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linux-next/include/linux/lockdep.h
Peter Zijlstra e4c70a6629 lockdep, mutex: provide mutex_lock_nest_lock
In order to convert i_mmap_lock to a mutex we need a mutex equivalent to
spin_lock_nest_lock(), thus provide the mutex_lock_nest_lock() annotation.

As with spin_lock_nest_lock(), mutex_lock_nest_lock() allows annotation of
the locking pattern where an outer lock serializes the acquisition order
of nested locks.  That is, if every time you lock multiple locks A, say A1
and A2 you first acquire N, the order of acquiring A1 and A2 is
irrelevant.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:17 -07:00

555 lines
16 KiB
C

/*
* 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
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 list_head 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[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];
};
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
};
/*
* 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 {
u8 irq_context;
u8 depth;
u16 base;
struct list_head 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:2; /* see lock_acquire() comment */
unsigned int hardirqs_off:1;
unsigned int references:11; /* 32 bits */
};
/*
* 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);
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(lock, &__lockdep_no_validate__)
/*
* 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: 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);
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);
# 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) WARN_ON(debug_locks && !lockdep_is_held(l))
#else /* !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_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)
#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 { } 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:
*/
#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
#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
#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)
# define mutex_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i)
# else
# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i)
# define mutex_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, n, 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_acquire_nest(l, s, t, n, i) do { } while (0)
# define mutex_release(l, n, i) do { } while (0)
#endif
#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
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_)
# define lock_map_acquire_read(l) lock_acquire(l, 0, 0, 2, 2, NULL, _THIS_IP_)
# else
# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_)
# define lock_map_acquire_read(l) lock_acquire(l, 0, 0, 2, 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_acquire_read(l) do { } while (0)
# define lock_map_release(l) do { } while (0)
#endif
#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
#ifdef CONFIG_PROVE_RCU
extern void lockdep_rcu_dereference(const char *file, const int line);
#endif
#endif /* __LINUX_LOCKDEP_H */