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From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 10 Jul 2017 17:30:38 -0700
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Subject: Re: KASAN vs. boot-time switching between 4- and 5-level paging
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andy Lutomirski <luto@kernel.org>, Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        "x86@kernel.org" <x86@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
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On Mon, Jul 10, 2017 at 2:24 PM, Kirill A. Shutemov
<kirill@shutemov.name> wrote:
> On Mon, Jul 10, 2017 at 01:07:13PM -0700, Andy Lutomirski wrote:
>> Can you give the disassembly of the backtrace lines?  Blaming the
>> .endr doesn't make much sense to me.
>
> I don't have backtrace. It's before printk() is functional. I only see
> triple fault and reboot.
>
> I had to rely on qemu tracing and gdb.

Can you ask GDB or objtool to disassemble around those addresses?  Can
you also attach the big dump that QEMU throws out that shows register
state?  In particular, CR2, CR3, and CR4 could be useful.

--Andy