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From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH RFC v2 6/6] KVM: introduce a new API for getting dirty
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Date: Fri, 23 Apr 2010 15:42:31 +0300
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To: Arnd Bergmann <arnd@arndb.de>
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On 04/23/2010 03:27 PM, Arnd Bergmann wrote:
>
>> Using a 64-bit integer avoids the problem (though perhaps not sufficient
>> for s390, Arnd?)
>>      
> When there is only a __u64 for the address, it will work on s390 as well,
> gcc is smart enough to clear the upper bit on a cast from long to pointer.
>    

Ah, much more convenient than compat_ioctl.  I assume it part of the 
ABI, not a gccism?

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.