Re: [lkp-robot] [rcu] b332151a29: kernel_BUG_at_mm/slab.c

From: Jens Axboe
Date: Fri Jan 20 2017 - 11:09:43 EST


On 01/20/2017 08:01 AM, Sebastian Andrzej Siewior wrote:
> On 2017-01-19 09:02:16 [+0800], kernel test robot wrote:
>> test-description: Trinity is a linux system call fuzz tester.
>
> you don't even get to fire up trinity. With and without the patch you
> crash very early.
>
>> +-----------------------------------------------------+------------+------------+
>> | | d5f6ab9c11 | b332151a29 |
>> +-----------------------------------------------------+------------+------------+
>> | boot_successes | 0 | 0 |
>> | boot_failures | 6 | 8 |
>> | WARNING:at_include/linux/kref.h:#kobject_get | 6 | 8 |
>> | WARNING:at_arch/x86/mm/dump_pagetables.c:#note_page | 2 | 2 |
>> | kernel_BUG_at_mm/slab.c | 0 | 4 |
>> | invalid_opcode:#[##]PREEMPT_SMP | 0 | 4 |
>> | Kernel_panic-not_syncing:Fatal_exception | 0 | 6 |
>> | BUG:unable_to_handle_kernel | 0 | 2 |
>> | Oops | 0 | 2 |
>> +-----------------------------------------------------+------------+------------+
>
> There is no successful boot. The pattern changes with patch in question
> applied.
>
>> [ 8.044624] sd 0:0:0:0: [sda] Synchronizing SCSI cache
>> [ 8.055721] slab: double free detected in cache 'kmalloc-32', objp 8af558c0
>> [ 8.057138] ------------[ cut here ]------------
>> [ 8.058085] kernel BUG at mm/slab.c:2624!
>> [ 8.059255] invalid opcode: 0000 [#1] PREEMPT SMP

Is there a full trace of this?

> yes. With and without the patch there is a lot of wrong stuff like
> complains about a kobject initialized again. This leads to a double free
> at some point.

And what patch are we talking about? I don't mind being CC'ed into a thread,
but some context and background would be immensely helpful here...

--
Jens Axboe