usage[i] = '\0';
}
+static int __print_lock_name(struct lock_class *class)
+{
+ char str[KSYM_NAME_LEN];
+ const char *name;
+
+ name = class->name;
+ if (!name)
+ name = __get_key_name(class->key, str);
+
+ return printk("%s", name);
+}
+
static void print_lock_name(struct lock_class *class)
{
char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS];
return 0;
}
+static void
+print_circular_lock_scenario(struct held_lock *src,
+ struct held_lock *tgt,
+ struct lock_list *prt)
+{
+ struct lock_class *source = hlock_class(src);
+ struct lock_class *target = hlock_class(tgt);
+ struct lock_class *parent = prt->class;
+
+ /*
+ * A direct locking problem where unsafe_class lock is taken
+ * directly by safe_class lock, then all we need to show
+ * is the deadlock scenario, as it is obvious that the
+ * unsafe lock is taken under the safe lock.
+ *
+ * But if there is a chain instead, where the safe lock takes
+ * an intermediate lock (middle_class) where this lock is
+ * not the same as the safe lock, then the lock chain is
+ * used to describe the problem. Otherwise we would need
+ * to show a different CPU case for each link in the chain
+ * from the safe_class lock to the unsafe_class lock.
+ */
+ if (parent != source) {
+ printk("Chain exists of:\n ");
+ __print_lock_name(source);
+ printk(" --> ");
+ __print_lock_name(parent);
+ printk(" --> ");
+ __print_lock_name(target);
+ printk("\n\n");
+ }
+
+ printk(" Possible unsafe locking scenario:\n\n");
+ printk(" CPU0 CPU1\n");
+ printk(" ---- ----\n");
+ printk(" lock(");
+ __print_lock_name(target);
+ printk(");\n");
+ printk(" lock(");
+ __print_lock_name(parent);
+ printk(");\n");
+ printk(" lock(");
+ __print_lock_name(target);
+ printk(");\n");
+ printk(" lock(");
+ __print_lock_name(source);
+ printk(");\n");
+ printk("\n *** DEADLOCK ***\n\n");
+}
+
/*
* When a circular dependency is detected, print the
* header first:
{
struct task_struct *curr = current;
struct lock_list *parent;
+ struct lock_list *first_parent;
int depth;
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
print_circular_bug_header(target, depth, check_src, check_tgt);
parent = get_lock_parent(target);
+ first_parent = parent;
while (parent) {
print_circular_bug_entry(parent, --depth);
}
printk("\nother info that might help us debug this:\n\n");
+ print_circular_lock_scenario(check_src, check_tgt,
+ first_parent);
+
lockdep_print_held_locks(curr);
printk("\nstack backtrace:\n");
printk("\n");
if (depth == 0 && (entry != root)) {
- printk("lockdep:%s bad BFS generated tree\n", __func__);
+ printk("lockdep:%s bad path found in chain graph\n", __func__);
break;
}
return;
}
+static void
+print_irq_lock_scenario(struct lock_list *safe_entry,
+ struct lock_list *unsafe_entry,
+ struct lock_class *prev_class,
+ struct lock_class *next_class)
+{
+ struct lock_class *safe_class = safe_entry->class;
+ struct lock_class *unsafe_class = unsafe_entry->class;
+ struct lock_class *middle_class = prev_class;
+
+ if (middle_class == safe_class)
+ middle_class = next_class;
+
+ /*
+ * A direct locking problem where unsafe_class lock is taken
+ * directly by safe_class lock, then all we need to show
+ * is the deadlock scenario, as it is obvious that the
+ * unsafe lock is taken under the safe lock.
+ *
+ * But if there is a chain instead, where the safe lock takes
+ * an intermediate lock (middle_class) where this lock is
+ * not the same as the safe lock, then the lock chain is
+ * used to describe the problem. Otherwise we would need
+ * to show a different CPU case for each link in the chain
+ * from the safe_class lock to the unsafe_class lock.
