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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Runtime locking correctness validator
4 *
5 * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
6 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
7 *
8 * see Documentation/locking/lockdep-design.rst for more details.
9 */
10#ifndef __LINUX_LOCKDEP_TYPES_H
11#define __LINUX_LOCKDEP_TYPES_H
12
13#include <linux/types.h>
14
15#define MAX_LOCKDEP_SUBCLASSES 8UL
16
17enum lockdep_wait_type {
18 LD_WAIT_INV = 0, /* not checked, catch all */
19
20 LD_WAIT_FREE, /* wait free, rcu etc.. */
21 LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */
22
23#ifdef CONFIG_PROVE_RAW_LOCK_NESTING
24 LD_WAIT_CONFIG, /* CONFIG_PREEMPT_LOCK, spinlock_t etc.. */
25#else
26 LD_WAIT_CONFIG = LD_WAIT_SPIN,
27#endif
28 LD_WAIT_SLEEP, /* sleeping locks, mutex_t etc.. */
29
30 LD_WAIT_MAX, /* must be last */
31};
32
33#ifdef CONFIG_LOCKDEP
34
35/*
36 * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
37 * the total number of states... :-(
38 */
39#define XXX_LOCK_USAGE_STATES (1+2*4)
40
41/*
42 * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
43 * cached in the instance of lockdep_map
44 *
45 * Currently main class (subclass == 0) and signle depth subclass
46 * are cached in lockdep_map. This optimization is mainly targeting
47 * on rq->lock. double_rq_lock() acquires this highly competitive with
48 * single depth.
49 */
50#define NR_LOCKDEP_CACHING_CLASSES 2
51
52/*
53 * A lockdep key is associated with each lock object. For static locks we use
54 * the lock address itself as the key. Dynamically allocated lock objects can
55 * have a statically or dynamically allocated key. Dynamically allocated lock
56 * keys must be registered before being used and must be unregistered before
57 * the key memory is freed.
58 */
59struct lockdep_subclass_key {
60 char __one_byte;
61} __attribute__ ((__packed__));
62
63/* hash_entry is used to keep track of dynamically allocated keys. */
64struct lock_class_key {
65 union {
66 struct hlist_node hash_entry;
67 struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
68 };
69};
70
71extern struct lock_class_key __lockdep_no_validate__;
72
73struct lock_trace;
74
75#define LOCKSTAT_POINTS 4
76
77/*
78 * The lock-class itself. The order of the structure members matters.
79 * reinit_class() zeroes the key member and all subsequent members.
80 */
81struct lock_class {
82 /*
83 * class-hash:
84 */
85 struct hlist_node hash_entry;
86
87 /*
88 * Entry in all_lock_classes when in use. Entry in free_lock_classes
89 * when not in use. Instances that are being freed are on one of the
90 * zapped_classes lists.
91 */
92 struct list_head lock_entry;
93
94 /*
95 * These fields represent a directed graph of lock dependencies,
96 * to every node we attach a list of "forward" and a list of
97 * "backward" graph nodes.
98 */
99 struct list_head locks_after, locks_before;
100
101 const struct lockdep_subclass_key *key;
102 unsigned int subclass;
103 unsigned int dep_gen_id;
104
105 /*
106 * IRQ/softirq usage tracking bits:
107 */
108 unsigned long usage_mask;
109 const struct lock_trace *usage_traces[XXX_LOCK_USAGE_STATES];
110
111 /*
112 * Generation counter, when doing certain classes of graph walking,
113 * to ensure that we check one node only once:
114 */
115 int name_version;
116 const char *name;
117
118 short wait_type_inner;
119 short wait_type_outer;
120
121#ifdef CONFIG_LOCK_STAT
122 unsigned long contention_point[LOCKSTAT_POINTS];
123 unsigned long contending_point[LOCKSTAT_POINTS];
124#endif
125} __no_randomize_layout;
126
127#ifdef CONFIG_LOCK_STAT
128struct lock_time {
129 s64 min;
130 s64 max;
131 s64 total;
132 unsigned long nr;
133};
134
135enum bounce_type {
136 bounce_acquired_write,
137 bounce_acquired_read,
138 bounce_contended_write,
139 bounce_contended_read,
140 nr_bounce_types,
141
142 bounce_acquired = bounce_acquired_write,
143 bounce_contended = bounce_contended_write,
144};
145
146struct lock_class_stats {
147 unsigned long contention_point[LOCKSTAT_POINTS];
148 unsigned long contending_point[LOCKSTAT_POINTS];
149 struct lock_time read_waittime;
150 struct lock_time write_waittime;
151 struct lock_time read_holdtime;
152 struct lock_time write_holdtime;
153 unsigned long bounces[nr_bounce_types];
154};
155
156struct lock_class_stats lock_stats(struct lock_class *class);
157void clear_lock_stats(struct lock_class *class);
158#endif
159
160/*
161 * Map the lock object (the lock instance) to the lock-class object.
