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

commit: 19efe000d3258032d9a1dfb25313a092f9454da0 ("x86: Remap the IRQ stack so it has guard pages")
https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git x86/guard_pages

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):


+------------------------------------------------------------------+------------+------------+
|                                                                  | 0d997f71d5 | 19efe000d3 |
+------------------------------------------------------------------+------------+------------+
| boot_successes                                                   | 6          | 0          |
| boot_failures                                                    | 5          | 32         |
| invoked_oom-killer:gfp_mask=0x                                   | 5          |            |
| Mem-Info                                                         | 5          |            |
| Out_of_memory:Kill_process                                       | 3          |            |
| Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 3          |            |
| RIP:__put_user_4                                                 | 1          |            |
| PANIC:double_fault                                               | 0          | 32         |
| RIP:trace_hardirqs_off_thunk                                     | 0          | 32         |
| Kernel_panic-not_syncing:Machine_halted                          | 0          | 32         |
| WARNING:kernel_stack                                             | 0          | 32         |
+------------------------------------------------------------------+------------+------------+



[    0.004000]  memory used by lock dependency info: 7871 kB
[    0.004000]  per task-struct memory footprint: 2688 bytes
[    0.004000] ACPI: Core revision 20180531
[    0.004000] clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604467 ns
[    0.004000] hpet clockevent registered
[    0.004000] PANIC: double fault, error_code: 0x0
[    0.004000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.18.0-rc4-00074-g19efe000 #2
[    0.004000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[    0.004000] RIP: 0010:trace_hardirqs_off_thunk+0xb/0x1c
[    0.004000] Code: 5f 5d c3 55 48 89 e5 57 56 52 51 50 41 50 41 51 41 52 41 53 48 8b 7d 08 e8 f5 4e 2b 00 eb 34 55 48 89 e5 57 56 52 51 50 41 50 <41> 51 41 52 41 53 48 8b 7d 08 e8 eb 52 2b 00 eb 18 55 48 89 e5 57 
[    0.004000] RSP: 0000:ffffc90000000000 EFLAGS: 00010087
[    0.004000] RAX: 0000000082800a97 RBX: 0000000000000001 RCX: ffffffff82800a97
[    0.004000] RDX: 0000000000000000 RSI: ffffffff82800f68 RDI: ffffffff83678c68
[    0.004000] RBP: ffffc90000000030 R08: 0000000000000000 R09: 0000000000000000
[    0.004000] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    0.004000] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    0.004000] FS:  0000000000000000(0000) GS:ffff880013400000(0000) knlGS:0000000000000000
[    0.004000] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.004000] CR2: ffffc8fffffffff8 CR3: 000000000366e000 CR4: 00000000000406b0
[    0.004000] Call Trace:
[    0.004000] Kernel panic - not syncing: Machine halted.
[    0.004000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.18.0-rc4-00074-g19efe000 #2
[    0.004000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[    0.004000] Call Trace:
[    0.004000]  <#DF>
[    0.004000]  dump_stack+0x9b/0xe7
[    0.004000]  panic+0x1ad/0x325
[    0.004000]  ? refcount_error_report+0x267/0x267
[    0.004000]  df_debug+0x32/0x32
[    0.004000]  do_double_fault+0x1b3/0x1c7
[    0.004000]  double_fault+0x23/0x30
[    0.004000] RIP: 0010:trace_hardirqs_off_thunk+0xb/0x1c
[    0.004000] Code: 5f 5d c3 55 48 89 e5 57 56 52 51 50 41 50 41 51 41 52 41 53 48 8b 7d 08 e8 f5 4e 2b 00 eb 34 55 48 89 e5 57 56 52 51 50 41 50 <41> 51 41 52 41 53 48 8b 7d 08 e8 eb 52 2b 00 eb 18 55 48 89 e5 57 
[    0.004000] RSP: 0000:ffffc90000000000 EFLAGS: 00010087
[    0.004000] RAX: 0000000082800a97 RBX: 0000000000000001 RCX: ffffffff82800a97
[    0.004000] RDX: 0000000000000000 RSI: ffffffff82800f68 RDI: ffffffff83678c68
[    0.004000] RBP: ffffc90000000030 R08: 0000000000000000 R09: 0000000000000000
[    0.004000] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    0.004000] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    0.004000]  ? native_iret+0x7/0x7
[    0.004000]  ? async_page_fault+0x8/0x30
[    0.004000] WARNING: kernel stack regs at (____ptrval____) in swapper/0:0 has bad 'bp' value (____ptrval____)
[    0.004000] unwind stack type:0 next_sp:(____ptrval____) mask:0x20 graph_idx:0
[    0.004000] (____ptrval____): fffffe0000008e00 (0xfffffe0000008e00)
[    0.004000] (____ptrval____): ffffffff81045a52 (show_trace_log_lvl+0x1ec/0x2c8)
[    0.004000] (____ptrval____): ffffffff82800f68 (async_page_fault+0x8/0x30)
[    0.004000] (____ptrval____): fffffe0000008fd8 (0xfffffe0000008fd8)


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