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 <fengguang.wu@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Jamie Lokier <jamie@shareable.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Wu Fengguang 2010-08-10 18:01:29 -07:00 committed by Linus Torvalds
parent 58939473ba
commit 454eedb890
2 changed files with 17 additions and 2 deletions

View file

@ -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)

View file

@ -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