Re: [LKP] [lockdep] ef9db2383c7: WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3538 check_flags+0x22d/0x240()
From: Peter Zijlstra
Date: Wed Mar 18 2015 - 05:12:53 EST
On Wed, Mar 18, 2015 at 04:15:07PM +0800, Huang Ying wrote:
> [ 0.043211] ------------[ cut here ]------------
> [ 0.043778] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3538 check_flags+0x22d/0x240()
> [ 0.044000] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
> [ 0.044000] [<ffffffff8111659d>] check_flags+0x22d/0x240
> [ 0.044000] [<ffffffff81117636>] lock_is_held+0x36/0x90
> [ 0.044000] [<ffffffff81129ce5>] rcu_read_lock_held+0x65/0x70
> [ 0.044000] [<ffffffff81117d16>] lockdep_init_map+0x336/0x6f0
I'm not entirely sure how we get from lockdep_init_map() into
rcu_read_lock_held() without going through another call like
is_module_address().
But the error is clear enough; I added the below on top of this patch.
Thanks!
---
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2996,8 +2996,13 @@ void lockdep_init_map(struct lockdep_map
if (subclass) {
unsigned long flags;
+ if (DEBUG_LOCKS_WARN_ON(current->lockdep_recursion))
+ return;
+
raw_local_irq_save(flags);
+ current->lockdep_recursion = 1;
register_lock_class(lock, subclass, 1);
+ current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/