Merge tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:

 - rtmutex cleanup & spring cleaning pass that removes ~400 lines of
   code

 - Futex simplifications & cleanups

 - Add debugging to the CSD code, to help track down a tenacious race
   (or hw problem)

 - Add lockdep_assert_not_held(), to allow code to require a lock to not
   be held, and propagate this into the ath10k driver

 - Misc LKMM documentation updates

 - Misc KCSAN updates: cleanups & documentation updates

 - Misc fixes and cleanups

 - Fix locktorture bugs with ww_mutexes

* tag 'locking-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  kcsan: Fix printk format string
  static_call: Relax static_call_update() function argument type
  static_call: Fix unused variable warn w/o MODULE
  locking/rtmutex: Clean up signal handling in __rt_mutex_slowlock()
  locking/rtmutex: Restrict the trylock WARN_ON() to debug
  locking/rtmutex: Fix misleading comment in rt_mutex_postunlock()
  locking/rtmutex: Consolidate the fast/slowpath invocation
  locking/rtmutex: Make text section and inlining consistent
  locking/rtmutex: Move debug functions as inlines into common header
  locking/rtmutex: Decrapify __rt_mutex_init()
  locking/rtmutex: Remove pointless CONFIG_RT_MUTEXES=n stubs
  locking/rtmutex: Inline chainwalk depth check
  locking/rtmutex: Move rt_mutex_debug_task_free() to rtmutex.c
  locking/rtmutex: Remove empty and unused debug stubs
  locking/rtmutex: Consolidate rt_mutex_init()
  locking/rtmutex: Remove output from deadlock detector
  locking/rtmutex: Remove rtmutex deadlock tester leftovers
  locking/rtmutex: Remove rt_mutex_timed_lock()
  MAINTAINERS: Add myself as futex reviewer
  locking/mutex: Remove repeated declaration
  ...

8 files changed, 38 insertions, 57 deletions

diff --git a/include/linux/kcsan-checks.h b/include/linux/kcsan-checks.h
index cf14840609ce..9fd0ad80fef6 100644
--- a/include/linux/kcsan-checks.h
+++ b/include/linux/kcsan-checks.h
@@ -1,4 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KCSAN access checks and modifiers. These can be used to explicitly check
+ * uninstrumented accesses, or change KCSAN checking behaviour of accesses.
+ *
+ * Copyright (C) 2019, Google LLC.
+ */
 
 #ifndef _LINUX_KCSAN_CHECKS_H
 #define _LINUX_KCSAN_CHECKS_H
diff --git a/include/linux/kcsan.h b/include/linux/kcsan.h
index 53340d8789f9..fc266ecb2a4d 100644
--- a/include/linux/kcsan.h
+++ b/include/linux/kcsan.h
@@ -1,4 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. Public interface and
+ * data structures to set up runtime. See kcsan-checks.h for explicit checks and
+ * modifiers. For more info please see Documentation/dev-tools/kcsan.rst.
+ *
+ * Copyright (C) 2019, Google LLC.
+ */
 
 #ifndef _LINUX_KCSAN_H
 #define _LINUX_KCSAN_H
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 1c746139d5e3..5cf387813754 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -155,7 +155,7 @@ extern void lockdep_set_selftest_task(struct task_struct *task);
 extern void lockdep_init_task(struct task_struct *task);
 
 /*
- * Split the recrursion counter in two to readily detect 'off' vs recursion.
+ * Split the recursion counter in two to readily detect 'off' vs recursion.
  */
 #define LOCKDEP_RECURSION_BITS	16
 #define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)
@@ -268,6 +268,11 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 
 extern void lock_release(struct lockdep_map *lock, unsigned long ip);
 
+/* lock_is_held_type() returns */
+#define LOCK_STATE_UNKNOWN	-1
+#define LOCK_STATE_NOT_HELD	0
+#define LOCK_STATE_HELD		1
+
 /*
  * Same "read" as for lock_acquire(), except -1 means any.
  */
@@ -301,8 +306,14 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
 
 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
 
-#define lockdep_assert_held(l)	do {				\
-		WARN_ON(debug_locks && !lockdep_is_held(l));	\
+#define lockdep_assert_held(l)	do {					\
+		WARN_ON(debug_locks &&					\
+			lockdep_is_held(l) == LOCK_STATE_NOT_HELD);	\
+	} while (0)
+
+#define lockdep_assert_not_held(l)	do {				\
+		WARN_ON(debug_locks &&					\
+			lockdep_is_held(l) == LOCK_STATE_HELD);		\
 	} while (0)
 
 #define lockdep_assert_held_write(l)	do {			\
@@ -397,7 +408,8 @@ extern int lockdep_is_held(const void *);
 #define lockdep_is_held_type(l, r)		(1)
 
 #define lockdep_assert_held(l)			do { (void)(l); } while (0)
-#define lockdep_assert_held_write(l)	do { (void)(l); } while (0)
+#define lockdep_assert_not_held(l)		do { (void)(l); } while (0)
+#define lockdep_assert_held_write(l)		do { (void)(l); } while (0)
 #define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
 #define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
 #define lockdep_assert_none_held_once()	do { } while (0)
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 515cff77a4f4..e19323521f9c 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -20,6 +20,7 @@
 #include <linux/osq_lock.h>
 #include <linux/debug_locks.h>
 
+struct ww_class;
 struct ww_acquire_ctx;
 
 /*
@@ -65,9 +66,6 @@ struct mutex {
 #endif
 };
 
