Similar to u32 filter, it is useful to know how many times
we reach each basic filter and how many times we pass the
ematch attached to it.

Sample output:

filter protocol arp pref 49152 basic chain 0
filter protocol arp pref 49152 basic chain 0 handle 0x1  (rule hit 3 success 3)
	action order 1: gact action pass
	 random type none pass val 0
	 index 1 ref 1 bind 1 installed 81 sec used 4 sec
	Action statistics:
	Sent 126 bytes 3 pkt (dropped 0, overlimits 0 requeues 0)
	backlog 0b 0p requeues 0

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dumps can read state of the NETLINK_F_STRICT_CHK flag from
a field in the callback structure.  For non-dump GET requests
we need a way to access the state of that flag from a socket.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since phy driver features became a link_mode bitmap, phy drivers that
don't have a list of features configured will cause the kernel to crash
when probed.

Prevent the phy driver from registering if the features field is missing.

Fixes: 719655a1 ("net: phy: Replace phy driver features u32 with link_mode bitmap")
Reported-by: NScott Wood <oss@buserror.net>
Signed-off-by: NCamelia Groza <camelia.groza@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are now several places where qdisc_tree_reduce_backlog() is called
with a negative number of packets (to signal an increase in number of
packets in the queue). Rather than rely on overflow behaviour, change the
function signature to use signed integers to communicate this usage to
people reading the code.
Signed-off-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add devlink health dump commands, in order to run an dump operation
over a specific reporter.

The supported operations are dump_get in order to get last saved
dump (if not exist, dump now) and dump_clear to clear last saved
dump.

It is expected from driver's callback for diagnose command to fill it
via the buffer descriptors API. Devlink will parse it and convert it to
netlink nla API in order to pass it to the user.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add devlink health diagnose command, in order to run a diagnose
operation over a specific reporter.

It is expected from driver's callback for diagnose command to fill it
via the buffer descriptors API. Devlink will parse it and convert it to
netlink nla API in order to pass it to the user.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add devlink health recover command to the uapi, in order to allow the user
to execute a recover operation over a specific reporter.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add devlink health set command, in order to set configuration parameters
for a specific reporter.
Supported parameters are:
- graceful_period: Time interval between auto recoveries (in msec)
- auto_recover: Determines if the devlink shall execute recover upon
		receiving error for the reporter
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add devlink health get command to provide reporter/s data for user space.
Add the ability to get data per reporter or dump data from all available
reporters.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Upon error discover, every driver can report it to the devlink health
mechanism via devlink_health_report function, using the appropriate
reporter registered to it. Driver can pass error specific context which
will be delivered to it as part of the dump / recovery callbacks.

Once an error is reported, devlink health will do the following actions:
* A log is being send to the kernel trace events buffer
* Health status and statistics are being updated for the reporter instance
* Object dump is being taken and stored at the reporter instance (as long
  as there is no other dump which is already stored)
* Auto recovery attempt is being done. depends on:
  - Auto Recovery configuration
  - Grace period vs. time since last recover
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Devlink health reporter is an instance for reporting, diagnosing and
recovering from run time errors discovered by the reporters.
Define it's data structure and supported operations.
In addition, expose devlink API to create and destroy a reporter.
Each devlink instance will hold it's own reporters list.

As part of the allocation, driver shall provide a set of callbacks which
will be used the devlink in order to handle health reports and user
commands related to this reporter. In addition, driver is entitled to
provide some priv pointer, which can be fetched from the reporter by
devlink_health_reporter_priv function.

For each reporter, devlink will hold a metadata of statistics,
buffers and status.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Devlink health buffer is a mechanism to pass descriptors between drivers
and devlink. The API allows the driver to add objects, object pair,
value array (nested attributes), value and name.

Driver can use this API to fill the buffers in a format which can be
translated by the devlink to the netlink message.

In order to fulfill it, an internal buffer descriptor is defined. This
will hold the data and metadata per each attribute and by used to pass
actual commands to the netlink.

