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-rw-r--r--patches/rtmutex-add-sleeping-lock-implementation.patch1195
1 files changed, 1195 insertions, 0 deletions
diff --git a/patches/rtmutex-add-sleeping-lock-implementation.patch b/patches/rtmutex-add-sleeping-lock-implementation.patch
new file mode 100644
index 000000000000..defdb62ebfbf
--- /dev/null
+++ b/patches/rtmutex-add-sleeping-lock-implementation.patch
@@ -0,0 +1,1195 @@
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 12 Oct 2017 17:11:19 +0200
+Subject: rtmutex: add sleeping lock implementation
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ include/linux/kernel.h | 4
+ include/linux/rtmutex.h | 20 +
+ include/linux/sched.h | 9
+ include/linux/sched/wake_q.h | 27 ++
+ include/linux/spinlock_rt.h | 159 +++++++++++++
+ include/linux/spinlock_types_rt.h | 48 ++++
+ kernel/fork.c | 1
+ kernel/futex.c | 11
+ kernel/locking/rtmutex.c | 449 ++++++++++++++++++++++++++++++++++----
+ kernel/locking/rtmutex_common.h | 15 +
+ kernel/sched/core.c | 28 +-
+ 11 files changed, 712 insertions(+), 59 deletions(-)
+ create mode 100644 include/linux/spinlock_rt.h
+ create mode 100644 include/linux/spinlock_types_rt.h
+
+--- a/include/linux/kernel.h
++++ b/include/linux/kernel.h
+@@ -203,6 +203,9 @@ extern int _cond_resched(void);
+ */
+ # define might_sleep() \
+ do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
++
++# define might_sleep_no_state_check() \
++ do { ___might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
+ # define sched_annotate_sleep() (current->task_state_change = 0)
+ #else
+ static inline void ___might_sleep(const char *file, int line,
+@@ -210,6 +213,7 @@ extern int _cond_resched(void);
+ static inline void __might_sleep(const char *file, int line,
+ int preempt_offset) { }
+ # define might_sleep() do { might_resched(); } while (0)
++# define might_sleep_no_state_check() do { might_resched(); } while (0)
+ # define sched_annotate_sleep() do { } while (0)
+ #endif
+
+--- a/include/linux/rtmutex.h
++++ b/include/linux/rtmutex.h
+@@ -13,11 +13,15 @@
+ #define __LINUX_RT_MUTEX_H
+
+ #include <linux/linkage.h>
+-#include <linux/rbtree.h>
+ #include <linux/spinlock_types_raw.h>
++#include <linux/rbtree.h>
+
+ extern int max_lock_depth; /* for sysctl */
+
++#ifdef CONFIG_DEBUG_MUTEXES
++#include <linux/debug_locks.h>
++#endif
++
+ /**
+ * The rt_mutex structure
+ *
+@@ -31,8 +35,8 @@ struct rt_mutex {
+ struct rb_root waiters;
+ struct rb_node *waiters_leftmost;
+ struct task_struct *owner;
+-#ifdef CONFIG_DEBUG_RT_MUTEXES
+ int save_state;
++#ifdef CONFIG_DEBUG_RT_MUTEXES
+ const char *name, *file;
+ int line;
+ void *magic;
+@@ -82,16 +86,22 @@ do { \
+ #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
+ #endif
+
+-#define __RT_MUTEX_INITIALIZER(mutexname) \
+- { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
++#define __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
++ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
+ , .waiters = RB_ROOT \
+ , .owner = NULL \
+ __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
+- __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
++ __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
++
++#define __RT_MUTEX_INITIALIZER(mutexname) \
++ { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) }
+
+ #define DEFINE_RT_MUTEX(mutexname) \
+ struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
+
++#define __RT_MUTEX_INITIALIZER_SAVE_STATE(mutexname) \
++ { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
++ , .save_state = 1 }
+ /**
+ * rt_mutex_is_locked - is the mutex locked
+ * @lock: the mutex to be queried
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -123,6 +123,11 @@ struct task_group;
+ smp_store_mb(current->state, (state_value)); \
+ } while (0)
+
++#define __set_current_state_no_track(state_value) \
++ current->state = (state_value);
++#define set_current_state_no_track(state_value) \
++ smp_store_mb(current->state, (state_value));
++
+ #else
+ /*
+ * set_current_state() includes a barrier so that the write of current->state
+@@ -160,6 +165,9 @@ struct task_group;
+ */
+ #define __set_current_state(state_value) do { current->state = (state_value); } while (0)
+ #define set_current_state(state_value) smp_store_mb(current->state, (state_value))
++
++#define __set_current_state_no_track(state_value) __set_current_state(state_value)
++#define set_current_state_no_track(state_value) set_current_state(state_value)
+ #endif
