kernel/locking/lockdep_internals.h - linux - Git at Google

 /* 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 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;
 extern unsigned long max_lock_class_idx;

 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 extern unsigned long lock_classes_in_use[];

 #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);

 #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
	/* 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 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;
	extern unsigned long max_lock_class_idx;

	extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
	extern unsigned long lock_classes_in_use[];

	#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);

	#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