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_USED_READ, 23 LOCK_USAGE_STATES, 24 }; 25 26 /* states after LOCK_USED_READ are not traced and printed */ 27 static_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 38 enum { 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 50 #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE | 51 static const unsigned long LOCKF_ENABLED_IRQ = 52 #include "lockdep_states.h" 53 0; 54 #undef LOCKDEP_STATE 55 56 #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE | 57 static const unsigned long LOCKF_USED_IN_IRQ = 58 #include "lockdep_states.h" 59 0; 60 #undef LOCKDEP_STATE 61 62 #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE##_READ | 63 static const unsigned long LOCKF_ENABLED_IRQ_READ = 64 #include "lockdep_states.h" 65 0; 66 #undef LOCKDEP_STATE 67 68 #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE##_READ | 69 static const unsigned long LOCKF_USED_IN_IRQ_READ = 70 #include "lockdep_states.h" 71 0; 72 #undef LOCKDEP_STATE 73 74 #define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ) 75 #define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ) 76 77 #define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ) 78 #define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_READ) 79 80 /* 81 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text, 82 * .data and .bss to fit in required 32MB limit for the kernel. With 83 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems. 84 * So, reduce the static allocations for lockdeps related structures so that 85 * everything fits in current required size limit. 86 */ 87 #ifdef CONFIG_LOCKDEP_SMALL 88 /* 89 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies 90 * we track. 91 * 92 * We use the per-lock dependency maps in two ways: we grow it by adding 93 * every to-be-taken lock to all currently held lock's own dependency 94 * table (if it's not there yet), and we check it for lock order 95 * conflicts and deadlocks. 96 */ 97 #define MAX_LOCKDEP_ENTRIES 16384UL 98 #define MAX_LOCKDEP_CHAINS_BITS 15 99 #define MAX_STACK_TRACE_ENTRIES 262144UL 100 #define STACK_TRACE_HASH_SIZE 8192 101 #else 102 #define MAX_LOCKDEP_ENTRIES (1UL << CONFIG_LOCKDEP_BITS) 103 104 #define MAX_LOCKDEP_CHAINS_BITS CONFIG_LOCKDEP_CHAINS_BITS 105 106 /* 107 * Stack-trace: tightly packed array of stack backtrace 108 * addresses. Protected by the hash_lock. 109 */ 110 #define MAX_STACK_TRACE_ENTRIES (1UL << CONFIG_LOCKDEP_STACK_TRACE_BITS) 111 #define STACK_TRACE_HASH_SIZE (1 << CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS) 112 #endif 113 114 /* 115 * Bit definitions for lock_chain.irq_context 116 */ 117 #define LOCK_CHAIN_SOFTIRQ_CONTEXT (1 << 0) 118 #define LOCK_CHAIN_HARDIRQ_CONTEXT (1 << 1) 119 120 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS) 121 122 #define AVG_LOCKDEP_CHAIN_DEPTH 5 123 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS * AVG_LOCKDEP_CHAIN_DEPTH) 124 125 extern struct lock_chain lock_chains[]; 126 127 #define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1) 128 129 extern void get_usage_chars(struct lock_class *class, 130 char usage[LOCK_USAGE_CHARS]); 131 132 extern const char *__get_key_name(const struct lockdep_subclass_key *key, 133 char *str); 134 135 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); 136 137 extern unsigned long nr_lock_classes; 138 extern unsigned long nr_zapped_classes; 139 extern unsigned long nr_zapped_lock_chains; 140 extern unsigned long nr_list_entries; 141 long lockdep_next_lockchain(long i); 142 unsigned long lock_chain_count(void); 143 extern