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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 13 Aug 2021 13:49:49 +0200
Subject: [PATCH 04/10] rtmutex: Add rt_mutex_lock_nest_lock() and
rt_mutex_lock_killable().
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.15/older/patches-5.15.3-rt21.tar.xz
The locking selftest for ww-mutex expects to operate directly on the
base-mutex which becomes a rtmutex on PREEMPT_RT.
Add rt_mutex_lock_nest_lock(), follows mutex_lock_nest_lock() for
rtmutex.
Add rt_mutex_lock_killable(), follows mutex_lock_killable() for rtmutex.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/rtmutex.h | 9 +++++++++
kernel/locking/rtmutex_api.c | 30 ++++++++++++++++++++++++++----
2 files changed, 35 insertions(+), 4 deletions(-)
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -99,13 +99,22 @@ extern void __rt_mutex_init(struct rt_mu
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
+extern void _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock);
#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
+#define rt_mutex_lock_nest_lock(lock, nest_lock) \
+ do { \
+ typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
+ _rt_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
+ } while (0)
+
#else
extern void rt_mutex_lock(struct rt_mutex *lock);
#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
+#define rt_mutex_lock_nest_lock(lock, nest_lock) rt_mutex_lock(lock)
#endif
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
extern int rt_mutex_trylock(struct rt_mutex *lock);
extern void rt_mutex_unlock(struct rt_mutex *lock);
--- a/kernel/locking/rtmutex_api.c
+++ b/kernel/locking/rtmutex_api.c
@@ -21,12 +21,13 @@ int max_lock_depth = 1024;
*/
static __always_inline int __rt_mutex_lock_common(struct rt_mutex *lock,
unsigned int state,
+ struct lockdep_map *nest_lock,
unsigned int subclass)
{
int ret;
might_sleep();
- mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, _RET_IP_);
ret = __rt_mutex_lock(&lock->rtmutex, state);
if (ret)
mutex_release(&lock->dep_map, _RET_IP_);
@@ -48,10 +49,16 @@ EXPORT_SYMBOL(rt_mutex_base_init);
*/
void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass)
{
- __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass);
+ __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, NULL, subclass);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
+void __sched _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock)
+{
+ __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, nest_lock, 0);
+}
+EXPORT_SYMBOL_GPL(_rt_mutex_lock_nest_lock);
+
#else /* !CONFIG_DEBUG_LOCK_ALLOC */
/**
@@ -61,7 +68,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
*/
void __sched rt_mutex_lock(struct rt_mutex *lock)
{
- __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0);
+ __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, NULL, 0);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);
#endif
@@ -77,11 +84,26 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock);
*/
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
- return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0);
+ return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, NULL, 0);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock: the rt_mutex to be locked
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+ return __rt_mutex_lock_common(lock, TASK_KILLABLE, NULL, 0);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
* rt_mutex_trylock - try to lock a rt_mutex
*
* @lock: the rt_mutex to be locked
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