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

Fam Zheng posted 1 patch 7 years ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20170317113353.26297-1-famz@redhat.com
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hw/virtio/virtio-bus.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
[Qemu-devel] [PATCH for-2.9] virtio: Fix error handling in virtio_bus_device_plugged
Posted by Fam Zheng 7 years ago
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>
---
 hw/virtio/virtio-bus.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index a886011..ef76919 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"
@@ -48,21 +49,34 @@ 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);
     }
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
 
     if (klass->get_dma_as != NULL && has_iommu) {
         virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
-- 
2.9.3


Re: [Qemu-devel] [PATCH for-2.9] virtio: Fix error handling in virtio_bus_device_plugged
Posted by Cornelia Huck 7 years ago
On Fri, 17 Mar 2017 19:33:53 +0800
Fam Zheng <famz@redhat.com> 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>
> ---
>  hw/virtio/virtio-bus.c | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>


Re: [Qemu-devel] [PATCH for-2.9] virtio: Fix error handling in virtio_bus_device_plugged
Posted by Andrew Jones 7 years ago
On Fri, Mar 17, 2017 at 07:33:53PM +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>
> ---
>  hw/virtio/virtio-bus.c | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
> index a886011..ef76919 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"
> @@ -48,21 +49,34 @@ 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);

Did you intend to change this errp to &local_err, as well? If not,
then the body of the below hunk is unreachable, as local_err can
never be non-null there.

Thanks,
drew

>      }
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
>  
>      if (klass->get_dma_as != NULL && has_iommu) {
>          virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
> -- 
> 2.9.3
> 
> 

Re: [Qemu-devel] [PATCH for-2.9] virtio: Fix error handling in virtio_bus_device_plugged
Posted by Cornelia Huck 7 years ago
On Fri, 17 Mar 2017 13:18:16 +0100
Andrew Jones <drjones@redhat.com> wrote:

> On Fri, Mar 17, 2017 at 07:33:53PM +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>
> > ---
> >  hw/virtio/virtio-bus.c | 18 ++++++++++++++++--
> >  1 file changed, 16 insertions(+), 2 deletions(-)

> >  
> >      if (klass->device_plugged != NULL) {
> >          klass->device_plugged(qbus->parent, errp);
> 
> Did you intend to change this errp to &local_err, as well? If not,
> then the body of the below hunk is unreachable, as local_err can
> never be non-null there.

Oh, I managed to overlook this.

So my r-b applies if this is changed to use local_err :)

> 
> Thanks,
> drew
> 
> >      }
> > +    if (local_err) {
> > +        error_propagate(errp, local_err);
> > +        return;
> > +    }
> >  
> >      if (klass->get_dma_as != NULL && has_iommu) {
> >          virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
> > -- 
> > 2.9.3
> > 
> > 
> 
> 


Re: [Qemu-devel] [PATCH for-2.9] virtio: Fix error handling in virtio_bus_device_plugged
Posted by Fam Zheng 7 years ago
On Fri, 03/17 13:18, Andrew Jones wrote:
> On Fri, Mar 17, 2017 at 07:33:53PM +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>
> > ---
> >  hw/virtio/virtio-bus.c | 18 ++++++++++++++++--
> >  1 file changed, 16 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
> > index a886011..ef76919 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"
> > @@ -48,21 +49,34 @@ 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);
> 
> Did you intend to change this errp to &local_err, as well? If not,
> then the body of the below hunk is unreachable, as local_err can
> never be non-null there.

Yes, this is an overlook.

Fam

> 
> Thanks,
> drew
> 
> >      }
> > +    if (local_err) {
> > +        error_propagate(errp, local_err);
> > +        return;
> > +    }
> >  
> >      if (klass->get_dma_as != NULL && has_iommu) {
> >          virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
> > -- 
> > 2.9.3
> > 
> >