Message-ID: <4B522B23.5090903@zytor.com>
Date: Sat, 16 Jan 2010 13:09:55 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Linus Torvalds <torvalds@linux-foundation.org>
CC: Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org,
       Thomas Gleixner <tglx@linutronix.de>,
       Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [GIT PULL] x86 fixes
References: <20100116170338.GA17175@elte.hu> <alpine.LFD.2.00.1001161233300.13231@localhost.localdomain> <4B522A61.2010504@zytor.com>
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On 01/16/2010 01:06 PM, H. Peter Anvin wrote:
> On 01/16/2010 12:34 PM, Linus Torvalds wrote:
>>
>>
>> On Sat, 16 Jan 2010, Ingo Molnar wrote:
>>>
>>> Cyrill Gorcunov (1):
>>>       x86: kernel_thread() -- initialize SS to a known state
>>
>> This looks bogus. Why does it do it only on x86-64?
>>
>> Either people care about SS or they don't (the answer, I suspect, is "they 
>> don't"). But if they care, we should do it on both 32-bit _and_ 64-bit, 
>> no?
>>
> 
> It is bogus -- it's basically Xen braindamage.
> 

As to why make it x86-64 only... it matches what the old assembly code
did.  We figured that that was the lowest risk option for unbreaking Xen.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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