Re: [Qemu-devel] [PATCH for-2.9 v2] virtio: Fix error handling in virtio_bus_device_plugged

[Andrew Jones <drjones@redhat.com>]

On Fri, Mar 17, 2017 at 08:32:42PM +0800, Fam Zheng wrote:
> For one thing we shouldn't continue if an error happened, for the other
> two steps failing can cause an abort() in error_setg because we reuse
> the same errp blindly.
> 
> Add error handling checks to fix both issues.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> 
> ---
> 
> v2: Don't forget the last errp -> &local_err. [Drew]
> ---
>  hw/virtio/virtio-bus.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
> index a886011..3042232 100644
> --- a/hw/virtio/virtio-bus.c
> +++ b/hw/virtio/virtio-bus.c
> @@ -25,6 +25,7 @@
>  #include "qemu/osdep.h"
>  #include "hw/hw.h"
>  #include "qemu/error-report.h"
> +#include "qapi/error.h"
>  #include "hw/qdev.h"
>  #include "hw/virtio/virtio-bus.h"
>  #include "hw/virtio/virtio.h"
> @@ -48,20 +49,33 @@ void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
>      VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
>      VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
>      bool has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
> +    Error *local_err = NULL;
>  
>      DPRINTF("%s: plug device.\n", qbus->name);
>  
>      if (klass->pre_plugged != NULL) {
> -        klass->pre_plugged(qbus->parent, errp);
> +        klass->pre_plugged(qbus->parent, &local_err);
> +        if (local_err) {
> +            error_propagate(errp, local_err);
> +            return;
> +        }
>      }
>  
>      /* Get the features of the plugged device. */
>      assert(vdc->get_features != NULL);
>      vdev->host_features = vdc->get_features(vdev, vdev->host_features,
> -                                            errp);
> +                                            &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
>  
>      if (klass->device_plugged != NULL) {
> -        klass->device_plugged(qbus->parent, errp);
> +        klass->device_plugged(qbus->parent, &local_err);
> +    }
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
>      }
>  
>      if (klass->get_dma_as != NULL && has_iommu) {
> -- 
> 2.9.3
> 
>

Reviewed-by: Andrew Jones <drjones@redhat.com>