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Diffstat (limited to 'kernel/lockdep.c')
-rw-r--r--kernel/lockdep.c73
1 files changed, 41 insertions, 32 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 805a322a565..b02032476dc 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -140,13 +140,6 @@ void lockdep_on(void)
EXPORT_SYMBOL(lockdep_on);
-int lockdep_internal(void)
-{
- return current->lockdep_recursion != 0;
-}
-
-EXPORT_SYMBOL(lockdep_internal);
-
/*
* Debugging switches:
*/
@@ -228,17 +221,15 @@ static int save_trace(struct stack_trace *trace)
trace->skip = 3;
trace->all_contexts = 0;
- /* Make sure to not recurse in case the the unwinder needs to tak
-e locks. */
- lockdep_off();
save_stack_trace(trace, NULL);
- lockdep_on();
trace->max_entries = trace->nr_entries;
nr_stack_trace_entries += trace->nr_entries;
- if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES))
+ if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES)) {
+ __raw_spin_unlock(&hash_lock);
return 0;
+ }
if (nr_stack_trace_entries == MAX_STACK_TRACE_ENTRIES) {
__raw_spin_unlock(&hash_lock);
@@ -357,7 +348,7 @@ get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4
static void print_lock_name(struct lock_class *class)
{
- char str[128], c1, c2, c3, c4;
+ char str[KSYM_NAME_LEN + 1], c1, c2, c3, c4;
const char *name;
get_usage_chars(class, &c1, &c2, &c3, &c4);
@@ -379,7 +370,7 @@ static void print_lock_name(struct lock_class *class)
static void print_lockdep_cache(struct lockdep_map *lock)
{
const char *name;
- char str[128];
+ char str[KSYM_NAME_LEN + 1];
name = lock->name;
if (!name)
@@ -449,7 +440,9 @@ static void print_lock_dependencies(struct lock_class *class, int depth)
print_lock_class_header(class, depth);
list_for_each_entry(entry, &class->locks_after, entry) {
- DEBUG_LOCKS_WARN_ON(!entry->class);
+ if (DEBUG_LOCKS_WARN_ON(!entry->class))
+ return;
+
print_lock_dependencies(entry->class, depth + 1);
printk("%*s ... acquired at:\n",depth,"");
@@ -474,7 +467,8 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
return 0;
entry->class = this;
- save_trace(&entry->trace);
+ if (!save_trace(&entry->trace))
+ return 0;
/*
* Since we never remove from the dependency list, the list can
@@ -562,8 +556,12 @@ static noinline int print_circular_bug_tail(void)
if (debug_locks_silent)
return 0;
+ /* hash_lock unlocked by the header */
+ __raw_spin_lock(&hash_lock);
this.class = check_source->class;
- save_trace(&this.trace);
+ if (!save_trace(&this.trace))
+ return 0;
+ __raw_spin_unlock(&hash_lock);
print_circular_bug_entry(&this, 0);
printk("\nother info that might help us debug this:\n\n");
@@ -575,6 +573,8 @@ static noinline int print_circular_bug_tail(void)
return 0;
}
+#define RECURSION_LIMIT 40
+
static int noinline print_infinite_recursion_bug(void)
{
__raw_spin_unlock(&hash_lock);
@@ -595,7 +595,7 @@ check_noncircular(struct lock_class *source, unsigned int depth)
debug_atomic_inc(&nr_cyclic_check_recursions);
if (depth > max_recursion_depth)
max_recursion_depth = depth;
- if (depth >= 20)
+ if (depth >= RECURSION_LIMIT)
return print_infinite_recursion_bug();
/*
* Check this lock's dependency list:
@@ -645,7 +645,7 @@ find_usage_forwards(struct lock_class *source, unsigned int depth)
if (depth > max_recursion_depth)
max_recursion_depth = depth;
- if (depth >= 20)
+ if (depth >= RECURSION_LIMIT)
return print_infinite_recursion_bug();
debug_atomic_inc(&nr_find_usage_forwards_checks);
@@ -684,7 +684,7 @@ find_usage_backwards(struct lock_class *source, unsigned int depth)
if (depth > max_recursion_depth)
max_recursion_depth = depth;
- if (depth >= 20)
+ if (depth >= RECURSION_LIMIT)
return print_infinite_recursion_bug();
debug_atomic_inc(&nr_find_usage_backwards_checks);
@@ -964,14 +964,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
&prev->class->locks_after, next->acquire_ip);
if (!ret)
return 0;
- /*
- * Return value of 2 signals 'dependency already added',
- * in that case we dont have to add the backlink either.
