[PATCH] schedule removal of FUTEX_FD

Apparently FUTEX_FD is unfixably racy and nothing uses it (or if it does, it
shouldn't).

Add a warning printk, give any remaining users six months to migrate off it.

Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index b364e0026191..93ef30ba209f 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1507,6 +1507,13 @@ static int futex_fd(u32 __user *uaddr, int signal)
         struct futex_q *q;
         struct file *filp;
         int ret, err;
+        static unsigned long printk_interval;
+
+        if (printk_timed_ratelimit(&printk_interval, 60 * 60 * 1000)) {
+                printk(KERN_WARNING "Process `%s' used FUTEX_FD, which "
+                        "will be removed from the kernel in June 2007\n",
+                        current->comm);
+        }
 
         ret = -EINVAL;
         if (!valid_signal(signal))