mutex implementation, core files: just the basic subsystem, no users of it.
Signed-off-by: Ingo Molnar <[email protected]>
----
include/linux/mutex.h | 102 ++++++++
include/linux/preempt.h | 1
include/linux/sched.h | 5
kernel/Makefile | 2
kernel/fork.c | 4
kernel/mutex.c | 564 ++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 677 insertions(+), 1 deletion(-)
Index: linux/include/linux/mutex.h
===================================================================
--- /dev/null
+++ linux/include/linux/mutex.h
@@ -0,0 +1,102 @@
+#ifndef __LINUX_MUTEX_H
+#define __LINUX_MUTEX_H
+
+/*
+ * Mutexes
+ *
+ * started by Ingo Molnar:
+ *
+ * Copyright (C) 2004, 2005 Red Hat, Inc., Ingo Molnar <[email protected]>
+ *
+ * This file contains the main data structure and API definitions.
+ */
+#include <linux/config.h>
+#include <asm/atomic.h>
+#include <linux/list.h>
+#include <linux/spinlock_types.h>
+
+/*
+ * Simple, straightforward mutexes with strict semantics:
+ *
+ * - only one task can hold the mutex at a time
+ * - only the owner can unlock the mutex
+ * - multiple unlocks are not permitted
+ * - recursive locking is not permitted
+ * - a mutex object must be initialized via the API
+ * - a mutex object must not be initialized via memset or copying
+ * - task may not exit with mutex held
+ * - memory areas where held locks reside must not be freed
+ *
+ * These semantics are fully enforced when DEBUG_MUTEXESS is
+ * enabled. Furthermore, besides enforcing the above rules, the mutex
+ * debugging code also implements a number of additional features
+ * that make lock debugging easier and faster:
+ *
+ * - uses symbolic names of mutexes, whenever they are printed in debug output
+ * - point-of-acquire tracking, symbolic lookup of function names
+ * - list of all locks held in the system, printout of them
+ * - owner tracking
+ * - detects self-recursing locks and prints out all relevant info
+ * - detects multi-task circular deadlocks and prints out all affected
+ * locks and tasks (and only those tasks)
+ */
+struct mutex {
+ // 1: unlocked, 0: locked, negative: locked, possibly waiters
+ atomic_t count;
+ spinlock_t wait_lock;
+ struct list_head wait_list;
+#ifdef CONFIG_DEBUG_MUTEXESS
+ struct thread_info *owner;
+ struct list_head held_list;
+ unsigned long acquire_ip;
+ char *name, *file;
+ int line;
+ void *magic;
+#endif
+};
+
+/*
+ * This is the control structure for tasks blocked on mutex,
+ * which resides on the blocked task's kernel stack:
+ */
+struct mutex_waiter {
+ struct mutex *lock;
+ struct list_head list;
+ struct thread_info *ti;
+ int woken;
+#ifdef CONFIG_DEBUG_MUTEXESS
+ unsigned long ip;
+ void *magic;
+#endif
+};
+
+#ifdef CONFIG_DEBUG_MUTEXESS
+# define __MUTEX_DEADLOCK_DETECT_INITIALIZER(lockname) \
+ , .held_list = LIST_HEAD_INIT(lockname.held_list), \
+ .name = #lockname, .file = __FILE__, .line = __LINE__ , \
+ .magic = &lockname
+extern void FASTCALL(__mutex_init(struct mutex *lock, char *name,
+ char *file, int line));
+# define mutex_init(sem) __mutex_init(sem, NULL, __FILE__, __LINE__)
+#else
+# define __MUTEX_DEADLOCK_DETECT_INITIALIZER(lockname)
+extern void FASTCALL(__mutex_init(struct mutex *lock));
+# define mutex_init(sem) __mutex_init(sem)
+#endif
+
+#define __MUTEX_INITIALIZER(lockname) \
+ { .count = ATOMIC_INIT(1) \
+ , .wait_lock = SPIN_LOCK_UNLOCKED \
+ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \
+ __MUTEX_DEADLOCK_DETECT_INITIALIZER(lockname) }
+
+#define DEFINE_MUTEX(mutexname) \
+ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void FASTCALL(mutex_lock(struct mutex *lock));
+extern int FASTCALL(mutex_lock_interruptible(struct mutex *lock));
+extern int FASTCALL(mutex_trylock(struct mutex *lock));
+extern void FASTCALL(mutex_unlock(struct mutex *lock));
+extern int FASTCALL(mutex_is_locked(struct mutex *lock));
+
+#endif
Index: linux/include/linux/preempt.h
===================================================================
--- linux.orig/include/linux/preempt.h
+++ linux/include/linux/preempt.h
@@ -22,6 +22,7 @@
#define dec_preempt_count() sub_preempt_count(1)
#define preempt_count() (current_thread_info()->preempt_count)
+#define preempt_count_ti(ti) ((ti)->preempt_count)
#ifdef CONFIG_PREEMPT
Index: linux/include/linux/sched.h
===================================================================
--- linux.orig/include/linux/sched.h
+++ linux/include/linux/sched.h
@@ -820,6 +820,11 @@ struct task_struct {
/* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
spinlock_t proc_lock;
+#ifdef CONFIG_DEBUG_MUTEXESS
+ /* mutex deadlock detection */
+ struct mutex_waiter *blocked_on;
+#endif
+
/* journalling filesystem info */
void *journal_info;
Index: linux/kernel/Makefile
===================================================================
--- linux.orig/kernel/Makefile
+++ linux/kernel/Makefile
@@ -7,7 +7,7 @@ obj-y = sched.o fork.o exec_domain.o
sysctl.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o intermodule.o extable.o params.o posix-timers.o \
- kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o
+ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
Index: linux/kernel/fork.c
===================================================================
--- linux.orig/kernel/fork.c
+++ linux/kernel/fork.c
@@ -973,6 +973,10 @@ static task_t *copy_process(unsigned lon
}
#endif
+#ifdef CONFIG_DEBUG_MUTEXESS
+ p->blocked_on = NULL; /* not blocked yet */
+#endif
+
p->tgid = p->pid;
if (clone_flags & CLONE_THREAD)
p->tgid = current->tgid;
Index: linux/kernel/mutex.c
===================================================================
--- /dev/null
+++ linux/kernel/mutex.c
@@ -0,0 +1,564 @@
+/*
+ * kernel/mutex.c
+ *
+ * Mutexes
+ *
+ * Started by Ingo Molnar:
+ *
+ * Copyright (C) 2004, 2005 Red Hat, Inc., Ingo Molnar <[email protected]>
+ *
+ * Many thanks to Arjan van de Ven, Thomas Gleixner, Steven Rostedt and
+ * David Howells for suggestions and improvements.
+ */
+#include <linux/config.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+
+/*
+ * We can speed up the lock-acquire, if the architecture
+ * supports cmpxchg and if there's no debugging state
+ * to be set up (!DEBUG_MUTEXESS).
+ *
+ * trick: we can use cmpxchg on the release side too, if bit
+ * 0 of lock->owner is set if there is at least a single pending
+ * task in the wait_list. This way the release atomic-fastpath
+ * can be a mirror image of the acquire path:
+ */
+#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_MUTEXESS)
+# define MUTEX_LOCKLESS_FASTPATH
+#endif
+
+/*
+ * In the debug case we carry the caller's instruction pointer into
+ * other functions, but we dont want the function argument overhead
+ * in the nondebug case - hence these macros:
+ */
+#ifdef CONFIG_DEBUG_MUTEXESS
+# define __IP_DECL__ , unsigned long ip
+# define __IP__ , ip
+# define __W_CALLER__(waiter) , (waiter)->ip
+# define __CALLER_IP__ , (unsigned long)__builtin_return_address(0)
+#else
+# define __IP_DECL__
+# define __IP__
+# define __W_CALLER__(waiter)
+# define __CALLER_IP__
+#endif
+
+#ifdef CONFIG_DEBUG_MUTEXESS
