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 */
13 enum 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_USED_READ,
23 LOCK_USAGE_STATES,
24 };
25
26 /* states after LOCK_USED_READ are not traced and printed */
27 static_assert(LOCK_TRACE_STATES == LOCK_USAGE_STATES);
28
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
33 /*
34 * Usage-state bitmasks:
35 */
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)
47 __LOCKF(USED_READ)
48 };
49
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
61
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
73
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
80 /*
81 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
82 * .data and .bss to fit in required 32MB limit for the kernel. With
83 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
84 * So, reduce the static allocations for lockdeps related structures so that
85 * everything fits in current required size limit.
86 */
87 #ifdef CONFIG_LOCKDEP_SMALL
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 */
97 #define MAX_LOCKDEP_ENTRIES 16384UL
98 #define MAX_LOCKDEP_CHAINS_BITS 15
99 #define MAX_STACK_TRACE_ENTRIES 262144UL
100 #define STACK_TRACE_HASH_SIZE 8192
101 #else
102 #define MAX_LOCKDEP_ENTRIES (1UL << CONFIG_LOCKDEP_BITS)
103
104 #define MAX_LOCKDEP_CHAINS_BITS CONFIG_LOCKDEP_CHAINS_BITS
105
106 /*
107 * Stack-trace: tightly packed array of stack backtrace
108 * addresses. Protected by the hash_lock.
109 */
110 #define MAX_STACK_TRACE_ENTRIES (1UL << CONFIG_LOCKDEP_STACK_TRACE_BITS)
111 #define STACK_TRACE_HASH_SIZE (1 << CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS)
112 #endif
113
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
120 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
121
122 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
123
124 extern struct list_head all_lock_classes;
125 extern struct lock_chain lock_chains[];
126
127 #define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)
128
129 extern void get_usage_chars(struct lock_class *class,
130 char usage[LOCK_USAGE_CHARS]);
131
132 extern const char *__get_key_name(const struct lockdep_subclass_key *key,
133 char *str);
134
135 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
136
137 extern unsigned long nr_lock_classes;
138 extern unsigned long nr_zapped_classes;
139 extern unsigned long nr_zapped_lock_chains;
140 extern unsigned long nr_list_entries;
141 long lockdep_next_lockchain(long i);
142 unsigned long lock_chain_count(void);
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;
148 extern unsigned int nr_free_chain_hlocks;
149 extern unsigned int nr_lost_chain_hlocks;
150 extern unsigned int nr_large_chain_blocks;
151
152 extern unsigned int max_lockdep_depth;
153 extern unsigned int max_bfs_queue_depth;
154
155 #ifdef CONFIG_PROVE_LOCKING
156 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
157 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
158 #ifdef CONFIG_TRACE_IRQFLAGS
159 u64 lockdep_stack_trace_count(void);
160 u64 lockdep_stack_hash_count(void);
161 #endif
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
174
175 #ifdef CONFIG_DEBUG_LOCKDEP
176
177 #include <asm/local.h>
178 /*
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.
182 */
183 struct lockdep_stats {
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;
200
201 /*
202 * Per lock class locking operation stat counts
203 */
204 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
205 };
206
207 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
208 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
209
210 #define __debug_atomic_inc(ptr) \
211 this_cpu_inc(lockdep_stats.ptr);
212
213 #define debug_atomic_inc(ptr) { \
214 WARN_ON_ONCE(!irqs_disabled()); \
215 __this_cpu_inc(lockdep_stats.ptr); \
216 }
217
218 #define debug_atomic_dec(ptr) { \
219 WARN_ON_ONCE(!irqs_disabled()); \
220 __this_cpu_dec(lockdep_stats.ptr); \
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 })
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
253 #else
254 # define __debug_atomic_inc(ptr) do { } while (0)
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
258 # define debug_class_ops_inc(ptr) do { } while (0)
259 #endif
260
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