Simon Wunderlich says:

====================
Here are two batman-adv bugfixes:

 - fix rx packet counters for local ARP replies, by Sven Eckelmann

 - fix memory leaks for unicast packetes received from another gateway
   in bridge loop avoidance, by Andreas Pape
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2017-06-13' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Some fixes:
 * Avi fixes some fallout from my mac80211 RX flags changes
 * Emmanuel fixes an issue with adhering to the spec, and
   an oversight in the SMPS management code
 * Jason's patch makes mac80211 use constant-time memory
   comparisons for message authentication, to avoid having
   potentially observable timing differences
 * my fix makes mac80211 set the basic rates bitmap before
   the channel so the next update to the driver has more
   consistent data - this required another rework patch to
   remove some useless 5/10 MHz code that can never be hit
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently when dumping a context data only word number '1' is read for the
entire context.

Fixes: c965db44 ("qed: Add support for debug data collection")
Signed-off-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A new Sierra Wireless EM7305 device ID used in a Toshiba laptop,
and two Longcheer device IDs entries used by Telewell TW-3G HSPA+
branded modems.
Reported-by: Petr Kloc <petr_kloc@yahoo.com>
Reported-by: Teemu Likonen <tlikonen@iki.fi>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

After commit 90eff909 ("net: phy: Allow splitting MDIO
bus/device support from PHYs") we could create a configuration where
MDIO_DEVICE=y and PHYLIB=m which leads to the following undefined
references:

 drivers/built-in.o: In function `thunder_mdiobus_pci_remove':
>> mdio-thunder.c:(.text+0x2a212f): undefined reference to
>> `mdiobus_unregister'
>> mdio-thunder.c:(.text+0x2a2138): undefined reference to
>> `mdiobus_free'
   drivers/built-in.o: In function `thunder_mdiobus_pci_probe':
   mdio-thunder.c:(.text+0x2a22e7): undefined reference to
`devm_mdiobus_alloc_size'
   mdio-thunder.c:(.text+0x2a236f): undefined reference to
`of_mdiobus_register'
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 90eff909 ("net: phy: Allow splitting MDIO bus/device support from PHYs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

It's already added by pr_fmt so remove the explicit use.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrey reported a use-after-free in add_grec():

        for (psf = *psf_list; psf; psf = psf_next) {
		...
                psf_next = psf->sf_next;

where the struct ip_sf_list's were already freed by:

 kfree+0xe8/0x2b0 mm/slub.c:3882
 ip_mc_clear_src+0x69/0x1c0 net/ipv4/igmp.c:2078
 ip_mc_dec_group+0x19a/0x470 net/ipv4/igmp.c:1618
 ip_mc_drop_socket+0x145/0x230 net/ipv4/igmp.c:2609
 inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:411
 sock_release+0x8d/0x1e0 net/socket.c:597
 sock_close+0x16/0x20 net/socket.c:1072

This happens because we don't hold pmc->lock in ip_mc_clear_src()
and a parallel mr_ifc_timer timer could jump in and access them.

The RCU lock is there but it is merely for pmc itself, this
spinlock could actually ensure we don't access them in parallel.

Thanks to Eric and Long for discussion on this bug.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Getting the device version out of the driver really aids debugging.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes uninitialized symbol warning that
got introduced by the following commit
773fc8f6 ("net: rps: send out pending IPI's on CPU hotplug")
Signed-off-by: Ashwanth Goli <ashwanth@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211 allows to modify the SMPS state of an AP both,
when it is started, and after it has been started. Such a
change will trigger an action frame to all the peers that
are currently connected, and will be remembered so that
new peers will get notified as soon as they connect (since
the SMPS setting in the beacon may not be the right one).

This means that we need to remember the SMPS state
currently requested as well as the SMPS state that was
configured initially (and advertised in the beacon).
The former is bss->req_smps and the latter is
sdata->smps_mode.

Initially, the AP interface could only be started with
SMPS_OFF, which means that sdata->smps_mode was SMPS_OFF
always. Later, a nl80211 API was added to be able to start
an AP with a different AP mode. That code forgot to update
bss->req_smps and because of that, if the AP interface was
started with SMPS_DYNAMIC, we had:
   sdata->smps_mode = SMPS_DYNAMIC
   bss->req_smps = SMPS_OFF

That configuration made mac80211 think it needs to fire off
an action frame to any new station connecting to the AP in
order to let it know that the actual SMPS configuration is
SMPS_OFF.

Fix that by properly setting bss->req_smps in
ieee80211_start_ap.

