Received-SPF: pass (google.com: domain of linux-kernel+bounces-96947-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Date: Fri, 08 Mar 2024 06:43:31 -0500
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Juntong Deng <juntong.deng@outlook.com>, 
 willemdebruijn.kernel@gmail.com, 
 davem@davemloft.net, 
 edumazet@google.com, 
 kuba@kernel.org, 
 pabeni@redhat.com
Cc: netdev@vger.kernel.org, 
 linux-kernel@vger.kernel.org
Message-ID: <65eaf9e336d07_133b25294db@willemb.c.googlers.com.notmuch>
In-Reply-To: <AM6PR03MB5848595A20BB5D958C2D9DE299272@AM6PR03MB5848.eurprd03.prod.outlook.com>
References: <AM6PR03MB5848595A20BB5D958C2D9DE299272@AM6PR03MB5848.eurprd03.prod.outlook.com>
Subject: Re: [PATCH net-next] net/packet: Add getsockopt support for
 PACKET_COPY_THRESH
Precedence: bulk
Mime-Version: 1.0
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: 7bit

Juntong Deng wrote:
> Currently getsockopt does not support PACKET_COPY_THRESH,
> and we are unable to get the value of PACKET_COPY_THRESH
> socket option through getsockopt.
> 
> This patch adds getsockopt support for PACKET_COPY_THRESH.
> 
> Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
> ---
>  net/packet/af_packet.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
> index 0db31ca4982d..65042edd1a97 100644
> --- a/net/packet/af_packet.c
> +++ b/net/packet/af_packet.c
> @@ -4090,6 +4090,9 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
>  	case PACKET_VNET_HDR_SZ:
>  		val = READ_ONCE(po->vnet_hdr_sz);
>  		break;
> +	case PACKET_COPY_THRESH:
> +		val = pkt_sk(sk)->copy_thresh;
> +		break;

This is probably a good opportunity to use READ_ONCE/WRITE_ONCE for
this variable that can be modified and read concurrently.

Alternatively I can fix up all three locations in a follow-on patch.

No concerns with adding the getsockopt itself.

>  	case PACKET_VERSION:
>  		val = po->tp_version;
>  		break;
> -- 
> 2.39.2
>