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Date: Wed, 17 Mar 2010 07:32:06 -0700
From: Richard Henderson <rth@twiddle.net>
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Subject: Re: [Qemu-devel] [PATCH 0/6] Multi-level page tables and userland
	mapping fixes, v3
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To: Riku Voipio <riku.voipio@iki.fi>
Cc: Martin Mohring <martin.mohring@opensuse.org>, Aurelien Jarno <aurelien@aurel32.net>, qemu-devel@nongnu.org, =?UTF-8?B?SmFuLVNpbW9uIE3DtmxsZXI=?= <dl9pf@gmx.de>

On 03/17/2010 04:48 AM, Riku Voipio wrote:
>>> page_check_range:
>>>
>>> -    if (start + len < start)
>>> -        /* we've wrapped around */
>>> ...
>>> +    if (start + len - 1 < start) {
>>> +        /* We've wrapped around.  */
>>>
>>> This now blows up with len = 0;
> 
>> Confirmed. A quick test with  if (len > 0) around and ldconfig.real runs.
> 
> Richard, would you be ok with that change? Or should we rather have explicit 
> 
> if (len == 0) return 0;

My personal preference is 

  if (len != 0 && start + len - 1 < start)

but don't let that stop anyone checking in any correct variant.


r~