Fixes: f6993174 ("mac80211: set smps_mode according to ap params")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Otherwise, we enable all sorts of forgeries via timing attack.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-wireless@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When mac80211 changes the channel, it also calls into the driver's
bss_info_changed() callback, e.g. with BSS_CHANGED_IDLE. The driver
may, like iwlwifi does, access more data from bss_info in that case
and iwlwifi accesses the basic_rates bitmap, but if changing from a
band with more (basic) rates to one with fewer, an out-of-bounds
access of the rate array may result.

While we can't avoid having invalid data at some point in time, we
can avoid having it while we call the driver - so set up all the
data before configuring the channel, and then apply it afterwards.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=195677Reported-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Tested-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Debugged-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

There's no need for the station MLME code to handle bitrates for 5
or 10 MHz channels when it can't ever create such a configuration.
Remove the unnecessary code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If the driver reports the rx timestamp at PLCP start, mac80211 can
only handle legacy encoding, but the code checks that the encoding
is not legacy. Fix this.

Fixes: da6a4352 ("mac80211: separate encoding/bandwidth from flags")
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When a peer sends a BAR frame with PM bit clear, we should
not modify its PM state as madated by the spec in
802.11-20012 10.2.1.2.

Cc: stable@vger.kernel.org
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

A recent commit to refactor the driver and remove the hw_disabled_flags
field accidentally introduced two regressions. First, we overwrote
pf->flags which removed various key flags including the MSI-X settings.

Additionally, it was intended that we have now two flags,
HW_ATR_EVICT_CAPABLE and HW_ATR_EVICT_ENABLED, but this was not done,
and we accidentally were mis-using HW_ATR_EVICT_CAPABLE everywhere.

This patch adds the missing piece, HW_ATR_EVICT_ENABLED, and safely
updates pf->flags instead of overwriting it.

Without this patch we will have many problems including disabling MSI-X
support, and we'll attempt to use HW ATR eviction on devices which do
not support it.

Fixes: 47994c11 ("i40e: remove hw_disabled_flags in favor of using separate flag bits", 2017-04-19)
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When HSR interface is setup using ip link command, an annoying warning
appears with the trace as below:-

[  203.019828] hsr_get_node: Non-HSR frame
[  203.019833] Modules linked in:
[  203.019848] CPU: 0 PID: 158 Comm: sd-resolve Tainted: G        W       4.12.0-rc3-00052-g9fa6bf70 #2
[  203.019853] Hardware name: Generic DRA74X (Flattened Device Tree)
[  203.019869] [<c0110280>] (unwind_backtrace) from [<c010c2f4>] (show_stack+0x10/0x14)
[  203.019880] [<c010c2f4>] (show_stack) from [<c04b9f64>] (dump_stack+0xac/0xe0)
[  203.019894] [<c04b9f64>] (dump_stack) from [<c01374e8>] (__warn+0xd8/0x104)
[  203.019907] [<c01374e8>] (__warn) from [<c0137548>] (warn_slowpath_fmt+0x34/0x44)
root@am57xx-evm:~# [  203.019921] [<c0137548>] (warn_slowpath_fmt) from [<c081126c>] (hsr_get_node+0x148/0x170)
[  203.019932] [<c081126c>] (hsr_get_node) from [<c0814240>] (hsr_forward_skb+0x110/0x7c0)
[  203.019942] [<c0814240>] (hsr_forward_skb) from [<c0811d64>] (hsr_dev_xmit+0x2c/0x34)
[  203.019954] [<c0811d64>] (hsr_dev_xmit) from [<c06c0828>] (dev_hard_start_xmit+0xc4/0x3bc)
[  203.019963] [<c06c0828>] (dev_hard_start_xmit) from [<c06c13d8>] (__dev_queue_xmit+0x7c4/0x98c)
[  203.019974] [<c06c13d8>] (__dev_queue_xmit) from [<c0782f54>] (ip6_finish_output2+0x330/0xc1c)
[  203.019983] [<c0782f54>] (ip6_finish_output2) from [<c0788f0c>] (ip6_output+0x58/0x454)
[  203.019994] [<c0788f0c>] (ip6_output) from [<c07b16cc>] (mld_sendpack+0x420/0x744)

As this is an expected path to hsr_get_node() with frame coming from
the master interface, add a check to ensure packet is not from the
master port and then warn.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reading /proc/net/snmp6 yields bogus values on 32 bit kernels.
Use "u64" instead of "unsigned long" in sizeof().

Fixes: 4a4857b1 ("proc: Reduce cache miss in snmp6_seq_show")
Signed-off-by: Christian Perle <christian.perle@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes two issues:

1) When forwarding on *,G mroutes that are in a vrf, the
kernel was dropping information about the actual incoming
interface when calling ip_mr_forward from ip_mr_input.
This caused ip_mr_forward to send the multicast packet
back out the incoming interface.  Fix this by
modifying ip_mr_forward to be handed the correctly
resolved dev.

