FYI, we noticed the following commit (built with gcc-6):

commit: 10043e02db7f8a4161f76434931051e7d797a5f6 ("x86/cpu_entry_area: Add debugstore entries to cpu_entry_area")
https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git WIP.x86/pti

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 IvyBridge -m 420M

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


+------------------------------------------------+------------+------------+
|                                                | 4b6bbe95b8 | 10043e02db |
+------------------------------------------------+------------+------------+
| boot_successes                                 | 8          | 0          |
| boot_failures                                  | 0          | 8          |
| kernel_BUG_at_arch/x86/mm/physaddr.c           | 0          | 6          |
| PANIC:early_exception                          | 0          | 6          |
| RIP:__phys_addr                                | 0          | 6          |
| BUG:soft_lockup-CPU##stuck_for#s               | 0          | 2          |
| RIP:rb_erase                                   | 0          | 1          |
| Kernel_panic-not_syncing:softlockup:hung_tasks | 0          | 2          |
| RIP:rbtree_test_init                           | 0          | 1          |
+------------------------------------------------+------------+------------+



[    0.000000] kernel BUG at arch/x86/mm/physaddr.c:27!
PANIC: early exception 0x06 IP 10:ffffffff8115586f error 0 cr2 0xffff88000e468000
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.14.0-00160-g10043e02 #1
[    0.000000] task: ffffffff8a4683c0 task.stack: ffffffff8a400000
[    0.000000] RIP: 0010:__phys_addr+0x268/0x276
[    0.000000] RSP: 0000:ffffffff8a407bd8 EFLAGS: 00010002 ORIG_RAX: 0000000000000000
[    0.000000] RAX: 0000000000000000 RBX: 0000780000000000 RCX: 1ffffffff17a9a01
[    0.000000] RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffffffff8bd4d340
[    0.000000] RBP: ffffffff8a407bf8 R08: 0000000000000001 R09: ffffffff8a407a48
[    0.000000] R10: ffff880000010000 R11: ffff880000010fff R12: 0000000000000001
[    0.000000] R13: 0000000000000001 R14: 0000000000000000 R15: fffffbd00c401000
[    0.000000] FS:  0000000000000000(0000) GS:ffffffff8cb4d000(0000) knlGS:0000000000000000
[    0.000000] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.000000] CR2: ffff88000e468000 CR3: 000000000cde8000 CR4: 00000000000406b0
[    0.000000] Call Trace:
[    0.000000]  kasan_populate_shadow+0x3f2/0x497
[    0.000000]  ? 0xffffffff81000000
[    0.000000]  kasan_init+0x12e/0x2b2
[    0.000000]  setup_arch+0x2825/0x2a2c
[    0.000000]  ? reserve_standard_io_resources+0x36/0x36
[    0.000000]  ? vprintk_func+0x1ed/0x1f6
[    0.000000]  ? printk+0x94/0xb0
[    0.000000]  ? show_regs_print_info+0x60/0x60
[    0.000000]  start_kernel+0xc8/0x15f4
[    0.000000]  ? mem_encrypt_init+0xb/0xb
[    0.000000]  ? early_idt_handler_common+0x3b/0x52
[    0.000000]  x86_64_start_reservations+0x2a/0x2c
[    0.000000]  x86_64_start_kernel+0x72/0x75
[    0.000000]  secondary_startup_64+0xa5/0xb0
[    0.000000] Code: e0 07 38 c2 0f 9e c1 84 d2 0f 95 c0 84 c1 74 0a be 08 00 00 00 e8 0a f5 77 00 49 8d 75 02 48 ff 04 f5 28 d3 d4 8b 45 84 e4 74 02 <0f> 0b 48 89 d8 5b 41 5c 41 5d 41 5e 5d c3 e8 9e c1 0a 07 55 b8 

Elapsed time: 10

#!/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-tiny-i386-2016-04-22.cgz
	/lkp/lkp/lkp-i386.cgz
	/osimage/deps/debian-x86_64-2016-08-31.cgz/run-ipconfig.i386_2016-09-03.cgz
	/osimage/pkg/debian-x86_64-2016-08-31.cgz/trinity-static-i386-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-ivb41-yocto-ia32-30-0 256G

kvm=(
	qemu-system-x86_64
	-enable-kvm
	-cpu IvyBridge
	-kernel $kernel
	-initrd initrd.img
	-m 420
	-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-ivb41-yocto-ia32-30-0,media=disk,if=virtio
	-serial stdio
	-display none
	-monitor null
)

append=(
	ip=::::vm-ivb41-yocto-ia32-30::dhcp
	root=/dev/ram0
	user=lkp
	job=/job-script
	ARCH=x86_64
	kconfig=x86_64-randconfig-ne0-12241015
	branch=linux-devel/devel-catchup-201712241239
	commit=10043e02db7f8a4161f76434931051e7d797a5f6
	BOOT_IMAGE=/pkg/linux/x86_64-randconfig-ne0-12241015/gcc-6/10043e02db7f8a4161f76434931051e7d797a5f6/vmlinuz-4.14.0-00160-g10043e02
	max_uptime=1500
	RESULT_ROOT=/result/trinity/300s/vm-ivb41-yocto-ia32/yocto-tiny-i386-2016-04-22.cgz/x86_64-randconfig-ne0-12241015/gcc-6/10043e02db7f8a4161f76434931051e7d797a5f6/0
	result_service=tmpfs
	debug
	apic=debug
	sysrq_always_enabled
	rcupdate.rcu_cpu_stall_timeout=100
	net.ifnames=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,
Xiaolong