libbpf: Add split BTF support for btf__load_from_kernel_by_id()

Add a new API function btf__load_from_kernel_by_id_split(), which takes
a pointer to a base BTF object in order to support split BTF objects
when retrieving BTF information from the kernel.

Reference: https://github.com/libbpf/libbpf/issues/314

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210729162028.29512-8-quentin@isovalent.com
This commit is contained in:
Quentin Monnet 2021-07-29 17:20:27 +01:00 committed by Andrii Nakryiko
parent 86f4b7f257
commit 61fc51b1d3
3 changed files with 9 additions and 2 deletions

View file

@ -1383,7 +1383,7 @@ struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf)
return btf;
}
struct btf *btf__load_from_kernel_by_id(__u32 id)
struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf)
{
struct btf *btf;
int btf_fd;
@ -1392,12 +1392,17 @@ struct btf *btf__load_from_kernel_by_id(__u32 id)
if (btf_fd < 0)
return libbpf_err_ptr(-errno);
btf = btf_get_from_fd(btf_fd, NULL);
btf = btf_get_from_fd(btf_fd, base_btf);
close(btf_fd);
return libbpf_ptr(btf);
}
struct btf *btf__load_from_kernel_by_id(__u32 id)
{
return btf__load_from_kernel_by_id_split(id, NULL);
}
int btf__get_from_id(__u32 id, struct btf **btf)
{
struct btf *res;

View file

@ -45,6 +45,7 @@ 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 struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
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);

View file

@ -376,6 +376,7 @@ LIBBPF_0.5.0 {
bpf_program__attach_kprobe_opts;
bpf_object__gen_loader;
btf__load_from_kernel_by_id;
btf__load_from_kernel_by_id_split;
btf__load_into_kernel;
btf_dump__dump_type_data;
libbpf_set_strict_mode;