068135e635
Generate locking graph information into /proc/lockdep, for lock hierarchy documentation and visualization purposes. sample output: c089fd5c OPS: 138 FD: 14 BD: 1 --..: &tty->termios_mutex -> [c07a3430] tty_ldisc_lock -> [c07a37f0] &port_lock_key -> [c07afdc0] &rq->rq_lock_key#2 The lock classes listed are all the first-hop lock dependencies that lockdep has seen so far. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
373 lines
10 KiB
C
373 lines
10 KiB
C
/*
|
|
* Runtime locking correctness validator
|
|
*
|
|
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
|
|
*
|
|
* see Documentation/lockdep-design.txt for more details.
|
|
*/
|
|
#ifndef __LINUX_LOCKDEP_H
|
|
#define __LINUX_LOCKDEP_H
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/list.h>
|
|
#include <linux/debug_locks.h>
|
|
#include <linux/stacktrace.h>
|
|
|
|
/*
|
|
* Lock-class usage-state bits:
|
|
*/
|
|
enum lock_usage_bit
|
|
{
|
|
LOCK_USED = 0,
|
|
LOCK_USED_IN_HARDIRQ,
|
|
LOCK_USED_IN_SOFTIRQ,
|
|
LOCK_ENABLED_SOFTIRQS,
|
|
LOCK_ENABLED_HARDIRQS,
|
|
LOCK_USED_IN_HARDIRQ_READ,
|
|
LOCK_USED_IN_SOFTIRQ_READ,
|
|
LOCK_ENABLED_SOFTIRQS_READ,
|
|
LOCK_ENABLED_HARDIRQS_READ,
|
|
LOCK_USAGE_STATES
|
|
};
|
|
|
|
/*
|
|
* Usage-state bitmasks:
|
|
*/
|
|
#define LOCKF_USED (1 << LOCK_USED)
|
|
#define LOCKF_USED_IN_HARDIRQ (1 << LOCK_USED_IN_HARDIRQ)
|
|
#define LOCKF_USED_IN_SOFTIRQ (1 << LOCK_USED_IN_SOFTIRQ)
|
|
#define LOCKF_ENABLED_HARDIRQS (1 << LOCK_ENABLED_HARDIRQS)
|
|
#define LOCKF_ENABLED_SOFTIRQS (1 << LOCK_ENABLED_SOFTIRQS)
|
|
|
|
#define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS | LOCKF_ENABLED_SOFTIRQS)
|
|
#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
|
|
|
|
#define LOCKF_USED_IN_HARDIRQ_READ (1 << LOCK_USED_IN_HARDIRQ_READ)
|
|
#define LOCKF_USED_IN_SOFTIRQ_READ (1 << LOCK_USED_IN_SOFTIRQ_READ)
|
|
#define LOCKF_ENABLED_HARDIRQS_READ (1 << LOCK_ENABLED_HARDIRQS_READ)
|
|
#define LOCKF_ENABLED_SOFTIRQS_READ (1 << LOCK_ENABLED_SOFTIRQS_READ)
|
|
|
|
#define LOCKF_ENABLED_IRQS_READ \
|
|
(LOCKF_ENABLED_HARDIRQS_READ | LOCKF_ENABLED_SOFTIRQS_READ)
|
|
#define LOCKF_USED_IN_IRQ_READ \
|
|
(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
|
|
|
|
#define MAX_LOCKDEP_SUBCLASSES 8UL
|
|
|
|
/*
|
|
* 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];
|
|
};
|
|
|
|
/*
|
|
* 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;
|
|
|
|
/*
|
|
* IRQ/softirq usage tracking bits:
|
|
*/
|
|
unsigned long usage_mask;
|
|
struct stack_trace usage_traces[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;
|
|
};
|
|
|
|
/*
|
|
* 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;
|
|
};
|
|
|
|
/*
|
|
* 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;
|
|
};
|
|
|
|
/*
|
|
* We record lock dependency chains, so that we can cache them:
|
|
*/
|
|
struct lock_chain {
|
|
struct list_head entry;
|
|
u64 chain_key;
|
|
};
|
|
|
|
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;
|
|
struct lock_class *class;
|
|
unsigned long acquire_ip;
|
|
struct lockdep_map *instance;
|
|
|
|
/*
|
|
* 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:
|
|
*/
|
|
int irq_context;
|
|
int trylock;
|
|
int read;
|
|
int check;
|
|
int hardirqs_off;
|
|
};
|
|
|
|
/*
|
|
* 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_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);
|
|
|
|
/*
|
|
* 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)
|
|
|
|
/*
|
|
* 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, unsigned long ip);
|
|
|
|
extern void lock_release(struct lockdep_map *lock, int nested,
|
|
unsigned long ip);
|
|
|
|
# define INIT_LOCKDEP .lockdep_recursion = 0,
|
|
|
|
#define lockdep_depth(tsk) ((tsk)->lockdep_depth)
|
|
|
|
#else /* !LOCKDEP */
|
|
|
|
static inline void lockdep_off(void)
|
|
{
|
|
}
|
|
|
|
static inline void lockdep_on(void)
|
|
{
|
|
}
|
|
|
|
# define lock_acquire(l, s, t, r, c, i) do { } while (0)
|
|
# define lock_release(l, n, i) 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)(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); } 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 INIT_LOCKDEP
|
|
# define lockdep_reset() do { debug_locks = 1; } while (0)
|
|
# define lockdep_free_key_range(start, size) do { } while (0)
|
|
/*
|
|
* The class key takes no space if lockdep is disabled:
|
|
*/
|
|
struct lock_class_key { };
|
|
|
|
#define lockdep_depth(tsk) (0)
|
|
|
|
#endif /* !LOCKDEP */
|
|
|
|
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
|
|
extern void early_init_irq_lock_class(void);
|
|
#else
|
|
static inline void early_init_irq_lock_class(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#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
|
|
|
|
/*
|
|
* 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, i)
|
|
# else
|
|
# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, 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, i)
|
|
# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, i)
|
|
# else
|
|
# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
|
|
# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, 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, i)
|
|
# else
|
|
# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, 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
|
|
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
# ifdef CONFIG_PROVE_LOCKING
|
|
# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
|
|
# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, i)
|
|
# else
|
|
# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
|
|
# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, 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
|
|
|
|
#endif /* __LINUX_LOCKDEP_H */
|