futex_unlock_pi() hurts my brain and may cause application deadlock

Avoid futex_unlock_pi returning -EFAULT (which results in deadlock), by
clearing uval before jumping to retry_locked.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/futex.c b/kernel/futex.c
index 3415e9a..e8935b1 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1670,6 +1670,7 @@ pi_faulted:
                                         attempt);
                if (ret)
                        goto out;
+               uval = 0;
                goto retry_unlocked;
        }