virtio/9p: verify device has config space
Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/9p needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index daa749c..d8e376a 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -524,6 +524,12 @@
int err;
struct virtio_chan *chan;
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "%s failure: config access disabled\n",
+ __func__);
+ return -EINVAL;
+ }
+
chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
if (!chan) {
pr_err("Failed to allocate virtio 9P channel\n");