| 1 | /* |
| 2 | * kernel/lockdep_internals.h |
| 3 | * |
| 4 | * Runtime locking correctness validator |
| 5 | * |
| 6 | * lockdep subsystem internal functions and variables. |
| 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * Lock-class usage-state bits: |
| 11 | */ |
| 12 | enum lock_usage_bit { |
| 13 | #define LOCKDEP_STATE(__STATE) \ |
| 14 | LOCK_USED_IN_##__STATE, \ |
| 15 | LOCK_USED_IN_##__STATE##_READ, \ |
| 16 | LOCK_ENABLED_##__STATE, \ |
| 17 | LOCK_ENABLED_##__STATE##_READ, |
| 18 | #include "lockdep_states.h" |
| 19 | #undef LOCKDEP_STATE |
| 20 | LOCK_USED, |
| 21 | LOCK_USAGE_STATES |
| 22 | }; |
| 23 | |
| 24 | /* |
| 25 | * Usage-state bitmasks: |
| 26 | */ |
| 27 | #define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE), |
| 28 | |
| 29 | enum { |
| 30 | #define LOCKDEP_STATE(__STATE) \ |
| 31 | __LOCKF(USED_IN_##__STATE) \ |
| 32 | __LOCKF(USED_IN_##__STATE##_READ) \ |
| 33 | __LOCKF(ENABLED_##__STATE) \ |
| 34 | __LOCKF(ENABLED_##__STATE##_READ) |
| 35 | #include "lockdep_states.h" |
| 36 | #undef LOCKDEP_STATE |
| 37 | __LOCKF(USED) |
| 38 | }; |
| 39 | |
| 40 | #define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ) |
| 41 | #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ) |
| 42 | |
| 43 | #define LOCKF_ENABLED_IRQ_READ \ |
| 44 | (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ) |
| 45 | #define LOCKF_USED_IN_IRQ_READ \ |
| 46 | (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ) |
| 47 | |
| 48 | /* |
| 49 | * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies |
| 50 | * we track. |
| 51 | * |
| 52 | * We use the per-lock dependency maps in two ways: we grow it by adding |
| 53 | * every to-be-taken lock to all currently held lock's own dependency |
| 54 | * table (if it's not there yet), and we check it for lock order |
| 55 | * conflicts and deadlocks. |
| 56 | */ |
| 57 | #define MAX_LOCKDEP_ENTRIES 16384UL |
| 58 | |
| 59 | #define MAX_LOCKDEP_CHAINS_BITS 15 |
| 60 | #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS) |
| 61 | |
| 62 | #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5) |
| 63 | |
| 64 | /* |
| 65 | * Stack-trace: tightly packed array of stack backtrace |
| 66 | * addresses. Protected by the hash_lock. |
| 67 | */ |
| 68 | #define MAX_STACK_TRACE_ENTRIES 262144UL |
| 69 | |
| 70 | extern struct list_head all_lock_classes; |
| 71 | extern struct lock_chain lock_chains[]; |
| 72 | |
| 73 | #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2) |
| 74 | |
| 75 | extern void get_usage_chars(struct lock_class *class, |
| 76 | char usage[LOCK_USAGE_CHARS]); |
| 77 | |
| 78 | extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); |
| 79 | |
| 80 | struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); |
| 81 | |
| 82 | extern unsigned long nr_lock_classes; |
| 83 | extern unsigned long nr_list_entries; |
| 84 | extern unsigned long nr_lock_chains; |
| 85 | extern int nr_chain_hlocks; |
| 86 | extern unsigned long nr_stack_trace_entries; |
| 87 | |
| 88 | extern unsigned int nr_hardirq_chains; |
| 89 | extern unsigned int nr_softirq_chains; |
| 90 | extern unsigned int nr_process_chains; |
| 91 | extern unsigned int max_lockdep_depth; |
| 92 | extern unsigned int max_recursion_depth; |
| 93 | |
| 94 | #ifdef CONFIG_PROVE_LOCKING |
| 95 | extern unsigned long lockdep_count_forward_deps(struct lock_class *); |
| 96 | extern unsigned long lockdep_count_backward_deps(struct lock_class *); |
| 97 | #else |
| 98 | static inline unsigned long |
| 99 | lockdep_count_forward_deps(struct lock_class *class) |
| 100 | { |
| 101 | return 0; |
| 102 | } |
| 103 | static inline unsigned long |
| 104 | lockdep_count_backward_deps(struct lock_class *class) |
| 105 | { |
| 106 | return 0; |
| 107 | } |
| 108 | #endif |
| 109 | |
| 110 | #ifdef CONFIG_DEBUG_LOCKDEP |
| 111 | /* |
| 112 | * Various lockdep statistics: |
| 113 | */ |
| 114 | extern atomic_t chain_lookup_hits; |
| 115 | extern atomic_t chain_lookup_misses; |
| 116 | extern atomic_t hardirqs_on_events; |
| 117 | extern atomic_t hardirqs_off_events; |
