Line data    Source code

       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     32768UL
     103             : 
     104             : #define MAX_LOCKDEP_CHAINS_BITS 16
     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 524288UL
     111             : #define STACK_TRACE_HASH_SIZE   16384
     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    13479995 : static inline void debug_class_ops_inc(struct lock_class *class)
     235             : {
     236    13479995 :         int idx;
     237             : 
     238    13479995 :         idx = class - lock_classes;
     239    13479995 :         __debug_atomic_inc(lock_class_ops[idx]);
     240             : }
     241             : 
     242           0 : static inline unsigned long debug_class_ops_read(struct lock_class *class)
     243             : {
     244           0 :         int idx, cpu;
     245           0 :         unsigned long ops = 0;
     246             : 
     247           0 :         idx = class - lock_classes;
     248           0 :         for_each_possible_cpu(cpu)
     249           0 :                 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
     250           0 :         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