FYI, we noticed the following commit (built with gcc-7):

commit: b1f0502d04537ef55b0c296823affe332b100eb5 ("mm: VMA sequence count")
url: https://github.com/0day-ci/linux/commits/Laurent-Dufour/Speculative-page-faults/20180316-151833


in testcase: trinity
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -m 512M

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+----------------------------------------+------------+------------+
|                                        | 6a4ce82339 | b1f0502d04 |
+----------------------------------------+------------+------------+
| boot_successes                         | 8          | 4          |
| boot_failures                          | 0          | 4          |
| INFO:trying_to_register_non-static_key | 0          | 4          |
+----------------------------------------+------------+------------+



[   22.212940] INFO: trying to register non-static key.
[   22.213687] the code is fine but needs lockdep annotation.
[   22.214459] turning off the locking correctness validator.
[   22.227459] CPU: 0 PID: 547 Comm: trinity-main Not tainted 4.16.0-rc4-next-20180309-00007-gb1f0502 #239
[   22.228904] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[   22.230043] Call Trace:
[   22.230409]  dump_stack+0x5d/0x79
[   22.231025]  register_lock_class+0x226/0x45e
[   22.231827]  ? kvm_clock_read+0x21/0x30
[   22.232544]  ? kvm_sched_clock_read+0x5/0xd
[   22.233330]  __lock_acquire+0xa2/0x774
[   22.234152]  lock_acquire+0x4b/0x66
[   22.234805]  ? unmap_vmas+0x30/0x3d
[   22.245680]  unmap_page_range+0x56/0x48c
[   22.248127]  ? unmap_vmas+0x30/0x3d
[   22.248741]  ? lru_deactivate_file_fn+0x2c6/0x2c6
[   22.249537]  ? pagevec_lru_move_fn+0x9a/0xa9
[   22.250244]  unmap_vmas+0x30/0x3d
[   22.250791]  unmap_region+0xad/0x105
[   22.251419]  mmap_region+0x3cc/0x455
[   22.252011]  do_mmap+0x394/0x3e9
[   22.261224]  vm_mmap_pgoff+0x9c/0xe5
[   22.261798]  SyS_mmap_pgoff+0x19a/0x1d4
[   22.262475]  ? task_work_run+0x5e/0x9c
[   22.263163]  do_syscall_64+0x6d/0x103
[   22.263814]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[   22.264697] RIP: 0033:0x4573da
[   22.267248] RSP: 002b:00007fffa22f1398 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[   22.274720] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000004573da
[   22.276083] RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000
[   22.277343] RBP: 000000000000001c R08: 000000000000001c R09: 0000000000000000
[   22.278686] R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
[   22.279930] R13: 0000000000001000 R14: 0000000000000002 R15: 0000000000000000
[   22.391866] trinity-main uses obsolete (PF_INET,SOCK_PACKET)
[  327.566956] sysrq: SysRq : Emergency Sync
[  327.567849] Emergency Sync complete
[  327.569975] sysrq: SysRq : Resetting

Elapsed time: 330

#!/bin/bash

# To reproduce,
# 1) save job-script and this script (both are attached in 0day report email)
# 2) run this script with your compiled kernel and optional env $INSTALL_MOD_PATH

kernel=$1

initrds=(
	/osimage/yocto/yocto-minimal-x86_64-2016-04-22.cgz
	/lkp/lkp/lkp-x86_64.cgz
	/osimage/pkg/debian-x86_64-2016-08-31.cgz/trinity-static-x86_64-x86_64-6ddabfd2_2017-11-10.cgz
)

HTTP_PREFIX=https://github.com/0day-ci/lkp-qemu/raw/master
wget --timestamping "${initrds[@]/#/$HTTP_PREFIX}"

{
	cat "${initrds[@]//*\//}"
	[[ $INSTALL_MOD_PATH ]] && (
		cd "$INSTALL_MOD_PATH"
		find lib | cpio -o -H newc --quiet | gzip
	)
	echo  job-script | cpio -o -H newc --quiet | gzip
} > initrd.img

qemu-img create -f qcow2 disk-vm-kbuild-yocto-x86_64-62-0 256G

kvm=(
	qemu-system-x86_64
	-enable-kvm
	-cpu SandyBridge
	-kernel $kernel
	-initrd initrd.img
	-m 512
	-smp 1
	-device e1000,netdev=net0
	-netdev user,id=net0
	-boot order=nc
	-no-reboot
	-watchdog i6300esb
	-watchdog-action debug
	-rtc base=localtime
	-drive file=disk-vm-kbuild-yocto-x86_64-62-0,media=disk,if=virtio
	-serial stdio
	-display none
	-monitor null
)

append=(
	ip=::::vm-kbuild-yocto-x86_64-62::dhcp
	root=/dev/ram0
	user=lkp
	job=/job-script
	ARCH=x86_64
	kconfig=x86_64-acpi-redef
	branch=linux-devel/devel-catchup-201803161558
	commit=b1f0502d04537ef55b0c296823affe332b100eb5
	BOOT_IMAGE=/pkg/linux/x86_64-acpi-redef/gcc-7/b1f0502d04537ef55b0c296823affe332b100eb5/vmlinuz-4.16.0-rc4-next-20180309-00007-gb1f0502
	max_uptime=1500
	RESULT_ROOT=/result/trinity/300s/vm-kbuild-yocto-x86_64/yocto-minimal-x86_64-2016-04-22.cgz/x86_64-acpi-redef/gcc-7/b1f0502d04537ef55b0c296823affe332b100eb5/0


To reproduce:

        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
lkp