- Perform dumpspec traversals for calculating size and populating the
  dump.
- Initially, wrap all spec TLVs in dump error TLVs (changed by later
  patches in the series).
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

- Use a TLV structure, with the typed chunks aligned to 8-byte sizes.
- Dump numeric fields as big-endian.
- Prolog contains the dump level.
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Load the TLV-based binary specification of what needs to be included in
a dump, from the "_abi_dump_spec" rtsymbol. If the symbol is not defined,
then dumps for levels >= 1 are not supported.
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

- Skeleton code to perform a binary debug dump via ethtoolops
  "set_dump", "get_dump_flags" and "get_dump_data", i.e. the ethtool
  -W/w mechanism.
- Skeleton functions for debugdump operations provided.
- An integer "dump level" can be specified, this is stored between
  ethtool invocations. Dump level 0 is still the "arm.diag" resource for
  backward compatibility. Other dump levels each define a set of state
  information to include in the dump, driven by a spec from FW.
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Both Eric and Paolo noticed the rcu_barrier() we use in
tcf_block_put_ext() could be a performance bottleneck when
we have a lot of tc classes.

Paolo provided the following to demonstrate the issue:

tc qdisc add dev lo root htb
for I in `seq 1 1000`; do
        tc class add dev lo parent 1: classid 1:$I htb rate 100kbit
        tc qdisc add dev lo parent 1:$I handle $((I + 1)): htb
        for J in `seq 1 10`; do
                tc filter add dev lo parent $((I + 1)): u32 match ip src 1.1.1.$J
        done
done
time tc qdisc del dev root

real    0m54.764s
user    0m0.023s
sys     0m0.000s

The rcu_barrier() there is to ensure we free the block after all chains
are gone, that is, to queue tcf_block_put_final() at the tail of workqueue.
We can achieve this ordering requirement by refcnt'ing tcf block instead,
that is, the tcf block is freed only when the last chain in this block is
gone. This also simplifies the code.

Paolo reported after this patch we get:

real    0m0.017s
user    0m0.000s
sys     0m0.017s
Tested-by: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'ieee802154-for-davem-2017-12-04' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan-next

Stefan Schmidt says:

====================
pull-request: ieee802154-next 2017-12-04

Some update from ieee802154 to *net-next*

Jian-Hong Pan updated our docs to match the APIs in code.
Michael Hennerichs enhanced the adf7242 driver to work with adf7241
devices and reworked the IRQ and packet handling in the driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Functions nsim_bpf_create_prog and nsim_bpf_destroy_prog are local to the
source and do not need to be in global scope, so make them static.

Cleans up sparse warnings:
symbol 'nsim_bpf_create_prog' was not declared. Should it be static?
symbol 'nsim_bpf_destroy_prog' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Geert Uytterhoeven says:

====================
Teach phylib hard-resetting devices

This patch series adds optional PHY reset support to phylib.

The first two patches are destined for David's net-next tree. They add
core PHY reset code, and update a driver that currently uses its own
reset code.

The last two patches are destined for Simon's renesas tree.  They add
properties to describe the EthernetAVB PHY reset topology to the common
Salvator-X/XS and ULCB DTS files, which solves two issues:
  1. On Salvator-XS, the enable pin of the regulator providing PHY power
     is connected to PRESETn, and PSCI powers down the SoC during system
     suspend.  Hence a PHY reset is needed to restore network
     functionality after system resume.
  2. Linux should not rely on the boot loader having reset the PHY, but
     should reset the PHY during driver probe.

