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lockdep: Introduce lockdep_assert_held()

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Add a lockdep helper to validate that we indeed are the owner
of a lock.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2009-07-20 19:16:29 +02:00
committed by Ingo Molnar
parent 98c33eddaf
commit f607c66857
3 changed files with 43 additions and 0 deletions
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8
include/linux/lockdep.h
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@@ -296,6 +296,10 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
extern void lock_release(struct lockdep_map *lock, int nested, extern void lock_release(struct lockdep_map *lock, int nested,
unsigned long ip); unsigned long ip);
#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map)
extern int lock_is_held(struct lockdep_map *lock);
extern void lock_set_class(struct lockdep_map *lock, const char *name, extern void lock_set_class(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, unsigned int subclass, struct lock_class_key *key, unsigned int subclass,
unsigned long ip); unsigned long ip);
@@ -314,6 +318,8 @@ extern void lockdep_trace_alloc(gfp_t mask);
#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
#define lockdep_assert_held(l) WARN_ON(debug_locks && !lockdep_is_held(l))
#else /* !LOCKDEP */ #else /* !LOCKDEP */
static inline void lockdep_off(void) static inline void lockdep_off(void)
@@ -358,6 +364,8 @@ struct lock_class_key { };
#define lockdep_depth(tsk) (0) #define lockdep_depth(tsk) (0)
#define lockdep_assert_held(l) do { } while (0)
#endif /* !LOCKDEP */ #endif /* !LOCKDEP */
#ifdef CONFIG_LOCK_STAT #ifdef CONFIG_LOCK_STAT

33
kernel/lockdep.c
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@@ -3059,6 +3059,19 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
check_chain_key(curr); check_chain_key(curr);
} }
static int __lock_is_held(struct lockdep_map *lock)
{
struct task_struct *curr = current;
int i;
for (i = 0; i < curr->lockdep_depth; i++) {
if (curr->held_locks[i].instance == lock)
return 1;
}
return 0;
}
/* /*
* Check whether we follow the irq-flags state precisely: * Check whether we follow the irq-flags state precisely:
*/ */
@@ -3160,6 +3173,26 @@ void lock_release(struct lockdep_map *lock, int nested,
} }
EXPORT_SYMBOL_GPL(lock_release); EXPORT_SYMBOL_GPL(lock_release);
int lock_is_held(struct lockdep_map *lock)
{
unsigned long flags;
int ret = 0;
if (unlikely(current->lockdep_recursion))
return ret;
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
ret = __lock_is_held(lock);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
return ret;
}
EXPORT_SYMBOL_GPL(lock_is_held);
void lockdep_set_current_reclaim_state(gfp_t gfp_mask) void lockdep_set_current_reclaim_state(gfp_t gfp_mask)
{ {
current->lockdep_reclaim_gfp = gfp_mask; current->lockdep_reclaim_gfp = gfp_mask;

2
kernel/sched.c
View File

@@ -6609,6 +6609,8 @@ int cond_resched_lock(spinlock_t *lock)
int resched = should_resched(); int resched = should_resched();
int ret = 0; int ret = 0;
lockdep_assert_held(lock);
if (spin_needbreak(lock) || resched) { if (spin_needbreak(lock) || resched) {
spin_unlock(lock); spin_unlock(lock);
if (resched) if (resched)