bpf: Implement link_query callbacks in map element iterators
For bpf_map_elem and bpf_sk_local_storage bpf iterators,
additional map_id should be shown for fdinfo and
userspace query. For example, the following is for
a bpf_map_elem iterator.
$ cat /proc/1753/fdinfo/9
pos: 0
flags: 02000000
mnt_id: 14
link_type: iter
link_id: 34
prog_tag: 104be6d3fe45e6aa
prog_id: 173
target_name: bpf_map_elem
map_id: 127
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200821184419.574240-1-yhs@fb.com
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index b988f48..281200d 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -1437,6 +1437,8 @@ static struct bpf_iter_reg bpf_sk_storage_map_reg_info = {
.target = "bpf_sk_storage_map",
.attach_target = bpf_iter_attach_map,
.detach_target = bpf_iter_detach_map,
+ .show_fdinfo = bpf_iter_map_show_fdinfo,
+ .fill_link_info = bpf_iter_map_fill_link_info,
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_sk_storage_map, sk),
