Subject: Re: [PATCH v3,bpf-next] bpf: Don't redirect packets with invalid pkt_len

From: Jakub Kicinski <[email-masked]>
Date: Thu, 14 Jul 2022 21:30:25 -0700

On Fri, 15 Jul 2022 11:22:33 +0800 Zhengchao Shao wrote:
> +#ifdef CONFIG_DEBUG_NET
> +	if (unlikely(!skb->len)) {
> +		pr_err("%s\n", __func__);
> +		skb_dump(KERN_ERR, skb, false);
> +		WARN_ON_ONCE(1);
> +	}

Is there a reason to open code WARN_ONCE() like that?

#ifdef CONFIG_DEBUG_NET
	if (WARN_ONCE(!skb->len, "%s\n", __func__))
		skb_dump(KERN_ERR, skb, false);

or

	if (IS_ENABLED(CONFIG_DEBUG_NET) &&
	    WARN_ONCE(!skb->len, "%s\n", __func__))
		skb_dump(KERN_ERR, skb, false);