tools/lib/lockdep: drop liblockdep

TL;DR: While a tool like liblockdep is useful, it probably doesn't
belong within the kernel tree.

liblockdep attempts to reuse kernel code both directly (by directly
building the kernel's lockdep code) as well as indirectly (by using
sanitized headers). This makes liblockdep an integral part of the
kernel.

It also makes liblockdep quite unique: while other userspace code might
use sanitized headers, it generally doesn't attempt to use kernel code
directly which means that changes on the kernel side of things don't
affect (and break) it directly.

All our workflows and tooling around liblockdep don't support this
uniqueness. Changes that go into the kernel code aren't validated to not
break in-tree userspace code.

liblockdep ended up being very fragile, breaking over and over, to the
point that living in the same tree as the lockdep code lost most of it's
value.

liblockdep should continue living in an external tree, syncing with
the kernel often, in a controllable way.

Signed-off-by: Sasha Levin <sashal@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 0 insertions, 214 deletions

diff --git a/tools/lib/lockdep/include/liblockdep/common.h b/tools/lib/lockdep/include/liblockdep/common.h
deleted file mode 100644
index a6d7ee5f18ba..000000000000
--- a/tools/lib/lockdep/include/liblockdep/common.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LIBLOCKDEP_COMMON_H
-#define _LIBLOCKDEP_COMMON_H
-
-#include <pthread.h>
-
-#define NR_LOCKDEP_CACHING_CLASSES 2
-#define MAX_LOCKDEP_SUBCLASSES 8UL
-
-#ifndef CALLER_ADDR0
-#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
-#endif
-
-#ifndef _RET_IP_
-#define _RET_IP_ CALLER_ADDR0
-#endif
-
-#ifndef _THIS_IP_
-#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
-#endif
-
-struct lockdep_subclass_key {
-	char __one_byte;
-};
-
-struct lock_class_key {
-	struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
-};
-
-struct lockdep_map {
-	struct lock_class_key	*key;
-	struct lock_class	*class_cache[NR_LOCKDEP_CACHING_CLASSES];
-	const char		*name;
-#ifdef CONFIG_LOCK_STAT
-	int			cpu;
-	unsigned long		ip;
-#endif
-};
-
-void lockdep_init_map(struct lockdep_map *lock, const char *name,
-			struct lock_class_key *key, int subclass);
-void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
-			int trylock, int read, int check,
-			struct lockdep_map *nest_lock, unsigned long ip);
-void lock_release(struct lockdep_map *lock, unsigned long ip);
-void lockdep_reset_lock(struct lockdep_map *lock);
-void lockdep_register_key(struct lock_class_key *key);
-void lockdep_unregister_key(struct lock_class_key *key);
-extern void debug_check_no_locks_freed(const void *from, unsigned long len);
-
-#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
-	{ .name = (_name), .key = (void *)(_key), }
-
-#endif
diff --git a/tools/lib/lockdep/include/liblockdep/mutex.h b/tools/lib/lockdep/include/liblockdep/mutex.h
deleted file mode 100644
index bd106b82759b..000000000000
--- a/tools/lib/lockdep/include/liblockdep/mutex.h
+++ /dev/null
@@ -1,73 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LIBLOCKDEP_MUTEX_H
-#define _LIBLOCKDEP_MUTEX_H
-
-#include <pthread.h>
-#include "common.h"
-
-struct liblockdep_pthread_mutex {
-	pthread_mutex_t mutex;
-	struct lock_class_key key;
-	struct lockdep_map dep_map;
-};
-
-typedef struct liblockdep_pthread_mutex liblockdep_pthread_mutex_t;
-
-#define LIBLOCKDEP_PTHREAD_MUTEX_INITIALIZER(mtx)			\
-		(const struct liblockdep_pthread_mutex) {		\
-	.mutex = PTHREAD_MUTEX_INITIALIZER,				\
-	.dep_map = STATIC_LOCKDEP_MAP_INIT(#mtx, &((&(mtx))->dep_map)),	\
-}
-
-static inline int __mutex_init(liblockdep_pthread_mutex_t *lock,
-				const char *name,
-				struct lock_class_key *key,
-				const pthread_mutexattr_t *__mutexattr)
-{
-	lockdep_init_map(&lock->dep_map, name, key, 0);
-	return pthread_mutex_init(&lock->mutex, __mutexattr);
-}
-
-#define liblockdep_pthread_mutex_init(mutex, mutexattr)			\
-({									\
-	lockdep_register_key(&(mutex)->key);				\
-	__mutex_init((mutex), #mutex, &(mutex)->key, (mutexattr));	\
-})
-
-static inline int liblockdep_pthread_mutex_lock(liblockdep_pthread_mutex_t *lock)
-{