+ */
+ if (middle_class != unsafe_class) {
+ printk("Chain exists of:\n ");
+ __print_lock_name(safe_class);
+ printk(" --> ");
+ __print_lock_name(middle_class);
+ printk(" --> ");
+ __print_lock_name(unsafe_class);
+ printk("\n\n");
+ }
+
+ printk(" Possible interrupt unsafe locking scenario:\n\n");
+ printk(" CPU0 CPU1\n");
+ printk(" ---- ----\n");
+ printk(" lock(");
+ __print_lock_name(unsafe_class);
+ printk(");\n");
+ printk(" local_irq_disable();\n");
+ printk(" lock(");
+ __print_lock_name(safe_class);
+ printk(");\n");
+ printk(" lock(");
+ __print_lock_name(middle_class);
+ printk(");\n");
+ printk(" <Interrupt>\n");
+ printk(" lock(");
+ __print_lock_name(safe_class);
+ printk(");\n");
+ printk("\n *** DEADLOCK ***\n\n");
+}
+
static int
print_bad_irq_dependency(struct task_struct *curr,
struct lock_list *prev_root,
print_stack_trace(forwards_entry->class->usage_traces + bit2, 1);
printk("\nother info that might help us debug this:\n\n");
+ print_irq_lock_scenario(backwards_entry, forwards_entry,
+ hlock_class(prev), hlock_class(next));
+
lockdep_print_held_locks(curr);
printk("\nthe dependencies between %s-irq-safe lock", irqclass);
#endif
+static void
+print_deadlock_scenario(struct held_lock *nxt,
+ struct held_lock *prv)
+{
+ struct lock_class *next = hlock_class(nxt);
+ struct lock_class *prev = hlock_class(prv);
+
+ printk(" Possible unsafe locking scenario:\n\n");
+ printk(" CPU0\n");
+ printk(" ----\n");
+ printk(" lock(");
+ __print_lock_name(prev);
+ printk(");\n");
+ printk(" lock(");
+ __print_lock_name(next);
+ printk(");\n");
+ printk("\n *** DEADLOCK ***\n\n");
+ printk(" May be due to missing lock nesting notation\n\n");
+}
+
static int
print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
struct held_lock *next)
print_lock(prev);
printk("\nother info that might help us debug this:\n");
+ print_deadlock_scenario(next, prev);
lockdep_print_held_locks(curr);
printk("\nstack backtrace:\n");
struct list_head *hash_head = chainhashentry(chain_key);
struct lock_chain *chain;
struct held_lock *hlock_curr, *hlock_next;
- int i, j, n, cn;
+ int i, j;
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
}
i++;
chain->depth = curr->lockdep_depth + 1 - i;
- cn = nr_chain_hlocks;
- while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) {
- n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth);
- if (n == cn)
- break;
- cn = n;
- }
- if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
- chain->base = cn;
+ if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
+ chain->base = nr_chain_hlocks;
+ nr_chain_hlocks += chain->depth;
for (j = 0; j < chain->depth - 1; j++, i++) {
int lock_id = curr->held_locks[i].class_idx - 1;
chain_hlocks[chain->base + j] = lock_id;
#endif
}
+static void
+print_usage_bug_scenario(struct held_lock *lock)
+{
+ struct lock_class *class = hlock_class(lock);
+
+ printk(" Possible unsafe locking scenario:\n\n");
+ printk(" CPU0\n");
+ printk(" ----\n");
+ printk(" lock(");
+ __print_lock_name(class);
+ printk(");\n");
+ printk(" <Interrupt>\n");
+ printk(" lock(");
+ __print_lock_name(class);
+ printk(");\n");
+ printk("\n *** DEADLOCK ***\n\n");
+}
+
static int
print_usage_bug(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
print_irqtrace_events(curr);
printk("\nother info that might help us debug this:\n");
+ print_usage_bug_scenario(this);
+
lockdep_print_held_locks(curr);
printk("\nstack backtrace:\n");
struct held_lock *this, int forwards,
const char *irqclass)
{
+ struct lock_list *entry = other;
+ struct lock_list *middle = NULL;
+ int depth;
+
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
return 0;
printk("\n\nand interrupts could create inverse lock ordering between them.\n\n");
printk("\nother info that might help us debug this:\n");
+
+ /* Find a middle lock (if one exists) */
+ depth = get_lock_depth(other);
+ do {
+ if (depth == 0 && (entry != root)) {
+ printk("lockdep:%s bad path found in chain graph\n", __func__);
+ break;
+ }
+ middle = entry;
+ entry = get_lock_parent(entry);
+ depth--;
+ } while (entry && entry != root && (depth >= 0));
+ if (forwards)
+ print_irq_lock_scenario(root, other,
+ middle ? middle->class : root->class, other->class);
+ else
+ print_irq_lock_scenario(other, root,
+ middle ? middle->class : other->class, root->class);
+
lockdep_print_held_locks(curr);
printk("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
/*
* Hardirqs will be enabled:
*/
-void trace_hardirqs_on_caller(unsigned long ip)
+static void __trace_hardirqs_on_caller(unsigned long ip)
{
struct task_struct *curr = current;
- time_hardirqs_on(CALLER_ADDR0, ip);
-
- if (unlikely(!debug_locks || current->lockdep_recursion))
- return;
-
if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
return;
/* we'll do an OFF -> ON transition: */
curr->hardirqs_enabled = 1;
- if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
- return;
if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
return;
/*
curr->hardirq_enable_event = ++curr->irq_events;
debug_atomic_inc(hardirqs_on_events);
}
+
+void trace_hardirqs_on_caller(unsigned long ip)
+{
+ time_hardirqs_on(CALLER_ADDR0, ip);
+
+ if (unlikely(!debug_locks || current->lockdep_recursion))
+ return;
+
+ if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+ return;
+
+ current->lockdep_recursion = 1;
+ __trace_hardirqs_on_caller(ip);
+ current->lockdep_recursion = 0;
+}
EXPORT_SYMBOL(trace_hardirqs_on_caller);
void trace_hardirqs_on(void)
{
struct task_struct *curr = current;
- if (unlikely(!debug_locks))
+ if (unlikely(!debug_locks || current->lockdep_recursion))
return;
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return;
}
+ current->lockdep_recursion = 1;
/*
* We'll do an OFF -> ON transition:
*/
*/
if (curr->hardirqs_enabled)
mark_held_locks(curr, SOFTIRQ);
+ current->lockdep_recursion = 0;
}
/*
{
struct task_struct *curr = current;
- if (unlikely(!debug_locks))
+ if (unlikely(!debug_locks || current->lockdep_recursion))
return;
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
git.openpandora.org / pandora-kernel.git / blobdiff