Changes compared to v3:
  - Remove Florian's Acked-by,
  - Add missing #include <linux/gpio/consumer.h>,
  - Re-add the gpiod check, as the dummy gpiod_set_value() for !GPIOLIB
    does not ignore NULL, and calls WARN_ON(1),
  - Do not reassert the reset signal if {mdio,phy}_probe() or
    phy_device_register() succeeded, as that may destroy initial setup,
  - Do not deassert the reset signal in {mdio,phy}_remove(), as it
    should already be deasserted,
  - Bring the PHY back into reset state in phy_device_remove(),
  - Move/consolidate GPIO descriptor acquiring code from
    of_mdiobus_register_phy() and of_mdiobus_register_device() to
    mdiobus_register_device().
    Note that this changes behavior slightly, in that the reset signal
    is now also asserted when called from of_mdiobus_register_device().
  - Add Reviewed-by,

Changes compared to v2, as sent by Sergei Shtylyov:
  - Fix fwnode_get_named_gpiod() call due to added parameters (which
    allowed to eliminate the gpiod_direction_output() call),
  - Rebased, refreshed, reworded,
  - Take over from Sergei,
  - Add Acked-by,
  - Remove unneeded gpiod check, as gpiod_set_value() handles NULL fine,
  - Handle fwnode_get_named_gpiod() errors correctly:
      - -ENOENT is ignored (the GPIO is optional), and turned into NULL,
	which allowed to remove all later !IS_ERR() checks,
      - Other errors (incl. -EPROBE_DEFER) are propagated,
  - Extract DTS patches from series "[PATCH 0/4] ravb: Add PHY reset
    support" (https://www.spinics.net/lists/netdev/msg457308.html), and
    incorporate in this series, after moving reset-gpios from the
    ethernet to the ethernet-phy node.

Given (1) the new reset-gpios DT property in the PHY node follows
established practises, (2) the DT binding change in the first patch has
been acked by Rob, and (3) the DTS patch does not cause any regressions
if it is applied before the PHY driver patches, the DTS patches can be
applied independently.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

With the phylib now being aware of the "reset-gpios" PHY node property,
there should be no need to frob the PHY reset in this driver anymore...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

The PHY devices sometimes do have their reset signal (maybe even power
supply?) tied to some GPIO and sometimes it also does happen that a boot
loader does not leave it deasserted. So far this issue has been attacked
from (as I believe) a wrong angle: by teaching the MAC driver to manipulate
the GPIO in question; that solution, when applied to the device trees, led
to adding the PHY reset GPIO properties to the MAC device node, with one
exception: Cadence MACB driver which could handle the "reset-gpios" prop
in a PHY device subnode. I believe that the correct approach is to teach
the 'phylib' to get the MDIO device reset GPIO from the device tree node
corresponding to this device -- which this patch is doing...

Note that I had to modify the AT803x PHY driver as it would stop working
otherwise -- it made use of the reset GPIO for its own purposes...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Rob Herring <robh@kernel.org>
[geert: Propagate actual errors from fwnode_get_named_gpiod()]
[geert: Avoid destroying initial setup]
[geert: Consolidate GPIO descriptor acquiring code]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move dissection of tunnel info to outside of the main flow dissection
function, __skb_flow_dissect(). The sole user of this feature, the flower
classifier, is updated to call tunnel info dissection directly, using
skb_flow_dissect_tunnel_info().

This results in a slightly less complex implementation of
__skb_flow_dissect(), in particular removing logic from that call path
which is not used by the majority of users. The expense of this is borne by
the flower classifier which now has to make an extra call for tunnel info
dissection.

This patch should not result in any behavioural change.
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch introduces an eBPF based queue selection method. With this,
the policy could be offloaded to userspace completely through a new
ioctl TUNSETSTEERINGEBPF.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Salil Mehta says:

====================
net: hns3: Refactors "reset" handling code in HCLGE layer of HNS3 driver

This patch refactors the code of the reset feature in HCLGE layer
of HNS3 PF driver. Prime motivation to do this change is:
1. To reduce the time for which common miscellaneous Vector 0
   interrupt is disabled because of the reset. Simplification
   of the common miscellaneous interrupt handler routine(for
   Vector 0) used to handle reset and other sources of Vector
   0 interrupt.
2. Separate the task for handling the reset
3. Simplification of reset request submission and pending reset
   logic.

