The at803x driver contains a function, at803x_match_phy_id(), which
tests whether the PHY ID matches the value passed, comparing phy_id
with phydev->phy_id and testing all bits that in the driver's mask.

This is the same test that is used to match the driver, with phy_id
replaced with the driver specified ID, phydev->drv->phy_id.

Hence, we already know the value of the bits being tested if we look
at phydev->drv->phy_id directly, and we do not require a complicated
test to check them. Test directly against phydev->drv->phy_id instead.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Remove the (per netns) spinlock in favor of xchg() atomic operations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Link: https://lore.kernel.org/r/20210719101107.3203943-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Yonghong Song report:
The bpf selftest tc_bpf failed with latest bpf-next.
The following is the command to run and the result:
$ ./test_progs -n 132
[   40.947571] bpf_testmod: loading out-of-tree module taints kernel.
test_tc_bpf:PASS:test_tc_bpf__open_and_load 0 nsec
test_tc_bpf:PASS:bpf_tc_hook_create(BPF_TC_INGRESS) 0 nsec
test_tc_bpf:PASS:bpf_tc_hook_create invalid hook.attach_point 0 nsec
test_tc_bpf_basic:PASS:bpf_obj_get_info_by_fd 0 nsec
test_tc_bpf_basic:PASS:bpf_tc_attach 0 nsec
test_tc_bpf_basic:PASS:handle set 0 nsec
test_tc_bpf_basic:PASS:priority set 0 nsec
test_tc_bpf_basic:PASS:prog_id set 0 nsec
test_tc_bpf_basic:PASS:bpf_tc_attach replace mode 0 nsec
test_tc_bpf_basic:PASS:bpf_tc_query 0 nsec
test_tc_bpf_basic:PASS:handle set 0 nsec
test_tc_bpf_basic:PASS:priority set 0 nsec
test_tc_bpf_basic:PASS:prog_id set 0 nsec
libbpf: Kernel error message: Failed to send filter delete notification
test_tc_bpf_basic:FAIL:bpf_tc_detach unexpected error: -3 (errno 3)
test_tc_bpf:FAIL:test_tc_internal ingress unexpected error: -3 (errno 3)

The failure seems due to the commit
    cfdf0d9 ("rtnetlink: use nlmsg_notify() in rtnetlink_send()")

Deal with ESRCH error in nlmsg_notify() even the report variable is zero.

Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Link: https://lore.kernel.org/r/20210719051816.11762-1-yajun.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The last argument of phy_clear_bits_mmd(..., u16 val); is u16 and not
int, just inline the value into the function call arguments.

No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

I got below panic when doing fuzz test:

Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 4056 Comm: syz-executor.3 Tainted: G    B             5.14.0-rc1-00195-gcff5c4254439-dirty #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x7a/0x9b
panic+0x2cd/0x5af
end_report.cold+0x5a/0x5a
kasan_report+0xec/0x110
ip_check_mc_rcu+0x556/0x5d0
__mkroute_output+0x895/0x1740
ip_route_output_key_hash_rcu+0x2d0/0x1050
ip_route_output_key_hash+0x182/0x2e0
ip_route_output_flow+0x28/0x130
udp_sendmsg+0x165d/0x2280
udpv6_sendmsg+0x121e/0x24f0
inet6_sendmsg+0xf7/0x140
sock_sendmsg+0xe9/0x180
____sys_sendmsg+0x2b8/0x7a0
___sys_sendmsg+0xf0/0x160
__sys_sendmmsg+0x17e/0x3c0
__x64_sys_sendmmsg+0x9e/0x100
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x462eb9
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8
 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48>
 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3df5af1c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462eb9
RDX: 0000000000000312 RSI: 0000000020001700 RDI: 0000000000000007
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3df5af26bc
R13: 00000000004c372d R14: 0000000000700b10 R15: 00000000ffffffff

It is one use-after-free in ip_check_mc_rcu.
In ip_mc_del_src, the ip_sf_list of pmc has been freed under pmc->lock protection.
But access to ip_sf_list in ip_check_mc_rcu is not protected by the lock.

Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ronak Doshi says:

====================
vmxnet3: upgrade to version 6

vmxnet3 emulation has recently added several new features which includes
increase in queues supported, remove power of 2 limitation on queues,
add RSS for ESP IPv6, etc. This patch series extends the vmxnet3 driver
to leverage these new features.

