<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/net, branch v3.3.5</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>mac80211: fix AP mode EAP tx for VLAN stations</title>
<updated>2012-05-07T15:53:37+00:00</updated>
<author>
<name>Felix Fietkau</name>
<email>nbd@openwrt.org</email>
</author>
<published>2012-04-29T13:44:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a8abc1d0160641c79fbaafeedb57506beb3780e4'/>
<id>a8abc1d0160641c79fbaafeedb57506beb3780e4</id>
<content type='text'>
commit 66f2c99af3d6f2d0aa1120884cf1c60613ef61c0 upstream.

EAP frames for stations in an AP VLAN are sent on the main AP interface
to avoid race conditions wrt. moving stations.
For that to work properly, sta_info_get_bss must be used instead of
sta_info_get when sending EAP packets.
Previously this was only done for cooked monitor injected packets, so
this patch adds a check for tx-&gt;skb-&gt;protocol to the same place.

Signed-off-by: Felix Fietkau &lt;nbd@openwrt.org&gt;
Signed-off-by: John W. Linville &lt;linville@tuxdriver.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 66f2c99af3d6f2d0aa1120884cf1c60613ef61c0 upstream.

EAP frames for stations in an AP VLAN are sent on the main AP interface
to avoid race conditions wrt. moving stations.
For that to work properly, sta_info_get_bss must be used instead of
sta_info_get when sending EAP packets.
Previously this was only done for cooked monitor injected packets, so
this patch adds a check for tx-&gt;skb-&gt;protocol to the same place.

Signed-off-by: Felix Fietkau &lt;nbd@openwrt.org&gt;
Signed-off-by: John W. Linville &lt;linville@tuxdriver.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>nl80211: ensure interface is up in various APIs</title>
<updated>2012-05-07T15:53:22+00:00</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2012-04-02T08:51:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c5ed4ce988daccdb0f08c28760475d6b13722498'/>
<id>c5ed4ce988daccdb0f08c28760475d6b13722498</id>
<content type='text'>
commit 2b5f8b0b44e17e625cfba1e7b88db44f4dcc0441 upstream.
[backported by Ben Greear]

The nl80211 handling code should ensure as much as
it can that the interface is in a valid state, it
can certainly ensure the interface is running.

Not doing so can cause calls through mac80211 into
the driver that result in warnings and unspecified
behaviour in the driver.

Reported-by: Ben Greear &lt;greearb@candelatech.com&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: John W. Linville &lt;linville@tuxdriver.com&gt;
Signed-off-by: Ben Greear &lt;greearb@candelatech.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2b5f8b0b44e17e625cfba1e7b88db44f4dcc0441 upstream.
[backported by Ben Greear]

The nl80211 handling code should ensure as much as
it can that the interface is in a valid state, it
can certainly ensure the interface is running.

Not doing so can cause calls through mac80211 into
the driver that result in warnings and unspecified
behaviour in the driver.

Reported-by: Ben Greear &lt;greearb@candelatech.com&gt;
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: John W. Linville &lt;linville@tuxdriver.com&gt;
Signed-off-by: Ben Greear &lt;greearb@candelatech.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: avoid order-1 allocations on wifi and tx path</title>
<updated>2012-04-27T17:17:06+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>eric.dumazet@gmail.com</email>
</author>
<published>2012-04-25T03:01:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0df29c4a2857ed43ff23689423144aaf4f4101bc'/>
<id>0df29c4a2857ed43ff23689423144aaf4f4101bc</id>
<content type='text'>
[ This combines upstream commit
  a21d45726acacc963d8baddf74607d9b74e2b723 and the follow-on bug fix
  commit a21d45726acacc963d8baddf74607d9b74e2b723 ]

Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

After investigation, it turns out TCP uses sk_stream_alloc_skb() and
used as a convention skb_tailroom(skb) to know how many bytes of data
payload could be put in this skb (for non SG capable devices)

Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER +
sizeof(struct skb_shared_info) being above 2048)

Later, mac80211 layer need to add some bytes at the tail of skb
(IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is
available has to call pskb_expand_head() and request order-1
allocations.

This patch changes sk_stream_alloc_skb() so that only
sk-&gt;sk_prot-&gt;max_header bytes of headroom are reserved, and use a new
skb field, avail_size to hold the data payload limit.

