diff mbox

forcedeth skb_gso_segment warning

Message ID 20090629040330.GA2981@gondor.apana.org.au
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Herbert Xu June 29, 2009, 4:03 a.m. UTC 
On Tue, Jun 09, 2009 at 11:19:23AM +0200, Johannes Berg wrote:
> Happened a number of times:
> 
> Jun  8 18:56:25 johannes kernel: [33987.849090] ------------[ cut here ]------------
> Jun  8 18:56:25 johannes kernel: [33987.849106] WARNING: at /home/johannes/sys/wireless-testing/net/core/dev.c:1560 skb_gso_segment+0x233/0x2e0()
> Jun  8 18:56:25 johannes kernel: [33987.849110] Hardware name: MacBook5,1
> Jun  8 18:56:25 johannes kernel: [33987.849114] forcedeth: caps=(0x10823, 0x19082b) len=65212 data_len=63712 ip_summed=0

Thank you!

This was the clue I needed.  The fact that the packet is TSO and
not completely non-linear.

tcp: Stop non-TSO packets morphing into TSO

If a socket starts out on a non-TSO route, and then switches to
a TSO route, then the tail on the tx queue can morph into a TSO
packet, causing mischief because the rest of the stack does not
expect a partially linear TSO packet.

This patch fixes this by ensuring that skb->ip_summed is set to
CHECKSUM_PARTIAL before declaring a packet as TSO.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>


Thanks,

Comments

David Miller June 30, 2009, 2:43 a.m. UTC | #1 
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Mon, 29 Jun 2009 12:03:30 +0800

> tcp: Stop non-TSO packets morphing into TSO
> 
> If a socket starts out on a non-TSO route, and then switches to
> a TSO route, then the tail on the tx queue can morph into a TSO
> packet, causing mischief because the rest of the stack does not
> expect a partially linear TSO packet.
> 
> This patch fixes this by ensuring that skb->ip_summed is set to
> CHECKSUM_PARTIAL before declaring a packet as TSO.
> 
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Applied.
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diff mbox

Patch

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 416fc4c..5bdf08d 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -725,7 +725,8 @@  static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
 static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb,
 				 unsigned int mss_now)
 {
-	if (skb->len <= mss_now || !sk_can_gso(sk)) {
+	if (skb->len <= mss_now || !sk_can_gso(sk) ||
+	    skb->ip_summed == CHECKSUM_NONE) {
 		/* Avoid the costly divide in the normal
 		 * non-TSO case.
 		 */