From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andreas Gruenbacher <agruen@suse.de>
Subject: Re: [AppArmor 37/41] AppArmor: Main Part
Date: Fri, 13 Apr 2007 10:48:17 +0200
Message-ID: <200704131048.17846.agruen@suse.de>
References: <20070412090809.917795000@suse.de> <20070412090848.752885000@suse.de> <20070412113723.2ec7e4f0@the-village.bc.nu>
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Cc: jjohansen@suse.de, linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, chrisw@sous-sol.org
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
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On Thursday 12 April 2007 12:37, Alan Cox wrote:
> > +		if (PTR_ERR(sa->name) == -ENOENT && (check & AA_CHECK_FD))
> > +			denied_mask = 0;
>
> Now there is an interesting question. Is PTR_ERR() safe for kernel
> pointers on all platforms or just for user ones ?

It's used for kernel pointers all over the place and mmap also mixes user 
addresses with -Exxx, so it's definitely supposed to work. I'm not sure how 
exactly the topmost page is kept from getting mapped.

Andreas