/* 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_TYPES_H #define __LINUX_LOCKDEP_TYPES_H #include <linux/types.h> #define MAX_LOCKDEP_SUBCLASSES 8UL enum lockdep_wait_type { LD_WAIT_INV = 0, /* not checked, catch all */ LD_WAIT_FREE, /* wait free, rcu etc.. */ LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */ #ifdef CONFIG_PROVE_RAW_LOCK_NESTING LD_WAIT_CONFIG, /* preemptible in PREEMPT_RT, spinlock_t etc.. */ #else LD_WAIT_CONFIG = LD_WAIT_SPIN, #endif LD_WAIT_SLEEP, /* sleeping locks, mutex_t etc.. */ LD_WAIT_MAX, /* must be last */ }; enum lockdep_lock_type { LD_LOCK_NORMAL = 0, /* normal, catch all */ LD_LOCK_PERCPU, /* percpu */ LD_LOCK_WAIT_OVERRIDE, /* annotation */ LD_LOCK_MAX, }; #ifdef CONFIG_LOCKDEP /* * We'd rather not expose kernel/lockdep_states.h this wide, but we do need * the total number of states... :-( * * XXX_LOCK_USAGE_STATES is the number of lines in lockdep_states.h, for each * of those we generates 4 states, Additionally we report on USED and USED_READ. */ #define XXX_LOCK_USAGE_STATES 2 #define LOCK_TRACE_STATES (XXX_LOCK_USAGE_STATES*4 + 2) /* * NR_LOCKDEP_CACHING_CLASSES ... Number of classes * cached in the instance of lockdep_map * * Currently main class (subclass == 0) and single 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 /* * A lockdep key is associated with each lock object. For static locks we use * the lock address itself as the key. Dynamically allocated lock objects can * have a statically or dynamically allocated key. Dynamically allocated lock * keys must be registered before being used and must be unregistered before * the key memory is freed. */ struct lockdep_subclass_key { char __one_byte; } __attribute__ ((__packed__)); /* hash_entry is used to keep track of dynamically allocated keys. */ struct lock_class_key { union { struct hlist_node hash_entry; struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES]; }; }; extern struct lock_class_key __lockdep_no_validate__; extern struct lock_class_key __lockdep_no_track__; struct lock_trace; #define LOCKSTAT_POINTS 4 struct lockdep_map; typedef int (*lock_cmp_fn)(const struct lockdep_map *a, const struct lockdep_map *b); typedef void (*lock_print_fn)(const struct lockdep_map *map); /* * The lock-class itself. The order of the structure members matters. * reinit_class() zeroes the key member and all subsequent members. */ struct lock_class { /* * class-hash: */ struct hlist_node hash_entry; /* * Entry in all_lock_classes when in use. Entry in free_lock_classes * when not in use. Instances that are being freed are on one of the * zapped_classes lists. */ struct list_head lock_entry; /* * 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; const struct lockdep_subclass_key *key; lock_cmp_fn cmp_fn; lock_print_fn print_fn; unsigned int subclass; unsigned int dep_gen_id; /* * IRQ/softirq usage tracking bits: */ unsigned long usage_mask; const struct lock_trace *usage_traces[LOCK_TRACE_STATES]; const char *name; /* * Generation counter, when doing certain classes of graph walking, * to ensure that we check one node only once: */ int name_version; u8 wait_type_inner; u8 wait_type_outer; u8 lock_type; /* u8 hole; */ #ifdef CONFIG_LOCK_STAT unsigned long contention_point[LOCKSTAT_POINTS]; unsigned long contending_point[LOCKSTAT_POINTS]; #endif } __no_randomize_layout; #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]; }; void lock_stats(struct lock_class *class, struct lock_class_stats *stats); 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; u8 wait_type_outer; /* can be taken in this context */ u8 wait_type_inner; /* presents this context */ u8 lock_type; /* u8 hole; */ #ifdef CONFIG_LOCK_STAT int cpu; unsigned long ip; #endif }; struct pin_cookie { unsigned int val; }; #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 sync:1; unsigned int references:11; /* 32 bits */ unsigned int pin_count; }; #else /* !CONFIG_LOCKDEP */ /* * The class key takes no space if lockdep is disabled: */ struct lock_class_key { }; /* * The lockdep_map takes no space if lockdep is disabled: */ struct lockdep_map { }; struct pin_cookie { }; #endif /* !LOCKDEP */ #endif /* __LINUX_LOCKDEP_TYPES_H */
