Commit b7d39aff authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

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: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7531e2f3
No related merge requests found
......@@ -410,8 +410,10 @@ static inline void print_irqtrace_events(struct task_struct *curr)
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i)
# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i)
# else
# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i)
# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, NULL, i)
# endif
# define spin_release(l, n, i) lock_release(l, n, i)
#else
......
......@@ -183,8 +183,14 @@ do { \
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
# define spin_lock_nest_lock(lock, nest_lock) \
do { \
typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
} while (0)
#else
# define spin_lock_nested(lock, subclass) _spin_lock(lock)
# define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
#endif
#define write_lock(lock) _write_lock(lock)
......
......@@ -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);
......
......@@ -292,6 +292,7 @@ void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
}
EXPORT_SYMBOL(_spin_lock_nested);
unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
{
unsigned long flags;
......@@ -314,6 +315,16 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclas
EXPORT_SYMBOL(_spin_lock_irqsave_nested);
void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
struct lockdep_map *nest_lock)
{
preempt_disable();
spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nest_lock);
#endif
void __lockfunc _spin_unlock(spinlock_t *lock)
......
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