[linux-2.6-block.git] / kernel / locking / lockdep_internals.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * kernel/lockdep_internals.h
 *
 * Runtime locking correctness validator
 *
 * lockdep subsystem internal functions and variables.
 */

/*
 * Lock-class usage-state bits:
 */
enum lock_usage_bit {
#define LOCKDEP_STATE(__STATE)		\
	LOCK_USED_IN_##__STATE,		\
	LOCK_USED_IN_##__STATE##_READ,	\
	LOCK_ENABLED_##__STATE,		\
	LOCK_ENABLED_##__STATE##_READ,
#include "lockdep_states.h"
#undef LOCKDEP_STATE
	LOCK_USED,
	LOCK_USED_READ,
	LOCK_USAGE_STATES,
};

/* states after LOCK_USED_READ are not traced and printed */
static_assert(LOCK_TRACE_STATES == LOCK_USAGE_STATES);

#define LOCK_USAGE_READ_MASK 1
#define LOCK_USAGE_DIR_MASK  2
#define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK))

/*
 * Usage-state bitmasks:
 */
#define __LOCKF(__STATE)	LOCKF_##__STATE = (1 << LOCK_##__STATE),

enum {
#define LOCKDEP_STATE(__STATE)						\
	__LOCKF(USED_IN_##__STATE)					\
	__LOCKF(USED_IN_##__STATE##_READ)				\
	__LOCKF(ENABLED_##__STATE)					\
	__LOCKF(ENABLED_##__STATE##_READ)
#include "lockdep_states.h"
#undef LOCKDEP_STATE
	__LOCKF(USED)
	__LOCKF(USED_READ)
};

#define LOCKDEP_STATE(__STATE)	LOCKF_ENABLED_##__STATE |
static const unsigned long LOCKF_ENABLED_IRQ =
#include "lockdep_states.h"
	0;
#undef LOCKDEP_STATE

#define LOCKDEP_STATE(__STATE)	LOCKF_USED_IN_##__STATE |
static const unsigned long LOCKF_USED_IN_IRQ =
#include "lockdep_states.h"
	0;
#undef LOCKDEP_STATE

#define LOCKDEP_STATE(__STATE)	LOCKF_ENABLED_##__STATE##_READ |
static const unsigned long LOCKF_ENABLED_IRQ_READ =
#include "lockdep_states.h"
	0;
#undef LOCKDEP_STATE

#define LOCKDEP_STATE(__STATE)	LOCKF_USED_IN_##__STATE##_READ |
static const unsigned long LOCKF_USED_IN_IRQ_READ =
#include "lockdep_states.h"
	0;
#undef LOCKDEP_STATE

#define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ)
#define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ)

#define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ)
#define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_READ)

/*
 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
 * .data and .bss to fit in required 32MB limit for the kernel. With
 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
 * So, reduce the static allocations for lockdeps related structures so that
 * everything fits in current required size limit.
 */
#ifdef CONFIG_LOCKDEP_SMALL
/*
 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
 * we track.
 *
 * We use the per-lock dependency maps in two ways: we grow it by adding
 * every to-be-taken lock to all currently held lock's own dependency
 * table (if it's not there yet), and we check it for lock order
 * conflicts and deadlocks.
 */
#define MAX_LOCKDEP_ENTRIES	16384UL
#define MAX_LOCKDEP_CHAINS_BITS	15
#define MAX_STACK_TRACE_ENTRIES	262144UL
#define STACK_TRACE_HASH_SIZE	8192
#else
#define MAX_LOCKDEP_ENTRIES	(1UL << CONFIG_LOCKDEP_BITS)

#define MAX_LOCKDEP_CHAINS_BITS	CONFIG_LOCKDEP_CHAINS_BITS

/*
 * Stack-trace: tightly packed array of stack backtrace
 * addresses. Protected by the hash_lock.
 */
#define MAX_STACK_TRACE_ENTRIES	(1UL << CONFIG_LOCKDEP_STACK_TRACE_BITS)
#define STACK_TRACE_HASH_SIZE	(1 << CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS)
#endif

