Re: [lkp-robot] [blk] 47e0fb461f: BUG:unable_to_handle_kernel

[Tejun Heo]

Hello,

On Sat, Sep 30, 2017 at 01:21:13PM -0700, Linus Torvalds wrote:
> Tejun, any ideas? The original report is at
> 
>    https://lkml.org/lkml/2017/9/20/939
> 
> in case you don't see it in your inbox from lkml.

So, in the full log, there is an earlier warning.

 [   60.198729] ------------[ cut here ]------------
 [   60.199708] WARNING: CPU: 0 PID: 1 at drivers/ata/libata-core.c:6533 ata_host_detach+0x65/0xef
 [   60.201642] CPU: 0 PID: 1 Comm: swapper Tainted: G S              4.12.0-rc5-00126-g47e0fb46 #1
 [   60.203370] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
 [   60.205276] task: d9b10040 task.stack: d9b0a000
 [   60.206377] EIP: ata_host_detach+0x65/0xef
 [   60.207254] EFLAGS: 00210246 CPU: 0
 [   60.208051] EAX: fffffffd EBX: d5f80000 ECX: 00000000 EDX: d57d6a80
 [   60.209158] ESI: 00200282 EDI: 00000000 EBP: d9b0be70 ESP: d9b0be60
 [   60.210262]  DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068
 [   60.211264] CR0: 80050033 CR2: 00000000 CR3: 02a75000 CR4: 001406b0
 [   60.212370] Call Trace:
 [   60.213060]  ata_pci_remove_one+0xe/0x10
 [   60.213914]  piix_remove_one+0x25/0x28
 [   60.214750]  pci_device_remove+0x1c/0x44
 [   60.215607]  driver_probe_device+0x188/0x34d
 [   60.216501]  __driver_attach+0x64/0xb4
 [   60.217341]  bus_for_each_dev+0x4f/0x63
 [   60.218175]  driver_attach+0x14/0x16
 [   60.218988]  ? driver_probe_device+0x34d/0x34d
 [   60.219895]  bus_add_driver+0xba/0x1d4
 [   60.220721]  driver_register+0x6e/0xa0
 [   60.221562]  __pci_register_driver+0x28/0x2b
 [   60.222465]  ? pdc_sata_pci_driver_init+0x16/0x16
 [   60.223406]  piix_init+0x14/0x24
 [   60.224178]  do_one_initcall+0x89/0x12d
 [   60.225016]  ? parse_args+0x102/0x298
 [   60.225915] sd 1:0:0:0: [sda] 16384 512-byte logical blocks: (8.39 MB/8.00 MiB)
 [   60.227523]  kernel_init_freeable+0xec/0x168
 [   60.228421]  ? rest_init+0x6a/0x6a
 [   60.229225]  kernel_init+0x8/0xcb
 [   60.230003]  ret_from_fork+0x19/0x30

It looks like somebody is trying to detach the device while async
probing is in progress, making later async operations free-after-use.
There was a driver core driver detach autotest feature which
incorrectly invoked driver detach while async probes are in progress
and this looks like that.  This has already been fixed.  Xialong, can
you repro this on the latest kernel?

Thanks.

-- 
tejun