Re: [PATCH bpf v5 1/3] bpf: fix wrong copied_seq calculation

From: Jakub Kicinski
Date: Mon Jan 13 2025 - 19:04:23 EST


On Thu, 9 Jan 2025 17:43:59 +0800 Jiayuan Chen wrote:
> However, for programs where both stream_parser and stream_verdict are
> active(strparser purpose), tcp_read_sock() was used instead of
> tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock)
> tcp_read_sock() now still update 'sk->copied_seq', leading to duplicated
> updates.

To state the obvious feels like the abstraction between TCP and psock
has broken down pretty severely at this stage. You're modifying TCP
and straight up calling TCP functions from skmsg.c :(

> +int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc,
> + sk_read_actor_t recv_actor, u32 noack,
> + u32 *copied_seq)
> +{
> + return __tcp_read_sock(sk, desc, recv_actor,
> + noack, copied_seq);
> +}
> +EXPORT_SYMBOL(tcp_read_sock_noack);

Pretty sure you don't have to export this. skmsg can't be a module.