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, 6 insertions, 0 deletions

diff --git a/net/socket.c b/net/socket.c
index 31105f9048a8..1310a82cbba7 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1222,6 +1222,12 @@ asmlinkage long sys_socket(int family, int type, int protocol)
         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;