FYI, we noticed the following commit:

commit: 3361eef782f35ae681d265270067ee7effc37ea4 ("Add commands to create or update a superblock")
https://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git mount-context

in testcase: boot

on test machine: qemu-system-x86_64 -enable-kvm -m 420M

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


+------------------------------------------------------------------+------------+------------+
|                                                                  | f9d949ec8b | 3361eef782 |
+------------------------------------------------------------------+------------+------------+
| boot_successes                                                   | 6          | 0          |
| boot_failures                                                    | 2          | 16         |
| invoked_oom-killer:gfp_mask=0x                                   | 2          |            |
| Mem-Info                                                         | 2          |            |
| Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 2          |            |
| BUG:stack_guard_page_was_hit_at#(stack_is#..#)                   | 0          | 16         |
| Kernel_panic-not_syncing:Fatal_exception                         | 0          | 16         |
+------------------------------------------------------------------+------------+------------+



[    0.230249] BUG: stack guard page was hit at ffffc900000d4dae (stack is ffffc900000d0000..ffffc900000d3fff)
[    0.232043] kernel stack overflow (page fault): 0000 [#1] SMP
[    0.233048] Modules linked in:
[    0.233773] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc1-00021-g3361eef #10
[    0.236629] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[    0.238465] task: ffff88000ba38000 task.stack: ffffc900000d0000
[    0.239558] RIP: 0010:legacy_monolithic_mount_data+0x39/0xb0
[    0.240542] RSP: 0000:ffffc900000d3d50 EFLAGS: 00010282
[    0.241482] RAX: ffff88000bbea000 RBX: ffffc900000d3db6 RCX: 00000000000003cf
[    0.242630] RDX: 657a697365676170 RSI: 00000000000001b0 RDI: ffff88000bbea008
[    0.243814] RBP: ffffc900000d3d60 R08: ffff88000be1f300 R09: ffff88000b801b40
[    0.244994] R10: ffff88000bbea000 R11: ffffc900000d3dc3 R12: ffff88000bbe2900
[    0.246196] R13: ffffc900000d3db6 R14: ffffffff8242f5e0 R15: 0000000000000800
[    0.247389] FS:  0000000000000000(0000) GS:ffff88000be00000(0000) knlGS:0000000000000000
[    0.249056] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.250078] CR2: ffffc900000d4dae CR3: 0000000001e09000 CR4: 00000000000006f0
[    0.251217] Call Trace:
[    0.251912]  vfs_kern_mount+0x78/0xf0
[    0.252693]  kern_mount_data+0x19/0x30
[    0.253497]  init_hugetlbfs_fs+0xe3/0x15a
[    0.254313]  ? proc_create_data+0x76/0xb0
[    0.255132]  ? init_ramfs_fs+0x25/0x25
[    0.255975]  ? set_debug_rodata+0x17/0x17
[    0.256822]  do_one_initcall+0x43/0x170
[    0.257620]  ? set_debug_rodata+0x17/0x17
[    0.258438]  kernel_init_freeable+0x1a7/0x22f
[    0.259288]  ? rest_init+0x90/0x90
[    0.260076]  kernel_init+0xe/0x110
[    0.260835]  ret_from_fork+0x2c/0x40
[    0.261610] Code: 00 00 48 85 f6 74 7f 55 48 89 e5 41 54 53 48 8b 47 58 48 89 f3 49 89 fc 48 85 c0 74 42 48 8b 13 48 8d 78 08 48 83 e7 f8 48 89 10 <48> 8b 93 f8 0f 00 00 48 89 90 f8 0f 00 00 48 29 f8 48 29 c3 05 
[    0.264701] RIP: legacy_monolithic_mount_data+0x39/0xb0 RSP: ffffc900000d3d50
[    0.265858] ---[ end trace c9f5c67c1f791f62 ]---


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,
Kernel Test Robot