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Date: Mon, 14 Jul 2014 12:58:35 -0400
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Andy Lutomirski <luto@amacapital.net>, david.vrabel@citrix.com
Cc: "H. Peter Anvin" <hpa@zytor.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Is espfix64's double-fault thing OK on Xen?
Message-ID: <20140714165835.GA9969@laptop.dumpdata.com>
References: <CALCETrXrVNKNQtxncfOth5OqaSOC7KygerbB-+QQb4_VKESVsA@mail.gmail.com>
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On Wed, Jul 09, 2014 at 04:17:57PM -0700, Andy Lutomirski wrote:
> This part in __do_double_fault looks fishy:
> 
>     cmpl $__KERNEL_CS,CS(%rdi)
>     jne do_double_fault
> 
> Shouldn't that be:
> 
>     test $3,CS(%rdi)
>     jnz do_double_fault
> 

Let me rope in David, who was playing with that recently.

> --Andy