Initial import

1 files changed, 543 insertions, 0 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
new file mode 100644
index 000000000..066ba4157
--- /dev/null
+++ b/include/linux/lockdep.h
@@ -0,0 +1,543 @@
+/*
+ * Runtime locking correctness validator
+ *
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *
+ * see Documentation/locking/lockdep-design.txt for more details.
+ */
+#ifndef __LINUX_LOCKDEP_H
+#define __LINUX_LOCKDEP_H
+
+struct task_struct;
+struct lockdep_map;
+
+/* 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>
+
+/*
+ * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
+ * the total number of states... :-(
+ */
+#define XXX_LOCK_USAGE_STATES		(1+3*4)
+
+#define MAX_LOCKDEP_SUBCLASSES		8UL
+
+/*
+ * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
+ * cached in the instance of lockdep_map
+ *
+ * Currently main class (subclass == 0) and signle 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
+
+/*
+ * 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];
+};
+
+extern struct lock_class_key __lockdep_no_validate__;
+
+#define LOCKSTAT_POINTS		4
+
+/*
+ * 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;
+	unsigned int			dep_gen_id;
+
+	/*
+	 * IRQ/softirq usage tracking bits:
+	 */
+	unsigned long			usage_mask;
+	struct stack_trace		usage_traces[XXX_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;
+
+#ifdef CONFIG_LOCK_STAT
+	unsigned long			contention_point[LOCKSTAT_POINTS];
+	unsigned long			contending_point[LOCKSTAT_POINTS];
+#endif
+};
+
+#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[4];
+	unsigned long			contending_point[4];
+	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];
+};
+
+struct lock_class_stats lock_stats(struct lock_class *class);
+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;
+#ifdef CONFIG_LOCK_STAT
+	int				cpu;
+	unsigned long			ip;
+#endif
+};
+
+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 stack_trace		trace;
+	int				distance;
+
+	/*
+	 * 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;
+};
+
+/*
+ * We record lock dependency chains, so that we can cache them:
+ */
+struct lock_chain {
+	u8				irq_context;
+	u8				depth;
+	u16				base;
+	struct list_head		entry;
+	u64				chain_key;
+};
+
+#define MAX_LOCKDEP_KEYS_BITS		13
+/*
+ * Subtract one because we offset hlock->class_idx by 1 in order
+ * to make 0 mean no class. This avoids overflowing the class_idx
+ * bitfield and hitting the BUG in hlock_class().
+ */
+#define MAX_LOCKDEP_KEYS		((1UL << MAX_LOCKDEP_KEYS_BITS) - 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
+	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 */
+};
+
+/*
+ * 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 asmlinkage void lockdep_sys_exit(void);
+
+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);
+
+/*
+ * 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), }
+
+/*
+ * 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)
+
+#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, int nested,
+			 unsigned long ip);
+
+#define lockdep_is_held(lock)	lock_is_held(&(lock)->dep_map)
+
+extern int lock_is_held(struct lockdep_map *lock);
+
+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 lockdep_set_current_reclaim_state(gfp_t gfp_mask);
+extern void lockdep_clear_current_reclaim_state(void);
+extern void lockdep_trace_alloc(gfp_t mask);
+
+# define INIT_LOCKDEP				.lockdep_recursion = 0, .lockdep_reclaim_gfp = 0,
+
+#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_once(l)	do {				\
+		WARN_ON_ONCE(debug_locks && !lockdep_is_held(l));	\
+	} while (0)
+
+#define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)
+
+#else /* !CONFIG_LOCKDEP */
+
+static inline void lockdep_off(void)
+{
+}
+
+static inline void lockdep_on(void)
+{
+}
+
+# define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
+# define lock_release(l, n, 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_set_current_reclaim_state(g)	do { } while (0)
+# define lockdep_clear_current_reclaim_state()	do { } while (0)
+# define lockdep_trace_alloc(g)			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)(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 INIT_LOCKDEP
+# 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)
+/*
+ * The class key takes no space if lockdep is disabled:
+ */
+struct lock_class_key { };
+
+#define lockdep_depth(tsk)	(0)
+
+#define lockdep_assert_held(l)			do { (void)(l); } while (0)
+#define lockdep_assert_held_once(l)		do { (void)(l); } while (0)
+
+#define lockdep_recursing(tsk)			(0)
+
+#endif /* !LOCKDEP */
+
+#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)
+
+#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)
+
+#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_TRACE_IRQFLAGS
+extern void print_irqtrace_events(struct task_struct *curr);
+#else
+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:
+ */
+
+#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, n, i)			lock_release(l, n, i)
+
+#define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
+#define rwlock_acquire_read(l, s, t, i)		lock_acquire_shared_recursive(l, s, t, NULL, i)
+#define rwlock_release(l, n, i)			lock_release(l, n, 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, n, i)		lock_release(l, n, 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, n, i)			lock_release(l, n, 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, n, i)			lock_release(l, n, 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, 1, _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, 0, _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, 0, _THIS_IP_);			\
+} while (0)
+#else
+# define might_lock(lock) do { } while (0)
+# define might_lock_read(lock) 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 */