fanotify_user: use upper_32_bits() to verify mask

I don't see an obvious reason why the upper 32 bit check needs to be
open-coded this way. Switch to upper_32_bits() which is more idiomatic and
should conceptually be the same check.

Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210325083742.2334933-1-brauner@kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 65142b1..71fefb3 100644 (file)
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -1250,7 +1250,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
                 __func__, fanotify_fd, flags, dfd, pathname, mask);
 
        /* we only use the lower 32 bits as of right now. */
-       if (mask & ((__u64)0xffffffff << 32))
+       if (upper_32_bits(mask))
                return -EINVAL;
 
        if (flags & ~FANOTIFY_MARK_FLAGS)