aboutsummaryrefslogtreecommitdiff
path: root/kernel/locking/lockdep_internals.h
blob: de49f9e1c11ba8be13fffcda9159c9c91db16e85 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/* 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	32768UL

#define MAX_LOCKDEP_CHAINS_BITS	16

/*
 * Stack-trace: tightly packed array of stack backtrace
 * addresses. Protected by the hash_lock.
 */
#define MAX_STACK_TRACE_ENTRIES	524288UL
#define STACK_TRACE_HASH_SIZE	16384
#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