+
+ /* Task command name length: */
+@@ -826,6 +834,7 @@ struct task_struct {
+ raw_spinlock_t pi_lock;
+
+ struct wake_q_node wake_q;
++ struct wake_q_node wake_q_sleeper;
+
+ #ifdef CONFIG_RT_MUTEXES
+ /* PI waiters blocked on a rt_mutex held by this task: */
+--- a/include/linux/sched/wake_q.h
++++ b/include/linux/sched/wake_q.h
+@@ -46,8 +46,29 @@ static inline void wake_q_init(struct wa
+ head->lastp = &head->first;
+ }
+
+-extern void wake_q_add(struct wake_q_head *head,
+- struct task_struct *task);
+-extern void wake_up_q(struct wake_q_head *head);
++extern void __wake_q_add(struct wake_q_head *head,
++ struct task_struct *task, bool sleeper);
++static inline void wake_q_add(struct wake_q_head *head,
++ struct task_struct *task)
++{
++ __wake_q_add(head, task, false);
++}
++
++static inline void wake_q_add_sleeper(struct wake_q_head *head,
++ struct task_struct *task)
++{
++ __wake_q_add(head, task, true);
++}
++
++extern void __wake_up_q(struct wake_q_head *head, bool sleeper);
++static inline void wake_up_q(struct wake_q_head *head)
++{
++ __wake_up_q(head, false);
++}
++
++static inline void wake_up_q_sleeper(struct wake_q_head *head)
++{
++ __wake_up_q(head, true);
++}
+
+ #endif /* _LINUX_SCHED_WAKE_Q_H */
+--- /dev/null
++++ b/include/linux/spinlock_rt.h
+@@ -0,0 +1,159 @@
++#ifndef __LINUX_SPINLOCK_RT_H
++#define __LINUX_SPINLOCK_RT_H
++
++#ifndef __LINUX_SPINLOCK_H
++#error Do not include directly. Use spinlock.h
++#endif
++
++#include <linux/bug.h>
++
++extern void
++__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key);
++
++#define spin_lock_init(slock) \
++do { \
++ static struct lock_class_key __key; \
++ \
++ rt_mutex_init(&(slock)->lock); \
++ __rt_spin_lock_init(slock, #slock, &__key); \
++} while (0)
++
++extern void __lockfunc rt_spin_lock(spinlock_t *lock);
++extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
++extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
++extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
++extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
++extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
++extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
++extern int __lockfunc rt_spin_trylock(spinlock_t *lock);
++extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock);
++
++/*
++ * lockdep-less calls, for derived types like rwlock:
++ * (for trylock they can use rt_mutex_trylock() directly.
++ * Migrate disable handling must be done at the call site.
++ */
++extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
++extern void __lockfunc __rt_spin_trylock(struct rt_mutex *lock);
++extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
++
++#define spin_lock(lock) rt_spin_lock(lock)
++
++#define spin_lock_bh(lock) \
++ do { \
++ local_bh_disable(); \
++ rt_spin_lock(lock); \
++ } while (0)
++
++#define spin_lock_irq(lock) spin_lock(lock)
++
++#define spin_do_trylock(lock) __cond_lock(lock, rt_spin_trylock(lock))
++
++#define spin_trylock(lock) \
++({ \
++ int __locked; \
++ __locked = spin_do_trylock(lock); \
++ __locked; \
++})
++
++#ifdef CONFIG_LOCKDEP
++# define spin_lock_nested(lock, subclass) \
++ do { \
++ rt_spin_lock_nested(lock, subclass); \
++ } while (0)
++
++#define spin_lock_bh_nested(lock, subclass) \
++ do { \
++ local_bh_disable(); \
++ rt_spin_lock_nested(lock, subclass); \
++ } while (0)
++
++# define spin_lock_irqsave_nested(lock, flags, subclass) \
++ do { \
++ typecheck(unsigned long, flags); \
++ flags = 0; \
++ rt_spin_lock_nested(lock, subclass); \
++ } while (0)
++#else
++# define spin_lock_nested(lock, subclass) spin_lock(lock)
++# define spin_lock_bh_nested(lock, subclass) spin_lock_bh(lock)
++
++# define spin_lock_irqsave_nested(lock, flags, subclass) \
++ do { \
++ typecheck(unsigned long, flags); \
++ flags = 0; \
++ spin_lock(lock); \
++ } while (0)
++#endif
++
++#define spin_lock_irqsave(lock, flags) \
++ do { \
++ typecheck(unsigned long, flags); \
++ flags = 0; \
++ spin_lock(lock); \
++ } while (0)
++
++static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
++{
++ unsigned long flags = 0;
++#ifdef CONFIG_TRACE_IRQFLAGS
++ flags = rt_spin_lock_trace_flags(lock);
++#else
++ spin_lock(lock); /* lock_local */
++#endif
++ return flags;
++}
++
++/* FIXME: we need rt_spin_lock_nest_lock */
++#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
++
++#define spin_unlock(lock) rt_spin_unlock(lock)
++
++#define spin_unlock_bh(lock) \
++ do { \
++ rt_spin_unlock(lock); \
