Sebastian Andrzej Siewior 6221586c98 locking/rtmutex: Avoid a NULL pointer dereference on deadlock ...

commit 8d1e5a1a1ccf5ae9d8a5a0ee7960202ccb0c5429 upstream.

With task_blocks_on_rt_mutex() returning early -EDEADLK we never
add the waiter to the waitqueue. Later, we try to remove it via
remove_waiter() and go boom in rt_mutex_top_waiter() because
rb_entry() gives a NULL pointer.

( Tested on v3.18-RT where rtmutex is used for regular mutex and I
  tried to get one twice in a row. )

Not sure when this started but I guess 397335f004f4 ("rtmutex: Fix
deadlock detector for real") or commit 3d5c9340d194 ("rtmutex:
Handle deadlock detection smarter").

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1424187823-19600-1-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2015-03-18 14:11:05 +01:00

..

lglock.c

locking: Move the lglocks code to kernel/locking/

2013-11-06 09:24:20 +01:00

lockdep_internals.h

lockdep: Increase static allocations

2014-04-18 14:20:50 +02:00

lockdep_proc.c

lockdep/proc: Fix lock-time avg computation

2013-11-11 12:41:34 +01:00

lockdep_states.h

locking: Move the lockdep code to kernel/locking/

2013-11-06 07:55:08 +01:00

lockdep.c

locking/lockdep: Revert qrwlock recusive stuff

2014-10-03 06:09:30 +02:00

locktorture.c

locktorture: Cleanup header usage

2014-09-30 00:10:02 -07:00

Makefile

locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks

2014-06-06 07:58:28 +02:00

mcs_spinlock.c

arch, locking: Ciao arch_mutex_cpu_relax()

2014-07-17 12:32:47 +02:00

mcs_spinlock.h

locking/mcs: Remove obsolete comment

2014-08-13 10:32:00 +02:00

mutex-debug.c

mutex: Always clear owner field upon mutex_unlock()

2015-01-09 11:20:39 +01:00

mutex-debug.h

locking: Move the mutex code to kernel/locking/

2013-11-06 07:55:07 +01:00

mutex.c

locking/mutex: Don't assume TASK_RUNNING

2014-10-28 10:55:08 +01:00

mutex.h

locking/mutexes: Use MUTEX_SPIN_ON_OWNER when appropriate

2014-08-13 10:32:02 +02:00

percpu-rwsem.c

locking: Move the percpu-rwsem code to kernel/locking/

2013-11-06 09:24:22 +01:00

qrwlock.c

arch, locking: Ciao arch_mutex_cpu_relax()

2014-07-17 12:32:47 +02:00

rtmutex_common.h

rtmutex: Cleanup deadlock detector debug logic

2014-06-21 22:05:30 +02:00

rtmutex-debug.c

rtmutex: Cleanup deadlock detector debug logic

2014-06-21 22:05:30 +02:00

rtmutex-debug.h

rtmutex: Cleanup deadlock detector debug logic

2014-06-21 22:05:30 +02:00

rtmutex-tester.c

locking: Move the rtmutex code to kernel/locking/

2013-11-06 09:23:59 +01:00

rtmutex.c

locking/rtmutex: Avoid a NULL pointer dereference on deadlock

2015-03-18 14:11:05 +01:00

rtmutex.h

rtmutex: Cleanup deadlock detector debug logic

2014-06-21 22:05:30 +02:00

rwsem-spinlock.c

locking/rwsem: Rename 'activity' to 'count'

2014-07-16 14:56:55 +02:00

rwsem-xadd.c

locking/rwsem: Avoid double checking before try acquiring write lock

2014-10-03 06:09:29 +02:00

rwsem.c

locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER

2014-07-16 14:57:13 +02:00

semaphore.c

locking/semaphore: Resolve some shadow warnings

2014-09-04 07:17:24 +02:00

spinlock_debug.c

locking: Move the spinlock code to kernel/locking/

2013-11-06 07:55:21 +01:00

spinlock.c

locking: Move the spinlock code to kernel/locking/

2013-11-06 07:55:21 +01:00