Re: [iov_iter] 2418c34937: Initiating_system_reboot

[Oliver Sang]

hi, Al Viro,

On Wed, Apr 28, 2021 at 03:18:18AM +0000, Al Viro wrote:
> On Wed, Apr 28, 2021 at 10:37:47AM +0800, kernel test robot wrote:
> > 
> > 
> > Greeting,
> > 
> > FYI, we noticed the following commit (built with gcc-9):
> > 
> > commit: 2418c34937c42a30ef4bccd923ad664a89e1fbd4 ("iov_iter: optimize iov_iter_advance() for iovec and kvec")
> > https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git untested.iov_iter
> > 
> > 
> > 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):
> > 
> > 
> > +--------------------------+------------+------------+
> > |                          | c5f070c68e | 2418c34937 |
> > +--------------------------+------------+------------+
> > | boot_failures            | 0          | 11         |
> > | Initiating_system_reboot | 0          | 11         |
> > +--------------------------+------------+------------+
> > 
> > 
> > If you fix the issue, kindly add following tag
> > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
>  
> Could you run it with soft_panic=1 in command line?  Alternatively, some
> information about how to reproduce that without running hell knows what
> as root on host would be very welcome; I can't imagine a single reason
> for needing root to run qemu, to be honest...

not sure if this soft_panic=1 test is still useful, but from test, it seems
not generate more useful information (attached one for example).

and if you still want this test, could you help check our command line and
maybe supply further information how to enable it properly?

Attachment: dmesg-soft_panic.xz
Description: application/xz