162 * This is embedded into specific lock instances:
163 */
164struct lockdep_map {
165 struct lock_class_key *key;
166 struct lock_class *class_cache[NR_LOCKDEP_CACHING_CLASSES];
167 const char *name;
168 short wait_type_outer; /* can be taken in this context */
169 short wait_type_inner; /* presents this context */
170#ifdef CONFIG_LOCK_STAT
171 int cpu;
172 unsigned long ip;
173#endif
174};
175
176struct pin_cookie { unsigned int val; };
177
178#else /* !CONFIG_LOCKDEP */
179
180/*
181 * The class key takes no space if lockdep is disabled:
182 */
183struct lock_class_key { };
184
185/*
186 * The lockdep_map takes no space if lockdep is disabled:
187 */
188struct lockdep_map { };
189
190struct pin_cookie { };
191
192#endif /* !LOCKDEP */
193
194#endif /* __LINUX_LOCKDEP_TYPES_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Runtime locking correctness validator
4 *
5 * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
6 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
7 *
8 * see Documentation/locking/lockdep-design.rst for more details.
9 */
10#ifndef __LINUX_LOCKDEP_TYPES_H
11#define __LINUX_LOCKDEP_TYPES_H
12
13#include <linux/types.h>
14
15#define MAX_LOCKDEP_SUBCLASSES 8UL
16
17enum lockdep_wait_type {
18 LD_WAIT_INV = 0, /* not checked, catch all */
19
20 LD_WAIT_FREE, /* wait free, rcu etc.. */
21 LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */
22
23#ifdef CONFIG_PROVE_RAW_LOCK_NESTING
24 LD_WAIT_CONFIG, /* preemptible in PREEMPT_RT, spinlock_t etc.. */
25#else
26 LD_WAIT_CONFIG = LD_WAIT_SPIN,
27#endif
28 LD_WAIT_SLEEP, /* sleeping locks, mutex_t etc.. */
29
30 LD_WAIT_MAX, /* must be last */
31};
32
33enum lockdep_lock_type {
34 LD_LOCK_NORMAL = 0, /* normal, catch all */
35 LD_LOCK_PERCPU, /* percpu */
36 LD_LOCK_WAIT_OVERRIDE, /* annotation */
37 LD_LOCK_MAX,
38};
39
40#ifdef CONFIG_LOCKDEP
41
42/*
43 * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
44 * the total number of states... :-(
45 *
46 * XXX_LOCK_USAGE_STATES is the number of lines in lockdep_states.h, for each
47 * of those we generates 4 states, Additionally we report on USED and USED_READ.
48 */
49#define XXX_LOCK_USAGE_STATES 2
50#define LOCK_TRACE_STATES (XXX_LOCK_USAGE_STATES*4 + 2)
51
52/*
53 * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
54 * cached in the instance of lockdep_map
55 *
56 * Currently main class (subclass == 0) and single depth subclass
57 * are cached in lockdep_map. This optimization is mainly targeting
58 * on rq->lock. double_rq_lock() acquires this highly competitive with
59 * single depth.
60 */
61#define NR_LOCKDEP_CACHING_CLASSES 2
62
63/*
64 * A lockdep key is associated with each lock object. For static locks we use
65 * the lock address itself as the key. Dynamically allocated lock objects can
66 * have a statically or dynamically allocated key. Dynamically allocated lock
67 * keys must be registered before being used and must be unregistered before
68 * the key memory is freed.
69 */
70struct lockdep_subclass_key {
71 char __one_byte;
72} __attribute__ ((__packed__));
73
74/* hash_entry is used to keep track of dynamically allocated keys. */
75struct lock_class_key {
76 union {
77 struct hlist_node hash_entry;
78 struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
79 };
80};
81
82extern struct lock_class_key __lockdep_no_validate__;
83
84struct lock_trace;
85
86#define LOCKSTAT_POINTS 4
87
88struct lockdep_map;
89typedef int (*lock_cmp_fn)(const struct lockdep_map *a,
90 const struct lockdep_map *b);
91typedef void (*lock_print_fn)(const struct lockdep_map *map);
92
93/*
94 * The lock-class itself. The order of the structure members matters.
95 * reinit_class() zeroes the key member and all subsequent members.
96 */
97struct lock_class {
98 /*
99 * class-hash:
100 */
101 struct hlist_node hash_entry;
102
103 /*
104 * Entry in all_lock_classes when in use. Entry in free_lock_classes
105 * when not in use. Instances that are being freed are on one of the
106 * zapped_classes lists.
107 */
108 struct list_head lock_entry;
109
110 /*
111 * These fields represent a directed graph of lock dependencies,
112 * to every node we attach a list of "forward" and a list of
113 * "backward" graph nodes.