++ local_bh_enable(); \
++ } while (0)
++
++#define spin_unlock_irq(lock) spin_unlock(lock)
++
++#define spin_unlock_irqrestore(lock, flags) \
++ do { \
++ typecheck(unsigned long, flags); \
++ (void) flags; \
++ spin_unlock(lock); \
++ } while (0)
++
++#define spin_trylock_bh(lock) __cond_lock(lock, rt_spin_trylock_bh(lock))
++#define spin_trylock_irq(lock) spin_trylock(lock)
++
++#define spin_trylock_irqsave(lock, flags) \
++ rt_spin_trylock_irqsave(lock, &(flags))
++
++#define spin_unlock_wait(lock) rt_spin_unlock_wait(lock)
++
++#ifdef CONFIG_GENERIC_LOCKBREAK
++# define spin_is_contended(lock) ((lock)->break_lock)
++#else
++# define spin_is_contended(lock) (((void)(lock), 0))
++#endif
++
++static inline int spin_can_lock(spinlock_t *lock)
++{
++ return !rt_mutex_is_locked(&lock->lock);
++}
++
++static inline int spin_is_locked(spinlock_t *lock)
++{
++ return rt_mutex_is_locked(&lock->lock);
++}
++
++static inline void assert_spin_locked(spinlock_t *lock)
++{
++ BUG_ON(!spin_is_locked(lock));
++}
++
++#define atomic_dec_and_lock(atomic, lock) \
++ atomic_dec_and_spin_lock(atomic, lock)
++
++#endif
+--- /dev/null
++++ b/include/linux/spinlock_types_rt.h
+@@ -0,0 +1,48 @@
++#ifndef __LINUX_SPINLOCK_TYPES_RT_H
++#define __LINUX_SPINLOCK_TYPES_RT_H
++
++#ifndef __LINUX_SPINLOCK_TYPES_H
++#error "Do not include directly. Include spinlock_types.h instead"
++#endif
++
++#include <linux/cache.h>
++
++/*
++ * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field:
++ */
++typedef struct spinlock {
++ struct rt_mutex lock;
++ unsigned int break_lock;
++#ifdef CONFIG_DEBUG_LOCK_ALLOC
++ struct lockdep_map dep_map;
++#endif
++} spinlock_t;
++
++#ifdef CONFIG_DEBUG_RT_MUTEXES
++# define __RT_SPIN_INITIALIZER(name) \
++ { \
++ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
++ .save_state = 1, \
++ .file = __FILE__, \
++ .line = __LINE__ , \
++ }
++#else
++# define __RT_SPIN_INITIALIZER(name) \
++ { \
++ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
++ .save_state = 1, \
++ }
++#endif
++
++/*
++.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock)
++*/
++
++#define __SPIN_LOCK_UNLOCKED(name) \
++ { .lock = __RT_SPIN_INITIALIZER(name.lock), \
++ SPIN_DEP_MAP_INIT(name) }
++
++#define DEFINE_SPINLOCK(name) \
++ spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
++
++#endif
+--- a/kernel/fork.c
++++ b/kernel/fork.c
+@@ -592,6 +592,7 @@ static struct task_struct *dup_task_stru
+ tsk->splice_pipe = NULL;
+ tsk->task_frag.page = NULL;
+ tsk->wake_q.next = NULL;
++ tsk->wake_q_sleeper.next = NULL;
+
+ account_kernel_stack(tsk, 1);
+
+--- a/kernel/futex.c
++++ b/kernel/futex.c
+@@ -1411,6 +1411,7 @@ static int wake_futex_pi(u32 __user *uad
+ struct task_struct *new_owner;
+ bool postunlock = false;
+ DEFINE_WAKE_Q(wake_q);
++ DEFINE_WAKE_Q(wake_sleeper_q);
+ int ret = 0;
+
+ new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
+@@ -1472,13 +1473,13 @@ static int wake_futex_pi(u32 __user *uad
+ pi_state->owner = new_owner;
+ raw_spin_unlock(&new_owner->pi_lock);
+
+- postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q);
+-
++ postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q,
++ &wake_sleeper_q);
+ out_unlock:
+ raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
+
+ if (postunlock)
+- rt_mutex_postunlock(&wake_q);
++ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
+
+ return ret;
+ }
+@@ -2677,7 +2678,7 @@ static int futex_lock_pi(u32 __user *uad
+ goto no_block;
+ }
+
+- rt_mutex_init_waiter(&rt_waiter);
++ rt_mutex_init_waiter(&rt_waiter, false);
+
+ /*
+ * On PREEMPT_RT_FULL, when hb->lock becomes an rt_mutex, we must not
+@@ -3043,7 +3044,7 @@ static int futex_wait_requeue_pi(u32 __u
+ * The waiter is allocated on our stack, manipulated by the requeue
+ * code while we sleep on uaddr.
+ */
+- rt_mutex_init_waiter(&rt_waiter);
++ rt_mutex_init_waiter(&rt_waiter, false);
+
+ ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
+ if (unlikely(ret != 0))
+--- a/kernel/locking/rtmutex.c
++++ b/kernel/locking/rtmutex.c
+@@ -7,6 +7,11 @@
+ * Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ * Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
+ * Copyright (C) 2006 Esben Nielsen
++ * Adaptive Spinlocks:
++ * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
++ * and Peter Morreale,
++ * Adaptive Spinlocks simplification:
++ * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
+ *
+ * See Documentation/locking/rt-mutex-design.txt for details.
