v4.19.13 snapshot.
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
new file mode 100644
index 0000000..b0d0b51
--- /dev/null
+++ b/include/linux/lockdep.h
@@ -0,0 +1,627 @@
+/* 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.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;
+
+#define MAX_LOCKDEP_SUBCLASSES 8UL
+
+#include <linux/types.h>
+
+#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+2*4)
+
+/*
+ * 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 hlist_node 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[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];
+};
+
+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 {
+ /* see BUILD_BUG_ON()s in lookup_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
+/*
+ * 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 */
+ 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_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);
+
+/*
+ * 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);
+
+/*
+ * 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);
+
+struct pin_cookie { unsigned int val; };
+
+#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_exclusive(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_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_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(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)
+/*
+ * 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 { };
+
+#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_exclusive(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)
+
+struct pin_cookie { };
+
+#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_init_task(struct task_struct *task) {}
+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
+
+/*
+ * 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)
+
+#define lockdep_assert_irqs_enabled() do { \
+ WARN_ONCE(debug_locks && !current->lockdep_recursion && \
+ !current->hardirqs_enabled, \
+ "IRQs not enabled as expected\n"); \
+ } while (0)
+
+#define lockdep_assert_irqs_disabled() do { \
+ WARN_ONCE(debug_locks && !current->lockdep_recursion && \
+ current->hardirqs_enabled, \
+ "IRQs not disabled as expected\n"); \
+ } while (0)
+
+#else
+# define might_lock(lock) do { } while (0)
+# define might_lock_read(lock) do { } while (0)
+# define lockdep_assert_irqs_enabled() do { } while (0)
+# define lockdep_assert_irqs_disabled() 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 */