LXR linux/kernel/lockdep

   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 */
  12enum 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
  29enum {
  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
  70extern struct list_head all_lock_classes;
  71extern struct lock_chain lock_chains[];
  72
  73#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
  74
  75extern void get_usage_chars(struct lock_class *class,
  76                            char usage[LOCK_USAGE_CHARS]);
  77
  78extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
  79
  80struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
  81
  82extern unsigned long nr_lock_classes;
  83extern unsigned long nr_list_entries;
  84extern unsigned long nr_lock_chains;
  85extern int nr_chain_hlocks;
  86extern unsigned long nr_stack_trace_entries;
  87
  88extern unsigned int nr_hardirq_chains;
  89extern unsigned int nr_softirq_chains;
  90extern unsigned int nr_process_chains;
  91extern unsigned int max_lockdep_depth;
  92extern unsigned int max_recursion_depth;
  93
  94extern unsigned int max_bfs_queue_depth;
  95
  96#ifdef CONFIG_PROVE_LOCKING
  97extern unsigned long lockdep_count_forward_deps(struct lock_class *);
  98extern unsigned long lockdep_count_backward_deps(struct lock_class *);
  99#else
 100static inline unsigned long
 101lockdep_count_forward_deps(struct lock_class *class)
 102{
 103        return 0;
 104}
 105static inline unsigned long
 106lockdep_count_backward_deps(struct lock_class *class)
 107{
 108        return 0;
 109}
 110#endif
 111
 112#ifdef CONFIG_DEBUG_LOCKDEP
 113
 114#include <asm/local.h>
 115/*
 116 * Various lockdep statistics.
 117 * We want them per cpu as they are often accessed in fast path
 118 * and we want to avoid too much cache bouncing.
 119 */
 120struct lockdep_stats {
 121        int     chain_lookup_hits;
 122        int     chain_lookup_misses;
 123        int     hardirqs_on_events;
 124        int     hardirqs_off_events;
 125        int     redundant_hardirqs_on;
 126        int     redundant_hardirqs_off;
 127        int     softirqs_on_events;
 128        int     softirqs_off_events;
 129        int     redundant_softirqs_on;
 130        int     redundant_softirqs_off;
 131        int     nr_unused_locks;
 132        int     nr_cyclic_checks;
 133        int     nr_cyclic_check_recursions;
 134        int     nr_find_usage_forwards_checks;
 135        int     nr_find_usage_forwards_recursions;
 136        int     nr_find_usage_backwards_checks;
 137        int     nr_find_usage_backwards_recursions;
 138};
 139
 140DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
 141
 142#define __debug_atomic_inc(ptr)                                 \
 143        this_cpu_inc(lockdep_stats.ptr);
 144
 145#define debug_atomic_inc(ptr)                   {               \
 146        WARN_ON_ONCE(!irqs_disabled());                         \
 147        __this_cpu_inc(lockdep_stats.ptr);                      \
 148}
 149
 150#define debug_atomic_dec(ptr)                   {               \
 151        WARN_ON_ONCE(!irqs_disabled());                         \
 152        __this_cpu_dec(lockdep_stats.ptr);                      \
 153}
 154
 155#define debug_atomic_read(ptr)          ({                              \
 156        struct lockdep_stats *__cpu_lockdep_stats;                      \
 157        unsigned long long __total = 0;                                 \
 158        int __cpu;                                                      \
 159        for_each_possible_cpu(__cpu) {                                  \
 160                __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);   \
 161                __total += __cpu_lockdep_stats->ptr;                    \
 162        }                                                               \
 163        __total;                                                        \
 164})
 165#else
 166# define __debug_atomic_inc(ptr)        do { } while (0)
 167# define debug_atomic_inc(ptr)          do { } while (0)
 168# define debug_atomic_dec(ptr)          do { } while (0)
 169# define debug_atomic_read(ptr)         0
 170#endif
 171