Commit 61fc51b1 authored by Quentin Monnet's avatar Quentin Monnet Committed by Andrii Nakryiko
Browse files

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: 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/20210729162028.29512-8-quentin@isovalent.com
parent 86f4b7f2

tools/lib/bpf/btf.c

+7 −2
Original line number Diff line number Diff line
@@ -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;

tools/lib/bpf/btf.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -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;