Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754615Ab0AINwd (ORCPT ); Sat, 9 Jan 2010 08:52:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754553Ab0AINwc (ORCPT ); Sat, 9 Jan 2010 08:52:32 -0500 Received: from mga11.intel.com ([192.55.52.93]:44506 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752410Ab0AINwb (ORCPT ); Sat, 9 Jan 2010 08:52:31 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,246,1262592000"; d="scan'208";a="529871664" Date: Sat, 9 Jan 2010 21:52:19 +0800 From: Wu Fengguang To: Christoph Hellwig Cc: Andrew Morton , David Miller , Stephen Rothwell , Al Viro , Eric Paris , LKML , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH] fs: O_* bit numbers uniqueness check Message-ID: <20100109135219.GD20015@localhost> References: <20100106065526.GB11368@localhost> <20100106154814.GA5172@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100106154814.GA5172@infradead.org> 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: 2990 Lines: 84 On Wed, Jan 06, 2010 at 11:48:14PM +0800, Christoph Hellwig wrote: > On Wed, Jan 06, 2010 at 02:55:26PM +0800, Wu Fengguang wrote: > > 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. > > The right fix is to stop overlyaing the FMODE_ flags into the O_ > namespace. Al has been working towards this. I thinks they are orthogonal problems -- this patch watches for the possible conflicting O_* in so many archs. Anyway here is the new version without the FMODE_ and O_RANDOM. Thanks, Fengguang --- fs: O_* bit numbers uniqueness check 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. v4: use the nice hweight_long() as suggested by Jamie split O_SYNC to (__O_SYNC | O_DSYNC) as suggested by Andreas take away FMODE_* and O_RANDOM v3: change to BUILD_BUG_ON() as suggested by Roland CC: David Miller CC: Stephen Rothwell CC: Al Viro CC: Christoph Hellwig CC: Eric Paris CC: Roland Dreier CC: Jamie Lokier CC: Andreas Schwab Signed-off-by: Wu Fengguang --- fs/fcntl.c | 14 ++++++++++++-- include/asm-generic/fcntl.h | 2 ++ 2 files changed, 14 insertions(+), 2 deletions(-) --- linux.orig/fs/fcntl.c 2010-01-09 11:02:57.000000000 +0800 +++ linux/fs/fcntl.c 2010-01-09 21:36:16.000000000 +0800 @@ -709,11 +709,21 @@ void kill_fasync(struct fasync_struct ** } EXPORT_SYMBOL(kill_fasync); -static int __init fasync_init(void) +static int __init fcntl_init(void) { + /* please add new bits here to ensure allocation uniqueness */ + BUILD_BUG_ON(17 != hweight_long( + O_RDONLY | O_WRONLY | O_RDWR | + O_CREAT | O_EXCL | O_NOCTTY | + O_TRUNC | O_APPEND | O_NONBLOCK | + __O_SYNC | O_DSYNC | FASYNC | + O_DIRECT | O_LARGEFILE | O_DIRECTORY | + O_NOFOLLOW | O_NOATIME | O_CLOEXEC + )); + fasync_cache = kmem_cache_create("fasync_cache", sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL); return 0; } -module_init(fasync_init) +module_init(fcntl_init) --- linux.orig/include/asm-generic/fcntl.h 2010-01-09 11:02:57.000000000 +0800 +++ linux/include/asm-generic/fcntl.h 2010-01-09 12:23:17.000000000 +0800 @@ -4,6 +4,8 @@ #include /* + * When introducing new O_* bits, please check its uniqueness in fcntl_init(). + * * FMODE_EXEC is 0x20 * FMODE_NONOTIFY is 0x1000000 * These cannot be used by userspace O_* until internal and external open -- 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/