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 #else
  96 #define MAX_LOCKDEP_ENTRIES     32768UL
  97
  98 #define MAX_LOCKDEP_CHAINS_BITS 16
  99
 100 /*
 101  * Stack-trace: tightly packed array of stack backtrace
 102  * addresses. Protected by the hash_lock.
 103  */
 104 #define MAX_STACK_TRACE_ENTRIES 524288UL
 105 #endif
 106
 107 #define MAX_LOCKDEP_CHAINS      (1UL << MAX_LOCKDEP_CHAINS_BITS)
 108
 109 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
 110
 111 extern struct list_head all_lock_classes;
 112 extern struct lock_chain lock_chains[];
 113
 114 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
 115
 116 extern void get_usage_chars(struct lock_class *class,
 117                             char usage[LOCK_USAGE_CHARS]);
 118
 119 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
 120
 121 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
 122
 123 extern unsigned long nr_lock_classes;
 124 extern unsigned long nr_list_entries;
 125 long lockdep_next_lockchain(long i);
 126 unsigned long lock_chain_count(void);
 127 extern int nr_chain_hlocks;
 128 extern unsigned long nr_stack_trace_entries;
 129
 130 extern unsigned int nr_hardirq_chains;
 131 extern unsigned int nr_softirq_chains;
 132 extern unsigned int nr_process_chains;
 133 extern unsigned int max_lockdep_depth;
 134
 135 extern unsigned int max_bfs_queue_depth;
 136
 137 #ifdef CONFIG_PROVE_LOCKING
 138 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
 139 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
 140 #else
 141 static inline unsigned long
 142 lockdep_count_forward_deps(struct lock_class *class)
 143 {
 144         return 0;
 145 }
 146 static inline unsigned long
 147 lockdep_count_backward_deps(struct lock_class *class)
 148 {
 149         return 0;
 150 }
 151 #endif
 152
 153 #ifdef CONFIG_DEBUG_LOCKDEP
 154
 155 #include <asm/local.h>
 156 /*
 157  * Various lockdep statistics.
 158  * We want them per cpu as they are often accessed in fast path
 159  * and we want to avoid too much cache bouncing.
 160  */
 161 struct lockdep_stats {
 162         unsigned long  chain_lookup_hits;
 163         unsigned int   chain_lookup_misses;
 164         unsigned long  hardirqs_on_events;
 165         unsigned long  hardirqs_off_events;
 166         unsigned long  redundant_hardirqs_on;
 167         unsigned long  redundant_hardirqs_off;
 168         unsigned long  softirqs_on_events;
 169         unsigned long  softirqs_off_events;
 170         unsigned long  redundant_softirqs_on;
 171         unsigned long  redundant_softirqs_off;
 172         int            nr_unused_locks;
 173         unsigned int   nr_redundant_checks;
 174         unsigned int   nr_redundant;
 175         unsigned int   nr_cyclic_checks;
 176         unsigned int   nr_find_usage_forwards_checks;
 177         unsigned int   nr_find_usage_backwards_checks;
 178
 179         /*
 180          * Per lock class locking operation stat counts
 181          */
 182         unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
 183 };
 184
 185 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
 186 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 187
 188 #define __debug_atomic_inc(ptr)                                 \
 189         this_cpu_inc(lockdep_stats.ptr);
 190
 191 #define debug_atomic_inc(ptr)                   {               \
 192         WARN_ON_ONCE(!irqs_disabled());                         \
 193         __this_cpu_inc(lockdep_stats.ptr);                      \
 194 }
 195
 196 #define debug_atomic_dec(ptr)                   {               \
 197         WARN_ON_ONCE(!irqs_disabled());                         \
 198         __this_cpu_dec(lockdep_stats.ptr);                      \
 199 }
 200
 201 #define debug_atomic_read(ptr)          ({                              \
 202         struct lockdep_stats *__cpu_lockdep_stats;                      \
 203         unsigned long long __total = 0;                                 \
 204         int __cpu;                                                      \
 205         for_each_possible_cpu(__cpu) {                                  \
 206                 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);   \
 207                 __total += __cpu_lockdep_stats->ptr;                    \
 208         }                                                               \
 209         __total;                                                        \
 210 })
 211
 212 static inline void debug_class_ops_inc(struct lock_class *class)
 213 {
 214         int idx;
 215
 216         idx = class - lock_classes;
 217         __debug_atomic_inc(lock_class_ops[idx]);
 218 }
 219
 220 static inline unsigned long debug_class_ops_read(struct lock_class *class)
 221 {
 222         int idx, cpu;
 223         unsigned long ops = 0;
 224
 225         idx = class - lock_classes;
 226         for_each_possible_cpu(cpu)
 227                 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
 228         return ops;
 229 }
 230
 231 #else
 232 # define __debug_atomic_inc(ptr)        do { } while (0)
 233 # define debug_atomic_inc(ptr)          do { } while (0)
 234 # define debug_atomic_dec(ptr)          do { } while (0)
 235 # define debug_atomic_read(ptr)         0
 236 # define debug_class_ops_inc(ptr)       do { } while (0)
 237 #endif