Date: Tue, 27 Oct 2009 20:43:10 -0700 (PDT)
Message-Id: <20091027.204310.170866512.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: <20091028033455.GF7744@basil.fritz.box>
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	<20091028033455.GF7744@basil.fritz.box>
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From: Andi Kleen <andi@firstfloor.org>
Date: Wed, 28 Oct 2009 04:34:55 +0100

> On Wed, Oct 28, 2009 at 01:28:10PM +1000, Dave Airlie wrote:
>> Well this was what I was trying to gather, so maybe I just need to write
>> something up to state that compat_ioctl is always required for new ioctls
>> that pass pointers or 64-bit values hiding pointers, so more people
>> don't make this mistake going forward. I can say when we inquired about this
>> 2 or so years ago when designing kms I didn't get this answer, which is a pity.
> 
> Right now you could probably ignore it (if you document it), since
> there are no non s390 architectures with this problem, just
> prepare mentally that you might need to revisit this at some point.

You can't ignore it on sparc64, it already OOPS's, and I refuse to
live with that "if (is_compat_task())" masking hack, no way.

We designed portable interfaces for doing this stuff, please use it.
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