114 */
115 struct list_head locks_after, locks_before;
116
117 const struct lockdep_subclass_key *key;
118 lock_cmp_fn cmp_fn;
119 lock_print_fn print_fn;
120
121 unsigned int subclass;
122 unsigned int dep_gen_id;
123
124 /*
125 * IRQ/softirq usage tracking bits:
126 */
127 unsigned long usage_mask;
128 const struct lock_trace *usage_traces[LOCK_TRACE_STATES];
129
130 const char *name;
131 /*
132 * Generation counter, when doing certain classes of graph walking,
133 * to ensure that we check one node only once:
134 */
135 int name_version;
136
137 u8 wait_type_inner;
138 u8 wait_type_outer;
139 u8 lock_type;
140 /* u8 hole; */
141
142#ifdef CONFIG_LOCK_STAT
143 unsigned long contention_point[LOCKSTAT_POINTS];
144 unsigned long contending_point[LOCKSTAT_POINTS];
145#endif
146} __no_randomize_layout;
147
148#ifdef CONFIG_LOCK_STAT
149struct lock_time {
150 s64 min;
151 s64 max;
152 s64 total;
153 unsigned long nr;
154};
155
156enum bounce_type {
157 bounce_acquired_write,
158 bounce_acquired_read,
159 bounce_contended_write,
160 bounce_contended_read,
161 nr_bounce_types,
162
163 bounce_acquired = bounce_acquired_write,
164 bounce_contended = bounce_contended_write,
165};
166
167struct lock_class_stats {
168 unsigned long contention_point[LOCKSTAT_POINTS];
169 unsigned long contending_point[LOCKSTAT_POINTS];
170 struct lock_time read_waittime;
171 struct lock_time write_waittime;
172 struct lock_time read_holdtime;
173 struct lock_time write_holdtime;
174 unsigned long bounces[nr_bounce_types];
175};
176
177struct lock_class_stats lock_stats(struct lock_class *class);
178void clear_lock_stats(struct lock_class *class);
179#endif
180
181/*
182 * Map the lock object (the lock instance) to the lock-class object.
183 * This is embedded into specific lock instances:
184 */
185struct lockdep_map {
186 struct lock_class_key *key;
187 struct lock_class *class_cache[NR_LOCKDEP_CACHING_CLASSES];
188 const char *name;
189 u8 wait_type_outer; /* can be taken in this context */
190 u8 wait_type_inner; /* presents this context */
191 u8 lock_type;
192 /* u8 hole; */
193#ifdef CONFIG_LOCK_STAT
194 int cpu;
195 unsigned long ip;
196#endif
197};
198
199struct pin_cookie { unsigned int val; };
200
201#define MAX_LOCKDEP_KEYS_BITS 13
202#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS)
203#define INITIAL_CHAIN_KEY -1
204
205struct held_lock {
206 /*
207 * One-way hash of the dependency chain up to this point. We
208 * hash the hashes step by step as the dependency chain grows.
209 *
210 * We use it for dependency-caching and we skip detection
211 * passes and dependency-updates if there is a cache-hit, so
212 * it is absolutely critical for 100% coverage of the validator
213 * to have a unique key value for every unique dependency path
214 * that can occur in the system, to make a unique hash value
215 * as likely as possible - hence the 64-bit width.
216 *
217 * The task struct holds the current hash value (initialized
218 * with zero), here we store the previous hash value:
219 */
220 u64 prev_chain_key;
221 unsigned long acquire_ip;
222 struct lockdep_map *instance;
223 struct lockdep_map *nest_lock;
224#ifdef CONFIG_LOCK_STAT
225 u64 waittime_stamp;
226 u64 holdtime_stamp;
227#endif
228 /*
229 * class_idx is zero-indexed; it points to the element in
230 * lock_classes this held lock instance belongs to. class_idx is in
231 * the range from 0 to (MAX_LOCKDEP_KEYS-1) inclusive.
232 */
233 unsigned int class_idx:MAX_LOCKDEP_KEYS_BITS;
234 /*
235 * The lock-stack is unified in that the lock chains of interrupt
236 * contexts nest ontop of process context chains, but we 'separate'
237 * the hashes by starting with 0 if we cross into an interrupt
238 * context, and we also keep do not add cross-context lock
239 * dependencies - the lock usage graph walking covers that area
240 * anyway, and we'd just unnecessarily increase the number of
241 * dependencies otherwise. [Note: hardirq and softirq contexts
242 * are separated from each other too.]
243 *
244 * The following field is used to detect when we cross into an
245 * interrupt context:
246 */
247 unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
248 unsigned int trylock:1; /* 16 bits */
249
250 unsigned int read:2; /* see lock_acquire() comment */
251 unsigned int check:1; /* see lock_acquire() comment */
252 unsigned int hardirqs_off:1;
253 unsigned int sync:1;
254 unsigned int references:11; /* 32 bits */
255 unsigned int pin_count;
256};
257
258#else /* !CONFIG_LOCKDEP */
259
260/*
261 * The class key takes no space if lockdep is disabled:
262 */
263struct lock_class_key { };
264
265/*
266 * The lockdep_map takes no space if lockdep is disabled:
267 */
268struct lockdep_map { };
269
270struct pin_cookie { };
271
272#endif /* !LOCKDEP */
273
274#endif /* __LINUX_LOCKDEP_TYPES_H */