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.

[[e-mail]: fix alpha]
Signed-off-by: Ulrich Drepper <[e-mail]>
Acked-by: Davide Libenzi <[e-mail]>
Cc: Michael Kerrisk <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/eventfd.c

···
 	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;
 

fs/eventpoll.c

···
 	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;
 

fs/inotify_user.c

···
 	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;
 

fs/signalfd.c

···
 	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;
 

fs/timerfd.c

···
 	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 &&

net/socket.c

···
 	struct socket *sock;
 	int flags;
 
+	/* Check the SOCK_* constants for consistency.  */
+	BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
+	BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
+	BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
+	BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
+
 	flags = type & ~SOCK_TYPE_MASK;
 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
 		return -EINVAL;