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>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Julia Cartwright <julia@ni.com>,
Daniel Wagner <daniel.wagner@siemens.com>,
tom.zanussi@linux.intel.com, Alex Shi <alex.shi@linaro.org>,
Gusenleitner Klaus <gus@keba.com>
Subject: [PATCH RT 14/15] locking/rtmutex: dont drop the wait_lock twice
Date: Fri, 01 Dec 2017 10:50:13 -0500 [thread overview]
Message-ID: <20171201155030.362565579@goodmis.org> (raw)
In-Reply-To: 20171201154959.375846909@goodmis.org
[-- Attachment #1: 0014-locking-rtmutex-don-t-drop-the-wait_lock-twice.patch --]
[-- Type: text/plain, Size: 1256 bytes --]
4.9.65-rt57-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Since the futex rework, __rt_mutex_start_proxy_lock() does no longer
acquire the wait_lock so it must not drop it. Otherwise the lock is not
only unlocked twice but also the preemption counter is underflown.
It is okay to remove that line because this function does not disable
interrupts nor does it acquire the ->wait_lock. The caller does this so it is
wrong do it here (after the futex rework).
Cc: rt-stable@vger.kernel.org #v4.9.18-rt14+
Reported-by: Gusenleitner Klaus <gus@keba.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/locking/rtmutex.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 5dbf6789383b..3a8b5d44aaf8 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -2312,7 +2312,6 @@ int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
raw_spin_lock(&task->pi_lock);
if (task->pi_blocked_on) {
raw_spin_unlock(&task->pi_lock);
- raw_spin_unlock_irq(&lock->wait_lock);
return -EAGAIN;
}
task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
--
2.13.2
next prev parent reply other threads:[~2017-12-01 15:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-01 15:49 [PATCH RT 00/15] Linux 4.9.65-rt57-rc1 Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 01/15] Revert "memcontrol: Prevent scheduling while atomic in cgroup code" Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 02/15] Revert "fs: jbd2: pull your plug when waiting for space" Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 03/15] rtmutex: Fix lock stealing logic Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 04/15] posixtimer: init timer only with CONFIG_POSIX_TIMERS enabled Steven Rostedt
2017-12-01 17:35 ` Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 05/15] cpu_pm: replace raw_notifier to atomic_notifier Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 06/15] PM / CPU: replace raw_notifier with atomic_notifier (fixup) Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 07/15] kernel/hrtimer: migrate deferred timer on CPU down Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 08/15] net: take the tcp_sk_lock lock with BH disabled Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 09/15] kernel/hrtimer: dont wakeup a process while holding the hrtimer base lock Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 10/15] kernel/hrtimer/hotplug: dont wake ktimersoftd " Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 11/15] Bluetooth: avoid recursive locking in hci_send_to_channel() Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 12/15] iommu/amd: Use raw_cpu_ptr() instead of get_cpu_ptr() for ->flush_queue Steven Rostedt
2017-12-01 15:50 ` [PATCH RT 13/15] rt/locking: allow recursive local_trylock() Steven Rostedt
2017-12-01 15:50 ` Steven Rostedt [this message]
2017-12-01 15:50 ` [PATCH RT 15/15] Linux 4.9.65-rt57-rc1 Steven Rostedt
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