This way, order-0 allocations done by TCP stack can leave more than 2 KB
of tailroom and no more allocation is performed in mac80211 layer (or
any layer needing some tailroom)

avail_size is unioned with mark/dropcount, since mark will be set later
in IP stack for output packets. Therefore, skb size is unchanged.

Reported-by: Marc MERLIN &lt;marc@merlins.org&gt;
Tested-by: Marc MERLIN &lt;marc@merlins.org&gt;
Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ This combines upstream commit
  a21d45726acacc963d8baddf74607d9b74e2b723 and the follow-on bug fix
  commit a21d45726acacc963d8baddf74607d9b74e2b723 ]

Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

After investigation, it turns out TCP uses sk_stream_alloc_skb() and
used as a convention skb_tailroom(skb) to know how many bytes of data
payload could be put in this skb (for non SG capable devices)

Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER +
sizeof(struct skb_shared_info) being above 2048)

Later, mac80211 layer need to add some bytes at the tail of skb
(IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is
available has to call pskb_expand_head() and request order-1
allocations.

This patch changes sk_stream_alloc_skb() so that only
sk-&gt;sk_prot-&gt;max_header bytes of headroom are reserved, and use a new
skb field, avail_size to hold the data payload limit.

This way, order-0 allocations done by TCP stack can leave more than 2 KB
of tailroom and no more allocation is performed in mac80211 layer (or
any layer needing some tailroom)

avail_size is unioned with mark/dropcount, since mark will be set later
in IP stack for output packets. Therefore, skb size is unchanged.

Reported-by: Marc MERLIN &lt;marc@merlins.org&gt;
Tested-by: Marc MERLIN &lt;marc@merlins.org&gt;
Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: allow pskb_expand_head() to get maximum tailroom</title>
<updated>2012-04-27T17:17:06+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>eric.dumazet@gmail.com</email>
</author>
<published>2012-04-10T20:08:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1cf9d571c6e48f15608203fc76fa29c617459e0c'/>
<id>1cf9d571c6e48f15608203fc76fa29c617459e0c</id>
<content type='text'>
[ Upstream commit 87151b8689d890dfb495081f7be9b9e257f7a2df ]

Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

Turns out part of the problem comes from pskb_expand_head() not using
ksize() to get exact head size given by kmalloc(). Doing the same thing
than __alloc_skb() allows more tailroom in skb and can prevent future
reallocations.

As a bonus, struct skb_shared_info becomes cache line aligned.

Reported-by: Marc MERLIN &lt;marc@merlins.org&gt;
Tested-by: Marc MERLIN &lt;marc@merlins.org&gt;
Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 87151b8689d890dfb495081f7be9b9e257f7a2df ]

Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

Turns out part of the problem comes from pskb_expand_head() not using
ksize() to get exact head size given by kmalloc(). Doing the same thing
than __alloc_skb() allows more tailroom in skb and can prevent future
reallocations.

As a bonus, struct skb_shared_info becomes cache line aligned.

Reported-by: Marc MERLIN &lt;marc@merlins.org&gt;
Tested-by: Marc MERLIN &lt;marc@merlins.org&gt;
Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: fix TCP_MAXSEG for established IPv6 passive sockets</title>
<updated>2012-04-27T17:17:05+00:00</updated>
<author>
<name>Neal Cardwell</name>
<email>ncardwell@google.com</email>
</author>
<published>2012-04-22T09:45:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=069d2955aa39b11764025031235ec3d7d215ce84'/>
<id>069d2955aa39b11764025031235ec3d7d215ce84</id>
<content type='text'>
[ Upstream commit d135c522f1234f62e81be29cebdf59e9955139ad ]

Commit f5fff5d forgot to fix TCP_MAXSEG behavior IPv6 sockets, so IPv6
TCP server sockets that used TCP_MAXSEG would find that the advmss of
child sockets would be incorrect. This commit mirrors the advmss logic
from tcp_v4_syn_recv_sock in tcp_v6_syn_recv_sock. Eventually this
logic should probably be shared between IPv4 and IPv6, but this at
least fixes this issue.

