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Diffstat (limited to 'kernel/lockdep.c')
-rw-r--r--kernel/lockdep.c34
1 files changed, 29 insertions, 5 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index c4cc5d1acf48..0b497dda6ae5 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1395,15 +1395,15 @@ print_shortest_lock_dependencies(struct lock_list *leaf,
static void
print_irq_lock_scenario(struct lock_list *safe_entry,
struct lock_list *unsafe_entry,
- struct held_lock *prev,
- struct held_lock *next)
+ 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 = hlock_class(prev);
+ struct lock_class *middle_class = prev_class;
if (middle_class == safe_class)
- middle_class = hlock_class(next);
+ middle_class = next_class;
/*
* A direct locking problem where unsafe_class lock is taken
@@ -1499,7 +1499,8 @@ print_bad_irq_dependency(struct task_struct *curr,
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, prev, next);
+ print_irq_lock_scenario(backwards_entry, forwards_entry,
+ hlock_class(prev), hlock_class(next));
lockdep_print_held_locks(curr);
@@ -2219,6 +2220,10 @@ print_irq_inversion_bug(struct task_struct *curr,
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;
@@ -2237,6 +2242,25 @@ print_irq_inversion_bug(struct task_struct *curr,
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");