kernel/locking/lockdep_internals.h

   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  */
  12 enum 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
  29 enum {
  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  * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
  50  * .data and .bss to fit in required 32MB limit for the kernel. With
  51  * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems.
  52  * So, reduce the static allocations for lockdeps related structures so that
  53  * everything fits in current required size limit.
  54  */
  55 #ifdef CONFIG_LOCKDEP_SMALL
  56 /*
  57  * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
  58  * we track.
  59  *
  60  * We use the per-lock dependency maps in two ways: we grow it by adding
  61  * every to-be-taken lock to all currently held lock's own dependency
  62  * table (if it's not there yet), and we check it for lock order
  63  * conflicts and deadlocks.
  64  */
  65 #define MAX_LOCKDEP_ENTRIES     16384UL
  66 #define MAX_LOCKDEP_CHAINS_BITS 15
  67 #define MAX_STACK_TRACE_ENTRIES 262144UL
  68 #else
  69 #define MAX_LOCKDEP_ENTRIES     32768UL
  70
  71 #define MAX_LOCKDEP_CHAINS_BITS 16
  72
  73 /*
  74  * Stack-trace: tightly packed array of stack backtrace
  75  * addresses. Protected by the hash_lock.
  76  */
  77 #define MAX_STACK_TRACE_ENTRIES 524288UL
  78 #endif
  79
  80 #define MAX_LOCKDEP_CHAINS      (1UL << MAX_LOCKDEP_CHAINS_BITS)
  81
  82 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
  83
  84 extern struct list_head all_lock_classes;
  85 extern struct lock_chain lock_chains[];
  86
  87 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
  88
  89 extern void get_usage_chars(struct lock_class *class,
  90                             char usage[LOCK_USAGE_CHARS]);
  91
  92 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
  93
  94 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
  95
  96 extern unsigned long nr_lock_classes;
  97 extern unsigned long nr_list_entries;
  98 extern unsigned long nr_lock_chains;
  99 extern int nr_chain_hlocks;
 100 extern unsigned long nr_stack_trace_entries;
 101
 102 extern unsigned int nr_hardirq_chains;
 103 extern unsigned int nr_softirq_chains;
 104 extern unsigned int nr_process_chains;
 105 extern unsigned int max_lockdep_depth;
 106 extern unsigned int max_recursion_depth;
 107
 108 extern unsigned int max_bfs_queue_depth;
 109
 110 #ifdef CONFIG_PROVE_LOCKING
 111 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
 112 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
 113 #else
 114 static inline unsigned long
 115 lockdep_count_forward_deps(struct lock_class *class)
 116 {
 117         return 0;
 118 }
 119 static inline unsigned long
 120 lockdep_count_backward_deps(struct lock_class *class)
 121 {
 122         return 0;
 123 }
 124 #endif
 125
 126 #ifdef CONFIG_DEBUG_LOCKDEP
 127
 128 #include <asm/local.h>
 129 /*
 130  * Various lockdep statistics.
 131  * We want them per cpu as they are often accessed in fast path
 132  * and we want to avoid too much cache bouncing.
 133  */
 134 struct lockdep_stats {
 135         int     chain_lookup_hits;
 136         int     chain_lookup_misses;
 137         int     hardirqs_on_events;
 138         int     hardirqs_off_events;
 139         int     redundant_hardirqs_on;
 140         int     redundant_hardirqs_off;
 141         int     softirqs_on_events;
 142         int     softirqs_off_events;
 143         int     redundant_softirqs_on;
 144         int     redundant_softirqs_off;
 145         int     nr_unused_locks;
 146         int     nr_cyclic_checks;
 147         int     nr_cyclic_check_recursions;
 148         int     nr_find_usage_forwards_checks;
 149         int     nr_find_usage_forwards_recursions;
 150         int     nr_find_usage_backwards_checks;
 151         int     nr_find_usage_backwards_recursions;
 152 };
 153
 154 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
 155
 156 #define __debug_atomic_inc(ptr)                                 \
 157         this_cpu_inc(lockdep_stats.ptr);
 158
 159 #define debug_atomic_inc(ptr)                   {               \
 160         WARN_ON_ONCE(!irqs_disabled());                         \
 161         __this_cpu_inc(lockdep_stats.ptr);                      \
 162 }
 163
 164 #define debug_atomic_dec(ptr)                   {               \
 165         WARN_ON_ONCE(!irqs_disabled());                         \
 166         __this_cpu_dec(lockdep_stats.ptr);                      \
 167 }
 168
 169 #define debug_atomic_read(ptr)          ({                              \
 170         struct lockdep_stats *__cpu_lockdep_stats;                      \
 171         unsigned long long __total = 0;                                 \
 172         int __cpu;                                                      \
 173         for_each_possible_cpu(__cpu) {                                  \
 174                 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);   \
 175                 __total += __cpu_lockdep_stats->ptr;                    \
 176         }                                                               \
 177         __total;                                                        \
 178 })
 179 #else
 180 # define __debug_atomic_inc(ptr)        do { } while (0)
 181 # define debug_atomic_inc(ptr)          do { } while (0)
 182 # define debug_atomic_dec(ptr)          do { } while (0)
 183 # define debug_atomic_read(ptr)         0
 184 #endif