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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Runtime locking correctness validator
*
* Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <[email protected]>
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
*
* see Documentation/locking/lockdep-design.rst for more details.
*/
#ifndef __LINUX_LOCKDEP_H
#define __LINUX_LOCKDEP_H
#include <linux/lockdep_types.h>
#include <linux/smp.h>
#include <asm/percpu.h>
struct task_struct;
#ifdef CONFIG_LOCKDEP
#include <linux/linkage.h>
#include <linux/list.h>
#include <linux/debug_locks.h>
#include <linux/stacktrace.h>
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 lock_class *links_to;
const struct lock_trace *trace;
u16 distance;
/* bitmap of different dependencies from head to this */
u8 dep;
/* used by BFS to record whether "prev -> this" only has -(*R)-> */
u8 only_xr;
/*
* 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;
};
/**
* struct lock_chain - lock dependency chain record
*
* @irq_context: the same as irq_context in held_lock below
* @depth: the number of held locks in this chain
* @base: the index in chain_hlocks for this chain
* @entry: the collided lock chains in lock_chain hash list
* @chain_key: the hash key of this lock_chain
*/
struct lock_chain {
/* see BUILD_BUG_ON()s in add_chain_cache() */
unsigned int irq_context : 2,
depth : 6,
base : 24;
/* 4 byte hole */
struct hlist_node entry;
u64 chain_key;
};
/*
* Initialization, self-test and debugging-output methods:
*/
extern void lockdep_init(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_set_selftest_task(struct task_struct *task);
extern void lockdep_init_task(struct task_struct *task);
/*
* Split the recursion counter in two to readily detect 'off' vs recursion.
*/
#define LOCKDEP_RECURSION_BITS 16
#define LOCKDEP_OFF (1U << LOCKDEP_RECURSION_BITS)
#define LOCKDEP_RECURSION_MASK (LOCKDEP_OFF - 1)
/*
* lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due
* to header dependencies.
*/
#define lockdep_off() \
do { \
current->lockdep_recursion += LOCKDEP_OFF; \
} while (0)
#define lockdep_on() \
do { \
current->lockdep_recursion -= LOCKDEP_OFF; \
} while (0)
extern void lockdep_register_key(struct lock_class_key *key);
extern void lockdep_unregister_key(struct lock_class_key *key);
/*
* 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_type(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass, u8 inner, u8 outer, u8 lock_type);
static inline void
lockdep_init_map_waits(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass, u8 inner, u8 outer)
{
lockdep_init_map_type(lock, name, key, subclass, inner, outer, LD_LOCK_NORMAL);
}
static inline void
lockdep_init_map_wait(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass, u8 inner)
{
lockdep_init_map_waits(lock, name, key, subclass, inner, LD_WAIT_INV);
}
static inline void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass)
{
lockdep_init_map_wait(lock, name, key, subclass, LD_WAIT_INV);
}
/*
* 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_type(&(lock)->dep_map, #key, key, 0, \
(lock)->dep_map.wait_type_inner, \
(lock)->dep_map.wait_type_outer, \
(lock)->dep_map.lock_type)
#define lockdep_set_class_and_name(lock, key, name) \
lockdep_init_map_type(&(lock)->dep_map, name, key, 0, \
(lock)->dep_map.wait_type_inner, \
(lock)->dep_map.wait_type_outer, \
(lock)->dep_map.lock_type)
#define lockdep_set_class_and_subclass(lock, key, sub) \
lockdep_init_map_type(&(lock)->dep_map, #key, key, sub, \
(lock)->dep_map.wait_type_inner, \
(lock)->dep_map.wait_type_outer, \
(lock)->dep_map.lock_type)
#define lockdep_set_subclass(lock, sub) \
lockdep_init_map_type(&(lock)->dep_map, (lock)->dep_map.name, (lock)->dep_map.key, sub,\
(lock)->dep_map.wait_type_inner, \
(lock)->dep_map.wait_type_outer, \
(lock)->dep_map.lock_type)
#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, unsigned long ip);
extern void lock_sync(struct lockdep_map *lock, unsigned int subclass,
int read, int check, struct lockdep_map *nest_lock,
unsigned long ip);
/* lock_is_held_type() returns */
#define LOCK_STATE_UNKNOWN -1
#define LOCK_STATE_NOT_HELD 0
#define LOCK_STATE_HELD 1
/*
* Same "read" as for lock_acquire(), except -1 means any.
