| /* |
| * Runtime locking correctness validator |
| * |
| * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
| * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra |
| * |
| * see Documentation/locking/lockdep-design.txt for more details. |
| */ |
| #ifndef __LINUX_LOCKDEP_H |
| #define __LINUX_LOCKDEP_H |
| |
| struct task_struct; |
| struct lockdep_map; |
| |
| /* for sysctl */ |
| extern int prove_locking; |
| extern int lock_stat; |
| |
| #ifdef CONFIG_LOCKDEP |
| |
| #include <linux/linkage.h> |
| #include <linux/list.h> |
| #include <linux/debug_locks.h> |
| #include <linux/stacktrace.h> |
| |
| /* |
| * We'd rather not expose kernel/lockdep_states.h this wide, but we do need |
| * the total number of states... :-( |
| */ |
| #define XXX_LOCK_USAGE_STATES (1+3*4) |
| |
| #define MAX_LOCKDEP_SUBCLASSES 8UL |
| |
| /* |
| * NR_LOCKDEP_CACHING_CLASSES ... Number of classes |
| * cached in the instance of lockdep_map |
| * |
| * Currently main class (subclass == 0) and signle depth subclass |
| * are cached in lockdep_map. This optimization is mainly targeting |
| * on rq->lock. double_rq_lock() acquires this highly competitive with |
| * single depth. |
| */ |
| #define NR_LOCKDEP_CACHING_CLASSES 2 |
| |
| /* |
| * Lock-classes are keyed via unique addresses, by embedding the |
| * lockclass-key into the kernel (or module) .data section. (For |
| * static locks we use the lock address itself as the key.) |
| */ |
| struct lockdep_subclass_key { |
| char __one_byte; |
| } __attribute__ ((__packed__)); |
| |
| struct lock_class_key { |
| struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES]; |
| }; |
| |
| extern struct lock_class_key __lockdep_no_validate__; |
| |
| #define LOCKSTAT_POINTS 4 |
| |
| /* |
| * The lock-class itself: |
| */ |
| struct lock_class { |
| /* |
| * class-hash: |
| */ |
| struct hlist_node hash_entry; |
| |
| /* |
| * global list of all lock-classes: |
| */ |
| struct list_head lock_entry; |
| |
| struct lockdep_subclass_key *key; |
| unsigned int subclass; |
| unsigned int dep_gen_id; |
| |
| /* |
| * IRQ/softirq usage tracking bits: |
| */ |
| unsigned long usage_mask; |
| struct stack_trace usage_traces[XXX_LOCK_USAGE_STATES]; |
| |
| /* |
| * These fields represent a directed graph of lock dependencies, |
| * to every node we attach a list of "forward" and a list of |
| * "backward" graph nodes. |
| */ |
| struct list_head locks_after, locks_before; |
| |
| /* |
| * Generation counter, when doing certain classes of graph walking, |
| * to ensure that we check one node only once: |
| */ |
| unsigned int version; |
| |
| /* |
| * Statistics counter: |
| */ |
| unsigned long ops; |
| |
| const char *name; |
| int name_version; |
| |
| #ifdef CONFIG_LOCK_STAT |
| unsigned long contention_point[LOCKSTAT_POINTS]; |
| unsigned long contending_point[LOCKSTAT_POINTS]; |
| #endif |
| }; |
| |
| #ifdef CONFIG_LOCK_STAT |
| struct lock_time { |
| s64 min; |
| s64 max; |
| s64 total; |
| unsigned long nr; |
| }; |
| |
| enum bounce_type { |
| bounce_acquired_write, |
| bounce_acquired_read, |
| bounce_contended_write, |
| bounce_contended_read, |
| nr_bounce_types, |
| |
| bounce_acquired = bounce_acquired_write, |
| bounce_contended = bounce_contended_write, |
| }; |
| |
| struct lock_class_stats { |
| unsigned long contention_point[LOCKSTAT_POINTS]; |
| unsigned long contending_point[LOCKSTAT_POINTS]; |
| struct lock_time read_waittime; |
| struct lock_time write_waittime; |
| struct lock_time read_holdtime; |
| struct lock_time write_holdtime; |
| unsigned long bounces[nr_bounce_types]; |
| }; |
| |
