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Date:   Wed, 3 May 2023 11:54:20 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Dmitry Vyukov <dvyukov@google.com>
Cc:     syzbot <syzbot+0827f43974813b74e6db@syzkaller.appspotmail.com>,
        bristot@redhat.com, bsegall@google.com, dietmar.eggemann@arm.com,
        hannes@cmpxchg.org, juri.lelli@redhat.com,
        linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com,
        peterz@infradead.org, rostedt@goodmis.org, surenb@google.com,
        syzkaller-bugs@googlegroups.com, vincent.guittot@linaro.org,
        vschneid@redhat.com,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [syzbot] upstream boot error: BUG: unable to handle kernel NULL
 pointer dereference in psi_task_switch
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On Wed, May 03, 2023 at 12:38:19PM +0200, Dmitry Vyukov wrote:
> On Wed, 3 May 2023 at 12:34, Russell King (Oracle)
> <linux@armlinux.org.uk> wrote:
> >
> > On Tue, May 02, 2023 at 08:37:15AM +0200, Dmitry Vyukov wrote:
> > > On Mon, 1 May 2023 at 18:43, syzbot
> > > <syzbot+0827f43974813b74e6db@syzkaller.appspotmail.com> wrote:
> > > >
> > > > Hello,
> > > >
> > > > syzbot found the following issue on:
> > > >
> > > > HEAD commit:    89d77f71f493 Merge tag 'riscv-for-linus-6.4-mw1' of git://..
> > > > git tree:       upstream
> > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1113550c280000
> > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=4cc65ccad523b604
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=0827f43974813b74e6db
> > > > compiler:       arm-linux-gnueabi-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > > > userspace arch: arm
> > > >
> > > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > > Reported-by: syzbot+0827f43974813b74e6db@syzkaller.appspotmail.com
> > >
> > > +arm mailing list
> > >
> > > Kernel started falling apart on arm during boot in various strange ways.
> >
> > Are these all the same hardware platform? If so, please check the
> > hardware with a known working kernel. These look like spurious failts
> > caused possibly the hardware platform failing.
> 
> It happens in the same qemu that used to work before. So "hardware" is
> presumably working.

I have no other ideas based on the incomplete information provided
(due to the initial oops triggering a subsequent oops while trying to
print the register "information".) And I have no suggestions how to
debug it further. Sorry.

-- 
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