Compatibility is maintained using existing vmxnet3 versioning mechanism as
follows:
- new features added to vmxnet3 emulation are associated with new vmxnet3
   version viz. vmxnet3 version 6.
- emulation advertises all the versions it supports to the driver.
- during initialization, vmxnet3 driver picks the highest version number
supported by both the emulation and the driver and configures emulation
to run at that version.

In particular, following changes are introduced:

Patch 1:
  This patch introduces utility macros for vmxnet3 version 6 comparison
  and updates Copyright information.

Patch 2:
  This patch adds support to increase maximum Tx/Rx queues from 8 to 32.

Patch 3:
  This patch removes the limitation of power of 2 on the queues.

Patch 4:
  Uses existing get_rss_hash_opts and set_rss_hash_opts methods to add
  support for ESP IPv6 RSS.

Patch 5:
  This patch reports correct RSS hash type based on the type of RSS
  performed.

Patch 6:
  This patch updates maximum configurable mtu to 9190.

Patch 7:
  With all vmxnet3 version 6 changes incorporated in the vmxnet3 driver,
  with this patch, the driver can configure emulation to run at vmxnet3
  version 6.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

With all vmxnet3 version 6 changes incorporated in the vmxnet3 driver,
the driver can configure emulation to run at vmxnet3 version 6, provided
the emulation advertises support for version 6.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch increases the maximum configurable mtu to 9190
to accommodate jumbo packets of overlay traffic.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As vmxnet3 supports IP/TCP/UDP RSS, this patch sets appropriate
hash type based on the type of RSS performed.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vmxnet3 version 4 added support for ESP RSS. However, only IPv4 was
supported. With vmxnet3 version 6, this patch enables RSS for ESP
IPv6 packets as well.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

With version 6, vmxnet3 relaxes the restriction on queues to
be power of two. This is helpful in cases (Edge VM) where
vcpus are less than 8 and device requires more than 4 queues.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, vmxnet3 supports maximum of 8 Tx/Rx queues. With increase
in number of vcpus on a VM, to achieve better performance and utilize
idle vcpus, we need to increase the max number of queues supported.

This patch enhances vmxnet3 to support maximum of 32 Tx/Rx queues.
Increasing the Rx queues also increases the probability of distrubuting
the traffic from different flows to different queues with RSS.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vmxnet3 is currently at version 4 and this patch initiates the
preparation to accommodate changes for upto version 6. Introduced
utility macros for vmxnet3 version 6 comparison and update Copyright
information.

Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, when userspace reads a datagram with a buffer that is
smaller than this datagram, the data will be truncated and only
part of it can be received by users. It doesn't seem right that
users don't know the datagram size and have to use a huge buffer
to read it to avoid the truncation.

This patch to fix it by keeping the skb in rcv queue until the
whole data is read by users. Only the last msg of the datagram
will be marked with MSG_EOR, just as TCP/SCTP does.

Note that this will work as above only when MSG_EOR is set in the
flags parameter of recvmsg(), so that it won't break any old user
applications.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nguy/next-queue

Tony Nguyen says:

====================
1GbE Intel Wired LAN Driver Updates 2021-07-16

Vinicius Costa Gomes says:

Add support for steering traffic to specific RX queues using Flex Filters.

As the name implies, Flex Filters are more flexible than using
Layer-2, VLAN or MAC address filters, one of the reasons is that they
allow "AND" operations more easily, e.g. when the user wants to steer
some traffic based on the source MAC address and the packet ethertype.

Future work include adding support for offloading tc-u32 filters to
the hardware.

The series is divided as follows:

Patch 1/5, add the low level primitives for configuring Flex filters.

Patch 2/5 and 3/5, allow ethtool to manage Flex filters.

Patch 4/5, when specifying filters that have multiple predicates, use
Flex filters.

Patch 5/5, Adds support for exposing the i225 LEDs using the LED subsystem.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Each i225 has three LEDs. Export them via the LED class framework.

Each LED is controllable via sysfs. Example:

$ cd /sys/class/leds/igc_led0
$ cat brightness      # Current Mode
$ cat max_brightness  # 15
$ echo 0 > brightness # Mode 0
$ echo 1 > brightness # Mode 1

The brightness field here reflects the different LED modes ranging
from 0 to 15.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Currently flex filters are only used for filters containing user data.
However, it makes sense to utilize them also for filters having
multiple conditions, because that's not supported by the driver at the
moment. Add it.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Allows Flex Filters to be installed.

