From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: [PATCH 2/4] vfs: O_* bit numbers uniqueness check Date: Sun, 07 Feb 2010 11:28:07 +0800 Message-ID: <20100207034223.615803205@intel.com> References: <20100207032805.769788305@intel.com> Cc: Al Viro , David Miller , Stephen Rothwell , Al Viro , Christoph Hellwig , Eric Paris , Roland Dreier , Jamie Lokier , Andreas Schwab , Wu Fengguang To: Andrew Morton Return-path: Received: from mga01.intel.com ([192.55.52.88]:16528 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753614Ab0BGDnu (ORCPT ); Sat, 6 Feb 2010 22:43:50 -0500 CC: "H. Peter Anvin" CC: Borislav Petkov CC: Peter Zijlstra cc: Cc: LKML Content-Disposition: inline; filename=fcntl-bit-check.patch Sender: linux-fsdevel-owner@vger.kernel.org List-ID: The O_* bit numbers are defined in 20+ arch/*, and can silently overlap. Add a compile time check to ensure the uniqueness as suggested by David Miller. v5: use Peter's HWEIGHT32() v4: use the nice hweight_long() (suggested by Jamie) split O_SYNC to (__O_SYNC | O_DSYNC) (suggested by Andreas) take away the FMODE_* and O_RANDOM bits v3: change to BUILD_BUG_ON() (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 2010-01-30 18:09:33.000000000 +0800 +++ linux/fs/fcntl.c 2010-02-07 11:17:36.000000000 +0800 @@ -741,11 +741,21 @@ 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 != HWEIGHT32( + 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 2010-02-07 11:17:04.000000000 +0800 +++ linux/include/asm-generic/fcntl.h 2010-02-07 11:17:06.000000000 +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