[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>

2 files changed, 26 insertions, 0 deletions

diff --git a/include/linux/mutex-debug.h b/include/linux/mutex-debug.h
new file mode 100644
index 000000000000..0ccd8f983b50
--- /dev/null
+++ b/include/linux/mutex-debug.h
@@ -0,0 +1,21 @@
+#ifndef __LINUX_MUTEX_DEBUG_H
+#define __LINUX_MUTEX_DEBUG_H
+
+/*
+ * Mutexes - debugging helpers:
+ */
+
+#define __DEBUG_MUTEX_INITIALIZER(lockname) \
+        , .held_list = LIST_HEAD_INIT(lockname.held_list), \
+          .name = #lockname , .magic = &lockname
+
+#define mutex_init(sem)         __mutex_init(sem, __FUNCTION__)
+
+extern void FASTCALL(mutex_destroy(struct mutex *lock));
+
+extern void mutex_debug_show_all_locks(void);
+extern void mutex_debug_show_held_locks(struct task_struct *filter);
+extern void mutex_debug_check_no_locks_held(struct task_struct *task);
+extern void mutex_debug_check_no_locks_freed(const void *from, const void *to);
+
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 78eb92ae4d94..85b53f87c703 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -817,6 +817,11 @@ struct task_struct {
 /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
         spinlock_t proc_lock;
 
+#ifdef CONFIG_DEBUG_MUTEXES
+        /* mutex deadlock detection */
+        struct mutex_waiter *blocked_on;
+#endif
+
 /* journalling filesystem info */
         void *journal_info;