[PATCH 3.8 145/166] virtio: delete napi structures from netdev before releasing memory

Kamal Mostafa
2014-01-15T21:52:39Z

From: Andrey Vagin <avagin@openvz.org>

[ Upstream commit d4fb84eefe5164f6a6ea51d0a9e26280c661a0dd ]

free_netdev calls netif_napi_del too, but it's too late, because napi
structures are placed on vi->rq. netif_napi_add() is called from
virtnet_alloc_queues.

general protection fault: 0000 [#1] SMP
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in: ip6table_filter ip6_tables iptable_filter ip_tables virtio_balloon pcspkr virtio_net(-) i2c_pii
CPU: 1 PID: 347 Comm: rmmod Not tainted 3.13.0-rc2+ #171
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff8800b779c420 ti: ffff8800379e0000 task.ti: ffff8800379e0000
RIP: 0010:[<ffffffff81322e19>] [<ffffffff81322e19>] __list_del_entry+0x29/0xd0
RSP: 0018:ffff8800379e1dd0 EFLAGS: 00010a83
RAX: 6b6b6b6b6b6b6b6b RBX: ffff8800379c2fd0 RCX: dead000000200200
RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000001 RDI: ffff8800379c2fd0
RBP: ffff8800379e1dd0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8800379c2f90
R13: ffff880037839160 R14: 0000000000000000 R15: 00000000013352f0
FS: 00007f1400e34740(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f464124c763 CR3: 00000000b68cf000 CR4: 00000000000006e0
Stack:
ffff8800379e1df0 ffffffff8155beab 6b6b6b6b6b6b6b2b ffff8800378391c0
ffff8800379e1e18 ffffffff8156499b ffff880037839be0 ffff880037839d20
ffff88003779d3f0 ffff8800379e1e38 ffffffffa003477c ffff88003779d388
Call Trace:
[<ffffffff8155beab>] netif_napi_del+0x1b/0x80
[<ffffffff8156499b>] free_netdev+0x8b/0x110
[<ffffffffa003477c>] virtnet_remove+0x7c/0x90 [virtio_net]
[<ffffffff813ae323>] virtio_dev_remove+0x23/0x80
[<ffffffff813f62ef>] __device_release_driver+0x7f/0xf0
[<ffffffff813f6ca0>] driver_detach+0xc0/0xd0
[<ffffffff813f5f28>] bus_remove_driver+0x58/0xd0
[<ffffffff813f72ec>] driver_unregister+0x2c/0x50
[<ffffffff813ae65e>] unregister_virtio_driver+0xe/0x10
[<ffffffffa0036942>] virtio_net_driver_exit+0x10/0x6ce [virtio_net]
[<ffffffff810d7cf2>] SyS_delete_module+0x172/0x220
[<ffffffff810a732d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff810f5d4c>] ? __audit_syscall_entry+0x9c/0xf0
[<ffffffff81677f69>] system_call_fastpath+0x16/0x1b
Code: 00 00 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de 48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00
RIP [<ffffffff81322e19>] __list_del_entry+0x29/0xd0
RSP <ffff8800379e1dd0>
---[ end trace d5931cd3f87c9763 ]---

Fixes: 986a4f4d452d (virtio_net: multiqueue support)
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/net/virtio_net.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c3bcb4a..fa2385a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1265,6 +1265,11 @@ static void virtnet_config_changed(struct virtio_device *vdev)

static void virtnet_free_queues(struct virtnet_info *vi)
{
+ int i;
+
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ netif_napi_del(&vi->rq[i].napi);
+
kfree(vi->rq);
kfree(vi->sq);
}
--
1.8.3.2