+ */
+@@ -234,7 +239,7 @@ static inline bool unlock_rt_mutex_safe(
+ * Only use with rt_mutex_waiter_{less,equal}()
+ */
+ #define task_to_waiter(p) \
+- &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline }
++ &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline, .task = (p) }
+
+ static inline int
+ rt_mutex_waiter_less(struct rt_mutex_waiter *left,
+@@ -274,6 +279,27 @@ rt_mutex_waiter_equal(struct rt_mutex_wa
+ return 1;
+ }
+
++#define STEAL_NORMAL 0
++#define STEAL_LATERAL 1
++
++static inline int
++rt_mutex_steal(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, int mode)
++{
++ struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock);
++
++ if (waiter == top_waiter || rt_mutex_waiter_less(waiter, top_waiter))
++ return 1;
++
++ /*
++ * Note that RT tasks are excluded from lateral-steals
++ * to prevent the introduction of an unbounded latency.
++ */
++ if (mode == STEAL_NORMAL || rt_task(waiter->task))
++ return 0;
++
++ return rt_mutex_waiter_equal(waiter, top_waiter);
++}
++
+ static void
+ rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
+ {
+@@ -390,6 +416,14 @@ static bool rt_mutex_cond_detect_deadloc
+ return debug_rt_mutex_detect_deadlock(waiter, chwalk);
+ }
+
++static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
++{
++ if (waiter->savestate)
++ wake_up_lock_sleeper(waiter->task);
++ else
++ wake_up_process(waiter->task);
++}
++
+ /*
+ * Max number of times we'll walk the boosting chain:
+ */
+@@ -715,13 +749,16 @@ static int rt_mutex_adjust_prio_chain(st
+ * follow here. This is the end of the chain we are walking.
+ */
+ if (!rt_mutex_owner(lock)) {
++ struct rt_mutex_waiter *lock_top_waiter;
++
+ /*
+ * If the requeue [7] above changed the top waiter,
+ * then we need to wake the new top waiter up to try
+ * to get the lock.
+ */
+- if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
+- wake_up_process(rt_mutex_top_waiter(lock)->task);
++ lock_top_waiter = rt_mutex_top_waiter(lock);
++ if (prerequeue_top_waiter != lock_top_waiter)
++ rt_mutex_wake_waiter(lock_top_waiter);
+ raw_spin_unlock_irq(&lock->wait_lock);
+ return 0;
+ }
+@@ -823,9 +860,11 @@ static int rt_mutex_adjust_prio_chain(st
+ * @task: The task which wants to acquire the lock
+ * @waiter: The waiter that is queued to the lock's wait tree if the
+ * callsite called task_blocked_on_lock(), otherwise NULL
++ * @mode: Lock steal mode (STEAL_NORMAL, STEAL_LATERAL)
+ */
+-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+- struct rt_mutex_waiter *waiter)
++static int __try_to_take_rt_mutex(struct rt_mutex *lock,
++ struct task_struct *task,
++ struct rt_mutex_waiter *waiter, int mode)
+ {
+ lockdep_assert_held(&lock->wait_lock);
+
+@@ -861,12 +900,11 @@ static int try_to_take_rt_mutex(struct r
+ */
+ if (waiter) {
+ /*
+- * If waiter is not the highest priority waiter of
+- * @lock, give up.
++ * If waiter is not the highest priority waiter of @lock,
++ * or its peer when lateral steal is allowed, give up.
+ */
+- if (waiter != rt_mutex_top_waiter(lock))
++ if (!rt_mutex_steal(lock, waiter, mode))
+ return 0;
+-
+ /*
+ * We can acquire the lock. Remove the waiter from the
+ * lock waiters tree.
+@@ -884,14 +922,12 @@ static int try_to_take_rt_mutex(struct r
+ */
+ if (rt_mutex_has_waiters(lock)) {
+ /*
+- * If @task->prio is greater than or equal to
+- * the top waiter priority (kernel view),
+- * @task lost.
++ * If @task->prio is greater than the top waiter
++ * priority (kernel view), or equal to it when a
++ * lateral steal is forbidden, @task lost.
+ */
+- if (!rt_mutex_waiter_less(task_to_waiter(task),
+- rt_mutex_top_waiter(lock)))
++ if (!rt_mutex_steal(lock, task_to_waiter(task), mode))
+ return 0;
+-
+ /*
+ * The current top waiter stays enqueued. We
+ * don't have to change anything in the lock
+@@ -938,6 +974,309 @@ static int try_to_take_rt_mutex(struct r
+ return 1;
+ }
+
++#ifdef CONFIG_PREEMPT_RT_FULL
++/*
++ * preemptible spin_lock functions:
++ */
++static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
++ void (*slowfn)(struct rt_mutex *lock))
++{
++ might_sleep_no_state_check();
++
++ if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
++ return;
++ else
++ slowfn(lock);
++}
++
++static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
++ void (*slowfn)(struct rt_mutex *lock))
++{
++ if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
++ return;
++ else
++ slowfn(lock);
++}
++#ifdef CONFIG_SMP
++/*
++ * Note that owner is a speculative pointer and dereferencing relies
++ * on rcu_read_lock() and the check against the lock owner.