*/
extern int lock_is_held_type(const struct lockdep_map *lock, int read);
static inline int lock_is_held(const struct lockdep_map *lock)
{
return lock_is_held_type(lock, -1);
}
#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map)
#define lockdep_is_held_type(lock, r) lock_is_held_type(&(lock)->dep_map, (r))
extern void lock_set_class(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, unsigned int subclass,
unsigned long ip);
#define lock_set_novalidate_class(l, n, i) \
lock_set_class(l, n, &__lockdep_no_validate__, 0, i)
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 lock_downgrade(struct lockdep_map *lock, unsigned long ip);
#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 lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
#define lockdep_assert(cond) \
do { WARN_ON(debug_locks && !(cond)); } while (0)
#define lockdep_assert_once(cond) \
do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
#define lockdep_assert_held(l) \
lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
#define lockdep_assert_not_held(l) \
lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
#define lockdep_assert_held_write(l) \
lockdep_assert(lockdep_is_held_type(l, 0))
#define lockdep_assert_held_read(l) \
lockdep_assert(lockdep_is_held_type(l, 1))
#define lockdep_assert_held_once(l) \
lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
#define lockdep_assert_none_held_once() \
lockdep_assert_once(!current->lockdep_depth)
#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))
/*
* Must use lock_map_aquire_try() with override maps to avoid
* lockdep thinking they participate in the block chain.
*/
#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type) \
struct lockdep_map _name = { \
.name = #_name "-wait-type-override", \
.wait_type_inner = _wait_type, \
.lock_type = LD_LOCK_WAIT_OVERRIDE, }
#else /* !CONFIG_LOCKDEP */
static inline void lockdep_init_task(struct task_struct *task)
{
}
static inline void lockdep_off(void)
{
}
static inline void lockdep_on(void)
{
}
static inline void lockdep_set_selftest_task(struct task_struct *task)
{
}
# define lock_acquire(l, s, t, r, c, n, i) do { } while (0)
# define lock_release(l, i) do { } while (0)
# define lock_downgrade(l, i) do { } while (0)
# define lock_set_class(l, n, key, s, i) do { (void)(key); } while (0)
# define lock_set_novalidate_class(l, n, i) do { } while (0)
# define lock_set_subclass(l, s, i) do { } while (0)
# define lockdep_init() do { } while (0)
# define lockdep_init_map_type(lock, name, key, sub, inner, outer, type) \
do { (void)(name); (void)(key); } while (0)
# define lockdep_init_map_waits(lock, name, key, sub, inner, outer) \
do { (void)(name); (void)(key); } while (0)
# define lockdep_init_map_wait(lock, name, key, sub, inner) \
do { (void)(name); (void)(key); } 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 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)
static inline void lockdep_register_key(struct lock_class_key *key)
{
}
static inline void lockdep_unregister_key(struct lock_class_key *key)
{
}
#define lockdep_depth(tsk) (0)
/*
* Dummy forward declarations, allow users to write less ifdef-y code
* and depend on dead code elimination.
*/
extern int lock_is_held(const void *);
extern int lockdep_is_held(const void *);
#define lockdep_is_held_type(l, r) (1)
#define lockdep_assert(c) do { } while (0)
#define lockdep_assert_once(c) do { } while (0)
#define lockdep_assert_held(l) do { (void)(l); } while (0)
#define lockdep_assert_not_held(l) do { (void)(l); } while (0)
#define lockdep_assert_held_write(l) do { (void)(l); } while (0)
#define lockdep_assert_held_read(l) do { (void)(l); } while (0)
#define lockdep_assert_held_once(l) do { (void)(l); } while (0)
#define lockdep_assert_none_held_once() do { } while (0)
#define lockdep_recursing(tsk) (0)
#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)
#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type) \
struct lockdep_map __maybe_unused _name = {}
#endif /* !LOCKDEP */
#ifdef CONFIG_PROVE_LOCKING
void lockdep_set_lock_cmp_fn(struct lockdep_map *, lock_cmp_fn, lock_print_fn);
#define lock_set_cmp_fn(lock, ...) lockdep_set_lock_cmp_fn(&(lock)->dep_map, __VA_ARGS__)
#else
#define lock_set_cmp_fn(lock, ...) do { } while (0)
#endif
enum xhlock_context_t {
XHLOCK_HARD,
XHLOCK_SOFT,
XHLOCK_CTX_NR,
};
/*
* 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), }
static inline void lockdep_invariant_state(bool force) {}
