[RFC][PATCH 1/3] rt_mutex: Add lockdep annotations
From: Peter Zijlstra
Date: Wed May 31 2017 - 11:22:43 EST
Now that (PI) futexes have their own private RT-mutex interface and
implementation we can easily add lockdep annotations to the existing
RT-mutex interface.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/rtmutex.h | 25 +++++++++++++++++++++----
kernel/locking/rtmutex-debug.c | 6 +++++-
kernel/locking/rtmutex-debug.h | 2 +-
kernel/locking/rtmutex.c | 36 +++++++++++++++++++++++++++++-------
kernel/locking/rtmutex.h | 2 +-
lib/Kconfig.debug | 3 +++
6 files changed, 60 insertions(+), 14 deletions(-)
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -37,6 +37,9 @@ struct rt_mutex {
int line;
void *magic;
#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
};
struct rt_mutex_waiter;
@@ -58,19 +61,33 @@ struct hrtimer_sleeper;
#ifdef CONFIG_DEBUG_RT_MUTEXES
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
, .name = #mutexname, .file = __FILE__, .line = __LINE__
-# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__)
+
+# define rt_mutex_init(mutex) \
+do { \
+ static struct lock_class_key __key; \
+ __rt_mutex_init(mutex, __func__, &__key); \
+} while (0)
+
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
#else
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
-# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL)
+# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL, NULL)
# define rt_mutex_debug_task_free(t) do { } while (0)
#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \
+ , .dep_map = { .name = #mutexname }
+#else
+#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
+#endif
+
#define __RT_MUTEX_INITIALIZER(mutexname) \
{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
, .waiters = RB_ROOT \
, .owner = NULL \
- __DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
+ __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
+ __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
#define DEFINE_RT_MUTEX(mutexname) \
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
@@ -86,7 +103,7 @@ static inline int rt_mutex_is_locked(str
return lock->owner != NULL;
}
-extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
+extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
extern void rt_mutex_destroy(struct rt_mutex *lock);
extern void rt_mutex_lock(struct rt_mutex *lock);
--- a/kernel/locking/rtmutex-debug.c
+++ b/kernel/locking/rtmutex-debug.c
@@ -166,12 +166,16 @@ void debug_rt_mutex_free_waiter(struct r
memset(waiter, 0x22, sizeof(*waiter));
}
-void debug_rt_mutex_init(struct rt_mutex *lock, const char *name)
+void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key)
{
/*
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lock->name = name;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
}
--- a/kernel/locking/rtmutex-debug.h
+++ b/kernel/locking/rtmutex-debug.h
@@ -11,7 +11,7 @@
extern void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
extern void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter);
-extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name);
+extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
extern void debug_rt_mutex_lock(struct rt_mutex *lock);
extern void debug_rt_mutex_unlock(struct rt_mutex *lock);
extern void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1481,6 +1481,7 @@ void __sched rt_mutex_lock(struct rt_mut
{
might_sleep();
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);
@@ -1496,9 +1497,16 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock);
*/
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
+ int ret;
+
might_sleep();
- return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
@@ -1526,11 +1534,18 @@ int __sched rt_mutex_futex_trylock(struc
int
rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout)
{
+ int ret;
+
might_sleep();
- return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
RT_MUTEX_MIN_CHAINWALK,
rt_mutex_slowlock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
@@ -1547,10 +1562,16 @@ EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
*/
int __sched rt_mutex_trylock(struct rt_mutex *lock)
{
+ int ret;
+
if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
return 0;
- return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+ ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+ if (ret)
+ mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(rt_mutex_trylock);
@@ -1561,6 +1582,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_trylock);
*/
void __sched rt_mutex_unlock(struct rt_mutex *lock)
{
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
@@ -1620,7 +1642,6 @@ void rt_mutex_destroy(struct rt_mutex *l
lock->magic = NULL;
#endif
}
-
EXPORT_SYMBOL_GPL(rt_mutex_destroy);
/**
@@ -1632,14 +1653,15 @@ EXPORT_SYMBOL_GPL(rt_mutex_destroy);
*
* Initializing of a locked rt lock is not allowed
*/
-void __rt_mutex_init(struct rt_mutex *lock, const char *name)
+void __rt_mutex_init(struct rt_mutex *lock, const char *name,
+ struct lock_class_key *key)
{
lock->owner = NULL;
raw_spin_lock_init(&lock->wait_lock);
lock->waiters = RB_ROOT;
lock->waiters_leftmost = NULL;
- debug_rt_mutex_init(lock, name);
+ debug_rt_mutex_init(lock, name, key);
}
EXPORT_SYMBOL_GPL(__rt_mutex_init);
@@ -1660,7 +1682,7 @@ EXPORT_SYMBOL_GPL(__rt_mutex_init);
void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner)
{
- __rt_mutex_init(lock, NULL);
+ __rt_mutex_init(lock, NULL, NULL);
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner);
}
--- a/kernel/locking/rtmutex.h
+++ b/kernel/locking/rtmutex.h
@@ -17,7 +17,7 @@
#define debug_rt_mutex_proxy_lock(l,p) do { } while (0)
#define debug_rt_mutex_proxy_unlock(l) do { } while (0)
#define debug_rt_mutex_unlock(l) do { } while (0)
-#define debug_rt_mutex_init(m, n) do { } while (0)
+#define debug_rt_mutex_init(m, n, k) do { } while (0)
#define debug_rt_mutex_deadlock(d, a ,l) do { } while (0)
#define debug_rt_mutex_print_deadlock(w) do { } while (0)
#define debug_rt_mutex_reset_waiter(w) do { } while (0)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1052,6 +1052,7 @@ config DEBUG_LOCK_ALLOC
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
select DEBUG_SPINLOCK
select DEBUG_MUTEXES
+ select DEBUG_RT_MUTEXES if RT_MUTEXES
select LOCKDEP
help
This feature will check whether any held lock (spinlock, rwlock,
@@ -1067,6 +1068,7 @@ config PROVE_LOCKING
select LOCKDEP
select DEBUG_SPINLOCK
select DEBUG_MUTEXES
+ select DEBUG_RT_MUTEXES if RT_MUTEXES
select DEBUG_LOCK_ALLOC
select TRACE_IRQFLAGS
default n
@@ -1121,6 +1123,7 @@ config LOCK_STAT
select LOCKDEP
select DEBUG_SPINLOCK
select DEBUG_MUTEXES
+ select DEBUG_RT_MUTEXES if RT_MUTEXES
select DEBUG_LOCK_ALLOC
default n
help