From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH][RT] futex: protect against pi_blocked_on corruption
 during requeue PI
Date: Tue, 13 Jul 2010 11:58:56 +0200 (CEST)
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Cc: "lkml, " <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@elte.hu>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	John Kacur <jkacur@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mike Galbraith <efault@gmx.de>,
	linux-rt-users <linux-rt-users@vger.kernel.org>
To: Darren Hart <dvhltc@us.ibm.com>
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On Tue, 13 Jul 2010, Darren Hart wrote:
> diff --git a/kernel/futex.c b/kernel/futex.c
> index a6cec32..c92978d 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -1336,6 +1336,9 @@ retry_private:
>  				requeue_pi_wake_futex(this, &key2, hb2);
>  				drop_count++;
>  				continue;
> +			} else if (ret == -EAGAIN) {
> +				/* Waiter woken by timeout or signal. */

  This leaks the pi_state.