++ */
++static int adaptive_wait(struct rt_mutex *lock,
++ struct task_struct *owner)
++{
++ int res = 0;
++
++ rcu_read_lock();
++ for (;;) {
++ if (owner != rt_mutex_owner(lock))
++ break;
++ /*
++ * Ensure that owner->on_cpu is dereferenced _after_
++ * checking the above to be valid.
++ */
++ barrier();
++ if (!owner->on_cpu) {
++ res = 1;
++ break;
++ }
++ cpu_relax();
++ }
++ rcu_read_unlock();
++ return res;
++}
++#else
++static int adaptive_wait(struct rt_mutex *lock,
++ struct task_struct *orig_owner)
++{
++ return 1;
++}
++#endif
++
++static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
++ struct rt_mutex_waiter *waiter,
++ struct task_struct *task,
++ enum rtmutex_chainwalk chwalk);
++/*
++ * Slow path lock function spin_lock style: this variant is very
++ * careful not to miss any non-lock wakeups.
++ *
++ * We store the current state under p->pi_lock in p->saved_state and
++ * the try_to_wake_up() code handles this accordingly.
++ */
++void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
++ struct rt_mutex_waiter *waiter,
++ unsigned long flags)
++{
++ struct task_struct *lock_owner, *self = current;
++ struct rt_mutex_waiter *top_waiter;
++ int ret;
++
++ if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL))
++ return;
++
++ BUG_ON(rt_mutex_owner(lock) == self);
++
++ /*
++ * We save whatever state the task is in and we'll restore it
++ * after acquiring the lock taking real wakeups into account
++ * as well. We are serialized via pi_lock against wakeups. See
++ * try_to_wake_up().
++ */
++ raw_spin_lock(&self->pi_lock);
++ self->saved_state = self->state;
++ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
++ raw_spin_unlock(&self->pi_lock);
++
++ ret = task_blocks_on_rt_mutex(lock, waiter, self, RT_MUTEX_MIN_CHAINWALK);
++ BUG_ON(ret);
++
++ for (;;) {
++ /* Try to acquire the lock again. */
++ if (__try_to_take_rt_mutex(lock, self, waiter, STEAL_LATERAL))
++ break;
++
++ top_waiter = rt_mutex_top_waiter(lock);
++ lock_owner = rt_mutex_owner(lock);
++
++ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
++
++ debug_rt_mutex_print_deadlock(waiter);
++
++ if (top_waiter != waiter || adaptive_wait(lock, lock_owner))
++ schedule();
++
++ raw_spin_lock_irqsave(&lock->wait_lock, flags);
++
++ raw_spin_lock(&self->pi_lock);
++ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
++ raw_spin_unlock(&self->pi_lock);
++ }
++
++ /*
++ * Restore the task state to current->saved_state. We set it
++ * to the original state above and the try_to_wake_up() code
++ * has possibly updated it when a real (non-rtmutex) wakeup
++ * happened while we were blocked. Clear saved_state so
++ * try_to_wakeup() does not get confused.
++ */
++ raw_spin_lock(&self->pi_lock);
++ __set_current_state_no_track(self->saved_state);
++ self->saved_state = TASK_RUNNING;
++ raw_spin_unlock(&self->pi_lock);
++
++ /*
++ * try_to_take_rt_mutex() sets the waiter bit
++ * unconditionally. We might have to fix that up:
++ */
++ fixup_rt_mutex_waiters(lock);
++
++ BUG_ON(rt_mutex_has_waiters(lock) && waiter == rt_mutex_top_waiter(lock));
++ BUG_ON(!RB_EMPTY_NODE(&waiter->tree_entry));
++}
++
++static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
++{
++ struct rt_mutex_waiter waiter;
++ unsigned long flags;
++
++ rt_mutex_init_waiter(&waiter, true);
++
++ raw_spin_lock_irqsave(&lock->wait_lock, flags);
++ rt_spin_lock_slowlock_locked(lock, &waiter, flags);
++ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
++ debug_rt_mutex_free_waiter(&waiter);
++}
++
++static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock,
++ struct wake_q_head *wake_q,
++ struct wake_q_head *wq_sleeper);
++/*
++ * Slow path to release a rt_mutex spin_lock style
++ */
++void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
++{
++ unsigned long flags;
++ DEFINE_WAKE_Q(wake_q);
++ DEFINE_WAKE_Q(wake_sleeper_q);
++ bool postunlock;
++
++ raw_spin_lock_irqsave(&lock->wait_lock, flags);
++ postunlock = __rt_mutex_unlock_common(lock, &wake_q, &wake_sleeper_q);
++ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
++
++ if (postunlock)
++ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
++}
++
++void __lockfunc rt_spin_lock(spinlock_t *lock)
++{
++ migrate_disable();
++ spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
++ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
++}
++EXPORT_SYMBOL(rt_spin_lock);
++
++void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
++{
++ rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock);
++}
++
++#ifdef CONFIG_DEBUG_LOCK_ALLOC
