Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2018-10-31

This series contains a various collection of fixes.

Miroslav Lichvar from Red Hat or should I say IBM now?  Updates the PHC
timecounter interval for igb so that it gets updated at least once
every 550 seconds.

Ngai-Mint provides a fix for fm10k to prevent a soft lockup or system
crash by adding a new condition to determine if the SM mailbox is in the
correct state before proceeding.

Jake provides several fm10k fixes, first one marks complier aborts as
non-fatal since on some platforms trigger machine check errors when the
compile aborts.  Added missing device ids to the in-kernel driver.  Due
to the recent fixes, bumped the driver version.

I (Jeff Kirsher) fixed a XFRM_ALGO dependency for both ixgbe and
ixgbevf.  This fix was based on the original work from Arnd Bergmann,
which only fixed ixgbe.

Mitch provides a fix for i40e/avf to update the status codes, which
resolves an issue between a mis-match between i40e and the iavf driver,
which also supports the ice LAN driver.

Radoslaw fixes the ixgbe where the driver is logging a message about
spoofed packets detected when the VF is re-started with a different MAC
address.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2018-11-01

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

The main changes are:

1) Fix tcp_bpf_recvmsg() to return -EAGAIN instead of 0 in non-blocking
   case when no data is available yet, from John.

2) Fix a compilation error in libbpf_attach_type_by_name() when compiled
   with clang 3.8, from Andrey.

3) Fix a partial copy of map pointer on scalar alu and remove id
   generation for RET_PTR_TO_MAP_VALUE return types, from Daniel.

4) Add unlimited memlock limit for kernel selftest's flow_dissector_load
   program, from Yonghong.

5) Fix ping for some BPF shell based kselftests where distro does not
   ship "ping -6" anymore, from Li.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
The series contains two fixes in BPF core and test cases. For details
please see individual patches. Thanks!
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Right now unprivileged tests are never executed as a BPF test run,
only loaded. Allow for running them as well so that we can check
the outcome and probe for regressions.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Add some more map related test cases to test_verifier kselftest
to improve test coverage. Summary: 1012 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

In the verifier there is no such semantics where registers with
PTR_TO_MAP_VALUE type have an id assigned to them. This is only
used in PTR_TO_MAP_VALUE_OR_NULL and later on nullified once the
test against NULL has been pattern matched and type transformed
into PTR_TO_MAP_VALUE.

Fixes: 3e6a4b3e ("bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Roman Gushchin <guro@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

ALU operations on pointers such as scalar_reg += map_value_ptr are
handled in adjust_ptr_min_max_vals(). Problem is however that map_ptr
and range in the register state share a union, so transferring state
through dst_reg->range = ptr_reg->range is just buggy as any new
map_ptr in the dst_reg is then truncated (or null) for subsequent
checks. Fix this by adding a raw member and use it for copying state
over to dst_reg.

Fixes: f1174f77 ("bpf/verifier: rework value tracking")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Edward Cree <ecree@solarflare.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Arnaldo Carvalho de Melo reported build error in libbpf when clang
version 3.8.1-24 (tags/RELEASE_381/final) is used:

libbpf.c:2201:36: error: comparison of constant -22 with expression of
type 'const enum bpf_attach_type' is always false
[-Werror,-Wtautological-constant-out-of-range-compare]
                if (section_names[i].attach_type == -EINVAL)
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~~~~~~
1 error generated.

Fix the error by keeping "is_attachable" property of a program in a
separate struct field instead of trying to use attach_type itself.

Fixes: 956b620f ("libbpf: Introduce libbpf_attach_type_by_name")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

ping binary on some distros doesn't support "ping -6" anymore.
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Ido Schimmel says:

====================
mlxsw: Enable minimum shaper on MC TCs

Petr says:

An MC-aware mode was introduced in commit 7b819530 ("mlxsw:
spectrum: Configure MC-aware mode on mlxsw ports"). In MC-aware mode,
BUM traffic gets a special treatment by being assigned to a separate set
of traffic classes 8..15. Pairs of TCs 0 and 8, 1 and 9, etc., are then
configured to strictly prioritize the lower-numbered ones. The intention
is to prevent BUM traffic from flooding the switch and push out all UC
traffic, which would otherwise happen, and instead give UC traffic
precedence.

However strictly prioritizing UC traffic has the effect that UC overload
pushes out all BUM traffic, such as legitimate ARP queries. These
packets are kept in queues for a while, but under sustained UC overload,
their lifetime eventually expires and these packets are dropped. That is
detrimental to network performance as well.

