[PATCH] mutex subsystem, debugging code
mutex implementation - add debugging code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
diff --git a/kernel/mutex-debug.h b/kernel/mutex-debug.h
new file mode 100644
index 0000000..fd38405
--- /dev/null
+++ b/kernel/mutex-debug.h
@@ -0,0 +1,134 @@
+/*
+ * Mutexes: blocking mutual exclusion locks
+ *
+ * started by Ingo Molnar:
+ *
+ * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *
+ * This file contains mutex debugging related internal declarations,
+ * prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case.
+ * More details are in kernel/mutex-debug.c.
+ */
+
+extern spinlock_t debug_mutex_lock;
+extern struct list_head debug_mutex_held_locks;
+extern int debug_mutex_on;
+
+/*
+ * In the debug case we carry the caller's instruction pointer into
+ * other functions, but we dont want the function argument overhead
+ * in the nondebug case - hence these macros:
+ */
+#define __IP_DECL__ , unsigned long ip
+#define __IP__ , ip
+#define __RET_IP__ , (unsigned long)__builtin_return_address(0)
+
+/*
+ * This must be called with lock->wait_lock held.
+ */
+extern void debug_mutex_set_owner(struct mutex *lock,
+ struct thread_info *new_owner __IP_DECL__);
+
+static inline void debug_mutex_clear_owner(struct mutex *lock)
+{
+ lock->owner = NULL;
+}
+
+extern void debug_mutex_init_waiter(struct mutex_waiter *waiter);
+extern void debug_mutex_wake_waiter(struct mutex *lock,
+ struct mutex_waiter *waiter);
+extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
+extern void debug_mutex_add_waiter(struct mutex *lock,
+ struct mutex_waiter *waiter,
+ struct thread_info *ti __IP_DECL__);
+extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+ struct thread_info *ti);
+extern void debug_mutex_unlock(struct mutex *lock);
+extern void debug_mutex_init(struct mutex *lock, const char *name);
+
+#define debug_spin_lock(lock) \
+ do { \
+ local_irq_disable(); \
+ if (debug_mutex_on) \
+ spin_lock(lock); \
+ } while (0)
+
+#define debug_spin_unlock(lock) \
+ do { \
+ if (debug_mutex_on) \
+ spin_unlock(lock); \
+ local_irq_enable(); \
+ preempt_check_resched(); \
+ } while (0)
+
+#define debug_spin_lock_save(lock, flags) \
+ do { \
+ local_irq_save(flags); \
+ if (debug_mutex_on) \
+ spin_lock(lock); \
+ } while (0)
+
+#define debug_spin_lock_restore(lock, flags) \
+ do { \
+ if (debug_mutex_on) \
+ spin_unlock(lock); \
+ local_irq_restore(flags); \
+ preempt_check_resched(); \
+ } while (0)
+
+#define spin_lock_mutex(lock) \
+ do { \
+ struct mutex *l = container_of(lock, struct mutex, wait_lock); \
+ \
+ DEBUG_WARN_ON(in_interrupt()); \
+ debug_spin_lock(&debug_mutex_lock); \
+ spin_lock(lock); \
+ DEBUG_WARN_ON(l->magic != l); \
+ } while (0)
+
+#define spin_unlock_mutex(lock) \
+ do { \
+ spin_unlock(lock); \
+ debug_spin_unlock(&debug_mutex_lock); \
+ } while (0)
+
+#define DEBUG_OFF() \
+do { \
+ if (debug_mutex_on) { \
+ debug_mutex_on = 0; \
+ console_verbose(); \
+ if (spin_is_locked(&debug_mutex_lock)) \
+ spin_unlock(&debug_mutex_lock); \
+ } \
+} while (0)
+
+#define DEBUG_BUG() \
+do { \
+ if (debug_mutex_on) { \
+ DEBUG_OFF(); \
+ BUG(); \
+ } \
+} while (0)
+
+#define DEBUG_WARN_ON(c) \
+do { \
+ if (unlikely(c && debug_mutex_on)) { \
+ DEBUG_OFF(); \
+ WARN_ON(1); \
+ } \
+} while (0)
+
+# define DEBUG_BUG_ON(c) \
+do { \
+ if (unlikely(c)) \
+ DEBUG_BUG(); \
+} while (0)
+
+#ifdef CONFIG_SMP
+# define SMP_DEBUG_WARN_ON(c) DEBUG_WARN_ON(c)
+# define SMP_DEBUG_BUG_ON(c) DEBUG_BUG_ON(c)
+#else
+# define SMP_DEBUG_WARN_ON(c) do { } while (0)
+# define SMP_DEBUG_BUG_ON(c) do { } while (0)
+#endif
+