Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755477Ab0AFHUf (ORCPT ); Wed, 6 Jan 2010 02:20:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752997Ab0AFHUe (ORCPT ); Wed, 6 Jan 2010 02:20:34 -0500 Received: from mga02.intel.com ([134.134.136.20]:49480 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751164Ab0AFHUd (ORCPT ); Wed, 6 Jan 2010 02:20:33 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,227,1262592000"; d="scan'208";a="481659348" Date: Wed, 6 Jan 2010 15:20:29 +0800 From: Wu Fengguang To: Eric Dumazet Cc: Andrew Morton , David Miller , Stephen Rothwell , Al Viro , Christoph Hellwig , Eric Paris , LKML , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH] fs: O_* bit numbers uniqueness check Message-ID: <20100106072029.GA25169@localhost> References: <20100106065526.GB11368@localhost> <4B443695.5090301@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4B443695.5090301@gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1388 Lines: 37 On Wed, Jan 06, 2010 at 03:07:01PM +0800, Eric Dumazet wrote: > Le 06/01/2010 07:55, Wu Fengguang a écrit : > > The O_* bit numbers are defined in 20+ arch/*, and hence can silently > > overlap. Add a boot time check to ensure the uniqueness as suggested > > by David Miller. > > > > CC: David Miller > > CC: Stephen Rothwell > > CC: Al Viro > > CC: Christoph Hellwig > > CC: Eric Paris > > Signed-off-by: Wu Fengguang > > --- > > { > > + /* please add new bits here to ensure allocation uniqueness */ > > + BUG_ON(20 != hweight32( > > + O_RDONLY | O_WRONLY | O_RDWR | > > + O_CREAT | O_EXCL | O_NOCTTY | > > + O_TRUNC | O_APPEND | O_NONBLOCK | > > + O_SYNC | FASYNC | O_DIRECT | > > + O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | > > + O_NOATIME | O_CLOEXEC | O_RANDOM | > > + FMODE_EXEC | FMODE_NONOTIFY)); > > + > > I cannot test it, but given O_RDONLY is 0, are you sure 20 bits are actually set ? Yes, I tested it. The tricky one is O_SYNC, which actually has two bits.. Thanks, Fengguang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/