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Diffstat (limited to 'kernel')
-rw-r--r--kernel/lockdep.c26
1 files changed, 21 insertions, 5 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index d3c72ad8d09..410c3365ad8 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1372,18 +1372,32 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
struct lockdep_map *next_instance, int read)
{
struct held_lock *prev;
+ struct held_lock *nest = NULL;
int i;
for (i = 0; i < curr->lockdep_depth; i++) {
prev = curr->held_locks + i;
+
+ if (prev->instance == next->nest_lock)
+ nest = prev;
+
if (hlock_class(prev) != hlock_class(next))
continue;
+
/*
* Allow read-after-read recursion of the same
* lock class (i.e. read_lock(lock)+read_lock(lock)):
*/
if ((read == 2) && prev->read)
return 2;
+
+ /*
+ * We're holding the nest_lock, which serializes this lock's
+ * nesting behaviour.
+ */
+ if (nest)
+ return 2;
+
return print_deadlock_bug(curr, prev, next);
}
return 1;
@@ -2507,7 +2521,7 @@ EXPORT_SYMBOL_GPL(lockdep_init_map);
*/
static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check, int hardirqs_off,
- unsigned long ip)
+ struct lockdep_map *nest_lock, unsigned long ip)
{
struct task_struct *curr = current;
struct lock_class *class = NULL;
@@ -2566,6 +2580,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->class_idx = class - lock_classes + 1;
hlock->acquire_ip = ip;
hlock->instance = lock;
+ hlock->nest_lock = nest_lock;
hlock->trylock = trylock;
hlock->read = read;
hlock->check = check;
@@ -2717,7 +2732,7 @@ found_it:
if (!__lock_acquire(hlock->instance,
hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
- hlock->acquire_ip))
+ hlock->nest_lock, hlock->acquire_ip))
return 0;
}
@@ -2778,7 +2793,7 @@ found_it:
if (!__lock_acquire(hlock->instance,
hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
- hlock->acquire_ip))
+ hlock->nest_lock, hlock->acquire_ip))
return 0;
}
@@ -2915,7 +2930,8 @@ EXPORT_SYMBOL_GPL(lock_set_subclass);
* and also avoid lockdep recursion:
*/
void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
- int trylock, int read, int check, unsigned long ip)
+ int trylock, int read, int check,
+ struct lockdep_map *nest_lock, unsigned long ip)
{
unsigned long flags;
@@ -2930,7 +2946,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
current->lockdep_recursion = 1;
__lock_acquire(lock, subclass, trylock, read, check,
- irqs_disabled_flags(flags), ip);
+ irqs_disabled_flags(flags), nest_lock, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}