Re: [pgtable_trans_huge_withdraw] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020

From: Kirill A. Shutemov
Date: Mon Oct 30 2017 - 05:19:47 EST


On Mon, Oct 30, 2017 at 12:37:01AM +0100, Fengguang Wu wrote:
> CC MM people.
>
> On Sun, Oct 29, 2017 at 11:51:55PM +0100, Fengguang Wu wrote:
> > Hi Linus,
> >
> > Up to now we see the below boot error/warnings when testing v4.14-rc6.
> >
> > They hit the RC release mainly due to various imperfections in 0day's
> > auto bisection. So I manually list them here and CC the likely easy to
> > debug ones to the corresponding maintainers in the followup emails.
> >
> > boot_successes: 4700
> > boot_failures: 247
> >
> > BUG:kernel_hang_in_test_stage: 152
> > BUG:kernel_reboot-without-warning_in_test_stage: 10
> > BUG:sleeping_function_called_from_invalid_context_at_kernel/locking/mutex.c: 1
> > BUG:sleeping_function_called_from_invalid_context_at_kernel/locking/rwsem.c: 3
> > BUG:sleeping_function_called_from_invalid_context_at_mm/page_alloc.c: 21
> > BUG:soft_lockup-CPU##stuck_for#s: 1
> > BUG:unable_to_handle_kernel: 13
>
> Here is the call trace:
>
> [ 956.669197] [ 956.670421] stress-ng: fail: [27945] stress-ng-numa:
> get_mempolicy: errno=22 (Invalid argument)

Can you also share how you run stress-ng? Is it reproducible?

--
Kirill A. Shutemov