kernel/locking/lockdep_internals.h

   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 LOCKDEP_STATE(__STATE)  LOCKF_ENABLED_##__STATE |
  46 static const unsigned long LOCKF_ENABLED_IRQ =
  47 #include "lockdep_states.h"
  48         0;
  49 #undef LOCKDEP_STATE
  50
  51 #define LOCKDEP_STATE(__STATE)  LOCKF_USED_IN_##__STATE |
  52 static const unsigned long LOCKF_USED_IN_IRQ =
  53 #include "lockdep_states.h"
  54         0;
  55 #undef LOCKDEP_STATE
  56
  57 #define LOCKDEP_STATE(__STATE)  LOCKF_ENABLED_##__STATE##_READ |
  58 static const unsigned long LOCKF_ENABLED_IRQ_READ =
  59 #include "lockdep_states.h"
  60         0;
  61 #undef LOCKDEP_STATE
  62
  63 #define LOCKDEP_STATE(__STATE)  LOCKF_USED_IN_##__STATE##_READ |
  64 static const unsigned long LOCKF_USED_IN_IRQ_READ =
  65 #include "lockdep_states.h"
  66         0;
  67 #undef LOCKDEP_STATE
  68
  69 #define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ)
  70 #define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ)
  71
  72 #define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ)
  73 #define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_READ)
  74
  75 /*
  76  * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
  77  * .data and .bss to fit in required 32MB limit for the kernel. With
  78  * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
  79  * So, reduce the static allocations for lockdeps related structures so that
  80  * everything fits in current required size limit.
  81  */
  82 #ifdef CONFIG_LOCKDEP_SMALL
  83 /*
  84  * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
  85  * we track.
  86  *
  87  * We use the per-lock dependency maps in two ways: we grow it by adding
  88  * every to-be-taken lock to all currently held lock's own dependency
  89  * table (if it's not there yet), and we check it for lock order
  90  * conflicts and deadlocks.
  91  */
  92 #define MAX_LOCKDEP_ENTRIES     16384UL
  93 #define MAX_LOCKDEP_CHAINS_BITS 15
  94 #define MAX_STACK_TRACE_ENTRIES 262144UL
  95 #define STACK_TRACE_HASH_SIZE   8192
  96 #else
  97 #define MAX_LOCKDEP_ENTRIES     32768UL
  98
  99 #define MAX_LOCKDEP_CHAINS_BITS 16
 100
 101 /*
 102  * Stack-trace: tightly packed array of stack backtrace
 103  * addresses. Protected by the hash_lock.
 104  */
 105 #define MAX_STACK_TRACE_ENTRIES 524288UL
 106 #define STACK_TRACE_HASH_SIZE   16384
 107 #endif
 108
 109 /*
 110  * Bit definitions for lock_chain.irq_context
 111  */
 112 #define LOCK_CHAIN_SOFTIRQ_CONTEXT      (1 << 0)
 113 #define LOCK_CHAIN_HARDIRQ_CONTEXT      (1 << 1)
 114
 115 #define MAX_LOCKDEP_CHAINS      (1UL << MAX_LOCKDEP_CHAINS_BITS)
 116
 117 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
 118
 119 extern struct list_head all_lock_classes;
 120 extern struct lock_chain lock_chains[];
 121
 122 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
 123
 124 extern void get_usage_chars(struct lock_class *class,
 125                             char usage[LOCK_USAGE_CHARS]);
 126
 127 extern const char *__get_key_name(const struct lockdep_subclass_key *key,
 128                                   char *str);
 129
 130 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
 131
 132 extern unsigned long nr_lock_classes;
 133 extern unsigned long nr_zapped_classes;
 134 extern unsigned long nr_zapped_lock_chains;
 135 extern unsigned long nr_list_entries;
 136 long lockdep_next_lockchain(long i);
 137 unsigned long lock_chain_count(void);
 138 extern unsigned long nr_stack_trace_entries;
 139
 140 extern unsigned int nr_hardirq_chains;
 141 extern unsigned int nr_softirq_chains;
 142 extern unsigned int nr_process_chains;
 143 extern unsigned int nr_free_chain_hlocks;
 144 extern unsigned int nr_lost_chain_hlocks;
 145 extern unsigned int nr_large_chain_blocks;
 146
 147 extern unsigned int max_lockdep_depth;
 148 extern unsigned int max_bfs_queue_depth;
 149
 150 #ifdef CONFIG_PROVE_LOCKING
 151 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
 152 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
 153 #ifdef CONFIG_TRACE_IRQFLAGS
 154 u64 lockdep_stack_trace_count(void);
 155 u64 lockdep_stack_hash_count(void);
 156 #endif
 157 #else
 158 static inline unsigned long
 159 lockdep_count_forward_deps(struct lock_class *class)
 160 {
 161         return 0;
 162 }
 163 static inline unsigned long
 164 lockdep_count_backward_deps(struct lock_class *class)
 165 {
 166         return 0;
 167 }
 168 #endif
 169
 170 #ifdef CONFIG_DEBUG_LOCKDEP
 171
 172 #include <asm/local.h>
 173 /*
 174  * Various lockdep statistics.
