vlan: adopt u64_stats_t

As explained in commit 316580b69d0a ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.

Add READ_ONCE() when reading rx_errors & tx_dropped.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: macvlan: add net device refcount tracker

Add net device refcount tracker to macvlan.

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: macvlan_count_rx() needs to be aware of preemption

macvlan_count_rx() can be called from process context, it is thus
necessary to disable preemption before calling u64_stats_update_begin()

syzbot was able to spot this on 32bit arch:

WARNING: CPU: 1 PID: 4632 at include/linux/seqlock.h:271 __seqprop_assert include/linux/seqlock.h:271 [inline]
WARNING: CPU: 1 PID: 4632 at include/linux/seqlock.h:271 __seqprop_assert.constprop.0+0xf0/0x11c include/linux/seqlock.h:269
Modules linked in:
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 4632 Comm: kworker/1:3 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: ARM-Versatile Express
Workqueue: events macvlan_process_broadcast
Backtrace:
[<82740468>] (dump_backtrace) from [<827406dc>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252)
r7:00000080 r6:60000093 r5:00000000 r4:8422a3c4
[<827406c4>] (show_stack) from [<82751b58>] (__dump_stack lib/dump_stack.c:79 [inline])
[<827406c4>] (show_stack) from [<82751b58>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120)
[<82751aa0>] (dump_stack) from [<82741270>] (panic+0x130/0x378 kernel/panic.c:231)
r7:830209b4 r6:84069ea4 r5:00000000 r4:844350d0
[<82741140>] (panic) from [<80244924>] (__warn+0xb0/0x164 kernel/panic.c:605)
r3:8404ec8c r2:00000000 r1:00000000 r0:830209b4
r7:0000010f
[<80244874>] (__warn) from [<82741520>] (warn_slowpath_fmt+0x68/0xd4 kernel/panic.c:628)
r7:81363f70 r6:0000010f r5:83018e50 r4:00000000
[<827414bc>] (warn_slowpath_fmt) from [<81363f70>] (__seqprop_assert include/linux/seqlock.h:271 [inline])
[<827414bc>] (warn_slowpath_fmt) from [<81363f70>] (__seqprop_assert.constprop.0+0xf0/0x11c include/linux/seqlock.h:269)
r8:5a109000 r7:0000000f r6:a568dac0 r5:89802300 r4:00000001
[<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (u64_stats_update_begin include/linux/u64_stats_sync.h:128 [inline])
[<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (macvlan_count_rx include/linux/if_macvlan.h:47 [inline])
[<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (macvlan_broadcast+0x154/0x26c drivers/net/macvlan.c:291)
r5:89802300 r4:8a927740
[<8136499c>] (macvlan_broadcast) from [<81365020>] (macvlan_process_broadcast+0x258/0x2d0 drivers/net/macvlan.c:317)
r10:81364f78 r9:8a86d000 r8:8a9c7e7c r7:8413aa5c r6:00000000 r5:00000000
r4:89802840
[<81364dc8>] (macvlan_process_broadcast) from [<802696a4>] (process_one_work+0x2d4/0x998 kernel/workqueue.c:2275)
r10:00000008 r9:8404ec98 r8:84367a02 r7:ddfe6400 r6:ddfe2d40 r5:898dac80
r4:8a86d43c
[<802693d0>] (process_one_work) from [<80269dcc>] (worker_thread+0x64/0x54c kernel/workqueue.c:2421)
r10:00000008 r9:8a9c6000 r8:84006d00 r7:ddfe2d78 r6:898dac94 r5:ddfe2d40
r4:898dac80
[<80269d68>] (worker_thread) from [<80271f40>] (kthread+0x184/0x1a4 kernel/kthread.c:292)
r10:85247e64 r9:898dac80 r8:80269d68 r7:00000000 r6:8a9c6000 r5:89a2ee40
r4:8a97bd00
[<80271dbc>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x8a9c7fb0 to 0x8a9c7ff8)

Fixes: 412ca1550cbe ("macvlan: Move broadcasts into a work queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: Support for high multicast packet rate

Background:
Broadcast and multicast packages are enqueued for later processing.
This queue was previously hardcoded to 1000.

