netdev - [PATCH] sky2: turn off Rx checksum on bad hardware

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20070308124230.208b7c9a@freekitty>
Date:	Thu, 8 Mar 2007 12:42:30 -0800
From:	Stephen Hemminger <shemminger@...ux-foundation.org>
To:	Jeff Garzik <jgarzik@...ox.com>
Cc:	netdev@...r.kernel.org
Subject: [PATCH] sky2: turn off Rx checksum on bad hardware

On Yukon FE, occasional hardware receive checksum errors are seen.
An early indication of the problem is single bit differences in the two
checksum engines.  Use this as a detection mechanism to turn off Rx
checksumming.

Signed-off-by: Stephen Hemminger <shemminger@...ux-foundation.org>

---
 drivers/net/sky2.c |   24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

--- sky2-dev.orig/drivers/net/sky2.c	2007-03-05 16:49:31.000000000 -0800
+++ sky2-dev/drivers/net/sky2.c	2007-03-05 16:49:45.000000000 -0800
@@ -2165,9 +2165,27 @@
 			/* fall through */
 #endif
 		case OP_RXCHKS:
-			skb = sky2->rx_ring[sky2->rx_next].skb;
-			skb->ip_summed = CHECKSUM_COMPLETE;
-			skb->csum = status & 0xffff;
+			if (!sky2->rx_csum)
+				break;
+
+			/* Both checksum counters are programmed to start at
+			 * the same offset, so unless there is a problem they
+			 * should match. This failure is an early indication that
+			 * hardware receive checksumming won't work.
+			 */
+			if (likely(status >> 16 == (status & 0xffff))) {
+				skb = sky2->rx_ring[sky2->rx_next].skb;
+				skb->ip_summed = CHECKSUM_COMPLETE;
+				skb->csum = status & 0xffff;
+			} else {
+				printk(KERN_NOTICE PFX "%s: hardware receive "
+				       "checksum problem (status = %#x)\n",
+				       dev->name, status);
+				sky2->rx_csum = 0;
+				sky2_write32(sky2->hw,
+					     Q_ADDR(rxqaddr[le->link], Q_CSR),
+					     BMU_DIS_RX_CHKSUM);
+			}
 			break;
 
 		case OP_TXINDEXLE:
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html