This mechanism will be later used in devlink health for dump and diagnose
data store by the drivers.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: NMoshe Shemesh <moshe@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Although matchall always matches packets, however, it still
relies on a protocol match first. So it is still useful to have
such a counter for matchall. Of course, unlike u32, every time
we hit a matchall filter, it is always a success, so we don't
have to distinguish them.

Sample output:

filter protocol 802.1Q pref 100 matchall chain 0
filter protocol 802.1Q pref 100 matchall chain 0 handle 0x1
  not_in_hw (rule hit 10)
	action order 1: vlan  pop continue
	 index 1 ref 1 bind 1 installed 40 sec used 1 sec
	Action statistics:
	Sent 836 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
	backlog 0b 0p requeues 0
Reported-by: NMartin Olsson <martin.olsson+netdev@sentorsecurity.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Interrupts have been disabled in phy_stop() already. So we can remove
phy_stop_interrupts() and free the interrupt in phy_disconnect()
directly.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In certain cases, pskb_trim_rcsum() may change skb pointers.
Reinitialize header pointers afterwards to avoid potential
use-after-frees. Add a note in the documentation of
pskb_trim_rcsum(). Found by KASAN.
Signed-off-by: NRoss Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since tcp_mmap() is defined when CONFIG_MMU is set.
Signed-off-by: NYafang Shao <laoar.shao@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since recent changes to the phylib state machine state PHY_CHANGELINK
isn't used any longer. Therefore let's remove it.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove duplicated include.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NDenis Bolotin <dbolotin@marvell.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A follow-up patch will enable vetoing of FDB entries. Make it possible
to communicate details of why an FDB entry is not acceptable back to the
user.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are four sources of VXLAN switchdev notifier calls:

- the changelink() link operation, which already supports extack,
- ndo_fdb_add() which got extack support in a previous patch,
- FDB updates due to packet forwarding,
- and vxlan_fdb_replay().

Extend vxlan_fdb_switchdev_call_notifiers() to include extack in the
switchdev message that it sends, and propagate the argument upwards to
the callers. For the first two cases, pass in the extack gotten through
the operation. For case #3, pass in NULL.

To cover the last case, extend vxlan_fdb_replay() to take extack
argument, which might come from whatever operation necessitated the FDB
replay.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drivers may not be able to support certain FDB entries, and an error
code is insufficient to give clear hints as to the reasons of rejection.

In order to make it possible to communicate the rejection reason, extend
ndo_fdb_add() with an extack argument. Adapt the existing
implementations of ndo_fdb_add() to take the parameter (and ignore it).
Pass the extack parameter when invoking ndo_fdb_add() from rtnl_fdb_add().
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This introduces a new generic SOL_SOCKET-level socket option called
SO_BINDTOIFINDEX. It behaves similar to SO_BINDTODEVICE, but takes a
network interface index as argument, rather than the network interface
name.

User-space often refers to network-interfaces via their index, but has
to temporarily resolve it to a name for a call into SO_BINDTODEVICE.
This might pose problems when the network-device is renamed
asynchronously by other parts of the system. When this happens, the
SO_BINDTODEVICE might either fail, or worse, it might bind to the wrong
device.

In most cases user-space only ever operates on devices which they
either manage themselves, or otherwise have a guarantee that the device
name will not change (e.g., devices that are UP cannot be renamed).
However, particularly in libraries this guarantee is non-obvious and it
would be nice if that race-condition would simply not exist. It would
make it easier for those libraries to operate even in situations where
the device-name might change under the hood.

A real use-case that we recently hit is trying to start the network
stack early in the initrd but make it survive into the real system.
Existing distributions rename network-interfaces during the transition
from initrd into the real system. This, obviously, cannot affect
devices that are up and running (unless you also consider moving them
between network-namespaces). However, the network manager now has to
make sure its management engine for dormant devices will not run in
parallel to these renames. Particularly, when you offload operations
like DHCP into separate processes, these might setup their sockets
early, and thus have to resolve the device-name possibly running into
this race-condition.

