[PATCH] lockdep: better lock debugging

Generic lock debugging:

 - generalized lock debugging framework. For example, a bug in one lock
   subsystem turns off debugging in all lock subsystems.

 - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
   the mutex/rtmutex debugging code: it caused way too much prototype
   hackery, and lockdep will give the same information anyway.

 - ability to do silent tests

 - check lock freeing in vfree too.

 - more finegrained debugging options, to allow distributions to
   turn off more expensive debugging features.

There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes.  (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)

Here are the current debugging options:

CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y

which do:

 config DEBUG_MUTEXES
          bool "Mutex debugging, basic checks"

 config DEBUG_LOCK_ALLOC
         bool "Detect incorrect freeing of live mutexes"

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 22 insertions, 24 deletions

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 45d61016da57..91b699aa658b 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -161,8 +161,7 @@ static int rt_mutex_adjust_prio_chain(task_t *task,
 				      int deadlock_detect,
 				      struct rt_mutex *orig_lock,
 				      struct rt_mutex_waiter *orig_waiter,
-				      struct task_struct *top_task
-				      __IP_DECL__)
+				      struct task_struct *top_task)
 {
 	struct rt_mutex *lock;
 	struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
@@ -357,7 +356,7 @@ static inline int try_to_steal_lock(struct rt_mutex *lock)
  *
  * Must be called with lock->wait_lock held.
  */
-static int try_to_take_rt_mutex(struct rt_mutex *lock __IP_DECL__)
+static int try_to_take_rt_mutex(struct rt_mutex *lock)
 {
 	/*
 	 * We have to be careful here if the atomic speedups are
@@ -384,7 +383,7 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock __IP_DECL__)
 		return 0;
 
 	/* We got the lock. */
-	debug_rt_mutex_lock(lock __IP__);
+	debug_rt_mutex_lock(lock);
 
 	rt_mutex_set_owner(lock, current, 0);
 
@@ -402,8 +401,7 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock __IP_DECL__)
  */
 static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
 				   struct rt_mutex_waiter *waiter,
-				   int detect_deadlock
-				   __IP_DECL__)
+				   int detect_deadlock)
 {
 	struct rt_mutex_waiter *top_waiter = waiter;
 	task_t *owner = rt_mutex_owner(lock);
@@ -454,7 +452,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
 	spin_unlock(&lock->wait_lock);
 
 	res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
-					 current __IP__);
+					 current);
 
 	spin_lock(&lock->wait_lock);
 
@@ -526,7 +524,7 @@ static void wakeup_next_waiter(struct rt_mutex *lock)
  * Must be called with lock->wait_lock held
  */
 static void remove_waiter(struct rt_mutex *lock,
-			  struct rt_mutex_waiter *waiter  __IP_DECL__)
+			  struct rt_mutex_waiter *waiter)
 {
 	int first = (waiter == rt_mutex_top_waiter(lock));
 	int boost = 0;
@@ -568,7 +566,7 @@ static void remove_waiter(struct rt_mutex *lock,
 
 	spin_unlock(&lock->wait_lock);
 
-	rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current __IP__);
+	rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);
 
 	spin_lock(&lock->wait_lock);
 }
@@ -595,7 +593,7 @@ void rt_mutex_adjust_pi(struct task_struct *task)
 	get_task_struct(task);
 	spin_unlock_irqrestore(&task->pi_lock, flags);
 
-	rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task __RET_IP__);
+	rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
 }
 
 /*
@@ -604,7 +602,7 @@ void rt_mutex_adjust_pi(struct task_struct *task)
 static int __sched
 rt_mutex_slowlock(struct rt_mutex *lock, int state,
 		  struct hrtimer_sleeper *timeout,
-		  int detect_deadlock __IP_DECL__)
+		  int detect_deadlock)
 {
 	struct rt_mutex_waiter waiter;
 	int ret = 0;
@@ -615,7 +613,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 	spin_lock(&lock->wait_lock);
 
