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Commit d90c92fe authored by Santiago Leon's avatar Santiago Leon Committed by David S. Miller
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ibmveth: Fix alignment of rx queue bug 

This patch fixes a bug found by Nish Aravamudan
(https://lkml.org/lkml/2012/5/15/220) where the driver is not following
the spec (it is not aligning the rx buffer on a 16-byte boundary) and the
hypervisor aborts the registration, making the device unusable.

The fix follows BenH's recommendation (https://lkml.org/lkml/2012/7/20/461

)
to replace the kmalloc+map for a single call to dma_alloc_coherent()
because that function always aligns to a 16-byte boundary.

The stable trees will run into this bug whenever the rx buffer kmalloc call
returns something not aligned on a 16-byte boundary.

Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarSantiago Leon <santil@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d013ef2a

drivers/net/ethernet/ibm/ibmveth.c

+9 −17
Original line number Diff line number Diff line
@@ -472,14 +472,9 @@ static void ibmveth_cleanup(struct ibmveth_adapter *adapter) 
	}



	if (adapter->rx_queue.queue_addr != NULL) {

		if (!dma_mapping_error(dev, adapter->rx_queue.queue_dma)) {

			dma_unmap_single(dev,

					adapter->rx_queue.queue_dma,

					adapter->rx_queue.queue_len,

					DMA_BIDIRECTIONAL);

			adapter->rx_queue.queue_dma = DMA_ERROR_CODE;

		}

		kfree(adapter->rx_queue.queue_addr);

		dma_free_coherent(dev, adapter->rx_queue.queue_len,

				  adapter->rx_queue.queue_addr,

				  adapter->rx_queue.queue_dma);

		adapter->rx_queue.queue_addr = NULL;

	}
@@ -556,10 +551,13 @@ static int ibmveth_open(struct net_device *netdev) 
		goto err_out;

	}



	dev = &adapter->vdev->dev;



	adapter->rx_queue.queue_len = sizeof(struct ibmveth_rx_q_entry) *

						rxq_entries;

	adapter->rx_queue.queue_addr = kmalloc(adapter->rx_queue.queue_len,

						GFP_KERNEL);

	adapter->rx_queue.queue_addr =

	    dma_alloc_coherent(dev, adapter->rx_queue.queue_len,

			       &adapter->rx_queue.queue_dma, GFP_KERNEL);



	if (!adapter->rx_queue.queue_addr) {

		netdev_err(netdev, "unable to allocate rx queue pages\n");
@@ -567,19 +565,13 @@ static int ibmveth_open(struct net_device *netdev) 
		goto err_out;

	}



	dev = &adapter->vdev->dev;



	adapter->buffer_list_dma = dma_map_single(dev,

			adapter->buffer_list_addr, 4096, DMA_BIDIRECTIONAL);

	adapter->filter_list_dma = dma_map_single(dev,

			adapter->filter_list_addr, 4096, DMA_BIDIRECTIONAL);

	adapter->rx_queue.queue_dma = dma_map_single(dev,

			adapter->rx_queue.queue_addr,

			adapter->rx_queue.queue_len, DMA_BIDIRECTIONAL);



	if ((dma_mapping_error(dev, adapter->buffer_list_dma)) ||

	    (dma_mapping_error(dev, adapter->filter_list_dma)) ||

	    (dma_mapping_error(dev, adapter->rx_queue.queue_dma))) {

	    (dma_mapping_error(dev, adapter->filter_list_dma))) {

		netdev_err(netdev, "unable to map filter or buffer list "

			   "pages\n");

		rc = -ENOMEM;