By avoiding a call to resolve the device-name, we no longer depend on
the name and can run network setup of dormant devices in parallel to
the transition off the initrd. The SO_BINDTOIFINDEX ioctl plugs this
race.
Reviewed-by: NTom Gundersen <teg@jklm.no>
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes recvmsg() to be able to peek across multiple tls records.
Without this patch, the tls's selftests test case
'recv_peek_large_buf_mult_recs' fails. Each tls receive context now
maintains a 'rx_list' to retain incoming skb carrying tls records. If a
tls record needs to be retained e.g. for peek case or for the case when
the buffer passed to recvmsg() has a length smaller than decrypted
record length, then it is added to 'rx_list'. Additionally, records are
added in 'rx_list' if the crypto operation runs in async mode. The
records are dequeued from 'rx_list' after the decrypted data is consumed
by copying into the buffer passed to recvmsg(). In case, the MSG_PEEK
flag is used in recvmsg(), then records are not consumed or removed
from the 'rx_list'.
Signed-off-by: NVakul Garg <vakul.garg@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are already checking in phy_detach() that the PHY driver is of
generic kind (1G or 10G) and we are going to make use of that in the SFP
layer as well for 1000BaseT SFP modules, so expose helper functions to
return that information.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

b53 and mv88e6xxx support passing platform_data, and now that we have
split the platform_data portion from the main net/dsa.h header file,
include only the relevant parts.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of having net/dsa.h contain both the internal switch tree/driver
structures, split the relevant platform_data parts into
include/linux/platform_data/dsa.h and make that header be included by
net/dsa.h in order not to break any setup. A subsequent set of patches
will update code including net/dsa.h to include only the platform_data
header.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.

afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.

Fix this by:

 (1) Getting an extra ref for an asynchronous call for the call itself to
     hold.  This makes sure the call doesn't evaporate on us accidentally
     and will allow the call to be retained by the caller in a future
     patch.  The ref is released on leaving afs_make_call() or
     afs_wait_for_call_to_complete().

 (2) In the event of an error from rxrpc_kernel_send_data():

     (a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
     	 call has been aborted and ended.  This prevents
     	 afs_deliver_to_call() from doing anything with any notifications
     	 it gets.

     (b) Explicitly end the call immediately to prevent further callbacks.

     (c) Cancel any queued async_work and wait for the work if it's
     	 executing.  This allows us to be sure the race won't recur when we
     	 change the state.  We put the work queue's ref on the call if we
     	 managed to cancel it.

     (d) Put the call's ref that we got in (1).  This belongs to us as long
     	 as the call is in state AFS_CALL_CL_REQUESTING.

Fixes: 341f741f ("afs: Refcount the afs_call struct")
Signed-off-by: NDavid Howells <dhowells@redhat.com>

There is not currently way to infer the port number through sysfs that
is being used as the CPU port number. Overlay a ndo_get_phys_port_name()
operation onto the DSA master network device in order to retrieve that
information.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bcm87xx and micrel driver has PHYs which are missing the .features
value. Add them. The bcm87xx is a 10G FEC only PHY. Add the needed
features definition of this PHY.

Fixes: 719655a1 ("net: phy: Replace phy driver features u32 with link_mode bitmap")
Reported-by: NScott Wood <oss@buserror.net>
Reported-by: NCamelia Groza <camelia.groza@nxp.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As reported, the SPDX license id is not placed correctly and the variant
of the BSD License used should be specified.

Fixes: c1629257 ("dt-bindings: reset: Add bindings for the Meson-AXG SoC Reset Controller")
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRob Herring <robh@kernel.org>

A command line option is much more flexible than a config option and
the supporting code is small. Gets rid of #ifdefs in the code too...
Suggested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Commit 65cab850 ("net: Allow class-e address assignment via ifconfig
ioctl") modified the IN_BADCLASS macro a bit, but unfortunatly one too
many '(' characters were added to the line, making any code that used
it, not build properly.

