virtio: console: Ignore port name update request if name already set
authorAmit Shah <amit.shah@redhat.com>
Wed, 14 Sep 2011 07:36:40 +0000 (13:06 +0530)
committerRusty Russell <rusty@rustcorp.com.au>
Wed, 2 Nov 2011 01:10:59 +0000 (11:40 +1030)
We don't allow port name changes dynamically for a port.  So any
requests by the host to change the name are ignored.

Before this patch, if the hypervisor sent a port name while we had one
set already, we would leak memory equivalent to the size of the old
name.

This scenario wasn't expected so far, but with the suspend-resume
support, we'll send the VIRTIO_CONSOLE_PORT_READY message after restore,
which can get us into this situation.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
drivers/char/virtio_console.c

index 10280a2..5397884 100644 (file)
@@ -1394,6 +1394,13 @@ static void handle_control_message(struct ports_device *portdev,
                break;
        case VIRTIO_CONSOLE_PORT_NAME:
                /*
+                * If we woke up after hibernation, we can get this
+                * again.  Skip it in that case.
+                */
+               if (port->name)
+                       break;
+
+               /*
                 * Skip the size of the header and the cpkt to get the size
                 * of the name that was sent
                 */