libbpf: Clean up deprecated and legacy aliases

Remove three missed deprecated APIs that were aliased to new APIs:
bpf_object__unload, bpf_prog_attach_xattr and btf__load.

Also move legacy API libbpf_find_kernel_btf (aliased to
btf__load_vmlinux_btf) into libbpf_legacy.h.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20220816001929.369487-4-andrii@kernel.org

tools/lib/bpf/bpf.c

@@ -641,11 +641,6 @@ int bpf_prog_attach_opts(int prog_fd, int target_fd,
 	return libbpf_err_errno(ret);
 }
 
-__attribute__((alias("bpf_prog_attach_opts")))
-int bpf_prog_attach_xattr(int prog_fd, int target_fd,
-			  enum bpf_attach_type type,
-			  const struct bpf_prog_attach_opts *opts);
-
 int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
 {
 	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);

tools/lib/bpf/btf.c

@@ -1225,8 +1225,6 @@ int btf__load_into_kernel(struct btf *btf)
 	return btf_load_into_kernel(btf, NULL, 0, 0);
 }
 
-int btf__load(struct btf *) __attribute__((alias("btf__load_into_kernel")));
-
 int btf__fd(const struct btf *btf)
 {
 	return btf->fd;

tools/lib/bpf/btf.h

@@ -116,7 +116,6 @@ LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_b
 
 LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
 LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
-LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
 
 LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
 LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);

tools/lib/bpf/libbpf.c

@@ -7263,8 +7263,6 @@ static int bpf_object_unload(struct bpf_object *obj)
 	return 0;
 }
 
-int bpf_object__unload(struct bpf_object *obj) __attribute__((alias("bpf_object_unload")));
-
 static int bpf_object__sanitize_maps(struct bpf_object *obj)
 {
 	struct bpf_map *m;

tools/lib/bpf/libbpf_legacy.h

@@ -125,6 +125,8 @@ struct bpf_map;
 struct btf;
 struct btf_ext;
 
+LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
+
 LIBBPF_API enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
 LIBBPF_API enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog);
 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);