Also, the macro now compares an unsigned with a signed value, which
isn't ok, so fix that up by making both types match properly.
Reported-by: NChristopher Ferris <cferris@google.com>
Fixes: 65cab850 ("net: Allow class-e address assignment via ifconfig ioctl")
Cc: Dave Taht <dave.taht@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The changes introduced to allow rxrpc calls to be retried creates an issue
when it comes to refcounting afs_call structs.  The problem is that when
rxrpc_send_data() queues the last packet for an asynchronous call, the
following sequence can occur:

 (1) The notify_end_tx callback is invoked which causes the state in the
     afs_call to be changed from AFS_CALL_CL_REQUESTING or
     AFS_CALL_SV_REPLYING.

 (2) afs_deliver_to_call() can then process event notifications from rxrpc
     on the async_work queue.

 (3) Delivery of events, such as an abort from the server, can cause the
     afs_call state to be changed to AFS_CALL_COMPLETE on async_work.

 (4) For an asynchronous call, afs_process_async_call() notes that the call
     is complete and tried to clean up all the refs on async_work.

 (5) rxrpc_send_data() might return the amount of data transferred
     (success) or an error - which could in turn reflect a local error or a
     received error.

Synchronising the clean up after rxrpc_kernel_send_data() returns an error
with the asynchronous cleanup is then tricky to get right.

Mostly revert commit c038a58c.  The two API
functions the original commit added aren't currently used.  This makes
rxrpc_kernel_send_data() always return successfully if it queued the data
it was given.

Note that this doesn't affect synchronous calls since their Rx notification
function merely pokes a wait queue and does not refcounting.  The
asynchronous call notification function *has* to do refcounting and pass a
ref over the work item to avoid the need to sync the workqueue in call
cleanup.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv4 routing tables are flushed in two cases:

1. In response to events in the netdev and inetaddr notification chains
2. When a network namespace is being dismantled

In both cases only routes associated with a dead nexthop group are
flushed. However, a nexthop group will only be marked as dead in case it
is populated with actual nexthops using a nexthop device. This is not
the case when the route in question is an error route (e.g.,
'blackhole', 'unreachable').

Therefore, when a network namespace is being dismantled such routes are
not flushed and leaked [1].

To reproduce:
# ip netns add blue
# ip -n blue route add unreachable 192.0.2.0/24
# ip netns del blue

Fix this by not skipping error routes that are not marked with
RTNH_F_DEAD when flushing the routing tables.

To prevent the flushing of such routes in case #1, add a parameter to
fib_table_flush() that indicates if the table is flushed as part of
namespace dismantle or not.

Note that this problem does not exist in IPv6 since error routes are
associated with the loopback device.

