AMT gateway interface should not receive unexpected query messages.
In order to drop unexpected query messages, it checks nonce.
And it also checks ready4 and ready6 variables to drop duplicated messages.

Fixes: cbc21dc1 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

AMT gateway interface should not receive unexpected advertisement messages.
In order to drop these packets, it should check nonce and amt->status.

Fixes: cbc21dc1 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

When AMT gateway starts sending a new request message, it should
regenerate the nonce variable.

Fixes: cbc21dc1 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

There are some data races in the amt module.
amt->ready4, amt->ready6, and amt->status can be accessed concurrently
without locks.
So, it uses READ_ONCE() and WRITE_ONCE().

Fixes: cbc21dc1 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

By the previous patch, amt gateway handlers are changed to worked by
a single thread.
So, most locks for gateway are not needed.
So, it removes.

Fixes: cbc21dc1 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

There are some synchronization issues(amt->status, amt->req_cnt, etc)
if the interface is in gateway mode because gateway message handlers
are processed concurrently.
This applies a work queue for processing these messages instead of
expanding the locking context.

So, the purposes of this patch are to fix exist race conditions and to make
gateway to be able to validate a gateway status more correctly.

When the AMT gateway interface is created, it tries to establish to relay.
The establishment step looks stateless, but it should be managed well.
In order to handle messages in the gateway, it saves the current
status(i.e. AMT_STATUS_XXX).
This patch makes gateway code to be worked with a single thread.

Now, all messages except the multicast are triggered(received or
delay expired), and these messages will be stored in the event
queue(amt->events).
Then, the single worker processes stored messages asynchronously one
by one.
The multicast data message type will be still processed immediately.

Now, amt->lock is only needed to access the event queue(amt->events)
if an interface is the gateway mode.

Fixes: cbc21dc1 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Add spi_device_id entries to silent SPI warnings.

Fixes: 5fa6863b ("spi: Check we have a spi_device_id for each DT compatible")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20220717135831.2492844-2-o.rempel@pengutronix.deSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Add spi_device_id entries to silent following warnings:
 SPI driver sja1105 has no spi_device_id for nxp,sja1105e
 SPI driver sja1105 has no spi_device_id for nxp,sja1105t
 SPI driver sja1105 has no spi_device_id for nxp,sja1105p
 SPI driver sja1105 has no spi_device_id for nxp,sja1105q
 SPI driver sja1105 has no spi_device_id for nxp,sja1105r
 SPI driver sja1105 has no spi_device_id for nxp,sja1105s
 SPI driver sja1105 has no spi_device_id for nxp,sja1110a
 SPI driver sja1105 has no spi_device_id for nxp,sja1110b
 SPI driver sja1105 has no spi_device_id for nxp,sja1110c
 SPI driver sja1105 has no spi_device_id for nxp,sja1110d

Fixes: 5fa6863b ("spi: Check we have a spi_device_id for each DT compatible")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220717135831.2492844-1-o.rempel@pengutronix.deSigned-off-by: Paolo Abeni <pabeni@redhat.com>

be_cmd_read_port_transceiver_data assumes that it is given a buffer that
is at least PAGE_DATA_LEN long, or twice that if the module supports SFF
8472. However, this is not always the case.

Fix this by passing the desired offset and length to
be_cmd_read_port_transceiver_data so that we only copy the bytes once.

Fixes: e36edd9d ("be2net: add ethtool "-m" option support")
Signed-off-by: Hristo Venev <hristo@venev.name>
Link: https://lore.kernel.org/r/20220716085134.6095-1-hristo@venev.nameSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Disable is done in stmmac_init_eee() on the event of MAC link down.
Since setting enable/disable EEE via ethtool will eventually trigger
a MAC down, removing this redunctant call in stmmac_ethtool.c to avoid
calling xpcs_config_eee() twice.

Fixes: d4aeaed8 ("net: stmmac: trigger PCS EEE to turn off on link down")
Signed-off-by: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Link: https://lore.kernel.org/r/20220715122402.1017470-1-vee.khee.wong@linux.intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Vladimir Oltean says:

====================
Fix 2 DSA issues with vlan_filtering_is_global

This patch set fixes 2 issues with vlan_filtering_is_global switches.

