linux-stable.git/net/core/dev.c, branch v3.14.8

net-gro: reset skb->truesize in napi_reuse_skb()

2014-05-31T20:20:39+00:00

[ Upstream commit e33d0ba8047b049c9262fdb1fcafb93cb52ceceb ]

Recycling skb always had been very tough...

This time it appears GRO layer can accumulate skb->truesize
adjustments made by drivers when they attach a fragment to skb.

skb_gro_receive() can only subtract from skb->truesize the used part
of a fragment.

I spotted this problem seeing TcpExtPruneCalled and
TcpExtTCPRcvCollapsed that were unexpected with a recent kernel, where
TCP receive window should be sized properly to accept traffic coming
from a driver not overshooting skb->truesize.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: gro: make sure skb->cb[] initial content has not to be zero

2014-05-31T20:20:38+00:00

[ Upstream commit 29e98242783ed3ba569797846a606ba66f781625 ]

Starting from linux-3.13, GRO attempts to build full size skbs.

Problem is the commit assumed one particular field in skb->cb[]
was clean, but it is not the case on some stacked devices.

Timo reported a crash in case traffic is decrypted before
reaching a GRE device.

Fix this by initializing NAPI_GRO_CB(skb)->last at the right place,
this also removes one conditional.

Thanks a lot to Timo for providing full reports and bisecting this.

Fixes: 8a29111c7ca6 ("net: gro: allow to build full sized skb")
Bisected-by: Timo Teras 
Signed-off-by: Eric Dumazet 
Tested-by: Timo Teräs 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

rtnetlink: wait for unregistering devices in rtnl_link_unregister()

2014-05-31T20:20:38+00:00

[ Upstream commit 200b916f3575bdf11609cb447661b8d5957b0bbf ]

From: Cong Wang 

commit 50624c934db18ab90 (net: Delay default_device_exit_batch until no
devices are unregistering) introduced rtnl_lock_unregistering() for
default_device_exit_batch(). Same race could happen we when rmmod a driver
which calls rtnl_link_unregister() as we call dev->destructor without rtnl
lock.

For long term, I think we should clean up the mess of netdev_run_todo()
and net namespce exit code.

Cc: Eric W. Biederman 
Cc: David S. Miller 
Signed-off-by: Cong Wang 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

vlan: Fix lockdep warning with stacked vlan devices.

2014-05-31T20:20:34+00:00

[ Upstream commit d38569ab2bba6e6b3233acfc3a84cdbcfbd1f79f ]

This reverts commit dc8eaaa006350d24030502a4521542e74b5cb39f.
	vlan: Fix lockdep warning when vlan dev handle notification

Instead we use the new new API to find the lock subclass of
our vlan device.  This way we can support configurations where
vlans are interspersed with other devices:
  bond -> vlan -> macvlan -> vlan

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Find the nesting level of a given device by type.

2014-05-31T20:20:34+00:00

[ Upstream commit 4085ebe8c31face855fd01ee40372cb4aab1df3a ]

Multiple devices in the kernel can be stacked/nested and they
need to know their nesting level for the purposes of lockdep.
This patch provides a generic function that determines a nesting
level of a particular device by its type (ex: vlan, macvlan, etc).
We only care about nesting of the same type of devices.

For example:
  eth0 <- vlan0.10 <- macvlan0 <- vlan1.20

The nesting level of vlan1.20 would be 1, since there is another vlan
in the stack under it.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

vlan: Fix lockdep warning when vlan dev handle notification

2014-05-31T20:20:34+00:00

[ Upstream commit dc8eaaa006350d24030502a4521542e74b5cb39f ]

When I open the LOCKDEP config and run these steps:

modprobe 8021q
vconfig add eth2 20
vconfig add eth2.20 30
ifconfig eth2 xx.xx.xx.xx

then the Call Trace happened:

[32524.386288] =============================================
[32524.386293] [ INFO: possible recursive locking detected ]
[32524.386298] 3.14.0-rc2-0.7-default+ #35 Tainted: G           O
[32524.386302] ---------------------------------------------
[32524.386306] ifconfig/3103 is trying to acquire lock:
[32524.386310]  (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_mc_sync+0x64/0xb0
[32524.386326]
[32524.386326] but task is already holding lock:
[32524.386330]  (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_set_rx_mode+0x23/0x40
[32524.386341]
[32524.386341] other info that might help us debug this:
[32524.386345]  Possible unsafe locking scenario:
[32524.386345]
[32524.386350]        CPU0
[32524.386352]        ----
[32524.386354]   lock(&vlan_netdev_addr_lock_key/1);
[32524.386359]   lock(&vlan_netdev_addr_lock_key/1);
[32524.386364]
[32524.386364]  *** DEADLOCK ***
[32524.386364]
[32524.386368]  May be due to missing lock nesting notation
[32524.386368]
[32524.386373] 2 locks held by ifconfig/3103:
[32524.386376]  #0:  (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20
[32524.386387]  #1:  (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_set_rx_mode+0x23/0x40
[32524.386398]
[32524.386398] stack backtrace:
[32524.386403] CPU: 1 PID: 3103 Comm: ifconfig Tainted: G           O 3.14.0-rc2-0.7-default+ #35
[32524.386409] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[32524.386414]  ffffffff81ffae40 ffff8800d9625ae8 ffffffff814f68a2 ffff8800d9625bc8
[32524.386421]  ffffffff810a35fb ffff8800d8a8d9d0 00000000d9625b28 ffff8800d8a8e5d0
[32524.386428]  000003cc00000000 0000000000000002 ffff8800d8a8e5f8 0000000000000000
[32524.386435] Call Trace:
[32524.386441]  [] dump_stack+0x6a/0x78
[32524.386448]  [] __lock_acquire+0x7ab/0x1940
[32524.386454]  [] ? __lock_acquire+0x3ea/0x1940
[32524.386459]  [] lock_acquire+0xe4/0x110
[32524.386464]  [] ? dev_mc_sync+0x64/0xb0
[32524.386471]  [] _raw_spin_lock_nested+0x2a/0x40
[32524.386476]  [] ? dev_mc_sync+0x64/0xb0
[32524.386481]  [] dev_mc_sync+0x64/0xb0
[32524.386489]  [] vlan_dev_set_rx_mode+0x2b/0x50 [8021q]
[32524.386495]  [] __dev_set_rx_mode+0x5f/0xb0
[32524.386500]  [] dev_set_rx_mode+0x2b/0x40
[32524.386506]  [] __dev_open+0xef/0x150
[32524.386511]  [] __dev_change_flags+0xa7/0x190
[32524.386516]  [] dev_change_flags+0x32/0x80
[32524.386524]  [] devinet_ioctl+0x7d6/0x830
[32524.386532]  [] ? dev_ioctl+0x34b/0x660
[32524.386540]  [] inet_ioctl+0x80/0xa0
[32524.386550]  [] sock_do_ioctl+0x2d/0x60
[32524.386558]  [] sock_ioctl+0x82/0x2a0
[32524.386568]  [] do_vfs_ioctl+0x93/0x590
[32524.386578]  [] ? rcu_read_lock_held+0x45/0x50
[32524.386586]  [] ? __fget_light+0x105/0x110
[32524.386594]  [] SyS_ioctl+0x91/0xb0
[32524.386604]  [] system_call_fastpath+0x16/0x1b