This proved insufficient for handling very high packet rates.
This resulted in packet drops for multicast.
While at the same time unicast worked fine.

The change:
This patch make the queue length adjustable to accommodate
for environments with very high multicast packet rate.
But still keeps the default value of 1000 unless specified.

The queue length is specified as a request per macvlan
using the IFLA_MACVLAN_BC_QUEUE_LEN parameter.

The actual used queue length will then be the maximum of
any macvlan connected to the same port. The actual used
queue length for the port can be retrieved (read only)
by the IFLA_MACVLAN_BC_QUEUE_LEN_USED parameter for verification.

This will be followed up by a patch to iproute2
in order to adjust the parameter from userspace.

Signed-off-by: Thomas Karlsson <thomas.karlsson@paneda.se>
Link: https://lore.kernel.org/r/dd4673b2-7eab-edda-6815-85c67ce87f63@paneda.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: remove unnecessary variables and callback

This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, ->ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes ->ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: Provide function for interfaces to release HW offload

This patch provides a basic function to allow a lower device to disable
macvlan offload if it was previously enabled on a given macvlan. The idea
here is to allow for recovery from failure should the lowerdev run out of
resources.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

macvlan: Add function to test for destination filtering support

This patch adds a function indicating if a given macvlan can fully supports
destination filtering, especially as it relates to unicast traffic. For
those macvlan interfaces that do not support destination filtering such
passthru or source mode filtering we should not be enabling offload
support.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

macvlan: macvlan_count_rx shouldn't be static inline AND extern

It doesn't make sense to define macvlan_count_rx as a static inline and
then add a forward declaration after that as an extern. I am dropping the
extern declaration since it seems like it is something that likely got
missed when the function was made an inline.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

macvlan: Rename fwd_priv to accel_priv and add accessor function

This change renames the fwd_priv member to accel_priv as this more
accurately reflects the actual purpose of this value. In addition I am
adding an accessor which will allow us to further abstract this in the
future if needed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

macvlan: fix memory hole in macvlan_dev

Move 'macaddr_count' from after 'netpoll' to after 'nest_level' to pack
and reduce a memory hole.

Fixes: 88ca59d1aaf28c25 (macvlan: remove unused fields in struct macvlan_dev)
Signed-off-by: Girish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

macvlan: remove unused fields in struct macvlan_dev

commit 635b8c8ecdd2 ("tap: Renaming tap related APIs, data structures,
macros") captured all the tap related fields into a new struct tap_dev.
However, it failed to remove those fields from struct macvlan_dev.
Those fields are currently unused and must be removed. While there
I moved the comment for MAX_TAP_QUEUES to the right place.

Fixes: 635b8c8ecdd27142 (tap: Renaming tap related APIs, data structures, macros)
Signed-off-by: Girish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add extack to upper device linking

Add extack arg to netdev_upper_dev_link and netdev_master_upper_dev_link

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tap: Renaming tap related APIs, data structures, macros

Renaming tap related APIs, data structures and macros in tap.c from macvtap_.* to tap_.*

Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: Increase limit of macvtap queues

Macvtap should be compatible with tuntap for
maximum number of queues.

commit 'baf71c5c1f80d82e92924050a60b5baaf97e3094 (tuntap:
Increase the number of queues in tun.)' removes
the limitations and increases number of queues in tuntap.
Now, Its safe to increase number of queues in Macvtap as well.

This patch also modifies 'macvtap_del_queues' function
to avoid extra memory allocation in stack.

Changes from v1->v2 :
Michael S. Tsirkin, Jason Wang :
Better way to use linked list to
avoid use of extra memory in stack.
Sergei Shtylyov : Specify dependent commit's summary.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: add source mode

This patch adds a new mode of operation to macvlan, called "source".
It allows one to set a list of allowed mac address, which is used
to match against source mac address from received frames on underlying
interface.
This enables creating mac based VLAN associations, instead of standard
port or tag based. The feature is useful to deploy 802.1x mac based
behavior, where drivers of underlying interfaces doesn't allows that.