In this patchset, MC TCs (8..15) are configured with minimum shaper of
200Mbps (a minimum permitted value) to allow a trickle of necessary
control traffic to get through.

First in patch #1, the QEEC register is extended with fields necessary
to configure the minimum shaper.

In patch #2, minimum shaper is enabled on TCs 8..15.

In patches #3 and #4, first the MC-awareness test is tweaked to support
the minimum shaper, and then a new test is introduced to test that MC
traffic behaves well under UC overload.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In a previous patch, mlxsw was updated to configure a minimum bandwidth
allowance on MC TCs. Test that this indeed fixes the problem of UC
traffic overload pushing out all MC traffic.

Fixes: b5638d46 ("selftests: mlxsw: Add a test for UC behavior under MC flood")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the minimum shaper is now being enabled for MC TCs, it's
unreasonable to expect no UC traffic loss. Minimal min shaper value is
200Mbps, which is 20% of the 1Gbps that this test configures on egress.
To cover for glitches, tolerate up to 25% UC degradation under MC
overload.

Fixes: b5638d46 ("selftests: mlxsw: Add a test for UC behavior under MC flood")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

An MC-aware mode was introduced in commit 7b819530 ("mlxsw:
spectrum: Configure MC-aware mode on mlxsw ports"). In MC-aware mode,
BUM traffic gets a special treatment by being assigned to a separate set
of traffic classes 8..15. Pairs of TCs 0 and 8, 1 and 9, etc., are then
configured to strictly prioritize the lower-numbered ones. The intention
is to prevent BUM traffic from flooding the switch and push out all UC
traffic, which would otherwise happen, and instead give UC traffic
precedence.

However strictly prioritizing UC traffic has the effect that UC overload
pushes out all BUM traffic, such as legitimate ARP queries. These
packets are kept in queues for a while, but under sustained UC overload,
their lifetime eventually expires and these packets are dropped. That is
detrimental to network performance as well.

Therefore configure the MC TCs (8..15) with minimum shaper of 200Mbps (a
minimum permitted value) to allow a trickle of necessary control traffic
to get through.

Fixes: 7b819530 ("mlxsw: spectrum: Configure MC-aware mode on mlxsw ports")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add QEEC.mise (minimum shaper enable) and QEEC.min_shaper_rate to enable
configuration of minimum shaper.

Increase the QEEC length to 0x20 as well: that's the length that the
register has had for a long time now, but with the configurations that
mlxsw typically exercises, the firmware tolerated 0x1C-sized packets.
With mise=true however, FW rejects packets unless they have the full
required length.

Fixes: b9b7cee4 ("mlxsw: reg: Add QoS ETS Element Configuration register")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Huazhong Tan says:

====================
Bugfix for the HNS3 driver

This patch series include bugfix for the HNS3 ethernet
controller driver.

Change log:
V4->V5:
	Fixes comments from Joe Perches & Sergei Shtylyov
V3->V4:
	Fixes comments from Sergei Shtylyov
V2->V3:
	Fixes comments from Sergei Shtylyov
V1->V2:
	Fixes the compilation break reported by kbuild test robot
	http://patchwork.ozlabs.org/patch/989818/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Since hclgevf_reset_wait() is used to wait for the hardware to complete
the reset, it is not necessary to hold the rtnl_lock during
hclgevf_reset_wait(). So this patch releases the lock for the duration
of hclgevf_reset_wait().

Fixes: 6988eb2a ("net: hns3: Add support to reset the enet/ring mgmt layer")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since hclge_reset_wait() is used to wait for the hardware to complete
the reset, it is not necessary to hold the rtnl_lock during
hclge_reset_wait(). So this patch releases the lock for the duration
of hclge_reset_wait().

Fixes: 6d4fab39 ("net: hns3: Reset net device with rtnl_lock")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In a multi-core machine, the mailbox service and reset service
will be executed at the same time. The reset service will re-initialize
the command queue, before that, the mailbox handler can only get some
invalid messages.

The HCLGE_STATE_CMD_DISABLE flag means that the command queue is not
available and needs to be reinitialized. Therefore, when the mailbox
handler recognizes this flag, it should not process the command.

Fixes: dde1a86e ("net: hns3: Add mailbox support to PF driver")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are some functions that, when they fail to send the command,
need to return the corresponding error value to its caller.

