kernel/locking/spinlock_debug.c

17 void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
22 	 * Make sure we are not reinitializing a held lock:
24 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
25 	lockdep_init_map_wait(&lock->dep_map, name, key, 0, inner);
27 	lock->raw_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
28 	lock->magic = SPINLOCK_MAGIC;
29 	lock->owner = SPINLOCK_OWNER_INIT;
30 	lock->owner_cpu = -1;
36 void __rwlock_init(rwlock_t *lock, const char *name,
41 	 * Make sure we are not reinitializing a held lock:
43 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
44 	lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_CONFIG);
46 	lock->raw_lock = (arch_rwlock_t) __ARCH_RW_LOCK_UNLOCKED;
47 	lock->magic = RWLOCK_MAGIC;
48 	lock->owner = SPINLOCK_OWNER_INIT;
49 	lock->owner_cpu = -1;
55 static void spin_dump(raw_spinlock_t *lock, const char *msg)
57 	struct task_struct *owner = READ_ONCE(lock->owner);
64 	printk(KERN_EMERG " lock: %pS, .magic: %08x, .owner: %s/%d, "
66 		lock, READ_ONCE(lock->magic),
69 		READ_ONCE(lock->owner_cpu));
73 static void spin_bug(raw_spinlock_t *lock, const char *msg)
78 	spin_dump(lock, msg);
81 #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)
84 debug_spin_lock_before(raw_spinlock_t *lock)
86 	SPIN_BUG_ON(READ_ONCE(lock->magic) != SPINLOCK_MAGIC, lock, "bad magic");
87 	SPIN_BUG_ON(READ_ONCE(lock->owner) == current, lock, "recursion");
88 	SPIN_BUG_ON(READ_ONCE(lock->owner_cpu) == raw_smp_processor_id(),
89 							lock, "cpu recursion");
92 static inline void debug_spin_lock_after(raw_spinlock_t *lock)
94 	WRITE_ONCE(lock->owner_cpu, raw_smp_processor_id());
95 	WRITE_ONCE(lock->owner, current);
98 static inline void debug_spin_unlock(raw_spinlock_t *lock)
100 	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
101 	SPIN_BUG_ON(!raw_spin_is_locked(lock), lock, "already unlocked");
102 	SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
103 	SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
104 							lock, "wrong CPU");
105 	WRITE_ONCE(lock->owner, SPINLOCK_OWNER_INIT);
106 	WRITE_ONCE(lock->owner_cpu, -1);
111  * the detection here with an unfair lock which can cause problem of its own.
113 void do_raw_spin_lock(raw_spinlock_t *lock)
115 	debug_spin_lock_before(lock);
116 	arch_spin_lock(&lock->raw_lock);
118 	debug_spin_lock_after(lock);
121 int do_raw_spin_trylock(raw_spinlock_t *lock)
123 	int ret = arch_spin_trylock(&lock->raw_lock);
127 		debug_spin_lock_after(lock);
133 	SPIN_BUG_ON(!ret, lock, "trylock failure on UP");
138 void do_raw_spin_unlock(raw_spinlock_t *lock)
141 	debug_spin_unlock(lock);
142 	arch_spin_unlock(&lock->raw_lock);
146 static void rwlock_bug(rwlock_t *lock, const char *msg)
153 		task_pid_nr(current), lock);
157 #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)
159 void do_raw_read_lock(rwlock_t *lock)
161 	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
162 	arch_read_lock(&lock->raw_lock);
165 int do_raw_read_trylock(rwlock_t *lock)
167 	int ret = arch_read_trylock(&lock->raw_lock);
173 	RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
178 void do_raw_read_unlock(rwlock_t *lock)
180 	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
181 	arch_read_unlock(&lock->raw_lock);
184 static inline void debug_write_lock_before(rwlock_t *lock)
186 	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
187 	RWLOCK_BUG_ON(lock->owner == current, lock, "recursion");
188 	RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
189 							lock, "cpu recursion");
192 static inline void debug_write_lock_after(rwlock_t *lock)
194 	WRITE_ONCE(lock->owner_cpu, raw_smp_processor_id());
195 	WRITE_ONCE(lock->owner, current);
198 static inline void debug_write_unlock(rwlock_t *lock)
200 	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
201 	RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
202 	RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
203 							lock, "wrong CPU");
204 	WRITE_ONCE(lock->owner, SPINLOCK_OWNER_INIT);
205 	WRITE_ONCE(lock->owner_cpu, -1);
208 void do_raw_write_lock(rwlock_t *lock)
210 	debug_write_lock_before(lock);
211 	arch_write_lock(&lock->raw_lock);
212 	debug_write_lock_after(lock);
215 int do_raw_write_trylock(rwlock_t *lock)
217 	int ret = arch_write_trylock(&lock->raw_lock);
220 		debug_write_lock_after(lock);
225 	RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
230 void do_raw_write_unlock(rwlock_t *lock)
232 	debug_write_unlock(lock);
233 	arch_write_unlock(&lock->raw_lock);