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d135c522f1234f62e81be29cebdf59e9955139ad ]

Commit f5fff5d forgot to fix TCP_MAXSEG behavior IPv6 sockets, so IPv6
TCP server sockets that used TCP_MAXSEG would find that the advmss of
child sockets would be incorrect. This commit mirrors the advmss logic
from tcp_v4_syn_recv_sock in tcp_v6_syn_recv_sock. Eventually this
logic should probably be shared between IPv4 and IPv6, but this at
least fixes this issue.

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net ax25: Reorder ax25_exit to remove races.</title>
<updated>2012-04-27T17:17:05+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2012-04-18T16:11:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0bcc60d6527fde19ce2ccff7bc3eaba5209a6693'/>
<id>0bcc60d6527fde19ce2ccff7bc3eaba5209a6693</id>
<content type='text'>
[ Upstream commit 3adadc08cc1e2cbcc15a640d639297ef5fcb17f5 ]

While reviewing the sysctl code in ax25 I spotted races in ax25_exit
where it is possible to receive notifications and packets after already
freeing up some of the data structures needed to process those
notifications and updates.

Call unregister_netdevice_notifier early so that the rest of the cleanup
code does not need to deal with network devices.  This takes advantage
of my recent enhancement to unregister_netdevice_notifier to send
unregister notifications of all network devices that are current
registered.

Move the unregistration for packet types, socket types and protocol
types before we cleanup any of the ax25 data structures to remove the
possibilities of other races.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3adadc08cc1e2cbcc15a640d639297ef5fcb17f5 ]

While reviewing the sysctl code in ax25 I spotted races in ax25_exit
where it is possible to receive notifications and packets after already
freeing up some of the data structures needed to process those
notifications and updates.

Call unregister_netdevice_notifier early so that the rest of the cleanup
code does not need to deal with network devices.  This takes advantage
of my recent enhancement to unregister_netdevice_notifier to send
unregister notifications of all network devices that are current
registered.

Move the unregistration for packet types, socket types and protocol
types before we cleanup any of the ax25 data structures to remove the
possibilities of other races.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netns: do not leak net_generic data on failed init</title>
<updated>2012-04-27T17:17:05+00:00</updated>
<author>
<name>Julian Anastasov</name>
<email>ja@ssi.bg</email>
</author>
<published>2012-04-16T04:43:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e6f8c8491515dcaa8686d7e6b805edd4aba281d8'/>
<id>e6f8c8491515dcaa8686d7e6b805edd4aba281d8</id>
<content type='text'>
[ Upstream commit b922934d017f1cc831b017913ed7d1a56c558b43 ]

ops_init should free the net_generic data on
init failure and __register_pernet_operations should not
call ops_free when NET_NS is not enabled.

Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Reviewed-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b922934d017f1cc831b017913ed7d1a56c558b43 ]

ops_init should free the net_generic data on
init failure and __register_pernet_operations should not
call ops_free when NET_NS is not enabled.

Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Reviewed-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: fix tcp_grow_window() for large incoming frames</title>
<updated>2012-04-27T17:17:05+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2012-04-16T23:28:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=07b267776c0746c14b28d931a623fb59736a672a'/>
<id>07b267776c0746c14b28d931a623fb59736a672a</id>
<content type='text'>
[ Upstream commit 4d846f02392a710f9604892ac3329e628e60a230 ]

tcp_grow_window() has to grow rcv_ssthresh up to window_clamp, allowing
sender to increase its window.

tcp_grow_window() still assumes a tcp frame is under MSS, but its no
longer true with LRO/GRO.

This patch fixes one of the performance issue we noticed with GRO on.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Tom Herbert &lt;therbert@google.com&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4d846f02392a710f9604892ac3329e628e60a230 ]

tcp_grow_window() has to grow rcv_ssthresh up to window_clamp, allowing
sender to increase its window.

tcp_grow_window() still assumes a tcp frame is under MSS, but its no
longer true with LRO/GRO.

