[PATCH v2] net: mvneta: fix refilling for Rx DMA buffers
From: Simon Guinot <hidden>
Date: 2015-07-19 11:00:58
With the actual code, if a memory allocation error happens while
refilling a Rx descriptor, then the original Rx buffer is both passed
to the networking stack (in a SKB) and let in the Rx ring. This leads
to various kernel oops and crashes.
As a fix, this patch moves Rx descriptor refilling ahead of building
SKB with the associated Rx buffer. In case of a memory allocation
failure, data is dropped and the original DMA buffer is put back into
the Rx ring.
Signed-off-by: Simon Guinot <redacted>
Fixes: c5aff18204da ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Cc: <redacted> # v3.8+
Tested-by: Yoann Sculo <redacted>
---
drivers/net/ethernet/marvell/mvneta.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
Changes for v2:
- Update commit message.
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index ce5f7f9cff06..ac3da11e63a0 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c@@ -1455,7 +1455,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, struct mvneta_rx_queue *rxq) { struct net_device *dev = pp->dev; - int rx_done, rx_filled; + int rx_done; u32 rcvd_pkts = 0; u32 rcvd_bytes = 0;
@@ -1466,7 +1466,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, rx_todo = rx_done; rx_done = 0; - rx_filled = 0; /* Fairness NAPI loop */ while (rx_done < rx_todo) {
@@ -1477,7 +1476,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, int rx_bytes, err; rx_done++; - rx_filled++; rx_status = rx_desc->status; rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE); data = (unsigned char *)rx_desc->buf_cookie;
@@ -1517,6 +1515,14 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, continue; } + /* Refill processing */ + err = mvneta_rx_refill(pp, rx_desc); + if (err) { + netdev_err(dev, "Linux processing - Can't refill\n"); + rxq->missed++; + goto err_drop_frame; + } + skb = build_skb(data, pp->frag_size > PAGE_SIZE ? 0 : pp->frag_size); if (!skb) goto err_drop_frame;
@@ -1536,14 +1542,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, mvneta_rx_csum(pp, rx_status, skb); napi_gro_receive(&pp->napi, skb); - - /* Refill processing */ - err = mvneta_rx_refill(pp, rx_desc); - if (err) { - netdev_err(dev, "Linux processing - Can't refill\n"); - rxq->missed++; - rx_filled--; - } } if (rcvd_pkts) {
@@ -1556,7 +1554,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, } /* Update rxq management counters */ - mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_filled); + mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_done); return rx_done; }
--
2.1.4