The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

Lastly, fix the following checkpatch warning:
CHECK: Prefer kernel type 'u8' over 'uint8_t'
#50: FILE: net/l2tp/l2tp_core.h:119:
+	uint8_t			priv[];	/* private data */

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: NJonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2020-02-27

mlx5 misc updates and minor cleanups:

1) Use per vport tables for mirroring
2) Improve log messages for SW steering (DR)
3) Add devlink fdb_large_groups parameter
4) E-Switch, Allow goto earlier chain
5) Don't allow forwarding between uplink representors
6) Add support for devlink-port in non-representors mode
7) Minor misc cleanups
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mptcp conflict was overlapping additions.

The SMC conflict was an additional and removal happening at the same
time.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code is self explanatory and makes the comment redundant.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Reviewed-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

mlx5e_tc_offload_to_slow_path() and mlx5e_tc_unoffload_from_slow_path()
take an extra argument allocated on the stack of the caller but not used
by the caller. Avoid the extra argument and use local variable in the
function itself.
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

parse_attr is not used by parse_tc_pedit_action() so revmove it.
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

This to be consistent and adds the module name to the error message.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Reviewed-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

This is for added netdev prefix that helps identify
the source of the message.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Reviewed-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

This helps identify the source of the message.
If netdev still doesn't exists use mlx5_core_warn().
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Reviewed-by: NVlad Buslov <vladbu@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Few print messages are in debug level where they should be in error, and
few messages are missing.
Signed-off-by: NErez Shitrit <erezsh@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Change matcher priority parameter type from u16 to u32,
this change is needed since sometimes upper levels
create a matcher with priority bigger than 2^16.
Signed-off-by: NHamdan Igbaria <hamdani@mellanox.com>
Reviewed-by: NAlex Vesker <valex@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Add a devlink parameter to control the number of large groups in a
autogrouped flow table. The default value is 15, and the range is between 1
and 1024.

The size of each large group can be calculated according to the following
formula: size = 4M / (fdb_large_groups + 1).

Examples:
- Set the number of large groups to 20.
    $ devlink dev param set pci/0000:82:00.0 name fdb_large_groups \
      cmode driverinit value 20

  Then run devlink reload command to apply the new value.
    $ devlink dev reload pci/0000:82:00.0

- Read the number of large groups in flow table.
    $ devlink dev param show pci/0000:82:00.0 name fdb_large_groups
    pci/0000:82:00.0:
      name fdb_large_groups type driver-specific
        values:
          cmode driverinit value 20
Signed-off-by: NJianbo Liu <jianbol@mellanox.com>
Reviewed-by: NVlad Buslov <vladbu@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

The prefix should be "MLX5_DEVLINK_PARAM_ID_" for all in
mlx5_devlink_param_id enum.
Signed-off-by: NJianbo Liu <jianbol@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Added devlink_port field to mlx5e_priv structure and a callback to
netdev ops to enable devlink to get info about the port. The port
registration happens at driver initialization.
Signed-off-by: NVladyslav Tarasiuk <vladyslavt@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Rename representor's mlx5e_get_devlink_port() to
mlx5e_rep_get_devlink_port().
The downstream patch will add a non-representor mlx5e function called
mlx5e_get_devlink_phy_port().
Signed-off-by: NVladyslav Tarasiuk <vladyslavt@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Mellanox FW can support this if ignore_flow_level capability exists.
Signed-off-by: NRoi Dayan <roid@mellanox.com>
Reviewed-by: NOz Shlomo <ozsh@mellanox.com>
Reviewed-by: NPaul Blakey <paulb@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

When using port mirroring, we forward the traffic to another table and
use that table to forward to the mirrored vport. Since the hardware
loses the values of reg c, and in particular reg c0, we fail the match
on the input vport which previously existed in reg c0. To overcome this
situation, we use a set of per vport tables, positioned at the lowest
priority, and forward traffic to those tables. Since these tables are
per vport, we can avoid matching on reg c0.