[1]
unreferenced object 0xffff888066650338 (size 56):
  comm "ip", pid 1206, jiffies 4294786063 (age 26.235s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 b0 1c 62 61 80 88 ff ff  ..........ba....
    e8 8b a1 64 80 88 ff ff 00 07 00 08 fe 00 00 00  ...d............
  backtrace:
    [<00000000856ed27d>] inet_rtm_newroute+0x129/0x220
    [<00000000fcdfc00a>] rtnetlink_rcv_msg+0x397/0xa20
    [<00000000cb85801a>] netlink_rcv_skb+0x132/0x380
    [<00000000ebc991d2>] netlink_unicast+0x4c0/0x690
    [<0000000014f62875>] netlink_sendmsg+0x929/0xe10
    [<00000000bac9d967>] sock_sendmsg+0xc8/0x110
    [<00000000223e6485>] ___sys_sendmsg+0x77a/0x8f0
    [<000000002e94f880>] __sys_sendmsg+0xf7/0x250
    [<00000000ccb1fa72>] do_syscall_64+0x14d/0x610
    [<00000000ffbe3dae>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [<000000003a8b605b>] 0xffffffffffffffff
unreferenced object 0xffff888061621c88 (size 48):
  comm "ip", pid 1206, jiffies 4294786063 (age 26.235s)
  hex dump (first 32 bytes):
    6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    6b 6b 6b 6b 6b 6b 6b 6b d8 8e 26 5f 80 88 ff ff  kkkkkkkk..&_....
  backtrace:
    [<00000000733609e3>] fib_table_insert+0x978/0x1500
    [<00000000856ed27d>] inet_rtm_newroute+0x129/0x220
    [<00000000fcdfc00a>] rtnetlink_rcv_msg+0x397/0xa20
    [<00000000cb85801a>] netlink_rcv_skb+0x132/0x380
    [<00000000ebc991d2>] netlink_unicast+0x4c0/0x690
    [<0000000014f62875>] netlink_sendmsg+0x929/0xe10
    [<00000000bac9d967>] sock_sendmsg+0xc8/0x110
    [<00000000223e6485>] ___sys_sendmsg+0x77a/0x8f0
    [<000000002e94f880>] __sys_sendmsg+0xf7/0x250
    [<00000000ccb1fa72>] do_syscall_64+0x14d/0x610
    [<00000000ffbe3dae>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [<000000003a8b605b>] 0xffffffffffffffff

Fixes: 8cced9ef ("[NETNS]: Enable routing configuration in non-initial namespace.")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some transports (e.g. virtio-ccw) implement virtio operations that
seem to be a simple read/write as something more involved that
cannot be done from an atomic context.

Give at least a hint about that.
Signed-off-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

- get_features has returned 64 bits since commit d0254773
  ("virtio: add support for 64 bit features.")
- properly mark all optional callbacks
Signed-off-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>

Commit 49e54187 ("ata: libahci_platform: comply to PHY framework") uses
the PHY_MODE_SATA, but that enum had not yet been added. This caused a
build failure for me, with today's linux.git.

Also, there is a potentially conflicting (mis-named) PHY_MODE_SATA, hiding
in the Marvell Berlin SATA PHY driver.

Fix the build by:

    1) Renaming Marvell's defined value to a more scoped name,
       in order to avoid any potential conflicts: PHY_BERLIN_MODE_SATA.

    2) Adding the missing enum, which was going to be added anyway as part
       of [1].

[1] https://lkml.kernel.org/r/20190108163124.6409-3-miquel.raynal@bootlin.com

Fixes: 49e54187 ("ata: libahci_platform: comply to PHY framework")
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Acked-by: NJens Axboe <axboe@kernel.dk>
Acked-by: NOlof Johansson <olof@lixom.net>
Cc: Grzegorz Jaszczyk <jaz@semihalf.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The bpfilter.ko module can be removed while functions of the bpfilter.ko
are executing. so panic can occurred. in order to protect that, locks can
be used. a bpfilter_lock protects routines in the
__bpfilter_process_sockopt() but it's not enough because __exit routine
can be executed concurrently.

Now, the bpfilter_umh can not run in parallel.
So, the module do not removed while it's being used and it do not
double-create UMH process.
The members of the umh_info and the bpfilter_umh_ops are protected by
the bpfilter_umh_ops.lock.

test commands:
   while :
   do
	iptables -I FORWARD -m string --string ap --algo kmp &
	modprobe -rv bpfilter &
   done

