1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * kernel/lockdep_internals.h
  4 *
  5 * Runtime locking correctness validator
  6 *
  7 * lockdep subsystem internal functions and variables.
  8 */
  9
 10/*
 11 * Lock-class usage-state bits:
 12 */
 13enum lock_usage_bit {
 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,
 22	LOCK_USAGE_STATES
 23};
 24
 25#define LOCK_USAGE_READ_MASK 1
 26#define LOCK_USAGE_DIR_MASK  2
 27#define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK))
 28
 29/*
 30 * Usage-state bitmasks:
 31 */
 32#define __LOCKF(__STATE)	LOCKF_##__STATE = (1 << LOCK_##__STATE),
 33
 34enum {
 35#define LOCKDEP_STATE(__STATE)						\
 36	__LOCKF(USED_IN_##__STATE)					\
 37	__LOCKF(USED_IN_##__STATE##_READ)				\
 38	__LOCKF(ENABLED_##__STATE)					\
 39	__LOCKF(ENABLED_##__STATE##_READ)
 40#include "lockdep_states.h"
 41#undef LOCKDEP_STATE
 42	__LOCKF(USED)
 43};
 44
 45#define LOCKDEP_STATE(__STATE)	LOCKF_ENABLED_##__STATE |
 46static const unsigned long LOCKF_ENABLED_IRQ =
 47#include "lockdep_states.h"
 48	0;
 49#undef LOCKDEP_STATE
 50
 51#define LOCKDEP_STATE(__STATE)	LOCKF_USED_IN_##__STATE |
 52static const unsigned long LOCKF_USED_IN_IRQ =
 53#include "lockdep_states.h"
 54	0;
 55#undef LOCKDEP_STATE
 56
 57#define LOCKDEP_STATE(__STATE)	LOCKF_ENABLED_##__STATE##_READ |
 58static const unsigned long LOCKF_ENABLED_IRQ_READ =
 59#include "lockdep_states.h"
 60	0;
 61#undef LOCKDEP_STATE
 62
 63#define LOCKDEP_STATE(__STATE)	LOCKF_USED_IN_##__STATE##_READ |
 64static const unsigned long LOCKF_USED_IN_IRQ_READ =
 65#include "lockdep_states.h"
 66	0;
 67#undef LOCKDEP_STATE
 68
 69#define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ)
 70#define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ)
 71
 72#define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ)
 73#define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_READ)
 74
 75/*
 76 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
 77 * .data and .bss to fit in required 32MB limit for the kernel. With
 78 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
 79 * So, reduce the static allocations for lockdeps related structures so that
 80 * everything fits in current required size limit.
 81 */
 82#ifdef CONFIG_LOCKDEP_SMALL
 83/*
 84 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
 85 * we track.
 86 *
 87 * We use the per-lock dependency maps in two ways: we grow it by adding
 88 * every to-be-taken lock to all currently held lock's own dependency
 89 * table (if it's not there yet), and we check it for lock order
 90 * conflicts and deadlocks.
 91 */
 92#define MAX_LOCKDEP_ENTRIES	16384UL
 93#define MAX_LOCKDEP_CHAINS_BITS	15
 94#define MAX_STACK_TRACE_ENTRIES	262144UL
 95#define STACK_TRACE_HASH_SIZE	8192
 96#else
 97#define MAX_LOCKDEP_ENTRIES	32768UL
 98
 99#define MAX_LOCKDEP_CHAINS_BITS	16
100
101/*
102 * Stack-trace: tightly packed array of stack backtrace
103 * addresses. Protected by the hash_lock.