| 118 | extern atomic_t redundant_hardirqs_on; |
| 119 | extern atomic_t redundant_hardirqs_off; |
| 120 | extern atomic_t softirqs_on_events; |
| 121 | extern atomic_t softirqs_off_events; |
| 122 | extern atomic_t redundant_softirqs_on; |
| 123 | extern atomic_t redundant_softirqs_off; |
| 124 | extern atomic_t nr_unused_locks; |
| 125 | extern atomic_t nr_cyclic_checks; |
| 126 | extern atomic_t nr_cyclic_check_recursions; |
| 127 | extern atomic_t nr_find_usage_forwards_checks; |
| 128 | extern atomic_t nr_find_usage_forwards_recursions; |
| 129 | extern atomic_t nr_find_usage_backwards_checks; |
| 130 | extern atomic_t nr_find_usage_backwards_recursions; |
| 131 | # define debug_atomic_inc(ptr) atomic_inc(ptr) |
| 132 | # define debug_atomic_dec(ptr) atomic_dec(ptr) |
| 133 | # define debug_atomic_read(ptr) atomic_read(ptr) |
| 134 | #else |
| 135 | # define debug_atomic_inc(ptr) do { } while (0) |
| 136 | # define debug_atomic_dec(ptr) do { } while (0) |
| 137 | # define debug_atomic_read(ptr) 0 |
| 138 | #endif |
| 139 | |
| 140 | |
| 141 | extern unsigned long nr_list_entries; |
| 142 | extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES]; |
| 143 | extern unsigned long bfs_accessed[]; |
| 144 | |
| 145 | /*For good efficiency of modular, we use power of 2*/ |
| 146 | #define MAX_CIRCULAR_QUE_SIZE 4096UL |
| 147 | |
| 148 | /* The circular_queue and helpers is used to implement the |
| 149 | * breadth-first search(BFS)algorithem, by which we can build |
| 150 | * the shortest path from the next lock to be acquired to the |
| 151 | * previous held lock if there is a circular between them. |
| 152 | * */ |
| 153 | struct circular_queue{ |
| 154 | unsigned long element[MAX_CIRCULAR_QUE_SIZE]; |
| 155 | unsigned int front, rear; |
| 156 | }; |
| 157 | |
| 158 | static inline void __cq_init(struct circular_queue *cq) |
| 159 | { |
| 160 | cq->front = cq->rear = 0; |
| 161 | bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES); |
| 162 | } |
| 163 | |
| 164 | static inline int __cq_empty(struct circular_queue *cq) |
| 165 | { |
| 166 | return (cq->front == cq->rear); |
| 167 | } |
| 168 | |
| 169 | static inline int __cq_full(struct circular_queue *cq) |
| 170 | { |
| 171 | return ((cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1)) == cq->front; |
| 172 | } |
| 173 | |
| 174 | static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem) |
| 175 | { |
| 176 | if (__cq_full(cq)) |
| 177 | return -1; |
| 178 | |
| 179 | cq->element[cq->rear] = elem; |
| 180 | cq->rear = (cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1); |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem) |
| 185 | { |
| 186 | if (__cq_empty(cq)) |
| 187 | return -1; |
| 188 | |
| 189 | *elem = cq->element[cq->front]; |
| 190 | cq->front = (cq->front + 1)&(MAX_CIRCULAR_QUE_SIZE-1); |
| 191 | return 0; |
| 192 | } |
| 193 | |
| 194 | static inline int __cq_get_elem_count(struct circular_queue *cq) |
| 195 | { |
| 196 | return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1); |
| 197 | } |
| 198 | |
| 199 | static inline void mark_lock_accessed(struct lock_list *lock, |
| 200 | struct lock_list *parent) |
| 201 | { |
| 202 | unsigned long nr; |
| 203 | nr = lock - list_entries; |
| 204 | WARN_ON(nr >= nr_list_entries); |
| 205 | lock->parent = parent; |
| 206 | set_bit(nr, bfs_accessed); |
| 207 | } |
| 208 | |
| 209 | static inline unsigned long lock_accessed(struct lock_list *lock) |
| 210 | { |
| 211 | unsigned long nr; |
| 212 | nr = lock - list_entries; |
| 213 | WARN_ON(nr >= nr_list_entries); |
| 214 | return test_bit(nr, bfs_accessed); |
| 215 | } |
| 216 | |
| 217 | static inline struct lock_list *get_lock_parent(struct lock_list *child) |
| 218 | { |
| 219 | return child->parent; |
| 220 | } |
| 221 | |
| 222 | static inline unsigned long get_lock_depth(struct lock_list *child) |
| 223 | { |
| 224 | unsigned long depth = 0; |
| 225 | struct lock_list *parent; |
| 226 | |
| 227 | while ((parent = get_lock_parent(child))) { |
| 228 | child = parent; |
| 229 | depth++; |
| 230 | } |
| 231 | return depth; |
| 232 | } |