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 lock_chain lock_chains[];
125
126 #define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)
127
128 extern void get_usage_chars(struct lock_class *class,
129 char usage[LOCK_USAGE_CHARS]);
130
131 extern const char *__get_key_name(const struct lockdep_subclass_key *key,
132 char *str);
133
134 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
135
136 extern unsigned long nr_lock_classes;
137 extern unsigned long nr_zapped_classes;
138 extern unsigned long nr_zapped_lock_chains;
139 extern unsigned long nr_list_entries;
140 long lockdep_next_lockchain(long i);
141 unsigned long lock_chain_count(void);
142 extern unsigned long nr_stack_trace_entries;
143
144 extern unsigned int nr_hardirq_chains;
145 extern unsigned int nr_softirq_chains;
146 extern unsigned int nr_process_chains;
147 extern unsigned int nr_free_chain_hlocks;
148 extern unsigned int nr_lost_chain_hlocks;
149 extern unsigned int nr_large_chain_blocks;
150
151 extern unsigned int max_lockdep_depth;
152 extern unsigned int max_bfs_queue_depth;
153 extern unsigned long max_lock_class_idx;
154
155 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
156 extern unsigned long lock_classes_in_use[];
157
158 #ifdef CONFIG_PROVE_LOCKING
159 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
160 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
161 #ifdef CONFIG_TRACE_IRQFLAGS
162 u64 lockdep_stack_trace_count(void);
163 u64 lockdep_stack_hash_count(void);
164 #endif
165 #else
166 static inline unsigned long
167 lockdep_count_forward_deps(struct lock_class *class)
168 {
169 return 0;
170 }
171 static inline unsigned long
172 lockdep_count_backward_deps(struct lock_class *class)
173 {
174 return 0;
175 }
176 #endif
177
178 #ifdef CONFIG_DEBUG_LOCKDEP
179
180 #include <asm/local.h>
181 /*
182 * Various lockdep statistics.
183 * We want them per cpu as they are often accessed in fast path
184 * and we want to avoid too much cache bouncing.
185 */
186 struct lockdep_stats {
187 unsigned long chain_lookup_hits;
188 unsigned int chain_lookup_misses;
189 unsigned long hardirqs_on_events;
190 unsigned long hardirqs_off_events;
191 unsigned long redundant_hardirqs_on;
192 unsigned long redundant_hardirqs_off;
193 unsigned long softirqs_on_events;
194 unsigned long softirqs_off_events;
195 unsigned long redundant_softirqs_on;
196 unsigned long redundant_softirqs_off;
197 int nr_unused_locks;
198 unsigned int nr_redundant_checks;
199 unsigned int nr_redundant;
200 unsigned int nr_cyclic_checks;
201 unsigned int nr_find_usage_forwards_checks;
202 unsigned int nr_find_usage_backwards_checks;
203
204 /*
205 * Per lock class locking operation stat counts
206 */
207 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
208 };
209
210 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
211
212 #define __debug_atomic_inc(ptr) \
213 this_cpu_inc(lockdep_stats.ptr);
214
215 #define debug_atomic_inc(ptr) { \
216 WARN_ON_ONCE(!irqs_disabled()); \
217 __this_cpu_inc(lockdep_stats.ptr); \
218 }
219
220 #define debug_atomic_dec(ptr) { \
221 WARN_ON_ONCE(!irqs_disabled()); \
222 __this_cpu_dec(lockdep_stats.ptr); \
223 }
224
225 #define debug_atomic_read(ptr) ({ \
226 struct lockdep_stats *__cpu_lockdep_stats; \
227 unsigned long long __total = 0; \
228 int __cpu; \
229 for_each_possible_cpu(__cpu) { \
230 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \
231 __total += __cpu_lockdep_stats->ptr; \
232 } \
233 __total; \
234 })
235
236 static inline void debug_class_ops_inc(struct lock_class *class)
237 {
238 int idx;
239
240 idx = class - lock_classes;
241 __debug_atomic_inc(lock_class_ops[idx]);
242 }
243
244 static inline unsigned long debug_class_ops_read(struct lock_class *class)
245 {
246 int idx, cpu;
247 unsigned long ops = 0;
248
249 idx = class - lock_classes;
250 for_each_possible_cpu(cpu)
251 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
252 return ops;
253 }
254
255 #else
256 # define __debug_atomic_inc(ptr) do { } while (0)
257 # define debug_atomic_inc(ptr) do { } while (0)
258 # define debug_atomic_dec(ptr) do { } while (0)
259 # define debug_atomic_read(ptr) 0
260 # define debug_class_ops_inc(ptr) do { } while (0)
261 #endif
262
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