 175  * We want them per cpu as they are often accessed in fast path
 176  * and we want to avoid too much cache bouncing.
 177  */
 178 struct lockdep_stats {
 179         unsigned long  chain_lookup_hits;
 180         unsigned int   chain_lookup_misses;
 181         unsigned long  hardirqs_on_events;
 182         unsigned long  hardirqs_off_events;
 183         unsigned long  redundant_hardirqs_on;
 184         unsigned long  redundant_hardirqs_off;
 185         unsigned long  softirqs_on_events;
 186         unsigned long  softirqs_off_events;
 187         unsigned long  redundant_softirqs_on;
 188         unsigned long  redundant_softirqs_off;
 189         int            nr_unused_locks;
 190         unsigned int   nr_redundant_checks;
 191         unsigned int   nr_redundant;
 192         unsigned int   nr_cyclic_checks;
 193         unsigned int   nr_find_usage_forwards_checks;
 194         unsigned int   nr_find_usage_backwards_checks;
 195
 196         /*
 197          * Per lock class locking operation stat counts
 198          */
 199         unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
 200 };
 201
 202 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
 203 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 204
 205 #define __debug_atomic_inc(ptr)                                 \
 206         this_cpu_inc(lockdep_stats.ptr);
 207
 208 #define debug_atomic_inc(ptr)                   {               \
 209         WARN_ON_ONCE(!irqs_disabled());                         \
 210         __this_cpu_inc(lockdep_stats.ptr);                      \
 211 }
 212
 213 #define debug_atomic_dec(ptr)                   {               \
 214         WARN_ON_ONCE(!irqs_disabled());                         \
 215         __this_cpu_dec(lockdep_stats.ptr);                      \
 216 }
 217
 218 #define debug_atomic_read(ptr)          ({                              \
 219         struct lockdep_stats *__cpu_lockdep_stats;                      \
 220         unsigned long long __total = 0;                                 \
 221         int __cpu;                                                      \
 222         for_each_possible_cpu(__cpu) {                                  \
 223                 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);   \
 224                 __total += __cpu_lockdep_stats->ptr;                    \
 225         }                                                               \
 226         __total;                                                        \
 227 })
 228
 229 static inline void debug_class_ops_inc(struct lock_class *class)
 230 {
 231         int idx;
 232
 233         idx = class - lock_classes;
 234         __debug_atomic_inc(lock_class_ops[idx]);
 235 }
 236
 237 static inline unsigned long debug_class_ops_read(struct lock_class *class)
 238 {
 239         int idx, cpu;
 240         unsigned long ops = 0;
 241
 242         idx = class - lock_classes;
 243         for_each_possible_cpu(cpu)
 244                 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
 245         return ops;
 246 }
 247
 248 #else
 249 # define __debug_atomic_inc(ptr)        do { } while (0)
 250 # define debug_atomic_inc(ptr)          do { } while (0)
 251 # define debug_atomic_dec(ptr)          do { } while (0)
 252 # define debug_atomic_read(ptr)         0
 253 # define debug_class_ops_inc(ptr)       do { } while (0)
 254 #endif