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Release 4.7 include/linux/lockdep.h

Directory: include/linux
/*
 * 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; }

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peter zijlstrapeter zijlstra49100.00%1100.00%
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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; /* * 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; }

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jan karajan kara24100.00%1100.00%
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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: 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); }

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peter zijlstrapeter zijlstra37100.00%1100.00%
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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); struct pin_cookie { unsigned int val; }; #define NIL_COOKIE (struct pin_cookie){ .val = 0U, } extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock); extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie); extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); # 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_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c)) #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c)) #else /* !CONFIG_LOCKDEP */
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_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) struct pin_cookie { }; #define NIL_COOKIE (struct pin_cookie){ } #define lockdep_pin_lock(l) ({ struct pin_cookie cookie; cookie; }) #define lockdep_repin_lock(l, c) do { (void)(l); (void)(c); } while (0) #define lockdep_unpin_lock(l, c) do { (void)(l); (void)(c); } 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) #define LOCK_CONTENDED_RETURN(_lock, try, lock) \ ({ \ int ____err = 0; \ if (!try(_lock)) { \ lock_contended(&(_lock)->dep_map, _RET_IP_); \ ____err = lock(_lock); \ } \ if (!____err) \ lock_acquired(&(_lock)->dep_map, _RET_IP_); \ ____err; \ }) #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) #define LOCK_CONTENDED_RETURN(_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) { }

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#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) { }

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#endif #endif /* __LINUX_LOCKDEP_H */

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ingo molnaringo molnar62435.58%69.52%
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nick pigginnick piggin432.45%11.59%
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john stultzjohn stultz372.11%11.59%
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