eventfd: add a BUILD_BUG_ON() to ensure consistency between EFD_SEMAPHORE and the...

introduce a BUILD_BUG_ON to check that the EFD_SEMAPHORE is equal to its
definition in the uapi file, just like EFD_CLOEXEC and EFD_NONBLOCK.

Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Link: https://lore.kernel.org/r/tencent_0BAA2DEAF9208D49987457E6583F9BE79507@qq.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/eventfd.c b/fs/eventfd.c
index ad8186d47ba76062f1540835c9a5a0a64f560cd5..0252b71099fbca0f8fa50252a4239be1e637221c 100644 (file)
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -383,6 +383,7 @@ static int do_eventfd(unsigned int count, int flags)
        /* Check the EFD_* constants for consistency.  */
        BUILD_BUG_ON(EFD_CLOEXEC != O_CLOEXEC);
        BUILD_BUG_ON(EFD_NONBLOCK != O_NONBLOCK);
+       BUILD_BUG_ON(EFD_SEMAPHORE != (1 << 0));
 
        if (flags & ~EFD_FLAGS_SET)
                return -EINVAL;