FYI, we noticed the following commit:

commit: 69218e47994da614e7af600bf06887750ab6657a ("x86: Remap GDT tables in the fixmap section")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master

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-i386 -enable-kvm -smp 2 -m 320M

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


+--------------------------------------------------------------+------------+------------+
|                                                              | f06bdd4001 | 69218e4799 |
+--------------------------------------------------------------+------------+------------+
| boot_successes                                               | 3          | 0          |
| boot_failures                                                | 5          | 8          |
| BUG:kernel_reboot-without-warning_in_boot_stage              | 4          |            |
| WARNING:at_arch/x86/include/asm/fpu/internal.h:#fpu__restore | 1          |            |
| BUG:kernel_hang_in_boot_stage                                | 0          | 8          |
+--------------------------------------------------------------+------------+------------+

[    0.000000] sysrq: sysrq always enabled.
[    0.000000] PID hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000000] Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Initializing CPU#0
[    0.000000] allocated 331644 bytes of page_ext
[    0.000000] Initializing HighMem for node 0 (00000000:00000000)
[    0.000000] Memory: 267332K/327160K available (14061K kernel code, 1104K rwdata, 4696K rodata, 2460K init, 13208K bss, 59828K reserved, 0K cma-reserved, 0K highmem)
[    0.000000] virtual kernel memory layout:
[    0.000000]     fixmap  : 0xffa74000 - 0xfffff000   (5676 kB)
[    0.000000]     pkmap   : 0xff400000 - 0xff800000   (4096 kB)
[    0.000000]     vmalloc : 0x547e0000 - 0xff3fe000   (2732 MB)
[    0.000000]     lowmem  : 0x40000000 - 0x53fe0000   ( 319 MB)
[    0.000000]       .init : 0x4236a000 - 0x425d1000   (2460 kB)
[    0.000000]       .data : 0x41dbb72c - 0x42368300   (5810 kB)
[    0.000000]       .text : 0x41000000 - 0x41dbb72c   (14061 kB)


Elapsed time: 480
BUG: kernel hang in boot stage

initrds=(
	/osimage/yocto/yocto-tiny-i386-2016-04-22.cgz
	/lkp/scheduled/vm-lkp-hsw01-yocto-i386-25/trinity-300s-yocto-tiny-i386-2016-04-22.cgz-69218e47994da614e7af600bf06887750ab6657a-20170319-117821-bls48g-0.cgz
	/lkp/lkp/lkp-i386.cgz


To reproduce:

        git clone https://github.com/01org/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Xiaolong