| From b987e27fbe51f73d2875a2cd4e49dd756e15bffa Mon Sep 17 00:00:00 2001 |
| From: Steven Rostedt <rostedt@goodmis.org> |
| Date: Thu, 1 Mar 2012 13:55:29 -0500 |
| Subject: [PATCH 232/262] futex/rt: Fix possible lockup when taking pi_lock in |
| proxy handler |
| |
| 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> |
| Cc: Carsten Emde <C.Emde@osadl.org> |
| Cc: John Kacur <jkacur@redhat.com> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Clark Williams <clark.williams@gmail.com> |
| Cc: stable-rt@vger.kernel.org |
| Link: http://lkml.kernel.org/r/20120301190345.165160680@goodmis.org |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| --- |
| kernel/rtmutex.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c |
| index 921c90b..3bff726 100644 |
| --- a/kernel/rtmutex.c |
| +++ b/kernel/rtmutex.c |
| @@ -1365,14 +1365,14 @@ 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); |
| -- |
| 1.7.10.4 |
| |