+# include "mutex-debug.c"
+#else /* !CONFIG_DEBUG_MUTEXESS */
+
+// #define MUTEX_IRQ_SAFE
+
+#ifdef MUTEX_IRQ_SAFE
+# define mutex_irq_disable() local_irq_disable()
+# define mutex_irq_enable() local_irq_enable()
+# define mutex_irq_save(flags) local_irq_save(flags)
+# define mutex_irq_restore(flags) local_irq_restore(flags)
+#else
+# define mutex_irq_disable() preempt_disable()
+# define mutex_irq_enable() preempt_enable()
+# define mutex_irq_save(flags) \
+ do { (void)(flags); preempt_disable(); } while (0)
+# define mutex_irq_restore(flags) \
+ do { (void)(flags); preempt_enable(); } while (0)
+#endif
+
+# define debug_lock_irq(lock, ti) \
+ do { mutex_irq_disable(); (void)(ti); } while (0)
+# define debug_lock_irqsave(lock, flags, ti) \
+ do { mutex_irq_save(flags); (void)(ti); } while (0)
+# define debug_unlock_irq(lock, ti) mutex_irq_enable()
+# define debug_unlock_irqrestore(lock, flags, ti) \
+ do { \
+ (void)(ti); \
+ mutex_irq_restore(flags); \
+ preempt_check_resched(); \
+ } while (0)
+# define debug_mutex_irq_disable(ti) mutex_irq_disable()
+# define debug_mutex_irq_enable(ti) mutex_irq_enable()
+# define debug_mutex_irq_restore(flags, ti) mutex_irq_restore(flags)
+
+# define debug_unlock(lock, ti) do { } while (0)
+
+# define DEBUG_BUG() do { } while (0)
+# define DEBUG_WARN_ON(c) do { } while (0)
+# define DEBUG_OFF() do { } while (0)
+# define DEBUG_BUG_ON(c) do { } while (0)
+
+static inline void
+debug_set_owner(struct mutex *lock, struct thread_info *new_owner)
+{
+}
+
+static inline void debug_init_waiter(struct mutex_waiter *waiter)
+{
+}
+
+static inline void debug_free_waiter(struct mutex_waiter *waiter)
+{
+}
+
+#endif /* !CONFIG_DEBUG_MUTEXESS */
+
+#ifdef CONFIG_SMP
+# define SMP_DEBUG_WARN_ON(c) DEBUG_WARN_ON(c)
+# define SMP_DEBUG_BUG_ON(c) DEBUG_BUG_ON(c)
+#else
+# define SMP_DEBUG_WARN_ON(c) do { } while (0)
+# define SMP_DEBUG_BUG_ON(c) do { } while (0)
+#endif
+
+/*
+ * Block on a lock - add ourselves to the list of waiters.
+ * Called with lock->wait_lock held.
+ */
+static inline void
+__add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+ struct thread_info *ti, struct task_struct *task __IP_DECL__)
+{
+#ifdef CONFIG_DEBUG_MUTEXESS
+ debug_init_waiter(waiter);
+ SMP_DEBUG_WARN_ON(!spin_is_locked(&lock->wait_lock));
+ check_deadlock(lock, 0, ti, ip);
+ waiter->ip = ip;
+ /* Mark the current thread as blocked on the lock: */
+ task->blocked_on = waiter;
+#endif
+ waiter->woken = 0;
+ waiter->lock = lock;
+ waiter->ti = ti;
+
+ /* Add waiting tasks to the end of the waitqueue (FIFO): */
+ list_add_tail(&waiter->list, &lock->wait_list);
+}
+
+
+static inline void
+__remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+ struct thread_info *ti, struct task_struct *task)
+{
+#ifdef CONFIG_DEBUG_MUTEXESS
+ DEBUG_WARN_ON(list_empty(&waiter->list));
+ DEBUG_WARN_ON(waiter->ti != ti);
+ DEBUG_WARN_ON(task->blocked_on != waiter);
+ task->blocked_on = NULL;
+#endif
+ list_del_init(&waiter->list);
+ waiter->ti = NULL;
+}
+
+static inline void
+remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
+ struct thread_info *ti, struct task_struct *task)
+{
+ unsigned long flags;
+
+ debug_lock_irqsave(&debug_lock, flags, ti);
+
+ spin_lock(&lock->wait_lock);
+ __remove_waiter(lock, waiter, ti, task);
+ spin_unlock(&lock->wait_lock);
+
+ debug_unlock_irqrestore(&debug_lock, flags, ti);
+ debug_free_waiter(waiter);
+}
+
+/*
+ * Lock a mutex, common slowpath. We just decremented the count,
+ * and it got negative as a result.
