iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

libbpf: improve old BPF skeleton handling for map auto-attach

Browse Source 
Improve how we handle old BPF skeletons when it comes to BPF map
auto-attachment. Emit one warn-level message per each struct_ops map
that could have been auto-attached, if user provided recent enough BPF
skeleton version. Don't spam log if there are no relevant struct_ops
maps, though.

This should help users realize that they probably need to regenerate BPF
skeleton header with more recent bpftool/libbpf-cargo (or whatever other
means of BPF skeleton generation).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240708204540.4188946-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko 2024-07-08 13:45:40 -07:00 committed by Alexei Starovoitov
parent 99fb953188
commit a459f4bb27
1 changed files with 14 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
tools/lib/bpf/libbpf.c
View File

@ -13967,32 +13967,34 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
*/
}
/* Skeleton is created with earlier version of bpftool
* which does not support auto-attachment
*/
if (s->map_skel_sz < sizeof(struct bpf_map_skeleton))
return 0;
for (i = 0; i < s->map_cnt; i++) {
struct bpf_map_skeleton *map_skel = (void *)s->maps + i * s->map_skel_sz;
struct bpf_map *map = *map_skel->map;
struct bpf_link **link = map_skel->link;
struct bpf_link **link;
if (!map->autocreate || !map->autoattach)
continue;
if (*link)
continue;
/* only struct_ops maps can be attached */
if (!bpf_map__is_struct_ops(map))
continue;
*link = bpf_map__attach_struct_ops(map);
/* skeleton is created with earlier version of bpftool, notify user */
if (s->map_skel_sz < offsetofend(struct bpf_map_skeleton, link)) {
pr_warn("map '%s': BPF skeleton version is old, skipping map auto-attachment...\n",
bpf_map__name(map));
continue;
}
link = map_skel->link;
if (*link)
continue;
*link = bpf_map__attach_struct_ops(map);
if (!*link) {
err = -errno;
pr_warn("map '%s': failed to auto-attach: %d\n",
bpf_map__name(map), err);
pr_warn("map '%s': failed to auto-attach: %d\n", bpf_map__name(map), err);
return libbpf_err(err);
}
}