diff options
Diffstat (limited to 'lib/spinlock_debug.c')
| -rw-r--r-- | lib/spinlock_debug.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c new file mode 100644 index 00000000000..906ad101eab --- /dev/null +++ b/lib/spinlock_debug.c @@ -0,0 +1,257 @@ +/* + * Copyright 2005, Red Hat, Inc., Ingo Molnar + * Released under the General Public License (GPL). + * + * This file contains the spinlock/rwlock implementations for + * DEBUG_SPINLOCK. + */ + +#include <linux/config.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/delay.h> + +static void spin_bug(spinlock_t *lock, const char *msg) +{ + static long print_once = 1; + struct task_struct *owner = NULL; + + if (xchg(&print_once, 0)) { + if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) + owner = lock->owner; + printk("BUG: spinlock %s on CPU#%d, %s/%d\n", + msg, smp_processor_id(), current->comm, current->pid); + printk(" lock: %p, .magic: %08x, .owner: %s/%d, .owner_cpu: %d\n", + lock, lock->magic, + owner ? owner->comm : "<none>", + owner ? owner->pid : -1, + lock->owner_cpu); + dump_stack(); +#ifdef CONFIG_SMP + /* + * We cannot continue on SMP: + */ +// panic("bad locking"); +#endif + } +} + +#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) + +static inline void debug_spin_lock_before(spinlock_t *lock) +{ + SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); + SPIN_BUG_ON(lock->owner == current, lock, "recursion"); + SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), + lock, "cpu recursion"); +} + +static inline void debug_spin_lock_after(spinlock_t *lock) +{ + lock->owner_cpu = raw_smp_processor_id(); + lock->owner = current; +} + +static inline void debug_spin_unlock(spinlock_t *lock) +{ + SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); + SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked"); + SPIN_BUG_ON(lock->owner != current, lock, "wrong owner"); + SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), + lock, "wrong CPU"); + lock->owner = SPINLOCK_OWNER_INIT; + lock->owner_cpu = -1; +} + +static void __spin_lock_debug(spinlock_t *lock) +{ + int print_once = 1; + u64 i; + + for (;;) { + for (i = 0; i < loops_per_jiffy * HZ; i++) { + cpu_relax(); + if (__raw_spin_trylock(&lock->raw_lock)) + return; + } + /* lockup suspected: */ + if (print_once) { + print_once = 0; + printk("BUG: spinlock lockup on CPU#%d, %s/%d, %p\n", + smp_processor_id(), current->comm, current->pid, + lock); + dump_stack(); + } + } +} + +void _raw_spin_lock(spinlock_t *lock) +{ + debug_spin_lock_before(lock); + if (unlikely(!__raw_spin_trylock(&lock->raw_lock))) + __spin_lock_debug(lock); + debug_spin_lock_after(lock); +} + +int _raw_spin_trylock(spinlock_t *lock) +{ + int ret = __raw_spin_trylock(&lock->raw_lock); + + if (ret) + debug_spin_lock_after(lock); +#ifndef CONFIG_SMP + /* + * Must not happen on UP: + */ + SPIN_BUG_ON(!ret, lock, "trylock failure on UP"); +#endif + return ret; +} + +void _raw_spin_unlock(spinlock_t *lock) +{ + debug_spin_unlock(lock); + __raw_spin_unlock(&lock->raw_lock); +} + +static void rwlock_bug(rwlock_t *lock, const char *msg) +{ + static long print_once = 1; + + if (xchg(&print_once, 0)) { + printk("BUG: rwlock %s on CPU#%d, %s/%d, %p\n", msg, + smp_processor_id(), current->comm, current->pid, lock); + dump_stack(); +#ifdef CONFIG_SMP + /* + * We cannot continue on SMP: + */ + panic("bad locking"); +#endif + } +} + +#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) + +static void __read_lock_debug(rwlock_t *lock) +{ + int print_once = 1; + u64 i; + + for (;;) { + for (i = 0; i < loops_per_jiffy * HZ; i++) { + cpu_relax(); + if (__raw_read_trylock(&lock->raw_lock)) + return; + } + /* lockup suspected: */ + if (print_once) { + print_once = 0; + printk("BUG: read-lock lockup on CPU#%d, %s/%d, %p\n", + smp_processor_id(), current->comm, current->pid, + lock); + dump_stack(); + } + } +} + +void _raw_read_lock(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + if (unlikely(!__raw_read_trylock(&lock->raw_lock))) + __read_lock_debug(lock); +} + +int _raw_read_trylock(rwlock_t *lock) +{ + int ret = __raw_read_trylock(&lock->raw_lock); + +#ifndef CONFIG_SMP + /* + * Must not happen on UP: + */ + RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); +#endif + return ret; +} + +void _raw_read_unlock(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + __raw_read_unlock(&lock->raw_lock); +} + +static inline void debug_write_lock_before(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); + RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), + lock, "cpu recursion"); +} + +static inline void debug_write_lock_after(rwlock_t *lock) +{ + lock->owner_cpu = raw_smp_processor_id(); + lock->owner = current; +} + +static inline void debug_write_unlock(rwlock_t *lock) +{ + RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); + RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner"); + RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), + lock, "wrong CPU"); + lock->owner = SPINLOCK_OWNER_INIT; + lock->owner_cpu = -1; +} + +static void __write_lock_debug(rwlock_t *lock) +{ + int print_once = 1; + u64 i; + + for (;;) { + for (i = 0; i < loops_per_jiffy * HZ; i++) { + cpu_relax(); + if (__raw_write_trylock(&lock->raw_lock)) + return; + } + /* lockup suspected: */ + if (print_once) { + print_once = 0; + printk("BUG: write-lock lockup on CPU#%d, %s/%d, %p\n", + smp_processor_id(), current->comm, current->pid, + lock); + dump_stack(); + } + } +} + +void _raw_write_lock(rwlock_t *lock) +{ + debug_write_lock_before(lock); + if (unlikely(!__raw_write_trylock(&lock->raw_lock))) + __write_lock_debug(lock); + debug_write_lock_after(lock); +} + +int _raw_write_trylock(rwlock_t *lock) +{ + int ret = __raw_write_trylock(&lock->raw_lock); + + if (ret) + debug_write_lock_after(lock); +#ifndef CONFIG_SMP + /* + * Must not happen on UP: + */ + RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); +#endif + return ret; +} + +void _raw_write_unlock(rwlock_t *lock) +{ + debug_write_unlock(lock); + __raw_write_unlock(&lock->raw_lock); +} |