From: "H. Peter Anvin" <hpa@zytor.com>
To: Andy Lutomirski <luto@amacapital.net>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Is espfix64's double-fault thing OK on Xen?
Date: Mon, 14 Jul 2014 10:04:03 -0700 [thread overview]
Message-ID: <53C40D83.3090501@zytor.com> (raw)
In-Reply-To: <CALCETrXrVNKNQtxncfOth5OqaSOC7KygerbB-+QQb4_VKESVsA@mail.gmail.com>
On 07/09/2014 04:17 PM, 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
>
No, it should be fine. The *only* case where we need to do the espfix
magic is when we are on __KERNEL_CS.
-hpa
next prev parent reply other threads:[~2014-07-14 17:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-09 23:17 Is espfix64's double-fault thing OK on Xen? Andy Lutomirski
2014-07-14 16:58 ` Konrad Rzeszutek Wilk
2014-07-14 17:04 ` H. Peter Anvin [this message]
2014-07-14 17:11 ` Andy Lutomirski
2014-07-14 17:15 ` Andy Lutomirski
2014-07-14 21:31 ` Andy Lutomirski
2014-07-14 21:35 ` Andy Lutomirski
2014-07-14 22:23 ` H. Peter Anvin
2014-07-15 2:46 ` Andy Lutomirski
2014-07-15 3:20 ` Andy Lutomirski
2014-07-15 4:14 ` H. Peter Anvin
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