| .. | .. |
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| 32 | 32 | |
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| 33 | 33 | #include "rtmutex_common.h" |
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| 34 | 34 | |
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| 35 | +static void printk_task(struct task_struct *p) |
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| 36 | +{ |
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| 37 | + if (p) |
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| 38 | + printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio); |
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| 39 | + else |
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| 40 | + printk("<none>"); |
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| 41 | +} |
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| 42 | + |
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| 43 | +static void printk_lock(struct rt_mutex *lock, int print_owner) |
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| 44 | +{ |
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| 45 | + if (lock->name) |
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| 46 | + printk(" [%p] {%s}\n", |
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| 47 | + lock, lock->name); |
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| 48 | + else |
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| 49 | + printk(" [%p] {%s:%d}\n", |
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| 50 | + lock, lock->file, lock->line); |
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| 51 | + |
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| 52 | + if (print_owner && rt_mutex_owner(lock)) { |
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| 53 | + printk(".. ->owner: %p\n", lock->owner); |
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| 54 | + printk(".. held by: "); |
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| 55 | + printk_task(rt_mutex_owner(lock)); |
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| 56 | + printk("\n"); |
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| 57 | + } |
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| 58 | +} |
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| 59 | + |
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| 35 | 60 | void rt_mutex_debug_task_free(struct task_struct *task) |
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| 36 | 61 | { |
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| 37 | 62 | DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root)); |
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| 38 | 63 | DEBUG_LOCKS_WARN_ON(task->pi_blocked_on); |
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| 64 | +} |
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| 65 | + |
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| 66 | +/* |
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| 67 | + * We fill out the fields in the waiter to store the information about |
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| 68 | + * the deadlock. We print when we return. act_waiter can be NULL in |
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| 69 | + * case of a remove waiter operation. |
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| 70 | + */ |
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| 71 | +void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk, |
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| 72 | + struct rt_mutex_waiter *act_waiter, |
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| 73 | + struct rt_mutex *lock) |
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| 74 | +{ |
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| 75 | + struct task_struct *task; |
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| 76 | + |
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| 77 | + if (!debug_locks || chwalk == RT_MUTEX_FULL_CHAINWALK || !act_waiter) |
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| 78 | + return; |
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| 79 | + |
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| 80 | + task = rt_mutex_owner(act_waiter->lock); |
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| 81 | + if (task && task != current) { |
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| 82 | + act_waiter->deadlock_task_pid = get_pid(task_pid(task)); |
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| 83 | + act_waiter->deadlock_lock = lock; |
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| 84 | + } |
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| 85 | +} |
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| 86 | + |
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| 87 | +void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter) |
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| 88 | +{ |
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| 89 | + struct task_struct *task; |
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| 90 | + |
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| 91 | + if (!waiter->deadlock_lock || !debug_locks) |
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| 92 | + return; |
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| 93 | + |
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| 94 | + rcu_read_lock(); |
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| 95 | + task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID); |
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| 96 | + if (!task) { |
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| 97 | + rcu_read_unlock(); |
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| 98 | + return; |
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| 99 | + } |
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| 100 | + |
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| 101 | + if (!debug_locks_off()) { |
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| 102 | + rcu_read_unlock(); |
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| 103 | + return; |
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| 104 | + } |
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| 105 | + |
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| 106 | + pr_warn("\n"); |
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| 107 | + pr_warn("============================================\n"); |
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| 108 | + pr_warn("WARNING: circular locking deadlock detected!\n"); |
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| 109 | + pr_warn("%s\n", print_tainted()); |
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| 110 | + pr_warn("--------------------------------------------\n"); |
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| 111 | + printk("%s/%d is deadlocking current task %s/%d\n\n", |
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| 112 | + task->comm, task_pid_nr(task), |
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| 113 | + current->comm, task_pid_nr(current)); |
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| 114 | + |
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| 115 | + printk("\n1) %s/%d is trying to acquire this lock:\n", |
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| 116 | + current->comm, task_pid_nr(current)); |
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| 117 | + printk_lock(waiter->lock, 1); |
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| 118 | + |
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| 119 | + printk("\n2) %s/%d is blocked on this lock:\n", |
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| 120 | + task->comm, task_pid_nr(task)); |
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| 121 | + printk_lock(waiter->deadlock_lock, 1); |
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| 122 | + |
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| 123 | + debug_show_held_locks(current); |
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| 124 | + debug_show_held_locks(task); |
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| 125 | + |
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| 126 | + printk("\n%s/%d's [blocked] stackdump:\n\n", |
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| 127 | + task->comm, task_pid_nr(task)); |
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| 128 | + show_stack(task, NULL, KERN_DEFAULT); |
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| 129 | + printk("\n%s/%d's [current] stackdump:\n\n", |
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| 130 | + current->comm, task_pid_nr(current)); |
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| 131 | + dump_stack(); |
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| 132 | + debug_show_all_locks(); |
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| 133 | + rcu_read_unlock(); |
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| 134 | + |
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| 135 | + printk("[ turning off deadlock detection." |
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| 136 | + "Please report this trace. ]\n\n"); |
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| 39 | 137 | } |
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| 40 | 138 | |
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| 41 | 139 | void debug_rt_mutex_lock(struct rt_mutex *lock) |
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| .. | .. |
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| 60 | 158 | void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) |
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| 61 | 159 | { |
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| 62 | 160 | memset(waiter, 0x11, sizeof(*waiter)); |
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| 161 | + waiter->deadlock_task_pid = NULL; |
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| 63 | 162 | } |
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| 64 | 163 | |
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| 65 | 164 | void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter) |
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| 66 | 165 | { |
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| 166 | + put_pid(waiter->deadlock_task_pid); |
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| 67 | 167 | memset(waiter, 0x22, sizeof(*waiter)); |
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| 68 | 168 | } |
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| 69 | 169 | |
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| .. | .. |
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| 73 | 173 | * Make sure we are not reinitializing a held lock: |
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| 74 | 174 | */ |
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| 75 | 175 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
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| 176 | + lock->name = name; |
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| 76 | 177 | |
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| 77 | 178 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
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| 78 | 179 | lockdep_init_map(&lock->dep_map, name, key, 0); |
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| 79 | 180 | #endif |
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| 80 | 181 | } |
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| 182 | + |
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