Fixes: 46a3df9f ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Fixes: 681ec399 ("net: hns3: fix for vlan table lost problem when resetting")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When there is a PHY, the driver needs to complete some operations through
MDIO during reset reinitialization, so HCLGE_STATE_CMD_DISABLE is more
suitable than HCLGE_STATE_RST_HANDLING to prevent the MDIO operation from
being sent during the hardware reset.

Fixes: b50ae26c ("net: hns3: never send command queue message to IMP when reset)
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The HEAD pointer of the hardware command queue maybe equal to the command
queue's next_to_use in the driver, so that does not belong to the invalid
HEAD pointer, since the hardware may not process the command in time,
causing the HEAD pointer to be too late to update. The variables' name
in this function is unreadable, so give them a more readable one.

Fixes: 3ff50490 ("net: hns3: fix a dead loop in hclge_cmd_csq_clean")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It is not necessary to reset the queue in the hns3_uninit_all_ring(),
since the queue is stopped in the down operation, and will be reset
in the up operation. And the judgment of the HCLGE_STATE_RST_HANDLING
flag in the hclge_reset_tqp() is not correct, because we need to reset
tqp during pf reset, otherwise it may cause queue not being reset to
working state problem.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The spin lock of the command queue only need to be initialized once
when the driver initializes the command queue. It is not necessary to
initialize the spin lock when resetting. At the same time, the
modification of the queue member should be performed after acquiring
the lock.

Fixes: 3efb960f ("net: hns3: Refactor the initialization of command queue")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current driver supports handling two vector0 interrupts, reset and
mailbox. When the hardware reports an interrupt of another type of
interrupt source, if the driver does not process the interrupt, but
enables the interrupt, the hardware will repeatedly report the unknown
interrupt.

Therefore, the driver enables the vector0 interrupt after clearing the
known type of interrupt source. Other conditions are not enabled.

Fixes: cd8c5c26 ("net: hns3: Fix for hclge_reset running repeatly problem")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When hns3_get_ring_config()/hns3_queue_to_ring()/
hns3_get_vector_ring_chain() failed during resetting, the allocated
memory has not been freed before these three functions return. So
this patch adds error handler in these functions to fix it.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When hns3_nic_init_vector_data() fails to map ring to vector,
it should cancel the netif_napi_add() that has been successfully
done and then exits.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As shown by Dmitris, we need to use csum_block_add() instead of csum_add()
when adding the FCS contribution to skb csum.

Before 4.18 (more exactly commit 88078d98 "net: pskb_trim_rcsum()
and CHECKSUM_COMPLETE are friends"), the whole skb csum was thrown away,
so RXFCS changes were ignored.

Then before commit d55bef50 ("net: fix pskb_trim_rcsum_slow() with
odd trim offset") both mlx5 and pskb_trim_rcsum_slow() bugs were canceling
each other.

Now we fixed pskb_trim_rcsum_slow() we need to fix mlx5.

Note that this patch also rewrites mlx5e_get_fcs() to :

- Use skb_header_pointer() instead of reinventing it.
- Use __get_unaligned_cpu32() to avoid possible non aligned accesses
  as Dmitris pointed out.

Fixes: 902a5459 ("net/mlx5e: When RXFCS is set, add FCS data into checksum calculation")
Reported-by: Paweł Staszewski <pstaszewski@itcare.pl>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eran Ben Elisha <eranbe@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Dimitris Michailidis <dmichail@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Paweł Staszewski <pstaszewski@itcare.pl>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Tested-By: Maria Pasechnik <mariap@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The idx in vhost_vring_ioctl() was controlled by userspace, hence a
potential exploitation of the Spectre variant 1 vulnerability.

Fixing this by sanitizing idx before using it to index d->vqs.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix a warning from checkpatch.pl:'please no space before tabs'
in include/net/af_unix.h
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix a warning from checkpatch:
function definition argument 'struct sock *' should also have an
identifier name in include/net/af_unix.h.
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Trivial fix to spelling mistake in dev_err message
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This change resolves a driver bug where the driver is logging a
message that says "Spoofed packets detected". This can occur on the PF
(host) when a VF has VLAN+MACVLAN enabled and is re-started with a
different MAC address.

MAC and VLAN anti-spoofing filters are to be enabled together.
Signed-off-by: Radoslaw Tyl <radoslawx.tyl@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Acked-by: Piotr Skajewski <piotrx.skajewski@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Add a few new status code which will be used by the ice driver, and
rename a few to make them more consistent. Error code are mapped to
similar values as in i40e_status.h, so as to be compatible with older
VF drivers not using this status enum.
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Based on the original work from Arnd Bergmann.

