X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Flockdep.c;h=81a4e4a3f087adfc650eb6baf2c05147f209e062;hb=4b47c971dc947cadecc20dc7681037e96ece520e;hp=cb64022851c87fb900c5ef7e908bd3278f1c44ab;hpb=4b32d0a4e9ec07808a5c406a416c6576c986b047;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index cb64022851c..81a4e4a3f08 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -177,6 +177,9 @@ struct lock_class_stats lock_stats(struct lock_class *class)
 
 		lock_time_add(&pcs->read_holdtime, &stats.read_holdtime);
 		lock_time_add(&pcs->write_holdtime, &stats.write_holdtime);
+
+		for (i = 0; i < ARRAY_SIZE(stats.bounces); i++)
+			stats.bounces[i] += pcs->bounces[i];
 	}
 
 	return stats;
@@ -372,6 +375,11 @@ unsigned int max_recursion_depth;
  * about it later on, in lockdep_info().
  */
 static int lockdep_init_error;
+static unsigned long lockdep_init_trace_data[20];
+static struct stack_trace lockdep_init_trace = {
+	.max_entries = ARRAY_SIZE(lockdep_init_trace_data),
+	.entries = lockdep_init_trace_data,
+};
 
 /*
  * Various lockdep statistics:
@@ -503,11 +511,11 @@ static void lockdep_print_held_locks(struct task_struct *curr)
 	int i, depth = curr->lockdep_depth;
 
 	if (!depth) {
-		printk("no locks held by %s/%d.\n", curr->comm, curr->pid);
+		printk("no locks held by %s/%d.\n", curr->comm, task_pid_nr(curr));
 		return;
 	}
 	printk("%d lock%s held by %s/%d:\n",
-		depth, depth > 1 ? "s" : "", curr->comm, curr->pid);
+		depth, depth > 1 ? "s" : "", curr->comm, task_pid_nr(curr));
 
 	for (i = 0; i < depth; i++) {
 		printk(" #%d: ", i);
@@ -659,6 +667,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 	if (unlikely(!lockdep_initialized)) {
 		lockdep_init();
 		lockdep_init_error = 1;
+		save_stack_trace(&lockdep_init_trace);
 	}
 #endif
 
@@ -770,6 +779,10 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 	 * parallel walking of the hash-list safe:
 	 */
 	list_add_tail_rcu(&class->hash_entry, hash_head);
+	/*
+	 * Add it to the global list of classes:
+	 */
+	list_add_tail_rcu(&class->lock_entry, &all_lock_classes);
 
 	if (verbose(class)) {
 		graph_unlock();
@@ -895,7 +908,7 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth)
 	print_kernel_version();
 	printk(  "-------------------------------------------------------\n");
 	printk("%s/%d is trying to acquire lock:\n",
-		curr->comm, curr->pid);
+		curr->comm, task_pid_nr(curr));
 	print_lock(check_source);
 	printk("\nbut task is already holding lock:\n");
 	print_lock(check_target);
@@ -1076,7 +1089,7 @@ print_bad_irq_dependency(struct task_struct *curr,
 	print_kernel_version();
 	printk(  "------------------------------------------------------\n");
 	printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
-		curr->comm, curr->pid,
+		curr->comm, task_pid_nr(curr),
 		curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
 		curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
 		curr->hardirqs_enabled,
@@ -1228,7 +1241,7 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
 	print_kernel_version();
 	printk(  "---------------------------------------------\n");
 	printk("%s/%d is trying to acquire lock:\n",
-		curr->comm, curr->pid);
+		curr->comm, task_pid_nr(curr));
 	print_lock(next);
 	printk("\nbut task is already holding lock:\n");
 	print_lock(prev);
@@ -1512,7 +1525,7 @@ cache_hit:
 }
 
 static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
-	       	struct held_lock *hlock, int chain_head)
+		struct held_lock *hlock, int chain_head, u64 chain_key)
 {
 	/*
 	 * Trylock needs to maintain the stack of held locks, but it
@@ -1525,7 +1538,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
 	 * graph_lock for us)
 	 */
 	if (!hlock->trylock && (hlock->check == 2) &&
-			lookup_chain_cache(curr->curr_chain_key, hlock->class)) {
+			lookup_chain_cache(chain_key, hlock->class)) {
 		/*
 		 * Check whether last held lock:
 		 *
@@ -1567,7 +1580,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
 #else
 static inline int validate_chain(struct task_struct *curr,
 	       	struct lockdep_map *lock, struct held_lock *hlock,
-		int chain_head)
+		int chain_head, u64 chain_key)
 {
 	return 1;
 }
@@ -1632,7 +1645,7 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
 		usage_str[prev_bit], usage_str[new_bit]);
 
