From 0a504779d312ab20b9dbe3c8f1c66f395f80e2eb Mon Sep 17 00:00:00 2001 From: Greg Ungerer Date: Tue, 4 Mar 2008 16:52:01 +1000 Subject: m68knommu: fix fec driver interrupt races The FEC driver has a common interrupt handler for all interrupt event types. It is raised on a number of distinct interrupt vectors. This handler can't be re-entered while processing an interrupt, so make sure all requested vectors are flagged as IRQF_DISABLED. Signed-off-by: Greg Ungerer Signed-off-by: Linus Torvalds --- drivers/net/fec.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/fec.c b/drivers/net/fec.c index 0fbf1bb..d7a3ea8 100644 --- a/drivers/net/fec.c +++ b/drivers/net/fec.c @@ -1253,7 +1253,7 @@ static void __inline__ fec_request_intrs(struct net_device *dev) /* Setup interrupt handlers. */ for (idp = id; idp->name; idp++) { - if (request_irq(idp->irq, idp->handler, 0, idp->name, dev) != 0) + if (request_irq(idp->irq, idp->handler, IRQF_DISABLED, idp->name, dev) != 0) printk("FEC: Could not allocate %s IRQ(%d)!\n", idp->name, idp->irq); } @@ -1382,7 +1382,7 @@ static void __inline__ fec_request_intrs(struct net_device *dev) /* Setup interrupt handlers. */ for (idp = id; idp->name; idp++) { - if (request_irq(b+idp->irq, fec_enet_interrupt, 0, idp->name, dev) != 0) + if (request_irq(b+idp->irq, fec_enet_interrupt, IRQF_DISABLED, idp->name, dev) != 0) printk("FEC: Could not allocate %s IRQ(%d)!\n", idp->name, b+idp->irq); } @@ -1553,7 +1553,7 @@ static void __inline__ fec_request_intrs(struct net_device *dev) /* Setup interrupt handlers. */ for (idp = id; idp->name; idp++) { - if (request_irq(b+idp->irq,fec_enet_interrupt,0,idp->name,dev)!=0) + if (request_irq(b+idp->irq, fec_enet_interrupt, IRQF_DISABLED, idp->name,dev) != 0) printk("FEC: Could not allocate %s IRQ(%d)!\n", idp->name, b+idp->irq); } @@ -1680,7 +1680,7 @@ static void __inline__ fec_request_intrs(struct net_device *dev) /* Setup interrupt handlers. */ for (idp = id; idp->name; idp++) { - if (request_irq(b+idp->irq,fec_enet_interrupt,0,idp->name,dev)!=0) + if (request_irq(b+idp->irq, fec_enet_interrupt, IRQF_DISABLED, idp->name,dev) != 0) printk("FEC: Could not allocate %s IRQ(%d)!\n", idp->name, b+idp->irq); } -- cgit v1.1 From da74e89d40995600b3b07ac500084920247687ce Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Fri, 29 Feb 2008 16:24:50 +0530 Subject: virtio: Enable netpoll interface for netconsole logging Add a new poll_controller handler that the netpoll interface needs. This enables netconsole logging from a kvm guest over the virtio net interface. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell --- drivers/net/virtio_net.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/net') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 19fd4cb..e575df8 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -294,6 +294,15 @@ again: return 0; } +#ifdef CONFIG_NET_POLL_CONTROLLER +static void virtnet_netpoll(struct net_device *dev) +{ + struct virtnet_info *vi = netdev_priv(dev); + + napi_schedule(&vi->napi); +} +#endif + static int virtnet_open(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); @@ -336,6 +345,9 @@ static int virtnet_probe(struct virtio_device *vdev) dev->stop = virtnet_close; dev->hard_start_xmit = start_xmit; dev->features = NETIF_F_HIGHDMA; +#ifdef CONFIG_NET_POLL_CONTROLLER + dev->poll_controller = virtnet_netpoll; +#endif SET_NETDEV_DEV(dev, &vdev->dev); /* Do we support "hardware" checksums? */ -- cgit v1.1 From 4265f161b6bb7b31163671329b1142b9023bf4e3 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 14 Mar 2008 14:17:05 +0100 Subject: virtio: fix race in enable_cb There is a race in virtio_net, dealing with disabling/enabling the callback. I saw the following oops: kernel BUG at /space/kvm/drivers/virtio/virtio_ring.c:218! illegal operation: 0001 [#1] SMP Modules linked in: sunrpc dm_mod CPU: 2 Not tainted 2.6.25-rc1zlive-host-10623-gd358142-dirty #99 Process swapper (pid: 0, task: 000000000f85a610, ksp: 000000000f873c60) Krnl PSW : 0404300180000000 00000000002b81a6 (vring_disable_cb+0x16/0x20) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:3 PM:0 EA:3 Krnl GPRS: 0000000000000001 0000000000000001 0000000010005800 0000000000000001 000000000f3a0900 000000000f85a610 0000000000000000 0000000000000000 0000000000000000 000000000f870000 0000000000000000 0000000000001237 000000000f3a0920 000000000010ff74 00000000002846f6 000000000fa0bcd8 Krnl Code: 00000000002b819a: a7110001 tmll %r1,1 00000000002b819e: a7840004 brc 8,2b81a6 00000000002b81a2: a7f40001 brc 15,2b81a4 >00000000002b81a6: a51b0001 oill %r1,1 00000000002b81aa: 40102000 sth %r1,0(%r2) 00000000002b81ae: 07fe bcr 15,%r14 00000000002b81b0: eb7ff0380024 stmg %r7,%r15,56(%r15) 00000000002b81b6: a7f13e00 tmll %r15,15872 Call Trace: ([<000000000fa0bcd0>] 0xfa0bcd0) [<00000000002b8350>] vring_interrupt+0x5c/0x6c [<000000000010ab08>] do_extint+0xb8/0xf0 [<0000000000110716>] ext_no_vtime+0x16/0x1a [<0000000000107e72>] cpu_idle+0x1c2/0x1e0 The problem can be triggered with a high amount of host->guest traffic. I think its the following race: poll says netif_rx_complete poll calls enable_cb enable_cb opens the interrupt mask a new packet comes, an interrupt is triggered----\ enable_cb sees that there is more work | enable_cb disables the interrupt | . V . interrupt is delivered . skb_recv_done does atomic napi test, ok some waiting disable_cb is called->check fails->bang! . poll would do napi check poll would do disable_cb The fix is to let enable_cb not disable the interrupt again, but expect the caller to do the cleanup if it returns false. In that case, the interrupt is only disabled, if the napi test_set_bit was successful. Signed-off-by: Christian Borntraeger Signed-off-by: Rusty Russell (cleaned up doco) --- drivers/net/virtio_net.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index e575df8..b58472c 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -203,8 +203,11 @@ again: if (received < budget) { netif_rx_complete(vi->dev, napi); if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) - && netif_rx_reschedule(vi->dev, napi)) + && napi_schedule_prep(napi)) { + vi->rvq->vq_ops->disable_cb(vi->rvq); + __netif_rx_schedule(vi->dev, napi); goto again; + } } return received; @@ -278,10 +281,11 @@ again: pr_debug("%s: virtio not prepared to send\n", dev->name); netif_stop_queue(dev); - /* Activate callback for using skbs: if this fails it + /* Activate callback for using skbs: if this returns false it * means some were used in the meantime. */ if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) { - printk("Unlikely: restart svq failed\n"); + printk("Unlikely: restart svq race\n"); + vi->svq->vq_ops->disable_cb(vi->svq); netif_start_queue(dev); goto again; } -- cgit v1.1