Fixes: c01cfd0f ("net/mlx5: E-Switch, Add match on vport metadata for rule in fast path")
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NMark Bloch <markb@mellanox.com>
Reviewed-by: NPaul Blakey <paulb@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

misc_params.source_port is a 16 bit field already so no need for
redundant masking against 0xffff. Also change local variables type to
u16.
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

We can install forwarding packets rule between uplink
in switchdev mode, as show below. But the hardware does
not do that as expected (mlnx_perf -i $PF1, we can't get
the counter of the PF1). By the way, if we add the uplink
PF0, PF1 to Open vSwitch and enable hw-offload, the rules
can be offloaded but not work fine too. This patch add a
check and if so return -EOPNOTSUPP.

$ tc filter add dev $PF0 protocol all parent ffff: prio 1 handle 1 \
    flower skip_sw action mirred egress redirect dev $PF1

$ tc -d -s filter show dev $PF0 ingress
    skip_sw
    in_hw in_hw_count 1
    action order 1: mirred (Egress Redirect to device enp130s0f1) stolen
    ...
    Sent hardware 408954 bytes 4173 pkt
    ...
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Pull networking fixes from David Miller:

 1) Fix leak in nl80211 AP start where we leak the ACL memory, from
    Johannes Berg.

 2) Fix double mutex unlock in mac80211, from Andrei Otcheretianski.

 3) Fix RCU stall in ipset, from Jozsef Kadlecsik.

 4) Fix devlink locking in devlink_dpipe_table_register, from Madhuparna
    Bhowmik.

 5) Fix race causing TX hang in ll_temac, from Esben Haabendal.

 6) Stale eth hdr pointer in br_dev_xmit(), from Nikolay Aleksandrov.

 7) Fix TX hash calculation bounds checking wrt. tc rules, from Amritha
    Nambiar.

 8) Size netlink responses properly in schedule action code to take into
    consideration TCA_ACT_FLAGS. From Jiri Pirko.

 9) Fix firmware paths for mscc PHY driver, from Antoine Tenart.

10) Don't register stmmac notifier multiple times, from Aaro Koskinen.

11) Various rmnet bug fixes, from Taehee Yoo.

12) Fix vsock deadlock in vsock transport release, from Stefano
    Garzarella.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (61 commits)
  net: dsa: mv88e6xxx: Fix masking of egress port
  mlxsw: pci: Wait longer before accessing the device after reset
  sfc: fix timestamp reconstruction at 16-bit rollover points
  vsock: fix potential deadlock in transport->release()
  unix: It's CONFIG_PROC_FS not CONFIG_PROCFS
  net: rmnet: fix packet forwarding in rmnet bridge mode
  net: rmnet: fix bridge mode bugs
  net: rmnet: use upper/lower device infrastructure
  net: rmnet: do not allow to change mux id if mux id is duplicated
  net: rmnet: remove rcu_read_lock in rmnet_force_unassociate_device()
  net: rmnet: fix suspicious RCU usage
  net: rmnet: fix NULL pointer dereference in rmnet_changelink()
  net: rmnet: fix NULL pointer dereference in rmnet_newlink()
  net: phy: marvell: don't interpret PHY status unless resolved
  mlx5: register lag notifier for init network namespace only
  unix: define and set show_fdinfo only if procfs is enabled
  hinic: fix a bug of rss configuration
  hinic: fix a bug of setting hw_ioctxt
  hinic: fix a irq affinity bug
  net/smc: check for valid ib_client_data
  ...

Add missing ~ to the usage of the mask.
Reported-by: NKevin Benson <Kevin.Benson@zii.aero>
Reported-by: NChris Healy <Chris.Healy@zii.aero>
Fixes: 5c74c54c ("net: dsa: mv88e6xxx: Split monitor port configuration")
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During initialization the driver issues a reset to the device and waits
for 100ms before checking if the firmware is ready. The waiting is
necessary because before that the device is irresponsive and the first
read can result in a completion timeout.

While 100ms is sufficient for Spectrum-1 and Spectrum-2, it is
insufficient for Spectrum-3.

Fix this by increasing the timeout to 200ms.

