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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237/* * 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/spinlock.h>#include <linux/nmi.h>#include <linux/interrupt.h>#include <linux/debug_locks.h>#include <linux/delay.h>#include <linux/export.h>#include <linux/pid.h>
void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, struct lock_class_key *key, short inner){#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_wait(&lock->dep_map, name, key, 0, inner);#endif lock->raw_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; lock->magic = SPINLOCK_MAGIC; lock->owner = SPINLOCK_OWNER_INIT; lock->owner_cpu = -1;}
EXPORT_SYMBOL(__raw_spin_lock_init);
#ifndef CONFIG_PREEMPT_RTvoid __rwlock_init(rwlock_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_wait(&lock->dep_map, name, key, 0, LD_WAIT_CONFIG);#endif lock->raw_lock = (arch_rwlock_t) __ARCH_RW_LOCK_UNLOCKED; lock->magic = RWLOCK_MAGIC; lock->owner = SPINLOCK_OWNER_INIT; lock->owner_cpu = -1;}
EXPORT_SYMBOL(__rwlock_init);#endif
static void spin_dump(raw_spinlock_t *lock, const char *msg){ struct task_struct *owner = READ_ONCE(lock->owner);
if (owner == SPINLOCK_OWNER_INIT) owner = NULL; printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", msg, raw_smp_processor_id(), current->comm, task_pid_nr(current)); printk(KERN_EMERG " lock: %pS, .magic: %08x, .owner: %s/%d, " ".owner_cpu: %d\n", lock, READ_ONCE(lock->magic), owner ? owner->comm : "<none>", owner ? task_pid_nr(owner) : -1, READ_ONCE(lock->owner_cpu)); dump_stack();}
static void spin_bug(raw_spinlock_t *lock, const char *msg){ if (!debug_locks_off()) return;
spin_dump(lock, msg);}
#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)
static inline voiddebug_spin_lock_before(raw_spinlock_t *lock){ SPIN_BUG_ON(READ_ONCE(lock->magic) != SPINLOCK_MAGIC, lock, "bad magic"); SPIN_BUG_ON(READ_ONCE(lock->owner) == current, lock, "recursion"); SPIN_BUG_ON(READ_ONCE(lock->owner_cpu) == raw_smp_processor_id(), lock, "cpu recursion");}
static inline void debug_spin_lock_after(raw_spinlock_t *lock){ WRITE_ONCE(lock->owner_cpu, raw_smp_processor_id()); WRITE_ONCE(lock->owner, current);}
static inline void debug_spin_unlock(raw_spinlock_t *lock){ SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); SPIN_BUG_ON(!raw_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"); WRITE_ONCE(lock->owner, SPINLOCK_OWNER_INIT); WRITE_ONCE(lock->owner_cpu, -1);}
/* * We are now relying on the NMI watchdog to detect lockup instead of doing * the detection here with an unfair lock which can cause problem of its own. */void do_raw_spin_lock(raw_spinlock_t *lock){ debug_spin_lock_before(lock); arch_spin_lock(&lock->raw_lock); mmiowb_spin_lock(); debug_spin_lock_after(lock);}
int do_raw_spin_trylock(raw_spinlock_t *lock){ int ret = arch_spin_trylock(&lock->raw_lock);
if (ret) { mmiowb_spin_lock(); 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 do_raw_spin_unlock(raw_spinlock_t *lock){ mmiowb_spin_unlock(); debug_spin_unlock(lock); arch_spin_unlock(&lock->raw_lock);}
#ifndef CONFIG_PREEMPT_RTstatic void rwlock_bug(rwlock_t *lock, const char *msg){ if (!debug_locks_off()) return;
printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", msg, raw_smp_processor_id(), current->comm, task_pid_nr(current), lock); dump_stack();}
#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)
void do_raw_read_lock(rwlock_t *lock){ RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); arch_read_lock(&lock->raw_lock);}
int do_raw_read_trylock(rwlock_t *lock){ int ret = arch_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 do_raw_read_unlock(rwlock_t *lock){ RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); arch_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(READ_ONCE(lock->owner) == current, lock, "recursion"); RWLOCK_BUG_ON(READ_ONCE(lock->owner_cpu) == raw_smp_processor_id(), lock, "cpu recursion");}
static inline void debug_write_lock_after(rwlock_t *lock){ WRITE_ONCE(lock->owner_cpu, raw_smp_processor_id()); WRITE_ONCE(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"); WRITE_ONCE(lock->owner, SPINLOCK_OWNER_INIT); WRITE_ONCE(lock->owner_cpu, -1);}
void do_raw_write_lock(rwlock_t *lock){ debug_write_lock_before(lock); arch_write_lock(&lock->raw_lock); debug_write_lock_after(lock);}
int do_raw_write_trylock(rwlock_t *lock){ int ret = arch_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 do_raw_write_unlock(rwlock_t *lock){ debug_write_unlock(lock); arch_write_unlock(&lock->raw_lock);}
#endif /* !CONFIG_PREEMPT_RT */