From d2e1446d81725c351dc73a03b397ce043fb18452 Mon Sep 17 00:00:00 2001
From: Meizu OpenSource <patchwork@meizu.com>
Date: Mon, 15 Aug 2016 10:19:42 +0800
Subject: first commit

---
 kernel/mutex-debug.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 kernel/mutex-debug.c

(limited to 'kernel/mutex-debug.c')

diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
new file mode 100644
index 000000000..b88ca48e7
--- /dev/null
+++ b/kernel/mutex-debug.c
@@ -0,0 +1,141 @@
+/*
+ * kernel/mutex-debug.c
+ *
+ * Debugging code for mutexes
+ *
+ * Started by Ingo Molnar:
+ *
+ *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *
+ * lock debugging, locking tree, deadlock detection started by:
+ *
+ *  Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ *  Released under the General Public License (GPL).
+ */
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/poison.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+#include <linux/debug_locks.h>
+
+#include "mutex-debug.h"
+
+/*
+ * Must be called with lock->wait_lock held.
+ */
+void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
+{
+	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
+	waiter->magic = waiter;
+	INIT_LIST_HEAD(&waiter->list);
+}
+
+void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
+{
+	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
+    if(DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list))){
+        printk("[MUTEX WARN!!]\n");
+    }
+    if(DEBUG_LOCKS_WARN_ON(waiter->magic != waiter)){
+        printk("[MUTEX WARN!!] bad magic number %p:%p\n", waiter->magic, waiter);
+    }
+    if(DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list))){
+        printk("[MUTEX WARN!!] empt waiter list\n");
+    }
+}
+
+void debug_mutex_free_waiter(struct mutex_waiter *waiter)
+{
+	DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
+	memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
+}
+
+void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+			    struct thread_info *ti)
+{
+	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
+
+	/* Mark the current thread as blocked on the lock: */
+	ti->task->blocked_on = waiter;
+#ifdef CONFIG_MT_DEBUG_MUTEXES
+    waiter->task_wait_on = lock->owner;
+#endif
+}
+
+void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+			 struct thread_info *ti)
+{
+    if(DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list))){
+        printk("[MUTEX WARN!!] empty waiter list\n");
+    }
+    if(DEBUG_LOCKS_WARN_ON(waiter->task != ti->task)){
+        printk("[MUTEX WARN!!] waiter task is not the same![%d:%s] != [%d:%s]\n", waiter->task->pid, waiter->task->comm, ti->task->pid, ti->task->comm);
+    }
+    if(DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter)){
+        printk("[MUTEX WARN!!] blocked on different waiter\n");
+    }
+	ti->task->blocked_on = NULL;
+
+	list_del_init(&waiter->list);
+	waiter->task = NULL;
+#ifdef CONFIG_MT_DEBUG_MUTEXES
+    waiter->task_wait_on = NULL;
+#endif
+}
+
+void debug_mutex_unlock(struct mutex *lock)
+{
+//	if (unlikely(!debug_locks))
+//		return;
+
+    if(DEBUG_LOCKS_WARN_ON(lock->magic != lock)){
+        printk("[MUTEX WARN!!] bad lock magic:%p\n", lock->magic);
+    }
+    if(DEBUG_LOCKS_WARN_ON(lock->owner != current)){
+        if(lock->owner != NULL){
+            printk("[MUTEX WARN!!] releasing mutex which is hold by another process, %p\n", lock->owner);
+            printk("[MUTEX WARN!!] current process[%d:%s] is trying to release lock\n But it should be released by lock owner-process[%d:%s]\n", current->pid, current->comm, lock->owner->pid, lock->owner->comm);
+        }else
+            printk("\n[MUTEX WARN!!] imbalanced unlock\n");
+    }
+    if(DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next)){
+        printk("[MUTEX WARN!!] wait_list both empty in prev and next \n");
+    }
+	mutex_clear_owner(lock);
+}
+
+void debug_mutex_init(struct mutex *lock, const char *name,
+		      struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+	lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+#ifdef CONFIG_DEBUG_MUTEXES
+    lock->name = name;
+#endif
+	lock->magic = lock;
+}
+
+/***
+ * mutex_destroy - mark a mutex unusable
+ * @lock: the mutex to be destroyed
+ *
+ * This function marks the mutex uninitialized, and any subsequent
+ * use of the mutex is forbidden. The mutex must not be locked when
+ * this function is called.
+ */
+void mutex_destroy(struct mutex *lock)
+{
+	DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
+	lock->magic = NULL;
+}
+
+EXPORT_SYMBOL_GPL(mutex_destroy);
-- 
cgit v1.2.3