0,0 → 1,537 |
/* |
* Runtime locking correctness validator |
* |
* Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> |
* |
* see Documentation/lockdep-design.txt for more details. |
*/ |
#ifndef __LINUX_LOCKDEP_H |
#define __LINUX_LOCKDEP_H |
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struct task_struct; |
struct lockdep_map; |
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#ifdef CONFIG_LOCKDEP |
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#include <linux/linkage.h> |
#include <linux/list.h> |
#include <linux/debug_locks.h> |
#include <linux/stacktrace.h> |
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/* |
* 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) |
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#define MAX_LOCKDEP_SUBCLASSES 8UL |
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/* |
* 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__)); |
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struct lock_class_key { |
struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES]; |
}; |
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#define LOCKSTAT_POINTS 4 |
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/* |
* The lock-class itself: |
*/ |
struct lock_class { |
/* |
* class-hash: |
*/ |
struct list_head hash_entry; |
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/* |
* global list of all lock-classes: |
*/ |
struct list_head lock_entry; |
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struct lockdep_subclass_key *key; |
unsigned int subclass; |
unsigned int dep_gen_id; |
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/* |
* IRQ/softirq usage tracking bits: |
*/ |
unsigned long usage_mask; |
struct stack_trace usage_traces[XXX_LOCK_USAGE_STATES]; |
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/* |
* 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; |
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/* |
* Generation counter, when doing certain classes of graph walking, |
* to ensure that we check one node only once: |
*/ |
unsigned int version; |
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/* |
* Statistics counter: |
*/ |
unsigned long ops; |
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const char *name; |
int name_version; |
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#ifdef CONFIG_LOCK_STAT |
unsigned long contention_point[LOCKSTAT_POINTS]; |
unsigned long contending_point[LOCKSTAT_POINTS]; |
#endif |
}; |
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#ifdef CONFIG_LOCK_STAT |
struct lock_time { |
s64 min; |
s64 max; |
s64 total; |
unsigned long nr; |
}; |
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enum bounce_type { |
bounce_acquired_write, |
bounce_acquired_read, |
bounce_contended_write, |
bounce_contended_read, |
nr_bounce_types, |
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bounce_acquired = bounce_acquired_write, |
bounce_contended = bounce_contended_write, |
}; |
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struct lock_class_stats { |
unsigned long contention_point[4]; |
unsigned long contending_point[4]; |
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]; |
}; |
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struct lock_class_stats lock_stats(struct lock_class *class); |
void clear_lock_stats(struct lock_class *class); |
#endif |
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/* |
* 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; |
const char *name; |
#ifdef CONFIG_LOCK_STAT |
int cpu; |
unsigned long ip; |
#endif |
}; |
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/* |
* 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; |
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/* |
* 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; |
}; |
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/* |
* We record lock dependency chains, so that we can cache them: |
*/ |
struct lock_chain { |
u8 irq_context; |
u8 depth; |
u16 base; |
struct list_head entry; |
u64 chain_key; |
}; |
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#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) |
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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 */ |
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unsigned int read:2; /* see lock_acquire() comment */ |
unsigned int check:2; /* see lock_acquire() comment */ |
unsigned int hardirqs_off:1; |
unsigned int references:11; /* 32 bits */ |
}; |
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/* |
* Initialization, self-test and debugging-output methods: |
*/ |
extern void lockdep_init(void); |
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 void lockdep_sys_exit(void); |
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extern void lockdep_off(void); |
extern void lockdep_on(void); |
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/* |
* These methods are used by specific locking variants (spinlocks, |
* rwlocks, mutexes and rwsems) to pass init/acquire/release events |
* to lockdep: |
*/ |
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extern void lockdep_init_map(struct lockdep_map *lock, const char *name, |
struct lock_class_key *key, int subclass); |
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/* |
* 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), } |
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/* |
* 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) |
/* |
* Compare locking classes |
*/ |
#define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key) |
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static inline int lockdep_match_key(struct lockdep_map *lock, |
struct lock_class_key *key) |
{ |
return lock->key == key; |
} |
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/* |
* 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: disabled |
* 1: simple checks (freeing, held-at-exit-time, etc.) |
* 2: 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); |
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extern void lock_release(struct lockdep_map *lock, int nested, |
unsigned long ip); |
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#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map) |
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extern int lock_is_held(struct lockdep_map *lock); |
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extern void lock_set_class(struct lockdep_map *lock, const char *name, |
struct lock_class_key *key, unsigned int subclass, |
unsigned long ip); |
