IB/mad: Check and handle potential DMA mapping errors

Running with DMA_API_DEBUG enabled and not checking for DMA mapping
errors triggers a kernel stack trace with "DMA-API: device driver
failed to check map error" message.  Add these checks to the MAD
module, both to be be more robust and also eliminate these
false-positive stack traces.

Signed-off-by: Yan Burman <yanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 4c837e66516b..ab31f136d04b 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1022,12 +1022,21 @@ int ib_send_mad(struct ib_mad_send_wr_private *mad_send_wr)
                                         mad_send_wr->send_buf.mad,
                                         sge[0].length,
                                         DMA_TO_DEVICE);
+        if (unlikely(ib_dma_mapping_error(mad_agent->device, sge[0].addr)))
+                return -ENOMEM;
+
         mad_send_wr->header_mapping = sge[0].addr;
 
         sge[1].addr = ib_dma_map_single(mad_agent->device,
                                         ib_get_payload(mad_send_wr),
                                         sge[1].length,
                                         DMA_TO_DEVICE);
+        if (unlikely(ib_dma_mapping_error(mad_agent->device, sge[1].addr))) {
+                ib_dma_unmap_single(mad_agent->device,
+                                    mad_send_wr->header_mapping,
+                                    sge[0].length, DMA_TO_DEVICE);
+                return -ENOMEM;
+        }
         mad_send_wr->payload_mapping = sge[1].addr;
 
         spin_lock_irqsave(&qp_info->send_queue.lock, flags);
@@ -2590,6 +2599,11 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info,
                                                  sizeof *mad_priv -
                                                    sizeof mad_priv->header,
                                                  DMA_FROM_DEVICE);
+                if (unlikely(ib_dma_mapping_error(qp_info->port_priv->device,
+                                                  sg_list.addr))) {
+                        ret = -ENOMEM;
+                        break;
+                }
                 mad_priv->header.mapping = sg_list.addr;
                 recv_wr.wr_id = (unsigned long)&mad_priv->header.mad_list;
                 mad_priv->header.mad_list.mad_queue = recv_queue;