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  1. 26 4月, 2011 2 次提交
  3. 23 4月, 2011 1 次提交
  5. 13 4月, 2011 4 次提交
  7. 05 4月, 2011 1 次提交
    • T
      net: Allow no-cache copy from user on transmit · c6e1a0d1
      由 Tom Herbert 提交于 
      This patch uses __copy_from_user_nocache on transmit to bypass data
cache for a performance improvement.  skb_add_data_nocache and
skb_copy_to_page_nocache can be called by sendmsg functions to use
this feature, initial support is in tcp_sendmsg.  This functionality is
configurable per device using ethtool.

Presumably, this feature would only be useful when the driver does
not touch the data.  The feature is turned on by default if a device
indicates that it does some form of checksum offload; it is off by
default for devices that do no checksum offload or indicate no checksum
is necessary.  For the former case copy-checksum is probably done
anyway, in the latter case the device is likely loopback in which case
the no cache copy is probably not beneficial.

This patch was tested using 200 instances of netperf TCP_RR with
1400 byte request and one byte reply.  Platform is 16 core AMD x86.

No-cache copy disabled:
   672703 tps, 97.13% utilization
   50/90/99% latency:244.31 484.205 1028.41

No-cache copy enabled:
   702113 tps, 96.16% utilization,
   50/90/99% latency 238.56 467.56 956.955

Using 14000 byte request and response sizes demonstrate the
effects more dramatically:

No-cache copy disabled:
   79571 tps, 34.34 %utlization
   50/90/95% latency 1584.46 2319.59 5001.76

No-cache copy enabled:
   83856 tps, 34.81% utilization
   50/90/95% latency 2508.42 2622.62 2735.88

Note especially the effect on latency tail (95th percentile).

This seems to provide a nice performance improvement and is
consistent in the tests I ran.  Presumably, this would provide
the greatest benfits in the presence of an application workload
stressing the cache and a lot of transmit data happening.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c6e1a0d1
  9. 03 4月, 2011 1 次提交
  11. 31 3月, 2011 1 次提交
  13. 30 3月, 2011 1 次提交
  15. 28 3月, 2011 2 次提交
  17. 22 3月, 2011 1 次提交
  19. 17 3月, 2011 1 次提交
  21. 10 3月, 2011 1 次提交
    • V
      net: don't allow CAP_NET_ADMIN to load non-netdev kernel modules · 8909c9ad
      由 Vasiliy Kulikov 提交于 
      Since a8f80e8f any process with
CAP_NET_ADMIN may load any module from /lib/modules/.  This doesn't mean
that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are
limited to /lib/modules/**.  However, CAP_NET_ADMIN capability shouldn't
allow anybody load any module not related to networking.

This patch restricts an ability of autoloading modules to netdev modules
with explicit aliases.  This fixes CVE-2011-1019.

Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior
of loading netdev modules by name (without any prefix) for processes
with CAP_SYS_MODULE to maintain the compatibility with network scripts
that use autoloading netdev modules by aliases like "eth0", "wlan0".

Currently there are only three users of the feature in the upstream
kernel: ipip, ip_gre and sit.

    root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) --
    root@albatros:~# grep Cap /proc/$$/status
    CapInh:	0000000000000000
    CapPrm:	fffffff800001000
    CapEff:	fffffff800001000
    CapBnd:	fffffff800001000
    root@albatros:~# modprobe xfs
    FATAL: Error inserting xfs
    (/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted
    root@albatros:~# lsmod | grep xfs
    root@albatros:~# ifconfig xfs
    xfs: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep xfs
    root@albatros:~# lsmod | grep sit
    root@albatros:~# ifconfig sit
    sit: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep sit
    root@albatros:~# ifconfig sit0
    sit0      Link encap:IPv6-in-IPv4
	      NOARP  MTU:1480  Metric:1

    root@albatros:~# lsmod | grep sit
    sit                    10457  0
    tunnel4                 2957  1 sit

