From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755458AbdESQxE (ORCPT ); Fri, 19 May 2017 12:53:04 -0400 Received: from mail-pf0-f177.google.com ([209.85.192.177]:35399 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750831AbdESQxC (ORCPT ); Fri, 19 May 2017 12:53:02 -0400 Date: Fri, 19 May 2017 09:52:59 -0700 From: Matthias Kaehlcke To: Stephen Smalley Cc: Paul Moore , James Morris , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov Subject: Re: [PATCH] selinux: Mark array 'labeling_behaviors' as __maybe_unused Message-ID: <20170519165259.GJ141096@google.com> References: <20170518190759.28560-1-mka@chromium.org> <1495208719.2209.12.camel@tycho.nsa.gov> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1495208719.2209.12.camel@tycho.nsa.gov> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org El Fri, May 19, 2017 at 11:45:19AM -0400 Stephen Smalley ha dit: > On Fri, 2017-05-19 at 11:09 -0400, Paul Moore wrote: > > On Thu, May 18, 2017 at 3:07 PM, Matthias Kaehlcke > > wrote: > > > The array is only referenced in an ARRAY_SIZE() statement. Adding > > > the > > > attribute fixes the following warning when building with clang: > > > > > > security/selinux/hooks.c:338:20: error: variable > > > 'labeling_behaviors' > > >     is not needed and will not be emitted > > >     [-Werror,-Wunneeded-internal-declaration] > > > > > > Signed-off-by: Matthias Kaehlcke > > > --- > > >  security/selinux/hooks.c | 2 +- > > >  1 file changed, 1 insertion(+), 1 deletion(-) > > > > The fact that we only reference labeling_behaviors in one spot, and > > even then we only use it as a parameter to ARRAY_SIZE(), makes me > > believe we may be able to get rid of labeling_behaviors and use > > SECURITY_FS_USE_MAX in its place. > > > > Anyone working on any patches which make use of labeling_behaviors? > > I think you could just remove both the array and the code that > referenced it; it only made sense before commit > 2088d60e3b2f53d0c9590a0202eeff85b288b1eb. We already check that the > policy doesn't contain any behavior > SECURITY_FS_USE_MAX during policy > load, so this cannot occur (modulo memory corruption), and it was only > there to make sure we didn't try to dereference off the end of the > array prior to the aforementioned commit. Thanks for your comments. I will send out a patch that removes the array shortly. Matthias