36 lines
1.3 KiB
Diff
36 lines
1.3 KiB
Diff
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From 4845741567c819e587a0416e329a751af3111fd1 Mon Sep 17 00:00:00 2001
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Thu, 7 Sep 2017 12:38:47 +0200
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Subject: [PATCH 341/365] locking/rtmutex: don't drop the wait_lock twice
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Since the futex rework, __rt_mutex_start_proxy_lock() does no longer
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acquire the wait_lock so it must not drop it. Otherwise the lock is not
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only unlocked twice but also the preemption counter is underflown.
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It is okay to remove that line because this function does not disable
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interrupts nor does it acquire the ->wait_lock. The caller does this so it is
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wrong do it here (after the futex rework).
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Cc: stable-rt@vger.kernel.org #v4.9.18-rt14+
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Reported-by: Gusenleitner Klaus <gus@keba.com>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/locking/rtmutex.c | 1 -
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1 file changed, 1 deletion(-)
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diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
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index bb6a15456e62..1f3ceaf15588 100644
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--- a/kernel/locking/rtmutex.c
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+++ b/kernel/locking/rtmutex.c
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@@ -2312,7 +2312,6 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
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raw_spin_lock(&task->pi_lock);
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if (task->pi_blocked_on) {
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raw_spin_unlock(&task->pi_lock);
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- raw_spin_unlock_irq(&lock->wait_lock);
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return -EAGAIN;
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}
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task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
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--
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2.28.0
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