For CAP_SYS_MODULE module loading is still relaxed:

    root@albatros:~# grep Cap /proc/$$/status
    CapInh:	0000000000000000
    CapPrm:	ffffffffffffffff
    CapEff:	ffffffffffffffff
    CapBnd:	ffffffffffffffff
    root@albatros:~# ifconfig xfs
    xfs: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep xfs
    xfs                   745319  0

Reference: https://lkml.org/lkml/2011/2/24/203Signed-off-by: NVasiliy Kulikov <segoon@openwall.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NKees Cook <kees.cook@canonical.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      8909c9ad
  23. 08 3月, 2011 1 次提交
  25. 01 3月, 2011 1 次提交
  27. 24 2月, 2011 2 次提交
  29. 19 2月, 2011 2 次提交
  31. 18 2月, 2011 2 次提交
  33. 16 2月, 2011 2 次提交
  35. 14 2月, 2011 2 次提交
  37. 09 2月, 2011 1 次提交
    • D
      net: Fix lockdep regression caused by initializing netdev queues too early. · 8d3bdbd5
      由 David S. Miller 提交于 
      In commit aa942104 ("net: init ingress
queue") we moved the allocation and lock initialization of the queues
into alloc_netdev_mq() since register_netdevice() is way too late.

The problem is that dev->type is not setup until the setup()
callback is invoked by alloc_netdev_mq(), and the dev->type is
what determines the lockdep class to use for the locks in the
queues.

Fix this by doing the queue allocation after the setup() callback
runs.

This is safe because the setup() callback is not allowed to make any
state changes that need to be undone on error (memory allocations,
etc.).  It may, however, make state changes that are undone by
free_netdev() (such as netif_napi_add(), which is done by the
ipoib driver's setup routine).

The previous code also leaked a reference to the &init_net namespace
object on RX/TX queue allocation failures.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8d3bdbd5
  39. 03 2月, 2011 1 次提交
  41. 01 2月, 2011 1 次提交
  43. 30 1月, 2011 1 次提交
    • H
      gro: Reset dev pointer on reuse · 66c46d74
      由 Herbert Xu 提交于 
      On older kernels the VLAN code may zero skb->dev before dropping
it and causing it to be reused by GRO.

Unfortunately we didn't reset skb->dev in that case which causes
the next GRO user to get a bogus skb->dev pointer.

This particular problem no longer happens with the current upstream
kernel due to changes in VLAN processing.

However, for correctness we should still reset the skb->dev pointer
in the GRO reuse function in case a future user does the same thing.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      66c46d74
  45. 28 1月, 2011 1 次提交
    • E
      net: fix dev_seq_next() · ccf43438
      由 Eric Dumazet 提交于 
      Commit c6d14c84 (net: Introduce for_each_netdev_rcu() iterator)
added a race in dev_seq_next().

The rcu_dereference() call should be done _before_ testing the end of
list, or we might return a wrong net_device if a concurrent thread
changes net_device list under us.

Note : discovered thanks to a sparse warning :

net/core/dev.c:3919:9: error: incompatible types in comparison expression
(different address spaces)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ccf43438
  47. 25 1月, 2011 5 次提交
  49. 22 1月, 2011 1 次提交
  51. 21 1月, 2011 1 次提交
    • E
      net_sched: RCU conversion of stab · a2da570d
      由 Eric Dumazet 提交于 
      This patch converts stab qdisc management to RCU, so that we can perform
the qdisc_calculate_pkt_len() call before getting qdisc lock.

This shortens the lock's held time in __dev_xmit_skb().

This permits more qdiscs to get TCQ_F_CAN_BYPASS status, avoiding lot of
cache misses and so reducing latencies.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Jesper Dangaard Brouer <hawk@diku.dk>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: Jamal Hadi Salim <hadi@cyberus.ca>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a2da570d