++void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
++{
++ migrate_disable();
++ spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
++ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
++}
++EXPORT_SYMBOL(rt_spin_lock_nested);
++#endif
++
++void __lockfunc rt_spin_unlock(spinlock_t *lock)
++{
++ /* NOTE: we always pass in '1' for nested, for simplicity */
++ spin_release(&lock->dep_map, 1, _RET_IP_);
++ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
++ migrate_enable();
++}
++EXPORT_SYMBOL(rt_spin_unlock);
++
++void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
++{
++ rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
++}
++EXPORT_SYMBOL(__rt_spin_unlock);
++
++/*
++ * Wait for the lock to get unlocked: instead of polling for an unlock
++ * (like raw spinlocks do), we lock and unlock, to force the kernel to
++ * schedule if there's contention:
++ */
++void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
++{
++ spin_lock(lock);
++ spin_unlock(lock);
++}
++EXPORT_SYMBOL(rt_spin_unlock_wait);
++
++int __lockfunc rt_spin_trylock(spinlock_t *lock)
++{
++ int ret;
++
++ migrate_disable();
++ ret = __rt_mutex_trylock(&lock->lock);
++ if (ret)
++ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
++ else
++ migrate_enable();
++ return ret;
++}
++EXPORT_SYMBOL(rt_spin_trylock);
++
++int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
++{
++ int ret;
++
++ local_bh_disable();
++ ret = __rt_mutex_trylock(&lock->lock);
++ if (ret) {
++ migrate_disable();
++ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
++ } else
++ local_bh_enable();
++ return ret;
++}
++EXPORT_SYMBOL(rt_spin_trylock_bh);
++
++int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
++{
++ int ret;
++
++ *flags = 0;
++ ret = __rt_mutex_trylock(&lock->lock);
++ if (ret) {
++ migrate_disable();
++ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
++ }
++ return ret;
++}
++EXPORT_SYMBOL(rt_spin_trylock_irqsave);
++
++int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
++{
++ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
++ if (atomic_add_unless(atomic, -1, 1))
++ return 0;
++ rt_spin_lock(lock);
++ if (atomic_dec_and_test(atomic))
++ return 1;
++ rt_spin_unlock(lock);
++ return 0;
++}
++EXPORT_SYMBOL(atomic_dec_and_spin_lock);
++
++void
++__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key)
++{
++#ifdef CONFIG_DEBUG_LOCK_ALLOC
++ /*
++ * Make sure we are not reinitializing a held lock:
++ */
++ debug_check_no_locks_freed((void *)lock, sizeof(*lock));
++ lockdep_init_map(&lock->dep_map, name, key, 0);
++#endif
++}
++EXPORT_SYMBOL(__rt_spin_lock_init);
++
++#endif /* PREEMPT_RT_FULL */
++
++static inline int
++try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
++ struct rt_mutex_waiter *waiter)
++{
++ return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
++}
++
+ /*
+ * Task blocks on lock.
+ *
+@@ -1051,6 +1390,7 @@ static int task_blocks_on_rt_mutex(struc
+ * Called with lock->wait_lock held and interrupts disabled.
+ */
+ static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
++ struct wake_q_head *wake_sleeper_q,
+ struct rt_mutex *lock)
+ {
+ struct rt_mutex_waiter *waiter;
+@@ -1090,7 +1430,10 @@ static void mark_wakeup_next_waiter(stru
+ * Pairs with preempt_enable() in rt_mutex_postunlock();
+ */
+ preempt_disable();
+- wake_q_add(wake_q, waiter->task);
++ if (waiter->savestate)
++ wake_q_add_sleeper(wake_sleeper_q, waiter->task);
++ else
++ wake_q_add(wake_q, waiter->task);
+ raw_spin_unlock(&current->pi_lock);
+ }
+
+@@ -1174,21 +1517,22 @@ void rt_mutex_adjust_pi(struct task_stru
+ return;
+ }
+ next_lock = waiter->lock;
+- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+ /* gets dropped in rt_mutex_adjust_prio_chain()! */
+ get_task_struct(task);
+
++ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
+ next_lock, NULL, task);
+ }
+
+-void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
++void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
+ {
+ debug_rt_mutex_init_waiter(waiter);
+ RB_CLEAR_NODE(&waiter->pi_tree_entry);
+ RB_CLEAR_NODE(&waiter->tree_entry);
+ waiter->task = NULL;
++ waiter->savestate = savestate;
+ }
+
+ /**
+@@ -1307,7 +1651,7 @@ rt_mutex_slowlock(struct rt_mutex *lock,
+ unsigned long flags;
+ int ret = 0;
+
+- rt_mutex_init_waiter(&waiter);
++ rt_mutex_init_waiter(&waiter, false);
+
+ /*
+ * Technically we could use raw_spin_[un]lock_irq() here, but this can
+@@ -1373,7 +1717,8 @@ static inline int rt_mutex_slowtrylock(s
+ * Return whether the current task needs to call rt_mutex_postunlock().
