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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-07-20 19:16:29 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-02 15:41:34 +0200 |
| commit | f607c6685774811b8112e124f10a053d77015485 (patch) | |
| tree | 4d32d967c8f8fb37ae09319735062a131a91725b | |
| parent | 98c33eddaf41d225d99b40f9eedbd0fac4c08c05 (diff) | |
| download | linux-f607c6685774811b8112e124f10a053d77015485.tar.bz2 | |
lockdep: Introduce lockdep_assert_held()
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>
| -rw-r--r-- | include/linux/lockdep.h | 8 | ||||
| -rw-r--r-- | kernel/lockdep.c | 33 | ||||
| -rw-r--r-- | kernel/sched.c | 2 |
3 files changed, 43 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 12aabfcb45f6..a6d5e5e4d084 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -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, 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, struct lock_class_key *key, unsigned int subclass, 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_assert_held(l) WARN_ON(debug_locks && !lockdep_is_held(l)) + #else /* !LOCKDEP */ static inline void lockdep_off(void) @@ -358,6 +364,8 @@ struct lock_class_key { }; #define lockdep_depth(tsk) (0) +#define lockdep_assert_held(l) do { } while (0) + #endif /* !LOCKDEP */ #ifdef CONFIG_LOCK_STAT diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 4b6cebe8ab31..28914a509914 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3059,6 +3059,19 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip) 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: */ @@ -3160,6 +3173,26 @@ void lock_release(struct lockdep_map *lock, int nested, } 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) { current->lockdep_reclaim_gfp = gfp_mask; diff --git a/kernel/sched.c b/kernel/sched.c index 1b59e265273b..2c75f7daa439 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6609,6 +6609,8 @@ int cond_resched_lock(spinlock_t *lock) int resched = should_resched(); int ret = 0; + lockdep_assert_held(lock); + if (spin_needbreak(lock) || resched) { spin_unlock(lock); if (resched) |