From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Date: Mon, 28 Oct 2013 23:10:47 +0000 (+1030)
Subject: virtio_net: verify if queue is broken after virtqueue_get_buf()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=047b9b94951dba2e93c65a582ae2bce25c960b86;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

virtio_net: verify if queue is broken after virtqueue_get_buf()

If a virtqueue_get_buf() call returns a NULL pointer a possibly endless while
loop should be avoided by checking for a broken virtqueue.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ff208d2787d3..057ea133cd2b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -825,7 +825,8 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
 	/* Spin for a response, the kick causes an ioport write, trapping
 	 * into the hypervisor, so the request should be handled immediately.
 	 */
-	while (!virtqueue_get_buf(vi->cvq, &tmp))
+	while (!virtqueue_get_buf(vi->cvq, &tmp) &&
+	       !virtqueue_is_broken(vi->cvq))
 		cpu_relax();
 
 	return status == VIRTIO_NET_OK;