+ */
+ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
+- struct wake_q_head *wake_q)
++ struct wake_q_head *wake_q,
++ struct wake_q_head *wake_sleeper_q)
+ {
+ unsigned long flags;
+
+@@ -1427,7 +1772,7 @@ static bool __sched rt_mutex_slowunlock(
+ *
+ * Queue the next waiter for wakeup once we release the wait_lock.
+ */
+- mark_wakeup_next_waiter(wake_q, lock);
++ mark_wakeup_next_waiter(wake_q, wake_sleeper_q, lock);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+ return true; /* call rt_mutex_postunlock() */
+@@ -1479,9 +1824,11 @@ rt_mutex_fasttrylock(struct rt_mutex *lo
+ /*
+ * Performs the wakeup of the the top-waiter and re-enables preemption.
+ */
+-void rt_mutex_postunlock(struct wake_q_head *wake_q)
++void rt_mutex_postunlock(struct wake_q_head *wake_q,
++ struct wake_q_head *wake_sleeper_q)
+ {
+ wake_up_q(wake_q);
++ wake_up_q_sleeper(wake_sleeper_q);
+
+ /* Pairs with preempt_disable() in rt_mutex_slowunlock() */
+ preempt_enable();
+@@ -1490,15 +1837,17 @@ void rt_mutex_postunlock(struct wake_q_h
+ static inline void
+ rt_mutex_fastunlock(struct rt_mutex *lock,
+ bool (*slowfn)(struct rt_mutex *lock,
+- struct wake_q_head *wqh))
++ struct wake_q_head *wqh,
++ struct wake_q_head *wq_sleeper))
+ {
+ DEFINE_WAKE_Q(wake_q);
++ DEFINE_WAKE_Q(wake_sleeper_q);
+
+ if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
+ return;
+
+- if (slowfn(lock, &wake_q))
+- rt_mutex_postunlock(&wake_q);
++ if (slowfn(lock, &wake_q, &wake_sleeper_q))
++ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
+ }
+
+ int __sched __rt_mutex_lock_state(struct rt_mutex *lock, int state)
+@@ -1653,16 +2002,13 @@ void __sched __rt_mutex_unlock(struct rt
+ void __sched rt_mutex_unlock(struct rt_mutex *lock)
+ {
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+- rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
++ __rt_mutex_unlock(lock);
+ }
+ EXPORT_SYMBOL_GPL(rt_mutex_unlock);
+
+-/**
+- * Futex variant, that since futex variants do not use the fast-path, can be
+- * simple and will not need to retry.
+- */
+-bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
+- struct wake_q_head *wake_q)
++static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock,
++ struct wake_q_head *wake_q,
++ struct wake_q_head *wq_sleeper)
+ {
+ lockdep_assert_held(&lock->wait_lock);
+
+@@ -1679,22 +2025,34 @@ bool __sched __rt_mutex_futex_unlock(str
+ * avoid inversion prior to the wakeup. preempt_disable()
+ * therein pairs with rt_mutex_postunlock().
+ */
+- mark_wakeup_next_waiter(wake_q, lock);
++ mark_wakeup_next_waiter(wake_q, wq_sleeper, lock);
+
+ return true; /* call postunlock() */
+ }
+
++/**
++ * Futex variant, that since futex variants do not use the fast-path, can be
++ * simple and will not need to retry.
++ */
++bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock,
++ struct wake_q_head *wake_q,
++ struct wake_q_head *wq_sleeper)
++{
++ return __rt_mutex_unlock_common(lock, wake_q, wq_sleeper);
++}
++
+ void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
+ {
+ DEFINE_WAKE_Q(wake_q);
++ DEFINE_WAKE_Q(wake_sleeper_q);
+ bool postunlock;
+
+ raw_spin_lock_irq(&lock->wait_lock);
+- postunlock = __rt_mutex_futex_unlock(lock, &wake_q);
++ postunlock = __rt_mutex_futex_unlock(lock, &wake_q, &wake_sleeper_q);
+ raw_spin_unlock_irq(&lock->wait_lock);
+
+ if (postunlock)
+- rt_mutex_postunlock(&wake_q);
++ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
+ }
+
+ /**
+@@ -1734,7 +2092,7 @@ void __rt_mutex_init(struct rt_mutex *lo
+ if (name && key)
+ debug_rt_mutex_init(lock, name, key);
+ }
+-EXPORT_SYMBOL_GPL(__rt_mutex_init);
++EXPORT_SYMBOL(__rt_mutex_init);
+
+ /**
+ * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
+@@ -1903,6 +2261,7 @@ int rt_mutex_wait_proxy_lock(struct rt_m
+ struct hrtimer_sleeper *to,
+ struct rt_mutex_waiter *waiter)
+ {
++ struct task_struct *tsk = current;
+ int ret;
+
+ raw_spin_lock_irq(&lock->wait_lock);
+@@ -1914,6 +2273,24 @@ int rt_mutex_wait_proxy_lock(struct rt_m
+ * have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
++ /*
++ * RT has a problem here when the wait got interrupted by a timeout
++ * or a signal. task->pi_blocked_on is still set. The task must
++ * acquire the hash bucket lock when returning from this function.
