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 LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ) 46 #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ) 47 48 #define LOCKF_ENABLED_IRQ_READ \ 49 (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ) 50 #define LOCKF_USED_IN_IRQ_READ \ 51 (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ) 52 53 /* 54 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text, 55 * .data and .bss to fit in required 32MB limit for the kernel. With 56 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems. 57 * So, reduce the static allocations for lockdeps related structures so that 58 * everything fits in current required size limit. 59 */ 60 #ifdef CONFIG_LOCKDEP_SMALL 61 /* 62 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies 63 * we track. 64 * 65 * We use the per-lock dependency maps in two ways: we grow it by adding 66 * every to-be-taken lock to all currently held lock's own dependency 67 * table (if it's not there yet), and we check it for lock order 68 * conflicts and deadlocks. 69 */ 70 #define MAX_LOCKDEP_ENTRIES 16384UL 71 #define MAX_LOCKDEP_CHAINS_BITS 15 72 #define MAX_STACK_TRACE_ENTRIES 262144UL 73 #else 74 #define MAX_LOCKDEP_ENTRIES 32768UL 75 76 #define MAX_LOCKDEP_CHAINS_BITS 16 77 78 /* 79 * Stack-trace: tightly packed array of stack backtrace 80 * addresses. Protected by the hash_lock. 81 */ 82 #define MAX_STACK_TRACE_ENTRIES 524288UL 83 #endif 84 85 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS) 86 87 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5) 88 89 extern struct list_head all_lock_classes; 90 extern struct lock_chain lock_chains[]; 91 92 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2) 93 94 extern void get_usage_chars(struct lock_class *class, 95 char usage[LOCK_USAGE_CHARS]); 96 97 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); 98 99 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); 100 101 extern unsigned long nr_lock_classes; 102 extern unsigned long nr_list_entries; 103 long lockdep_next_lockchain(long i); 104 unsigned long lock_chain_count(void); 105 extern int nr_chain_hlocks; 106 extern unsigned long nr_stack_trace_entries; 107 108 extern unsigned int nr_hardirq_chains; 109 extern unsigned int nr_softirq_chains; 110 extern unsigned int nr_process_chains; 111 extern unsigned int max_lockdep_depth; 112 extern unsigned int max_recursion_depth; 113 114 extern unsigned int max_bfs_queue_depth; 115 116 #ifdef CONFIG_PROVE_LOCKING 117 extern unsigned long lockdep_count_forward_deps(struct lock_class *); 118 extern unsigned long lockdep_count_backward_deps(struct lock_class *); 119 #else 120 static inline unsigned long 121 lockdep_count_forward_deps(struct lock_class *class) 122 { 123 return 0; 124 } 125 static inline unsigned long 126 lockdep_count_backward_deps(struct lock_class *class) 127 { 128 return 0; 129 } 130 #endif 131 132 #ifdef CONFIG_DEBUG_LOCKDEP 133 134 #include <asm/local.h> 135 /* 136 * Various lockdep statistics. 137 * We want them per cpu as they are often accessed in fast path 138 * and we want to avoid too much cache bouncing. 139 */ 140 struct lockdep_stats { 141 int chain_lookup_hits; 142 int chain_lookup_misses; 143 int hardirqs_on_events; 144 int hardirqs_off_events; 145 int redundant_hardirqs_on; 146 int redundant_hardirqs_off; 147 int softirqs_on_events; 148 int softirqs_off_events; 149 int redundant_softirqs_on; 150 int redundant_softirqs_off; 151 int nr_unused_locks; 152 int nr_redundant_checks; 153 int nr_redundant; 154 int nr_cyclic_checks; 155 int nr_cyclic_check_recursions; 156 int nr_find_usage_forwards_checks; 157 int nr_find_usage_forwards_recursions; 158 int nr_find_usage_backwards_checks; 159 int nr_find_usage_backwards_recursions; 160 161 /* 162 * Per lock class locking operation stat counts 163 */ 164 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS]; 165 }; 166 167 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats); 168 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; 169 170 #define __debug_atomic_inc(ptr) \ 171 this_cpu_inc(lockdep_stats.ptr); 172 173 #define debug_atomic_inc(ptr) { \ 174 WARN_ON_ONCE(!irqs_disabled()); \ 175 __this_cpu_inc(lockdep_stats.ptr); \ 176 } 177 178 #define debug_atomic_dec(ptr) { \ 179 WARN_ON_ONCE(!irqs_disabled()); \ 180 __this_cpu_dec(lockdep_stats.ptr); \ 181 } 182 183 #define debug_atomic_read(ptr) ({ \ 184 struct lockdep_stats *__cpu_lockdep_stats; \ 185 unsigned long long __total = 0; \ 186 int __cpu; \ 187 for_each_possible_cpu(__cpu) { \ 188 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \ 189 __total += __cpu_lockdep_stats->ptr; \ 190 } \ 191 __total; \ 192 }) 193 194 static inline void debug_class_ops_inc(struct lock_class *class) 195 { 196 int idx; 197 198 idx = class - lock_classes; 199 __debug_atomic_inc(lock_class_ops[idx]); 200 } 201 202 static inline unsigned long debug_class_ops_read(struct lock_class *class) 203 { 204 int idx, cpu; 205 unsigned long ops = 0; 206 207 idx = class - lock_classes; 208 for_each_possible_cpu(cpu) 209 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu); 210 return ops; 211 } 212 213 #else 214 # define __debug_atomic_inc(ptr) do { } while (0) 215 # define debug_atomic_inc(ptr) do { } while (0) 216 # define debug_atomic_dec(ptr) do { } while (0) 217 # define debug_atomic_read(ptr) 0 218 # define debug_class_ops_inc(ptr) do { } while (0) 219 #endif 220