Previously, buffer descriptors containing only the frame check sequence
(FCS) were skipped and not added to the skb. However, the page reference
count was still incremented, leading to a memory leak.
Fixing this inside gfar_add_rx_frag() is difficult due to reserved
memory handling and page reuse. Instead, move the FCS handling to
gfar_process_frame() and trim off the FCS before passing the skb up the
networking stack.
Signed-off-by: Andy Spencer <aspen...@spacex.com>
Signed-off-by: Jim Gruen <jgr...@spacex.com>
---
drivers/net/ethernet/freescale/gianfar.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)
diff --git a/drivers/net/ethernet/freescale/gianfar.c
b/drivers/net/ethernet/freescale/gianfar.c
index 3bdeb29..f5c87bd3 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -2934,29 +2934,17 @@ static bool gfar_add_rx_frag(struct gfar_rx_buff *rxb,
u32 lstatus,
{
int size = lstatus & BD_LENGTH_MASK;
struct page *page = rxb->page;
- bool last = !!(lstatus & BD_LFLAG(RXBD_LAST));
-
- /* Remove the FCS from the packet length */
- if (last)
- size -= ETH_FCS_LEN;
if (likely(first)) {
skb_put(skb, size);
} else {
/* the last fragments' length contains the full frame length */
- if (last)
+ if (lstatus & BD_LFLAG(RXBD_LAST))
size -= skb->len;
- /* Add the last fragment if it contains something other than
- * the FCS, otherwise drop it and trim off any part of the FCS
- * that was already received.
- */
- if (size > 0)
- skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
- rxb->page_offset + RXBUF_ALIGNMENT,
- size, GFAR_RXB_TRUESIZE);
- else if (size < 0)
- pskb_trim(skb, skb->len + size);
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
+ rxb->page_offset + RXBUF_ALIGNMENT,
+ size, GFAR_RXB_TRUESIZE);
}
/* try reuse page */
@@ -3069,6 +3057,9 @@ static void gfar_process_frame(struct net_device *ndev,
struct sk_buff *skb)
if (priv->padding)
skb_pull(skb, priv->padding);
+ /* Trim off the FCS */
+ pskb_trim(skb, skb->len - ETH_FCS_LEN);
+
if (ndev->features & NETIF_F_RXCSUM)
gfar_rx_checksum(skb, fcb);
--
2.7.4