2) When a unresolved cache entry is created we store
the incoming skb on the unresolved cache entry and
upon mroute resolution from the user space daemon,
we attempt to forward the packet.  Again we were
not resolving to the correct incoming device for
a vrf scenario, before calling ip_mr_forward.
Fix this by resolving to the correct interface
and calling ip_mr_forward with the result.

Fixes: e58e4159 ("net: Enable support for VRF with ipv4 multicast")
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox mlx5 fixes 2017-06-11

This series contains some fixes for the mlx5 core and netdev driver.

Please pull and let me know if there's any problem.

For -stable:
("net/mlx5e: Added BW check for DIM decision mechanism")              kernels >= 4.9
("net/mlx5e: Fix wrong indications in DIM due to counter wraparound") kernels >= 4.9
("net/mlx5: Remove several module events out of ethtool stats")       kernels >= 4.10
("net/mlx5: Enable 4K UAR only when page size is bigger than 4K")     kernels >= 4.11

*all patches apply with no issue on their -stable.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Netanel Belgazal says:

====================
Bugs fixes in ena ethernet driver

This patchset contains fixes for the bugs that were discovered so far.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

check_for_missing_tx_completions() is called from a timer
task and looking for lost tx packets.
The old implementation accumulate all the lost tx packets
and did not check if those packets were retrieved on a later stage.
This cause to a situation where the driver reset
the device for no reason.

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For the rare case where the device runs out of free rx buffer
descriptors (in case of pressure on kernel  memory),
and the napi handler continuously fail to refill new Rx descriptors
until device rx queue totally runs out of all free rx buffers
to post incoming packet, leading to a deadlock:
* The device won't send interrupts since all the new
Rx packets will be dropped.
* The napi handler won't try to allocate new Rx descriptors
since allocation is part of NAPI that's not being invoked any more

The fix involves detecting this scenario and rescheduling NAPI
(to refill buffers) by the keepalive/watchdog task.

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch also change the mapping functions to devm_ functions

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bug:
"Completion context is occupied" error printout will be noticed in
dmesg.
This error will cause the admin command to fail, which will lead to
an ena_probe() failure or a watchdog reset (depends on which admin
command failed).

Root cause:
__ena_com_submit_admin_cmd() is the function that submits new entries to
the admin queue.
The function have a check that makes sure the queue is not full and the
function does not override any outstanding command.
It uses head and tail indexes for this check.
The head is increased by ena_com_handle_admin_completion() which runs
from interrupt context, and the tail index is increased by the submit
function (the function is running under ->q_lock, so there is no risk
of multithread increment).
Each command is associated with a completion context. This context
allocated before call to __ena_com_submit_admin_cmd() and freed by
ena_com_wait_and_process_admin_cq_interrupts(), right after the command
was completed.

This can lead to a state where the head was increased, the check passed,
but the completion context is still in use.

Solution:
Use the atomic variable ->outstanding_cmds instead of using the head and
the tail indexes.
This variable is safe for use since it is bumped in get_comp_ctx() in
__ena_com_submit_admin_cmd() and is freed by comp_ctxt_release()

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixing a bug that the driver does not unmask the IO interrupts
in ndo_open():
occasionally, the MSI-X interrupt (for one or more IO queues)
can be masked when ndo_close() was called.
If that is followed by ndo open(),
then the MSI-X will be still masked so no interrupt
will be received by the driver.

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current flow to detect admin completion is:
while (command_not_completed) {
	if (timeout)
		error

	check_for_completion()
		sleep()
   }
So in case the sleep took more than the timeout
(in case the thread/workqueue was not scheduled due to higher priority
task or prolonged VMexit), the driver can detect a stall even if
the completion is present.

The fix changes the order of this function to first check for
completion and only after that check if the timeout expired.

Fixes: 1738cd3e ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the page size isn't bigger than 4K, there is no added value of enabling 4K
UAR feature in the Firmware.

Modified the condition of enabling the 4K UAR accordingly.

Fixes: f502d834 ("net/mlx5: Activate support for 4K UARs")
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

DIM (Dynamically-tuned Interrupt Moderation) is a mechanism designed for
changing the channel interrupt moderation values in order to reduce CPU
overhead for all traffic types.
Each iteration of the algorithm, DIM calculates the difference in
throughput, packet rate and interrupt rate from last iteration in order
to make a decision. DIM relies on counters for each metric. When these
counters get to their type's max value they wraparound. In this case
the delta between 'end' and 'start' samples is negative and when
translated to unsigned integers - very high. This results in a false
indication to the algorithm and might result in a wrong decision.