+ */
+static inline int
+__mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter,
+ struct thread_info *ti, struct task_struct *task,
+ unsigned long *flags, unsigned long task_state __IP_DECL__)
+{
+ unsigned int old_val;
+
+ debug_lock_irqsave(&debug_lock, *flags, ti);
+ DEBUG_WARN_ON(lock->magic != lock);
+
+ spin_lock(&lock->wait_lock);
+ __add_waiter(lock, waiter, ti, task __IP__);
+ set_task_state(task, task_state);
+
+ /*
+ * Lets try to take the lock again - this is needed even if
+ * we get here for the first time (shortly after failing to
+ * acquire the lock), to make sure that we get a wakeup once
+ * it's unlocked. Later on this is the operation that gives
+ * us the lock. We need to xchg it to -1, so that when we
+ * release the lock, we properly wake up other waiters!
+ */
+ old_val = atomic_xchg(&lock->count, -1);
+
+ if (old_val == 1) {
+ /*
+ * Got the lock! Rejoice:
+ */
+ debug_set_owner(lock, ti __IP__);
+ __remove_waiter(lock, waiter, ti, task);
+
+ spin_unlock(&lock->wait_lock);
+ __set_task_state(task, TASK_RUNNING);
+
+ debug_unlock_irqrestore(&debug_lock, *flags, ti);
+ debug_free_waiter(waiter);
+ DEBUG_WARN_ON(list_empty(&lock->held_list));
+ DEBUG_WARN_ON(lock->owner != ti);
+
+ return 1;
+ }
+
+ /*
+ * Ok, didnt get the lock - we'll go to sleep after return:
+ */
+ spin_unlock(&lock->wait_lock);
+
+ debug_unlock_irqrestore(&debug_lock, *flags, ti);
+
+ return 0;
+}
+
+/*
+ * Lock the mutex:
+ */
+static inline void __mutex_lock_nonatomic(struct mutex *lock __IP_DECL__)
+{
+ struct thread_info *ti = current_thread_info();
+ struct task_struct *task = ti->task;
+ struct mutex_waiter waiter;
+ unsigned long flags;
+
+repeat:
+ if (__mutex_lock_common(lock, &waiter, ti, task, &flags,
+ TASK_UNINTERRUPTIBLE __IP__))
+ return;
+
+ /* wait to be woken up */
+ schedule();
+
+ remove_waiter(lock, &waiter, ti, task);
+
+ goto repeat;
+}
+
+/*
+ * Wake up a task and make it the new owner of the mutex:
+ */
+static inline void
+__mutex_wakeup_waiter(struct mutex *lock __IP_DECL__)
+{
+ struct mutex_waiter *waiter;
+
+ SMP_DEBUG_WARN_ON(!spin_is_locked(&lock->wait_lock));
+ DEBUG_WARN_ON(list_empty(&lock->wait_list));
+
+ /*
+ * Get the first entry from the wait-list:
+ */
+ waiter = list_entry(lock->wait_list.next, struct mutex_waiter, list);
+
+ DEBUG_WARN_ON(waiter->magic != waiter);
+ DEBUG_WARN_ON(list_empty(&waiter->list));
+
+ if (!waiter->woken) {
+ waiter->woken = 1;
+ wake_up_process(waiter->ti->task);
+ }
+}
+
+/*
+ * Helper functions for mutex_lock_interruptible() timeouts:
+ */
+
+static void process_timeout(unsigned long __data)
+{
+ wake_up_process((task_t *)__data);
+}
+
+static inline void
+start_mutex_timer(struct timer_list *timer, unsigned long time,
+ unsigned long *expire)
+{
+ *expire = time + jiffies;
+ init_timer(timer);
+ timer->expires = *expire;
+ timer->data = (unsigned long)current;
+ timer->function = process_timeout;
+ add_timer(timer);
+}
+
+static inline int
+stop_mutex_timer(struct timer_list *timer, unsigned long time,
+ unsigned long expire)
+{
+ int ret;
+
+ ret = (int)(expire - jiffies);
+ if (!timer_pending(timer)) {
+ del_singleshot_timer_sync(timer);
+ ret = -ETIMEDOUT;
+ }
