diff mbox series

[bpf-next,v2,4/5] libbpf: add split BTF support for btf__load_from_kernel_by_id()

Message ID 20210721153808.6902-5-quentin@isovalent.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series libbpf: rename btf__get_from_id() and btf__load() APIs, support split BTF | expand

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Commit Message

Quentin Monnet July 21, 2021, 3:38 p.m. UTC
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>
Acked-by: John Fastabend <john.fastabend@gmail.com>
---
 tools/lib/bpf/btf.c      | 9 +++++++--
 tools/lib/bpf/btf.h      | 2 ++
 tools/lib/bpf/libbpf.map | 1 +
 3 files changed, 10 insertions(+), 2 deletions(-)

Comments

Andrii Nakryiko July 23, 2021, 12:49 a.m. UTC | #1
On Wed, Jul 21, 2021 at 8:38 AM Quentin Monnet <quentin@isovalent.com> wrote:
>
> 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>
> Acked-by: John Fastabend <john.fastabend@gmail.com>
> ---
>  tools/lib/bpf/btf.c      | 9 +++++++--
>  tools/lib/bpf/btf.h      | 2 ++
>  tools/lib/bpf/libbpf.map | 1 +
>  3 files changed, 10 insertions(+), 2 deletions(-)
>

[...]

> diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
> index 3db9446bc133..c9407d57d096 100644
> --- a/tools/lib/bpf/btf.h
> +++ b/tools/lib/bpf/btf.h
> @@ -69,6 +69,8 @@ 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 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);

nit: please keep it on a single line, it's not that long

>  LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
>                                     __u32 expected_key_size,
>                                     __u32 expected_value_size,
> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> index ca8cc7a7faad..eecf77227aeb 100644
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -374,6 +374,7 @@ LIBBPF_0.5.0 {
>                 bpf_map_lookup_and_delete_elem_flags;
>                 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;
> --
> 2.30.2
>
diff mbox series

Patch

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 6654bdee7ad7..38a901e3a483 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -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 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;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 3db9446bc133..c9407d57d096 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -69,6 +69,8 @@  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 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_map_kv_tids(const struct btf *btf, const char *map_name,
 				    __u32 expected_key_size,
 				    __u32 expected_value_size,
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index ca8cc7a7faad..eecf77227aeb 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -374,6 +374,7 @@  LIBBPF_0.5.0 {
 		bpf_map_lookup_and_delete_elem_flags;
 		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;