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 73788dd22f
commit 512b472d97
3 changed files with 9 additions and 2 deletions

View File

@@ -1383,7 +1383,7 @@ exit_free:
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;