This patch fixes one of the performance issue we noticed with GRO on.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Tom Herbert &lt;therbert@google.com&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net_sched: gred: Fix oops in gred_dump() in WRED mode</title>
<updated>2012-04-27T17:17:05+00:00</updated>
<author>
<name>David Ward</name>
<email>david.ward@ll.mit.edu</email>
</author>
<published>2012-04-15T12:31:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c2b606aa4f25a3cd94a1eb061c814e2acf8134c9'/>
<id>c2b606aa4f25a3cd94a1eb061c814e2acf8134c9</id>
<content type='text'>
[ Upstream commit 244b65dbfede788f2fa3fe2463c44d0809e97c6b ]

A parameter set exists for WRED mode, called wred_set, to hold the same
values for qavg and qidlestart across all VQs. The WRED mode values had
been previously held in the VQ for the default DP. After these values
were moved to wred_set, the VQ for the default DP was no longer created
automatically (so that it could be omitted on purpose, to have packets
in the default DP enqueued directly to the device without using RED).

However, gred_dump() was overlooked during that change; in WRED mode it
still reads qavg/qidlestart from the VQ for the default DP, which might
not even exist. As a result, this command sequence will cause an oops:

tc qdisc add dev $DEV handle $HANDLE parent $PARENT gred setup \
    DPs 3 default 2 grio
tc qdisc change dev $DEV handle $HANDLE gred DP 0 prio 8 $RED_OPTIONS
tc qdisc change dev $DEV handle $HANDLE gred DP 1 prio 8 $RED_OPTIONS

This fixes gred_dump() in WRED mode to use the values held in wred_set.

Signed-off-by: David Ward &lt;david.ward@ll.mit.edu&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 244b65dbfede788f2fa3fe2463c44d0809e97c6b ]

A parameter set exists for WRED mode, called wred_set, to hold the same
values for qavg and qidlestart across all VQs. The WRED mode values had
been previously held in the VQ for the default DP. After these values
were moved to wred_set, the VQ for the default DP was no longer created
automatically (so that it could be omitted on purpose, to have packets
in the default DP enqueued directly to the device without using RED).

However, gred_dump() was overlooked during that change; in WRED mode it
still reads qavg/qidlestart from the VQ for the default DP, which might
not even exist. As a result, this command sequence will cause an oops:

tc qdisc add dev $DEV handle $HANDLE parent $PARENT gred setup \
    DPs 3 default 2 grio
tc qdisc change dev $DEV handle $HANDLE gred DP 0 prio 8 $RED_OPTIONS
tc qdisc change dev $DEV handle $HANDLE gred DP 1 prio 8 $RED_OPTIONS

This fixes gred_dump() in WRED mode to use the values held in wred_set.

Signed-off-by: David Ward &lt;david.ward@ll.mit.edu&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: fix tcp_rcv_rtt_update() use of an unscaled RTT sample</title>
<updated>2012-04-27T17:17:04+00:00</updated>
<author>
<name>Neal Cardwell</name>
<email>ncardwell@google.com</email>
</author>
<published>2012-04-10T07:59:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8607ccff19e16b51feab33664425e5984f751074'/>
<id>8607ccff19e16b51feab33664425e5984f751074</id>
<content type='text'>
[ Upstream commit 18a223e0b9ec8979320ba364b47c9772391d6d05 ]

Fix a code path in tcp_rcv_rtt_update() that was comparing scaled and
unscaled RTT samples.

The intent in the code was to only use the 'm' measurement if it was a
new minimum.  However, since 'm' had not yet been shifted left 3 bits
but 'new_sample' had, this comparison would nearly always succeed,
leading us to erroneously set our receive-side RTT estimate to the 'm'
sample when that sample could be nearly 8x too high to use.

The overall effect is to often cause the receive-side RTT estimate to
be significantly too large (up to 40% too large for brief periods in
my tests).

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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[ Upstream commit 18a223e0b9ec8979320ba364b47c9772391d6d05 ]

Fix a code path in tcp_rcv_rtt_update() that was comparing scaled and
unscaled RTT samples.

The intent in the code was to only use the 'm' measurement if it was a
new minimum.  However, since 'm' had not yet been shifted left 3 bits
but 'new_sample' had, this comparison would nearly always succeed,
leading us to erroneously set our receive-side RTT estimate to the 'm'
sample when that sample could be nearly 8x too high to use.

The overall effect is to often cause the receive-side RTT estimate to
be significantly too large (up to 40% too large for brief periods in
my tests).

Signed-off-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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