Merge 'net' into 'net-next' to get the AF_PACKET bug fix that
Daniel's direct transmit changes depend upon.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit e40526cb introduced a cached dev pointer, that gets
hooked into register_prot_hook(), __unregister_prot_hook() to
update the device used for the send path.

We need to fix this up, as otherwise this will not work with
sockets created with protocol = 0, plus with sll_protocol = 0
passed via sockaddr_ll when doing the bind.

So instead, assign the pointer directly. The compiler can inline
these helper functions automagically.

While at it, also assume the cached dev fast-path as likely(),
and document this variant of socket creation as it seems it is
not widely used (seems not even the author of TX_RING was aware
of that in his reference example [1]). Tested with reproducer
from e40526cb.

 [1] http://wiki.ipxwarzone.com/index.php5?title=Linux_packet_mmap#Example

Fixes: e40526cb ("packet: fix use after free race in send path when dev is released")
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Tested-by: NSalam Noureddine <noureddine@aristanetworks.com>
Tested-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 6da7c8fc ("qdisc: allow setting default queuing discipline")
added the ability to change default qdisc from pfifo_fast to say fq

But as most modern ethernet devices are multiqueue, we cant really
see all the statistics from "tc -s qdisc show", as the default root
qdisc is mq.

This patch adds the calls to qdisc_list_add() to mq and mqprio
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates

This series contains updates to i40e only.

Jacob provides a i40e patch to get 1588 work correctly by separating
TSYNVALID and TSYNINDX fields in the receive descriptor.

Jesse provides several i40e patches, first to correct the checking
of the multi-bit state.  The hash is reported correctly in the RSS
field if and only if the filter status is 3.  Other values of the
filter status mean different things and we should not depend on a
bitwise result.  Then provides a patch to enable a couple of
workarounds based on revision ID that allow the driver to work
more fully on early hardware.

Shannon provides several i40e patches as well.  First sets the media
type in the hardware structure based on the external connection type.
Then provides a patch to only setup the rings that will be used.  Lastly
provides a fix where the TESTING state was still set when exiting the
ethtool diagnostics.

Kevin Scott provides one i40e patch to add a new flag to the i40e_add_veb()
which allows the driver to request the hardware to filter on layer 2
parameters.

Anjali provides four i40e patches, first refactors the reset code in
order to re-size queues and vectors while the interface is still up.
Then provides a patch to enable all PCTYPEs expect FCoE for RSS.  Adds
a message to notify the user of how many VFs are initialized on each
port.  Lastly adds a new variable to track the number of PF instances,
this is a global counter on purpose so that each PF loaded has a
unique ID.

Catherine bumps the driver version.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Track the number of physical functions (PFs) found, this is a global counter
on purpose so that each pf loaded has a unique ID.

Change-Id: I74d618520afbce4a774d0235449e3b5f97ff6d4a
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Print a message to notify the user of how many VFs are initialized on each
port.

Change-Id: I29ac2acc478ee4e588fd6ffcc35133d4c6607ca9
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Put the print and reset statements in the actual test functions to make
them more self-contained, and only run the reset for tests that need it.

Change-Id: Ic70f49b11bf8bae82e59d8fd25b46215c90c4510
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Fix a bug where the TESTING state was still set when
exiting the ethtool diagnostics.

Change-Id: Ic47950d2e86a67167d1d282256d477cecd86d820
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The VSI may be allocated more queues (alloc_queue_pairs) than actually
are to be used (num_queue_pairs), so only allocate rings for the queues
to be used.  The numbers will likely be the same for most VSIs, but can
be different based on how TCs are assigned and enabled.

Change-Id: Ie40f7ad0affbc4b45d6f049bcf02ee2fa24edc74
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

RSS can steer packets based on recognition of all
sorts of different headers.  Enable some more of them.

Change-Id: I2264dedae66fb0bceca6fb6e772e050e3ca8efc8
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

In order to re-size queues and vectors while the interface is
still up, we need to be able to call functions to free and
re-allocate without bringing down the VSI.

We also need to reset the existing setup, update the
configuration and then rebuild again. This requires us to have
the reset flow broken down into two parts.

Change-Id: I374dd25aabf769decda69b676491c7b7730a4635
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Update the driver version to 0.3.12-k
Signed-off-by: NCatherine Sullivan <catherine.sullivan@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Whitespace fixes

Change-Id: I95f4d02e4a2a92d6b6fca3ae2b7865c4b916a9bb
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>

Enable a couple of workarounds based on revision ID that allow the
driver to work more fully on early hardware.
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Add a new flag to the add VEB command which allows the
driver to request the hardware to filter on L2 parameters.

