From: Quentin Monnet <quentin@isovalent.com>
Date: Thu, 29 Jul 2021 17:20:27 +0100
Subject: libbpf: Add split BTF support for btf__load_from_kernel_by_id()
Patch-mainline: v5.15-rc1
Git-commit: 61fc51b1d3e5915e356f2c0b67cd3bb13b640413
References: jsc#PED-1377
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
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/lib/bpf/btf.c | 9 +++++++--
tools/lib/bpf/btf.h | 1 +
tools/lib/bpf/libbpf.map | 1 +
3 files changed, 9 insertions(+), 2 deletions(-)
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1382,7 +1382,7 @@ 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;
@@ -1391,12 +1391,17 @@ struct btf *btf__load_from_kernel_by_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;
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -45,6 +45,7 @@ LIBBPF_API struct btf *btf__parse_raw(co
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);
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -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;