The previous restriction to the types of filters that can be installed
can now be lifted.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Use the flex filter mechanism to extend the current ethtool filter
operations by intercoperating the user data. This allows to match
eight more bytes within a Ethernet frame in addition to macs, ether
types and vlan.

The matching pattern looks like this:

 * dest_mac [6]
 * src_mac [6]
 * tpid [2]
 * vlan tci [2]
 * ether type [2]
 * user data [8]

This can be used to match Profinet traffic classes by FrameID range.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

The Intel i225 NIC has the possibility to add flex filters which can
match up to the first 128 byte of a packet. These filters are useful
for all kind of packet matching. One particular use case is Profinet,
as the different traffic classes are distinguished by the frame id
range which cannot be matched by any other means.

Add code to configure and enable flex filters.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Implement Wake-on-LAN feature for 88X3310 and 88E2110.

This is done by enabling WoL interrupt and WoL detection and
configuring MAC address into WoL magic packet registers

Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Ling Pei Lee <pei.lee.ling@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove un-used "phy-reset-delay" property which found when do dtbs_check
(set additionalProperties: false in fsl,fec.yaml).
Double check current driver and commit history, "phy-reset-delay" never comes
up, so it should be safe to remove it.

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/net/fsl,fec.yaml
arch/arm/boot/dts/imx7d-mba7.dt.yaml: ethernet@30be0000: 'phy-reset-delay' does not match any of the regexes: 'pinctrl-[0-9]+'
arch/arm/boot/dts/imx7d-mba7.dt.yaml: ethernet@30bf0000: 'phy-reset-delay' does not match any of the regexes: 'pinctrl-[0-9]+'
/arch/arm/boot/dts/imx7s-mba7.dt.yaml: ethernet@30be0000: 'phy-reset-delay' does not match any of the regexes: 'pinctrl-[0-9]+'

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Correct node name for FEC which found when do dtbs_check.

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/net/fsl,fec.yaml
arch/arm/boot/dts/imx35-eukrea-mbimxsd35-baseboard.dt.yaml: fec@50038000: $nodename:0: 'fec@50038000' does not match '^ethernet(@.*)?$'
arch/arm/boot/dts/imx35-pdk.dt.yaml: fec@50038000: $nodename:0: 'fec@50038000' does not match '^ethernet(@.*)?$'

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In order to automate the verification of DT nodes convert fsl-fec.txt to
fsl,fec.yaml, and pass binding check with below command.

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/net/fsl,fec.yaml
  DTEX    Documentation/devicetree/bindings/net/fsl,fec.example.dts
  DTC     Documentation/devicetree/bindings/net/fsl,fec.example.dt.yaml
  CHECK   Documentation/devicetree/bindings/net/fsl,fec.example.dt.yaml

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently netdevsim only supports a single queue per port, which is
insufficient for testing multi-queue TC schedulers e.g. sch_mq.  Extend
the current sysfs interface so that users can create ports with multiple
queues:

$ echo "[ID] [PORT_COUNT] [NUM_QUEUES]" > /sys/bus/netdevsim/new_device

As an example, echoing "2 4 8" creates 4 ports, with 8 queues per port.
Note, this is compatible with the current interface, with default number
of queues set to 1.  For example, echoing "2 4" creates 4 ports with 1
queue per port; echoing "2" simply creates 1 port with 1 queue.

Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Open vSwitch kernel module uses the upcall mechanism to send
packets from kernel space to user space when it misses in the kernel
space flow table. The upcall sends packets via a Netlink socket.
Currently, a Netlink socket is created for every vport. In this way,
there is a 1:1 mapping between a vport and a Netlink socket.
When a packet is received by a vport, if it needs to be sent to
user space, it is sent via the corresponding Netlink socket.

This mechanism, with various iterations of the corresponding user
space code, has seen some limitations and issues:

* On systems with a large number of vports, there is a correspondingly
large number of Netlink sockets which can limit scaling.
(https://bugzilla.redhat.com/show_bug.cgi?id=1526306)
* Packet reordering on upcalls.
(https://bugzilla.redhat.com/show_bug.cgi?id=1844576)
* A thundering herd issue.
(https://bugzilla.redhat.com/show_bug.cgi?id=1834444)

This patch introduces an alternative, feature-negotiated, upcall
mode using a per-cpu dispatch rather than a per-vport dispatch.