This is an implementation of the driver access to a new firmware
feature.

Change-Id: Id61d3cad4125bdc68b8fd9d555c448a10c344b6b
Signed-off-by: NKevin Scott <kevin.c.scott@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Set the media type in the hardware structure, based
on the external connection type.

Add Direct Attach to the type of media reported by ethtool.

Change-Id: I4ad2f5bf882766d6e737fac4477abf049491b3b3
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The hash is reported correctly in the rss field if and only if
the filter status is 3.  Other values of filter status mean
different things and we shouldn't depend on a bitwise result.

The issue was that
a & b --> returns true for b={1,2,3}
the fix is
a & b == b

Also refactor this function to use constant operations because we
are in fast path.

Change-Id: I4e29be87439c1cf8b60bc31bea29dff89596c013
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

In order to get 1588 to work correctly the defines need a bit
of a tweak.

Change-Id: Ie50ce2a18e1593441f1560411e5a4f51c6d48aaa
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Add a new check for CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to reduce
the number of or's used in the ether_addr_equal comparison to very
slightly improve function performance.

Simplify the ether_addr_equal_64bits implementation.
Integrate and remove the zap_last_2bytes helper as it's now
used only once.

Remove the now unused compare_ether_addr function.

Update the unaligned-memory-access documentation to remove the
compare_ether_addr description and show how unaligned accesses
could occur with ether_addr_equal.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

use pr_<level> instead of printk(LEVEL)
Signed-off-by: NWang Weidong <wangweidong1@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Creating an address with this flag set will result in kernel taking care
of temporary addresses in the same way as if the address was created by
kernel itself (after RA receive). This allows userspace applications
implementing the autoconfiguration (NetworkManager for example) to
implement ipv6 addresses privacy.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NThomas Haller <thaller@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no more space in u8 ifa_flags. So do what davem suffested and
add another netlink attr called IFA_FLAGS for carry more flags.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NThomas Haller <thaller@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a packet with invalid length arrives, ensure that the packet
is freed correctly if mergeable packet buffers and big packets
(GUEST_TSO4) are both enabled.
Signed-off-by: NMichael Dalton <mwdalton@google.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Acked-by: NAndrew Vagin <avagin@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current code unmaps the DMA mapping created for rx skb_buff's by
using the data_size as the the mapping size. This is wrong since the
correct size to specify should match the size used to create the mapping.

This commit removes the following DMA_API_DEBUG warning:

------------[ cut here ]------------
WARNING: at lib/dma-debug.c:887 check_unmap+0x3a8/0x860()
mvneta d0070000.ethernet: DMA-API: device driver frees DMA memory with different size [device address=0x000000002eb80000] [map size=1600 bytes] [unmap size=66 bytes]
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.21-01444-ga88ae13-dirty #92
[<c0013600>] (unwind_backtrace+0x0/0xf8) from [<c0010fb8>] (show_stack+0x10/0x14)
[<c0010fb8>] (show_stack+0x10/0x14) from [<c001afa0>] (warn_slowpath_common+0x48/0x68)
[<c001afa0>] (warn_slowpath_common+0x48/0x68) from [<c001b01c>] (warn_slowpath_fmt+0x30/0x40)
[<c001b01c>] (warn_slowpath_fmt+0x30/0x40) from [<c018d0fc>] (check_unmap+0x3a8/0x860)
[<c018d0fc>] (check_unmap+0x3a8/0x860) from [<c018d734>] (debug_dma_unmap_page+0x64/0x70)
[<c018d734>] (debug_dma_unmap_page+0x64/0x70) from [<c0233f78>] (mvneta_rx+0xec/0x468)
[<c0233f78>] (mvneta_rx+0xec/0x468) from [<c023436c>] (mvneta_poll+0x78/0x16c)
[<c023436c>] (mvneta_poll+0x78/0x16c) from [<c02db468>] (net_rx_action+0x94/0x160)
[<c02db468>] (net_rx_action+0x94/0x160) from [<c0021e68>] (__do_softirq+0xe8/0x1d0)
[<c0021e68>] (__do_softirq+0xe8/0x1d0) from [<c0021ff8>] (do_softirq+0x4c/0x58)
[<c0021ff8>] (do_softirq+0x4c/0x58) from [<c0022228>] (irq_exit+0x58/0x90)
[<c0022228>] (irq_exit+0x58/0x90) from [<c000e7c8>] (handle_IRQ+0x3c/0x94)
[<c000e7c8>] (handle_IRQ+0x3c/0x94) from [<c0008548>] (armada_370_xp_handle_irq+0x4c/0xb4)
[<c0008548>] (armada_370_xp_handle_irq+0x4c/0xb4) from [<c000dc20>] (__irq_svc+0x40/0x50)
Exception stack(0xc04f1f70 to 0xc04f1fb8)
1f60:                                     c1fe46f8 00000000 00001d92 00001d92
1f80: c04f0000 c04f0000 c04f84a4 c03e081c c05220e7 00000001 c05220e7 c04f0000
1fa0: 00000000 c04f1fb8 c000eaf8 c004c048 60000113 ffffffff
[<c000dc20>] (__irq_svc+0x40/0x50) from [<c004c048>] (cpu_startup_entry+0x54/0x128)
[<c004c048>] (cpu_startup_entry+0x54/0x128) from [<c04c1a14>] (start_kernel+0x29c/0x2f0)
[<c04c1a14>] (start_kernel+0x29c/0x2f0) from [<00008074>] (0x8074)
---[ end trace d4955f6acd178110 ]---
Mapped at:
 [<c018d600>] debug_dma_map_page+0x4c/0x11c
 [<c0235d6c>] mvneta_setup_rxqs+0x398/0x598
 [<c0236084>] mvneta_open+0x40/0x17c
 [<c02dbbd4>] __dev_open+0x9c/0x100
 [<c02dbe58>] __dev_change_flags+0x7c/0x134
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

