flag parameters: check magic constants

This patch adds test that ensure the boundary conditions for the various
constants introduced in the previous patches is met.  No code is generated.

[akpm@linux-foundation.org: fix alpha]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/timerfd.c b/fs/timerfd.c
index 75d44efe346c..c502c60e4f54 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -184,6 +184,10 @@ asmlinkage long sys_timerfd_create(int clockid, int flags)
         int ufd;
         struct timerfd_ctx *ctx;
 
+        /* Check the TFD_* constants for consistency.  */
+        BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC);
+        BUILD_BUG_ON(TFD_NONBLOCK != O_NONBLOCK);
+
         if (flags & ~(TFD_CLOEXEC | TFD_NONBLOCK))
                 return -EINVAL;
         if (clockid != CLOCK_MONOTONIC &&