/*
 * Bit definitions for lock_chain.irq_context
 */
#define LOCK_CHAIN_SOFTIRQ_CONTEXT	(1 << 0)
#define LOCK_CHAIN_HARDIRQ_CONTEXT	(1 << 1)

#define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)

#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)

extern struct list_head all_lock_classes;
extern struct lock_chain lock_chains[];

#define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)

extern void get_usage_chars(struct lock_class *class,
			    char usage[LOCK_USAGE_CHARS]);

extern const char *__get_key_name(const struct lockdep_subclass_key *key,
				  char *str);

struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);

extern unsigned long nr_lock_classes;
extern unsigned long nr_zapped_classes;
extern unsigned long nr_zapped_lock_chains;
extern unsigned long nr_list_entries;
long lockdep_next_lockchain(long i);
unsigned long lock_chain_count(void);
extern unsigned long nr_stack_trace_entries;

extern unsigned int nr_hardirq_chains;
extern unsigned int nr_softirq_chains;
extern unsigned int nr_process_chains;
extern unsigned int nr_free_chain_hlocks;
extern unsigned int nr_lost_chain_hlocks;
extern unsigned int nr_large_chain_blocks;

extern unsigned int max_lockdep_depth;
extern unsigned int max_bfs_queue_depth;

#ifdef CONFIG_PROVE_LOCKING
extern unsigned long lockdep_count_forward_deps(struct lock_class *);
extern unsigned long lockdep_count_backward_deps(struct lock_class *);
#ifdef CONFIG_TRACE_IRQFLAGS
u64 lockdep_stack_trace_count(void);
u64 lockdep_stack_hash_count(void);
#endif
#else
static inline unsigned long
lockdep_count_forward_deps(struct lock_class *class)
{
	return 0;
}
static inline unsigned long
lockdep_count_backward_deps(struct lock_class *class)
{
	return 0;
}
#endif

#ifdef CONFIG_DEBUG_LOCKDEP

#include <asm/local.h>
/*
 * Various lockdep statistics.
 * We want them per cpu as they are often accessed in fast path
 * and we want to avoid too much cache bouncing.
 */
struct lockdep_stats {
	unsigned long  chain_lookup_hits;
	unsigned int   chain_lookup_misses;
	unsigned long  hardirqs_on_events;
	unsigned long  hardirqs_off_events;
	unsigned long  redundant_hardirqs_on;
	unsigned long  redundant_hardirqs_off;
	unsigned long  softirqs_on_events;
	unsigned long  softirqs_off_events;
	unsigned long  redundant_softirqs_on;
	unsigned long  redundant_softirqs_off;
	int            nr_unused_locks;
	unsigned int   nr_redundant_checks;
	unsigned int   nr_redundant;
	unsigned int   nr_cyclic_checks;
	unsigned int   nr_find_usage_forwards_checks;
	unsigned int   nr_find_usage_backwards_checks;

	/*
	 * Per lock class locking operation stat counts
	 */
	unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
};

DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];

#define __debug_atomic_inc(ptr)					\
	this_cpu_inc(lockdep_stats.ptr);

#define debug_atomic_inc(ptr)			{		\
	WARN_ON_ONCE(!irqs_disabled());				\
	__this_cpu_inc(lockdep_stats.ptr);			\
}

#define debug_atomic_dec(ptr)			{		\
	WARN_ON_ONCE(!irqs_disabled());				\
	__this_cpu_dec(lockdep_stats.ptr);			\
}

#define debug_atomic_read(ptr)		({				\
	struct lockdep_stats *__cpu_lockdep_stats;			\
	unsigned long long __total = 0;					\
	int __cpu;							\
	for_each_possible_cpu(__cpu) {					\
		__cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);	\
		__total += __cpu_lockdep_stats->ptr;			\
	}								\
	__total;							\
})

static inline void debug_class_ops_inc(struct lock_class *class)
{
	int idx;

	idx = class - lock_classes;
	__debug_atomic_inc(lock_class_ops[idx]);
}

static inline unsigned long debug_class_ops_read(struct lock_class *class)
{
	int idx, cpu;
	unsigned long ops = 0;

	idx = class - lock_classes;
	for_each_possible_cpu(cpu)
		ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
	return ops;
}