splat looks like:
[  298.623435] BUG: unable to handle kernel paging request at fffffbfff807440b
[  298.628512] #PF error: [normal kernel read fault]
[  298.633018] PGD 124327067 P4D 124327067 PUD 11c1a3067 PMD 119eb2067 PTE 0
[  298.638859] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  298.638859] CPU: 0 PID: 2997 Comm: iptables Not tainted 4.20.0+ #154
[  298.638859] RIP: 0010:__mutex_lock+0x6b9/0x16a0
[  298.638859] Code: c0 00 00 e8 89 82 ff ff 80 bd 8f fc ff ff 00 0f 85 d9 05 00 00 48 8b 85 80 fc ff ff 48 bf 00 00 00 00 00 fc ff df 48 c1 e8 03 <80> 3c 38 00 0f 85 1d 0e 00 00 48 8b 85 c8 fc ff ff 49 39 47 58 c6
[  298.638859] RSP: 0018:ffff88810e7777a0 EFLAGS: 00010202
[  298.638859] RAX: 1ffffffff807440b RBX: ffff888111bd4d80 RCX: 0000000000000000
[  298.638859] RDX: 1ffff110235ff806 RSI: ffff888111bd5538 RDI: dffffc0000000000
[  298.638859] RBP: ffff88810e777b30 R08: 0000000080000002 R09: 0000000000000000
[  298.638859] R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff168a42c
[  298.638859] R13: ffff888111bd4d80 R14: ffff8881040e9a05 R15: ffffffffc03a2000
[  298.638859] FS:  00007f39e3758700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
[  298.638859] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  298.638859] CR2: fffffbfff807440b CR3: 000000011243e000 CR4: 00000000001006f0
[  298.638859] Call Trace:
[  298.638859]  ? mutex_lock_io_nested+0x1560/0x1560
[  298.638859]  ? kasan_kmalloc+0xa0/0xd0
[  298.638859]  ? kmem_cache_alloc+0x1c2/0x260
[  298.638859]  ? __alloc_file+0x92/0x3c0
[  298.638859]  ? alloc_empty_file+0x43/0x120
[  298.638859]  ? alloc_file_pseudo+0x220/0x330
[  298.638859]  ? sock_alloc_file+0x39/0x160
[  298.638859]  ? __sys_socket+0x113/0x1d0
[  298.638859]  ? __x64_sys_socket+0x6f/0xb0
[  298.638859]  ? do_syscall_64+0x138/0x560
[  298.638859]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  298.638859]  ? __alloc_file+0x92/0x3c0
[  298.638859]  ? init_object+0x6b/0x80
[  298.638859]  ? cyc2ns_read_end+0x10/0x10
[  298.638859]  ? cyc2ns_read_end+0x10/0x10
[  298.638859]  ? hlock_class+0x140/0x140
[  298.638859]  ? sched_clock_local+0xd4/0x140
[  298.638859]  ? sched_clock_local+0xd4/0x140
[  298.638859]  ? check_flags.part.37+0x440/0x440
[  298.638859]  ? __lock_acquire+0x4f90/0x4f90
[  298.638859]  ? set_rq_offline.part.89+0x140/0x140
[ ... ]

Fixes: d2ba09c1 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bpfilter_umh will be stopped via __stop_umh() when the bpfilter
error occurred.
The bpfilter_umh() couldn't start again because there is no restart
routine.

The section of the bpfilter_umh_{start/end} is no longer .init.rodata
because these area should be reused in the restart routine. hence
the section name is changed to .bpfilter_umh.

The bpfilter_ops->start() is restart callback. it will be called when
bpfilter_umh is stopped.
The stop bit means bpfilter_umh is stopped. this bit is set by both
start and stop routine.

Before this patch,
Test commands:
   $ iptables -vnL
   $ kill -9 <pid of bpfilter_umh>
   $ iptables -vnL
   [  480.045136] bpfilter: write fail -32
   $ iptables -vnL

All iptables commands will fail.

After this patch,
Test commands:
   $ iptables -vnL
   $ kill -9 <pid of bpfilter_umh>
   $ iptables -vnL
   $ iptables -vnL

Now, all iptables commands will work.

Fixes: d2ba09c1 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now, UMH process is killed, do_exit() calls the umh_info->cleanup callback
to release members of the umh_info.
This patch makes bpfilter_umh's cleanup routine to use the
umh_info->cleanup callback.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>