On Thu, Aug 20, 2020 at 3:50 PM Yonghong Song <yhs@xxxxxx> wrote:
>
> 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@xxxxxx>
> ---
> include/linux/bpf.h | 4 ++++
> kernel/bpf/map_iter.c | 15 +++++++++++++++
> net/core/bpf_sk_storage.c | 2 ++
> 3 files changed, 21 insertions(+)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 529e9b183eeb..30c144af894a 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1256,6 +1256,10 @@ int bpf_iter_new_fd(struct bpf_link *link);
> bool bpf_link_is_iter(struct bpf_link *link);
> struct bpf_prog *bpf_iter_get_info(struct bpf_iter_meta *meta, bool in_stop);
> int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx);
> +void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
> + struct seq_file *seq);
> +int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
> + struct bpf_link_info *info);
>
> int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
> int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
> diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
> index af86048e5afd..714e74556aa2 100644
> --- a/kernel/bpf/map_iter.c
> +++ b/kernel/bpf/map_iter.c
> @@ -149,6 +149,19 @@ static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
> bpf_map_put_with_uref(aux->map);
> }
>
> +void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
> + struct seq_file *seq)
> +{
> + seq_printf(seq, "map_id:\t\t%u\n", aux->map->id);
nit: I think it's a bad idea to have two tabs here to align everything
visually, might make parsing unnecessarily harder
> +}
> +
> +int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
> + struct bpf_link_info *info)
> +{
> + info->iter.map.map_id = aux->map->id;
> + return 0;
> +}
> +
> DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
> struct bpf_map *map, void *key, void *value)
>
> @@ -156,6 +169,8 @@ static const struct bpf_iter_reg bpf_map_elem_reg_info = {
> .target = "bpf_map_elem",
> .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_map_elem, key),
> diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
> index b988f48153a4..281200dc0a01 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),
> --
> 2.24.1
>