#else
# define __debug_atomic_inc(ptr)	do { } while (0)
# define debug_atomic_inc(ptr)		do { } while (0)
# define debug_atomic_dec(ptr)		do { } while (0)
# define debug_atomic_read(ptr)		0
# define debug_class_ops_inc(ptr)	do { } while (0)
#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
fbb9ce95 IM	2	/*
	3	* kernel/lockdep_internals.h
	4	*
	5	* Runtime locking correctness validator
	6	*
	7	* lockdep subsystem internal functions and variables.
	8	*/
	9
9851673b PZ	10	/*
	11	* Lock-class usage-state bits:
	12	*/
	13	enum lock_usage_bit {
d7b1b021 PZ	14	#define LOCKDEP_STATE(__STATE) \
	15	LOCK_USED_IN_##__STATE, \
	16	LOCK_USED_IN_##__STATE##_READ, \
	17	LOCK_ENABLED_##__STATE, \
	18	LOCK_ENABLED_##__STATE##_READ,
	19	#include "lockdep_states.h"
	20	#undef LOCKDEP_STATE
	21	LOCK_USED,
23870f12	22	LOCK_USED_READ,
2bb8945b	23	LOCK_USAGE_STATES,
9851673b PZ	24	};
9851673b PZ	25
2bb8945b PZ	26	/* states after LOCK_USED_READ are not traced and printed */
	27	static_assert(LOCK_TRACE_STATES == LOCK_USAGE_STATES);
	28
bba2a8f1 FW	29	#define LOCK_USAGE_READ_MASK 1
	30	#define LOCK_USAGE_DIR_MASK 2
	31	#define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK \| LOCK_USAGE_DIR_MASK))
	32
9851673b PZ	33	/*
	34	* Usage-state bitmasks:
	35	*/
d7b1b021 PZ	36	#define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE),
	37
	38	enum {
	39	#define LOCKDEP_STATE(__STATE) \
	40	__LOCKF(USED_IN_##__STATE) \
	41	__LOCKF(USED_IN_##__STATE##_READ) \
	42	__LOCKF(ENABLED_##__STATE) \
	43	__LOCKF(ENABLED_##__STATE##_READ)
	44	#include "lockdep_states.h"
	45	#undef LOCKDEP_STATE
	46	__LOCKF(USED)
23870f12	47	__LOCKF(USED_READ)
d7b1b021	48	};
9851673b	49
8808a7c6 PZ	50	#define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE \|
	51	static const unsigned long LOCKF_ENABLED_IRQ =
	52	#include "lockdep_states.h"
	53	0;
	54	#undef LOCKDEP_STATE
	55
	56	#define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE \|
	57	static const unsigned long LOCKF_USED_IN_IRQ =
	58	#include "lockdep_states.h"
	59	0;
	60	#undef LOCKDEP_STATE
9851673b	61
8808a7c6 PZ	62	#define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE##_READ \|
	63	static const unsigned long LOCKF_ENABLED_IRQ_READ =
	64	#include "lockdep_states.h"
	65	0;
	66	#undef LOCKDEP_STATE
	67
	68	#define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE##_READ \|
	69	static const unsigned long LOCKF_USED_IN_IRQ_READ =
	70	#include "lockdep_states.h"
	71	0;
	72	#undef LOCKDEP_STATE
9851673b	73
948f8376 FW	74	#define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ \| LOCKF_ENABLED_IRQ_READ)
	75	#define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ \| LOCKF_USED_IN_IRQ_READ)
	76
	77	#define LOCKF_IRQ (LOCKF_ENABLED_IRQ \| LOCKF_USED_IN_IRQ)
	78	#define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ \| LOCKF_USED_IN_IRQ_READ)
	79
e245d99e	80	/*
395102db	81	* CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
e245d99e	82	* .data and .bss to fit in required 32MB limit for the kernel. With
395102db	83	* CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
e245d99e BM	84	* So, reduce the static allocations for lockdeps related structures so that