Both are regressions introduced by refactoring commit d0004a02
("net: dsa: remove the "dsa_to_port in a loop" antipattern from the
core"), which wasn't tested on a wide enough variety of switches.

Tested on the sja1105 driver.
====================

Link: https://lore.kernel.org/r/20220715151659.780544-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The "ds" iterator variable used in dsa_port_reset_vlan_filtering() ->
dsa_switch_for_each_port() overwrites the "dp" received as argument,
which is later used to call dsa_port_vlan_filtering() proper.

As a result, switches which do enter that code path (the ones with
vlan_filtering_is_global=true) will dereference an invalid dp in
dsa_port_reset_vlan_filtering() after leaving a VLAN-aware bridge.

Use a dedicated "other_dp" iterator variable to avoid this from
happening.

Fixes: d0004a02 ("net: dsa: remove the "dsa_to_port in a loop" antipattern from the core")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The blamed refactoring commit changed a "port" iterator with "other_dp",
but still looked at the slave_dev of the dp outside the loop, instead of
other_dp->slave from the loop.

As a result, dsa_port_vlan_filtering() would not call
dsa_slave_manage_vlan_filtering() except for the port in cause, and not
for all switch ports as expected.

Fixes: d0004a02 ("net: dsa: remove the "dsa_to_port in a loop" antipattern from the core")
Reported-by: Lucian Banu <Lucian.Banu@westermo.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

It is possible to disable VFs while the PF driver is processing requests
from the VF driver.  This can result in a panic.

BUG: unable to handle kernel paging request at 000000000000106c
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 8 PID: 0 Comm: swapper/8 Kdump: loaded Tainted: G I      --------- -
Hardware name: Dell Inc. PowerEdge R740/06WXJT, BIOS 2.8.2 08/27/2020
RIP: 0010:ixgbe_msg_task+0x4c8/0x1690 [ixgbe]
Code: 00 00 48 8d 04 40 48 c1 e0 05 89 7c 24 24 89 fd 48 89 44 24 10 83 ff
01 0f 84 b8 04 00 00 4c 8b 64 24 10 4d 03 a5 48 22 00 00 <41> 80 7c 24 4c
00 0f 84 8a 03 00 00 0f b7 c7 83 f8 08 0f 84 8f 0a
RSP: 0018:ffffb337869f8df8 EFLAGS: 00010002
RAX: 0000000000001020 RBX: 0000000000000000 RCX: 000000000000002b
RDX: 0000000000000002 RSI: 0000000000000008 RDI: 0000000000000006
RBP: 0000000000000006 R08: 0000000000000002 R09: 0000000000029780
R10: 00006957d8f42832 R11: 0000000000000000 R12: 0000000000001020
R13: ffff8a00e8978ac0 R14: 000000000000002b R15: ffff8a00e8979c80
FS:  0000000000000000(0000) GS:ffff8a07dfd00000(0000) knlGS:00000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000106c CR3: 0000000063e10004 CR4: 00000000007726e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <IRQ>
 ? ttwu_do_wakeup+0x19/0x140
 ? try_to_wake_up+0x1cd/0x550
 ? ixgbevf_update_xcast_mode+0x71/0xc0 [ixgbevf]
 ixgbe_msix_other+0x17e/0x310 [ixgbe]
 __handle_irq_event_percpu+0x40/0x180
 handle_irq_event_percpu+0x30/0x80
 handle_irq_event+0x36/0x53
 handle_edge_irq+0x82/0x190
 handle_irq+0x1c/0x30
 do_IRQ+0x49/0xd0
 common_interrupt+0xf/0xf

This can be eventually be reproduced with the following script:

while :
do
    echo 63 > /sys/class/net/<devname>/device/sriov_numvfs
    sleep 1
    echo 0 > /sys/class/net/<devname>/device/sriov_numvfs
    sleep 1
done

Add lock when disabling SR-IOV to prevent process VF mailbox communication.

Fixes: d773d131 ("ixgbe: Fix memory leak when SR-IOV VFs are direct assigned")
Signed-off-by: Piotr Skajewski <piotrx.skajewski@intel.com>
Tested-by: Marek Szlosek <marek.szlosek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20220715214456.2968711-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Fix an issue when driver incorrectly detects state
of recovery process and erroneously reinitializes interrupts,
which results in a kernel error and call trace message.

