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References: <20180103195056.837404126@linuxfoundation.org> <20180104234555.GA4143@roeck-us.net>
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 4 Jan 2018 15:58:37 -0800
Message-ID: <CA+55aFw0Srjop_Ag25wuOkKTdXn+XH0Ddhgiov-PwNB7Z9w05Q@mail.gmail.com>
Subject: Re: [PATCH 4.4 00/37] 4.4.110-stable review
To: Guenter Roeck <linux@roeck-us.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Shuah Khan <shuahkh@osg.samsung.com>, patches@kernelci.org,
        Ben Hutchings <ben.hutchings@codethink.co.uk>,
        lkft-triage@lists.linaro.org, stable <stable@vger.kernel.org>,
        Tao Wu <lepton@google.com>
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Sender: linux-kernel-owner@vger.kernel.org

On Thu, Jan 4, 2018 at 3:45 PM, Guenter Roeck <linux@roeck-us.net> wrote:
>
> [    0.721821] init: Corrupted page table at address 57b029b332e0
> [    0.722761] PGD 80000000bb238067 PUD bc36a067 PMD bc369067 PTE 45d2067
> [    0.722761] Bad pagetable: 000b [#1] PREEMPT SMP

Ok, it's unhappy because the RSVD bit is set in the error code.

And yeah, that seems to be due to NX in the pgd (nothing else is
certainly set), with presumably a virtual machine that doesn't support
it.

So I suspect your patch is indeed the right thing.

> The crash part of this problem may be solved with the following patch
> (thanks to Hugh for the hint). There is still another problem, though -
> with this patch applied, the qemu session aborts with "VCPU Shutdown
> request", whatever that means.

Presumably that is a triple fault.

That causes a reboot traditionally, and in a virtual environment that
would be approximated with a VCPU shutdown.

                Linus