unsigned long nr_stack_trace_entries; 144 145 extern unsigned int nr_hardirq_chains; 146 extern unsigned int nr_softirq_chains; 147 extern unsigned int nr_process_chains; 148 extern unsigned int nr_free_chain_hlocks; 149 extern unsigned int nr_lost_chain_hlocks; 150 extern unsigned int nr_large_chain_blocks; 151 152 extern unsigned int max_lockdep_depth; 153 extern unsigned int max_bfs_queue_depth; 154 extern unsigned long max_lock_class_idx; 155 156 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; 157 extern unsigned long lock_classes_in_use[]; 158 159 #ifdef CONFIG_PROVE_LOCKING 160 extern unsigned long lockdep_count_forward_deps(struct lock_class *); 161 extern unsigned long lockdep_count_backward_deps(struct lock_class *); 162 #ifdef CONFIG_TRACE_IRQFLAGS 163 u64 lockdep_stack_trace_count(void); 164 u64 lockdep_stack_hash_count(void); 165 #endif 166 #else 167 static inline unsigned long 168 lockdep_count_forward_deps(struct lock_class *class) 169 { 170 return 0; 171 } 172 static inline unsigned long 173 lockdep_count_backward_deps(struct lock_class *class) 174 { 175 return 0; 176 } 177 #endif 178 179 #ifdef CONFIG_DEBUG_LOCKDEP 180 181 #include <asm/local.h> 182 /* 183 * Various lockdep statistics. 184 * We want them per cpu as they are often accessed in fast path 185 * and we want to avoid too much cache bouncing. 186 */ 187 struct lockdep_stats { 188 unsigned long chain_lookup_hits; 189 unsigned int chain_lookup_misses; 190 unsigned long hardirqs_on_events; 191 unsigned long hardirqs_off_events; 192 unsigned long redundant_hardirqs_on; 193 unsigned long redundant_hardirqs_off; 194 unsigned long softirqs_on_events; 195 unsigned long softirqs_off_events; 196 unsigned long redundant_softirqs_on; 197 unsigned long redundant_softirqs_off; 198 int nr_unused_locks; 199 unsigned int nr_redundant_checks; 200 unsigned int nr_redundant; 201 unsigned int nr_cyclic_checks; 202 unsigned int nr_find_usage_forwards_checks; 203 unsigned int nr_find_usage_backwards_checks; 204 205 /* 206 * Per lock class locking operation stat counts 207 */ 208 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS]; 209 }; 210 211 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats); 212 213 #define __debug_atomic_inc(ptr) \ 214 this_cpu_inc(lockdep_stats.ptr); 215 216 #define debug_atomic_inc(ptr) { \ 217 WARN_ON_ONCE(!irqs_disabled()); \ 218 __this_cpu_inc(lockdep_stats.ptr); \ 219 } 220 221 #define debug_atomic_dec(ptr) { \ 222 WARN_ON_ONCE(!irqs_disabled()); \ 223 __this_cpu_dec(lockdep_stats.ptr); \ 224 } 225 226 #define debug_atomic_read(ptr) ({ \ 227 struct lockdep_stats *__cpu_lockdep_stats; \ 228 unsigned long long __total = 0; \ 229 int __cpu; \ 230 for_each_possible_cpu(__cpu) { \ 231 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \ 232 __total += __cpu_lockdep_stats->ptr; \ 233 } \ 234 __total; \ 235 }) 236 237 static inline void debug_class_ops_inc(struct lock_class *class) 238 { 239 int idx; 240 241 idx = class - lock_classes; 242 __debug_atomic_inc(lock_class_ops[idx]); 243 } 244 245 static inline unsigned long debug_class_ops_read(struct lock_class *class) 246 { 247 int idx, cpu; 248 unsigned long ops = 0; 249 250 idx = class - lock_classes; 251 for_each_possible_cpu(cpu) 252 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu); 253 return ops; 254 } 255 256 #else 257 # define __debug_atomic_inc(ptr) do { } while (0) 258 # define debug_atomic_inc(ptr) do { } while (0) 259 # define debug_atomic_dec(ptr) do { } while (0) 260 # define debug_atomic_read(ptr) 0 261 # define debug_class_ops_inc(ptr) do { } while (0) 262 #endif 263