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 enum {
51 #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE |
52 LOCKF_ENABLED_IRQ =
53 #include "lockdep_states.h"
54 0,
55 #undef LOCKDEP_STATE
56
57 #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE |
58 LOCKF_USED_IN_IRQ =
59 #include "lockdep_states.h"
60 0,
61 #undef LOCKDEP_STATE
62
63 #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE##_READ |
64 LOCKF_ENABLED_IRQ_READ =
65 #include "lockdep_states.h"
66 0,
67 #undef LOCKDEP_STATE
68
69 #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE##_READ |
70 LOCKF_USED_IN_IRQ_READ =
71 #include "lockdep_states.h"
72 0,
73 #undef LOCKDEP_STATE
74 };
75
76 #define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ)
77 #define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ)
78
79 #define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ)
80 #define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_READ)
81
82 /*
83 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
84 * .data and .bss to fit in required 32MB limit for the kernel. With
85 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
86 * So, reduce the static allocations for lockdeps related structures so that
87 * everything fits in current required size limit.
88 */
89 #ifdef CONFIG_LOCKDEP_SMALL
90 /*
91 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
92 * we track.
93 *
94 * We use the per-lock dependency maps in two ways: we grow it by adding
95 * every to-be-taken lock to all currently held lock's own dependency
96 * table (if it's not there yet), and we check it for lock order
97 * conflicts and deadlocks.
98 */
99 #define MAX_LOCKDEP_ENTRIES 16384UL
100 #define MAX_LOCKDEP_CHAINS_BITS 15
101 #define MAX_STACK_TRACE_ENTRIES 262144UL
102 #define STACK_TRACE_HASH_SIZE 8192
103 #else
104 #define MAX_LOCKDEP_ENTRIES (1UL << CONFIG_LOCKDEP_BITS)
105
106 #define MAX_LOCKDEP_CHAINS_BITS CONFIG_LOCKDEP_CHAINS_BITS
107
108 /*
109 * Stack-trace: tightly packed array of stack backtrace
110 * addresses. Protected by the hash_lock.
111 */
112 #define MAX_STACK_TRACE_ENTRIES (1UL << CONFIG_LOCKDEP_STACK_TRACE_BITS)
113 #define STACK_TRACE_HASH_SIZE (1 << CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS)
114 #endif
115
116 /*
117 * Bit definitions for lock_chain.irq_context
118 */
119 #define LOCK_CHAIN_SOFTIRQ_CONTEXT (1 << 0)
120 #define LOCK_CHAIN_HARDIRQ_CONTEXT (1 << 1)
121
122 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
123
124 #define AVG_LOCKDEP_CHAIN_DEPTH 5
125 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS * AVG_LOCKDEP_CHAIN_DEPTH)
126
127 extern struct lock_chain lock_chains[];
128
129 #define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)
130
131 extern void get_usage_chars(struct lock_class *class,
132 char usage[LOCK_USAGE_CHARS]);
133
134 extern const char *__get_key_name(const struct lockdep_subclass_key *key,
135 char *str);
136
137 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
138
139 extern unsigned long nr_lock_classes;
140 extern unsigned long nr_zapped_classes;
141 extern unsigned long nr_zapped_lock_chains;
142 extern unsigned long nr_list_entries;
143 extern unsigned long nr_dynamic_keys;
144 long lockdep_next_lockchain(long i);
145 unsigned long lock_chain_count(void);
146 extern unsigned long nr_stack_trace_entries;
147
148 extern unsigned int nr_hardirq_chains;
149 extern unsigned int nr_softirq_chains;
150 extern unsigned int nr_process_chains;
151 extern unsigned int nr_free_chain_hlocks;
152 extern unsigned int nr_lost_chain_hlocks;
153 extern unsigned int nr_large_chain_blocks;
154
155 extern unsigned int max_lockdep_depth;
156 extern unsigned int max_bfs_queue_depth;
157 extern unsigned long max_lock_class_idx;
158
159 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
160 extern unsigned long lock_classes_in_use[];
161
162 #ifdef CONFIG_PROVE_LOCKING
163 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
164 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
165 #ifdef CONFIG_TRACE_IRQFLAGS
166 u64 lockdep_stack_trace_count(void);
167 u64 lockdep_stack_hash_count(void);
168 #endif
169 #else
170 static inline unsigned long
lockdep_count_forward_deps(struct lock_class * class)171 lockdep_count_forward_deps(struct lock_class *class)
172 {
173 return 0;
174 }
175 static inline unsigned long
lockdep_count_backward_deps(struct lock_class * class)176 lockdep_count_backward_deps(struct lock_class *class)
177 {
178 return 0;
179 }
180 #endif
181
182 #ifdef CONFIG_DEBUG_LOCKDEP
183
184 #include <asm/local.h>
185 /*
186 * Various lockdep statistics.
187 * We want them per cpu as they are often accessed in fast path
188 * and we want to avoid too much cache bouncing.
189 */
190 struct lockdep_stats {
191 unsigned long chain_lookup_hits;
192 unsigned int chain_lookup_misses;
193 unsigned long hardirqs_on_events;
194 unsigned long hardirqs_off_events;
195 unsigned long redundant_hardirqs_on;
196 unsigned long redundant_hardirqs_off;
197 unsigned long softirqs_on_events;
198 unsigned long softirqs_off_events;
199 unsigned long redundant_softirqs_on;
200 unsigned long redundant_softirqs_off;
201 int nr_unused_locks;
202 unsigned int nr_redundant_checks;
203 unsigned int nr_redundant;
204 unsigned int nr_cyclic_checks;
205 unsigned int nr_find_usage_forwards_checks;
206 unsigned int nr_find_usage_backwards_checks;
207
208 /*
209 * Per lock class locking operation stat counts
210 */
211 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
212 };
213
214 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
215
216 #define __debug_atomic_inc(ptr) \
217 this_cpu_inc(lockdep_stats.ptr);
218
219 #define debug_atomic_inc(ptr) { \
220 WARN_ON_ONCE(!irqs_disabled()); \
221 __this_cpu_inc(lockdep_stats.ptr); \
222 }
223
224 #define debug_atomic_dec(ptr) { \
225 WARN_ON_ONCE(!irqs_disabled()); \
226 __this_cpu_dec(lockdep_stats.ptr); \
227 }
228
229 #define debug_atomic_read(ptr) ({ \
230 struct lockdep_stats *__cpu_lockdep_stats; \
231 unsigned long long __total = 0; \
232 int __cpu; \
233 for_each_possible_cpu(__cpu) { \
234 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \
235 __total += __cpu_lockdep_stats->ptr; \
236 } \
237 __total; \
238 })
239
debug_class_ops_inc(struct lock_class * class)240 static inline void debug_class_ops_inc(struct lock_class *class)
241 {
242 int idx;
243
244 idx = class - lock_classes;
245 __debug_atomic_inc(lock_class_ops[idx]);
246 }
247
debug_class_ops_read(struct lock_class * class)248 static inline unsigned long debug_class_ops_read(struct lock_class *class)
249 {
250 int idx, cpu;
251 unsigned long ops = 0;
252
253 idx = class - lock_classes;
254 for_each_possible_cpu(cpu)
255 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
256 return ops;
257 }
258
259 #else
260 # define __debug_atomic_inc(ptr) do { } while (0)
261 # define debug_atomic_inc(ptr) do { } while (0)
262 # define debug_atomic_dec(ptr) do { } while (0)
263 # define debug_atomic_read(ptr) 0
264 # define debug_class_ops_inc(ptr) do { } while (0)
265 #endif
266