From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752522AbeEVDhr (ORCPT ); Mon, 21 May 2018 23:37:47 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59228 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751719AbeEVDho (ORCPT ); Mon, 21 May 2018 23:37:44 -0400 Subject: Re: [PATCH net 4/4] virito-net: fix leaking page for gso packet during mergeable XDP To: "Michael S. Tsirkin" Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, John Fastabend References: <1526891706-18516-1-git-send-email-jasowang@redhat.com> <1526891706-18516-5-git-send-email-jasowang@redhat.com> <20180521175919-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: Date: Tue, 22 May 2018 11:37:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180521175919-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018年05月21日 23:01, Michael S. Tsirkin wrote: > On Mon, May 21, 2018 at 04:35:06PM +0800, Jason Wang wrote: >> We need to drop refcnt to xdp_page if we see a gso packet. Otherwise >> it will be leaked. Fixing this by moving the check of gso packet above >> the linearizing logic. >> >> Cc: John Fastabend >> Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers") >> Signed-off-by: Jason Wang > typo in subject Let me fix it in V2. >> --- >> drivers/net/virtio_net.c | 16 ++++++++-------- >> 1 file changed, 8 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 165a922..f8db809 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -707,6 +707,14 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, >> void *data; >> u32 act; >> >> + /* Transient failure which in theory could occur if >> + * in-flight packets from before XDP was enabled reach >> + * the receive path after XDP is loaded. In practice I >> + * was not able to create this condition. > BTW we should probably drop the last sentence. It says in theory, should be enough. Ok. Thanks >> + */ >> + if (unlikely(hdr->hdr.gso_type)) >> + goto err_xdp; >> + >> /* This happens when rx buffer size is underestimated >> * or headroom is not enough because of the buffer >> * was refilled before XDP is set. This should only >> @@ -728,14 +736,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, >> xdp_page = page; >> } >> >> - /* Transient failure which in theory could occur if >> - * in-flight packets from before XDP was enabled reach >> - * the receive path after XDP is loaded. In practice I >> - * was not able to create this condition. >> - */ >> - if (unlikely(hdr->hdr.gso_type)) >> - goto err_xdp; >> - >> /* Allow consuming headroom but reserve enough space to push >> * the descriptor on if we get an XDP_TX return code. >> */ >> -- >> 2.7.4