Date: Tue, 27 Oct 2009 22:29:55 -0700 (PDT)
Message-Id: <20091027.222955.05560476.davem@davemloft.net>
To: andi@firstfloor.org
Cc: airlied@gmail.com, linux-kernel@vger.kernel.org,
       dri-devel@lists.sourceforge.net, arnd@arndb.de
Subject: Re: is avoiding compat ioctls possible?
From: David Miller <davem@davemloft.net>
In-Reply-To: <20091028043611.GK7744@basil.fritz.box>
References: <87hbtkjkki.fsf@basil.nowhere.org>
	<20091027.203709.27104760.davem@davemloft.net>
	<20091028043611.GK7744@basil.fritz.box>
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From: Andi Kleen <andi@firstfloor.org>
Date: Wed, 28 Oct 2009 05:36:11 +0100

> On Tue, Oct 27, 2009 at 08:37:09PM -0700, David Miller wrote:
>> On sparc64, in order to make debugging easier, we trap any time
>> the kernel does a userspace access to a compat task and any
>> of the upper 32-bits are non-zero.
> 
> Interesting. That definitely means Dave needs a special path.

I wouldn't call it special, the rule is that any userland pointer
has to either go through a syscall argument register or one
of the compat_*() accessor routines :-)
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