Commit 6cc93e2f authored by Quentin Monnet's avatar Quentin Monnet Committed by Andrii Nakryiko
Browse files

libbpf: Rename btf__get_from_id() as btf__load_from_kernel_by_id() 

Rename function btf__get_from_id() as btf__load_from_kernel_by_id() to
better indicate what the function does. Change the new function so that,
instead of requiring a pointer to the pointer to update and returning
with an error code, it takes a single argument (the id of the BTF
object) and returns the corresponding pointer. This is more in line with
the existing constructors.

The other tools calling the (soon-to-be) deprecated btf__get_from_id()
function will be updated in a future commit.

References:

- https://github.com/libbpf/libbpf/issues/278
- https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis



Signed-off-by: default avatarQuentin Monnet <quentin@isovalent.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210729162028.29512-4-quentin@isovalent.com
parent 3c7e5859

tools/lib/bpf/btf.c

+17 −8
Original line number Diff line number Diff line
@@ -1383,21 +1383,30 @@ struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf) 
	return btf;

}



int btf__get_from_id(__u32 id, struct btf **btf)

struct btf *btf__load_from_kernel_by_id(__u32 id)

{

	struct btf *res;

	int err, btf_fd;

	struct btf *btf;

	int btf_fd;



	*btf = NULL;

	btf_fd = bpf_btf_get_fd_by_id(id);

	if (btf_fd < 0)

		return libbpf_err(-errno);



	res = btf_get_from_fd(btf_fd, NULL);

	err = libbpf_get_error(res);

		return libbpf_err_ptr(-errno);



	btf = btf_get_from_fd(btf_fd, NULL);

	close(btf_fd);



	return libbpf_ptr(btf);

}



int btf__get_from_id(__u32 id, struct btf **btf)

{

	struct btf *res;

	int err;



	*btf = NULL;

	res = btf__load_from_kernel_by_id(id);

	err = libbpf_get_error(res);



	if (err)

		return libbpf_err(err);

tools/lib/bpf/btf.h

+3 −1
Original line number Diff line number Diff line
@@ -44,6 +44,9 @@ LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_b 
LIBBPF_API struct btf *btf__parse_raw(const char *path);

LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);



LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);

LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);



LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);

LIBBPF_API int btf__load(struct btf *btf);

LIBBPF_API int btf__load_into_kernel(struct btf *btf);
@@ -67,7 +70,6 @@ LIBBPF_API void btf__set_fd(struct btf *btf, int fd); 
LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);

LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);

LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);

LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);

LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,

				    __u32 expected_key_size,

				    __u32 expected_value_size,

tools/lib/bpf/libbpf.c

+3 −2
Original line number Diff line number Diff line
@@ -8316,7 +8316,7 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) 
{

	struct bpf_prog_info_linear *info_linear;

	struct bpf_prog_info *info;

	struct btf *btf = NULL;

	struct btf *btf;

	int err;



	info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
@@ -8333,7 +8333,8 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) 
		pr_warn("The target program doesn't have BTF\n");

		goto out;

	}

	if (btf__get_from_id(info->btf_id, &btf)) {

	btf = btf__load_from_kernel_by_id(info->btf_id);

	if (libbpf_get_error(btf)) {

		pr_warn("Failed to get BTF of the program\n");

		goto out;

	}

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -375,6 +375,7 @@ LIBBPF_0.5.0 { 
		bpf_map_lookup_and_delete_elem_flags;

		bpf_program__attach_kprobe_opts;

		bpf_object__gen_loader;

		btf__load_from_kernel_by_id;

		btf__load_into_kernel;

		btf_dump__dump_type_data;

		libbpf_set_strict_mode;