Re: Kernel 4.17.4 lockup

[Dave Hansen]

On 07/11/2018 07:56 AM, H.J. Lu wrote:
> On Mon, Jul 9, 2018 at 8:47 PM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>> On 07/09/2018 07:14 PM, H.J. Lu wrote:
>>>> I'd really want to see this reproduced without KASLR to make the oops
>>>> easier to read.  It would also be handy to try your workload with all
>>>> the pedantic debugging: KASAN, slab debugging, DEBUG_PAGE_ALLOC, etc...
>>>> and see if it still triggers.
>>> How can I turn them on at boot time?
>> The only thing you can add at boot time is slab debugging, and it's
>> probably the most useless of the three that I listed since you're not
>> actually seeing any slab corruption.
>>
>> The rest are compile-time options.
> I enabled KASAN, slab debugging, DEBUG_PAGE_ALLOC and disabled
> KASLR.  Machine locked up.  Here is the last kernel message before locking
> up.

KASAN looks to have caught it, although it scrolled off the screen.  I
can certainly imagine the oops you saw earlier being caused by stack
corruption.

Sounds like we need to reproduce this in an environment that can
actually capture a real oops.  Can you share more about your workload?
I'll see if I can get it to reproduce in a VM.