diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/hardirq.h | 5 | ||||
| -rw-r--r-- | include/linux/init_task.h | 2 | ||||
| -rw-r--r-- | include/linux/lockdep.h | 347 | ||||
| -rw-r--r-- | include/linux/sched.h | 7 |
4 files changed, 359 insertions, 2 deletions
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index b1d4332b5cf0..50d8b5744cf6 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -3,6 +3,7 @@ #include <linux/preempt.h> #include <linux/smp_lock.h> +#include <linux/lockdep.h> #include <asm/hardirq.h> #include <asm/system.h> @@ -122,7 +123,7 @@ static inline void account_system_vtime(struct task_struct *tsk) */ extern void irq_exit(void); -#define nmi_enter() irq_enter() -#define nmi_exit() __irq_exit() +#define nmi_enter() do { lockdep_off(); irq_enter(); } while (0) +#define nmi_exit() do { __irq_exit(); lockdep_on(); } while (0) #endif /* LINUX_HARDIRQ_H */ diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 444a3ae0de2a..60aac2cea0cf 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -4,6 +4,7 @@ #include <linux/file.h> #include <linux/rcupdate.h> #include <linux/irqflags.h> +#include <linux/lockdep.h> #define INIT_FDTABLE \ { \ @@ -126,6 +127,7 @@ extern struct group_info init_groups; .fs_excl = ATOMIC_INIT(0), \ .pi_lock = SPIN_LOCK_UNLOCKED, \ INIT_TRACE_IRQFLAGS \ + INIT_LOCKDEP \ } diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h new file mode 100644 index 000000000000..80ec7a4dbc98 --- /dev/null +++ b/include/linux/lockdep.h @@ -0,0 +1,347 @@ +/* + * 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 + +#include <linux/linkage.h> +#include <linux/list.h> +#include <linux/debug_locks.h> +#include <linux/stacktrace.h> + +#ifdef CONFIG_LOCKDEP + +/* + * 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[MAX_LOCKDEP_SUBCLASSES]; + 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; +}; + +/* + * 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); +extern int lockdep_internal(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); + +/* + * 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) +#define lockdep_set_class_and_name(lock, key, name) \ + lockdep_init_map(&(lock)->dep_map, name, 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, unsigned long ip); + +extern void lock_release(struct lockdep_map *lock, int nested, + unsigned long ip); + +# define INIT_LOCKDEP .lockdep_recursion = 0, + +#else /* !LOCKDEP */ + +static inline void lockdep_off(void) +{ +} + +static inline void lockdep_on(void) +{ +} + +static inline int lockdep_internal(void) +{ + return 0; +} + +# 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) 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 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 { }; +#endif /* !LOCKDEP */ + +#ifdef CONFIG_TRACE_IRQFLAGS +extern void early_boot_irqs_off(void); +extern void early_boot_irqs_on(void); +#else +# define early_boot_irqs_off() do { } while (0) +# define early_boot_irqs_on() do { } while (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: + */ + +#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 */ diff --git a/include/linux/sched.h b/include/linux/sched.h index ad7a89014d29..8ebddba4448d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -886,6 +886,13 @@ struct task_struct { int hardirq_context; int softirq_context; #endif +#ifdef CONFIG_LOCKDEP +# define MAX_LOCK_DEPTH 30UL + u64 curr_chain_key; + int lockdep_depth; + struct held_lock held_locks[MAX_LOCK_DEPTH]; + unsigned int lockdep_recursion; +#endif /* journalling filesystem info */ void *journal_info; |