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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 */
13enum 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 */
27static_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
38enum {
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
50enum {
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
127extern struct lock_chain lock_chains[];
128
129#define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)
130
131extern void get_usage_chars(struct lock_class *class,
132 char usage[LOCK_USAGE_CHARS]);
133
134extern const char *__get_key_name(const struct lockdep_subclass_key *key,
135 char *str);
136
137struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
138
139extern unsigned long nr_lock_classes;
140extern unsigned long nr_zapped_classes;
141extern unsigned long nr_zapped_lock_chains;
142extern unsigned long nr_list_entries;
143extern unsigned long nr_dynamic_keys;
144long lockdep_next_lockchain(long i);
145unsigned long lock_chain_count(void);
146extern unsigned long nr_stack_trace_entries;
147
148extern unsigned int nr_hardirq_chains;
149extern unsigned int nr_softirq_chains;
150extern unsigned int nr_process_chains;
151extern unsigned int nr_free_chain_hlocks;
152extern unsigned int nr_lost_chain_hlocks;
153extern unsigned int nr_large_chain_blocks;
154
155extern unsigned int max_lockdep_depth;
156extern unsigned int max_bfs_queue_depth;
157extern unsigned long max_lock_class_idx;
158
159extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
160extern unsigned long lock_classes_in_use[];
161
162#ifdef CONFIG_PROVE_LOCKING
163extern unsigned long lockdep_count_forward_deps(struct lock_class *);
164extern unsigned long lockdep_count_backward_deps(struct lock_class *);
165#ifdef CONFIG_TRACE_IRQFLAGS
166u64 lockdep_stack_trace_count(void);
167u64 lockdep_stack_hash_count(void);
168#endif
169#else
170static inline unsigned long
171lockdep_count_forward_deps(struct lock_class *class)
172{
173 return 0;
174}
175static inline unsigned long
176lockdep_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 */
190struct 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
214DECLARE_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
240static 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
248static 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