lkml.org 
[lkml]   [2018]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: Kernel 4.17.4 lockup
On Wed, Jul 11, 2018 at 8:13 AM, Dave Hansen <dave.hansen@intel.com> wrote:
> On 07/11/2018 07:56 AM, H.J. Lu wrote:
>> On Mon, Jul 9, 2018 at 8:47 PM, Dave Hansen <dave.hansen@intel.com> 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.

This is a quad-core machine with HT and 6 GB RAM. The workload is
x32 GCC build and test with "make -j8". The bug is triggered during GCC
test after a couple hours. I have a script to set up my workload:

https://github.com/hjl-tools/gcc-regression

with a cron job

# It takes about 3 hour to bootstrap x86-64 GCC and 3 hour to run tests,
TIMEOUT=480
# Run it every hour,
30 * * * * /export/gnu/import/git/gcc-test-x32/gcc-build -mx32
--with-pic > /dev/null 2>&1


--
H.J.
\
 
 \ /
  Last update: 2018-07-15 22:05    [W:0.111 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site