The issue was caused by a combination of two factors:
1. Assuming the EMP reset issued after completing
firmware recovery means the whole recovery process is complete.
2. Erroneous reinitialization of interrupt vector after detecting
the above mentioned EMP reset.

Fixes (1) by changing how recovery state change is detected
and (2) by adjusting the conditional expression to ensure using proper
interrupt reinitialization method, depending on the situation.

Fixes: 4ff0ee1a ("i40e: Introduce recovery mode support")
Signed-off-by: Dawid Lukwinski <dawid.lukwinski@intel.com>
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20220715214542.2968762-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In mtk_wed_tx_ring_setup(.., int idx, ..), idx is used as an index here
  struct mtk_wed_ring *ring = &dev->tx_ring[idx];

The bounds of idx are checked here
  BUG_ON(idx > ARRAY_SIZE(dev->tx_ring));

If idx is the size of the array, it will pass this check and overflow.
So change the check to >= .

Fixes: 804775df ("net: ethernet: mtk_eth_soc: add support for Wireless Ethernet Dispatch (WED)")
Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20220716214654.1540240-1-trix@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Horatiu Vultur says:

====================
net: lan966x: Fix issues with MAC table

The patch series fixes 2 issues:
- when an entry was forgotten the irq thread was holding a spin lock and then
  was talking also rtnl_lock.
- the access to the HW MAC table is indirect, so the access to the HW MAC
  table was not synchronized, which means that there could be race conditions.
====================

Link: https://lore.kernel.org/r/20220714194040.231651-1-horatiu.vultur@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When the SW bridge was trying to add/remove entries to/from HW, the
access to HW was not protected by any lock. In this way, it was
possible to have race conditions.
Fix this by using the lan966x->mac_lock to protect parallel access to HW
for this cases.

Fixes: 25ee9561 ("net: lan966x: More MAC table functionality")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The problem with this spin lock is that it was just protecting the list
of the MAC entries in SW and not also the access to the MAC entries in HW.
Because the access to HW is indirect, then it could happen to have race
conditions.
For example when SW introduced an entry in MAC table and the irq mac is
trying to read something from the MAC.
Update such that also the access to MAC entries in HW is protected by
this lock.

Fixes: 5ccd66e0 ("net: lan966x: add support for interrupts from analyzer")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

To remove an entry to the MAC table, it is required first to setup the
entry and then issue a command for the MAC to forget the entry.
So if it happens for two threads to remove simultaneously an entry
in MAC table then it would be a race condition.
Fix this by using lan966x->mac_lock to protect the HW access.

Fixes: e18aba89 ("net: lan966x: add mactable support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

To add an entry to the MAC table, it is required first to setup the
entry and then issue a command for the MAC to learn the entry.
So if it happens for two threads to add simultaneously an entry in MAC
table then it would be a race condition.
Fix this by using lan966x->mac_lock to protect the HW access.

Fixes: fc0c3fe7 ("net: lan966x: Add function lan966x_mac_ip_learn()")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When the HW deletes an entry in MAC table then it generates an
interrupt. The SW will go through it's own list of MAC entries and if it
is not found then it would notify the listeners about this. The problem
is that when the SW will go through it's own list it would take a spin
lock(lan966x->mac_lock) and when it notifies that the entry is deleted.
But to notify the listeners it taking the rtnl_lock which is illegal.

This is fixed by instead of notifying right away that the entry is
deleted, move the entry on a temp list and once, it checks all the
entries then just notify that the entries from temp list are deleted.

Fixes: 5ccd66e0 ("net: lan966x: add support for interrupts from analyzer")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Vladimir Oltean says:

====================
Update DSA documentation

These are some updates of dsa.rst, since it hasn't kept up with
development (in some cases, even since 2017). I've added Fixes: tags as
I thought was appropriate.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The blamed commit updated the way in which VLANs are handled at the
cross-chip notifier layer and didn't update the documentation to say
that. Fix it.

Fixes: 134ef238 ("net: dsa: add explicit support for host bridge VLANs")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Returning -EOPNOTSUPP does *NOT* mean anything special.

port_vlan_add() is actually called from 2 code paths, one is
vlan_vid_add() from 8021q module and the other is
br_switchdev_port_vlan_add() from switchdev.