Configuration is done through the netlink interface using e.g.:
ip link add link eth0 name macvlan0 type macvlan mode source
ip link add link eth0 name macvlan1 type macvlan mode source
ip link set link dev macvlan0 type macvlan macaddr add 00:11:11:11:11:11
ip link set link dev macvlan0 type macvlan macaddr add 00:22:22:22:22:22
ip link set link dev macvlan0 type macvlan macaddr add 00:33:33:33:33:33
ip link set link dev macvlan1 type macvlan macaddr add 00:33:33:33:33:33
ip link set link dev macvlan1 type macvlan macaddr add 00:44:44:44:44:44

This allows clients with MAC addresses 00:11:11:11:11:11,
00:22:22:22:22:22 to be part of only VLAN associated with macvlan0
interface. Clients with MAC addresses 00:44:44:44:44:44 with only VLAN
associated with macvlan1 interface. And client with MAC address
00:33:33:33:33:33 to be associated with both VLANs.

Based on work of Stefan Gula <steweg@gmail.com>

v8: last version of Stefan Gula for Kernel 3.2.1
v9: rework onto linux-next 2014-03-12 by Michael Braun
add MACADDR_SET command, enable to configure mac for source mode
while creating interface
v10:
- reduce indention level
- rename source_list to source_entry
- use aligned 64bit ether address
- use hash_64 instead of addr[5]
v11:
- rebase for 3.14 / linux-next 20.04.2014
v12
- rebase for linux-next 2014-09-25

Signed-off-by: Michael Braun <michael-dev@fami-braun.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: add netpoll support

Add netpoll support to macvlan devices. Based on the netpoll support in the 802.1q vlan code.

Tested and macvlan could work well with netconsole.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: Fix lockdep warnings with stacked macvlan devices

Macvlan devices try to avoid stacking, but that's not always
successfull or even desired. As an example, the following
configuration is perefectly legal and valid:

eth0 <--- macvlan0 <---- vlan0.10 <--- macvlan1

However, this configuration produces the following lockdep
trace:
[ 115.620418] ======================================================
[ 115.620477] [ INFO: possible circular locking dependency detected ]
[ 115.620516] 3.15.0-rc1+ #24 Not tainted
[ 115.620540] -------------------------------------------------------
[ 115.620577] ip/1704 is trying to acquire lock:
[ 115.620604] (&vlan_netdev_addr_lock_key/1){+.....}, at: [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
[ 115.620686]
but task is already holding lock:
[ 115.620723] (&macvlan_netdev_addr_lock_key){+.....}, at: [<ffffffff815da5be>] dev_set_rx_mode+0x1e/0x40
[ 115.620795]
which lock already depends on the new lock.

[ 115.620853]
the existing dependency chain (in reverse order) is:
[ 115.620894]
-> #1 (&macvlan_netdev_addr_lock_key){+.....}:
[ 115.620935] [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
[ 115.620974] [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
[ 115.621019] [<ffffffffa07296c3>] vlan_dev_set_rx_mode+0x53/0x110 [8021q]
[ 115.621066] [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
[ 115.621105] [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
[ 115.621143] [<ffffffff815da6be>] __dev_open+0xde/0x140
[ 115.621174] [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
[ 115.621174] [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
[ 115.621174] [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
[ 115.621174] [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
[ 115.621174] [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
[ 115.621174] [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
[ 115.621174] [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
[ 115.621174] [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
[ 115.621174] [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
[ 115.621174] [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
[ 115.621174] [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
[ 115.621174] [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
[ 115.621174] [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
[ 115.621174] [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b
[ 115.621174]
-> #0 (&vlan_netdev_addr_lock_key/1){+.....}:
[ 115.621174] [<ffffffff810d4d43>] __lock_acquire+0x1773/0x1a60
[ 115.621174] [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
[ 115.621174] [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
[ 115.621174] [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
[ 115.621174] [<ffffffffa0696d2a>] macvlan_set_mac_lists+0xca/0x110 [macvlan]
[ 115.621174] [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
[ 115.621174] [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
[ 115.621174] [<ffffffff815da6be>] __dev_open+0xde/0x140
[ 115.621174] [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
[ 115.621174] [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
[ 115.621174] [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
[ 115.621174] [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
[ 115.621174] [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
[ 115.621174] [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
[ 115.621174] [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
[ 115.621174] [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
[ 115.621174] [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
[ 115.621174] [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
[ 115.621174] [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
[ 115.621174] [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
[ 115.621174] [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
[ 115.621174] [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b
[ 115.621174]
other info that might help us debug this:

[ 115.621174] Possible unsafe locking scenario:

[ 115.621174] CPU0 CPU1
[ 115.621174] ---- ----
[ 115.621174] lock(&macvlan_netdev_addr_lock_key);
[ 115.621174] lock(&vlan_netdev_addr_lock_key/1);
[ 115.621174] lock(&macvlan_netdev_addr_lock_key);
[ 115.621174] lock(&vlan_netdev_addr_lock_key/1);
[ 115.621174]
*** DEADLOCK ***

[ 115.621174] 2 locks held by ip/1704:
[ 115.621174] #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff815e6dbb>] rtnetlink_rcv+0x1b/0x40
[ 115.621174] #1: (&macvlan_netdev_addr_lock_key){+.....}, at: [<ffffffff815da5be>] dev_set_rx_mode+0x1e/0x40
[ 115.621174]
stack backtrace:
[ 115.621174] CPU: 3 PID: 1704 Comm: ip Not tainted 3.15.0-rc1+ #24
[ 115.621174] Hardware name: Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010
[ 115.621174] ffffffff82339ae0 ffff880465f79568 ffffffff816ee20c ffffffff82339ae0
[ 115.621174] ffff880465f795a8 ffffffff816e9e1b ffff880465f79600 ffff880465b019c8
[ 115.621174] 0000000000000001 0000000000000002 ffff880465b019c8 ffff880465b01230
[ 115.621174] Call Trace:
[ 115.621174] [<ffffffff816ee20c>] dump_stack+0x4d/0x66
[ 115.621174] [<ffffffff816e9e1b>] print_circular_bug+0x200/0x20e
[ 115.621174] [<ffffffff810d4d43>] __lock_acquire+0x1773/0x1a60
[ 115.621174] [<ffffffff810d3172>] ? trace_hardirqs_on_caller+0xb2/0x1d0
[ 115.621174] [<ffffffff810d57f2>] lock_acquire+0xa2/0x130
[ 115.621174] [<ffffffff815df49c>] ? dev_uc_sync+0x3c/0x80
[ 115.621174] [<ffffffff816f62e7>] _raw_spin_lock_nested+0x37/0x50
[ 115.621174] [<ffffffff815df49c>] ? dev_uc_sync+0x3c/0x80
[ 115.621174] [<ffffffff815df49c>] dev_uc_sync+0x3c/0x80
[ 115.621174] [<ffffffffa0696d2a>] macvlan_set_mac_lists+0xca/0x110 [macvlan]
[ 115.621174] [<ffffffff815da557>] __dev_set_rx_mode+0x57/0xa0
[ 115.621174] [<ffffffff815da5c6>] dev_set_rx_mode+0x26/0x40
[ 115.621174] [<ffffffff815da6be>] __dev_open+0xde/0x140
[ 115.621174] [<ffffffff815da9ad>] __dev_change_flags+0x9d/0x170
[ 115.621174] [<ffffffff815daaa9>] dev_change_flags+0x29/0x60
[ 115.621174] [<ffffffff811e1db1>] ? mem_cgroup_bad_page_check+0x21/0x30
[ 115.621174] [<ffffffff815e7f11>] do_setlink+0x321/0x9a0
[ 115.621174] [<ffffffff810d394c>] ? __lock_acquire+0x37c/0x1a60
[ 115.621174] [<ffffffff815ea59f>] rtnl_newlink+0x51f/0x730
[ 115.621174] [<ffffffff815ea169>] ? rtnl_newlink+0xe9/0x730
[ 115.621174] [<ffffffff815e6e75>] rtnetlink_rcv_msg+0x95/0x250
[ 115.621174] [<ffffffff810d329d>] ? trace_hardirqs_on+0xd/0x10
[ 115.621174] [<ffffffff815e6dbb>] ? rtnetlink_rcv+0x1b/0x40
[ 115.621174] [<ffffffff815e6de0>] ? rtnetlink_rcv+0x40/0x40
[ 115.621174] [<ffffffff81608b19>] netlink_rcv_skb+0xa9/0xc0
[ 115.621174] [<ffffffff815e6dca>] rtnetlink_rcv+0x2a/0x40