 	printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
-		curr->comm, curr->pid,
+		curr->comm, task_pid_nr(curr),
 		trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
 		trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
 		trace_hardirqs_enabled(curr),
@@ -1685,7 +1698,7 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
 	print_kernel_version();
 	printk(  "---------------------------------------------------------\n");
 	printk("%s/%d just changed the state of lock:\n",
-		curr->comm, curr->pid);
+		curr->comm, task_pid_nr(curr));
 	print_lock(this);
 	if (forwards)
 		printk("but this lock took another, %s-irq-unsafe lock in the past:\n", irqclass);
@@ -2273,10 +2286,6 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
 			return 0;
 		break;
 	case LOCK_USED:
-		/*
-		 * Add it to the global list of classes:
-		 */
-		list_add_tail_rcu(&this->class->lock_entry, &all_lock_classes);
 		debug_atomic_dec(&nr_unused_locks);
 		break;
 	default:
@@ -2325,6 +2334,9 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
 	lock->name = name;
 	lock->key = key;
 	lock->class_cache = NULL;
+#ifdef CONFIG_LOCK_STAT
+	lock->cpu = raw_smp_processor_id();
+#endif
 	if (subclass)
 		register_lock_class(lock, subclass, 1);
 }
@@ -2412,7 +2424,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 		return 0;
 
 	/*
-	 * Calculate the chain hash: it's the combined has of all the
+	 * Calculate the chain hash: it's the combined hash of all the
 	 * lock keys along the dependency chain. We save the hash value
 	 * at every step so that we can get the current hash easily
 	 * after unlock. The chain hash is then used to cache dependency
@@ -2438,11 +2450,11 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 		chain_head = 1;
 	}
 	chain_key = iterate_chain_key(chain_key, id);
-	curr->curr_chain_key = chain_key;
 
-	if (!validate_chain(curr, lock, hlock, chain_head))
+	if (!validate_chain(curr, lock, hlock, chain_head, chain_key))
 		return 0;
 
+	curr->curr_chain_key = chain_key;
 	curr->lockdep_depth++;
 	check_chain_key(curr);
 #ifdef CONFIG_DEBUG_LOCKDEP
@@ -2475,7 +2487,7 @@ print_unlock_inbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
 	printk(  "[ BUG: bad unlock balance detected! ]\n");
 	printk(  "-------------------------------------\n");
 	printk("%s/%d is trying to release lock (",
-		curr->comm, curr->pid);
+		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
 	printk(") at:\n");
 	print_ip_sym(ip);
@@ -2642,10 +2654,15 @@ static void check_flags(unsigned long flags)
 	if (!debug_locks)
 		return;
 
-	if (irqs_disabled_flags(flags))
-		DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled);
-	else
-		DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled);
+	if (irqs_disabled_flags(flags)) {
+		if (DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)) {
+			printk("possible reason: unannotated irqs-off.\n");
+		}
+	} else {
+		if (DEBUG_LOCKS_WARN_ON(!current->hardirqs_enabled)) {
+			printk("possible reason: unannotated irqs-on.\n");
+		}
+	}
 
 	/*
 	 * We dont accurately track softirq state in e.g.
@@ -2725,7 +2742,7 @@ print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
 	printk(  "[ BUG: bad contention detected! ]\n");
 	printk(  "---------------------------------\n");
 	printk("%s/%d is trying to contend lock (",
-		curr->comm, curr->pid);
+		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
 	printk(") at:\n");
 	print_ip_sym(ip);
@@ -2775,6 +2792,8 @@ found_it:
 	stats = get_lock_stats(hlock->class);
 	if (point < ARRAY_SIZE(stats->contention_point))
 		stats->contention_point[i]++;
+	if (lock->cpu != smp_processor_id())
+		stats->bounces[bounce_contended + !!hlock->read]++;
 	put_lock_stats(stats);
 }
 