+ return ret;
+}
+
+/*
+ * Lock a mutex interruptible, with timeouts:
+ */
+static int __sched
+__mutex_lock_interruptible(struct mutex *lock, unsigned long time __IP_DECL__)
+{
+ struct thread_info *ti = current_thread_info();
+ struct task_struct *task = ti->task;
+ unsigned long expire = 0, flags;
+ struct mutex_waiter waiter;
+ struct timer_list timer;
+ int ret;
+
+repeat:
+ if (__mutex_lock_common(lock, &waiter, ti, task, &flags,
+ TASK_INTERRUPTIBLE __IP__))
+ return 0;
+
+ if (time)
+ start_mutex_timer(&timer, time, &expire);
+
+ /* wait to be given the lock */
+ if (!signal_pending(task) && (!time || timer_pending(&timer))) {
+ schedule();
+
+ remove_waiter(lock, &waiter, ti, task);
+ goto repeat;
+ }
+ /*
+ * We got a signal or timed out. Remove ourselves from
+ * the wait list:
+ */
+ ret = -EINTR;
+ if (time)
+ ret = stop_mutex_timer(&timer, time, expire);
+
+ debug_lock_irq(&debug_lock, ti);
+ DEBUG_WARN_ON(lock->magic != lock);
+
+ spin_lock(&lock->wait_lock);
+ __remove_waiter(lock, &waiter, ti, task);
+ /*
+ * If there are other waiters then wake
+ * one up:
+ */
+ if (unlikely(!list_empty(&lock->wait_list)))
+ __mutex_wakeup_waiter(lock __IP__);
+
+ spin_unlock(&lock->wait_lock);
+ __set_task_state(task, TASK_RUNNING);
+
+ debug_unlock_irq(&debug_lock, ti);
+ debug_free_waiter(&waiter);
+
+ return ret;
+}
+
+/*
+ * Mutex trylock, returns 1 if successful, 0 if contention
+ */
+static int __mutex_trylock(struct mutex *lock __IP_DECL__)
+{
+#ifdef MUTEX_LOCKLESS_FASTPATH
+ if (atomic_cmpxchg(&lock->count, 1, 0) == 1)
+ return 1;
+ return 0;
+#else
+ struct thread_info *ti = current_thread_info();
+ unsigned long flags;
+ int ret = 0;
+
+ debug_lock_irqsave(&debug_lock, flags, ti);
+ spin_lock(&lock->wait_lock);
+ DEBUG_WARN_ON(lock->magic != lock);
+
+ if (atomic_read(&lock->count) == 1) {
+ atomic_set(&lock->count, 0);
+ debug_set_owner(lock, ti __IP__);
+ ret = 1;
+ }
+ spin_unlock(&lock->wait_lock);
+ debug_unlock_irqrestore(&debug_lock, flags, ti);
+
+ return ret;
+#endif
+}
+
+int fastcall mutex_is_locked(struct mutex *lock)
+{
+ mb();
+ return atomic_read(&lock->count) != 1;
+}
+
+EXPORT_SYMBOL_GPL(mutex_is_locked);
+
+int __sched fastcall mutex_trylock(struct mutex *lock)
+{
+ return __mutex_trylock(lock __CALLER_IP__);
+}
+
+/*
+ * Release the lock:
+ */
+static inline void __mutex_unlock_nonatomic(struct mutex *lock __IP_DECL__)
+{
+ struct thread_info *ti = current_thread_info();
+ unsigned long flags;
+
+ debug_lock_irqsave(&debug_lock, flags, ti);
+ spin_lock(&lock->wait_lock);
+
+#ifdef CONFIG_DEBUG_MUTEXESS
+ DEBUG_WARN_ON(lock->magic != lock);
+ DEBUG_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
+ DEBUG_WARN_ON(lock->owner != ti);
+ if (debug_on) {
+ DEBUG_WARN_ON(list_empty(&lock->held_list));
+ list_del_init(&lock->held_list);
+ }
+#endif
+
+ if (unlikely(!list_empty(&lock->wait_list)))
+ __mutex_wakeup_waiter(lock __IP__);
+#ifdef CONFIG_DEBUG_MUTEXESS
+ lock->owner = NULL;
+#endif
+ /*
+ * Set it back to 'unlocked'. We'll have a waiter in flight
+ * (if any), and if some other task comes around, let it
+ * steal the lock. Waiters take care of themselves and stay
+ * in flight until necessary.
