[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>

diff --git a/kernel/futex.c b/kernel/futex.c
index b364e0026191caee9dd0ebee3a657e2f65b5c52e..93ef30ba209fc865c7507459f0995849d5d6e336 100644 (file)
--- 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))