br_stp_rcv() is reached by non-rx_handler path. That means there is no
guarantee that dev is bridge port and therefore simple NULL check of
->rx_handler_data is not enough. There is need to check if dev is really
bridge port and since only rcu read lock is held here, do it by checking
->rx_handler pointer.

Note that synchronize_net() in netdev_rx_handler_unregister() ensures
this approach as valid.

Introduced originally by:
commit f350a0a8
  "bridge: use rx_handler_data pointer to store net_bridge_port pointer"

Fixed but not in the best way by:
commit b5ed54e9
  "bridge: fix RCU races with bridge port"

Reintroduced by:
commit 716ec052
  "bridge: fix NULL pointer deref of br_port_get_rcu"

Please apply to stable trees as well. Thanks.

RH bugzilla reference: https://bugzilla.redhat.com/show_bug.cgi?id=1025770Reported-by: NLaine Stump <laine@redhat.com>
Debugged-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

free_netdev calls netif_napi_del too, but it's too late, because napi
structures are placed on vi->rq. netif_napi_add() is called from
virtnet_alloc_queues.

general protection fault: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in: ip6table_filter ip6_tables iptable_filter ip_tables virtio_balloon pcspkr virtio_net(-) i2c_pii
CPU: 1 PID: 347 Comm: rmmod Not tainted 3.13.0-rc2+ #171
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff8800b779c420 ti: ffff8800379e0000 task.ti: ffff8800379e0000
RIP: 0010:[<ffffffff81322e19>]  [<ffffffff81322e19>] __list_del_entry+0x29/0xd0
RSP: 0018:ffff8800379e1dd0  EFLAGS: 00010a83
RAX: 6b6b6b6b6b6b6b6b RBX: ffff8800379c2fd0 RCX: dead000000200200
RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000001 RDI: ffff8800379c2fd0
RBP: ffff8800379e1dd0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8800379c2f90
R13: ffff880037839160 R14: 0000000000000000 R15: 00000000013352f0
FS:  00007f1400e34740(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f464124c763 CR3: 00000000b68cf000 CR4: 00000000000006e0
Stack:
 ffff8800379e1df0 ffffffff8155beab 6b6b6b6b6b6b6b2b ffff8800378391c0
 ffff8800379e1e18 ffffffff8156499b ffff880037839be0 ffff880037839d20
 ffff88003779d3f0 ffff8800379e1e38 ffffffffa003477c ffff88003779d388
Call Trace:
 [<ffffffff8155beab>] netif_napi_del+0x1b/0x80
 [<ffffffff8156499b>] free_netdev+0x8b/0x110
 [<ffffffffa003477c>] virtnet_remove+0x7c/0x90 [virtio_net]
 [<ffffffff813ae323>] virtio_dev_remove+0x23/0x80
 [<ffffffff813f62ef>] __device_release_driver+0x7f/0xf0
 [<ffffffff813f6ca0>] driver_detach+0xc0/0xd0
 [<ffffffff813f5f28>] bus_remove_driver+0x58/0xd0
 [<ffffffff813f72ec>] driver_unregister+0x2c/0x50
 [<ffffffff813ae65e>] unregister_virtio_driver+0xe/0x10
 [<ffffffffa0036942>] virtio_net_driver_exit+0x10/0x6ce [virtio_net]
 [<ffffffff810d7cf2>] SyS_delete_module+0x172/0x220
 [<ffffffff810a732d>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff810f5d4c>] ? __audit_syscall_entry+0x9c/0xf0
 [<ffffffff81677f69>] system_call_fastpath+0x16/0x1b
Code: 00 00 55 48 8b 17 48 b9 00 01 10 00 00 00 ad de 48 8b 47 08 48 89 e5 48 39 ca 74 29 48 b9 00 02 20 00 00 00
RIP  [<ffffffff81322e19>] __list_del_entry+0x29/0xd0
 RSP <ffff8800379e1dd0>
---[ end trace d5931cd3f87c9763 ]---

