_strict_mode;