========================================================================

The reason is that all of the addr_lock_key for vlan dev have the same class,
so if we change the status for vlan dev, the vlan dev and its real dev will
hold the same class of addr_lock_key together, so the warning happened.

we should distinguish the lock depth for vlan dev and its real dev.

v1->v2: Convert the vlan_netdev_addr_lock_key to an array of eight elements, which
	could support to add 8 vlan id on a same vlan dev, I think it is enough for current
	scene, because a netdev's name is limited to IFNAMSIZ which could not hold 8 vlan id,
	and the vlan dev would not meet the same class key with its real dev.

	The new function vlan_dev_get_lockdep_subkey() will return the subkey and make the vlan
	dev could get a suitable class key.

v2->v3: According David's suggestion, I use the subclass to distinguish the lock key for vlan dev
	and its real dev, but it make no sense, because the difference for subclass in the
	lock_class_key doesn't mean that the difference class for lock_key, so I use lock_depth
	to distinguish the different depth for every vlan dev, the same depth of the vlan dev
	could have the same lock_class_key, I import the MAX_LOCK_DEPTH from the include/linux/sched.h,
	I think it is enough here, the lockdep should never exceed that value.

v3->v4: Add a huge array of locking keys will waste static kernel memory and is not a appropriate method,
	we could use _nested() variants to fix the problem, calculate the depth for every vlan dev,
	and use the depth as the subclass for addr_lock_key.

Signed-off-by: Ding Tianhong 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Start with correct mac_len in skb_network_protocol

2014-05-31T20:20:34+00:00

[ Upstream commit 1e785f48d29a09b6cf96db7b49b6320dada332e1 ]

Sometimes, when the packet arrives at skb_mac_gso_segment()
its skb->mac_len already accounts for some of the mac lenght
headers in the packet.  This seems to happen when forwarding
through and OpenSSL tunnel.

When we start looking for any vlan headers in skb_network_protocol()
we seem to ignore any of the already known mac headers and start
with an ETH_HLEN.  This results in an incorrect offset, dropped
TSO frames and general slowness of the connection.

We can start counting from the known skb->mac_len
and return at least that much if all mac level headers
are known and accounted for.

Fixes: 53d6471cef17262d3ad1c7ce8982a234244f68ec (net: Account for all vlan headers in skb_mac_gso_segment)
CC: Eric Dumazet 
CC: Daniel Borkman 
Tested-by: Martin Filip 
Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Account for all vlan headers in skb_mac_gso_segment

2014-03-28T21:10:36+00:00

skb_network_protocol() already accounts for multiple vlan
headers that may be present in the skb.  However, skb_mac_gso_segment()
doesn't know anything about it and assumes that skb->mac_len
is set correctly to skip all mac headers.  That may not
always be the case.  If we are simply forwarding the packet (via
bridge or macvtap), all vlan headers may not be accounted for.

A simple solution is to allow skb_network_protocol to return
the vlan depth it has calculated.  This way skb_mac_gso_segment
will correctly skip all mac headers.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

net: core: introduce netif_skb_dev_features

2014-02-13T22:17:02+00:00

Will be used by upcoming ipv4 forward path change that needs to
determine feature mask using skb->dst->dev instead of skb->dev.

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

net: Mark functions as static in core/dev.c

2014-02-10T01:32:49+00:00

Mark functions as static in core/dev.c because they are not used outside
this file.

This eliminates the following warning in core/dev.c:
net/core/dev.c:2806:5: warning: no previous prototype for ‘__dev_queue_xmit’ [-Wmissing-prototypes]
net/core/dev.c:4640:5: warning: no previous prototype for ‘netdev_adjacent_sysfs_add’ [-Wmissing-prototypes]
net/core/dev.c:4650:6: warning: no previous prototype for ‘netdev_adjacent_sysfs_del’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria 
Reviewed-by: Josh Triplett 
Reviewed-by: Veaceslav Falico 
Signed-off-by: David S. Miller