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_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 MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
 123
 124 extern struct list_head all_lock_classes;
 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
 155 #ifdef CONFIG_PROVE_LOCKING
 156 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
 157 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
 158 #ifdef CONFIG_TRACE_IRQFLAGS
 159 u64 lockdep_stack_trace_count(void);
 160 u64 lockdep_stack_hash_count(void);
 161 #endif
 162 #else
 163 static inline unsigned long
 164 lockdep_count_forward_deps(struct lock_class *class)
 165 {
 166         return 0;
 167 }
 168 static inline unsigned long
 169 lockdep_count_backward_deps(struct lock_class *class)
 170 {
 171         return 0;
 172 }
 173 #endif
 174
 175 #ifdef CONFIG_DEBUG_LOCKDEP
 176
 177 #include <asm/local.h>
 178 /*
 179  * Various lockdep statistics.
 180  * We want them per cpu as they are often accessed in fast path
 181  * and we want to avoid too much cache bouncing.
 182  */
 183 struct lockdep_stats {
 184         unsigned long  chain_lookup_hits;
 185         unsigned int   chain_lookup_misses;
 186         unsigned long  hardirqs_on_events;
 187         unsigned long  hardirqs_off_events;
 188         unsigned long  redundant_hardirqs_on;
 189         unsigned long  redundant_hardirqs_off;
 190         unsigned long  softirqs_on_events;
 191         unsigned long  softirqs_off_events;
 192         unsigned long  redundant_softirqs_on;
 193         unsigned long  redundant_softirqs_off;
 194         int            nr_unused_locks;
 195         unsigned int   nr_redundant_checks;
 196         unsigned int   nr_redundant;
 197         unsigned int   nr_cyclic_checks;
 198         unsigned int   nr_find_usage_forwards_checks;
 199         unsigned int   nr_find_usage_backwards_checks;
 200
 201         /*
 202          * Per lock class locking operation stat counts
 203          */
 204         unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
 205 };
 206
 207 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
 208 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 209
 210 #define __debug_atomic_inc(ptr)                                 \
 211         this_cpu_inc(lockdep_stats.ptr);
 212
 213 #define debug_atomic_inc(ptr)                   {               \
 214         WARN_ON_ONCE(!irqs_disabled());                         \
 215         __this_cpu_inc(lockdep_stats.ptr);                      \
 216 }
 217
 218 #define debug_atomic_dec(ptr)                   {               \
 219         WARN_ON_ONCE(!irqs_disabled());                         \
 220         __this_cpu_dec(lockdep_stats.ptr);                      \
 221 }
 222
 223 #define debug_atomic_read(ptr)          ({                              \
 224         struct lockdep_stats *__cpu_lockdep_stats;                      \
 225         unsigned long long __total = 0;                                 \
 226         int __cpu;                                                      \
 227         for_each_possible_cpu(__cpu) {                                  \
 228                 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);   \
 229                 __total += __cpu_lockdep_stats->ptr;                    \
 230         }                                                               \
 231         __total;                                                        \
 232 })
 233
 234 static inline void debug_class_ops_inc(struct lock_class *class)
 235 {
 236         int idx;
 237
 238         idx = class - lock_classes;
 239         __debug_atomic_inc(lock_class_ops[idx]);
 240 }
 241
 242 static inline unsigned long debug_class_ops_read(struct lock_class *class)
 243 {
 244         int idx, cpu;
 245         unsigned long ops = 0;
 246
 247         idx = class - lock_classes;
 248         for_each_possible_cpu(cpu)
 249                 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
 250         return ops;
 251 }
 252
 253 #else
 254 # define __debug_atomic_inc(ptr)        do { } while (0)
 255 # define debug_atomic_inc(ptr)          do { } while (0)
 256 # define debug_atomic_dec(ptr)          do { } while (0)
 257 # define debug_atomic_read(ptr)         0
 258 # define debug_class_ops_inc(ptr)       do { } while (0)
 259 #endif