[PATCH bpf-next] libbpf: add getters for BTF.ext func and line info

[Mykyta Yatsenko <mykyta.yatsenko5@xxxxxxxxx>]

From: Mykyta Yatsenko <yatsenko@xxxxxxxx>

Introducing new libbpf API getters for BTF.ext func and line info,
namely:
  bpf_program__func_info
  bpf_program__func_info_cnt
  bpf_program__func_info_rec_size
  bpf_program__line_info
  bpf_program__line_info_cnt
  bpf_program__line_info_rec_size

This change enables scenarios, when user needs to load bpf_program
directly using `bpf_prog_load`, instead of higher-level
`bpf_object__load`. Line and func info are required for checking BTF
info in verifier; verification may fail without these fields if, for
example, program calls `bpf_obj_new`.

Signed-off-by: Mykyta Yatsenko <yatsenko@xxxxxxxx>
---
 tools/lib/bpf/libbpf.c   | 30 ++++++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h   |  8 ++++++++
 tools/lib/bpf/libbpf.map |  6 ++++++
 3 files changed, 44 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6b85060f07b3..bc15526ed84c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9455,6 +9455,36 @@ int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log
 	return 0;
 }
 
+void *bpf_program__func_info(struct bpf_program *prog)
+{
+	return prog->func_info;
+}
+
+__u32 bpf_program__func_info_cnt(struct bpf_program *prog)
+{
+	return prog->func_info_cnt;
+}
+
+__u32 bpf_program__func_info_rec_size(struct bpf_program *prog)
+{
+	return prog->func_info_rec_size;
+}
+
+void *bpf_program__line_info(struct bpf_program *prog)
+{
+	return prog->line_info;
+}
+
+__u32 bpf_program__line_info_cnt(struct bpf_program *prog)
+{
+	return prog->line_info_cnt;
+}
+
+__u32 bpf_program__line_info_rec_size(struct bpf_program *prog)
+{
+	return prog->line_info_rec_size;
+}
+
 #define SEC_DEF(sec_pfx, ptype, atype, flags, ...) {			    \
 	.sec = (char *)sec_pfx,						    \
 	.prog_type = BPF_PROG_TYPE_##ptype,				    \
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index e0605403f977..29a5fd7f51f0 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -940,6 +940,14 @@ LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_le
 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
 
+LIBBPF_API void *bpf_program__func_info(struct bpf_program *prog);
+LIBBPF_API __u32 bpf_program__func_info_cnt(struct bpf_program *prog);
+LIBBPF_API __u32 bpf_program__func_info_rec_size(struct bpf_program *prog);
+
+LIBBPF_API void *bpf_program__line_info(struct bpf_program *prog);
+LIBBPF_API __u32 bpf_program__line_info_cnt(struct bpf_program *prog);
+LIBBPF_API __u32 bpf_program__line_info_rec_size(struct bpf_program *prog);
+
 /**
  * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
  * for supported BPF program types:
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index d8b71f22f197..a5d83189c084 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -437,6 +437,12 @@ LIBBPF_1.6.0 {
 		bpf_linker__add_fd;
 		bpf_linker__new_fd;
 		bpf_object__prepare;
+		bpf_program__func_info;
+		bpf_program__func_info_cnt;
+		bpf_program__func_info_rec_size;
+		bpf_program__line_info;
+		bpf_program__line_info_cnt;
+		bpf_program__line_info_rec_size;
 		btf__add_decl_attr;
 		btf__add_type_attr;
 } LIBBPF_1.5.0;
-- 
2.48.1