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 /*
  26  * Usage-state bitmasks:
  27  */
  28 #define __LOCKF(__STATE)        LOCKF_##__STATE = (1 << LOCK_##__STATE),
  29
  30 enum {
  31 #define LOCKDEP_STATE(__STATE)                                          \
  32         __LOCKF(USED_IN_##__STATE)                                      \
  33         __LOCKF(USED_IN_##__STATE##_READ)                               \
  34         __LOCKF(ENABLED_##__STATE)                                      \
  35         __LOCKF(ENABLED_##__STATE##_READ)
  36 #include "lockdep_states.h"
  37 #undef LOCKDEP_STATE
  38         __LOCKF(USED)
  39 };
  40
  41 #define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
  42 #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
  43
  44 #define LOCKF_ENABLED_IRQ_READ \
  45                 (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
  46 #define LOCKF_USED_IN_IRQ_READ \
  47                 (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
  48
  49 /*
  50  * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
  51  * .data and .bss to fit in required 32MB limit for the kernel. With
  52  * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
  53  * So, reduce the static allocations for lockdeps related structures so that
  54  * everything fits in current required size limit.
  55  */
  56 #ifdef CONFIG_LOCKDEP_SMALL
  57 /*
  58  * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
  59  * we track.
  60  *
  61  * We use the per-lock dependency maps in two ways: we grow it by adding
  62  * every to-be-taken lock to all currently held lock's own dependency
  63  * table (if it's not there yet), and we check it for lock order
  64  * conflicts and deadlocks.
  65  */
  66 #define MAX_LOCKDEP_ENTRIES     16384UL
  67 #define MAX_LOCKDEP_CHAINS_BITS 15
  68 #define MAX_STACK_TRACE_ENTRIES 262144UL
  69 #else
  70 #define MAX_LOCKDEP_ENTRIES     32768UL
  71
  72 #define MAX_LOCKDEP_CHAINS_BITS 16
  73
  74 /*
  75  * Stack-trace: tightly packed array of stack backtrace
  76  * addresses. Protected by the hash_lock.
  77  */
  78 #define MAX_STACK_TRACE_ENTRIES 524288UL
  79 #endif
  80
  81 #define MAX_LOCKDEP_CHAINS      (1UL << MAX_LOCKDEP_CHAINS_BITS)
  82
  83 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
  84
  85 extern struct list_head all_lock_classes;
  86 extern struct lock_chain lock_chains[];
  87
  88 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
  89
  90 extern void get_usage_chars(struct lock_class *class,
  91                             char usage[LOCK_USAGE_CHARS]);
  92
  93 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
  94
  95 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
  96
  97 extern unsigned long nr_lock_classes;
  98 extern unsigned long nr_list_entries;
  99 extern unsigned long nr_lock_chains;
 100 extern int nr_chain_hlocks;
 101 extern unsigned long nr_stack_trace_entries;
 102
 103 extern unsigned int nr_hardirq_chains;
 104 extern unsigned int nr_softirq_chains;
 105 extern unsigned int nr_process_chains;
 106 extern unsigned int max_lockdep_depth;
 107 extern unsigned int max_recursion_depth;
 108
 109 extern unsigned int max_bfs_queue_depth;
 110
 111 #ifdef CONFIG_PROVE_LOCKING
 112 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
 113 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
 114 #else
 115 static inline unsigned long
 116 lockdep_count_forward_deps(struct lock_class *class)
 117 {
 118         return 0;
 119 }
 120 static inline unsigned long
 121 lockdep_count_backward_deps(struct lock_class *class)
 122 {
 123         return 0;
 124 }
 125 #endif
 126
 127 #ifdef CONFIG_DEBUG_LOCKDEP
 128
 129 #include <asm/local.h>
 130 /*
 131  * Various lockdep statistics.
 132  * We want them per cpu as they are often accessed in fast path
 133  * and we want to avoid too much cache bouncing.
 134  */
 135 struct lockdep_stats {
 136         int     chain_lookup_hits;
 137         int     chain_lookup_misses;
 138         int     hardirqs_on_events;
 139         int     hardirqs_off_events;
 140         int     redundant_hardirqs_on;
 141         int     redundant_hardirqs_off;
 142         int     softirqs_on_events;
 143         int     softirqs_off_events;
 144         int     redundant_softirqs_on;
 145         int     redundant_softirqs_off;
 146         int     nr_unused_locks;
 147         int     nr_redundant_checks;
 148         int     nr_redundant;
 149         int     nr_cyclic_checks;
 150         int     nr_cyclic_check_recursions;
 151         int     nr_find_usage_forwards_checks;
 152         int     nr_find_usage_forwards_recursions;
 153         int     nr_find_usage_backwards_checks;
 154         int     nr_find_usage_backwards_recursions;
 155
 156         /*
 157          * Per lock class locking operation stat counts
 158          */
 159         unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
 160 };
 161
 162 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
 163 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 164
 165 #define __debug_atomic_inc(ptr)                                 \
 166         this_cpu_inc(lockdep_stats.ptr);
 167
 168 #define debug_atomic_inc(ptr)                   {               \
 169         WARN_ON_ONCE(!irqs_disabled());                         \
 170         __this_cpu_inc(lockdep_stats.ptr);                      \
 171 }
 172
 173 #define debug_atomic_dec(ptr)                   {               \
 174         WARN_ON_ONCE(!irqs_disabled());                         \
 175         __this_cpu_dec(lockdep_stats.ptr);                      \
 176 }
 177
 178 #define debug_atomic_read(ptr)          ({                              \
 179         struct lockdep_stats *__cpu_lockdep_stats;                      \
 180         unsigned long long __total = 0;                                 \
 181         int __cpu;                                                      \
 182         for_each_possible_cpu(__cpu) {                                  \
 183                 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);   \
 184                 __total += __cpu_lockdep_stats->ptr;                    \
 185         }                                                               \
 186         __total;                                                        \
 187 })
 188
 189 static inline void debug_class_ops_inc(struct lock_class *class)
 190 {
 191         int idx;
 192
 193         idx = class - lock_classes;
 194         __debug_atomic_inc(lock_class_ops[idx]);
 195 }
 196
 197 static inline unsigned long debug_class_ops_read(struct lock_class *class)
 198 {
 199         int idx, cpu;
 200         unsigned long ops = 0;
 201
 202         idx = class - lock_classes;
 203         for_each_possible_cpu(cpu)
 204                 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
 205         return ops;
 206 }
 207
 208 #else
 209 # define __debug_atomic_inc(ptr)        do { } while (0)
 210 # define debug_atomic_inc(ptr)          do { } while (0)
 211 # define debug_atomic_dec(ptr)          do { } while (0)
 212 # define debug_atomic_read(ptr)         0
 213 # define debug_class_ops_inc(ptr)       do { } while (0)
 214 #endif