[ 115.621174] [<ffffffff81608150>] netlink_unicast+0xf0/0x1c0
[ 115.621174] [<ffffffff8160851f>] netlink_sendmsg+0x2ff/0x740
[ 115.621174] [<ffffffff815bc9db>] sock_sendmsg+0x8b/0xc0
[ 115.621174] [<ffffffff8119d4af>] ? might_fault+0x5f/0xb0
[ 115.621174] [<ffffffff8119d4f8>] ? might_fault+0xa8/0xb0
[ 115.621174] [<ffffffff8119d4af>] ? might_fault+0x5f/0xb0
[ 115.621174] [<ffffffff815cb51e>] ? verify_iovec+0x5e/0xe0
[ 115.621174] [<ffffffff815bd4b9>] ___sys_sendmsg+0x369/0x380
[ 115.621174] [<ffffffff816faa0d>] ? __do_page_fault+0x11d/0x570
[ 115.621174] [<ffffffff810cfe9f>] ? up_read+0x1f/0x40
[ 115.621174] [<ffffffff816fab04>] ? __do_page_fault+0x214/0x570
[ 115.621174] [<ffffffff8120a10b>] ? mntput_no_expire+0x6b/0x1c0
[ 115.621174] [<ffffffff8120a0b7>] ? mntput_no_expire+0x17/0x1c0
[ 115.621174] [<ffffffff8120a284>] ? mntput+0x24/0x40
[ 115.621174] [<ffffffff815bdbb2>] __sys_sendmsg+0x42/0x80
[ 115.621174] [<ffffffff815bdc02>] SyS_sendmsg+0x12/0x20
[ 115.621174] [<ffffffff816ffd69>] system_call_fastpath+0x16/0x1b

Fix this by correctly providing macvlan lockdep class.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: unify macvlan_pcpu_stats and vlan_pcpu_stats

They are same, so unify them as one; since macvlan is a kind of vlan,
vlan_pcpu_stats should be a proper name for vlan and macvlan.

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: make start_xmit local

Only used in one file, no need to expose

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: Remove custom recieve and forward handlers

Since now macvlan and macvtap use the same receive and
forward handlers, we can remove them completely and use
netif_rx and dev_forward_skb() directly.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: introduce macvlan_dev_real_dev() helper function

Introduce helper function macvlan_dev_real_dev which returns the
underlying device of a macvlan device, similar to vlan_dev_real_dev()
for 802.1q VLAN devices.

v2: IFF_MACVLAN flag and equivalent of is_macvlan_dev() were
introduced in the meantime

v3: do BUG() if compiled without macvlan support

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add layer 2 hardware acceleration operations for macvlan devices

Add a operations structure that allows a network interface to export
the fact that it supports package forwarding in hardware between
physical interfaces and other mac layer devices assigned to it (such
as macvlans). This operaions structure can be used by virtual mac
devices to bypass software switching so that forwarding can be done
in hardware more efficiently.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: Let TUNSETOFFLOAD actually controll offload features.