@@ -2786,8 +2805,8 @@ __lock_acquired(struct lockdep_map *lock)
 	struct lock_class_stats *stats;
 	unsigned int depth;
 	u64 now;
-	s64 waittime;
-	int i;
+	s64 waittime = 0;
+	int i, cpu;
 
 	depth = curr->lockdep_depth;
 	if (DEBUG_LOCKS_WARN_ON(!depth))
@@ -2809,19 +2828,25 @@ __lock_acquired(struct lockdep_map *lock)
 	return;
 
 found_it:
-	if (!hlock->waittime_stamp)
-		return;
-
-	now = sched_clock();
-	waittime = now - hlock->waittime_stamp;
-	hlock->holdtime_stamp = now;
+	cpu = smp_processor_id();
+	if (hlock->waittime_stamp) {
+		now = sched_clock();
+		waittime = now - hlock->waittime_stamp;
+		hlock->holdtime_stamp = now;
+	}
 
 	stats = get_lock_stats(hlock->class);
-	if (hlock->read)
-		lock_time_inc(&stats->read_waittime, waittime);
-	else
-		lock_time_inc(&stats->write_waittime, waittime);
+	if (waittime) {
+		if (hlock->read)
+			lock_time_inc(&stats->read_waittime, waittime);
+		else
+			lock_time_inc(&stats->write_waittime, waittime);
+	}
+	if (lock->cpu != cpu)
+		stats->bounces[bounce_acquired + !!hlock->read]++;
 	put_lock_stats(stats);
+
+	lock->cpu = cpu;
 }
 
 void lock_contended(struct lockdep_map *lock, unsigned long ip)
@@ -2907,7 +2932,7 @@ static void zap_class(struct lock_class *class)
 
 }
 
-static inline int within(void *addr, void *start, unsigned long size)
+static inline int within(const void *addr, void *start, unsigned long size)
 {
 	return addr >= start && addr < start + size;
 }
@@ -2918,9 +2943,10 @@ void lockdep_free_key_range(void *start, unsigned long size)
 	struct list_head *head;
 	unsigned long flags;
 	int i;
+	int locked;
 
 	raw_local_irq_save(flags);
-	graph_lock();
+	locked = graph_lock();
 
 	/*
 	 * Unhash all classes that were created by this module:
@@ -2929,12 +2955,16 @@ void lockdep_free_key_range(void *start, unsigned long size)
 		head = classhash_table + i;
 		if (list_empty(head))
 			continue;
-		list_for_each_entry_safe(class, next, head, hash_entry)
+		list_for_each_entry_safe(class, next, head, hash_entry) {
 			if (within(class->key, start, size))
 				zap_class(class);
+			else if (within(class->name, start, size))
+				zap_class(class);
+		}
 	}
 
-	graph_unlock();
+	if (locked)
+		graph_unlock();
 	raw_local_irq_restore(flags);
 }
 
@@ -2944,6 +2974,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
 	struct list_head *head;
 	unsigned long flags;
 	int i, j;
+	int locked;
 
 	raw_local_irq_save(flags);
 
@@ -2962,7 +2993,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
 	 * Debug check: in the end all mapped classes should
 	 * be gone.
 	 */
-	graph_lock();
+	locked = graph_lock();
 	for (i = 0; i < CLASSHASH_SIZE; i++) {
 		head = classhash_table + i;
 		if (list_empty(head))
@@ -2975,7 +3006,8 @@ void lockdep_reset_lock(struct lockdep_map *lock)
 			}
 		}
 	}
-	graph_unlock();
+	if (locked)
+		graph_unlock();
 
 out_restore:
 	raw_local_irq_restore(flags);
@@ -3026,16 +3058,14 @@ void __init lockdep_info(void)
 		sizeof(struct held_lock) * MAX_LOCK_DEPTH);
 
 #ifdef CONFIG_DEBUG_LOCKDEP
-	if (lockdep_init_error)
-		printk("WARNING: lockdep init error! Arch code didnt call lockdep_init() early enough?\n");
+	if (lockdep_init_error) {
+		printk("WARNING: lockdep init error! Arch code didn't call lockdep_init() early enough?\n");
+		printk("Call stack leading to lockdep invocation was:\n");
+		print_stack_trace(&lockdep_init_trace, 0);
+	}
 #endif
 }
 
