1 files changed, 347 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
new file mode 100644
index 00000000000..80ec7a4dbc9
--- /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 */