Patch "net: pktgen: fix pkt_size" has been added to the 4.4-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2016-11-10 15:47:09
This is a note to let you know that I've just added the patch titled
net: pktgen: fix pkt_size
to the 4.4-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:
net-pktgen-fix-pkt_size.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.
From foo@baz Thu Nov 10 16:42:45 CET 2016
From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 30 Sep 2016 16:56:45 +0200
Subject: net: pktgen: fix pkt_size
From: Paolo Abeni <pabeni@redhat.com>
[ Upstream commit 63d75463c91a5b5be7c0aca11ceb45ea5a0ae81d ]
The commit 879c7220e828 ("net: pktgen: Observe needed_headroom
of the device") increased the 'pkt_overhead' field value by
LL_RESERVED_SPACE.
As a side effect the generated packet size, computed as:
/* Eth + IPh + UDPh + mpls */
datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 -
pkt_dev->pkt_overhead;
is decreased by the same value.
The above changed slightly the behavior of existing pktgen users,
and made the procfs interface somewhat inconsistent.
Fix it by restoring the previous pkt_overhead value and using
LL_RESERVED_SPACE as extralen in skb allocation.
Also, change pktgen_alloc_skb() to only partially reserve
the headroom to allow the caller to prefetch from ll header
start.
v1 -> v2:
- fixed some typos in the comments
Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device")
Suggested-by: Ben Greear <redacted>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/pktgen.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c@@ -2278,7 +2278,7 @@ static void spin(struct pktgen_dev *pkt_ static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev) { - pkt_dev->pkt_overhead = LL_RESERVED_SPACE(pkt_dev->odev); + pkt_dev->pkt_overhead = 0; pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32); pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev); pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev);
@@ -2769,13 +2769,13 @@ static void pktgen_finalize_skb(struct p } static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, - struct pktgen_dev *pkt_dev, - unsigned int extralen) + struct pktgen_dev *pkt_dev) { + unsigned int extralen = LL_RESERVED_SPACE(dev); struct sk_buff *skb = NULL; - unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen + - pkt_dev->pkt_overhead; + unsigned int size; + size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead; if (pkt_dev->flags & F_NODE) { int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id();
@@ -2788,8 +2788,9 @@ static struct sk_buff *pktgen_alloc_skb( skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT); } + /* the caller pre-fetches from skb->data and reserves for the mac hdr */ if (likely(skb)) - skb_reserve(skb, LL_RESERVED_SPACE(dev)); + skb_reserve(skb, extralen - 16); return skb; }
@@ -2822,16 +2823,14 @@ static struct sk_buff *fill_packet_ipv4( mod_cur_headers(pkt_dev); queue_map = pkt_dev->cur_queue_map; - datalen = (odev->hard_header_len + 16) & ~0xf; - - skb = pktgen_alloc_skb(odev, pkt_dev, datalen); + skb = pktgen_alloc_skb(odev, pkt_dev); if (!skb) { sprintf(pkt_dev->result, "No memory"); return NULL; } prefetchw(skb->data); - skb_reserve(skb, datalen); + skb_reserve(skb, 16); /* Reserve for ethernet and IP header */ eth = (__u8 *) skb_push(skb, 14);
@@ -2951,7 +2950,7 @@ static struct sk_buff *fill_packet_ipv6( mod_cur_headers(pkt_dev); queue_map = pkt_dev->cur_queue_map; - skb = pktgen_alloc_skb(odev, pkt_dev, 16); + skb = pktgen_alloc_skb(odev, pkt_dev); if (!skb) { sprintf(pkt_dev->result, "No memory"); return NULL;
Patches currently in stable-queue which might be from pabeni@redhat.com are queue-4.4/net-pktgen-fix-pkt_size.patch