Fixes: da382875 ("mlxsw: spectrum: Extend to support Spectrum-3 ASIC")
Signed-off-by: NAmit Cohen <amitc@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are couple new values that PMTM register can return
in module_type field. Add them and map them to module width in
mlxsw_core_module_max_width(). Fix the existing names on the way.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can't just use the top bits of the last sync event as they could be
off-by-one every 65,536 seconds, giving an error in reconstruction of
65,536 seconds.

This patch uses the difference in the bottom 16 bits (mod 2^16) to
calculate an offset that needs to be applied to the last sync event to
get to the current time.
Signed-off-by: NAlexandru-Mihai Maftei <amaftei@solarflare.com>
Acked-by: NMartin Habets <mhabets@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some transports (hyperv, virtio) acquire the sock lock during the
.release() callback.

In the vsock_stream_connect() we call vsock_assign_transport(); if
the socket was previously assigned to another transport, the
vsk->transport->release() is called, but the sock lock is already
held in the vsock_stream_connect(), causing a deadlock reported by
syzbot:

    INFO: task syz-executor280:9768 blocked for more than 143 seconds.
      Not tainted 5.6.0-rc1-syzkaller #0
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    syz-executor280 D27912  9768   9766 0x00000000
    Call Trace:
     context_switch kernel/sched/core.c:3386 [inline]
     __schedule+0x934/0x1f90 kernel/sched/core.c:4082
     schedule+0xdc/0x2b0 kernel/sched/core.c:4156
     __lock_sock+0x165/0x290 net/core/sock.c:2413
     lock_sock_nested+0xfe/0x120 net/core/sock.c:2938
     virtio_transport_release+0xc4/0xd60 net/vmw_vsock/virtio_transport_common.c:832
     vsock_assign_transport+0xf3/0x3b0 net/vmw_vsock/af_vsock.c:454
     vsock_stream_connect+0x2b3/0xc70 net/vmw_vsock/af_vsock.c:1288
     __sys_connect_file+0x161/0x1c0 net/socket.c:1857
     __sys_connect+0x174/0x1b0 net/socket.c:1874
     __do_sys_connect net/socket.c:1885 [inline]
     __se_sys_connect net/socket.c:1882 [inline]
     __x64_sys_connect+0x73/0xb0 net/socket.c:1882
     do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
     entry_SYSCALL_64_after_hwframe+0x49/0xbe

To avoid this issue, this patch remove the lock acquiring in the
.release() callback of hyperv and virtio transports, and it holds
the lock when we call vsk->transport->release() in the vsock core.

Reported-by: syzbot+731710996d79d0d58fbc@syzkaller.appspotmail.com
Fixes: 408624af ("vsock: use local transport when it is loaded")
Signed-off-by: NStefano Garzarella <sgarzare@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Russell King says:

====================
rework phylink interface for split MAC/PCS support

The following series changes the phylink interface to allow us to
better support split MAC / MAC PCS setups.  The fundamental change
required for this turns out to be quite simple.

Today, mac_config() is used for everything to do with setting the
parameters for the MAC, and mac_link_up() is used to inform the
MAC driver that the link is now up (and so to allow packet flow.)
mac_config() also has had a few implementation issues, with folk
who believe that members such as "speed" and "duplex" are always
valid, where "link" gets used inappropriately, etc.

With the proposed patches, all this changes subtly - but in a
backwards compatible way at this stage.

We pass the the full resolved link state (speed, duplex, pause) to
mac_link_up(), and it is now guaranteed that these parameters to
this function will always be valid (no more SPEED_UNKNOWN or
DUPLEX_UNKNOWN here - unless phylink is fed with such things.)