To achieve above below few things have been done:
1. Interrupt is disabled while common miscellaneous interrupt
   handler is entered and re-enabled before it is exit. This
   reduces the interrupt handling latency as compared to older
   interrupt handling scheme where interrupt was being disabled
   in interrupt handler context and re-enabled in task context
   some time later. Made Miscellaneous interrupt handler more
   generic to handle all sources including reset interrupt source.
2. New reset service task has been introduced to service the
   reset handling.
3. Introduces new reset service task for honoring software reset
   requests like from network stack related to timeout and serving
   the pending reset request(to reset the driver and associated
   clients).

Change Log:
Patch V2: Addressed comment by Andrew Lunn
   Link: https://lkml.org/lkml/2017/12/1/366
Patch V1: Initial Submit
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In exisiting code, the way to detect if driver/client reset should
be executed or if hardware should be be soft resetted was overly
complex.

Existing code use to read the interrupt status register from task
context to figure out if the interrupt source event was reset and
then use clear the interrupt source for reset while waiting for the
hardware to finish the reset. This behaviour again was confusing
and overly complex in terms of the flow.

This patch simplifies the handling of the requested reset and the
pending reset(i.e. reset which have already been asserted by the
software and hardware has acknowledged back to driver that it is
processing the hardware reset through interrupt)
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: lipeng <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Existing common service task was being used to service the reset
requests. This patch tries to make the handling of reset cleaner
by separating task to handle the reset requests. This might in
turn help in adapting similar handling approach for other
interrupt events like mailbox, sharing vector 0 interrupt.
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: lipeng <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The reset interrupt event shares common miscellaneous interrupt
Vector 0. In the existing reset interrupt handling we disable
the Vector 0 interrupt in misc interrupt handler and re-enable
them later in context to common service task.

This also means other event sources like mailbox would also be
deferred or if the interrupt event was due to mailbox(which shall
be supported for VF soon), it could delay the reset handling.

This patch reorganizes the reset interrupt handling logic and
makes it more fair to other events.
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: lipeng <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Function gem_add_flow_filter called on line 2958 inside lock on line 2949
but uses GFP_KERNEL

Generated by: scripts/coccinelle/locks/call_kern.cocci

Fixes: ae8223de ("net: macb: Added support for RX filtering")
CC: Rafal Ozieblo <rafalo@cadence.com>
Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Russell King says:

====================
SFP/phylink updates

This series, which follows on from the fixes posted earlier, improves
the phylink/sfp support.  Changes included here are:

- Merge 802.3z and SGMII modes into one "in-band" mode, using the
  PHY_INTERFACE_MODE_xxx definition to determine which should be used.
  This allows more flexibility as more interface modes become
  available.

- Allow 2500base-X and 10GBASE-KR to be requested from SFP.

- Remove unused and unnecessary phylink_init_eee()

- Restart 802.3z autonegotiation when starting the network device to
  ensure that the negotiated parameters are always correct.  It has
  been observed on mvneta that this is not always the case without
  this change.

- Add kerneldoc documentation for phylink and sfp upstream facing APIs
  and link it in to the networking documentation.

- Resolve a sparse warning in sfp-bus.c

- Convert phylink/sfp to use fwnode rather than DT so that other firmware
  systems can take advantage of this - I have received a request for it
  to be usable with ACPI.  The exception to this is our interactions with
  phylib, as phylib itself does not yet support fwnode.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert phylink to fwnode, switching phylink_create() from taking a
device_node to taking a fwnode_handle. This will allow other firmware
systems to take advantage of sfp/phylink support.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert sfp-bus to use fwnode rather than device_node internally, so
we can support more than just device tree firmware.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/sfp-bus.c:298:13: warning: context imbalance in 'sfp_bus_release' - wrong count at exit
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add kernel-doc documentation for sfp kernel APIs, and link it into the
networking kapi documentation under "Network device support".
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add kernel-doc documentation for phylink kernel APIs, and link it into
the networking kapi documentation under "Network device support".
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Restart 802.3z negotiation when the net device is brought up to ensure
that the link partner has our current link modes.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

