FYI, we noticed the following commit (built with gcc-5):

commit: f52001961d6e5c397e40c4d440103288cdce9a79 ("x86/vdso: Move out the CPU number store")
url: https://github.com/0day-ci/linux/commits/Chang-S-Bae/x86-Enable-FSGSBASE-instructions/20180602-125452


in testcase: boot

on test machine: qemu-system-i386 -enable-kvm -m 256M

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


+--------------------------------------------------------------------------------------+------------+------------+
|                                                                                      | 38a5d7ab4a | f52001961d |
+--------------------------------------------------------------------------------------+------------+------------+
| boot_successes                                                                       | 0          | 0          |
| boot_failures                                                                        | 14         | 36         |
| WARNING:at_lib/debugobjects.c:#__debug_object_init                                   | 14         |            |
| EIP:__debug_object_init                                                              | 14         |            |
| BUG:kernel_hang_in_early-boot_stage,last_printk:Probing_EDD(edd=off_to_disable)...ok | 0          | 36         |
+--------------------------------------------------------------------------------------+------------+------------+



early console in setup code
Probing EDD (edd=off to disable)... ok
BUG: kernel hang in early-boot stage, last printk: Probing EDD (edd=off to disable)... ok
Linux version 4.17.0-rc6-00163-gf520019 #1
Command line: ip=::::vm-lkp-nhm-dp1-yocto-i386-16::dhcp root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-lkp-nhm-dp1-yocto-i386-16/boot-1-yocto-tiny-i386-2016-04-22.cgz-f52001961d6e5c397e40c4d440103288cdce9a79-20180604-59345-q3lbrc-0.yaml ARCH=i386 kconfig=i386-randconfig-x0-06021157 branch=linux-devel/devel-catchup-201806021429 commit=f52001961d6e5c397e40c4d440103288cdce9a79 BOOT_IMAGE=/pkg/linux/i386-randconfig-x0-06021157/gcc-5/f52001961d6e5c397e40c4d440103288cdce9a79/vmlinuz-4.17.0-rc6-00163-gf520019 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-lkp-nhm-dp1-yocto-i386/yocto-tiny-i386-2016-04-22.cgz/i386-randconfig-x0-06021157/gcc-5/f52001961d6e5c397e40c4d440103288cdce9a79/0 LKP_SERVER=inn debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 net.ifnames=0 printk.devkmsg=on panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 drbd.minor_count=8 systemd.log_level=err ignore_loglevel console=tty0 earlyprintk=ttyS0,115200 console=ttyS0,115200 vga=normal rw drbd.minor_count=8 rcuperf.shutdown=0

Elapsed time: 310



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