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Date: Wed, 30 Apr 2003 19:41:24 -0700
From: Andrew Morton <akpm@digeo.com>
To: Ben Collins <bcollins@debian.org>
Cc: torvalds@transmeta.com, pavel@ucw.cz, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Fix NULL handler for compat_ioctl
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Ben Collins <bcollins@debian.org> wrote:
>
> -	t->handler = handler; 
> +	if (!handler)
> +		t->handler = (void *)sys_ioctl;
> +	else
> +		t->handler = handler; 

Is that safe?

- sys_ioctl takes three args, but this vector is going to be called with
  four.  That's making assumptions about arg passing conventions which may
  not be true.

- sys_ioctl() is asmlinkage, but the caller of this vector doesn't know
  that.  Arguments may get put in the wrong place.

Is a little wrapper function needed?