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/signalfd.c b/fs/signalfd.c
index 5441a4bca772..9c39bc7f8431 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -211,6 +211,10 @@ asmlinkage long sys_signalfd4(int ufd, sigset_t __user *user_mask,
         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;