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