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Date:   Wed, 16 Mar 2022 21:56:06 -0600
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Subject: Re: [PATCH net-next v3 2/3] net: icmp: introduce
 __ping_queue_rcv_skb() to report drop reasons
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To:     menglong8.dong@gmail.com, kuba@kernel.org, pabeni@redhat.com
Cc:     rostedt@goodmis.org, mingo@redhat.com, xeb@mail.ru,
        davem@davemloft.net, yoshfuji@linux-ipv6.org,
        imagedong@tencent.com, edumazet@google.com, kafai@fb.com,
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        flyingpeng@tencent.com, mengensun@tencent.com,
        dongli.zhang@oracle.com, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, benbjiang@tencent.com
References: <20220316063148.700769-1-imagedong@tencent.com>
 <20220316063148.700769-3-imagedong@tencent.com>
From:   David Ahern <dsahern@kernel.org>
In-Reply-To: <20220316063148.700769-3-imagedong@tencent.com>
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On 3/16/22 12:31 AM, menglong8.dong@gmail.com wrote:
> diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
> index 3ee947557b88..9a1ea6c263f8 100644
> --- a/net/ipv4/ping.c
> +++ b/net/ipv4/ping.c
> @@ -934,16 +934,24 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
>  }
>  EXPORT_SYMBOL_GPL(ping_recvmsg);
>  
> -int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
> +static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
> +						 struct sk_buff *skb)
>  {
> +	enum skb_drop_reason reason;
> +
>  	pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
>  		 inet_sk(sk), inet_sk(sk)->inet_num, skb);
> -	if (sock_queue_rcv_skb(sk, skb) < 0) {
> -		kfree_skb(skb);
> +	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
> +		kfree_skb_reason(skb, reason);
>  		pr_debug("ping_queue_rcv_skb -> failed\n");
> -		return -1;
> +		return reason;
>  	}
> -	return 0;
> +	return SKB_NOT_DROPPED_YET;
> +}
> +
> +int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
> +{
> +	return __ping_queue_rcv_skb(sk, skb) ?: -1;
>  }
>  EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
>  

This is a generic proto callback and you are now changing its return
code in a way that seems to conflict with existing semantics