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 17 enum 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 33 enum 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 */ 70 struct lockdep_subclass_key { 71 char __one_byte; 72 } __attribute__ ((__packed__)); 73 74 /* hash_entry is used to keep track of dynamically allocated keys. */ 75 struct lock_class_key { 76 union { 77 struct hlist_node hash_entry; 78 struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES]; 79 }; 80 }; 81 82 extern struct lock_class_key __lockdep_no_validate__; 83 84 struct lock_trace; 85 86 #define LOCKSTAT_POINTS 4 87 88 struct lockdep_map; 89 typedef int (*lock_cmp_fn)(const struct lockdep_map *a, 90 const struct lockdep_map *b); 91 typedef 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 */ 97 struct 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 149 struct lock_time { 150 s64 min; 151 s64 max; 152 s64 total; 153 unsigned long nr; 154 }; 155 156 enum 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 }; 166 167 struct 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 }; 176 177 struct lock_class_stats lock_stats(struct lock_class *class); 178 void 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 */ 185 struct 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 }; 198 199 struct 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 -1 204 205 struct 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 */ 263 struct lock_class_key { }; 264 265 /* 266 * The lockdep_map takes no space if lockdep is disabled: 267 */ 268 struct lockdep_map { }; 269 270 struct pin_cookie { }; 271 272 #endif /* !LOCKDEP */ 273 274 #endif /* __LINUX_LOCKDEP_TYPES_H */ 275