-static inline int in_range(const void *start, const void *addr, const void *end)
-{
-	return addr >= start && addr <= end;
-}
-
 static void
 print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
 		     const void *mem_to, struct held_lock *hlock)
@@ -3049,7 +3079,7 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
 	printk(  "[ BUG: held lock freed! ]\n");
 	printk(  "-------------------------\n");
 	printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",
-		curr->comm, curr->pid, mem_from, mem_to-1);
+		curr->comm, task_pid_nr(curr), mem_from, mem_to-1);
 	print_lock(hlock);
 	lockdep_print_held_locks(curr);
 
@@ -3057,6 +3087,13 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
 	dump_stack();
 }
 
+static inline int not_in_range(const void* mem_from, unsigned long mem_len,
+				const void* lock_from, unsigned long lock_len)
+{
+	return lock_from + lock_len <= mem_from ||
+		mem_from + mem_len <= lock_from;
+}
+
 /*
  * Called when kernel memory is freed (or unmapped), or if a lock
  * is destroyed or reinitialized - this code checks whether there is
@@ -3064,7 +3101,6 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
  */
 void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
 {
-	const void *mem_to = mem_from + mem_len, *lock_from, *lock_to;
 	struct task_struct *curr = current;
 	struct held_lock *hlock;
 	unsigned long flags;
@@ -3077,14 +3113,11 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
 	for (i = 0; i < curr->lockdep_depth; i++) {
 		hlock = curr->held_locks + i;
 
-		lock_from = (void *)hlock->instance;
-		lock_to = (void *)(hlock->instance + 1);
-
-		if (!in_range(mem_from, lock_from, mem_to) &&
-					!in_range(mem_from, lock_to, mem_to))
+		if (not_in_range(mem_from, mem_len, hlock->instance,
+					sizeof(*hlock->instance)))
 			continue;
 
-		print_freed_lock_bug(curr, mem_from, mem_to, hlock);
+		print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
 		break;
 	}
 	local_irq_restore(flags);
@@ -3102,7 +3135,7 @@ static void print_held_locks_bug(struct task_struct *curr)
 	printk(  "[ BUG: lock held at task exit time! ]\n");
 	printk(  "-------------------------------------\n");
 	printk("%s/%d is exiting with locks still held!\n",
-		curr->comm, curr->pid);
+		curr->comm, task_pid_nr(curr));
 	lockdep_print_held_locks(curr);
 
 	printk("\nstack backtrace:\n");
@@ -3150,6 +3183,13 @@ retry:
 		printk(" locked it.\n");
 
 	do_each_thread(g, p) {
+		/*
+		 * It's not reliable to print a task's held locks
+		 * if it's not sleeping (or if it's not the current
+		 * task):
+		 */
+		if (p->state == TASK_RUNNING && p != current)
+			continue;
 		if (p->lockdep_depth)
 			lockdep_print_held_locks(p);
 		if (!unlock)
@@ -3166,7 +3206,11 @@ retry:
 
 EXPORT_SYMBOL_GPL(debug_show_all_locks);
 
-void debug_show_held_locks(struct task_struct *task)
+/*
+ * Careful: only use this function if you are sure that
+ * the task cannot run in parallel!
+ */
+void __debug_show_held_locks(struct task_struct *task)
 {
 	if (unlikely(!debug_locks)) {
 		printk("INFO: lockdep is turned off.\n");
@@ -3174,5 +3218,27 @@ void debug_show_held_locks(struct task_struct *task)
 	}
 	lockdep_print_held_locks(task);
 }
+EXPORT_SYMBOL_GPL(__debug_show_held_locks);
+
+void debug_show_held_locks(struct task_struct *task)
+{
+		__debug_show_held_locks(task);
+}
 
 EXPORT_SYMBOL_GPL(debug_show_held_locks);
+
+void lockdep_sys_exit(void)
+{
+	struct task_struct *curr = current;
+
+	if (unlikely(curr->lockdep_depth)) {
+		if (!debug_locks_off())
+			return;
+		printk("\n================================================\n");
+		printk(  "[ BUG: lock held when returning to user space! ]\n");
+		printk(  "------------------------------------------------\n");
+		printk("%s/%d is leaving the kernel with locks still held!\n",
+				curr->comm, curr->pid);
+		lockdep_print_held_locks(curr);
+	}
+}