diff options
| -rw-r--r-- | include/linux/lockdep.h | 1 | ||||
| -rw-r--r-- | kernel/lockdep.c | 19 | ||||
| -rw-r--r-- | kernel/lockdep_proc.c | 41 |
3 files changed, 42 insertions, 19 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index ea097dddc44f..7e1160dde5e7 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -132,6 +132,7 @@ struct lock_list { struct list_head entry; struct lock_class *class; struct stack_trace trace; + int distance; }; /* diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 2d616f4d853c..592c576d77a7 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -490,7 +490,7 @@ static void print_lock_dependencies(struct lock_class *class, int depth) * Add a new dependency to the head of the list: */ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, - struct list_head *head, unsigned long ip) + struct list_head *head, unsigned long ip, int distance) { struct lock_list *entry; /* @@ -502,6 +502,7 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, return 0; entry->class = this; + entry->distance = distance; if (!save_trace(&entry->trace)) return 0; @@ -906,7 +907,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next, */ static int check_prev_add(struct task_struct *curr, struct held_lock *prev, - struct held_lock *next) + struct held_lock *next, int distance) { struct lock_list *entry; int ret; @@ -984,8 +985,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * L2 added to its dependency list, due to the first chain.) */ list_for_each_entry(entry, &prev->class->locks_after, entry) { - if (entry->class == next->class) + if (entry->class == next->class) { + if (distance == 1) + entry->distance = 1; return 2; + } } /* @@ -993,12 +997,13 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * to the previous lock's dependency list: */ ret = add_lock_to_list(prev->class, next->class, - &prev->class->locks_after, next->acquire_ip); + &prev->class->locks_after, next->acquire_ip, distance); + if (!ret) return 0; ret = add_lock_to_list(next->class, prev->class, - &next->class->locks_before, next->acquire_ip); + &next->class->locks_before, next->acquire_ip, distance); if (!ret) return 0; @@ -1046,13 +1051,14 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) goto out_bug; for (;;) { + int distance = curr->lockdep_depth - depth + 1; hlock = curr->held_locks + depth-1; /* * Only non-recursive-read entries get new dependencies * added: */ if (hlock->read != 2) { - if (!check_prev_add(curr, hlock, next)) + if (!check_prev_add(curr, hlock, next, distance)) return 0; /* * Stop after the first non-trylock entry, @@ -2779,4 +2785,3 @@ void debug_show_held_locks(struct task_struct *task) } EXPORT_SYMBOL_GPL(debug_show_held_locks); - diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index b554b40a4aa6..57a547a2da3f 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -77,12 +77,29 @@ static unsigned long count_backward_deps(struct lock_class *class) return ret; } +static void print_name(struct seq_file *m, struct lock_class *class) +{ + char str[128]; + const char *name = class->name; + + if (!name) { + name = __get_key_name(class->key, str); + seq_printf(m, "%s", name); + } else{ + seq_printf(m, "%s", name); + if (class->name_version > 1) + seq_printf(m, "#%d", class->name_version); + if (class->subclass) + seq_printf(m, "/%d", class->subclass); + } +} + static int l_show(struct seq_file *m, void *v) { unsigned long nr_forward_deps, nr_backward_deps; struct lock_class *class = m->private; - char str[128], c1, c2, c3, c4; - const char *name; + struct lock_list *entry; + char c1, c2, c3, c4; seq_printf(m, "%p", class->key); #ifdef CONFIG_DEBUG_LOCKDEP @@ -97,16 +114,16 @@ static int l_show(struct seq_file *m, void *v) get_usage_chars(class, &c1, &c2, &c3, &c4); seq_printf(m, " %c%c%c%c", c1, c2, c3, c4); - name = class->name; - if (!name) { - name = __get_key_name(class->key, str); - seq_printf(m, ": %s", name); - } else{ - seq_printf(m, ": %s", name); - if (class->name_version > 1) - seq_printf(m, "#%d", class->name_version); - if (class->subclass) - seq_printf(m, "/%d", class->subclass); + seq_printf(m, ": "); + print_name(m, class); + seq_puts(m, "\n"); + + list_for_each_entry(entry, &class->locks_after, entry) { + if (entry->distance == 1) { + seq_printf(m, " -> [%p] ", entry->class); + print_name(m, entry->class); + seq_puts(m, "\n"); + } } seq_puts(m, "\n"); |