Messages in this thread | | | Subject | Re: [PATCH] net: fec: fix regression on i.MX28 introduced by rx_copybreak support | From | Eric Dumazet <> | Date | Tue, 07 Oct 2014 07:27:14 -0700 |
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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 <LW@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 ?
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