[Qemu-devel] [PATCH v2] virtio-rng: Fix crash with non-default backend

[Cole Robinson <crobinso@redhat.com>]

'default_backend' isn't always set, but 'rng' is, so use that.

$ ./x86_64-softmmu/qemu-system-x86_64 -object rng-random,id=rng0,filename=/dev/random -device virtio-rng-pci,rng=rng0
Segmentation fault (core dumped)

Regressed with virtio refactoring in 59ccd20a9ac719cff82180429458728f03ec612f

CC: qemu-stable@nongnu.org
Signed-off-by: Cole Robinson <crobinso@redhat.com>
---

Notes:
    v2: Fix other instances in s390x code, pointed out by Frederic

 hw/s390x/s390-virtio-bus.c | 2 +-
 hw/s390x/virtio-ccw.c      | 2 +-
 hw/virtio/virtio-pci.c     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index a1cdfb0..207eb82 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -300,7 +300,7 @@ static int s390_virtio_rng_init(VirtIOS390Device *s390_dev)
     }
 
     object_property_set_link(OBJECT(dev),
-                             OBJECT(dev->vdev.conf.default_backend), "rng",
+                             OBJECT(dev->vdev.conf.rng), "rng",
                              NULL);
 
     return s390_virtio_device_init(s390_dev, VIRTIO_DEVICE(vdev));
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 5f5e267..7dcd98d 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -744,7 +744,7 @@ static int virtio_ccw_rng_init(VirtioCcwDevice *ccw_dev)
     }
 
     object_property_set_link(OBJECT(dev),
-                             OBJECT(dev->vdev.conf.default_backend), "rng",
+                             OBJECT(dev->vdev.conf.rng), "rng",
                              NULL);
 
     return virtio_ccw_device_init(ccw_dev, VIRTIO_DEVICE(vdev));
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 444b71a..b070b64 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1455,7 +1455,7 @@ static int virtio_rng_pci_init(VirtIOPCIProxy *vpci_dev)
     }
 
     object_property_set_link(OBJECT(vrng),
-                             OBJECT(vrng->vdev.conf.default_backend), "rng",
+                             OBJECT(vrng->vdev.conf.rng), "rng",
                              NULL);
 
     return 0;
-- 
1.8.2.1