kernel/git/stable/linux.git/drivers/net/tun.c, branch linux-5.18.y

net: tun: avoid disabling NAPI twice

2022-07-07T15:54:58+00:00

commit ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5 upstream. Eric reports that syzbot made short work out of my speculative fix. Indeed when queue gets detached its tfile->tun remains, so we would try to stop NAPI twice with a detach(), close() sequence. Alternative fix would be to move tun_napi_disable() to tun_detach_all() and let the NAPI run after the queue has been detached. Fixes: a8fc8cb5692a ("net: tun: stop NAPI when detaching queues") Reported-by: syzbot Reported-by: Eric Dumazet Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220629181911.372047-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: tun: stop NAPI when detaching queues

2022-07-07T15:54:48+00:00

commit a8fc8cb5692aebb9c6f7afd4265366d25dcd1d01 upstream. While looking at a syzbot report I noticed the NAPI only gets disabled before it's deleted. I think that user can detach the queue before destroying the device and the NAPI will never be stopped. Fixes: 943170998b20 ("tun: enable NAPI for TUN/TAP driver") Acked-by: Petar Penkov Link: https://lore.kernel.org/r/20220623042105.2274812-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: tun: unlink NAPI from device on destruction

2022-07-07T15:54:48+00:00

commit 3b9bc84d311104906d2b4995a9a02d7b7ddab2db upstream. Syzbot found a race between tun file and device destruction. NAPIs live in struct tun_file which can get destroyed before the netdev so we have to del them explicitly. The current code is missing deleting the NAPI if the queue was detached first. Fixes: 943170998b20 ("tun: enable NAPI for TUN/TAP driver") Reported-by: syzbot+b75c138e9286ac742647@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20220623042039.2274708-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

tun: annotate access to queue->trans_start

2022-04-14T06:30:09+00:00

Commit 5337824f4dc4 ("net: annotate accesses to queue->trans_start") introduced a new helper, txq_trans_cond_update, to update queue->trans_start using WRITE_ONCE. One snippet in drivers/net/tun.c was missed, as it was introduced roughly at the same time. Fixes: 5337824f4dc4 ("net: annotate accesses to queue->trans_start") Cc: Eric Dumazet Signed-off-by: Antoine Tenart Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220412135852.466386-1-atenart@kernel.org Signed-off-by: Paolo Abeni

net: add per-cpu storage and net->core_stats

2022-03-12T07:17:24+00:00

Before adding yet another possibly contended atomic_long_t, it is time to add per-cpu storage for existing ones: dev->tx_dropped, dev->rx_dropped, and dev->rx_nohandler Because many devices do not have to increment such counters, allocate the per-cpu storage on demand, so that dev_get_stats() does not have to spend considerable time folding zero counters. Note that some drivers have abused these counters which were supposed to be only used by core networking stack. v4: should use per_cpu_ptr() in dev_get_stats() (Jakub) v3: added a READ_ONCE() in netdev_core_stats_alloc() (Paolo) v2: add a missing include (reported by kernel test robot ) Change in netdev_core_stats_alloc() (Jakub) Signed-off-by: Eric Dumazet Cc: jeffreyji Reviewed-by: Brian Vazquez Reviewed-by: Jakub Kicinski Acked-by: Paolo Abeni Link: https://lore.kernel.org/r/20220311051420.2608812-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

tun: vxlan: Use netif_rx().

2022-03-07T11:40:40+00:00

Since commit baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.") the function netif_rx() can be used in preemptible/thread context as well as in interrupt context. Use netif_rx(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: David S. Miller

net: tun: track dropped skb via kfree_skb_reason()

