Waiman Long 2a8d47d551 locking/lockdep: Add debug_locks check in __lock_downgrade() ...

[ Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf ]

Tetsuo Handa had reported he saw an incorrect "downgrading a read lock"
warning right after a previous lockdep warning. It is likely that the
previous warning turned off lock debugging causing the lockdep to have
inconsistency states leading to the lock downgrade warning.

Fix that by add a check for debug_locks at the beginning of
__lock_downgrade().

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2019-10-05 12:27:39 +02:00

..

lglock.c

sched/stop_machine: Fix deadlock between multiple stop_two_cpus()

2015-06-19 10:03:12 +02:00

lockdep_internals.h

lockdep: Increase static allocations

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

lockdep_proc.c

locking/lockdep: Hide unused 'class' variable

2019-08-04 09:34:59 +02:00

lockdep_states.h

…

lockdep.c

locking/lockdep: Add debug_locks check in __lock_downgrade()

2019-10-05 12:27:39 +02:00

locktorture.c

locktorture: Fix potential memory leak with rw lock test

2017-09-13 14:09:46 -07:00

Makefile

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-09-05 20:34:28 -07:00

mcs_spinlock.h

locking/mcs: Fix mcs_spin_lock() ordering

2016-05-04 14:48:50 -07:00

mutex-debug.c

mutex: Always clear owner field upon mutex_unlock()

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

mutex-debug.h

…

mutex.c

locking/mutex: Allow next waiter lockless wakeup

2018-01-17 09:35:27 +01:00

mutex.h

locking/mutexes: Use MUTEX_SPIN_ON_OWNER when appropriate

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

osq_lock.c

locking/osq_lock: Fix osq_lock queue corruption

2018-09-19 22:48:56 +02:00

percpu-rwsem.c

locking/percpu-rwsem: Clean up the lockdep annotations in percpu_down_read()

2015-10-06 11:25:40 -07:00

qrwlock.c

locking/qrwlock: Rename ->lock to ->wait_lock

2015-09-18 09:27:29 +02:00

qspinlock_paravirt.h

locking/pvqspinlock: Kick the PV CPU unconditionally when _Q_SLOW_VAL

2015-09-18 09:27:29 +02:00

qspinlock.c

locking/qspinlock: Ensure node->count is updated before initialising node

2018-05-30 07:48:57 +02:00

rtmutex_common.h

futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()

2019-03-23 08:44:28 +01:00

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.c

futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()

2019-03-23 08:44:28 +01:00

rtmutex.h

rtmutex: Cleanup deadlock detector debug logic

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

rwsem-spinlock.c

locking/rwsem: Document barrier need when waking tasks

2015-02-18 16:57:10 +01:00

rwsem-xadd.c

locking/rwsem-xadd: Fix missed wakeup due to reordering of load

2018-09-19 22:48:56 +02:00

rwsem.c

locking/rwsem: Set lock ownership ASAP

2015-02-18 16:57:13 +01:00

rwsem.h

locking/rwsem: Set lock ownership ASAP

2015-02-18 16:57:13 +01:00

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

spinlock: Add spin_lock_bh_nested()

2015-01-03 14:32:57 -05:00