Re: [lkp] [sched] 817b8ebf33: WARNING: CPU: 0 PID: 2307 at kernel/fork.c:304 free_task+0x2f/0x4c

[Andy Lutomirski]

On Fri, Jul 8, 2016 at 8:04 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> On Thu, Jul 7, 2016 at 6:17 PM, kernel test robot <xiaolong.ye@xxxxxxxxx> wrote:
>>
>>
>> FYI, we noticed the following commit:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/vmap_stack
>> commit 817b8ebf33c489948ee5db93ab7ed483619a53a5 ("sched: Free the stack early if CONFIG_THREAD_INFO_IN_TASK")
>>
>> in testcase: boot
>>
>> on test machine: 1 threads qemu-system-i386 -enable-kvm with 192M memory
>>
>> caused below changes:
>
> I think I've tracked this down to a harmless bug in dup_task_struct
> error handling.  Fixed now.

Correction, copy_process.  I was able to reproduce this, so I'm
reasonable sure I'm right.

-- 
Andy Lutomirski
AMA Capital Management, LLC