Re: [serial] 679193b7ba: BUG:spinlock_bad_magic_on_CPU

[Greg Kroah-Hartman]

On Sun, Aug 02, 2020 at 01:50:29PM +0300, Andy Shevchenko wrote:
> On Sun, Aug 2, 2020 at 8:54 AM kernel test robot <lkp@xxxxxxxxx> wrote:
> >
> > Greeting,
> >
> > FYI, we noticed the following commit (built with gcc-9):
> >
> > commit: 679193b7baf8d88e41cbeb397ca17f797654947d ("serial: 8250: Let serial core initialise spin lock")
> > https://git.kernel.org/cgit/linux/kernel/git/gregkh/tty.git tty-next
> >
> >
> > in testcase: boot
> >
> > on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> >
> > caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> >
> >
> > +-------------------------------+------------+------------+
> > |                               | f3af1b68fc | 679193b7ba |
> > +-------------------------------+------------+------------+
> > | boot_successes                | 4          | 0          |
> > | boot_failures                 | 0          | 4          |
> > | BUG:spinlock_bad_magic_on_CPU | 0          | 4          |
> > +-------------------------------+------------+------------+
> >
> >
> > If you fix the issue, kindly add following tag
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> Thanks for the report. I didn't see it on real hardware though. Maybe
> because of timing (race?) differences.
> 
> Greg, I think the best is to revert the change until I will have better one.

Can you send me a revert patch with the reported-by: set up?

thanks,

greg k-h