+ */
+ atomic_set(&lock->count, 1);
+
+ spin_unlock(&lock->wait_lock);
+ debug_unlock_irqrestore(&debug_lock, flags, ti);
+}
+
+#ifdef MUTEX_LOCKLESS_FASTPATH
+
+/*
+ * We split it into a fastpath and a separate slowpath function,
+ * to reduce the register pressure on the fastpath:
+ *
+ * We want the atomic op come first, to make sure the
+ * branch is predicted as default-untaken:
+ */
+static __sched void FASTCALL(__mutex_lock_noinline(atomic_t *lock_count));
+
+/*
+ * The locking fastpath is the 1->0 transition from
+ * 'unlocked' into 'locked' state:
+ */
+static inline void __mutex_lock_atomic(struct mutex *lock)
+{
+ atomic_dec_call_if_negative(&lock->count, __mutex_lock_noinline);
+}
+
+static fastcall __sched void __mutex_lock_noinline(atomic_t *lock_count)
+{
+ struct mutex *lock = container_of(lock_count, struct mutex, count);
+
+ __mutex_lock_nonatomic(lock);
+}
+
+static inline void __mutex_lock(struct mutex *lock)
+{
+ __mutex_lock_atomic(lock);
+}
+
+static void __sched FASTCALL(__mutex_unlock_noinline(atomic_t *lock_count));
+
+/*
+ * The unlocking fastpath is the 0->1 transition from
+ * 'locked' into 'unlocked' state:
+ */
+static inline void __mutex_unlock_atomic(struct mutex *lock)
+{
+ atomic_inc_call_if_nonpositive(&lock->count, __mutex_unlock_noinline);
+}
+
+static fastcall void __sched __mutex_unlock_noinline(atomic_t *lock_count)
+{
+ struct mutex *lock = container_of(lock_count, struct mutex, count);
+
+ __mutex_unlock_nonatomic(lock);
+}
+
+static inline void __mutex_unlock(struct mutex *lock)
+{
+ __mutex_unlock_atomic(lock);
+}
+
+#else
+
+static inline void __mutex_lock(struct mutex *lock __IP_DECL__)
+{
+ __mutex_lock_nonatomic(lock __IP__);
+}
+
+static inline void __mutex_unlock(struct mutex *lock __IP_DECL__)
+{
+ __mutex_unlock_nonatomic(lock __IP__);
+}
+
+#endif
+
+void __sched fastcall mutex_lock(struct mutex *lock)
+{
+ __mutex_lock(lock __CALLER_IP__);
+}
+
+EXPORT_SYMBOL_GPL(mutex_lock);
+
+void __sched fastcall mutex_unlock(struct mutex *lock)
+{
+ DEBUG_WARN_ON(lock->owner != current_thread_info());
+ __mutex_unlock(lock __CALLER_IP__);
+}
+
+EXPORT_SYMBOL_GPL(mutex_unlock);
+
+int __sched fastcall mutex_lock_interruptible(struct mutex *lock)
+{
+ return __mutex_lock_interruptible(lock, 0 __CALLER_IP__);
+}
+
+EXPORT_SYMBOL_GPL(mutex_lock_interruptible);
+
+/*
+ * Initialise the lock:
+ */
+void fastcall __mutex_init(struct mutex *lock
+#ifdef CONFIG_DEBUG_MUTEXESS
+ , char *name, char *file, int line
+#endif
+ )
+{
+ atomic_set(&lock->count, 1);
+ spin_lock_init(&lock->wait_lock);
+ INIT_LIST_HEAD(&lock->wait_list);
+#ifdef CONFIG_DEBUG_MUTEXESS
+ lock->owner = NULL;
+ INIT_LIST_HEAD(&lock->held_list);
+ lock->name = name;
+ lock->file = file;
+ lock->line = line;
+ lock->magic = lock;
+#endif
+
+}
+EXPORT_SYMBOL_GPL(__mutex_init);
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