	85	* everything fits in current required size limit.
	86	*/
395102db	87	#ifdef CONFIG_LOCKDEP_SMALL
fbb9ce95 IM	88	/*
	89	* MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
	90	* we track.
	91	*
	92	* We use the per-lock dependency maps in two ways: we grow it by adding
	93	* every to-be-taken lock to all currently held lock's own dependency
	94	* table (if it's not there yet), and we check it for lock order
	95	* conflicts and deadlocks.
	96	*/
e245d99e BM	97	#define MAX_LOCKDEP_ENTRIES 16384UL
	98	#define MAX_LOCKDEP_CHAINS_BITS 15
	99	#define MAX_STACK_TRACE_ENTRIES 262144UL
12593b74	100	#define STACK_TRACE_HASH_SIZE 8192
e245d99e	101	#else
5dc33592	102	#define MAX_LOCKDEP_ENTRIES (1UL << CONFIG_LOCKDEP_BITS)
fbb9ce95	103
5dc33592	104	#define MAX_LOCKDEP_CHAINS_BITS CONFIG_LOCKDEP_CHAINS_BITS
443cd507	105
fbb9ce95 IM	106	/*
	107	* Stack-trace: tightly packed array of stack backtrace
	108	* addresses. Protected by the hash_lock.
	109	*/
5dc33592 TH	110	#define MAX_STACK_TRACE_ENTRIES (1UL << CONFIG_LOCKDEP_STACK_TRACE_BITS)
5dc33592 TH	111	#define STACK_TRACE_HASH_SIZE (1 << CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS)
e245d99e BM	112	#endif
e245d99e BM	113
b3b9c187 WL	114	/*
	115	* Bit definitions for lock_chain.irq_context
	116	*/
	117	#define LOCK_CHAIN_SOFTIRQ_CONTEXT (1 << 0)
	118	#define LOCK_CHAIN_HARDIRQ_CONTEXT (1 << 1)
	119
e245d99e BM	120	#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
	121
	122	#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
fbb9ce95 IM	123
fbb9ce95 IM	124	extern struct list_head all_lock_classes;
443cd507	125	extern struct lock_chain lock_chains[];
fbb9ce95	126
2bb8945b	127	#define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)
f510b233 PZ	128
	129	extern void get_usage_chars(struct lock_class *class,
	130	char usage[LOCK_USAGE_CHARS]);
fbb9ce95	131
364f6afc BVA	132	extern const char __get_key_name(const struct lockdep_subclass_key key,
364f6afc BVA	133	char *str);
fbb9ce95	134
443cd507 HY	135	struct lock_class lock_chain_get_class(struct lock_chain chain, int i);
443cd507 HY	136
fbb9ce95	137	extern unsigned long nr_lock_classes;
1d44bcb4	138	extern unsigned long nr_zapped_classes;
797b82eb	139	extern unsigned long nr_zapped_lock_chains;
fbb9ce95	140	extern unsigned long nr_list_entries;
2212684a BVA	141	long lockdep_next_lockchain(long i);
2212684a BVA	142	unsigned long lock_chain_count(void);
fbb9ce95 IM	143	extern unsigned long nr_stack_trace_entries;
	144
	145	extern unsigned int nr_hardirq_chains;
	146	extern unsigned int nr_softirq_chains;
	147	extern unsigned int nr_process_chains;
810507fe WL	148	extern unsigned int nr_free_chain_hlocks;
	149	extern unsigned int nr_lost_chain_hlocks;
	150	extern unsigned int nr_large_chain_blocks;
fbb9ce95	151
836bd74b	152	extern unsigned int max_lockdep_depth;
af012961 PZ	153	extern unsigned int max_bfs_queue_depth;
af012961 PZ	154
d6672c50	155	#ifdef CONFIG_PROVE_LOCKING
419ca3f1 DM	156	extern unsigned long lockdep_count_forward_deps(struct lock_class *);
419ca3f1 DM	157	extern unsigned long lockdep_count_backward_deps(struct lock_class *);
8c779229 BVA	158	#ifdef CONFIG_TRACE_IRQFLAGS
	159	u64 lockdep_stack_trace_count(void);
