From 71791dc8bdea55eeb2a0caefe98a0b7450c6e0af Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Tue, 24 Mar 2020 13:23:40 +0000 Subject: [PATCH] net: axienet: Check for DMA mapping errors Especially with the default 32-bit DMA mask, DMA buffers are a limited resource, so their allocation can fail. So as the DMA API documentation requires, add error checking code after dma_map_single() calls to catch the case where we run out of "low" memory. Signed-off-by: Andre Przywara Signed-off-by: David S. Miller --- .../net/ethernet/xilinx/xilinx_axienet_main.c | 31 ++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 5c1b53944771..736ac1b7a052 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -248,6 +248,11 @@ static int axienet_dma_bd_init(struct net_device *ndev) skb->data, lp->max_frm_size, DMA_FROM_DEVICE); + if (dma_mapping_error(ndev->dev.parent, lp->rx_bd_v[i].phys)) { + netdev_err(ndev, "DMA mapping error\n"); + goto out; + } + lp->rx_bd_v[i].cntrl = lp->max_frm_size; } @@ -679,6 +684,7 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) dma_addr_t tail_p; struct axienet_local *lp = netdev_priv(ndev); struct axidma_bd *cur_p; + u32 orig_tail_ptr = lp->tx_bd_tail; num_frag = skb_shinfo(skb)->nr_frags; cur_p = &lp->tx_bd_v[lp->tx_bd_tail]; @@ -714,9 +720,15 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) cur_p->app0 |= 2; /* Tx Full Checksum Offload Enabled */ } - cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK; cur_p->phys = dma_map_single(ndev->dev.parent, skb->data, skb_headlen(skb), DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(ndev->dev.parent, cur_p->phys))) { + if (net_ratelimit()) + netdev_err(ndev, "TX DMA mapping error\n"); + ndev->stats.tx_dropped++; + return NETDEV_TX_OK; + } + cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK; for (ii = 0; ii < num_frag; ii++) { if (++lp->tx_bd_tail >= lp->tx_bd_num) @@ -727,6 +739,16 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) skb_frag_address(frag), skb_frag_size(frag), DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(ndev->dev.parent, cur_p->phys))) { + if (net_ratelimit()) + netdev_err(ndev, "TX DMA mapping error\n"); + ndev->stats.tx_dropped++; + axienet_free_tx_chain(ndev, orig_tail_ptr, ii + 1, + NULL); + lp->tx_bd_tail = orig_tail_ptr; + + return NETDEV_TX_OK; + } cur_p->cntrl = skb_frag_size(frag); } @@ -807,6 +829,13 @@ static void axienet_recv(struct net_device *ndev) cur_p->phys = dma_map_single(ndev->dev.parent, new_skb->data, lp->max_frm_size, DMA_FROM_DEVICE); + if (unlikely(dma_mapping_error(ndev->dev.parent, cur_p->phys))) { + if (net_ratelimit()) + netdev_err(ndev, "RX DMA mapping error\n"); + dev_kfree_skb(new_skb); + return; + } + cur_p->cntrl = lp->max_frm_size; cur_p->status = 0; cur_p->skb = new_skb;