From 017b29c38c0dc8aece778b44fad32adf8862c188 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Mon, 20 Feb 2017 11:50:20 +0800 Subject: [PATCH] virito-net: set queues after reset during xdp_set We set queues before reset which will cause a crash[1]. This is because is_xdp_raw_buffer_queue() depends on the old xdp queue pairs number to do the correct detection. So fix this by - passing xdp queue pairs and current queue pairs to virtnet_reset() - change vi->xdp_qp after reset but before refill, to make sure both free_unused_bufs() and refill can make correct detection of XDP. - remove the duplicated queue pairs setting before virtnet_reset() since we will do it inside virtnet_reset() [1] [ 74.328168] general protection fault: 0000 [#1] SMP [ 74.328625] Modules linked in: nfsd xfs libcrc32c virtio_net virtio_pci [ 74.329117] CPU: 0 PID: 2849 Comm: xdp2 Not tainted 4.10.0-rc7+ #499 [ 74.329577] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 [ 74.330424] task: ffff88007a894000 task.stack: ffffc90004388000 [ 74.330844] RIP: 0010:skb_release_head_state+0x28/0x80 [ 74.331298] RSP: 0018:ffffc9000438b8d0 EFLAGS: 00010206 [ 74.331676] RAX: 0000000000000000 RBX: ffff88007ad96300 RCX: 0000000000000000 [ 74.332217] RDX: ffff88007fc137a8 RSI: ffff88007fc0db28 RDI: 0001bf00000001be [ 74.332758] RBP: ffffc9000438b8d8 R08: 000000000005008f R09: 00000000000005f9 [ 74.333274] R10: ffff88007d001700 R11: ffffffff820a8a4d R12: ffff88007ad96300 [ 74.333787] R13: 0000000000000002 R14: ffff880036604000 R15: 000077ff80000000 [ 74.334308] FS: 00007fc70d8a7b40(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 [ 74.334891] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 74.335314] CR2: 00007fff4144a710 CR3: 000000007ab56000 CR4: 00000000003406f0 [ 74.335830] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 74.336373] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 74.336895] Call Trace: [ 74.337086] skb_release_all+0xd/0x30 [ 74.337356] consume_skb+0x2c/0x90 [ 74.337607] free_unused_bufs+0x1ff/0x270 [virtio_net] [ 74.337988] ? vp_synchronize_vectors+0x3b/0x60 [virtio_pci] [ 74.338398] virtnet_xdp+0x21e/0x440 [virtio_net] [ 74.338741] dev_change_xdp_fd+0x101/0x140 [ 74.339048] do_setlink+0xcf4/0xd20 [ 74.339304] ? symcmp+0xf/0x20 [ 74.339529] ? mls_level_isvalid+0x52/0x60 [ 74.339828] ? mls_range_isvalid+0x43/0x50 [ 74.340135] ? nla_parse+0xa0/0x100 [ 74.340400] rtnl_setlink+0xd4/0x120 [ 74.340664] ? cpumask_next_and+0x30/0x50 [ 74.340966] rtnetlink_rcv_msg+0x7f/0x1f0 [ 74.341259] ? sock_has_perm+0x59/0x60 [ 74.341586] ? napi_consume_skb+0xe2/0x100 [ 74.342010] ? rtnl_newlink+0x890/0x890 [ 74.342435] netlink_rcv_skb+0x92/0xb0 [ 74.342846] rtnetlink_rcv+0x23/0x30 [ 74.343277] netlink_unicast+0x162/0x210 [ 74.343677] netlink_sendmsg+0x2db/0x390 [ 74.343968] sock_sendmsg+0x33/0x40 [ 74.344233] SYSC_sendto+0xee/0x160 [ 74.344482] ? SYSC_bind+0xb0/0xe0 [ 74.344806] ? sock_alloc_file+0x92/0x110 [ 74.345106] ? fd_install+0x20/0x30 [ 74.345360] ? sock_map_fd+0x3f/0x60 [ 74.345586] SyS_sendto+0x9/0x10 [ 74.345790] entry_SYSCALL_64_fastpath+0x1a/0xa9 [ 74.346086] RIP: 0033:0x7fc70d1b8f6d [ 74.346312] RSP: 002b:00007fff4144a708 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 