| struct lock_class_stats lock_stats(struct lock_class *class); |
| void clear_lock_stats(struct lock_class *class); |
| #endif |
| |
| /* |
| * Map the lock object (the lock instance) to the lock-class object. |
| * This is embedded into specific lock instances: |
| */ |
| struct lockdep_map { |
| struct lock_class_key *key; |
| struct lock_class *class_cache[NR_LOCKDEP_CACHING_CLASSES]; |
| const char *name; |
| #ifdef CONFIG_LOCK_STAT |
| int cpu; |
| unsigned long ip; |
| #endif |
| }; |
| |
| static inline void lockdep_copy_map(struct lockdep_map *to, |
| struct lockdep_map *from) |
| { |
| int i; |
| |
| *to = *from; |
| /* |
| * Since the class cache can be modified concurrently we could observe |
| * half pointers (64bit arch using 32bit copy insns). Therefore clear |
| * the caches and take the performance hit. |
| * |
| * XXX it doesn't work well with lockdep_set_class_and_subclass(), since |
| * that relies on cache abuse. |
| */ |
| for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++) |
| to->class_cache[i] = NULL; |
| } |
| |
| /* |
| * Every lock has a list of other locks that were taken after it. |
| * We only grow the list, never remove from it: |
| */ |
| struct lock_list { |
| struct list_head entry; |
| struct lock_class *class; |
| struct stack_trace trace; |
| int distance; |
| |
| /* |
| * The parent field is used to implement breadth-first search, and the |
| * bit 0 is reused to indicate if the lock has been accessed in BFS. |
| */ |
| struct lock_list *parent; |
| }; |
| |
| /* |
| * We record lock dependency chains, so that we can cache them: |
| */ |
| struct lock_chain { |
| /* see BUILD_BUG_ON()s in lookup_chain_cache() */ |
| unsigned int irq_context : 2, |
| depth : 6, |
| base : 24; |
| /* 4 byte hole */ |
| struct hlist_node entry; |
| u64 chain_key; |
| }; |
| |
| #define MAX_LOCKDEP_KEYS_BITS 13 |
| /* |
| * Subtract one because we offset hlock->class_idx by 1 in order |
| * to make 0 mean no class. This avoids overflowing the class_idx |
| * bitfield and hitting the BUG in hlock_class(). |
| */ |
| #define MAX_LOCKDEP_KEYS ((1UL << MAX_LOCKDEP_KEYS_BITS) - 1) |
| |
| struct held_lock { |
| /* |
| * One-way hash of the dependency chain up to this point. We |
| * hash the hashes step by step as the dependency chain grows. |
| * |
| * We use it for dependency-caching and we skip detection |
| * passes and dependency-updates if there is a cache-hit, so |
| * it is absolutely critical for 100% coverage of the validator |
| * to have a unique key value for every unique dependency path |
| * that can occur in the system, to make a unique hash value |
| * as likely as possible - hence the 64-bit width. |
| * |
| * The task struct holds the current hash value (initialized |
| * with zero), here we store the previous hash value: |
| */ |
| u64 prev_chain_key; |
| unsigned long acquire_ip; |
| struct lockdep_map *instance; |
| struct lockdep_map *nest_lock; |
| #ifdef CONFIG_LOCK_STAT |
| u64 waittime_stamp; |
| u64 holdtime_stamp; |
| #endif |
| unsigned int class_idx:MAX_LOCKDEP_KEYS_BITS; |
| /* |
| * The lock-stack is unified in that the lock chains of interrupt |
| * contexts nest ontop of process context chains, but we 'separate' |
| * the hashes by starting with 0 if we cross into an interrupt |
| * context, and we also keep do not add cross-context lock |
| * dependencies - the lock usage graph walking covers that area |
| * anyway, and we'd just unnecessarily increase the number of |
| * dependencies otherwise. [Note: hardirq and softirq contexts |
| * are separated from each other too.] |
| * |
| * The following field is used to detect when we cross into an |
