Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753852AbaJGNTv (ORCPT ); Tue, 7 Oct 2014 09:19:51 -0400 Received: from mail.karo-electronics.de ([81.173.242.67]:49859 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752462AbaJGNTt (ORCPT ); Tue, 7 Oct 2014 09:19:49 -0400 From: =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= To: netdev@vger.kernel.org Cc: "David S. Miller" , Russell King , Frank Li , Fabio Estevam , linux-kernel@vger.kernel.org, =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= Subject: [PATCH] net: fec: fix regression on i.MX28 introduced by rx_copybreak support Date: Tue, 7 Oct 2014 15:19:37 +0200 Message-Id: <1412687977-11742-1-git-send-email-LW@KARO-electronics.de> X-Mailer: git-send-email 1.7.10.4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 1b7bde6d659d ("net: fec: implement rx_copybreak to improve rx performance") introduced a regression for i.MX28. The swap_buffer() function doing the endian conversion of the received data on i.MX28 may access memory beyond the actual packet size in the DMA buffer. fec_enet_copybreak() does not copy those bytes, so that the last bytes of a packet may be filled with invalid data after swapping. This will likely lead to checksum errors on received packets. E.g. when trying to mount an NFS rootfs: UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36 Do the byte swapping and copying to the new skb in one go if necessary. Signed-off-by: Lothar Waßmann --- drivers/net/ethernet/freescale/fec_main.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 87975b5..eaaebad 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -339,6 +339,18 @@ static void *swap_buffer(void *bufaddr, int len) return bufaddr; } +static void *swap_buffer2(void *dst_buf, void *src_buf, int len) +{ + int i; + unsigned int *src = src_buf; + unsigned int *dst = dst_buf; + + for (i = 0; i < DIV_ROUND_UP(len, 4); i++, src++, dst++) + *dst = cpu_to_be32(*src); + + return dst_buf; +} + static void fec_dump(struct net_device *ndev) { struct fec_enet_private *fep = netdev_priv(ndev); @@ -1348,7 +1360,7 @@ fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff } static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb, - struct bufdesc *bdp, u32 length) + struct bufdesc *bdp, u32 length, int swap) { struct fec_enet_private *fep = netdev_priv(ndev); struct sk_buff *new_skb; @@ -1363,7 +1375,10 @@ static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb, dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr, FEC_ENET_RX_FRSIZE - fep->rx_align, DMA_FROM_DEVICE); - memcpy(new_skb->data, (*skb)->data, length); + if (!swap) + memcpy(new_skb->data, (*skb)->data, length); + else + swap_buffer2(new_skb->data, (*skb)->data, length); *skb = new_skb; return true; @@ -1393,6 +1408,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) u16 vlan_tag; int index = 0; bool is_copybreak; + bool need_swap = id_entry->driver_data & FEC_QUIRK_SWAP_FRAME; #ifdef CONFIG_M532x flush_cache_all(); @@ -1456,7 +1472,8 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) * include that when passing upstream as it messes up * bridging applications. */ - is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4); + is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4, + need_swap); if (!is_copybreak) { skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE); if (unlikely(!skb_new)) { @@ -1471,7 +1488,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) prefetch(skb->data - NET_IP_ALIGN); skb_put(skb, pkt_len - 4); data = skb->data; - if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME) + if (!is_copybreak && need_swap) swap_buffer(data, pkt_len); /* Extract the enhanced buffer descriptor */ -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/