From: Jason Wang <jasowang@redhat.com> To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>, netdev@vger.kernel.org Cc: "Michael S. Tsirkin" <mst@redhat.com>, "David S. Miller" <davem@davemloft.net>, "Jakub Kicinski" <kuba@kernel.org>, virtualization@lists.linux-foundation.org, "Corentin Noël" <corentin.noel@collabora.com> Subject: Re: [PATCH net] virtio-net: fix for skb_over_panic inside big mode Date: Fri, 4 Jun 2021 10:28:41 +0800 [thread overview] Message-ID: <231466df-adc1-79a9-6950-77c88e2783c2@redhat.com> (raw) In-Reply-To: <20210603170901.66504-1-xuanzhuo@linux.alibaba.com> 在 2021/6/4 上午1:09, Xuan Zhuo 写道: > In virtio-net's large packet mode, there is a hole in the space behind > buf. before the buf actually or behind the vnet header? > > hdr_padded_len - hdr_len > > We must take this into account when calculating tailroom. > > [ 44.544385] skb_put.cold (net/core/skbuff.c:5254 (discriminator 1) net/core/skbuff.c:5252 (discriminator 1)) > [ 44.544864] page_to_skb (drivers/net/virtio_net.c:485) [ 44.545361] receive_buf (drivers/net/virtio_net.c:849 drivers/net/virtio_net.c:1131) > [ 44.545870] ? netif_receive_skb_list_internal (net/core/dev.c:5714) > [ 44.546628] ? dev_gro_receive (net/core/dev.c:6103) > [ 44.547135] ? napi_complete_done (./include/linux/list.h:35 net/core/dev.c:5867 net/core/dev.c:5862 net/core/dev.c:6565) > [ 44.547672] virtnet_poll (drivers/net/virtio_net.c:1427 drivers/net/virtio_net.c:1525) > [ 44.548251] __napi_poll (net/core/dev.c:6985) > [ 44.548744] net_rx_action (net/core/dev.c:7054 net/core/dev.c:7139) > [ 44.549264] __do_softirq (./arch/x86/include/asm/jump_label.h:19 ./include/linux/jump_label.h:200 ./include/trace/events/irq.h:142 kernel/softirq.c:560) > [ 44.549762] irq_exit_rcu (kernel/softirq.c:433 kernel/softirq.c:637 kernel/softirq.c:649) > [ 44.551384] common_interrupt (arch/x86/kernel/irq.c:240 (discriminator 13)) > [ 44.551991] ? asm_common_interrupt (./arch/x86/include/asm/idtentry.h:638) > [ 44.552654] asm_common_interrupt (./arch/x86/include/asm/idtentry.h:638) > > Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > Reported-by: Corentin Noël <corentin.noel@collabora.com> > Tested-by: Corentin Noël <corentin.noel@collabora.com> > --- > drivers/net/virtio_net.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index fa407eb8b457..78a01c71a17c 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -406,7 +406,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > * add_recvbuf_mergeable() + get_mergeable_buf_len() > */ > truesize = headroom ? PAGE_SIZE : truesize; > - tailroom = truesize - len - headroom; > + tailroom = truesize - len - headroom - (hdr_padded_len - hdr_len); The patch looks correct and I saw it has been merged. But I prefer to do that in receive_big() instead of here. Thanks > buf = p - headroom; > > len -= hdr_len;
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com> To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>, netdev@vger.kernel.org Cc: "Jakub Kicinski" <kuba@kernel.org>, virtualization@lists.linux-foundation.org, "David S. Miller" <davem@davemloft.net>, "Corentin Noël" <corentin.noel@collabora.com>, "Michael S. Tsirkin" <mst@redhat.com> Subject: Re: [PATCH net] virtio-net: fix for skb_over_panic inside big mode Date: Fri, 4 Jun 2021 10:28:41 +0800 [thread overview] Message-ID: <231466df-adc1-79a9-6950-77c88e2783c2@redhat.com> (raw) In-Reply-To: <20210603170901.66504-1-xuanzhuo@linux.alibaba.com> 在 2021/6/4 上午1:09, Xuan Zhuo 写道: > In virtio-net's large packet mode, there is a hole in the space behind > buf. before the buf actually or behind the vnet header? > > hdr_padded_len - hdr_len > > We must take this into account when calculating tailroom. > > [ 44.544385] skb_put.cold (net/core/skbuff.c:5254 (discriminator 1) net/core/skbuff.c:5252 (discriminator 1)) > [ 44.544864] page_to_skb (drivers/net/virtio_net.c:485) [ 44.545361] receive_buf (drivers/net/virtio_net.c:849 drivers/net/virtio_net.c:1131) > [ 44.545870] ? netif_receive_skb_list_internal (net/core/dev.c:5714) > [ 44.546628] ? dev_gro_receive (net/core/dev.c:6103) > [ 44.547135] ? napi_complete_done (./include/linux/list.h:35 net/core/dev.c:5867 net/core/dev.c:5862 net/core/dev.c:6565) > [ 44.547672] virtnet_poll (drivers/net/virtio_net.c:1427 drivers/net/virtio_net.c:1525) > [ 44.548251] __napi_poll (net/core/dev.c:6985) > [ 44.548744] net_rx_action (net/core/dev.c:7054 net/core/dev.c:7139) > [ 44.549264] __do_softirq (./arch/x86/include/asm/jump_label.h:19 ./include/linux/jump_label.h:200 ./include/trace/events/irq.h:142 kernel/softirq.c:560) > [ 44.549762] irq_exit_rcu (kernel/softirq.c:433 kernel/softirq.c:637 kernel/softirq.c:649) > [ 44.551384] common_interrupt (arch/x86/kernel/irq.c:240 (discriminator 13)) > [ 44.551991] ? asm_common_interrupt (./arch/x86/include/asm/idtentry.h:638) > [ 44.552654] asm_common_interrupt (./arch/x86/include/asm/idtentry.h:638) > > Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > Reported-by: Corentin Noël <corentin.noel@collabora.com> > Tested-by: Corentin Noël <corentin.noel@collabora.com> > --- > drivers/net/virtio_net.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index fa407eb8b457..78a01c71a17c 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -406,7 +406,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > * add_recvbuf_mergeable() + get_mergeable_buf_len() > */ > truesize = headroom ? PAGE_SIZE : truesize; > - tailroom = truesize - len - headroom; > + tailroom = truesize - len - headroom - (hdr_padded_len - hdr_len); The patch looks correct and I saw it has been merged. But I prefer to do that in receive_big() instead of here. Thanks > buf = p - headroom; > > len -= hdr_len; _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-06-04 2:28 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-03 17:09 [PATCH net] virtio-net: fix for skb_over_panic inside big mode Xuan Zhuo 2021-06-03 17:09 ` Xuan Zhuo 2021-06-03 22:30 ` patchwork-bot+netdevbpf 2021-06-04 2:28 ` Jason Wang [this message] 2021-06-04 2:28 ` Jason Wang 2021-06-04 2:30 ` Xuan Zhuo 2021-06-04 3:00 ` Jason Wang 2021-06-04 3:00 ` Jason Wang 2021-06-04 3:05 ` Xuan Zhuo 2021-06-04 6:00 ` Jason Wang 2021-06-04 6:00 ` Jason Wang 2021-10-09 9:17 Michael S. Tsirkin 2021-10-09 9:17 ` Michael S. Tsirkin 2021-10-09 9:29 ` Xuan Zhuo 2021-10-11 2:04 ` Jason Wang 2021-10-11 2:04 ` Jason Wang
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