| * interrupt context: |
| */ |
| unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */ |
| unsigned int trylock:1; /* 16 bits */ |
| |
| unsigned int read:2; /* see lock_acquire() comment */ |
| unsigned int check:1; /* see lock_acquire() comment */ |
| unsigned int hardirqs_off:1; |
| unsigned int references:12; /* 32 bits */ |
| unsigned int pin_count; |
| }; |
| |
| /* |
| * Initialization, self-test and debugging-output methods: |
| */ |
| extern void lockdep_info(void); |
| extern void lockdep_reset(void); |
| extern void lockdep_reset_lock(struct lockdep_map *lock); |
| extern void lockdep_free_key_range(void *start, unsigned long size); |
| extern asmlinkage void lockdep_sys_exit(void); |
| |
| extern void lockdep_off(void); |
| extern void lockdep_on(void); |
| |
| /* |
| * These methods are used by specific locking variants (spinlocks, |
| * rwlocks, mutexes and rwsems) to pass init/acquire/release events |
| * to lockdep: |
| */ |
| |
| extern void lockdep_init_map(struct lockdep_map *lock, const char *name, |
| struct lock_class_key *key, int subclass); |
| |
| /* |
| * To initialize a lockdep_map statically use this macro. |
| * Note that _name must not be NULL. |
| */ |
| #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \ |
| { .name = (_name), .key = (void *)(_key), } |
| |
| /* |
| * Reinitialize a lock key - for cases where there is special locking or |
| * special initialization of locks so that the validator gets the scope |
| * of dependencies wrong: they are either too broad (they need a class-split) |
| * or they are too narrow (they suffer from a false class-split): |
| */ |
| #define lockdep_set_class(lock, key) \ |
| lockdep_init_map(&(lock)->dep_map, #key, key, 0) |
| #define lockdep_set_class_and_name(lock, key, name) \ |
| lockdep_init_map(&(lock)->dep_map, name, key, 0) |
| #define lockdep_set_class_and_subclass(lock, key, sub) \ |
| lockdep_init_map(&(lock)->dep_map, #key, key, sub) |
| #define lockdep_set_subclass(lock, sub) \ |
| lockdep_init_map(&(lock)->dep_map, #lock, \ |
| (lock)->dep_map.key, sub) |
| |
| #define lockdep_set_novalidate_class(lock) \ |
| lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock) |
| /* |
| * Compare locking classes |
| */ |
| #define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key) |
| |
| static inline int lockdep_match_key(struct lockdep_map *lock, |
| struct lock_class_key *key) |
| { |
| return lock->key == key; |
| } |
| |
| /* |
| * Acquire a lock. |
| * |
| * Values for "read": |
| * |
| * 0: exclusive (write) acquire |
| * 1: read-acquire (no recursion allowed) |
| * 2: read-acquire with same-instance recursion allowed |
| * |
| * Values for check: |
| * |
| * 0: simple checks (freeing, held-at-exit-time, etc.) |
| * 1: full validation |
| */ |
| extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass, |
| int trylock, int read, int check, |
| struct lockdep_map *nest_lock, unsigned long ip); |
| |
| extern void lock_release(struct lockdep_map *lock, int nested, |
| unsigned long ip); |
| |
| #define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map) |
| |
| extern int lock_is_held(struct lockdep_map *lock); |
| |
| extern void lock_set_class(struct lockdep_map *lock, const char *name, |
| struct lock_class_key *key, unsigned int subclass, |
| unsigned long ip); |
| |
| static inline void lock_set_subclass(struct lockdep_map *lock, |
| unsigned int subclass, unsigned long ip) |
| { |
| lock_set_class(lock, lock->name, lock->key, subclass, ip); |
| } |
| |
| extern void lockdep_set_current_reclaim_state(gfp_t gfp_mask); |
