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authorWu Fengguang <fengguang.wu@intel.com>2010-08-11 03:01:29 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-11 17:59:02 +0200
commit454eedb8901da895fb602998fa588cd62875d07d (patch)
tree8ac0f8fead7c689dec077fb43efe3dbe3eab2e29
parentvfs: improve comment describing fget_light() (diff)
downloadlinux-454eedb8901da895fb602998fa588cd62875d07d.tar.xz
linux-454eedb8901da895fb602998fa588cd62875d07d.zip
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>
-rw-r--r--fs/fcntl.c15
-rw-r--r--include/asm-generic/fcntl.h4
2 files changed, 17 insertions, 2 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 9d175d623aab..6769fd0f35b8 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 e3cbc38bdcc2..a70b2d2bfc14 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