++ *
++ * If the hash bucket lock is contended then the
++ * BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)) in
++ * task_blocks_on_rt_mutex() will trigger. This can be avoided by
++ * clearing task->pi_blocked_on which removes the task from the
++ * boosting chain of the rtmutex. That's correct because the task
++ * is not longer blocked on it.
++ */
++ if (ret) {
++ raw_spin_lock(&tsk->pi_lock);
++ tsk->pi_blocked_on = NULL;
++ raw_spin_unlock(&tsk->pi_lock);
++ }
++
+ raw_spin_unlock_irq(&lock->wait_lock);
+
+ return ret;
+--- a/kernel/locking/rtmutex_common.h
++++ b/kernel/locking/rtmutex_common.h
+@@ -14,6 +14,7 @@
+
+ #include <linux/rtmutex.h>
+ #include <linux/sched/wake_q.h>
++#include <linux/sched/debug.h>
+
+ /*
+ * This is the control structure for tasks blocked on a rt_mutex,
+@@ -28,6 +29,7 @@ struct rt_mutex_waiter {
+ struct rb_node pi_tree_entry;
+ struct task_struct *task;
+ struct rt_mutex *lock;
++ bool savestate;
+ #ifdef CONFIG_DEBUG_RT_MUTEXES
+ unsigned long ip;
+ struct pid *deadlock_task_pid;
+@@ -107,7 +109,7 @@ extern void rt_mutex_init_proxy_locked(s
+ struct task_struct *proxy_owner);
+ extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
+ struct task_struct *proxy_owner);
+-extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
++extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savetate);
+ extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task);
+@@ -124,9 +126,12 @@ extern int rt_mutex_futex_trylock(struct
+
+ extern void rt_mutex_futex_unlock(struct rt_mutex *lock);
+ extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
+- struct wake_q_head *wqh);
++ struct wake_q_head *wqh,
++ struct wake_q_head *wq_sleeper);
++
++extern void rt_mutex_postunlock(struct wake_q_head *wake_q,
++ struct wake_q_head *wake_sleeper_q);
+
+-extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
+ /* RW semaphore special interface */
+
+ extern int __rt_mutex_lock_state(struct rt_mutex *lock, int state);
+@@ -136,6 +141,10 @@ int __sched rt_mutex_slowlock_locked(str
+ struct hrtimer_sleeper *timeout,
+ enum rtmutex_chainwalk chwalk,
+ struct rt_mutex_waiter *waiter);
++void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
++ struct rt_mutex_waiter *waiter,
++ unsigned long flags);
++void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock);
+
+ #ifdef CONFIG_DEBUG_RT_MUTEXES
+ # include "rtmutex-debug.h"
+--- a/kernel/sched/core.c
++++ b/kernel/sched/core.c
+@@ -427,9 +427,15 @@ static bool set_nr_if_polling(struct tas
+ #endif
+ #endif
+
+-void wake_q_add(struct wake_q_head *head, struct task_struct *task)
++void __wake_q_add(struct wake_q_head *head, struct task_struct *task,
++ bool sleeper)
+ {
+- struct wake_q_node *node = &task->wake_q;
++ struct wake_q_node *node;
++
++ if (sleeper)
++ node = &task->wake_q_sleeper;
++ else
++ node = &task->wake_q;
+
+ /*
+ * Atomically grab the task, if ->wake_q is !nil already it means
+@@ -451,24 +457,32 @@ void wake_q_add(struct wake_q_head *head
+ head->lastp = &node->next;
+ }
+
+-void wake_up_q(struct wake_q_head *head)
++void __wake_up_q(struct wake_q_head *head, bool sleeper)
+ {
+ struct wake_q_node *node = head->first;
+
+ while (node != WAKE_Q_TAIL) {
+ struct task_struct *task;
+
+- task = container_of(node, struct task_struct, wake_q);
++ if (sleeper)
++ task = container_of(node, struct task_struct, wake_q_sleeper);
++ else
++ task = container_of(node, struct task_struct, wake_q);
+ BUG_ON(!task);
+ /* Task can safely be re-inserted now: */
+ node = node->next;
+- task->wake_q.next = NULL;
+-
++ if (sleeper)
++ task->wake_q_sleeper.next = NULL;
++ else
++ task->wake_q.next = NULL;
+ /*
+ * wake_up_process() implies a wmb() to pair with the queueing
+ * in wake_q_add() so as not to miss wakeups.
+ */
+- wake_up_process(task);
++ if (sleeper)
++ wake_up_lock_sleeper(task);
++ else
++ wake_up_process(task);
+ put_task_struct(task);
+ }
+ }