linux-toradex.git/drivers/net/loopback.c, branch v3.14.57

drivers/net: delete non-required instances of include

2014-01-16T19:53:26+00:00

None of these files are actually using any __init type directives
and hence don't need to include .   Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

This covers everything under drivers/net except for wireless, which
has been submitted separately.

Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller

net: Explicitly initialize u64_stats_sync structures for lockdep

2013-11-06T11:40:25+00:00

In order to enable lockdep on seqcount/seqlock structures, we
must explicitly initialize any locks.

The u64_stats_sync structure, uses a seqcount, and thus we need
to introduce a u64_stats_init() function and use it to initialize
the structure.

This unfortunately adds a lot of fairly trivial initialization code
to a number of drivers. But the benefit of ensuring correctness makes
this worth while.

Because these changes are required for lockdep to be enabled, and the
changes are quite trivial, I've not yet split this patch out into 30-some
separate patches, as I figured it would be better to get the various
maintainers thoughts on how to best merge this change along with
the seqcount lockdep enablement.

Feedback would be appreciated!

Signed-off-by: John Stultz 
Acked-by: Julian Anastasov 
Signed-off-by: Peter Zijlstra 
Cc: Alexey Kuznetsov 
Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Hideaki YOSHIFUJI 
Cc: James Morris 
Cc: Jesse Gross 
Cc: Mathieu Desnoyers 
Cc: "Michael S. Tsirkin" 
Cc: Mirko Lindner 
Cc: Patrick McHardy 
Cc: Roger Luethi 
Cc: Rusty Russell 
Cc: Simon Horman 
Cc: Stephen Hemminger 
Cc: Steven Rostedt 
Cc: Thomas Petazzoni 
Cc: Wensong Zhang 
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar

net loopback: Set loopback_dev to NULL when freed

2013-09-17T23:05:13+00:00

It has recently turned up that we have a number of long standing bugs
in the network stack cleanup code with use of the loopback device
after it has been freed that have not turned up because in most cases
the storage allocated to the loopback device is not reused, when those
accesses happen.

Set looback_dev to NULL to trigger oopses instead of silent data corrupt
when we hit this class of bug.

Signed-off-by: "Eric W. Biederman" 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: loopback: fix a dst refcounting issue

2013-01-27T06:30:35+00:00

Ben Greear reported crashes in ip_rcv_finish() on a stress
test involving many macvlans.

We tracked the bug to a dst use after free. ip_rcv_finish()
was calling dst->input() and got garbage for dst->input value.

It appears the bug is in loopback driver, lacking
a skb_dst_force() before calling netif_rx().

As a result, a non refcounted dst, normally protected by a
RCU read_lock section, was escaping this section and could
be freed before the packet being processed.

  [] loopback_xmit+0x64/0x83
  [] dev_hard_start_xmit+0x26c/0x35e
  [] dev_queue_xmit+0x2c4/0x37c
  [] ? dev_hard_start_xmit+0x35e/0x35e
  [] ? eth_header+0x28/0xb6
  [] neigh_resolve_output+0x176/0x1a7
  [] ip_finish_output2+0x297/0x30d
  [] ? ip_finish_output2+0x137/0x30d
  [] ip_finish_output+0x63/0x68
  [] ip_output+0x61/0x67
  [] dst_output+0x17/0x1b
  [] ip_local_out+0x1e/0x23
  [] ip_queue_xmit+0x315/0x353
  [] ? ip_send_unicast_reply+0x2cc/0x2cc
  [] tcp_transmit_skb+0x7ca/0x80b
  [] tcp_connect+0x53c/0x587
  [] ? getnstimeofday+0x44/0x7d
  [] ? ktime_get_real+0x11/0x3e
  [] tcp_v4_connect+0x3c2/0x431
  [] __inet_stream_connect+0x84/0x287
  [] ? inet_stream_connect+0x22/0x49
  [] ? _local_bh_enable_ip+0x84/0x9f
  [] ? local_bh_enable+0xd/0x11
  [] ? lock_sock_nested+0x6e/0x79
  [] ? inet_stream_connect+0x22/0x49
  [] inet_stream_connect+0x33/0x49
  [] sys_connect+0x75/0x98

This bug was introduced in linux-2.6.35, in commit
7fee226ad2397b (net: add a noref bit on skb dst)

skb_dst_force() is enforced in dev_queue_xmit() for devices having a
qdisc.

