lockdep: various fixes

 - update the copyright notices
 - use the default hash function
 - fix a thinko in a BUILD_BUG_ON
 - add a WARN_ON to spot inconsitent naming
 - fix a termination issue in /proc/lock_stat

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 19 insertions, 11 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 8f946f614f8e..3d3386b88b6a 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -1,7 +1,8 @@
 /*
  * Runtime locking correctness validator
  *
- *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  * see Documentation/lockdep-design.txt for more details.
  */
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index a8dc99d9fef7..cb64022851c8 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -5,7 +5,8 @@
  *
  * Started by Ingo Molnar:
  *
- *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  * this code maps all the lock dependencies as they occur in a live kernel
  * and will warn about the following classes of locking bugs:
@@ -37,6 +38,7 @@
 #include <linux/debug_locks.h>
 #include <linux/irqflags.h>
 #include <linux/utsname.h>
+#include <linux/hash.h>
 
 #include <asm/sections.h>
 
@@ -238,8 +240,7 @@ LIST_HEAD(all_lock_classes);
  */
 #define CLASSHASH_BITS		(MAX_LOCKDEP_KEYS_BITS - 1)
 #define CLASSHASH_SIZE		(1UL << CLASSHASH_BITS)
-#define CLASSHASH_MASK		(CLASSHASH_SIZE - 1)
-#define __classhashfn(key)	((((unsigned long)key >> CLASSHASH_BITS) + (unsigned long)key) & CLASSHASH_MASK)
+#define __classhashfn(key)	hash_long((unsigned long)key, CLASSHASH_BITS)
 #define classhashentry(key)	(classhash_table + __classhashfn((key)))
 
 static struct list_head classhash_table[CLASSHASH_SIZE];
@@ -250,9 +251,7 @@ static struct list_head classhash_table[CLASSHASH_SIZE];
  */
 #define CHAINHASH_BITS		(MAX_LOCKDEP_CHAINS_BITS-1)
 #define CHAINHASH_SIZE		(1UL << CHAINHASH_BITS)
-#define CHAINHASH_MASK		(CHAINHASH_SIZE - 1)
-#define __chainhashfn(chain) \
-		(((chain >> CHAINHASH_BITS) + chain) & CHAINHASH_MASK)
+#define __chainhashfn(chain)	hash_long(chain, CHAINHASH_BITS)
 #define chainhashentry(chain)	(chainhash_table + __chainhashfn((chain)))
 
 static struct list_head chainhash_table[CHAINHASH_SIZE];
@@ -676,7 +675,8 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 	 * (or spin_lock_init()) call - which acts as the key. For static
 	 * locks we use the lock object itself as the key.
 	 */
-	BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(struct lock_class));
+	BUILD_BUG_ON(sizeof(struct lock_class_key) >
+			sizeof(struct lockdep_map));
 
 	key = lock->key->subkeys + subclass;
 
@@ -686,9 +686,12 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 	 * We can walk the hash lockfree, because the hash only
 	 * grows, and we are careful when adding entries to the end:
 	 */
-	list_for_each_entry(class, hash_head, hash_entry)
-		if (class->key == key)
+	list_for_each_entry(class, hash_head, hash_entry) {
+		if (class->key == key) {
+			WARN_ON_ONCE(class->name != lock->name);
 			return class;
+		}
+	}
 
 	return NULL;
 }
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index e682926c9ad6..39163ed1bf0a 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -5,7 +5,8 @@
  *
  * Started by Ingo Molnar:
  *
- *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  * Code for /proc/lockdep and /proc/lockdep_stats:
  *
@@ -498,6 +499,9 @@ static void *ls_start(struct seq_file *m, loff_t *pos)
 	if (data->iter == data->stats)
 		seq_header(m);
 
+	if (data->iter == data->iter_end)
+		data->iter = NULL;
+
 	return data->iter;
 }