When the user issues TUNSETOFFLOAD ioctl, macvtap does not do
anything other then to verify arguments. This patch adds
functionality to allow users to actually control offload features.
NETIF_F_GSO and NETIF_F_GRO are always on, but the rest of the
features can be controlled.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: slient sparse warnings

This patch silents the following sparse warnings:

drivers/net/macvtap.c:98:9: warning: incorrect type in assignment (different
address spaces)
drivers/net/macvtap.c:98:9: expected struct macvtap_queue *<noident>
drivers/net/macvtap.c:98:9: got struct macvtap_queue [noderef]
<asn:4>*<noident>
drivers/net/macvtap.c:120:9: warning: incorrect type in assignment (different
address spaces)
drivers/net/macvtap.c:120:9: expected struct macvtap_queue *<noident>
drivers/net/macvtap.c:120:9: got struct macvtap_queue [noderef]
<asn:4>*<noident>
drivers/net/macvtap.c:151:22: error: incompatible types in comparison expression
(different address spaces)
drivers/net/macvtap.c:233:23: error: incompatible types in comparison expression
(different address spaces)
drivers/net/macvtap.c:243:23: error: incompatible types in comparison expression
(different address spaces)
drivers/net/macvtap.c:247:15: error: incompatible types in comparison expression
(different address spaces)
CC [M] drivers/net/macvtap.o
drivers/net/macvlan.c:232:24: error: incompatible types in comparison expression
(different address spaces)

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: add TUNSETQUEUE ioctl

This patch adds TUNSETQUEUE ioctl to let userspace can temporarily disable or
enable a queue of macvtap. This is used to be compatible at API layer of tuntap
to simplify the userspace to manage the queues. This is done through introducing
a linked list to track all taps while using vlan->taps array to only track
active taps.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: change the max number of queues to 16

Macvtap should be at least compatible with tap, so change the max number to 16.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: switch to use IS_ENABLED()

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: add multicast filter

Setting up IPv6 addresses on configurations with many macvlans
is not really working, as many multicast messages are dropped.

Add a multicast filter to macvlan to reduce the amount of cloned
skbs and overhead.

Successfully tested with 1024 macvlans on one ethernet device.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: add FDB bridge ops and macvlan flags

This adds FDB bridge ops to the macvlan device passthru mode.
Additionally a flags field was added and a NOPROMISC bit to
allow users to use passthru mode without the driver calling
dev_set_promiscuity(). The flags field is a u16 placed in a
4 byte hole (consuming 2 bytes) of the macvlan_dev struct.

We want to do this so that the macvlan driver or stack
above the macvlan driver does not have to process every
packet. For the use case where we know all the MAC addresses
of the endstations above us this works well.

This patch is a result of Roopa Prabhu's work. Follow up
patches are needed for VEPA and VEB macvlan modes.

v2: Change from distinct nopromisc mode to a flags field to
configure this. This avoids the tendency to add a new
mode every time we need some slightly different behavior.
v3: fix error in dev_set_promiscuity and add change and get
link attributes for flags.

CC: Roopa Prabhu <roprabhu@cisco.com>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: Fix the minor device number allocation

On systems that create and delete lots of dynamic devices the
31bit linux ifindex fails to fit in the 16bit macvtap minor,
resulting in unusable macvtap devices. I have systems running
automated tests that that hit this condition in just a few days.

Use a linux idr allocator to track which mavtap minor numbers
are available and and to track the association between macvtap
minor numbers and macvtap network devices.

Remove the unnecessary unneccessary check to see if the network
device we have found is indeed a macvtap device. With macvtap
specific data structures it is impossible to find any other
kind of networking device.

Increase the macvtap minor range from 65536 to the full 20 bits
that is supported by linux device numbers. It doesn't solve the
original problem but there is no penalty for a larger minor
device range.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: lockless tx path

macvlan is a stacked device, like tunnels. We should use the lockless
mechanism we are using in tunnels and loopback.