phylink_init_eee() serves no purpose, remove it.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for handling the faster 2.5G and 10G link modes when used
with SFP modules.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the handling of SGMII and 802.3z is now the same, combine the
MLO_AN_xxx constants into a single MLO_AN_INBAND, and use the PHY
interface mode to distinguish between Cisco SGMII and 802.3z.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code handling SGMII and 802.3z is essentially the same, except that
we assume 802.3z has no PHY.  Re-organise the code such that these cases
are merged, and exclude 802.3z mode from having a PHY attached.  This
results in the same link handling behaviour as before.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add and use phy_interface_mode_is_8023z() helper to identify the
interface modes that use 802.3z negotiation.  Use it in phylink's
phylink_mac_an_restart().
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Incorrect/missing annotations caused a few sparse warnings:

rtnetlink.c:155:15: incompatible types .. (different address spaces)
rtnetlink.c:157:23: incompatible types .. (different address spaces)
rtnetlink.c:185:15: incompatible types .. (different address spaces)
rtnetlink.c:285:15: incompatible types .. (different address spaces)
rtnetlink.c:317:9: incompatible types .. (different address spaces)
rtnetlink.c:3054:23: incompatible types .. (different address spaces)

no change in generated code.

Fixes: addf9b90 ("net: rtnetlink: use rcu to free rtnl message handlers")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Small overlapping change conflict ('net' changed a line,
'net-next' added a line right afterwards) in flexcan.c
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull virtio fixes from Michael Tsirkin:
 "virtio and qemu bugfixes

  A couple of bugfixes that just became ready"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_balloon: fix increment of vb->num_pfns in fill_balloon()
  virtio: release virtio index when fail to device_register
  fw_cfg: fix driver remove

Pull networking fixes from David Miller:

 1) Various TCP control block fixes, including one that crashes with
    SELinux, from David Ahern and Eric Dumazet.

 2) Fix ACK generation in rxrpc, from David Howells.

 3) ipvlan doesn't set the mark properly in the ipv4 route lookup key,
    from Gao Feng.

 4) SIT configuration doesn't take on the frag_off ipv4 field
    configuration properly, fix from Hangbin Liu.

 5) TSO can fail after device down/up on stmmac, fix from Lars Persson.

 6) Various bpftool fixes (mostly in JSON handling) from Quentin Monnet.

 7) Various SKB leak fixes in vhost/tun/tap (mostly observed as
    performance problems). From Wei Xu.

 8) mvpps's TX descriptors were not zero initialized, from Yan Markman.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (57 commits)
  tcp: use IPCB instead of TCP_SKB_CB in inet_exact_dif_match()
  tcp: add tcp_v4_fill_cb()/tcp_v4_restore_cb()
  rxrpc: Fix the MAINTAINERS record
  rxrpc: Use correct netns source in rxrpc_release_sock()
  liquidio: fix incorrect indentation of assignment statement
  stmmac: reset last TSO segment size after device open
  ipvlan: Add the skb->mark as flow4's member to lookup route
  s390/qeth: build max size GSO skbs on L2 devices
  s390/qeth: fix GSO throughput regression
  s390/qeth: fix thinko in IPv4 multicast address tracking
  tap: free skb if flags error
  tun: free skb in early errors
  vhost: fix skb leak in handle_rx()
  bnxt_en: Fix a variable scoping in bnxt_hwrm_do_send_msg()
  bnxt_en: fix dst/src fid for vxlan encap/decap actions
  bnxt_en: wildcard smac while creating tunnel decap filter
  bnxt_en: Need to unconditionally shut down RoCE in bnxt_shutdown
  phylink: ensure we take the link down when phylink_stop() is called
  sfp: warn about modules requiring address change sequence
  sfp: improve RX_LOS handling
  ...

The chip family of TILEPro and TILE-Gx was developed by Tilera, which
was eventually acquired by Mellanox.  The tile architecture was added to
the kernel in 2010 and first appeared in 2.6.36.