When XFRM_ALGO is not enabled, the new ixgbe IPsec code produces a
link error:

drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.o: In function `ixgbe_ipsec_vf_add_sa':
ixgbe_ipsec.c:(.text+0x1266): undefined reference to `xfrm_aead_get_byname'

Simply selecting XFRM_ALGO from here causes circular dependencies, so
to fix it, we probably want this slightly more complex solution that is
similar to what other drivers with XFRM offload do:

A separate Kconfig symbol now controls whether we include the IPsec
offload code. To keep the old behavior, this is left as 'default y'. The
dependency in XFRM_OFFLOAD still causes a circular dependency but is
not actually needed because this symbol is not user visible, so removing
that dependency on top makes it all work.

CC: Arnd Bergmann <arnd@arndb.de>
CC: Shannon Nelson <shannon.nelson@oracle.com>
Fixes: eda0333a ("ixgbe: add VF IPsec management")
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>

The upstream and out-of-tree drivers are once again at comparable
functionality. It's been a while since we updated the upstream driver
version, so bump it now.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The device IDs for the Ethernet SDI Adapter devices were never added to
the upstream driver. The IDs are already in the pci.ids database, and
are supported by the out-of-tree driver.

Add the device IDs now, so that the upstream driver can recognize and
load these devices.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

VF drivers can trigger PCIe completer aborts any time they read a queue
that they don't own. Even in nominal circumstances, it is not possible
to prevent the VF driver from reading queues it doesn't own. VF drivers
may attempt to read queues it previously owned, but which it no longer
does due to a PF reset.

Normally these completer aborts aren't an issue. However, on some
platforms these trigger machine check errors. This is true even if we
lower their severity from fatal to non-fatal. Indeed, we already have
code for lowering the severity.

We could attempt to mask these errors conditionally around resets, which
is the most common time they would occur. However this would essentially
be a race between the PF and VF drivers, and we may still occasionally
see machine check exceptions on these strictly configured platforms.

Instead, mask the errors entirely any time we resume VFs. By doing so,
we prevent the completer aborts from being sent to the parent PCIe
device, and thus these strict platforms will not upgrade them into
machine check errors.

Additionally, we don't lose any information by masking these errors,
because we'll still report VFs which attempt to access queues via the
FUM_BAD_VF_QACCESS errors.

Without this change, on platforms where completer aborts cause machine
check exceptions, the VF reading queues it doesn't own could crash the
host system. Masking the completer abort prevents this, so we should
mask it for good, and not just around a PCIe reset. Otherwise malicious
or misconfigured VFs could cause the host system to crash.

Because we are masking the error entirely, there is little reason to
also keep setting the severity bit, so that code is also removed.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Current condition will always incorrectly report a full SM mailbox if an
IES API application is not running. Due to this, the
"fm10k_service_task" will be infinitely queued into the driver's
workqueue. This, in turn, will cause a "kworker" thread to report 100%
CPU utilization and might cause "soft lockup" events or system crashes.

To fix this issue, a new condition is added to determine if the SM
mailbox is in the correct state of FM10K_STATE_OPEN before proceeding.
In other words, an instance of the IES API must be running. If there is,
the remainder of the flow stays the same which is to determine if the SM
mailbox capacity has been exceeded or not and take appropriate action.
Signed-off-by: Ngai-Mint Kwan <ngai-mint.kwan@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The timecounter needs to be updated at least once per ~550 seconds in
order to avoid a 40-bit SYSTIM timestamp to be misinterpreted as an old
timestamp.

Since commit 500462a9 ("timers: Switch to a non-cascading wheel"),
scheduling of delayed work seems to be less accurate and a requested
delay of 540 seconds may actually be longer than 550 seconds. Shorten
the delay to 480 seconds to be sure the timecounter is updated in time.

This fixes an issue with HW timestamps on 82580/I350/I354 being off by
~1100 seconds for few seconds every ~9 minutes.

Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We return 0 in the case of a nonblocking socket that has no data
available. However, this is incorrect and may confuse applications.
After this patch we do the correct thing and return the error
EAGAIN.

Quoting return codes from recvmsg manpage,

EAGAIN or EWOULDBLOCK
 The socket is marked nonblocking and the receive operation would
 block, or a receive timeout had been set and the timeout expired
 before data was received.

Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>