In this mode, the Netlink socket to be used for the upcall is
selected based on the CPU of the thread that is executing the upcall.
In this way, it resolves the issues above as:

a) The number of Netlink sockets scales with the number of CPUs
rather than the number of vports.
b) Ordering per-flow is maintained as packets are distributed to
CPUs based on mechanisms such as RSS and flows are distributed
to a single user space thread.
c) Packets from a flow can only wake up one user space thread.

The corresponding user space code can be found at:
https://mail.openvswitch.org/pipermail/ovs-dev/2021-July/385139.html

Bugzilla: https://bugzilla.redhat.com/1844576
Signed-off-by: Mark Gray <mark.d.gray@redhat.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the clang build warning:

  drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:1862:13: error: variable 'cur_data_offset' set but not used [-Werror,-Wunused-but-set-variable]
        dma_addr_t cur_data_offset;

Signed-off-by: Bill Wendling <morbo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use 'bitmap_alloc()/bitmap_free()' instead of hand-writing it.
This makes the code less verbose.

Also, use 'bitmap_alloc()' instead of 'bitmap_zalloc()' because the bitmap
is fully overridden by a 'bitmap_copy()' call just after its allocation.

While at it, remove an extra and unneeded space.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It has been deal with the 'if (err' statement in rtnetlink_send()
and rtnl_unicast(). so remove unnecessary if statement.

v2: use the raw name rtnetlink_send().

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

The netlink_{broadcast, unicast} don't deal with 'if (err > 0' statement
but nlmsg_{multicast, unicast} do. The nlmsg_notify() contains them.
so use nlmsg_notify() instead. so that the caller wouldn't deal with
'if (err > 0' statement.

v2: use nlmsg_notify() will do well.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 'tail' pointer is also free-running count, so it needs to be masked
as 'adminq_prod_cnt' does, to become an index value of AdminQ buffer.

Fixes: 5cdad90 ("gve: Batch AQ commands for creating and destroying queues.")
Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-07-15

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

We've added 45 non-merge commits during the last 15 day(s) which contain
a total of 52 files changed, 3122 insertions(+), 384 deletions(-).

The main changes are:

1) Introduce bpf timers, from Alexei.

2) Add sockmap support for unix datagram socket, from Cong.

3) Fix potential memleak and UAF in the verifier, from He.

4) Add bpf_get_func_ip helper, from Jiri.

5) Improvements to generic XDP mode, from Kumar.

6) Support for passing xdp_md to XDP programs in bpf_prog_run, from Zvi.
===================

Signed-off-by: David S. Miller <davem@davemloft.net>

Cong Wang says:

====================

From: Cong Wang <cong.wang@bytedance.com>

This is the last patchset of the original large patchset. In the
previous patchset, a new BPF sockmap program BPF_SK_SKB_VERDICT
was introduced and UDP began to support it too. In this patchset,
we add BPF_SK_SKB_VERDICT support to Unix datagram socket, so that
we can finally splice Unix datagram socket and UDP socket. Please
check each patch description for more details.

To see the big picture, the previous patchsets are available here:
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=1e0ab70778bd86a90de438cc5e1535c115a7c396
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=89d69c5d0fbcabd8656459bc8b1a476d6f1efee4

and this patchset is available here:
https://github.com/congwang/linux/tree/sockmap3
Acked-by: John Fastabend <john.fastabend@gmail.com>
---
v5: lift socket state check for dgram
    remove ->unhash() case
    add retries for EAGAIN in all test cases
    remove an unused parameter of __unix_dgram_recvmsg()
    rebase on the latest bpf-next

v4: fix af_unix disconnect case
    add unix_unhash()
    split out two small patches
    reduce u->iolock critical section
    remove an unused parameter of __unix_dgram_recvmsg()

v3: fix Kconfig dependency
    make unix_read_sock() static
    fix a UAF in unix_release()
    add a missing header unix_bpf.c

v2: separate out from the original large patchset
    rebase to the latest bpf-next
    clean up unix_read_sock()
    export sock_map_close()
    factor out some helpers in selftests for code reuse
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Add two test cases to ensure redirection between udp and unix
work bidirectionally.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-12-xiyou.wangcong@gmail.com

Add a test case to ensure redirection between two AF_UNIX
datagram sockets work.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-11-xiyou.wangcong@gmail.com