Fixes: 986a4f4d (virtio_net: multiqueue support)
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

free_unused_bufs must check vi->mergeable_rx_bufs before
vi->big_packets, because we use this sequence in other places.
Otherwise we allocate buffer of one type, then free it as another
type.

general protection fault: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in: ip6table_filter ip6_tables iptable_filter ip_tables pcspkr virtio_balloon virtio_net(-) i2c_pii
CPU: 0 PID: 400 Comm: rmmod Not tainted 3.13.0-rc2+ #170
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff8800b6d2a210 ti: ffff8800aed32000 task.ti: ffff8800aed32000
RIP: 0010:[<ffffffffa00345f3>]  [<ffffffffa00345f3>] free_unused_bufs+0xc3/0x190 [virtio_net]
RSP: 0018:ffff8800aed33dd8  EFLAGS: 00010202
RAX: ffff8800b1fe2c00 RBX: ffff8800b66a7240 RCX: 6b6b6b6b6b6b6b6b
RDX: 6b6b6b6b6b6b6b6b RSI: ffff8800b8419a68 RDI: ffff8800b66a1148
RBP: ffff8800aed33e00 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8800b66a1148 R14: 0000000000000000 R15: 000077ff80000000
FS:  00007fc4f9c4e740(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f63f432f000 CR3: 00000000b6538000 CR4: 00000000000006f0
Stack:
 ffff8800b66a7240 ffff8800b66a7380 ffff8800377bd3f0 0000000000000000
 00000000023302f0 ffff8800aed33e18 ffffffffa00346e2 ffff8800b66a7240
 ffff8800aed33e38 ffffffffa003474d ffff8800377bd388 ffff8800377bd390
Call Trace:
 [<ffffffffa00346e2>] remove_vq_common+0x22/0x40 [virtio_net]
 [<ffffffffa003474d>] virtnet_remove+0x4d/0x90 [virtio_net]
 [<ffffffff813ae303>] virtio_dev_remove+0x23/0x80
 [<ffffffff813f62cf>] __device_release_driver+0x7f/0xf0
 [<ffffffff813f6c80>] driver_detach+0xc0/0xd0
 [<ffffffff813f5f08>] bus_remove_driver+0x58/0xd0
 [<ffffffff813f72cc>] driver_unregister+0x2c/0x50
 [<ffffffff813ae63e>] unregister_virtio_driver+0xe/0x10
 [<ffffffffa0036852>] virtio_net_driver_exit+0x10/0x7be [virtio_net]
 [<ffffffff810d7cf2>] SyS_delete_module+0x172/0x220
 [<ffffffff810a732d>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff810f5d4c>] ? __audit_syscall_entry+0x9c/0xf0
 [<ffffffff81677f69>] system_call_fastpath+0x16/0x1b
Code: c0 74 55 0f 1f 44 00 00 80 7b 30 00 74 7a 48 8b 50 30 4c 89 e6 48 03 73 20 48 85 d2 0f 84 bb 00 00 00 66 0f
RIP  [<ffffffffa00345f3>] free_unused_bufs+0xc3/0x190 [virtio_net]
 RSP <ffff8800aed33dd8>
---[ end trace edb570ea923cce9c ]---

Fixes: 2613af0e (virtio_net: migrate mergeable rx buffers to page frag allocators)
Cc: Michael Dalton <mwdalton@google.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some network drivers use dev_kfree_skb_any() and dev_kfree_skb_irq()
helpers to free skbs, both for dropped packets and TX completed ones.

We need to separate the two causes to get better diagnostics
given by dropwatch or "perf record -e skb:kfree_skb"

This patch provides two new helpers, dev_consume_skb_any() and
dev_consume_skb_irq() to be used for consumed skbs.

__dev_kfree_skb_irq() is slightly optimized to remove one
atomic_dec_and_test() in fast path, and use this_cpu_{r|w} accessors.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>