Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / kernel / locking / rtmutex-debug.c

diff --git a/kernel/kernel/locking/rtmutex-debug.c b/kernel/kernel/locking/rtmutex-debug.c
new file mode 100644 (file)
index 0000000..62b6cee
--- /dev/null
+++ b/kernel/kernel/locking/rtmutex-debug.c
@@ -0,0 +1,184 @@
+/*
+ * RT-Mutexes: blocking mutual exclusion locks with PI support
+ *
+ * started by Ingo Molnar and Thomas Gleixner:
+ *
+ *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * This code is based on the rt.c implementation in the preempt-rt tree.
+ * Portions of said code are
+ *
+ *  Copyright (C) 2004  LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ *  Copyright (C) 2006  Esben Nielsen
+ *  Copyright (C) 2006  Kihon Technologies Inc.,
+ *                     Steven Rostedt <rostedt@goodmis.org>
+ *
+ * See rt.c in preempt-rt for proper credits and further information
+ */
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/rbtree.h>
+#include <linux/fs.h>
+#include <linux/debug_locks.h>
+
+#include "rtmutex_common.h"
+
+static void printk_task(struct task_struct *p)
+{
+       if (p)
+               printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio);
+       else
+               printk("<none>");
+}
+
+static void printk_lock(struct rt_mutex *lock, int print_owner)
+{
+       if (lock->name)
+               printk(" [%p] {%s}\n",
+                       lock, lock->name);
+       else
+               printk(" [%p] {%s:%d}\n",
+                       lock, lock->file, lock->line);
+
+       if (print_owner && rt_mutex_owner(lock)) {
+               printk(".. ->owner: %p\n", lock->owner);
+               printk(".. held by:  ");
+               printk_task(rt_mutex_owner(lock));
+               printk("\n");
+       }
+}
+
+void rt_mutex_debug_task_free(struct task_struct *task)
+{
+       DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters));
+       DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
+}
+
+/*
+ * We fill out the fields in the waiter to store the information about
+ * the deadlock. We print when we return. act_waiter can be NULL in
+ * case of a remove waiter operation.
+ */
+void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk,
+                            struct rt_mutex_waiter *act_waiter,
+                            struct rt_mutex *lock)
+{
+       struct task_struct *task;
+
+       if (!debug_locks || chwalk == RT_MUTEX_FULL_CHAINWALK || !act_waiter)
+               return;
+
+       task = rt_mutex_owner(act_waiter->lock);
+       if (task && task != current) {
+               act_waiter->deadlock_task_pid = get_pid(task_pid(task));
+               act_waiter->deadlock_lock = lock;
+       }
+}
+
+void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
+{
+       struct task_struct *task;
+
+       if (!waiter->deadlock_lock || !debug_locks)
+               return;
+
+       rcu_read_lock();
+       task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
+       if (!task) {
+               rcu_read_unlock();
+               return;
+       }
+
+       if (!debug_locks_off()) {
+               rcu_read_unlock();
+               return;
+       }
+
+       printk("\n============================================\n");
+       printk(  "[ BUG: circular locking deadlock detected! ]\n");
+       printk("%s\n", print_tainted());
+       printk(  "--------------------------------------------\n");
+       printk("%s/%d is deadlocking current task %s/%d\n\n",
+              task->comm, task_pid_nr(task),
+              current->comm, task_pid_nr(current));
+
+       printk("\n1) %s/%d is trying to acquire this lock:\n",
+              current->comm, task_pid_nr(current));
+       printk_lock(waiter->lock, 1);
+
+       printk("\n2) %s/%d is blocked on this lock:\n",
+               task->comm, task_pid_nr(task));
+       printk_lock(waiter->deadlock_lock, 1);
+
+       debug_show_held_locks(current);
+       debug_show_held_locks(task);
+
+       printk("\n%s/%d's [blocked] stackdump:\n\n",
+               task->comm, task_pid_nr(task));
+       show_stack(task, NULL);
+       printk("\n%s/%d's [current] stackdump:\n\n",
+               current->comm, task_pid_nr(current));
+       dump_stack();
+       debug_show_all_locks();
+       rcu_read_unlock();
+
+       printk("[ turning off deadlock detection."
+              "Please report this trace. ]\n\n");
+}
+
+void debug_rt_mutex_lock(struct rt_mutex *lock)
+{
+}
+
+void debug_rt_mutex_unlock(struct rt_mutex *lock)
+{
+       DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
+}
+
+void
+debug_rt_mutex_proxy_lock(struct rt_mutex *lock, struct task_struct *powner)
+{
+}
+
+void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
+{
+       DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
+}
+
+void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+{
+       memset(waiter, 0x11, sizeof(*waiter));
+       waiter->deadlock_task_pid = NULL;
+}
+
+void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
+{
+       put_pid(waiter->deadlock_task_pid);
+       memset(waiter, 0x22, sizeof(*waiter));
+}
+
+void debug_rt_mutex_init(struct rt_mutex *lock, const char *name)
+{
+       /*
+        * Make sure we are not reinitializing a held lock:
+        */
+       debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+       lock->name = name;
+}
+
+void
+rt_mutex_deadlock_account_lock(struct rt_mutex *lock, struct task_struct *task)
+{
+}
+
+void rt_mutex_deadlock_account_unlock(struct task_struct *task)
+{
+}
+