- */
- if (ret == 2)
- return 2;
+
ret = add_lock_to_list(next->class, prev->class,
&next->class->locks_before, next->acquire_ip);
+ if (!ret)
+ return 0;
/*
* Debugging printouts:
@@ -1023,7 +1020,8 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
* added:
*/
if (hlock->read != 2) {
- check_prev_add(curr, hlock, next);
+ if (!check_prev_add(curr, hlock, next))
+ return 0;
/*
* Stop after the first non-trylock entry,
* as non-trylock entries have added their
@@ -1079,7 +1077,8 @@ static int static_obj(void *obj)
*/
for_each_possible_cpu(i) {
start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
- end = (unsigned long) &__per_cpu_end + per_cpu_offset(i);
+ end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
+ + per_cpu_offset(i);
if ((addr >= start) && (addr < end))
return 1;
@@ -1174,11 +1173,12 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
* itself, so actual lookup of the hash should be once per lock object.
*/
static inline struct lock_class *
-register_lock_class(struct lockdep_map *lock, unsigned int subclass)
+register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
{
struct lockdep_subclass_key *key;
struct list_head *hash_head;
struct lock_class *class;
+ unsigned long flags;
class = look_up_lock_class(lock, subclass);
if (likely(class))
@@ -1200,6 +1200,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
key = lock->key->subkeys + subclass;
hash_head = classhashentry(key);
+ raw_local_irq_save(flags);
__raw_spin_lock(&hash_lock);
/*
* We have to do the hash-walk again, to avoid races
@@ -1214,6 +1215,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
*/
if (nr_lock_classes >= MAX_LOCKDEP_KEYS) {
__raw_spin_unlock(&hash_lock);
+ raw_local_irq_restore(flags);
debug_locks_off();
printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
printk("turning off the locking correctness validator.\n");
@@ -1236,17 +1238,20 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
if (verbose(class)) {
__raw_spin_unlock(&hash_lock);
+ raw_local_irq_restore(flags);
printk("\nnew class %p: %s", class->key, class->name);
if (class->name_version > 1)
printk("#%d", class->name_version);
printk("\n");
dump_stack();
+ raw_local_irq_save(flags);
__raw_spin_lock(&hash_lock);
}
out_unlock_set:
__raw_spin_unlock(&hash_lock);
+ raw_local_irq_restore(flags);
- if (!subclass)
+ if (!subclass || force)
lock->class_cache = class;
DEBUG_LOCKS_WARN_ON(class->subclass != subclass);
@@ -1725,6 +1730,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
debug_atomic_dec(&nr_unused_locks);
break;
default:
+ __raw_spin_unlock(&hash_lock);
debug_locks_off();
WARN_ON(1);
return 0;
@@ -1934,7 +1940,7 @@ void trace_softirqs_off(unsigned long ip)
* Initialize a lock instance's lock-class mapping info:
*/
void lockdep_init_map(struct lockdep_map *lock, const char *name,
- struct lock_class_key *key)
+ struct lock_class_key *key, int subclass)
{
if (unlikely(!debug_locks))
return;
@@ -1954,6 +1960,8 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
lock->name = name;
lock->key = key;
lock->class_cache = NULL;
+ if (subclass)
+ register_lock_class(lock, subclass, 1);
}
EXPORT_SYMBOL_GPL(lockdep_init_map);
@@ -1992,7 +2000,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
* Not cached yet or subclass?
*/
if (unlikely(!class)) {
- class = register_lock_class(lock, subclass);
+ class = register_lock_class(lock, subclass, 0);
if (!class)
return 0;
}
@@ -2640,6 +2648,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
}
local_irq_restore(flags);
}
+EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);
static void print_held_locks_bug(struct task_struct *curr)
{
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-28 13:09:00 +0000