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Date: Tue, 12 May 2009 21:21:45 +1000
From: Paul Mackerras <paulus@samba.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>, Ingo Molnar <mingo@elte.hu>,
       Corey Ashford <cjashfor@linux.vnet.ibm.com>,
       linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 3/5] perf_counter: rework ioctl()s
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Peter Zijlstra writes:

> Ah, so _IO() gets an unsigned long 3rd argument.
> _IOW() treats the 3rd arg as a (type __user *) and copies the bits over
> _IOR() copies the bits back out to userspace
> _IORW() does both

Yep.

> In which case the below should fix things up, no?

Looks good.

Paul.