Messages in this thread | | | Subject | Re: [PATCH 3/5] perf_counter: rework ioctl()s | From | Peter Zijlstra <> | Date | Tue, 12 May 2009 08:27:30 +0200 |
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On Tue, 2009-05-12 at 16:22 +1000, Paul Mackerras wrote: > Peter Zijlstra writes: > > > Hmm, are you saying that the 3rd argument to unlocked_ioctl is actually > > (void __user *) instead of unsigned long? > > He's saying (correctly) that using _IOR or _IOW implies that the ioctl > is going to read or write the memory location pointed to by the 3rd > argument to unlocked_ioctl. If the 3rd argument is just a number, not > an address, I believe you should use _IO.
Oh, somewhat confusing all this. Would be good to spell out these things somewhere. Documentation/ioctl/ seems less than helpful.
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