Drivers should convert over to using the state in mac_link_up()
rather than configuring the speed, duplex and pause in the
mac_config() method. The patch series includes a number of MAC
drivers which I've thought have been easy targets - I've left the
remainder as I think they need maintainer input. However, *all*
drivers will need conversion for future phylink development.

v2: add ocelot/felix and qca/ar9331 DSA drivers to patch 2, add
  received tested-by so far.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the Marvell mvpp2 ethernet driver to use the finalised link
parameters in mac_link_up() rather than the parameters in mac_config().
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the Marvell mvneta ethernet driver to use the finalised link
parameters in mac_link_up() rather than the parameters in mac_config().
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the macb ethernet driver to use the finalised link
parameters in mac_link_up() rather than the parameters in mac_config().
Tested-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the DPAA2 ethernet driver to use the finalised link parameters
in mac_link_up() rather than the parameters in mac_config(), which are
more suited to the needs of the DPAA2 MC firmware than those available
via mac_config().
Tested-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the Xilinx AXI ethernet driver to use the finalised link
parameters in mac_link_up() rather than the parameters in mac_config().
Tested-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the resolved link configuration to set the MAC configuration when
mac_link_up() for non-internal-PHY ports.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Propagate the resolved link configuration down via DSA's
phylink_mac_link_up() operation to allow split PCS/MAC to work.
Tested-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Propagate the resolved link parameters via the mac_link_up() call for
MACs that do not automatically track their PCS state. We propagate the
link parameters via function arguments so that inappropriate members
of struct phylink_link_state can't be accessed, and creating a new
structure just for this adds needless complexity to the API.
Tested-by: NAndre Przywara <andre.przywara@arm.com>
Tested-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: 3a12500e ("unix: define and set show_fdinfo only if procfs is enabled")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Taehee Yoo says:

====================
net: rmnet: fix several bugs

This patchset is to fix several bugs in RMNET module.

1. The first patch fixes NULL-ptr-deref in rmnet_newlink().
When rmnet interface is being created, it uses IFLA_LINK
without checking NULL.
So, if userspace doesn't set IFLA_LINK, panic will occur.
In this patch, checking NULL pointer code is added.

2. The second patch fixes NULL-ptr-deref in rmnet_changelink().
To get real device in rmnet_changelink(), it uses IFLA_LINK.
But, IFLA_LINK should not be used in rmnet_changelink().

3. The third patch fixes suspicious RCU usage in rmnet_get_port().
rmnet_get_port() uses rcu_dereference_rtnl().
But, rmnet_get_port() is used by datapath.
So, rcu_dereference_bh() should be used instead of rcu_dereference_rtnl().

4. The fourth patch fixes suspicious RCU usage in
rmnet_force_unassociate_device().
RCU critical section should not be scheduled.
But, unregister_netdevice_queue() in the rmnet_force_unassociate_device()
would be scheduled.
So, the RCU warning occurs.
In this patch, the rcu_read_lock() in the rmnet_force_unassociate_device()
is removed because it's unnecessary.

5. The fifth patch fixes duplicate MUX ID case.
RMNET MUX ID is unique.
So, rmnet interface isn't allowed to be created, which have
a duplicate MUX ID.
But, only rmnet_newlink() checks this condition, rmnet_changelink()
doesn't check this.
So, duplicate MUX ID case would happen.

6. The sixth patch fixes upper/lower interface relationship problems.
When IFLA_LINK is used, the upper/lower infrastructure should be used.
Because it checks the maximum depth of upper/lower interfaces and it also
checks circular interface relationship, etc.
In this patch, netdev_upper_dev_link() is used.

7. The seventh patch fixes bridge related problems.
a) ->ndo_del_slave() doesn't work.
b) It couldn't detect circular upper/lower interface relationship.
c) It couldn't prevent stack overflow because of too deep depth
of upper/lower interface
d) It doesn't check the number of lower interfaces.
e) Panics because of several reasons.
These problems are actually the same problem.
So, this patch fixes these problems.

8. The eighth patch fixes packet forwarding issue in bridge mode
Packet forwarding is not working in rmnet bridge mode.
Because when a packet is forwarded, skb_push() for an ethernet header
is needed. But it doesn't call skb_push().
So, the ethernet header will be lost.

Change log:
 - update commit logs.
 - drop two patches in this patchset because of wrong target branch.
   - ("net: rmnet: add missing module alias")
   - ("net: rmnet: print error message when command fails")
 - remove unneessary rcu_read_lock() in the third patch.
 - use rcu_dereference_bh() instead of rcu_dereference in third patch.
 - do not allow to add a bridge device if rmnet interface is already
   bridge mode in the seventh patch.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>