On Tue, 2014-10-07 at 15:19 +0200, Lothar Waßmann wrote:
> 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 <l...@karo-electronics.de>
> ---
> 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);
No need for the DIV :
for (i = 0; i < len; i += sizeof(*dst), src++, dst++)
*dst = cpu_to_be32(*src);
Also are you sure both src/dst are aligned to word boundaries, or is
this architecture OK with possible misalignment ?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