-struct ww_class;
-struct ww_acquire_ctx;
-
 struct ww_mutex {
 	struct mutex base;
 	struct ww_acquire_ctx *ctx;
diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index 6fd615a0eea9..d1672de9ca89 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -31,12 +31,6 @@ struct rt_mutex {
 	raw_spinlock_t		wait_lock;
 	struct rb_root_cached   waiters;
 	struct task_struct	*owner;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-	int			save_state;
-	const char		*name, *file;
-	int			line;
-	void			*magic;
-#endif
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lockdep_map	dep_map;
 #endif
@@ -46,35 +40,17 @@ struct rt_mutex_waiter;
 struct hrtimer_sleeper;
 
 #ifdef CONFIG_DEBUG_RT_MUTEXES
- extern int rt_mutex_debug_check_no_locks_freed(const void *from,
-						unsigned long len);
- extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
+extern void rt_mutex_debug_task_free(struct task_struct *tsk);
 #else
- static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
-						       unsigned long len)
- {
-	return 0;
- }
-# define rt_mutex_debug_check_no_locks_held(task)	do { } while (0)
+static inline void rt_mutex_debug_task_free(struct task_struct *tsk) { }
 #endif
 
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
-	, .name = #mutexname, .file = __FILE__, .line = __LINE__
-
-# define rt_mutex_init(mutex) \
+#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, 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 }
@@ -86,7 +62,6 @@ do { \
 	{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
 	, .waiters = RB_ROOT_CACHED \
 	, .owner = NULL \
-	__DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
 	__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
 
 #define DEFINE_RT_MUTEX(mutexname) \
@@ -104,7 +79,6 @@ static inline int rt_mutex_is_locked(struct rt_mutex *lock)
 }
 
 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);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
@@ -115,9 +89,6 @@ extern void rt_mutex_lock(struct rt_mutex *lock);
 #endif
 
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
-extern int rt_mutex_timed_lock(struct rt_mutex *lock,
-			       struct hrtimer_sleeper *timeout);
-
 extern int rt_mutex_trylock(struct rt_mutex *lock);
 
 extern void rt_mutex_unlock(struct rt_mutex *lock);
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 4c715be48717..a66038d88878 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -110,7 +110,7 @@ do {								\
 
 /*
  * This is the same regardless of which rwsem implementation that is being used.
- * It is just a heuristic meant to be called by somebody alreadying holding the
+ * It is just a heuristic meant to be called by somebody already holding the
  * rwsem to see if somebody from an incompatible type is wanting access to the
  * lock.
  */
diff --git a/include/linux/static_call.h b/include/linux/static_call.h
index e01b61ab86b1..fc94faa53b5b 100644
--- a/include/linux/static_call.h
+++ b/include/linux/static_call.h
@@ -118,9 +118,9 @@ extern void arch_static_call_transform(void *site, void *tramp, void *func, bool
 
 #define static_call_update(name, func)					\
 ({									\
-	BUILD_BUG_ON(!__same_type(*(func), STATIC_CALL_TRAMP(name)));	\
+	typeof(&STATIC_CALL_TRAMP(name)) __F = (func);			\
 	__static_call_update(&STATIC_CALL_KEY(name),			\
-			     STATIC_CALL_TRAMP_ADDR(name), func);	\
+			     STATIC_CALL_TRAMP_ADDR(name), __F);	\
 })
 
 #define static_call_query(name) (READ_ONCE(STATIC_CALL_KEY(name).func))
diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
index 6ecf2a0220db..b77f39f319ad 100644
--- a/include/linux/ww_mutex.h
+++ b/include/linux/ww_mutex.h
@@ -48,39 +48,26 @@ struct ww_acquire_ctx {
 #endif
 };
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __WW_CLASS_MUTEX_INITIALIZER(lockname, class) \
-		, .ww_class = class
-#else
-# define __WW_CLASS_MUTEX_INITIALIZER(lockname, class)
-#endif
-
 #define __WW_CLASS_INITIALIZER(ww_class, _is_wait_die)	    \
 		{ .stamp = ATOMIC_LONG_INIT(0) \
 		, .acquire_name = #ww_class "_acquire" \
 		, .mutex_name = #ww_class "_mutex" \
 		, .is_wait_die = _is_wait_die }
 
-#define __WW_MUTEX_INITIALIZER(lockname, class) \
-		{ .base =  __MUTEX_INITIALIZER(lockname.base) \
-		__WW_CLASS_MUTEX_INITIALIZER(lockname, class) }
-
 #define DEFINE_WD_CLASS(classname) \
 	struct ww_class classname = __WW_CLASS_INITIALIZER(classname, 1)
 
 #define DEFINE_WW_CLASS(classname) \
 	struct ww_class classname = __WW_CLASS_INITIALIZER(classname, 0)
 
-#define DEFINE_WW_MUTEX(mutexname, ww_class) \
-	struct ww_mutex mutexname = __WW_MUTEX_INITIALIZER(mutexname, ww_class)
-
 /**
  * ww_mutex_init - initialize the w/w mutex
  * @lock: the mutex to be initialized
  * @ww_class: the w/w class the mutex should belong to
  *
  * Initialize the w/w mutex to unlocked state and associate it with the given
- * class.
+ * class. Static define macro for w/w mutex is not provided and this function
+ * is the only way to properly initialize the w/w mutex.
  *
  * It is not allowed to initialize an already locked mutex.
  */