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From: Arnd Bergmann <arnd.bergmann@linaro.org>
Organization: Linaro Limited 
To: John Stultz <john.stultz@linaro.org>
Subject: Re: Fwd: [RFC][PATCH] staging: Fix build issues with new binder API
Date: Thu, 27 Feb 2014 20:15:23 +0100
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On Wednesday 26 February 2014, John Stultz wrote:
> The new 64bit binder API causes build issues on 32bit ARM
> due to the lack of 64bit __get_user_asm_* implementation.

It is impossible to implement this. Many have tried before.

> Until that implementation is done, remove the choice for
> 32bit ARM, automatically enabling the old 32bit binder
> protocol.
> 
> This can be reverted once a 64bit __get_user_asm_*
> implementation is merged.

I think the best solution is to use __copy_from_user for
the 64-bit access. You can wrap it in a helper function
if you want to speed up the native-word-size case.

	Arnd