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. 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: Wu Fengguang --- fs/fcntl.c | 14 ++++++++++++-- include/asm-generic/fcntl.h | 4 ++++ 2 files changed, 16 insertions(+), 2 deletions(-) --- linux-mm.orig/fs/fcntl.c 2010-03-16 09:18:28.000000000 +0800 +++ linux-mm/fs/fcntl.c 2010-03-16 09:32:17.000000000 +0800 @@ -739,11 +739,21 @@ 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-mm.orig/include/asm-generic/fcntl.h 2010-03-16 09:31:16.000000000 +0800 +++ linux-mm/include/asm-generic/fcntl.h 2010-03-16 09:33:30.000000000 +0800 @@ -3,6 +3,10 @@ #include +/* + * When introducing new O_* bits, please check its uniqueness in fcntl_init(). + */ + #define O_ACCMODE 00000003 #define O_RDONLY 00000000 #define O_WRONLY 00000001 -- 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/