The bridge has a wrapper __vlan_vid_add() which first tries via
switchdev, then if that returns -EOPNOTSUPP, tries again via the VLAN RX
filters in the 8021q module. But DSA doesn't distinguish between one
call path and the other when calling the driver's port_vlan_add(), so if
the driver returns -EOPNOTSUPP to switchdev, it also returns -EOPNOTSUPP
to the 8021q module. And the latter is a hard error.

port_fdb_add() is called from the deferred dsa_owq only, so obviously
its return code isn't propagated anywhere, and cannot be interpreted in
any way.

The return code from port_mdb_add() is propagated to the bridge, but
again, this doesn't do anything special when -EOPNOTSUPP is returned,
but rather, br_switchdev_mdb_notify() returns void.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Switchdev has changed radically from its initial implementation, and the
currently provided definition is incorrect and very confusing.

Rewrite it in light of what it actually does.

Fixes: 2bedde1a ("net: dsa: Move FDB dump implementation inside DSA")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The given definition for what VID 0 represents in the current
port_fdb_add and port_mdb_add is blatantly wrong. Delete it and explain
the concepts surrounding DSA's understanding of FDB isolation.

Fixes: c2693363 ("net: dsa: request drivers to perform FDB isolation")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This was deleted in 2017, stop documenting it.

Fixes: dc0cbff3 ("net: dsa: Remove redundant MDB dump support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This was deleted in 2017, delete the obsolete documentation.

Fixes: c069fcd8 ("net: dsa: Remove support for bypass bridge port attributes/vlan set")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We've changed the API through which we can offload the bridge TX
forwarding process. Update the documentation in light of the removal of
2 DSA switch ops.

Fixes: b079922b ("net: dsa: add a "tx_fwd_offload" argument to ->port_bridge_join")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The provided information about FDB flushing is not really up to date.
The DSA core automatically calls port_fast_age() when necessary, and
drivers should just implement that rather than hooking it to
port_bridge_leave, port_stp_state_set and others.

Fixes: 732f794c ("net: dsa: add port fast ageing")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These methods were added without being documented, fix that.

Fixes: fd292c18 ("net: dsa: tear down devlink port regions when tearing down the devlink port on error")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A teardown method was added to dsa_switch_ops without being documented.
Do so now.

Fixes: 5e3f847a ("net: dsa: Add teardown callback for drivers")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Support for changing the tagging protocol was added without this
operation being documented; do so now.

Fixes: 53da0eba ("net: dsa: allow changing the tag protocol via the "tagging" device attribute")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes were made to the prototype of get_tag_protocol without
describing at a high level what they are about. Update the documentation
to explain that.

Fixes: 5ed4e3eb ("net: dsa: Pass a port to get_tag_protocol()")
Fixes: 4d776482 ("net: dsa: Get information about stacked DSA protocol")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the blamed commit, the enum was turned into a function pointer and
also renamed. Update the documentation.

Fixes: 7b314362 ("net: dsa: Allow the DSA driver to indicate the tag protocol")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Document the changes that took place in the DSA core in the blamed
commit.

Fixes: 0650bf52 ("net: dsa: be compatible with masters which unregister on shutdown")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the blamed commit we don't have register_switch_driver() and
unregister_switch_driver() anymore. Additionally, the expected
dsa_register_switch() and dsa_unregister_switch() calls aren't
documented.

Update the probing section with the details of how things are currently
done.

Fixes: 93e86b3b ("net: dsa: Remove legacy probing support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kuniyuki Iwashima says:

====================
sysctl: Fix data-races around ipv4_net_table (Round 3).

This series fixes data-races around 21 knobs after
igmp_link_local_mcast_reports in ipv4_net_table.

These 4 knobs are skipped because they are safe.

  - tcp_congestion_control: Safe with RCU and xchg().
  - tcp_available_congestion_control: Read only.
  - tcp_allowed_congestion_control: Safe with RCU and spinlock().
  - tcp_fastopen_key: Safe with RCU and xchg()

So, round 4 will start with fib_multipath_use_neigh.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

While reading sysctl_tcp_fastopen_blackhole_timeout, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: cf1ef3f0 ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>