Re: [RFC PATCH bpf-next 1/2] bpf, x64: Fix tailcall infinite loop bug

[Alexei Starovoitov]

On Thu, Aug 17, 2023 at 7:10 PM Leon Hwang <hffilwlqm@xxxxxxxxx> wrote:
>
>
>
> On 18/8/23 06:31, Alexei Starovoitov wrote:
> > On Mon, Aug 14, 2023 at 09:41:46PM +0800, Leon Hwang wrote:
> >> @@ -1147,6 +1152,7 @@ struct bpf_attach_target_info {
> >>      struct module *tgt_mod;
> >>      const char *tgt_name;
> >>      const struct btf_type *tgt_type;
> >> +    bool tail_call_ctx;
> >
> > Instead of extra flag here can you check tgt_prog->aux->tail_call_reachable in check_attach_btf_id()
> > and set tr->flags there?
>
> Should we check tgt_prog->aux->func[subprog]->is_func? Or, tgt_prog->aux->tail_call_reachable
> is enough?

Please let the thread continue to a logical conclusion before resending
new version. Will reply there.