Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: 3d5f2fa9faa040eb12bf93ddd8dac31b240609e7 ("[PATCH] x86/cpu: correct values for GDT_ENTRY_INIT")
url: https://github.com/0day-ci/linux/commits/Lukas-Bulwahn/x86-cpu-correct-values-for-GDT_ENTRY_INIT/20201126-195908
base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 9ea041b5e564b909207110a9edc04b287507756c

in testcase: boot

on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G

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


+-----------------------------------------------------------+------------+------------+
|                                                           | 9ea041b5e5 | 3d5f2fa9fa |
+-----------------------------------------------------------+------------+------------+
| boot_failures                                             | 0          | 4          |
| Kernel_panic-not_syncing:Attempted_to_kill_init!exitcode= | 0          | 4          |
+-----------------------------------------------------------+------------+------------+


If you fix the issue, kindly add following tag
Reported-by: kernel test robot <oliver.sang@intel.com>


[    2.499285]     nmi_watchdog=panic
[    2.500042]     prompt_ramdisk=0
[    2.500782]     vga=normal
[    2.501417]     watchdog_thresh=60
[    2.502444] traps: init[1] general protection fault ip:f7f66a14 sp:ffcb0370 error:0 in libc.so[f7f12000+67000]
[    2.504610] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[    2.506391] CPU: 1 PID: 1 Comm: init Not tainted 5.10.0-rc4-00713-g3d5f2fa9faa0 #1
[    2.508040] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[    2.509906] Call Trace:
[    2.510558]  dump_stack+0x57/0x6a
[    2.511277]  panic+0xfd/0x2be
[    2.511931]  do_exit.cold+0xa0/0xee
[    2.512685]  do_group_exit+0x35/0xa0
[    2.513481]  get_signal+0x16e/0x8b0
[    2.514336]  arch_do_signal_or_restart+0xe4/0x250
[    2.515340]  ? signal_wake_up_state+0x10/0x20
[    2.516345]  ? __send_signal+0x1de/0x3e0
[    2.517318]  ? force_sig_info_to_task+0xb5/0xd0
[    2.518407]  exit_to_user_mode_prepare+0xba/0x130
[    2.519453]  irqentry_exit_to_user_mode+0x5/0x20
[    2.520506]  exc_general_protection+0x22b/0x300
[    2.521520]  ? asm_exc_general_protection+0x8/0x30
[    2.522557]  asm_exc_general_protection+0x1e/0x30
[    2.523562] RIP: 0023:0xf7f66a14
[    2.524273] Code: Unable to access opcode bytes at RIP 0xf7f669ea.
[    2.525455] RSP: 002b:00000000ffcb0370 EFLAGS: 00000200
[    2.526568] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[    2.528052] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[    2.529611] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[    2.531195] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    2.532663] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    2.542399] Kernel Offset: 0x39a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Kboot worker: lkp-worker47


To reproduce:

        # build kernel
	cd linux
	cp config-5.10.0-rc4-00713-g3d5f2fa9faa0 .config
	make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage

        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,
Oliver Sang