This is a note to let you know that I've just added the patch titled
tcp: gso: fix truesize tracking
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-gso-fix-truesize-tracking.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4db90cba8f8c482183e9d4c6da83ecd36cb8ef17 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri, 25 Oct 2013 17:26:17 -0700
Subject: tcp: gso: fix truesize tracking
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 0d08c42cf9a71530fef5ebcfe368f38f2dd0476f ]
commit 6ff50cd55545 ("tcp: gso: do not generate out of order packets")
had an heuristic that can trigger a warning in skb_try_coalesce(),
because skb->truesize of the gso segments were exactly set to mss.
This breaks the requirement that
skb->truesize >= skb->len + truesizeof(struct sk_buff);
It can trivially be reproduced by :
ifconfig lo mtu 1500
ethtool -K lo tso off
netperf
As the skbs are looped into the TCP networking stack, skb_try_coalesce()
warns us of these skb under-estimating their truesize.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/tcp_offload.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -18,6 +18,7 @@ struct sk_buff *tcp_tso_segment(struct s
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
+ unsigned int sum_truesize = 0;
struct tcphdr *th;
unsigned int thlen;
unsigned int seq;
@@ -102,13 +103,7 @@ struct sk_buff *tcp_tso_segment(struct s
if (copy_destructor) {
skb->destructor = gso_skb->destructor;
skb->sk = gso_skb->sk;
- /* {tcp|sock}_wfree() use exact truesize accounting :
- * sum(skb->truesize) MUST be exactly be gso_skb->truesize
- * So we account mss bytes of 'true size' for each segment.
- * The last segment will contain the remaining.
- */
- skb->truesize = mss;
- gso_skb->truesize -= mss;
+ sum_truesize += skb->truesize;
}
skb = skb->next;
th = tcp_hdr(skb);
@@ -125,7 +120,9 @@ struct sk_buff *tcp_tso_segment(struct s
if (copy_destructor) {
swap(gso_skb->sk, skb->sk);
swap(gso_skb->destructor, skb->destructor);
- swap(gso_skb->truesize, skb->truesize);
+ sum_truesize += skb->truesize;
+ atomic_add(sum_truesize - gso_skb->truesize,
+ &skb->sk->sk_wmem_alloc);
}
delta = htonl(oldlen + (skb_tail_pointer(skb) -
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-3.12/ipv6-ip6_dst_check-needs-to-check-for-expired-dst_entries.patch
queue-3.12/ipv6-reset-dst.expires-value-when-clearing-expire-flag.patch
queue-3.12/tcp-only-take-rtt-from-timestamps-if-new-data-is-acked.patch
queue-3.12/tcp-gso-fix-truesize-tracking.patch
queue-3.12/net-flow_dissector-fail-on-evil-iph-ihl.patch
queue-3.12/tcp-fix-synack-rtt-estimation-in-fast-open.patch
queue-3.12/tcp-do-not-rearm-rto-when-future-data-are-sacked.patch
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