linux/kernel/locking
Peter Zijlstra 35a9393c95 lockdep: Fix the module unload key range freeing logic
Module unload calls lockdep_free_key_range(), which removes entries
from the data structures. Most of the lockdep code OTOH assumes the
data structures are append only; in specific see the comments in
add_lock_to_list() and look_up_lock_class().

Clearly this has only worked by accident; make it work proper. The
actual scenario to make it go boom would involve the memory freed by
the module unlock being re-allocated and re-used for a lock inside of
a rcu-sched grace period. This is a very unlikely scenario, still
better plug the hole.

Use RCU list iteration in all places and ammend the comments.

Change lockdep_free_key_range() to issue a sync_sched() between
removal from the lists and returning -- which results in the memory
being freed. Further ensure the callers are placed correctly and
comment the requirements.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Tsyvarev <tsyvarev@ispras.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 10:49:07 +01:00
..
lglock.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c lockdep: Fix the module unload key range freeing logic 2015-03-23 10:49:07 +01:00
locktorture.c locktorture: Cleanup header usage 2014-09-30 00:10:02 -07:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2015-02-11 17:42:32 -08:00
mcs_spinlock.h locking/mcs: Better differentiate between MCS variants 2015-01-14 15:07:32 +01:00
mutex-debug.c mutex: Always clear owner field upon mutex_unlock() 2015-01-09 11:20:39 +01:00
mutex-debug.h
mutex.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-09 16:06:06 -08:00
mutex.h locking/mutexes: Use MUTEX_SPIN_ON_OWNER when appropriate 2014-08-13 10:32:02 +02:00
osq_lock.c locking/osq: No need for load/acquire when acquire-polling 2015-01-14 15:16:20 +01:00
percpu-rwsem.c
qrwlock.c arch, locking: Ciao arch_mutex_cpu_relax() 2014-07-17 12:32:47 +02:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c locking/rtmutex: Set state back to running on error 2015-03-01 09:45:06 +01:00
rtmutex.h
rwsem-spinlock.c locking/rwsem: Use task->state helpers 2015-02-04 07:57:39 +01:00
rwsem-xadd.c locking/rwsem: Use task->state helpers 2015-02-04 07:57:39 +01:00
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
spinlock.c spinlock: Add spin_lock_bh_nested() 2015-01-03 14:32:57 -05:00