| extern void lockdep_clear_current_reclaim_state(void); |
| extern void lockdep_trace_alloc(gfp_t mask); |
| |
| extern void lock_pin_lock(struct lockdep_map *lock); |
| extern void lock_unpin_lock(struct lockdep_map *lock); |
| |
| # define INIT_LOCKDEP .lockdep_recursion = 0, .lockdep_reclaim_gfp = 0, |
| |
| #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) |
| |
| #define lockdep_assert_held(l) do { \ |
| WARN_ON(debug_locks && !lockdep_is_held(l)); \ |
| } while (0) |
| |
| #define lockdep_assert_held_once(l) do { \ |
| WARN_ON_ONCE(debug_locks && !lockdep_is_held(l)); \ |
| } while (0) |
| |
| #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion) |
| |
| #define lockdep_pin_lock(l) lock_pin_lock(&(l)->dep_map) |
| #define lockdep_unpin_lock(l) lock_unpin_lock(&(l)->dep_map) |
| |
| #else /* !CONFIG_LOCKDEP */ |
| |
| static inline void lockdep_off(void) |
| { |
| } |
| |
| static inline void lockdep_on(void) |
| { |
| } |
| |
| # define lock_acquire(l, s, t, r, c, n, i) do { } while (0) |
| # define lock_release(l, n, i) do { } while (0) |
| # define lock_set_class(l, n, k, s, i) do { } while (0) |
| # define lock_set_subclass(l, s, i) do { } while (0) |
| # define lockdep_set_current_reclaim_state(g) do { } while (0) |
| # define lockdep_clear_current_reclaim_state() do { } while (0) |
| # define lockdep_trace_alloc(g) do { } while (0) |
| # define lockdep_info() do { } while (0) |
| # define lockdep_init_map(lock, name, key, sub) \ |
| do { (void)(name); (void)(key); } while (0) |
| # define lockdep_set_class(lock, key) do { (void)(key); } while (0) |
| # define lockdep_set_class_and_name(lock, key, name) \ |
| do { (void)(key); (void)(name); } while (0) |
| #define lockdep_set_class_and_subclass(lock, key, sub) \ |
| do { (void)(key); } while (0) |
| #define lockdep_set_subclass(lock, sub) do { } while (0) |
| |
| #define lockdep_set_novalidate_class(lock) do { } while (0) |
| |
| /* |
| * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP |
| * case since the result is not well defined and the caller should rather |
| * #ifdef the call himself. |
| */ |
| |
| # define INIT_LOCKDEP |
| # define lockdep_reset() do { debug_locks = 1; } while (0) |
| # define lockdep_free_key_range(start, size) do { } while (0) |
| # define lockdep_sys_exit() do { } while (0) |
| /* |
| * The class key takes no space if lockdep is disabled: |
| */ |
| struct lock_class_key { }; |
| |
| #define lockdep_depth(tsk) (0) |
| |
| #define lockdep_assert_held(l) do { (void)(l); } while (0) |
| #define lockdep_assert_held_once(l) do { (void)(l); } while (0) |
| |
| #define lockdep_recursing(tsk) (0) |
| |
| #define lockdep_pin_lock(l) do { (void)(l); } while (0) |
| #define lockdep_unpin_lock(l) do { (void)(l); } while (0) |
| |
| #endif /* !LOCKDEP */ |
| |
| #ifdef CONFIG_LOCK_STAT |
| |
| extern void lock_contended(struct lockdep_map *lock, unsigned long ip); |
| extern void lock_acquired(struct lockdep_map *lock, unsigned long ip); |
| |
| #define LOCK_CONTENDED(_lock, try, lock) \ |
| do { \ |
| if (!try(_lock)) { \ |
| lock_contended(&(_lock)->dep_map, _RET_IP_); \ |
| lock(_lock); \ |
| } \ |
| lock_acquired(&(_lock)->dep_map, _RET_IP_); \ |
| } while (0) |
| |
| #else /* CONFIG_LOCK_STAT */ |
| |
| #define lock_contended(lockdep_map, ip) do {} while (0) |
| #define lock_acquired(lockdep_map, ip) do {} while (0) |
| |
| #define LOCK_CONTENDED(_lock, try, lock) \ |
| lock(_lock) |
| |
| #endif /* CONFIG_LOCK_STAT */ |
| |
| #ifdef CONFIG_LOCKDEP |
| |
| /* |
| * On lockdep we dont want the hand-coded irq-enable of |
| * _raw_*_lock_flags() code, because lockdep assumes |
