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_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
34 enum {
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 |
46 static 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 |
52 static 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 |
58 static 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 |
64 static 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 /*
110 * Bit definitions for lock_chain.irq_context
111 */
112 #define LOCK_CHAIN_SOFTIRQ_CONTEXT (1 << 0)
113 #define LOCK_CHAIN_HARDIRQ_CONTEXT (1 << 1)
114
115 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
116
117 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
118
119 extern struct list_head all_lock_classes;
120 extern struct lock_chain lock_chains[];
121
122 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
123
124 extern void get_usage_chars(struct lock_class *class,
125 char usage[LOCK_USAGE_CHARS]);
126
127 extern const char *__get_key_name(const struct lockdep_subclass_key *key,
128 char *str);
129
130 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
131
132 extern unsigned long nr_lock_classes;
133 extern unsigned long nr_list_entries;
134 long lockdep_next_lockchain(long i);
135 unsigned long lock_chain_count(void);
136 extern int nr_chain_hlocks;
137 extern unsigned long nr_stack_trace_entries;
138
139 extern unsigned int nr_hardirq_chains;
140 extern unsigned int nr_softirq_chains;
141 extern unsigned int nr_process_chains;
142 extern unsigned int max_lockdep_depth;
143
144 extern unsigned int max_bfs_queue_depth;
145
146 #ifdef CONFIG_PROVE_LOCKING
147 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
148 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
149 #ifdef CONFIG_TRACE_IRQFLAGS
150 u64 lockdep_stack_trace_count(void);
151 u64 lockdep_stack_hash_count(void);
152 #endif
153 #else
154 static inline unsigned long
lockdep_count_forward_deps(struct lock_class * class)155 lockdep_count_forward_deps(struct lock_class *class)
156 {
157 return 0;
158 }
159 static inline unsigned long
lockdep_count_backward_deps(struct lock_class * class)160 lockdep_count_backward_deps(struct lock_class *class)
161 {
162 return 0;
163 }
164 #endif
165
166 #ifdef CONFIG_DEBUG_LOCKDEP
167
168 #include <asm/local.h>
169 /*
170 * Various lockdep statistics.
171 * We want them per cpu as they are often accessed in fast path
172 * and we want to avoid too much cache bouncing.
173 */
174 struct lockdep_stats {
175 unsigned long chain_lookup_hits;
176 unsigned int chain_lookup_misses;
177 unsigned long hardirqs_on_events;
178 unsigned long hardirqs_off_events;
179 unsigned long redundant_hardirqs_on;
180 unsigned long redundant_hardirqs_off;
181 unsigned long softirqs_on_events;
182 unsigned long softirqs_off_events;
183 unsigned long redundant_softirqs_on;
184 unsigned long redundant_softirqs_off;
185 int nr_unused_locks;
186 unsigned int nr_redundant_checks;
187 unsigned int nr_redundant;
188 unsigned int nr_cyclic_checks;
189 unsigned int nr_find_usage_forwards_checks;
190 unsigned int nr_find_usage_backwards_checks;
191
192 /*
193 * Per lock class locking operation stat counts
194 */
195 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
196 };
197
198 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
199 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
200
201 #define __debug_atomic_inc(ptr) \
202 this_cpu_inc(lockdep_stats.ptr);
203
204 #define debug_atomic_inc(ptr) { \
205 WARN_ON_ONCE(!irqs_disabled()); \
206 __this_cpu_inc(lockdep_stats.ptr); \
207 }
208
209 #define debug_atomic_dec(ptr) { \
210 WARN_ON_ONCE(!irqs_disabled()); \
211 __this_cpu_dec(lockdep_stats.ptr); \
212 }
213
214 #define debug_atomic_read(ptr) ({ \
215 struct lockdep_stats *__cpu_lockdep_stats; \
216 unsigned long long __total = 0; \
217 int __cpu; \
218 for_each_possible_cpu(__cpu) { \
219 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \
220 __total += __cpu_lockdep_stats->ptr; \
221 } \
222 __total; \
223 })
224
debug_class_ops_inc(struct lock_class * class)225 static inline void debug_class_ops_inc(struct lock_class *class)
226 {
227 int idx;
228
229 idx = class - lock_classes;
230 __debug_atomic_inc(lock_class_ops[idx]);
231 }
232
debug_class_ops_read(struct lock_class * class)233 static inline unsigned long debug_class_ops_read(struct lock_class *class)
234 {
235 int idx, cpu;
236 unsigned long ops = 0;
237
238 idx = class - lock_classes;
239 for_each_possible_cpu(cpu)
240 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
241 return ops;
242 }
243
244 #else
245 # define __debug_atomic_inc(ptr) do { } while (0)
246 # define debug_atomic_inc(ptr) do { } while (0)
247 # define debug_atomic_dec(ptr) do { } while (0)
248 # define debug_atomic_read(ptr) 0
249 # define debug_class_ops_inc(ptr) do { } while (0)
250 #endif
251