Waiman Long 9423770eb3 locking/lockdep: Add debug_locks check in __lock_downgrade() ...

[ Upstream commit 71492580571467fb7177aade19c18ce7486267f5 ]

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().

Debugged-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2019-10-01 08:26:07 +02:00

..

lockdep_internals.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

lockdep_proc.c

locking/lockdep: Hide unused 'class' variable

2019-07-31 07:27:09 +02:00

lockdep_states.h

…

lockdep.c

locking/lockdep: Add debug_locks check in __lock_downgrade()

2019-10-01 08:26:07 +02:00

locktorture.c

Merge tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drm

2018-08-15 17:39:07 -07:00

Makefile

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

mcs_spinlock.h

locking/mcs: Use smp_cond_load_acquire() in MCS spin loop

2018-04-27 09:48:49 +02:00

mutex-debug.c

…

mutex-debug.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

mutex.c

locking/mutex: Fix mutex debug call and ww_mutex documentation

2018-09-10 10:05:10 +02:00

mutex.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

osq_lock.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

percpu-rwsem.c

…

qrwlock.c

…

qspinlock_paravirt.h

locking/qspinlock: Remove duplicate clear_pending() function from PV code

2018-04-27 12:55:22 +02:00

qspinlock_stat.h

locking/qspinlock: Add stat tracking for pending vs. slowpath

2018-04-27 09:48:53 +02:00

qspinlock.c

locking/qspinlock, x86: Provide liveness guarantee

2018-12-21 14:15:12 +01:00

rtmutex_common.h

locking/rtmutex: Handle non enqueued waiters gracefully in remove_waiter()

2018-03-28 23:01:30 +02:00

rtmutex-debug.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

rtmutex-debug.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

rtmutex.c

futex: Handle early deadlock return correctly

2019-02-12 19:47:24 +01:00

rtmutex.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

rwsem-spinlock.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

rwsem-xadd.c

locking/rwsem: Prevent decrement of reader count before increment

2019-05-22 07:37:34 +02:00

rwsem.c

locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS

2018-06-20 11:29:23 +02:00

rwsem.h

locking/rwsem: Add a new RWSEM_ANONYMOUSLY_OWNED flag

2018-05-16 11:45:15 +02:00

semaphore.c

…

spinlock_debug.c

…

spinlock.c

locking/core: Remove break_lock field when CONFIG_GENERIC_LOCKBREAK=y

2017-12-12 11:24:01 +01:00

test-ww_mutex.c

locking/ww_mutex: Fix runtime warning in the WW mutex selftest

2018-10-03 08:56:31 +02:00