 	/* Try to acquire the lock again: */
-	if (try_to_take_rt_mutex(lock __IP__)) {
+	if (try_to_take_rt_mutex(lock)) {
 		spin_unlock(&lock->wait_lock);
 		return 0;
 	}
@@ -629,7 +627,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 
 	for (;;) {
 		/* Try to acquire the lock: */
-		if (try_to_take_rt_mutex(lock __IP__))
+		if (try_to_take_rt_mutex(lock))
 			break;
 
 		/*
@@ -653,7 +651,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 		 */
 		if (!waiter.task) {
 			ret = task_blocks_on_rt_mutex(lock, &waiter,
-						      detect_deadlock __IP__);
+						      detect_deadlock);
 			/*
 			 * If we got woken up by the owner then start loop
 			 * all over without going into schedule to try
@@ -680,7 +678,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 	set_current_state(TASK_RUNNING);
 
 	if (unlikely(waiter.task))
-		remove_waiter(lock, &waiter __IP__);
+		remove_waiter(lock, &waiter);
 
 	/*
 	 * try_to_take_rt_mutex() sets the waiter bit
@@ -711,7 +709,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
  * Slow path try-lock function:
  */
 static inline int
-rt_mutex_slowtrylock(struct rt_mutex *lock __IP_DECL__)
+rt_mutex_slowtrylock(struct rt_mutex *lock)
 {
 	int ret = 0;
 
@@ -719,7 +717,7 @@ rt_mutex_slowtrylock(struct rt_mutex *lock __IP_DECL__)
 
 	if (likely(rt_mutex_owner(lock) != current)) {
 
-		ret = try_to_take_rt_mutex(lock __IP__);
+		ret = try_to_take_rt_mutex(lock);
 		/*
 		 * try_to_take_rt_mutex() sets the lock waiters
 		 * bit unconditionally. Clean this up.
@@ -769,13 +767,13 @@ rt_mutex_fastlock(struct rt_mutex *lock, int state,
 		  int detect_deadlock,
 		  int (*slowfn)(struct rt_mutex *lock, int state,
 				struct hrtimer_sleeper *timeout,
-				int detect_deadlock __IP_DECL__))
+				int detect_deadlock))
 {
 	if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
 		rt_mutex_deadlock_account_lock(lock, current);
 		return 0;
 	} else
-		return slowfn(lock, state, NULL, detect_deadlock __RET_IP__);
+		return slowfn(lock, state, NULL, detect_deadlock);
 }
 
 static inline int
@@ -783,24 +781,24 @@ rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
 			struct hrtimer_sleeper *timeout, int detect_deadlock,
 			int (*slowfn)(struct rt_mutex *lock, int state,
 				      struct hrtimer_sleeper *timeout,
-				      int detect_deadlock __IP_DECL__))
+				      int detect_deadlock))
 {
 	if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
 		rt_mutex_deadlock_account_lock(lock, current);
 		return 0;
 	} else
-		return slowfn(lock, state, timeout, detect_deadlock __RET_IP__);
+		return slowfn(lock, state, timeout, detect_deadlock);
 }
 
 static inline int
 rt_mutex_fasttrylock(struct rt_mutex *lock,
-		     int (*slowfn)(struct rt_mutex *lock __IP_DECL__))
+		     int (*slowfn)(struct rt_mutex *lock))
 {
 	if (likely(rt_mutex_cmpxchg(lock, NULL, current))) {
 		rt_mutex_deadlock_account_lock(lock, current);
 		return 1;
 	}
-	return slowfn(lock __RET_IP__);
+	return slowfn(lock);
 }
 
 static inline void
@@ -948,7 +946,7 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
 				struct task_struct *proxy_owner)
 {
 	__rt_mutex_init(lock, NULL);
-	debug_rt_mutex_proxy_lock(lock, proxy_owner __RET_IP__);
+	debug_rt_mutex_proxy_lock(lock, proxy_owner);
 	rt_mutex_set_owner(lock, proxy_owner, 0);
 	rt_mutex_deadlock_account_lock(lock, proxy_owner);
 }