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Date:   Wed, 28 Apr 2021 03:18:18 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     kernel test robot <oliver.sang@intel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org,
        lkp@lists.01.org, lkp@intel.com
Subject: Re: [iov_iter]  2418c34937: Initiating_system_reboot
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References: <20210428023747.GA13086@xsang-OptiPlex-9020>
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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@intel.com>
 
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...