| * that interrupts are not re-enabled during lock-acquire: |
| */ |
| #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \ |
| LOCK_CONTENDED((_lock), (try), (lock)) |
| |
| #else /* CONFIG_LOCKDEP */ |
| |
| #define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \ |
| lockfl((_lock), (flags)) |
| |
| #endif /* CONFIG_LOCKDEP */ |
| |
| #ifdef CONFIG_TRACE_IRQFLAGS |
| extern void print_irqtrace_events(struct task_struct *curr); |
| #else |
| static inline void print_irqtrace_events(struct task_struct *curr) |
| { |
| } |
| #endif |
| |
| /* |
| * For trivial one-depth nesting of a lock-class, the following |
| * global define can be used. (Subsystems with multiple levels |
| * of nesting should define their own lock-nesting subclasses.) |
| */ |
| #define SINGLE_DEPTH_NESTING 1 |
| |
| /* |
| * Map the dependency ops to NOP or to real lockdep ops, depending |
| * on the per lock-class debug mode: |
| */ |
| |
| #define lock_acquire_exclusive(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, n, i) |
| #define lock_acquire_shared(l, s, t, n, i) lock_acquire(l, s, t, 1, 1, n, i) |
| #define lock_acquire_shared_recursive(l, s, t, n, i) lock_acquire(l, s, t, 2, 1, n, i) |
| |
| #define spin_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) |
| #define spin_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i) |
| #define spin_release(l, n, i) lock_release(l, n, i) |
| |
| #define rwlock_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) |
| #define rwlock_acquire_read(l, s, t, i) lock_acquire_shared_recursive(l, s, t, NULL, i) |
| #define rwlock_release(l, n, i) lock_release(l, n, i) |
| |
| #define seqcount_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) |
| #define seqcount_acquire_read(l, s, t, i) lock_acquire_shared_recursive(l, s, t, NULL, i) |
| #define seqcount_release(l, n, i) lock_release(l, n, i) |
| |
| #define mutex_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) |
| #define mutex_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i) |
| #define mutex_release(l, n, i) lock_release(l, n, i) |
| |
| #define rwsem_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i) |
| #define rwsem_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i) |
| #define rwsem_acquire_read(l, s, t, i) lock_acquire_shared(l, s, t, NULL, i) |
| #define rwsem_release(l, n, i) lock_release(l, n, i) |
| |
| #define lock_map_acquire(l) lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_) |
| #define lock_map_acquire_read(l) lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_) |
| #define lock_map_acquire_tryread(l) lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_) |
| #define lock_map_release(l) lock_release(l, 1, _THIS_IP_) |
| |
| #ifdef CONFIG_PROVE_LOCKING |
| # define might_lock(lock) \ |
| do { \ |
| typecheck(struct lockdep_map *, &(lock)->dep_map); \ |
| lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_); \ |
| lock_release(&(lock)->dep_map, 0, _THIS_IP_); \ |
| } while (0) |
| # define might_lock_read(lock) \ |
| do { \ |
| typecheck(struct lockdep_map *, &(lock)->dep_map); \ |
| lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_); \ |
| lock_release(&(lock)->dep_map, 0, _THIS_IP_); \ |
| } while (0) |
| #else |
| # define might_lock(lock) do { } while (0) |
| # define might_lock_read(lock) do { } while (0) |
| #endif |
| |
| #ifdef CONFIG_LOCKDEP |
| void lockdep_rcu_suspicious(const char *file, const int line, const char *s); |
| #else |
| static inline void |
| lockdep_rcu_suspicious(const char *file, const int line, const char *s) |
| { |
| } |
| #endif |
| |
| #endif /* __LINUX_LOCKDEP_H */ |