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>
diff --git a/fs/eventfd.c b/fs/eventfd.c
index 3ed4466..08bf558 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -203,6 +203,10 @@
 	int fd;
 	struct eventfd_ctx *ctx;
 
+	/* Check the EFD_* constants for consistency.  */
+	BUILD_BUG_ON(EFD_CLOEXEC != O_CLOEXEC);
+	BUILD_BUG_ON(EFD_NONBLOCK != O_NONBLOCK);
+
 	if (flags & ~(EFD_CLOEXEC | EFD_NONBLOCK))
 		return -EINVAL;
 
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 3fd4014..2fdad42 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1051,6 +1051,9 @@
 	int error, fd = -1;
 	struct eventpoll *ep;
 
+	/* Check the EPOLL_* constant for consistency.  */
+	BUILD_BUG_ON(EPOLL_CLOEXEC != O_CLOEXEC);
+
 	if (flags & ~EPOLL_CLOEXEC)
 		return -EINVAL;
 
diff --git a/fs/inotify_user.c b/fs/inotify_user.c
index dc7e1f6..fe79c25d 100644
--- a/fs/inotify_user.c
+++ b/fs/inotify_user.c
@@ -574,6 +574,10 @@
 	struct file *filp;
 	int fd, ret;
 
+	/* Check the IN_* constants for consistency.  */
+	BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
+	BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
+
 	if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
 		return -EINVAL;
 
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 5441a4b..9c39bc7 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -211,6 +211,10 @@
 	sigset_t sigmask;
 	struct signalfd_ctx *ctx;
 
+	/* Check the SFD_* constants for consistency.  */
+	BUILD_BUG_ON(SFD_CLOEXEC != O_CLOEXEC);
+	BUILD_BUG_ON(SFD_NONBLOCK != O_NONBLOCK);
+
 	if (flags & ~(SFD_CLOEXEC | SFD_NONBLOCK))
 		return -EINVAL;
 
diff --git a/fs/timerfd.c b/fs/timerfd.c
index 75d44ef..c502c60 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -184,6 +184,10 @@
 	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 &&