From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: high_memory address in /proc/dri/*/vma Date: Tue, 20 Dec 2011 19:03:54 +0000 Message-ID: <20111220190354.GC20752@decadent.org.uk> References: <20111220000939.GB20752@decadent.org.uk> <20111220163213.GB3883@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from shadbolt.e.decadent.org.uk (shadbolt.e.decadent.org.uk [88.96.1.126]) by gabe.freedesktop.org (Postfix) with ESMTP id 484299E80D for ; Tue, 20 Dec 2011 11:03:59 -0800 (PST) Content-Disposition: inline In-Reply-To: <20111220163213.GB3883@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Daniel Vetter Cc: Dave Airlie , Kees Cook , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On Tue, Dec 20, 2011 at 05:32:13PM +0100, Daniel Vetter wrote: > On Tue, Dec 20, 2011 at 12:09:39AM +0000, Ben Hutchings wrote: > > [Re-sent to the right address, I hope.] > > > > Kees, in commit 01e2f533a234dc62d16c0d3d4fb9d71cf1ce50c3 ("drm: do not > > leak kernel addresses via /proc/dri/*/vma") you changed the logging of > > high_memory: > > > > - seq_printf(m, "vma use count: %d, high_memory = %p, 0x%08llx\n", > > + seq_printf(m, "vma use count: %d, high_memory = %pK, 0x%pK\n", > > atomic_read(&dev->vma_count), > > - high_memory, (u64)virt_to_phys(high_memory)); > > + high_memory, (void *)virt_to_phys(high_memory)); > > > > This doesn't make sense because the physical address may be truncated > > (in theory at least). > > > > I think it would make more sense to make this entire file readable by > > root only, but I don't know whether anything depends on being able to > > read it. Its existence is conditional on DRM_DEBUG_CODE != 0 but that > > is always true at the moment. > > Afaik (and I've done quite some code history checking) the proc files are > not relied upon by userspace (up to about 10 years back). Patch to kill > them all is pending and should hit either 3.3 or 3.4. Great, that'll be one more warning gone. :-) Ben. -- Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camus