104 */
105#define MAX_STACK_TRACE_ENTRIES	524288UL
106#define STACK_TRACE_HASH_SIZE	16384
107#endif
108
109#define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)
110
111#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
112
113extern struct list_head all_lock_classes;
114extern struct lock_chain lock_chains[];
115
116#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
117
118extern void get_usage_chars(struct lock_class *class,
119			    char usage[LOCK_USAGE_CHARS]);
120
121extern const char *__get_key_name(const struct lockdep_subclass_key *key,
122				  char *str);
123
124struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
125
126extern unsigned long nr_lock_classes;
127extern unsigned long nr_list_entries;
128long lockdep_next_lockchain(long i);
129unsigned long lock_chain_count(void);
130extern int nr_chain_hlocks;
131extern unsigned long nr_stack_trace_entries;
132
133extern unsigned int nr_hardirq_chains;
134extern unsigned int nr_softirq_chains;
135extern unsigned int nr_process_chains;
136extern unsigned int max_lockdep_depth;
137
138extern unsigned int max_bfs_queue_depth;
139
140#ifdef CONFIG_PROVE_LOCKING
141extern unsigned long lockdep_count_forward_deps(struct lock_class *);
142extern unsigned long lockdep_count_backward_deps(struct lock_class *);
143#ifdef CONFIG_TRACE_IRQFLAGS
144u64 lockdep_stack_trace_count(void);
145u64 lockdep_stack_hash_count(void);
146#endif
147#else
148static inline unsigned long
149lockdep_count_forward_deps(struct lock_class *class)
150{
151	return 0;
152}
153static inline unsigned long
154lockdep_count_backward_deps(struct lock_class *class)
155{
156	return 0;
157}
158#endif
159
160#ifdef CONFIG_DEBUG_LOCKDEP
161
162#include <asm/local.h>
163/*
164 * Various lockdep statistics.
165 * We want them per cpu as they are often accessed in fast path
166 * and we want to avoid too much cache bouncing.
167 */
168struct lockdep_stats {
169	unsigned long  chain_lookup_hits;
170	unsigned int   chain_lookup_misses;
171	unsigned long  hardirqs_on_events;
172	unsigned long  hardirqs_off_events;
173	unsigned long  redundant_hardirqs_on;
174	unsigned long  redundant_hardirqs_off;
175	unsigned long  softirqs_on_events;
176	unsigned long  softirqs_off_events;
177	unsigned long  redundant_softirqs_on;
178	unsigned long  redundant_softirqs_off;
179	int            nr_unused_locks;
180	unsigned int   nr_redundant_checks;
181	unsigned int   nr_redundant;
182	unsigned int   nr_cyclic_checks;
183	unsigned int   nr_find_usage_forwards_checks;
184	unsigned int   nr_find_usage_backwards_checks;
185
186	/*
187	 * Per lock class locking operation stat counts
188	 */
189	unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
190};
191
192DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
193extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
194
195#define __debug_atomic_inc(ptr)					\
196	this_cpu_inc(lockdep_stats.ptr);
197
198#define debug_atomic_inc(ptr)			{		\
199	WARN_ON_ONCE(!irqs_disabled());				\
200	__this_cpu_inc(lockdep_stats.ptr);			\
201}
202
203#define debug_atomic_dec(ptr)			{		\
204	WARN_ON_ONCE(!irqs_disabled());				\
205	__this_cpu_dec(lockdep_stats.ptr);			\
206}
207
208#define debug_atomic_read(ptr)		({				\
209	struct lockdep_stats *__cpu_lockdep_stats;			\
210	unsigned long long __total = 0;					\
211	int __cpu;							\
212	for_each_possible_cpu(__cpu) {					\
213		__cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);	\
214		__total += __cpu_lockdep_stats->ptr;			\
215	}								\
216	__total;							\
217})
218
219static inline void debug_class_ops_inc(struct lock_class *class)
220{
221	int idx;
222
223	idx = class - lock_classes;
224	__debug_atomic_inc(lock_class_ops[idx]);
225}
226
227static inline unsigned long debug_class_ops_read(struct lock_class *class)
228{
229	int idx, cpu;
230	unsigned long ops = 0;
231
232	idx = class - lock_classes;
233	for_each_possible_cpu(cpu)
234		ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
235	return ops;
236}
237
238#else
239# define __debug_atomic_inc(ptr)	do { } while (0)
240# define debug_atomic_inc(ptr)		do { } while (0)
241# define debug_atomic_dec(ptr)		do { } while (0)
242# define debug_atomic_read(ptr)		0
243# define debug_class_ops_inc(ptr)	do { } while (0)
244#endif