From 454eedb8901da895fb602998fa588cd62875d07d Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Tue, 10 Aug 2010 18:01:29 -0700 Subject: [PATCH] vfs: O_* bit numbers uniqueness check 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 Signed-off-by: Linus Torvalds --- fs/fcntl.c | 15 +++++++++++++-- include/asm-generic/fcntl.h | 4 ++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/fcntl.c b/fs/fcntl.c index 9d175d6..6769fd0 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -767,11 +767,22 @@ void kill_fasync(struct fasync_struct **fp, int sig, int band) } 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 --git a/include/asm-generic/fcntl.h b/include/asm-generic/fcntl.h index e3cbc38..a70b2d2 100644 --- a/include/asm-generic/fcntl.h +++ b/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 -- 2.7.4