Commit 9c6660d0 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

libbpf: extract BTF loading logic 



As a preparation for adding BTF-based BPF map loading, extract .BTF and
.BTF.ext loading logic.

Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent d7fe74f9

tools/lib/bpf/libbpf.c

+55 −38
Original line number Diff line number Diff line
@@ -1078,6 +1078,58 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj) 
	}

}



static int bpf_object__load_btf(struct bpf_object *obj,

				Elf_Data *btf_data,

				Elf_Data *btf_ext_data)

{

	int err = 0;



	if (btf_data) {

		obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);

		if (IS_ERR(obj->btf)) {

			pr_warning("Error loading ELF section %s: %d.\n",

				   BTF_ELF_SEC, err);

			goto out;

		}

		err = btf__finalize_data(obj, obj->btf);

		if (err) {

			pr_warning("Error finalizing %s: %d.\n",

				   BTF_ELF_SEC, err);

			goto out;

		}

		bpf_object__sanitize_btf(obj);

		err = btf__load(obj->btf);

		if (err) {

			pr_warning("Error loading %s into kernel: %d.\n",

				   BTF_ELF_SEC, err);

			goto out;

		}

	}

	if (btf_ext_data) {

		if (!obj->btf) {

			pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",

				 BTF_EXT_ELF_SEC, BTF_ELF_SEC);

			goto out;

		}

		obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,

					    btf_ext_data->d_size);

		if (IS_ERR(obj->btf_ext)) {

			pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",

				   BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext));

			obj->btf_ext = NULL;

			goto out;

		}

		bpf_object__sanitize_btf_ext(obj);

	}

out:

	if (err || IS_ERR(obj->btf)) {

		if (!IS_ERR_OR_NULL(obj->btf))

			btf__free(obj->btf);

		obj->btf = NULL;

	}

	return 0;

}



static int bpf_object__elf_collect(struct bpf_object *obj, int flags)

{

	Elf *elf = obj->efile.elf;
@@ -1212,44 +1264,9 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) 
		pr_warning("Corrupted ELF file: index of strtab invalid\n");

		return -LIBBPF_ERRNO__FORMAT;

	}

	if (btf_data) {

		obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);

		if (IS_ERR(obj->btf)) {

			pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",

				   BTF_ELF_SEC, PTR_ERR(obj->btf));

			obj->btf = NULL;

		} else {

			err = btf__finalize_data(obj, obj->btf);

			if (!err) {

				bpf_object__sanitize_btf(obj);

				err = btf__load(obj->btf);

			}

			if (err) {

				pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",

					   BTF_ELF_SEC, err);

				btf__free(obj->btf);

				obj->btf = NULL;

				err = 0;

			}

		}

	}

	if (btf_ext_data) {

		if (!obj->btf) {

			pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",

				 BTF_EXT_ELF_SEC, BTF_ELF_SEC);

		} else {

			obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,

						    btf_ext_data->d_size);

			if (IS_ERR(obj->btf_ext)) {

				pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",

					   BTF_EXT_ELF_SEC,

					   PTR_ERR(obj->btf_ext));

				obj->btf_ext = NULL;

			} else {

				bpf_object__sanitize_btf_ext(obj);

			}

		}

	}

	err = bpf_object__load_btf(obj, btf_data, btf_ext_data);

	if (err)

		return err;

	if (bpf_object__has_maps(obj)) {

		err = bpf_object__init_maps(obj, flags);

		if (err)

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