diff options
Diffstat (limited to '')
-rw-r--r-- | include/linux/lockdep.h | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h new file mode 100644 index 000000000..2c2586312 --- /dev/null +++ b/include/linux/lockdep.h @@ -0,0 +1,647 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * 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.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; + +/* 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> + +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; +}; + +#define MAX_LOCKDEP_KEYS_BITS 13 +#define MAX_LOCKDEP_KEYS (1UL << MAX_LOCKDEP_KEYS_BITS) +#define INITIAL_CHAIN_KEY -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 + /* + * class_idx is zero-indexed; it points to the element in + * lock_classes this held lock instance belongs to. class_idx is in + * the range from 0 to (MAX_LOCKDEP_KEYS-1) inclusive. + */ + 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_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 recrursion 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, (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); + +/* + * 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); + +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_held(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held(l)); \ + } while (0) + +#define lockdep_assert_held_write(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ + } while (0) + +#define lockdep_assert_held_read(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held_type(l, 1)); \ + } 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_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, k, s, 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) + +#define lockdep_is_held_type(l, r) (1) + +#define lockdep_assert_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_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) + +#endif /* !LOCKDEP */ + +enum xhlock_context_t { + XHLOCK_HARD, + XHLOCK_SOFT, + XHLOCK_CTX_NR, +}; + +#define lockdep_init_map_crosslock(m, n, k, s) do {} while (0) +/* + * 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_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_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_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_) + +#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_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) + +#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_preemption_enabled() do { } while (0) +# define lockdep_assert_preemption_disabled() 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 */ |