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Date: Tue, 3 Apr 2018 11:29:03 +0200
From: Petr Mladek <pmladek@suse.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: syzbot <syzbot+d1fe9b7b917f2715c7d4@syzkaller.appspotmail.com>,
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        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>,
        x86@kernel.org, Dmitry Vyukov <dvyukov@google.com>,
        Eric Dumazet <edumazet@google.com>
Subject: Re: general protection fault in try_to_wake_up
Message-ID: <20180403092902.i2xg3dmdlcv477aw@pathway.suse.cz>
References: <000000000000f2c42e05688f3ab6@google.com>
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 <20180403091333.GZ4082@hirez.programming.kicks-ass.net>
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On Tue 2018-04-03 11:13:33, Peter Zijlstra wrote:
> On Tue, Apr 03, 2018 at 10:50:03AM +0200, Petr Mladek wrote:
> > raw_spin_lock() succeeded here. Therefore lockdep was still working
> > at this stage.
> 
> What does the success of raw_spin_lock() have to do with lockdep ?

It means that also lockdep succeeded there. Therefore the general
protection fault in __lock_acquire() was specific to the spinlock
taken by try_to_wake_up(). I though that it might had been an useful
information.

Anyway, the other replay from Dmitry suggested that it was a known
bug, see
https://lkml.kernel.org/r/CACT4Y+ZJ2QD7MPy4hB-M=mz2LuVu3bRbLg1QdY=z=+Su1QWMqg@mail.gmail.com

Best Regards,
Petr