net-next boot error

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: dc66fe43b7eb rds: send: Fix dead code in rds_sendmsg
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=127874c8400000
kernel config: https://syzkaller.appspot.com/x/.config?x=f34ce142a9f5f0e8
dashboard link: https://syzkaller.appspot.com/bug?extid=604f8271211546f5b3c7
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+604f82...@syzkaller.appspotmail.com

possible deadlock in static_key_slow_incsd 0:0:1:0: [sda] Attached SCSI disk
MACsec IEEE 802.1AE
tun: Universal TUN/TAP device driver, 1.6

============================================
WARNING: possible recursive locking detected
4.18.0-rc6+ #141 Not tainted
--------------------------------------------
swapper/0/1 is trying to acquire lock:
(____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at:
static_key_slow_inc+0x12/0x30 kernel/jump_label.c:124

but task is already holding lock:
(____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: get_online_cpus
include/linux/cpu.h:126 [inline]
(____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: init_vqs+0xe1a/0x1520
drivers/net/virtio_net.c:2777

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(cpu_hotplug_lock.rw_sem);
lock(cpu_hotplug_lock.rw_sem);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by swapper/0/1:
#0: (____ptrval____) (&dev->mutex){....}, at: device_lock
include/linux/device.h:1134 [inline]
#0: (____ptrval____) (&dev->mutex){....}, at: __driver_attach+0x15f/0x2f0
drivers/base/dd.c:820
#1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: get_online_cpus
include/linux/cpu.h:126 [inline]
#1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at:
init_vqs+0xe1a/0x1520 drivers/net/virtio_net.c:2777
#2: (____ptrval____) (xps_map_mutex){+.+.}, at:
__netif_set_xps_queue+0x243/0x23f0 net/core/dev.c:2278

stack backtrace:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.18.0-rc6+ #141
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
print_deadlock_bug kernel/locking/lockdep.c:1765 [inline]
check_deadlock kernel/locking/lockdep.c:1809 [inline]
validate_chain kernel/locking/lockdep.c:2405 [inline]
__lock_acquire.cold.65+0x1fb/0x486 kernel/locking/lockdep.c:3435
lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
cpus_read_lock+0x43/0xa0 kernel/cpu.c:289
static_key_slow_inc+0x12/0x30 kernel/jump_label.c:124
__netif_set_xps_queue+0xaac/0x23f0 net/core/dev.c:2320
netif_set_xps_queue+0x26/0x30 net/core/dev.c:2455
virtnet_set_affinity+0x2ba/0x4b0 drivers/net/virtio_net.c:1944
init_vqs+0xe22/0x1520 drivers/net/virtio_net.c:2778
virtnet_probe+0x1092/0x2260 drivers/net/virtio_net.c:3016
virtio_dev_probe+0x592/0x942 drivers/virtio/virtio.c:245
really_probe drivers/base/dd.c:446 [inline]
driver_probe_device+0x6ad/0x970 drivers/base/dd.c:588
__driver_attach+0x28b/0x2f0 drivers/base/dd.c:822
bus_for_each_dev+0x15d/0x1f0 drivers/base/bus.c:311
driver_attach+0x3d/0x50 drivers/base/dd.c:841
bus_add_driver+0x4b2/0x600 drivers/base/bus.c:667
driver_register+0x1c8/0x320 drivers/base/driver.c:170
register_virtio_driver+0x79/0xd0 drivers/virtio/virtio.c:296
virtio_net_driver_init+0x8d/0xc9 drivers/net/virtio_net.c:3209
do_one_initcall+0x127/0x913 init/main.c:884
do_initcall_level init/main.c:952 [inline]
do_initcalls init/main.c:960 [inline]
do_basic_setup init/main.c:978 [inline]
kernel_init_freeable+0x49b/0x58e init/main.c:1135
kernel_init+0x11/0x1b3 init/main.c:1061
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
vcan: Virtual CAN interface driver
vxcan: Virtual CAN Tunnel driver
slcan: serial line CAN interface driver
slcan: 10 dynamic interface channels.
CAN device driver interface
enic: Cisco VIC Ethernet NIC Driver, ver 2.3.0.53
e100: Intel(R) PRO/100 Network Driver, 3.5.24-k2-NAPI
e100: Copyright(c) 1999-2006 Intel Corporation
e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI
e1000: Copyright (c) 1999-2006 Intel Corporation.
e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k
e1000e: Copyright(c) 1999 - 2015 Intel Corporation.
sky2: driver version 1.30
PPP generic driver version 2.4.2
PPP BSD Compression module registered
PPP Deflate Compression module registered
PPP MPPE Compression module registered
NET: Registered protocol family 24
PPTP driver version 0.8.5
mac80211_hwsim: initializing netlink
ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
ieee80211 phy1: Selected rate control algorithm 'minstrel_ht'
usbcore: registered new interface driver asix
usbcore: registered new interface driver ax88179_178a
usbcore: registered new interface driver cdc_ether
usbcore: registered new interface driver net1080
usbcore: registered new interface driver cdc_subset
usbcore: registered new interface driver zaurus
usbcore: registered new interface driver cdc_ncm
aoe: AoE v85 initialised.
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-pci: EHCI PCI platform driver
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci-pci: OHCI PCI platform driver
uhci_hcd: USB Universal Host Controller Interface driver
usbcore: registered new interface driver usblp
usbcore: registered new interface driver usb-storage
i8042: PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,0x64 irq 1,12
i8042: Warning: Keylock active
serio: i8042 KBD port at 0x60,0x64 irq 1
serio: i8042 AUX port at 0x60,0x64 irq 12
mousedev: PS/2 mouse device common for all mice
rtc_cmos 00:00: RTC can wake from S4
rtc_cmos 00:00: registered as rtc0
rtc_cmos 00:00: alarms up to one day, 114 bytes nvram
i2c /dev entries driver
piix4_smbus 0000:00:01.3: SMBus base address uninitialized - upgrade BIOS
or use force_addr=0xaddr
i2c-parport-light: adapter type unspecified
usbcore: registered new interface driver RobotFuzz Open Source InterFace,
OSIF
usbcore: registered new interface driver i2c-tiny-usb
device-mapper: ioctl: 4.39.0-ioctl (2018-04-03) initialised:
dm-d...@redhat.com
device-mapper: raid: Loading target version 1.13.2
usbcore: registered new interface driver btusb
usnic_verbs: Cisco VIC (USNIC) Verbs Driver v1.0.3 (December 19, 2013)
usnic_verbs:usnic_uiom_init:585:
IOMMU required but not present or enabled. USNIC QPs will not function w/o
enabling IOMMU
usnic_verbs:usnic_ib_init:649:
Unable to initalize umem with err -1
iscsi: registered transport (iser)
OPA Virtual Network Driver - v1.0
hidraw: raw HID events driver (C) Jiri Kosina
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
NET: Registered protocol family 40
ashmem: initialized
NET: Registered protocol family 26
Mirror/redirect action on
Simple TC action Loaded
netem: version 1.3
u32 classifier
Actions configured
nf_conntrack_irc: failed to register helpers
nf_conntrack_sane: failed to register helpers
nf_conntrack_sip: failed to register helpers
xt_time: kernel timezone is -0000
IPVS: Registered protocols (TCP, UDP, SCTP, AH, ESP)
IPVS: Connection hash table configured (size=4096, memory=64Kbytes)
IPVS: ipvs loaded.
IPVS: [rr] scheduler registered.
IPVS: [wrr] scheduler registered.
IPVS: [lc] scheduler registered.
IPVS: [wlc] scheduler registered.
IPVS: [fo] scheduler registered.
IPVS: [ovf] scheduler registered.
IPVS: [lblc] scheduler registered.
IPVS: [lblcr] scheduler registered.
IPVS: [dh] scheduler registered.
IPVS: [sh] scheduler registered.
IPVS: [mh] scheduler registered.
IPVS: [sed] scheduler registered.
IPVS: [nq] scheduler registered.
IPVS: ftp: loaded support on port[0] = 21
IPVS: [sip] pe registered.
ipip: IPv4 and MPLS over IPv4 tunneling driver
gre: GRE over IPv4 demultiplexor driver
ip_gre: GRE over IPv4 tunneling driver
IPv4 over IPsec tunneling driver
ipt_CLUSTERIP: ClusterIP Version 0.8 loaded successfully
Initializing XFRM netlink socket
NET: Registered protocol family 10
Segment Routing with IPv6
mip6: Mobile IPv6
sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
ip6_gre: GRE over IPv6 tunneling driver
bpfilter: Loaded bpfilter_umh pid 2080
NET: Registered protocol family 15
Bridge firewalling registered
can: controller area network core (rev 20170425 abi 9)
NET: Registered protocol family 29
can: raw protocol (rev 20170425)
can: broadcast manager protocol (rev 20170425 t)
can: netlink gateway (rev 20170425) max_hops=1
Bluetooth: RFCOMM TTY layer initialized
Bluetooth: RFCOMM socket layer initialized
Bluetooth: RFCOMM ver 1.11
Bluetooth: BNEP (Ethernet Emulation) ver 1.3
Bluetooth: BNEP filters: protocol multicast
Bluetooth: BNEP socket layer initialized
Bluetooth: HIDP (Human Interface Emulation) ver 1.2
Bluetooth: HIDP socket layer initialized
RPC: Registered rdma transport module.
RPC: Registered rdma backchannel transport module.
NET: Registered protocol family 41
lec:lane_module_init: lec.c: initialized
mpoa:atm_mpoa_init: mpc.c: initialized
l2tp_core: L2TP core driver, V2.0
l2tp_ppp: PPPoL2TP kernel driver, V2.0
8021q: 802.1Q VLAN Support v1.8
input: AT Translated Set 2 keyboard as
/devices/platform/i8042/serio0/input/input2
DCCP: Activated CCID 2 (TCP-like)
DCCP: Activated CCID 3 (TCP-Friendly Rate Control)
sctp: Hash tables configured (bind 64/64)
tipc: Activated (version 2.0.0)
NET: Registered protocol family 30
tipc: Started in single node mode
NET: Registered protocol family 43
9pnet: Installing 9P2000 support
NET: Registered protocol family 36
Key type dns_resolver registered
Key type ceph registered
libceph: loaded (mon/osd proto 15/24)
openvswitch: Open vSwitch switching datapath
mpls_gso: MPLS GSO support
start plist test
end plist test
AVX2 version of gcm_enc/dec engaged.
AES CTR mode by8 optimization enabled
sched_clock: Marking stable (4559438359, 0)->(6126385605, -1566947246)
registered taskstats version 1
Loading compiled-in X.509 certificates
zswap: default zpool zbud not available
zswap: pool creation failed
Btrfs loaded, crc32c=crc32c-intel
Key type big_key registered
Key type encrypted registered
Magic number: 10:317:168
console [netcon0] enabled
netconsole: network logging started
gtp: GTP module loaded (pdp ctx size 104 bytes)
rdma_rxe: loaded
cfg80211: Loading compiled-in X.509 certificates for regulatory database
cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
platform regulatory.0: Direct firmware load for regulatory.db failed with
error -2
cfg80211: failed to load regulatory.db
ALSA device list:
#0: Dummy 1
#1: Loopback 1
#2: Virtual MIDI Card 1
input: ImExPS/2 Generic Explorer Mouse as
/devices/platform/i8042/serio1/input/input4
md: Waiting for all devices to be available before autodetect
md: If you don't use raid, use raid=noautodetect
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
devtmpfs: mounted
Freeing unused kernel memory: 3900K
Kernel memory protection disabled.
SELinux: Disabled at runtime.
SELinux: Unregistering netfilter hooks
audit: type=1404 audit(1532588961.277:2): enforcing=0 old_enforcing=0
auid=4294967295 ses=4294967295 enabled=0 old-enabled=1 lsm=selinux res=1
stty (2166) used greatest stack depth: 19664 bytes left
EXT4-fs (sda1): re-mounted. Opts: (null)
logsave (3615) used greatest stack depth: 17632 bytes left
random: dd: uninitialized urandom read (512 bytes read)
==================================================================
BUG: KASAN: slab-out-of-bounds in virtnet_receive
drivers/net/virtio_net.c:1356 [inline]
BUG: KASAN: slab-out-of-bounds in virtnet_poll+0x111a/0x1226
drivers/net/virtio_net.c:1421
Read of size 8 at addr ffff8801cee08ff0 by task ip/3969

CPU: 0 PID: 3969 Comm: ip Not tainted 4.18.0-rc6+ #141
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
virtnet_receive drivers/net/virtio_net.c:1356 [inline]
virtnet_poll+0x111a/0x1226 drivers/net/virtio_net.c:1421
napi_poll net/core/dev.c:6214 [inline]
net_rx_action+0x7a5/0x1920 net/core/dev.c:6280
__do_softirq+0x2e8/0xb17 kernel/softirq.c:292
do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1046
</IRQ>
do_softirq.part.18+0x155/0x1a0 kernel/softirq.c:336
do_softirq arch/x86/include/asm/preempt.h:23 [inline]
__local_bh_enable_ip+0x1ec/0x230 kernel/softirq.c:189
local_bh_enable include/linux/bottom_half.h:32 [inline]
virtnet_napi_enable+0x8c/0xb0 drivers/net/virtio_net.c:1264
virtnet_open+0x16d/0x4d0 drivers/net/virtio_net.c:1464
__dev_open+0x26d/0x410 net/core/dev.c:1392
__dev_change_flags+0x739/0x9c0 net/core/dev.c:7434
dev_change_flags+0x89/0x150 net/core/dev.c:7503
do_setlink+0xb16/0x3dd0 net/core/rtnetlink.c:2416
rtnl_newlink+0x138d/0x1d60 net/core/rtnetlink.c:3029
rtnetlink_rcv_msg+0x46e/0xc30 net/core/rtnetlink.c:4705
netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2447
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4723
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1336
netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:641 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:651
___sys_sendmsg+0x7fd/0x930 net/socket.c:2125
__sys_sendmsg+0x11d/0x290 net/socket.c:2163
__do_sys_sendmsg net/socket.c:2172 [inline]
__se_sys_sendmsg net/socket.c:2170 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2170
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f318d594320
Code: 02 48 83 c8 ff eb 8d 48 8b 05 14 7b 2a 00 f7 da 64 89 10 48 83 c8 ff
eb c9 90 83 3d d5 d2 2a 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 31 c3 48 83 ec 08 e8 5e ba 00 00 48 89 04 24
RSP: 002b:00007ffd985d8f38 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffd985dd030 RCX: 00007f318d594320
RDX: 0000000000000000 RSI: 00007ffd985d8f70 RDI: 0000000000000003
RBP: 00007ffd985d8f70 R08: 0000000000000000 R09: 000000000000000f
R10: 0000000000000000 R11: 0000000000000246 R12: 000000005b5973aa
R13: 0000000000000000 R14: 00000000006395c0 R15: 00007ffd985dd808

Allocated by task 1:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
__do_kmalloc mm/slab.c:3718 [inline]
__kmalloc+0x14e/0x760 mm/slab.c:3727
kmalloc_array include/linux/slab.h:635 [inline]
kcalloc include/linux/slab.h:646 [inline]
virtnet_alloc_queues drivers/net/virtio_net.c:2731 [inline]
init_vqs+0x127/0x1520 drivers/net/virtio_net.c:2769
virtnet_probe+0x1092/0x2260 drivers/net/virtio_net.c:3016
virtio_dev_probe+0x592/0x942 drivers/virtio/virtio.c:245
really_probe drivers/base/dd.c:446 [inline]
driver_probe_device+0x6ad/0x970 drivers/base/dd.c:588
__driver_attach+0x28b/0x2f0 drivers/base/dd.c:822
bus_for_each_dev+0x15d/0x1f0 drivers/base/bus.c:311
driver_attach+0x3d/0x50 drivers/base/dd.c:841
bus_add_driver+0x4b2/0x600 drivers/base/bus.c:667
driver_register+0x1c8/0x320 drivers/base/driver.c:170
register_virtio_driver+0x79/0xd0 drivers/virtio/virtio.c:296
virtio_net_driver_init+0x8d/0xc9 drivers/net/virtio_net.c:3209
do_one_initcall+0x127/0x913 init/main.c:884
do_initcall_level init/main.c:952 [inline]
do_initcalls init/main.c:960 [inline]
do_basic_setup init/main.c:978 [inline]
kernel_init_freeable+0x49b/0x58e init/main.c:1135
kernel_init+0x11/0x1b3 init/main.c:1061
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801cee08500
which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2800 bytes inside of
4096-byte region [ffff8801cee08500, ffff8801cee09500)
The buggy address belongs to the page:
page:ffffea00073b8200 count:1 mapcount:0 mapping:ffff8801dac00dc0 index:0x0
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea00073b7d88 ffffea00073b8288 ffff8801dac00dc0
raw: 0000000000000000 ffff8801cee08500 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8801cee08e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8801cee08f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8801cee08f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8801cee09000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8801cee09080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

[Dmitry Vyukov]

On Thu, Jul 26, 2018 at 11:29 AM, syzbot
<syzbot+604f82...@syzkaller.appspotmail.com> wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: dc66fe43b7eb rds: send: Fix dead code in rds_sendmsg
> git tree: net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=127874c8400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f34ce142a9f5f0e8
> dashboard link: https://syzkaller.appspot.com/bug?extid=604f8271211546f5b3c7
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+604f82...@syzkaller.appspotmail.com
>
> possible deadlock in static_key_slow_incsd 0:0:1:0: [sda] Attached SCSI disk
> MACsec IEEE 802.1AE
> tun: Universal TUN/TAP device driver, 1.6
>
> ============================================
> WARNING: possible recursive locking detected

+Tetsuo, perhaps this boot lockdep problem then disables lockdep for
actual testing. I think lockdep should respect panic_on_warn.

+virtio maintainers for this one
Probably something very recent.

> --
> You received this message because you are subscribed to the Google Groups
> "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to syzkaller-bug...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/syzkaller-bugs/000000000000352dc20571e3a0d8%40google.com.
> For more options, visit https://groups.google.com/d/optout.

[Steven Rostedt]

[ Added Thomas Gleixner ]

Here init_vqs() does:

get_online_cpus();
virtnet_set_affinity(vi);
put_online_cpus();

Which disables cpu hotplug and calls virtnet_set_affinity()

Note, get_online_cpus() is no longer recursive.

__netif_set_xps_queue() calls static_key_slow_inc() which will also do
a get_online_cpus() which will trigger this bug.

There's a static_key_slow_inc_cpuslocked() version that should be used
when get_online_cpus() is already taken, but I see
__netif_set_xps_queue() is called from several places, and I doubt it
is always called with get_online_cpus() held. Thus just using the
cpuslocked() version is probably not sufficient of a fix.

I don't know the code enough to offer other suggestions.

-- Steve

[Michael S. Tsirkin]

OK so the guess is it's due to combination of

commit 04157469b7b848f4a9978b63b1ea2ce62ad3a0a3
Author: Amritha Nambiar <amritha...@intel.com>
Date: Fri Jun 29 21:26:46 2018 -0700

net: Use static_key for XPS maps

which uses static_key_slow_inc and

commit 8af2c06ff4b144064b51b7f688194474123d9c9c
Author: Amritha Nambiar <amritha...@intel.com>
Date: Fri Jun 29 21:27:07 2018 -0700

net-sysfs: Add interface for Rx queue(s) map per Tx queue


which makes it all user-triggerable.