include/linux/lockdep.h

Source file repositories/reference/linux-study-clean/include/linux/lockdep.h

File Facts

System
Linux kernel
Corpus path
include/linux/lockdep.h
Extension
.h
Size
21518 bytes
Lines
665
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct lock_list {
	struct list_head		entry;
	struct lock_class		*class;
	struct lock_class		*links_to;
	const struct lock_trace		*trace;
	u16				distance;
	/* bitmap of different dependencies from head to this */
	u8				dep;
	/* used by BFS to record whether "prev -> this" only has -(*R)-> */
	u8				only_xr;

	/*
	 * The parent field is used to implement breadth-first search, and the
	 * bit 0 is reused to indicate if the lock has been accessed in BFS.
	 */
	struct lock_list		*parent;
};

/**
 * struct lock_chain - lock dependency chain record
 *
 * @irq_context: the same as irq_context in held_lock below
 * @depth:       the number of held locks in this chain
 * @base:        the index in chain_hlocks for this chain
 * @entry:       the collided lock chains in lock_chain hash list
 * @chain_key:   the hash key of this lock_chain
 */
struct lock_chain {
	/* see BUILD_BUG_ON()s in add_chain_cache() */
	unsigned int			irq_context :  2,
					depth       :  6,
					base	    : 24;
	/* 4 byte hole */
	struct hlist_node		entry;
	u64				chain_key;
};

/*
 * Initialization, self-test and debugging-output methods:
 */
extern void lockdep_init(void);
extern void lockdep_reset(void);
extern void lockdep_reset_lock(struct lockdep_map *lock);
extern void lockdep_free_key_range(void *start, unsigned long size);
extern asmlinkage void lockdep_sys_exit(void);
extern void lockdep_set_selftest_task(struct task_struct *task);

extern void lockdep_init_task(struct task_struct *task);

/*
 * Split the recursion counter in two to readily detect 'off' vs recursion.
 */
#define LOCKDEP_RECURSION_BITS	16
#define LOCKDEP_OFF		(1U << LOCKDEP_RECURSION_BITS)
#define LOCKDEP_RECURSION_MASK	(LOCKDEP_OFF - 1)

/*
 * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
 * to header dependencies.
 */

#define lockdep_off()					\
do {							\
	current->lockdep_recursion += LOCKDEP_OFF;	\
} while (0)

#define lockdep_on()					\
do {							\
	current->lockdep_recursion -= LOCKDEP_OFF;	\
} while (0)

extern void lockdep_register_key(struct lock_class_key *key);
extern void lockdep_unregister_key(struct lock_class_key *key);

/*
 * These methods are used by specific locking variants (spinlocks,
 * rwlocks, mutexes and rwsems) to pass init/acquire/release events
 * to lockdep:
 */

extern void lockdep_init_map_type(struct lockdep_map *lock, const char *name,
	struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);

static inline void
lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
		       struct lock_class_key *key, int subclass, u8 inner, u8 outer)
{
	lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);
}

Annotation

Implementation Notes