2022-03-06T11:04:01+00:00

The TUN can be used as vhost-net backend. E.g, the tun_net_xmit() is the interface to forward the skb from TUN to vhost-net/virtio-net. However, there are many "goto drop" in the TUN driver. Therefore, the kfree_skb_reason() is involved at each "goto drop" to help userspace ftrace/ebpf to track the reason for the loss of packets. The below reasons are introduced: - SKB_DROP_REASON_DEV_READY - SKB_DROP_REASON_NOMEM - SKB_DROP_REASON_HDR_TRUNC - SKB_DROP_REASON_TAP_FILTER - SKB_DROP_REASON_TAP_TXFILTER Cc: Joao Martins Cc: Joe Jin Signed-off-by: Dongli Zhang Signed-off-by: David S. Miller

net: tun: split run_ebpf_filter() and pskb_trim() into different "if statement"

2022-03-06T11:04:01+00:00

No functional change. Just to split the if statement into different conditions to use kfree_skb_reason() to trace the reason later. Cc: Joao Martins Cc: Joe Jin Signed-off-by: Dongli Zhang Reviewed-by: David Ahern Signed-off-by: David S. Miller

tuntap: add sanity checks about msg_controllen in sendmsg

2022-03-03T06:00:59+00:00

In patch [1], tun_msg_ctl was added to allow pass batched xdp buffers to tun_sendmsg. Although we donot use msg_controllen in this path, we should check msg_controllen to make sure the caller pass a valid msg_ctl. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fe8dd45bb7556246c6b76277b1ba4296c91c2505 Reported-by: Eric Dumazet Suggested-by: Jason Wang Signed-off-by: Harold Huang Acked-by: Jason Wang Link: https://lore.kernel.org/r/20220303022441.383865-1-baymaxhuang@gmail.com Signed-off-by: Jakub Kicinski

tun: support NAPI for packets received from batched XDP buffs

2022-03-02T01:27:53+00:00

In tun, NAPI is supported and we can also use NAPI in the path of batched XDP buffs to accelerate packet processing. What is more, after we use NAPI, GRO is also supported. The iperf shows that the throughput of single stream could be improved from 4.5Gbps to 9.2Gbps. Additionally, 9.2 Gbps nearly reachs the line speed of the phy nic and there is still about 15% idle cpu core remaining on the vhost thread. Test topology: [iperf server]<--->tap<--->dpdk testpmd<--->phy nic<--->[iperf client] Iperf stream: iperf3 -c 10.0.0.2 -i 1 -t 10 Before: ... [ 5] 5.00-6.00 sec 558 MBytes 4.68 Gbits/sec 0 1.50 MBytes [ 5] 6.00-7.00 sec 556 MBytes 4.67 Gbits/sec 1 1.35 MBytes [ 5] 7.00-8.00 sec 556 MBytes 4.67 Gbits/sec 2 1.18 MBytes [ 5] 8.00-9.00 sec 559 MBytes 4.69 Gbits/sec 0 1.48 MBytes [ 5] 9.00-10.00 sec 556 MBytes 4.67 Gbits/sec 1 1.33 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 5.39 GBytes 4.63 Gbits/sec 72 sender [ 5] 0.00-10.04 sec 5.39 GBytes 4.61 Gbits/sec receiver After: ... [ 5] 5.00-6.00 sec 1.07 GBytes 9.19 Gbits/sec 0 1.55 MBytes [ 5] 6.00-7.00 sec 1.08 GBytes 9.30 Gbits/sec 0 1.63 MBytes [ 5] 7.00-8.00 sec 1.08 GBytes 9.25 Gbits/sec 0 1.72 MBytes [ 5] 8.00-9.00 sec 1.08 GBytes 9.25 Gbits/sec 77 1.31 MBytes [ 5] 9.00-10.00 sec 1.08 GBytes 9.24 Gbits/sec 0 1.48 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 10.8 GBytes 9.28 Gbits/sec 166 sender [ 5] 0.00-10.04 sec 10.8 GBytes 9.24 Gbits/sec receiver Reported-at: https://lore.kernel.org/all/CACGkMEvTLG0Ayg+TtbN4q4pPW-ycgCCs3sC3-TF8cuRTf7Pp1A@mail.gmail.com Signed-off-by: Harold Huang Acked-by: Jason Wang Link: https://lore.kernel.org/r/20220228033805.1579435-1-baymaxhuang@gmail.com Signed-off-by: Jakub Kicinski