Re: [PATCH net] ibmveth: Convert multicast list size for little-endian systems

[Joe Perches]

On Mon, 2019-08-12 at 12:43 -0500, Thomas Falcon wrote:
> The ibm,mac-address-filters property defines the maximum number of
> addresses the hypervisor's multicast filter list can support. It is
> encoded as a big-endian integer in the OF device tree, but the virtual
> ethernet driver does not convert it for use by little-endian systems.
> As a result, the driver is not behaving as it should on affected systems
> when a large number of multicast addresses are assigned to the device.
> 
> Reported-by: Hangbin Liu <liuhang...@gmail.com>
> Signed-off-by: Thomas Falcon <tlfal...@linux.ibm.com>
> ---
>  drivers/net/ethernet/ibm/ibmveth.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/ibm/ibmveth.c 
> b/drivers/net/ethernet/ibm/ibmveth.c
> index d654c23..b50a6cf 100644
> --- a/drivers/net/ethernet/ibm/ibmveth.c
> +++ b/drivers/net/ethernet/ibm/ibmveth.c
> @@ -1645,7 +1645,7 @@ static int ibmveth_probe(struct vio_dev *dev, const 
> struct vio_device_id *id)
>  
>       adapter->vdev = dev;
>       adapter->netdev = netdev;
> -     adapter->mcastFilterSize = *mcastFilterSize_p;
> +     adapter->mcastFilterSize = be32_to_cpu(*mcastFilterSize_p);
>       adapter->pool_config = 0;
>  
>       netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);

Perhaps to keep sparse happy too: (untested)
---
 drivers/net/ethernet/ibm/ibmveth.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c 
b/drivers/net/ethernet/ibm/ibmveth.c
index d654c234aaf7..90539d7ce565 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1605,7 +1605,7 @@ static int ibmveth_probe(struct vio_dev *dev, const 
struct vio_device_id *id)
        struct net_device *netdev;
        struct ibmveth_adapter *adapter;
        unsigned char *mac_addr_p;
-       unsigned int *mcastFilterSize_p;
+       __be32 *mcastFilterSize_p;
        long ret;
        unsigned long ret_attr;
 
@@ -1627,7 +1627,7 @@ static int ibmveth_probe(struct vio_dev *dev, const 
struct vio_device_id *id)
                return -EINVAL;
        }
 
-       mcastFilterSize_p = (unsigned int *)vio_get_attribute(dev,
+       mcastFilterSize_p = (__be32 *)vio_get_attribute(dev,
                                                VETH_MCAST_FILTER_SIZE, NULL);
        if (!mcastFilterSize_p) {
                dev_err(&dev->dev, "Can't find VETH_MCAST_FILTER_SIZE "
@@ -1645,7 +1645,7 @@ static int ibmveth_probe(struct vio_dev *dev, const 
struct vio_device_id *id)
 
        adapter->vdev = dev;
        adapter->netdev = netdev;
-       adapter->mcastFilterSize = *mcastFilterSize_p;
+       adapter->mcastFilterSize = be32_to_cpu(*mcastFilterSize_p);
        adapter->pool_config = 0;
 
        netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);