74.346785] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fc70d1b8f6d [ 74.347244] RDX: 000000000000002c RSI: 00007fff4144a720 RDI: 0000000000000003 [ 74.347683] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 [ 74.348544] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff4144bd90 [ 74.349082] R13: 0000000000000002 R14: 0000000000000002 R15: 00007fff4144cda0 [ 74.349607] Code: 00 00 00 55 48 89 e5 53 48 89 fb 48 8b 7f 58 48 85 ff 74 0e 40 f6 c7 01 74 3d 48 c7 43 58 00 00 00 00 48 8b 7b 68 48 85 ff 74 05 ff 0f 74 20 48 8b 43 60 48 85 c0 74 14 65 8b 15 f3 ab 8d 7e [ 74.351008] RIP: skb_release_head_state+0x28/0x80 RSP: ffffc9000438b8d0 [ 74.351625] ---[ end trace fe6e19fd11cfc80b ]--- Fixes: 2de2f7f40ef9 ("virtio_net: XDP support for adjust_head") Cc: John Fastabend Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 28 ++++++++-------------------- 1 file changed, 8 insertions(+), 20 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 05a83dbc910d..ca489e064f85 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1752,7 +1752,7 @@ static int virtnet_restore_up(struct virtio_device *vdev) return err; } -static int virtnet_reset(struct virtnet_info *vi) +static int virtnet_reset(struct virtnet_info *vi, int curr_qp, int xdp_qp) { struct virtio_device *dev = vi->vdev; int ret; @@ -1770,10 +1770,11 @@ static int virtnet_reset(struct virtnet_info *vi) if (ret) goto err; + vi->xdp_queue_pairs = xdp_qp; ret = virtnet_restore_up(dev); if (ret) goto err; - ret = _virtnet_set_queues(vi, vi->curr_queue_pairs); + ret = _virtnet_set_queues(vi, curr_qp); if (ret) goto err; @@ -1790,7 +1791,7 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr); struct virtnet_info *vi = netdev_priv(dev); struct bpf_prog *old_prog; - u16 oxdp_qp, xdp_qp = 0, curr_qp; + u16 xdp_qp = 0, curr_qp; int i, err; if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) || @@ -1828,24 +1829,17 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) return PTR_ERR(prog); } - err = _virtnet_set_queues(vi, curr_qp + xdp_qp); - if (err) { - dev_warn(&dev->dev, "XDP Device queue allocation failure.\n"); - goto virtio_queue_err; - } - - oxdp_qp = vi->xdp_queue_pairs; - /* Changing the headroom in buffers is a disruptive operation because * existing buffers must be flushed and reallocated. This will happen * when a xdp program is initially added or xdp is disabled by removing * the xdp program resulting in number of XDP queues changing. */ if (vi->xdp_queue_pairs != xdp_qp) { - vi->xdp_queue_pairs = xdp_qp; - err = virtnet_reset(vi); - if (err) + err = virtnet_reset(vi, curr_qp + xdp_qp, xdp_qp); + if (err) { + dev_warn(&dev->dev, "XDP reset failure.\n"); goto virtio_reset_err; + } } netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp); @@ -1864,12 +1858,6 @@ virtio_reset_err: * error up to user space for resolution. The underlying reset hung on * us so not much we can do here. */ - dev_warn(&dev->dev, "XDP reset failure and queues unstable\n"); - vi->xdp_queue_pairs = oxdp_qp; -virtio_queue_err: - /* On queue set error we can unwind bpf ref count and user space can - * retry this is most likely an allocation failure. - */ if (prog) bpf_prog_sub(prog, vi->max_queue_pairs - 1); return err; -- 2.20.1