From: Andy Spencer aspencer@spacex.com
commit d903ec77118c09f93a610b384d83a6df33a64fe6 upstream.
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 aspencer@spacex.com Signed-off-by: Jim Gruen jgruen@spacex.com Signed-off-by: David S. Miller davem@davemloft.net Cc: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/freescale/gianfar.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-)
--- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2936,29 +2936,17 @@ static bool gfar_add_rx_frag(struct gfar { 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 */ @@ -3071,6 +3059,9 @@ static void gfar_process_frame(struct ne 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);