On Wed, Aug 08, 2018 at 06:25:19PM -0700, Yonghong Song wrote:
> In function map_seq_next() of kernel/bpf/inode.c,
> the first key will be the "0" regardless of the map type.
> This works for array. But for hash type, if it happens
> key "0" is in the map, the bpffs map show will miss
> some items if the key "0" is not the first element of
> the first bucket.
>
> This patch fixed the issue by guaranteeing to get
> the first element, if the seq_show is just started,
> by passing NULL pointer key to map_get_next_key() callback.
> This way, no missing elements will occur for
> bpffs hash table show even if key "0" is in the map.
>
> Fixes: a26ca7c982cb5 ("bpf: btf: Add pretty print support to the basic
> arraymap")
> Signed-off-by: Yonghong Song <y...@fb.com>
Acked-by: Alexei Starovoitov <a...@kernel.org>
