From: Mark McLoughlin Date: Tue, 3 Feb 2009 03:03:53 +0000 (+1030) Subject: virtio-pci: do not oops on config change if driver not loaded X-Git-Tag: firefly_0821_release~15679 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3fff0179e33cd7d0a688dab65700c46ad089e934;p=firefly-linux-kernel-4.4.55.git virtio-pci: do not oops on config change if driver not loaded The host really shouldn't be notifying us of config changes before the device status is VIRTIO_CONFIG_S_DRIVER or VIRTIO_CONFIG_S_DRIVER_OK. However, if we do happen to be interrupted while we're not attached to a driver, we really shouldn't oops. Prevent this simply by checking that device->driver is non-NULL before trying to notify the driver of config changes. Problem observed by doing a "set_link virtio.0 down" with QEMU before the net driver had been loaded. Signed-off-by: Mark McLoughlin Signed-off-by: Rusty Russell Signed-off-by: Linus Torvalds --- diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index bef6b45e8a5c..330aacbdec1f 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -192,7 +192,7 @@ static irqreturn_t vp_interrupt(int irq, void *opaque) drv = container_of(vp_dev->vdev.dev.driver, struct virtio_driver, driver); - if (drv->config_changed) + if (drv && drv->config_changed) drv->config_changed(&vp_dev->vdev); }