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Date: Wed, 28 Jul 2004 16:34:40 -0700
From: Andrew Morton <akpm@osdl.org>
To: Johannes Stezenbach <js@convergence.de>
Cc: viro@parcelfarce.linux.theplanet.co.uk, linux-kernel@vger.kernel.org
Subject: Re: 2.6.8-rc2-mm1
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Johannes Stezenbach <js@convergence.de> wrote:
>
> This is a hack introduced by someone years ago. The "pointer" is
> actually an integer argument, e.g. in include/linux/dvb/audio.h:
> 
> #define AUDIO_SET_MUTE             _IO('o', 6)
> 
> actually takes an integer argument (!0 mute, 0 unmute), so one can write
> 
> 	if (ioctl(fd, AUDIO_SET_MUTE, 1) == -1)
> 		perror("mute");

Is it a boolean argument?

If so, we could change the code to do

	parg = (void *)(arg ? 1 : 0);

so if someone dereferences it they'll get a nice oops.