lockdep: spin_lock_nest_lock()

Expose the new lock protection lock.

This can be used to annotate places where we take multiple locks of the
same class and avoid deadlocks by always taking another (top-level) lock
first.

NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index 8a2307ce7296..d79845d034b5 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -22,6 +22,8 @@ int in_lock_functions(unsigned long addr);
 void __lockfunc _spin_lock(spinlock_t *lock)		__acquires(lock);
 void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
 							__acquires(lock);
+void __lockfunc _spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *map)
+							__acquires(lock);
 void __lockfunc _read_lock(rwlock_t *lock)		__acquires(lock);
 void __lockfunc _write_lock(rwlock_t *lock)		__acquires(lock);
 void __lockfunc _spin_lock_bh(spinlock_t *lock)		__acquires(lock);