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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
	linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Carsten Emde <C.Emde@osadl.org>, John Kacur <jkacur@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Clark Williams <clark.williams@gmail.com>
Subject: [PATCH RT 2/9][RFC] [PATCH 2/9] futex/rt: Fix possible lockup when taking pi_lock in proxy handler
Date: Thu, 01 Mar 2012 13:55:29 -0500	[thread overview]
Message-ID: <20120301190345.165160680@goodmis.org> (raw)
In-Reply-To: 20120301185527.064629423@goodmis.org

[-- Attachment #1: 0002-futex-rt-Fix-possible-lockup-when-taking-pi_lock-in-.patch --]
[-- Type: text/plain, Size: 1090 bytes --]

When taking the pi_lock, we must disable interrupts because the
pi_lock can also be taken in an interrupt handler.

Use raw_spin_lock_irq() instead of raw_spin_lock().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/rtmutex.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 9850dc0..b525158 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -1373,14 +1373,14 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
 	 * PI_REQUEUE_INPROGRESS, so that if the task is waking up
 	 * it will know that we are in the process of requeuing it.
 	 */
-	raw_spin_lock(&task->pi_lock);
+	raw_spin_lock_irq(&task->pi_lock);
 	if (task->pi_blocked_on) {
-		raw_spin_unlock(&task->pi_lock);
+		raw_spin_unlock_irq(&task->pi_lock);
 		raw_spin_unlock(&lock->wait_lock);
 		return -EAGAIN;
 	}
 	task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
-	raw_spin_unlock(&task->pi_lock);
+	raw_spin_unlock_irq(&task->pi_lock);
 #endif
 
 	ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
-- 
1.7.3.4



  parent reply	other threads:[~2012-03-01 19:03 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-01 18:55 [PATCH RT 0/9][RFC] rt: Fix hotplugging and other nasties Steven Rostedt
2012-03-01 18:55 ` [PATCH RT 1/9][RFC] [PATCH 1/9] timer: Fix hotplug for -rt Steven Rostedt
2012-03-01 18:55 ` Steven Rostedt [this message]
2012-03-01 18:55 ` [PATCH RT 3/9][RFC] [PATCH 3/9] lglock/rt: Use non-rt for_each_cpu() in -rt code Steven Rostedt
2012-03-02  7:25   ` Srivatsa S. Bhat
2012-03-02 14:20     ` Steven Rostedt
2012-03-01 18:55 ` [PATCH RT 4/9][RFC] [PATCH 4/9] rtmutex: Add new mutex_lock_savestate() API Steven Rostedt
2012-03-01 18:55 ` [PATCH RT 5/9][RFC] [PATCH 5/9] ring-buffer/rt: Check for irqs disabled before grabbing reader lock Steven Rostedt
2012-03-01 18:55 ` [PATCH RT 6/9][RFC] [PATCH 6/9] sched/rt: Fix wait_task_interactive() to test rt_spin_lock state Steven Rostedt
2012-03-01 18:55 ` [PATCH RT 7/9][RFC] [PATCH 7/9] cpu/rt: Rework cpu down for PREEMPT_RT Steven Rostedt
2012-03-02 14:52   ` Thomas Gleixner
2012-03-02 15:11     ` Steven Rostedt
2012-03-02 15:15     ` Steven Rostedt
2012-03-02 15:20       ` Thomas Gleixner
2012-03-02 15:36         ` Steven Rostedt
2012-03-02 15:39           ` Steven Rostedt
2012-03-02 15:40           ` Steven Rostedt
2012-03-02 15:51           ` Thomas Gleixner
2012-03-01 18:55 ` [PATCH RT 8/9][RFC] [PATCH 8/9] workqueue: Revert workqueue: Fix PF_THREAD_BOUND abuse Steven Rostedt
2012-03-01 18:55 ` [PATCH RT 9/9][RFC] [PATCH 9/9] workqueue: Revert workqueue: Fix cpuhotplug trainwreck Steven Rostedt

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