ARM: tegra11: clock: Fix boot over-clocking warnings
[linux-2.6.git] / kernel / rtmutex-debug.c
1 /*
2  * RT-Mutexes: blocking mutual exclusion locks with PI support
3  *
4  * started by Ingo Molnar and Thomas Gleixner:
5  *
6  *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
7  *  Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
8  *
9  * This code is based on the rt.c implementation in the preempt-rt tree.
10  * Portions of said code are
11  *
12  *  Copyright (C) 2004  LynuxWorks, Inc., Igor Manyilov, Bill Huey
13  *  Copyright (C) 2006  Esben Nielsen
14  *  Copyright (C) 2006  Kihon Technologies Inc.,
15  *                      Steven Rostedt <rostedt@goodmis.org>
16  *
17  * See rt.c in preempt-rt for proper credits and further information
18  */
19 #include <linux/sched.h>
20 #include <linux/delay.h>
21 #include <linux/export.h>
22 #include <linux/spinlock.h>
23 #include <linux/kallsyms.h>
24 #include <linux/syscalls.h>
25 #include <linux/interrupt.h>
26 #include <linux/plist.h>
27 #include <linux/fs.h>
28 #include <linux/debug_locks.h>
29
30 #include "rtmutex_common.h"
31
32 static void printk_task(struct task_struct *p)
33 {
34         if (p)
35                 printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio);
36         else
37                 printk("<none>");
38 }
39
40 static void printk_lock(struct rt_mutex *lock, int print_owner)
41 {
42         if (lock->name)
43                 printk(" [%p] {%s}\n",
44                         lock, lock->name);
45         else
46                 printk(" [%p] {%s:%d}\n",
47                         lock, lock->file, lock->line);
48
49         if (print_owner && rt_mutex_owner(lock)) {
50                 printk(".. ->owner: %p\n", lock->owner);
51                 printk(".. held by:  ");
52                 printk_task(rt_mutex_owner(lock));
53                 printk("\n");
54         }
55 }
56
57 void rt_mutex_debug_task_free(struct task_struct *task)
58 {
59         DEBUG_LOCKS_WARN_ON(!plist_head_empty(&task->pi_waiters));
60         DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
61 }
62
63 /*
64  * We fill out the fields in the waiter to store the information about
65  * the deadlock. We print when we return. act_waiter can be NULL in
66  * case of a remove waiter operation.
67  */
68 void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *act_waiter,
69                              struct rt_mutex *lock)
70 {
71         struct task_struct *task;
72
73         if (!debug_locks || detect || !act_waiter)
74                 return;
75
76         task = rt_mutex_owner(act_waiter->lock);
77         if (task && task != current) {
78                 act_waiter->deadlock_task_pid = get_pid(task_pid(task));
79                 act_waiter->deadlock_lock = lock;
80         }
81 }
82
83 void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
84 {
85         struct task_struct *task;
86
87         if (!waiter->deadlock_lock || !debug_locks)
88                 return;
89
90         rcu_read_lock();
91         task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
92         if (!task) {
93                 rcu_read_unlock();
94                 return;
95         }
96
97         if (!debug_locks_off()) {
98                 rcu_read_unlock();
99                 return;
100         }
101
102         printk("\n============================================\n");
103         printk(  "[ BUG: circular locking deadlock detected! ]\n");
104         printk("%s\n", print_tainted());
105         printk(  "--------------------------------------------\n");
106         printk("%s/%d is deadlocking current task %s/%d\n\n",
107                task->comm, task_pid_nr(task),
108                current->comm, task_pid_nr(current));
109
110         printk("\n1) %s/%d is trying to acquire this lock:\n",
111                current->comm, task_pid_nr(current));
112         printk_lock(waiter->lock, 1);
113
114         printk("\n2) %s/%d is blocked on this lock:\n",
115                 task->comm, task_pid_nr(task));
116         printk_lock(waiter->deadlock_lock, 1);
117
118         debug_show_held_locks(current);
119         debug_show_held_locks(task);
120
121         printk("\n%s/%d's [blocked] stackdump:\n\n",
122                 task->comm, task_pid_nr(task));
123         show_stack(task, NULL);
124         printk("\n%s/%d's [current] stackdump:\n\n",
125                 current->comm, task_pid_nr(current));
126         dump_stack();
127         debug_show_all_locks();
128         rcu_read_unlock();
129
130         printk("[ turning off deadlock detection."
131                "Please report this trace. ]\n\n");
132 }
133
134 void debug_rt_mutex_lock(struct rt_mutex *lock)
135 {
136 }
137
138 void debug_rt_mutex_unlock(struct rt_mutex *lock)
139 {
140         DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
141 }
142
143 void
144 debug_rt_mutex_proxy_lock(struct rt_mutex *lock, struct task_struct *powner)
145 {
146 }
147
148 void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
149 {
150         DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
151 }
152
153 void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
154 {
155         memset(waiter, 0x11, sizeof(*waiter));
156         plist_node_init(&waiter->list_entry, MAX_PRIO);
157         plist_node_init(&waiter->pi_list_entry, MAX_PRIO);
158         waiter->deadlock_task_pid = NULL;
159 }
160
161 void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
162 {
163         put_pid(waiter->deadlock_task_pid);
164         DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter->list_entry));
165         DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
166         memset(waiter, 0x22, sizeof(*waiter));
167 }
168
169 void debug_rt_mutex_init(struct rt_mutex *lock, const char *name)
170 {
171         /*
172          * Make sure we are not reinitializing a held lock:
173          */
174         debug_check_no_locks_freed((void *)lock, sizeof(*lock));
175         lock->name = name;
176 }
177
178 void
179 rt_mutex_deadlock_account_lock(struct rt_mutex *lock, struct task_struct *task)
180 {
181 }
182
183 void rt_mutex_deadlock_account_unlock(struct task_struct *task)
184 {
185 }
186