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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); |
} |
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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); |
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# define INIT_LOCKDEP .lockdep_recursion = 0, .lockdep_reclaim_gfp = 0, |
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#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) |
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#define lockdep_assert_held(l) WARN_ON(debug_locks && !lockdep_is_held(l)) |
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#else /* !LOCKDEP */ |
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static inline void lockdep_off(void) |
{ |
} |
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static inline void lockdep_on(void) |
{ |
} |
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# 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_init() 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) |
/* |
* 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. |
*/ |
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# 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 { }; |
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#define lockdep_depth(tsk) (0) |
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#define lockdep_assert_held(l) do { } while (0) |
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#endif /* !LOCKDEP */ |
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#ifdef CONFIG_LOCK_STAT |
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extern void lock_contended(struct lockdep_map *lock, unsigned long ip); |
extern void lock_acquired(struct lockdep_map *lock, unsigned long ip); |
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#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) |
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#else /* CONFIG_LOCK_STAT */ |
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#define lock_contended(lockdep_map, ip) do {} while (0) |
#define lock_acquired(lockdep_map, ip) do {} while (0) |
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#define LOCK_CONTENDED(_lock, try, lock) \ |
lock(_lock) |
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#endif /* CONFIG_LOCK_STAT */ |
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#ifdef CONFIG_LOCKDEP |
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/* |
* 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)) |
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#else /* CONFIG_LOCKDEP */ |
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#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \ |
lockfl((_lock), (flags)) |
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#endif /* CONFIG_LOCKDEP */ |
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#ifdef CONFIG_GENERIC_HARDIRQS |
extern void early_init_irq_lock_class(void); |
#else |
static inline void early_init_irq_lock_class(void) |
{ |
} |
#endif |
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#ifdef CONFIG_TRACE_IRQFLAGS |
extern void early_boot_irqs_off(void); |
extern void early_boot_irqs_on(void); |
extern void print_irqtrace_events(struct task_struct *curr); |
#else |
static inline void early_boot_irqs_off(void) |
{ |
} |
static inline void early_boot_irqs_on(void) |
{ |
} |
static inline void print_irqtrace_events(struct task_struct *curr) |
{ |
} |
#endif |
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/* |
* 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 |
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/* |
* Map the dependency ops to NOP or to real lockdep ops, depending |
* on the per lock-class debug mode: |
*/ |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
# ifdef CONFIG_PROVE_LOCKING |
# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) |
# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i) |
# else |
# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) |
# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, NULL, i) |
# endif |
# define spin_release(l, n, i) lock_release(l, n, i) |
#else |
# define spin_acquire(l, s, t, i) do { } while (0) |
# define spin_release(l, n, i) do { } while (0) |
#endif |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
# ifdef CONFIG_PROVE_LOCKING |
# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) |
# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, NULL, i) |
# else |
# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) |
# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, NULL, i) |
# endif |
# define rwlock_release(l, n, i) lock_release(l, n, i) |
#else |
# define rwlock_acquire(l, s, t, i) do { } while (0) |
# define rwlock_acquire_read(l, s, t, i) do { } while (0) |
# define rwlock_release(l, n, i) do { } while (0) |
#endif |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
# ifdef CONFIG_PROVE_LOCKING |
# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) |
# else |
# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) |
# endif |
# define mutex_release(l, n, i) lock_release(l, n, i) |
#else |
# define mutex_acquire(l, s, t, i) do { } while (0) |
# define mutex_release(l, n, i) do { } while (0) |
#endif |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
# ifdef CONFIG_PROVE_LOCKING |
# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) |
# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, NULL, i) |
# else |
# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) |
# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, NULL, i) |
# endif |
# define rwsem_release(l, n, i) lock_release(l, n, i) |
#else |
# define rwsem_acquire(l, s, t, i) do { } while (0) |
# define rwsem_acquire_read(l, s, t, i) do { } while (0) |
# define rwsem_release(l, n, i) do { } while (0) |
#endif |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
# ifdef CONFIG_PROVE_LOCKING |
# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_) |
# else |
# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_) |
# endif |
# define lock_map_release(l) lock_release(l, 1, _THIS_IP_) |
#else |
# define lock_map_acquire(l) do { } while (0) |
# define lock_map_release(l) do { } while (0) |
#endif |
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#ifdef CONFIG_PROVE_LOCKING |
# define might_lock(lock) \ |
do { \ |
typecheck(struct lockdep_map *, &(lock)->dep_map); \ |
lock_acquire(&(lock)->dep_map, 0, 0, 0, 2, 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, 2, 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 |
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#endif /* __LINUX_LOCKDEP_H */ |