The fix calculates the 'distance' between 'end' and 'start' samples in a
cyclic way around the relevant type's max value. It can also be viewed as
an absolute value around the type's max value instead of around 0.

Testing show higher stability in DIM profile selection and no wraparound
issues.

Fixes: cb3c7fd4 ("net/mlx5e: Support adaptive RX coalescing")
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

DIM (Dynamically-tuned Interrupt Moderation) is a mechanism designed for
changing the channel interrupt moderation values in order to reduce CPU
overhead for all traffic types.
Until now only interrupt and packet rate were sampled.
We found a scenario on which we get a false indication since a change in
DIM caused more aggregation and reduced packet rate while increasing BW.

We now regard a change as succesfull iff:
current_BW > (prev_BW + threshold) or
current_BW ~= prev_BW and current_PR > (prev_PR + threshold) or
current_BW ~= prev_BW and current_PR ~= prev_PR and
    current_IR < (prev_IR - threshold)
Where BW = Bandwidth, PR = Packet rate and IR = Interrupt rate

Improvements (ConnectX-4Lx 25GbE, single RX queue, LRO off)
    --------------------------------------------------
    packet size | before[Mb/s] | after[Mb/s] | gain  |
    2B          | 343.4        | 359.4       |  4.5% |
    16B         | 2739.7       | 2814.8      |  2.7% |
    64B         | 9739         | 10185.3     |  4.5% |

Fixes: cb3c7fd4 ("net/mlx5e: Support adaptive RX coalescing")
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Remove the following module event counters out of ethtool stats. The
reason for removing these event counters is that these events do not
occur without techinician's intervention.
  module_pwr_budget_exd
  module_long_range
  module_no_eeprom
  module_enforce_part
  module_unknown_id
  module_unknown_status
  module_plug

Fixes: bedb7c90 ("net/mlx5e: Add port module event counters to ethtool stats")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

The issue is that when we get an assert we will stop polling the health
and thus we cant enter error state when we have a real health issue.

Fixes: fd76ee4d ('net/mlx5_core: Fix internal error detection conditions')
Signed-off-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Send vport number to the create flow table inner method instead of
ignoring the vport argument and sending always 0.

Fixes: b3ba5149 ('net/mlx5: Refactor create flow table method to accept underlay QP')
Signed-off-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Thomas Petazzoni says:

====================
net: mvpp2: driver fixes

As requested, here is a series of patches containing only bug fixes
for the mvpp2 driver. It is based on the latest "net" branch.

Changes since v1:

 - Fixed a build breakage that occurred when only PATCH 1 was only,
   and not later patches in the series. Was reported by the kbuild
   report on the first submission.

 - Added Tested-by from Marc Zyngier on PATCH 2.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

smp_processor_id() should not be used in migration-enabled contexts. We
originally thought it was OK in the specific situation of this driver,
but it was wrong, and calling smp_processor_id() in a migration-enabled
context prints a big fat warning when CONFIG_DEBUG_PREEMPT=y.

Therefore, this commit replaces the smp_processor_id() in
migration-enabled contexts by the appropriate get_cpu/put_cpu sections.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Fixes: a786841d ("net: mvpp2: handle register mapping and access for PPv2.2")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit removes the useless remove
mvpp2_bm_cookie_{build,pool_get} functions. All what
mvpp2_bm_cookie_build() was doing is compute a 32-bit value by
concatenating the pool number and the CPU number... only to get the pool
number re-extracted by mvpp2_bm_cookie_pool_get() later on.

Instead, just get the pool number directly from RX descriptor status,
and pass it to mvpp2_pool_refill() and mvpp2_rx_refill().

This has the added benefit of dropping a smp_processor_id() call in a
migration-enabled context, which is wrong, and is the original
motivation for making this change.

Fixes: 3f518509 ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The kernel may sleep under a rcu read lock in tipc_msg_reverse, and the
function call path is:
tipc_l2_rcv_msg (acquire the lock by rcu_read_lock)
  tipc_rcv
    tipc_sk_rcv
      tipc_msg_reverse
        pskb_expand_head(GFP_KERNEL) --> may sleep
tipc_node_broadcast
  tipc_node_xmit_skb
    tipc_node_xmit
      tipc_sk_rcv
        tipc_msg_reverse
          pskb_expand_head(GFP_KERNEL) --> may sleep

To fix it, "GFP_KERNEL" is replaced with "GFP_ATOMIC".
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>