static inline void lockdep_free_task(struct task_struct *task) {}
#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_PROVE_LOCKING
extern void print_irqtrace_events(struct task_struct *curr);
#else
static inline void print_irqtrace_events(struct task_struct *curr)
{
}
#endif
/* Variable used to make lockdep treat read_lock() as recursive in selftests */
#ifdef CONFIG_DEBUG_LOCKING_API_SELFTESTS
extern unsigned int force_read_lock_recursive;
#else /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
#define force_read_lock_recursive 0
#endif /* CONFIG_DEBUG_LOCKING_API_SELFTESTS */
#ifdef CONFIG_LOCKDEP
extern bool read_lock_is_recursive(void);
#else /* CONFIG_LOCKDEP */
/* If !LOCKDEP, the value is meaningless */
#define read_lock_is_recursive() 0
#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, i) lock_release(l, i)
#define rwlock_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i)
#define rwlock_acquire_read(l, s, t, i) \
do { \
if (read_lock_is_recursive()) \
lock_acquire_shared_recursive(l, s, t, NULL, i); \
else \
lock_acquire_shared(l, s, t, NULL, i); \
} while (0)
#define rwlock_release(l, i) lock_release(l, 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, i) lock_release(l, 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, i) lock_release(l, 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, i) lock_release(l, i)
#define lock_map_acquire(l) lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
#define lock_map_acquire_try(l) lock_acquire_exclusive(l, 0, 1, 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, _THIS_IP_)
#define lock_map_sync(l) lock_sync(l, 0, 0, 1, NULL, _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, _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, _THIS_IP_); \
} while (0)
# define might_lock_nested(lock, subclass) \
do { \
typecheck(struct lockdep_map *, &(lock)->dep_map); \
lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL, \
_THIS_IP_); \
lock_release(&(lock)->dep_map, _THIS_IP_); \
} while (0)
DECLARE_PER_CPU(int, hardirqs_enabled);
DECLARE_PER_CPU(int, hardirq_context);
DECLARE_PER_CPU(unsigned int, lockdep_recursion);
#define __lockdep_enabled (debug_locks && !this_cpu_read(lockdep_recursion))
#define lockdep_assert_irqs_enabled() \
do { \
WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirqs_enabled)); \
} while (0)
#define lockdep_assert_irqs_disabled() \
do { \
WARN_ON_ONCE(__lockdep_enabled && this_cpu_read(hardirqs_enabled)); \
} while (0)
#define lockdep_assert_in_irq() \
do { \
WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
} while (0)
#define lockdep_assert_no_hardirq() \
do { \
WARN_ON_ONCE(__lockdep_enabled && (this_cpu_read(hardirq_context) || \
!this_cpu_read(hardirqs_enabled))); \
} while (0)
#define lockdep_assert_preemption_enabled() \
do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
__lockdep_enabled && \
(preempt_count() != 0 || \
!this_cpu_read(hardirqs_enabled))); \
} while (0)
#define lockdep_assert_preemption_disabled() \
do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
__lockdep_enabled && \
(preempt_count() == 0 && \
this_cpu_read(hardirqs_enabled))); \
} while (0)
/*
* Acceptable for protecting per-CPU resources accessed from BH.
* Much like in_softirq() - semantics are ambiguous, use carefully.
*/
#define lockdep_assert_in_softirq() \
do { \
WARN_ON_ONCE(__lockdep_enabled && \
(!in_softirq() || in_irq() || in_nmi())); \
} while (0)
#else
# define might_lock(lock) do { } while (0)
# define might_lock_read(lock) do { } while (0)
# define might_lock_nested(lock, subclass) do { } while (0)
# define lockdep_assert_irqs_enabled() do { } while (0)
# define lockdep_assert_irqs_disabled() do { } while (0)
# define lockdep_assert_in_irq() do { } while (0)
# define lockdep_assert_no_hardirq() do { } while (0)
# define lockdep_assert_preemption_enabled() do { } while (0)
# define lockdep_assert_preemption_disabled() do { } while (0)
# define lockdep_assert_in_softirq() do { } while (0)
#endif
#ifdef CONFIG_PROVE_RAW_LOCK_NESTING
# define lockdep_assert_RT_in_threaded_ctx() do { \
WARN_ONCE(debug_locks && !current->lockdep_recursion && \
lockdep_hardirq_context() && \
!(current->hardirq_threaded || current->irq_config), \
"Not in threaded context on PREEMPT_RT as expected\n"); \
} while (0)
#else
# define lockdep_assert_RT_in_threaded_ctx() 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 */
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