From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [patch 2/5] vfs: O_* bit numbers uniqueness check Date: Mon, 24 May 2010 12:24:22 -0700 Message-ID: <201005241924.o4OJOM5D011496@imap1.linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Cc: linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, fengguang.wu@intel.com, davem@davemloft.net, eparis@redhat.com, hch@infradead.org, jamie@shareable.org, rdreier@cisco.com, schwab@linux-m68k.org, sfr@canb.auug.org.au To: viro@zeniv.linux.org.uk Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:60164 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754654Ab0EXTZb (ORCPT ); Mon, 24 May 2010 15:25:31 -0400 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Wu Fengguang 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. Signed-off-by: Wu Fengguang 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: Andrew Morton --- fs/fcntl.c | 15 +++++++++++++-- include/asm-generic/fcntl.h | 4 ++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff -puN fs/fcntl.c~vfs-o_-bit-numbers-uniqueness-check fs/fcntl.c --- a/fs/fcntl.c~vfs-o_-bit-numbers-uniqueness-check +++ a/fs/fcntl.c @@ -762,11 +762,22 @@ 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(19 - 1 /* for O_RDONLY being 0 */ != 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 | + FMODE_EXEC + )); + 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) diff -puN include/asm-generic/fcntl.h~vfs-o_-bit-numbers-uniqueness-check include/asm-generic/fcntl.h --- a/include/asm-generic/fcntl.h~vfs-o_-bit-numbers-uniqueness-check +++ a/include/asm-generic/fcntl.h @@ -11,6 +11,10 @@ * -Eric Paris */ +/* + * When introducing new O_* bits, please check its uniqueness in fcntl_init(). + */ + #define O_ACCMODE 00000003 #define O_RDONLY 00000000 #define O_WRONLY 00000001 _