On Tue, Aug 16, 2022 at 01:12:11PM -0700, Stanislav Fomichev wrote:
> Apparently, only a small subset of cgroup hooks actually falls
> back to cgroup_base_func_proto. This leads to unexpected result
> where not all cgroup helpers have bpf_{g,s}et_retval.
>
> It's getting harder and harder to manage which helpers are exported
> to which hooks. We now have the following call chains:
>
> - cg_skb_func_proto
> - sk_filter_func_proto
> - bpf_sk_base_func_proto
> - bpf_base_func_proto
Could you explain how bpf_set_retval() will work with cgroup prog that
is not syscall and can return flags in the higher bit (e.g. cg_skb egress).
It will be a useful doc to add to the uapi bpf.h for
the bpf_set_retval() helper.