Reported-by: Ben Greear 
Signed-off-by: Eric Dumazet 
Tested-by: Ben Greear 
Signed-off-by: David S. Miller

net: loopback: set default mtu to 64K

2012-09-24T20:23:53+00:00

loopback current mtu of 16436 bytes allows no more than 3 MSS TCP
segments per frame, or 48 Kbytes. Changing mtu to 64K allows TCP
stack to build large frames and significantly reduces stack overhead.

Performance boost on bulk TCP transferts can be up to 30 %, partly
because we now have one ACK message for two 64KB segments, and a lower
probability of hitting /proc/sys/net/ipv4/tcp_reordering default limit.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: Loopback ifindex is constant now

2012-08-09T23:18:07+00:00

As pointed out, there are places, that access net->loopback_dev->ifindex
and after ifindex generation is made per-net this value becomes constant
equals 1. So go ahead and introduce the LOOPBACK_IFINDEX constant and use
it where appropriate.

Signed-off-by: Pavel Emelyanov 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: fix race condition in several drivers when reading stats

2012-07-22T19:12:32+00:00

Fix race condition in several network drivers when reading stats on 32bit
UP architectures.  These drivers update their stats in a BH context and
therefore should use u64_stats_fetch_begin_bh/u64_stats_fetch_retry_bh
instead of u64_stats_fetch_begin/u64_stats_fetch_retry when reading the
stats.

Signed-off-by: Kevin Groeneveld 
Signed-off-by: David S. Miller

Remove all #inclusions of asm/system.h

2012-03-28T17:30:03+00:00

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *`

Signed-off-by: David Howells

net: remove NETIF_F_NO_CSUM feature bit

2011-11-16T22:43:12+00:00

Only distinct use is checking if NETIF_F_NOCACHE_COPY should be
enabled by default. The check heuristics is altered a bit here,
so it hits other people than before. The default shouldn't be
trusted for performance-critical cases anyway.

For all other uses NETIF_F_NO_CSUM is equivalent to NETIF_F_HW_CSUM.

Signed-off-by: Michał Mirosław 
Signed-off-by: David S. Miller

net: Allow ethtool to set interface in loopback mode.

2011-05-08T22:59:12+00:00

This patch enables ethtool to set the loopback mode on a given interface.
By configuring the interface in loopback mode in conjunction with a policy
route / rule, a userland application can stress the egress / ingress path
exposing the flows of the change in progress and potentially help developer(s)
understand the impact of those changes without even sending a packet out
on the network.

Following set of commands illustrates one such example -
    a) ip -4 addr add 192.168.1.1/24 dev eth1
    b) ip -4 rule add from all iif eth1 lookup 250
    c) ip -4 route add local 0/0 dev lo proto kernel scope host table 250
    d) arp -Ds 192.168.1.100 eth1
    e) arp -Ds 192.168.1.200 eth1
    f) sysctl -w net.ipv4.ip_nonlocal_bind=1
    g) sysctl -w net.ipv4.conf.all.accept_local=1
    # Assuming that the machine has 8 cores
    h) taskset 000f netserver -L 192.168.1.200
    i) taskset 00f0 netperf -t TCP_CRR -L 192.168.1.100 -H 192.168.1.200 -l 30

Signed-off-by: Mahesh Bandewar 
Acked-by: Ben Hutchings 
Signed-off-by: David S. Miller