Re: 047fb56f7e ("blk-mq: fix changelog"): BUG: unable to handle kernel NULL pointer dereference at 00000030
From: Greg Kroah-Hartman
Date: Sat Jan 05 2019 - 12:35:53 EST
On Sun, Jan 06, 2019 at 01:18:42AM +0800, kernel test robot wrote:
> Greetings,
>
> 0day kernel testing robot got the below dmesg and the first bad commit is
>
> https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git debugfs_cleanup
>
> commit 047fb56f7ecf53620d6e93fbcc8ca9166108d14c
> Author: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> AuthorDate: Fri Jan 4 14:06:22 2019 +0100
> Commit: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> CommitDate: Fri Jan 4 17:29:15 2019 +0100
>
> blk-mq: fix changelog
>
> 464573328e wireless: fix changelog
> 047fb56f7e blk-mq: fix changelog
> 24aeb03f70 lib: WIP, break up
> +------------------------------------------+------------+------------+------------+
> | | 464573328e | 047fb56f7e | 24aeb03f70 |
> +------------------------------------------+------------+------------+------------+
> | boot_successes | 33 | 0 | 0 |
> | boot_failures | 0 | 13 | 19 |
> | BUG:unable_to_handle_kernel | 0 | 13 | 19 |
> | Oops:#[##] | 0 | 13 | 19 |
> | EIP:debugfs_create_files | 0 | 13 | 19 |
> | Kernel_panic-not_syncing:Fatal_exception | 0 | 13 | 19 |
> +------------------------------------------+------------+------------+------------+
>
> [ 1.939685] toshiba: not a supported Toshiba laptop
> [ 1.940314] platform pc8736x_gpio.0: NatSemi pc8736x GPIO Driver Initializing
> [ 1.941204] platform pc8736x_gpio.0: no device found
> [ 1.941848] nsc_gpio initializing
> [ 1.942249] Hangcheck: starting hangcheck timer 0.9.1 (tick is 180 seconds, margin is 60 seconds).
> [ 1.943923] BUG: unable to handle kernel NULL pointer dereference at 00000030
> [ 1.944889] #PF error: [normal kernel read fault]
> [ 1.945527] *pdpt = 0000000000000000 *pde = f000ff53f000ff53
> [ 1.946287] Oops: 0000 [#1] SMP PTI
> [ 1.946760] CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 4.20.0-11088-g047fb56 #1
> [ 1.947149] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
> [ 1.947149] Workqueue: events_unbound async_run_entry_fn
> [ 1.947149] EIP: debugfs_create_files+0x9/0x50
> [ 1.947149] Code: 00 e8 db 11 52 00 8b 16 8b 4e 04 8d 83 c0 03 00 00 e8 4b 24 da ff 5b 5e 5d c3 8d b4 26 00 00 00 00 55 89 e5 56 53 89 c6 89 cb <8b> 40 30 89 90 14 02 00 00 8b 01 85 c0 74 26 90 8d b4 26 00 00 00
> [ 1.947149] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: da18f800
> [ 1.947149] ESI: 00000000 EDI: da18f800 EBP: c005de24 ESP: c005de1c
> [ 1.947149] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210246
> [ 1.947149] CR0: 80050033 CR2: 00000030 CR3: 01da4000 CR4: 003406f0
> [ 1.947149] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
> [ 1.947149] DR6: fffe0ff0 DR7: 00000400
> [ 1.947149] Call Trace:
> [ 1.947149] blk_mq_debugfs_register_sched_hctx+0x2f/0x40
> [ 1.947149] blk_mq_init_sched+0x156/0x1c0
> [ 1.947149] elevator_init_mq+0x4b/0x80
> [ 1.947149] blk_mq_init_allocated_queue+0x409/0x460
> [ 1.947149] blk_mq_init_queue+0x23/0x60
> [ 1.947149] blk_mq_init_sq_queue+0x77/0x90
> [ 1.947149] floppy_async_init+0xc0/0xd2c
> [ 1.947149] ? __lock_acquire+0x35/0x860
> [ 1.947149] async_run_entry_fn+0x2e/0xf0
> [ 1.947149] process_one_work+0x195/0x3c0
> [ 1.947149] ? process_one_work+0x176/0x3c0
> [ 1.947149] worker_thread+0x39/0x3d0
> [ 1.947149] kthread+0xda/0x110
> [ 1.947149] ? process_one_work+0x3c0/0x3c0
> [ 1.947149] ? kthread_park+0xa0/0xa0
> [ 1.947149] ret_from_fork+0x19/0x30
> [ 1.947149] Modules linked in:
> [ 1.947149] CR2: 0000000000000030
> [ 1.947149] ---[ end trace 34fc82d8056f573a ]---
> [ 1.947150] BUG: unable to handle kernel NULL pointer dereference at 00000030
This is my fault, due to some debugfs patches I'm working on, it's not a
block-specific issue at the moment.
sorry for the noise.
greg k-h