]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - kernel/rtmutex-debug.c
2 * RT-Mutexes: blocking mutual exclusion locks with PI support
4 * started by Ingo Molnar and Thomas Gleixner:
6 * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
7 * Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
9 * This code is based on the rt.c implementation in the preempt-rt tree.
10 * Portions of said code are
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>
17 * See rt.c in preempt-rt for proper credits and further information
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>
28 #include <linux/debug_locks.h>
30 #include "rtmutex_common.h"
32 static void printk_task(struct task_struct
*p
)
35 printk("%16s:%5d [%p, %3d]", p
->comm
, task_pid_nr(p
), p
, p
->prio
);
40 static void printk_lock(struct rt_mutex
*lock
, int print_owner
)
43 printk(" [%p] {%s}\n",
46 printk(" [%p] {%s:%d}\n",
47 lock
, lock
->file
, lock
->line
);
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
));
57 void rt_mutex_debug_task_free(struct task_struct
*task
)
59 DEBUG_LOCKS_WARN_ON(!plist_head_empty(&task
->pi_waiters
));
60 DEBUG_LOCKS_WARN_ON(task
->pi_blocked_on
);
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.
68 void debug_rt_mutex_deadlock(int detect
, struct rt_mutex_waiter
*act_waiter
,
69 struct rt_mutex
*lock
)
71 struct task_struct
*task
;
73 if (!debug_locks
|| detect
|| !act_waiter
)
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
;
83 void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter
*waiter
)
85 struct task_struct
*task
;
87 if (!waiter
->deadlock_lock
|| !debug_locks
)
91 task
= pid_task(waiter
->deadlock_task_pid
, PIDTYPE_PID
);
97 if (!debug_locks_off()) {
102 printk("\n============================================\n");
103 printk( "[ BUG: circular locking deadlock detected! ]\n");
104 printk( "--------------------------------------------\n");
105 printk("%s/%d is deadlocking current task %s/%d\n\n",
106 task
->comm
, task_pid_nr(task
),
107 current
->comm
, task_pid_nr(current
));
109 printk("\n1) %s/%d is trying to acquire this lock:\n",
110 current
->comm
, task_pid_nr(current
));
111 printk_lock(waiter
->lock
, 1);
113 printk("\n2) %s/%d is blocked on this lock:\n",
114 task
->comm
, task_pid_nr(task
));
115 printk_lock(waiter
->deadlock_lock
, 1);
117 debug_show_held_locks(current
);
118 debug_show_held_locks(task
);
120 printk("\n%s/%d's [blocked] stackdump:\n\n",
121 task
->comm
, task_pid_nr(task
));
122 show_stack(task
, NULL
);
123 printk("\n%s/%d's [current] stackdump:\n\n",
124 current
->comm
, task_pid_nr(current
));
126 debug_show_all_locks();
129 printk("[ turning off deadlock detection."
130 "Please report this trace. ]\n\n");
133 void debug_rt_mutex_lock(struct rt_mutex
*lock
)
137 void debug_rt_mutex_unlock(struct rt_mutex
*lock
)
139 DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock
) != current
);
143 debug_rt_mutex_proxy_lock(struct rt_mutex
*lock
, struct task_struct
*powner
)
147 void debug_rt_mutex_proxy_unlock(struct rt_mutex
*lock
)
149 DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock
));
152 void debug_rt_mutex_init_waiter(struct rt_mutex_waiter
*waiter
)
154 memset(waiter
, 0x11, sizeof(*waiter
));
155 plist_node_init(&waiter
->list_entry
, MAX_PRIO
);
156 plist_node_init(&waiter
->pi_list_entry
, MAX_PRIO
);
157 waiter
->deadlock_task_pid
= NULL
;
160 void debug_rt_mutex_free_waiter(struct rt_mutex_waiter
*waiter
)
162 put_pid(waiter
->deadlock_task_pid
);
163 DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter
->list_entry
));
164 DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter
->pi_list_entry
));
165 memset(waiter
, 0x22, sizeof(*waiter
));
168 void debug_rt_mutex_init(struct rt_mutex
*lock
, const char *name
)
171 * Make sure we are not reinitializing a held lock:
173 debug_check_no_locks_freed((void *)lock
, sizeof(*lock
));
178 rt_mutex_deadlock_account_lock(struct rt_mutex
*lock
, struct task_struct
*task
)
182 void rt_mutex_deadlock_account_unlock(struct task_struct
*task
)