Re: [PATCH bpf-next v3 6/8] bpf: add documentation for eBPF helpers (42-50)

[Martin KaFai Lau <kafai@fb.com>]

On Tue, Apr 17, 2018 at 03:34:36PM +0100, Quentin Monnet wrote:
[...]
> @@ -965,6 +984,17 @@ union bpf_attr {
>   * 	Return
>   * 		0 on success, or a negative error in case of failure.
>   *
> + * int bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
> + * 	Description
> + * 		Check whether *skb* is a descendant of the cgroup2 held by
> + * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
> + * 	Return
> + * 		The return value depends on the result of the test, and can be:
> + *
> + * 		* 0, if the *skb* failed the cgroup2 descendant test.
> + * 		* 1, if the *skb* succeeded the cgroup2 descendant test.
> + * 		* A negative error code, if an error occurred.
> + *
[...]
> + * int bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
> + * 	Description
> + * 		Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
> + * 		it is possible to use a negative value for *delta*. This helper
> + * 		can be used to prepare the packet for pushing or popping
> + * 		headers.
> + *
> + * 		A call to this helper is susceptible to change data from the
> + * 		packet. Therefore, at load time, all checks on pointers
> + * 		previously done by the verifier are invalidated and must be
> + * 		performed again.
> + * 	Return
> + * 		0 on success, or a negative error in case of failure.
> + *
LGTM. Thanks!

Acked-by: Martin KaFai Lau <kafai@fb.com>