-	lock_acquire(&lock->dep_map, 0, 0, 0, 1, NULL, (unsigned long)_RET_IP_);
-	return pthread_mutex_lock(&lock->mutex);
-}
-
-static inline int liblockdep_pthread_mutex_unlock(liblockdep_pthread_mutex_t *lock)
-{
-	lock_release(&lock->dep_map, (unsigned long)_RET_IP_);
-	return pthread_mutex_unlock(&lock->mutex);
-}
-
-static inline int liblockdep_pthread_mutex_trylock(liblockdep_pthread_mutex_t *lock)
-{
-	lock_acquire(&lock->dep_map, 0, 1, 0, 1, NULL, (unsigned long)_RET_IP_);
-	return pthread_mutex_trylock(&lock->mutex) == 0 ? 1 : 0;
-}
-
-static inline int liblockdep_pthread_mutex_destroy(liblockdep_pthread_mutex_t *lock)
-{
-	lockdep_reset_lock(&lock->dep_map);
-	lockdep_unregister_key(&lock->key);
-	return pthread_mutex_destroy(&lock->mutex);
-}
-
-#ifdef __USE_LIBLOCKDEP
-
-#define pthread_mutex_t         liblockdep_pthread_mutex_t
-#define pthread_mutex_init      liblockdep_pthread_mutex_init
-#define pthread_mutex_lock      liblockdep_pthread_mutex_lock
-#define pthread_mutex_unlock    liblockdep_pthread_mutex_unlock
-#define pthread_mutex_trylock   liblockdep_pthread_mutex_trylock
-#define pthread_mutex_destroy   liblockdep_pthread_mutex_destroy
-
-#endif
-
-#endif
diff --git a/tools/lib/lockdep/include/liblockdep/rwlock.h b/tools/lib/lockdep/include/liblockdep/rwlock.h
deleted file mode 100644
index 6d5d2932bf4d..000000000000
--- a/tools/lib/lockdep/include/liblockdep/rwlock.h
+++ /dev/null
@@ -1,87 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LIBLOCKDEP_RWLOCK_H
-#define _LIBLOCKDEP_RWLOCK_H
-
-#include <pthread.h>
-#include "common.h"
-
-struct liblockdep_pthread_rwlock {
-	pthread_rwlock_t rwlock;
-	struct lockdep_map dep_map;
-};
-
-typedef struct liblockdep_pthread_rwlock liblockdep_pthread_rwlock_t;
-
-#define LIBLOCKDEP_PTHREAD_RWLOCK_INITIALIZER(rwl)			\
-		(struct liblockdep_pthread_rwlock) {			\
-	.rwlock = PTHREAD_RWLOCK_INITIALIZER,				\
-	.dep_map = STATIC_LOCKDEP_MAP_INIT(#rwl, &((&(rwl))->dep_map)),	\
-}
-
-static inline int __rwlock_init(liblockdep_pthread_rwlock_t *lock,
-				const char *name,
-				struct lock_class_key *key,
-				const pthread_rwlockattr_t *attr)
-{
-	lockdep_init_map(&lock->dep_map, name, key, 0);
-
-	return pthread_rwlock_init(&lock->rwlock, attr);
-}
-
-#define liblockdep_pthread_rwlock_init(lock, attr)		\
-({							\
-	static struct lock_class_key __key;		\
-							\
-	__rwlock_init((lock), #lock, &__key, (attr));	\
-})
-
-static inline int liblockdep_pthread_rwlock_rdlock(liblockdep_pthread_rwlock_t *lock)
-{
-	lock_acquire(&lock->dep_map, 0, 0, 2, 1, NULL, (unsigned long)_RET_IP_);
-	return pthread_rwlock_rdlock(&lock->rwlock);
-
-}
-
-static inline int liblockdep_pthread_rwlock_unlock(liblockdep_pthread_rwlock_t *lock)
-{
-	lock_release(&lock->dep_map, (unsigned long)_RET_IP_);
-	return pthread_rwlock_unlock(&lock->rwlock);
-}
-
-static inline int liblockdep_pthread_rwlock_wrlock(liblockdep_pthread_rwlock_t *lock)
-{
-	lock_acquire(&lock->dep_map, 0, 0, 0, 1, NULL, (unsigned long)_RET_IP_);
-	return pthread_rwlock_wrlock(&lock->rwlock);
-}
-
-static inline int liblockdep_pthread_rwlock_tryrdlock(liblockdep_pthread_rwlock_t *lock)
-{
-	lock_acquire(&lock->dep_map, 0, 1, 2, 1, NULL, (unsigned long)_RET_IP_);
-	return pthread_rwlock_tryrdlock(&lock->rwlock) == 0 ? 1 : 0;
-}
-
-static inline int liblockdep_pthread_rwlock_trywrlock(liblockdep_pthread_rwlock_t *lock)
-{
-	lock_acquire(&lock->dep_map, 0, 1, 0, 1, NULL, (unsigned long)_RET_IP_);
-	return pthread_rwlock_trywrlock(&lock->rwlock) == 0 ? 1 : 0;
-}
-
-static inline int liblockdep_rwlock_destroy(liblockdep_pthread_rwlock_t *lock)
-{
-	return pthread_rwlock_destroy(&lock->rwlock);
-}
-
-#ifdef __USE_LIBLOCKDEP
-
-#define pthread_rwlock_t		liblockdep_pthread_rwlock_t
-#define pthread_rwlock_init		liblockdep_pthread_rwlock_init
-#define pthread_rwlock_rdlock		liblockdep_pthread_rwlock_rdlock
-#define pthread_rwlock_unlock		liblockdep_pthread_rwlock_unlock
-#define pthread_rwlock_wrlock		liblockdep_pthread_rwlock_wrlock
-#define pthread_rwlock_tryrdlock	liblockdep_pthread_rwlock_tryrdlock
-#define pthread_rwlock_trywrlock	liblockdep_pthread_rwlock_trywrlock
-#define pthread_rwlock_destroy		liblockdep_rwlock_destroy
-
-#endif
-
-#endif