This patch completely removes locking in TX path.

tx stat counters are added into existing percpu stat structure, renamed
from rx_stats to pcpu_stats.

Note : this reverts commit 2c11455321f37 (macvlan: add multiqueue
capability)

Note : rx_errors converted to a 32bit counter, like tx_dropped, since
they dont need 64bit range.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Ben Greear <greearb@candelatech.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_macvlan.h: Remove unnecessary semicolons

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: Implement multiqueue for macvtap driver

Implement multiqueue facility for macvtap driver. The idea is that
a macvtap device can be opened multiple times and the fd's can be
used to register eg, as backend for vhost.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvtap: Limit packet queue length

Mark Wagner reported OOM symptoms when sending UDP traffic over
a macvtap link to a kvm receiver.

This appears to be caused by the fact that macvtap packet queues
are unlimited in length. This means that if the receiver can't
keep up with the rate of flow, then we will hit OOM. Of course
it gets worse if the OOM killer then decides to kill the receiver.

This patch imposes a cap on the packet queue length, in the same
way as the tuntap driver, using the device TX queue length.

Please note that macvtap currently has no way of giving congestion
notification, that means the software device TX queue cannot be
used and packets will always be dropped once the macvtap driver
queue fills up.

This shouldn't be a great problem for the scenario where macvtap
is used to feed a kvm receiver, as the traffic is most likely
external in origin so congestion notification can't be applied
anyway.

Of course, if anybody decides to complain about guest-to-guest
UDP packet loss down the track, then we may have to revisit this.

Incidentally, this patch also fixes a real memory leak when
macvtap_get_queue fails.

Chris Wright noticed that for this patch to work, we need a
non-zero TX queue length. This patch includes his work to change
the default macvtap TX queue length to 500.

Reported-by: Mark Wagner <mwagner@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: 64 bit rx counters

Use u64_stats_sync infrastructure to implement 64bit stats.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: replace hooks in __netif_receive_skb V5

What this patch does is it removes two receive frame hooks (for bridge and for
macvlan) from __netif_receive_skb. These are replaced them with a single
hook for both. It only supports one hook per device because it makes no
sense to do bridging and macvlan on the same device.

Then a network driver (of virtual netdev like macvlan or bridge) can register
an rx_handler for needed net device.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: adjust handle_macvlan to pass port struct to hook

Now there's null check here and also again in the hook. Looking at bridge bits
which are simmilar, port structure is rcu_dereferenced right away in
handle_bridge and passed to hook. Looks nicer.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/macvtap: add vhost support

This adds support for passing a macvtap file descriptor into
vhost-net, much like we already do for tun/tap.

Most of the new code is taken from the respective patch
in the tun driver and may get consolidated in the future.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

percpu: add __percpu sparse annotations to net drivers

Add __percpu sparse annotations to net drivers.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macvtap driver

In order to use macvlan with qemu and other tools that require
a tap file descriptor, the macvtap driver adds a small backend
with a character device with the same interface as the tun
driver, with a minimum set of features.

Macvtap interfaces are created in the same way as macvlan
interfaces using ip link, but the netif is just used as a
handle for configuration and accounting, while the data
goes through the chardev. Each macvtap interface has its
own character device, simplifying permission management
significantly over the generic tun/tap driver.

Cc: Patrick McHardy <kaber@trash.net>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: David S. Miller" <davem@davemloft.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Or Gerlitz <ogerlitz@voltaire.com>
Cc: netdev@vger.kernel.org
Cc: bridge@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan: allow multiple driver backends

This makes it possible to hook into the macvlan driver
from another kernel module. In particular, the goal is
to extend it with the macvtap backend that provides
a tun/tap compatible interface directly on the macvlan
device.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove "#ifdef __KERNEL__" checks from unexported headers

Remove the "#ifdef __KERNEL__" tests from unexported header files in
linux/include whose entire contents are wrapped in that preprocessor
test.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[NET]: Add macvlan driver

Add macvlan driver, which allows to create virtual ethernet devices
based on MAC address.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>