	160	u64 lockdep_stack_hash_count(void);
	161	#endif
d6672c50 IM	162	#else
	163	static inline unsigned long
	164	lockdep_count_forward_deps(struct lock_class *class)
	165	{
	166	return 0;
	167	}
	168	static inline unsigned long
	169	lockdep_count_backward_deps(struct lock_class *class)
	170	{
	171	return 0;
	172	}
	173	#endif
419ca3f1	174
fbb9ce95	175	#ifdef CONFIG_DEBUG_LOCKDEP
bd6d29c2 FW	176
bd6d29c2 FW	177	#include <asm/local.h>
fbb9ce95	178	/*
bd6d29c2 FW	179	* Various lockdep statistics.
	180	* We want them per cpu as they are often accessed in fast path
	181	* and we want to avoid too much cache bouncing.
fbb9ce95	182	*/
bd6d29c2	183	struct lockdep_stats {
9156e545 KW	184	unsigned long chain_lookup_hits;
	185	unsigned int chain_lookup_misses;
	186	unsigned long hardirqs_on_events;
	187	unsigned long hardirqs_off_events;
	188	unsigned long redundant_hardirqs_on;
	189	unsigned long redundant_hardirqs_off;
	190	unsigned long softirqs_on_events;
	191	unsigned long softirqs_off_events;
	192	unsigned long redundant_softirqs_on;
	193	unsigned long redundant_softirqs_off;
	194	int nr_unused_locks;
	195	unsigned int nr_redundant_checks;
	196	unsigned int nr_redundant;
	197	unsigned int nr_cyclic_checks;
	198	unsigned int nr_find_usage_forwards_checks;
	199	unsigned int nr_find_usage_backwards_checks;
8ca2b56c WL	200
	201	/*
	202	* Per lock class locking operation stat counts
	203	*/
	204	unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
bd6d29c2 FW	205	};
	206
	207	DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
8ca2b56c	208	extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
bd6d29c2	209
ba697f40 FW	210	#define __debug_atomic_inc(ptr) \
	211	this_cpu_inc(lockdep_stats.ptr);
	212
bd6d29c2	213	#define debug_atomic_inc(ptr) { \
bd6d29c2	214	WARN_ON_ONCE(!irqs_disabled()); \
54d47a2b	215	__this_cpu_inc(lockdep_stats.ptr); \
bd6d29c2 FW	216	}
	217
	218	#define debug_atomic_dec(ptr) { \
bd6d29c2	219	WARN_ON_ONCE(!irqs_disabled()); \
54d47a2b	220	__this_cpu_dec(lockdep_stats.ptr); \
bd6d29c2 FW	221	}
	222
	223	#define debug_atomic_read(ptr) ({ \
	224	struct lockdep_stats *__cpu_lockdep_stats; \
	225	unsigned long long __total = 0; \
	226	int __cpu; \
	227	for_each_possible_cpu(__cpu) { \
	228	__cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \
	229	__total += __cpu_lockdep_stats->ptr; \
	230	} \
	231	__total; \
	232	})
8ca2b56c WL	233
	234	static inline void debug_class_ops_inc(struct lock_class *class)
	235	{
	236	int idx;
	237
	238	idx = class - lock_classes;
	239	__debug_atomic_inc(lock_class_ops[idx]);
	240	}
	241
	242	static inline unsigned long debug_class_ops_read(struct lock_class *class)
	243	{
	244	int idx, cpu;
	245	unsigned long ops = 0;
	246
	247	idx = class - lock_classes;
	248	for_each_possible_cpu(cpu)
	249	ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
	250	return ops;
	251	}
	252
fbb9ce95	253	#else
ba697f40	254	# define __debug_atomic_inc(ptr) do { } while (0)
fbb9ce95 IM	255	# define debug_atomic_inc(ptr) do { } while (0)
	256	# define debug_atomic_dec(ptr) do { } while (0)
	257	# define debug_atomic_read(ptr) 0
8ca2b56c	258	# define debug_class_ops_inc(ptr) do { } while (0)
fbb9ce95	259	#endif