return ret;
}
-static int lockdep_initialized;
-
unsigned long nr_list_entries;
static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
}
#ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
- cpu_lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], cpu_lock_stats);
static inline u64 lockstat_clock(void)
{
unsigned int max_lockdep_depth;
#ifdef CONFIG_DEBUG_LOCKDEP
-/*
- * We cannot printk in early bootup code. Not even early_printk()
- * might work. So we mark any initialization errors and printk
- * about it later on, in lockdep_info().
- */
-static int lockdep_init_error;
-static const char *lock_init_error;
-static unsigned long lockdep_init_trace_data[20];
-static struct stack_trace lockdep_init_trace = {
- .max_entries = ARRAY_SIZE(lockdep_init_trace_data),
- .entries = lockdep_init_trace_data,
-};
-
/*
* Various lockdep statistics:
*/
struct hlist_head *hash_head;
struct lock_class *class;
-#ifdef CONFIG_DEBUG_LOCKDEP
- /*
- * If the architecture calls into lockdep before initializing
- * the hashes then we'll warn about it later. (we cannot printk
- * right now)
- */
- if (unlikely(!lockdep_initialized)) {
- lockdep_init();
- lockdep_init_error = 1;
- lock_init_error = lock->name;
- save_stack_trace(&lockdep_init_trace);
- }
-#endif
-
if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
debug_locks_off();
printk(KERN_ERR
return lock_classes + chain_hlocks[chain->base + i];
}
+/*
+ * Returns the index of the first held_lock of the current chain
+ */
+static inline int get_first_held_lock(struct task_struct *curr,
+ struct held_lock *hlock)
+{
+ int i;
+ struct held_lock *hlock_curr;
+
+ for (i = curr->lockdep_depth - 1; i >= 0; i--) {
+ hlock_curr = curr->held_locks + i;
+ if (hlock_curr->irq_context != hlock->irq_context)
+ break;
+
+ }
+
+ return ++i;
+}
+
+/*
+ * Checks whether the chain and the current held locks are consistent
+ * in depth and also in content. If they are not it most likely means
+ * that there was a collision during the calculation of the chain_key.
+ * Returns: 0 not passed, 1 passed
+ */
+static int check_no_collision(struct task_struct *curr,
+ struct held_lock *hlock,
+ struct lock_chain *chain)
+{
+#ifdef CONFIG_DEBUG_LOCKDEP
+ int i, j, id;
+
+ i = get_first_held_lock(curr, hlock);
+
+ if (DEBUG_LOCKS_WARN_ON(chain->depth != curr->lockdep_depth - (i - 1)))
+ return 0;
+
+ for (j = 0; j < chain->depth - 1; j++, i++) {
+ id = curr->held_locks[i].class_idx - 1;
+
+ if (DEBUG_LOCKS_WARN_ON(chain_hlocks[chain->base + j] != id))
+ return 0;
+ }
+#endif
+ return 1;
+}
+
/*
* Look up a dependency chain. If the key is not present yet then
* add it and return 1 - in this case the new dependency chain is
struct lock_class *class = hlock_class(hlock);
struct hlist_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
- struct held_lock *hlock_curr;
int i, j;
/*
if (chain->chain_key == chain_key) {
cache_hit:
debug_atomic_inc(chain_lookup_hits);
+ if (!check_no_collision(curr, hlock, chain))
+ return 0;
+
if (very_verbose(class))
printk("\nhash chain already cached, key: "
"%016Lx tail class: [%p] %s\n",
chain = lock_chains + nr_lock_chains++;
chain->chain_key = chain_key;
chain->irq_context = hlock->irq_context;
- /* Find the first held_lock of current chain */
- for (i = curr->lockdep_depth - 1; i >= 0; i--) {
- hlock_curr = curr->held_locks + i;
- if (hlock_curr->irq_context != hlock->irq_context)
- break;
- }
- i++;
+ i = get_first_held_lock(curr, hlock);
chain->depth = curr->lockdep_depth + 1 - i;
if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
chain->base = nr_chain_hlocks;
{
#ifdef CONFIG_DEBUG_LOCKDEP
struct held_lock *hlock, *prev_hlock = NULL;
- unsigned int i, id;
+ unsigned int i;
u64 chain_key = 0;
for (i = 0; i < curr->lockdep_depth; i++) {
(unsigned long long)hlock->prev_chain_key);
return;
}
- id = hlock->class_idx - 1;
/*
* Whoops ran out of static storage again?
*/
- if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
+ if (DEBUG_LOCKS_WARN_ON(hlock->class_idx > MAX_LOCKDEP_KEYS))
return;
if (prev_hlock && (prev_hlock->irq_context !=
hlock->irq_context))
chain_key = 0;
- chain_key = iterate_chain_key(chain_key, id);
+ chain_key = iterate_chain_key(chain_key, hlock->class_idx);
prev_hlock = hlock;
}
if (chain_key != curr->curr_chain_key) {
struct task_struct *curr = current;
struct lock_class *class = NULL;
struct held_lock *hlock;
- unsigned int depth, id;
+ unsigned int depth;
int chain_head = 0;
int class_idx;
u64 chain_key;
* The 'key ID' is what is the most compact key value to drive
* the hash, not class->key.
*/
- id = class - lock_classes;
/*
* Whoops, we did it again.. ran straight out of our static allocation.
*/
- if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
+ if (DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS))
return 0;
chain_key = curr->curr_chain_key;
chain_key = 0;
chain_head = 1;
}
- chain_key = iterate_chain_key(chain_key, id);
+ chain_key = iterate_chain_key(chain_key, class_idx);
if (nest_lock && !__lock_is_held(nest_lock))
return print_lock_nested_lock_not_held(curr, hlock, ip);
raw_local_irq_restore(flags);
}
-void lockdep_init(void)
-{
- int i;
-
- /*
- * Some architectures have their own start_kernel()
- * code which calls lockdep_init(), while we also
- * call lockdep_init() from the start_kernel() itself,
- * and we want to initialize the hashes only once:
- */
- if (lockdep_initialized)
- return;
-
- for (i = 0; i < CLASSHASH_SIZE; i++)
- INIT_HLIST_HEAD(classhash_table + i);
-
- for (i = 0; i < CHAINHASH_SIZE; i++)
- INIT_HLIST_HEAD(chainhash_table + i);
-
- lockdep_initialized = 1;
-}
-
void __init lockdep_info(void)
{
printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
printk(" per task-struct memory footprint: %lu bytes\n",
sizeof(struct held_lock) * MAX_LOCK_DEPTH);
-
-#ifdef CONFIG_DEBUG_LOCKDEP
- if (lockdep_init_error) {
- printk("WARNING: lockdep init error: lock '%s' was acquired before lockdep_init().\n", lock_init_error);
- printk("Call stack leading to lockdep invocation was:\n");
- print_stack_trace(&lockdep_init_trace, 0);
- }
-#endif
}
static void
projects / deliverable / linux.git / blobdiff