Now at Mellanox we are developing new chips based on the ARM64
architecture; our last TILE-Gx chip (the Gx72) was released in 2013, and
our customers using tile architecture products are not, as far as we
know, looking to upgrade to newer kernel releases.  In the absence of
someone in the community stepping up to take over maintainership, this
commit marks the architecture as orphaned.

Cc: Chris Metcalf <metcalf@alum.mit.edu>
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

convert remaining users of rtnl_register to rtnl_register_module
and un-export rtnl_register.
Requested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'linux-can-next-for-4.16-20171201' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2017-12-01

this is a pull request of 10 patches for net-next/master.

The first two patches are by Arnd Bergmann, they convert the peak_usb
from using "struct timeval" to "ktime_t". The error handling in the
vxcan driver is clean up by Markus Elfring's patch. Bhumika Goyal
contributes a patch for the c_can_pci driver to make the pci data const.
The six patches by Pankaj Bansal for the flexcan driver add LS1021A
support by making the endianness of the driver configurable by the
device tree.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf-next 2017-12-03

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Addition of a software model for BPF offloads in order to ease
   testing code changes in that area and make semantics more clear.
   This is implemented in a new driver called netdevsim, which can
   later also be extended for other offloads. SR-IOV support is added
   as well to netdevsim. BPF kernel selftests for offloading are
   added so we can track basic functionality as well as exercising
   all corner cases around BPF offloading, from Jakub.

2) Today drivers have to drop the reference on BPF progs they hold
   due to XDP on device teardown themselves. Change this in order
   to make XDP handling inside the drivers less error prone, and
   move disabling XDP to the core instead, also from Jakub.

3) Misc set of BPF verifier improvements and cleanups as preparatory
   work for upcoming BPF-to-BPF calls. Among others, this set also
   improves liveness marking such that pruning can be slightly more
   effective. Register and stack liveness information is now included
   in the verifier log as well, from Alexei.

4) nfp JIT improvements in order to identify load/store sequences in
   the BPF prog e.g. coming from memcpy lowering and optimizing them
   through the NPU's command push pull (CPP) instruction, from Jiong.

5) Cleanups to test_cgrp2_attach2.c BPF sample code in oder to remove
   bpf_prog_attach() magic values and replacing them with actual proper
   attach flag instead, from David.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Westphal says:

====================
rtnetlink: rework handler (un)registering

Peter Zijlstra reported (referring to commit 019a3169,
"rtnetlink: add reference counting to prevent module unload while dump is in progress"):

 1) it not in fact a refcount, so using refcount_t is silly
 2) there is a distinct lack of memory barriers, so we can easily
    observe the decrement while the msg_handler is still in progress.
 3) waiting with a schedule()/yield() loop is complete crap and subject
    life-locks, imagine doing that rtnl_unregister_all() from a RT task.

In ancient times rtnetlink exposed a statically-sized table with
preset doit/dumpit handlers to be called for a protocol/type pair.

Later the rtnl_register interface was added and the table was allocated
on demand.  Eventually these were also used by modules.

Problem is that nothing prevents module unload while a netlink dump
is in progress.  netlink dumps can be span multiple recv calls and
netlink core saves the to-be-repeated dumper address for later invocation.

To prevent rmmod the netlink core expects callers to pass in the owning
module so a reference can be taken.

So far rtnetlink wasn't doing this, add new interface to pass THIS_MODULE.
Moreover, when converting parts of the rtnetlink handling to rcu this code
gained way too many READ_ONCE spots, remove them and the extra refcounting.

Take a module reference when running dumpit and doit callbacks
and never alter content of rtnl_link structures after they have been
published via rcu_assign_pointer.

Based partially on earlier patch from Peter.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This removes __rtnl_register and switches callers to either
rtnl_register or rtnl_register_module.

Also, rtnl_register() will now print an error if memory allocation
failed rather than panic the kernel.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

all of these can be compiled as a module, so use new
_module version to make sure module can no longer be removed
while callback/dump is in use.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>