lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 8 Oct 2014 07:01:47 +0200 From: Lothar Waßmann <LW@...O-electronics.de> To: David Laight <David.Laight@...LAB.COM> Cc: 'Eric Dumazet' <eric.dumazet@...il.com>, "netdev@...r.kernel.org" <netdev@...r.kernel.org>, "David S. Miller" <davem@...emloft.net>, Russell King <rmk+kernel@....linux.org.uk>, Frank Li <Frank.Li@...escale.com>, Fabio Estevam <fabio.estevam@...escale.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH] net: fec: fix regression on i.MX28 introduced by rx_copybreak support Hi, David Laight wrote: > From: Eric Dumazet > > On Tue, 2014-10-07 at 15:19 +0200, Lothar Wamann 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 Wamann <LW@...O-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 ? > > I wondered about that as well. > I wouldn't have expected ppc to support misaligned transfers, and you'd also > want to make sure that cpu_to_be(*src) was using a byte-swapping instruction. > Hmmm... cpu_to_be() doesn't sound like the right 'swap' macro name. > ??? So what is cpu_to_be32() then? The new swap function is an exact copy of the original one already in use except for the fact that it uses distinct source and destination buffers. Lothar Waßmann -- ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstraße 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Geschäftsführer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info@...o-electronics.de ___________________________________________________________ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists