pte race

[  948.390363] set_pte_at: racy dirty state clearing: 0x006800003fab2bd3 -> 0x006800003fab2fd3
[  948.398623] ------------[ cut here ]------------
[  948.403449] WARNING: at ./arch/arm64/include/asm/pgtable.h:286
[  948.409306] Modules linked in:
[  948.412384]
[  948.413884] CPU: 1 PID: 1164 Comm: dd Not tainted 4.4.1-devel-16.04.2 #327
[  948.420787] Hardware name: Marvell Armada-7040
[  948.428388] task: ffffffc03916c200 ti: ffffffc037a38000 task.ti: ffffffc037a38000
[  948.435909] PC is at ptep_set_access_flags+0x9c/0x17c
[  948.440981] LR is at ptep_set_access_flags+0x9c/0x17c
[  948.446053] pc : [<ffffffc00017d8bc>] lr : [<ffffffc00017d8bc>] pstate: 60000145
[  948.453479] sp : ffffffc037a3bc80
[  948.456806] x29: ffffffc037a3bc80 x28: ffffffc037a26a50
[  948.462164] x27: 0000000000000517 x26: 0000000000000002
[  948.467521] x25: ffffffc000bad773 x24: 0000000000517000
[  948.472876] x23: ffffffc037a26a50 x22: ffffffc037dfc8b8
[  948.478232] x21: 0000000000000001 x20: 0000000000000041
[  948.483587] x19: 006800003fab2fd3 x18: 0000000000000001
[  948.488942] x17: 0000007fa467a8b0 x16: 0000000000517000
[  948.494299] x15: 0000007fa466ac90 x14: 307830203e2d2033
[  948.499654] x13: 6462326261663330 x12: 3030303836303078
[  948.505009] x11: 30203a676e697261 x10: 656c632065746174
[  948.510364] x9 : 0000000000000184 x8 : 79636172203a7461
[  948.515719] x7 : ffffffc000b3ea68 x6 : ffffffc000474628
[  948.521075] x5 : 0000000000000007 x4 : 0000000000000000
[  948.526431] x3 : 0000000000000000 x2 : ffffffc037a38000
[  948.531787] x1 : 0000000000000001 x0 : 000000000000004f
[  948.537141]
[  948.538638] ---[ end trace b6418e4c8c4bbba3 ]---
[  948.543273] Call trace:
[  948.545733] [<ffffffc00017d8bc>] ptep_set_access_flags+0x9c/0x17c
[  948.551854] [<ffffffc00016f124>] handle_mm_fault+0xa10/0x15e8
[  948.557626] [<ffffffc000094d10>] do_page_fault+0x190/0x2dc
[  948.563136] [<ffffffc0000822a8>] do_mem_abort+0x40/0xa0
[  948.568383] Exception stack(0xffffffc037a3be30 to 0xffffffc037a3bf50)
[  948.574852] be20:                                   0000000000000000 0000000000200000
[  948.582715] be40: ffffffffffffffff 0000000000406f84 ffffffc037d33a00 ffffffc037d33a00