Re: possible circular locking dependency detected [was: linux-next: Tree for Aug 22]

Sergey Senozhatsky
2017-08-23T04:46:48Z

On (08/23/17 12:38), Boqun Feng wrote:
[..]
> diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> index 642fb5362507..a3709e15f609 100644
> --- a/kernel/locking/lockdep.c
> +++ b/kernel/locking/lockdep.c
> @@ -1156,6 +1156,23 @@ print_circular_lock_scenario(struct held_lock *src,
> __print_lock_name(target);
> printk(KERN_CONT ");\n");

KERN_CONT and "\n" should not be together. "\n" flushes the cont
buffer immediately.

-ss

> printk("\n *** DEADLOCK ***\n\n");
> + } else if (cross_lock(src->instance)) {
> + printk(" Possible unsafe locking scenario by crosslock:\n\n");
> + printk(" CPU0 CPU1\n");
> + printk(" ---- ----\n");
> + printk(" lock(");
> + __print_lock_name(target);
> + printk(KERN_CONT ");\n");
> + printk(" lock(");
> + __print_lock_name(source);
> + printk(KERN_CONT ");\n");
> + printk(" lock(");
> + __print_lock_name(parent == source ? target : parent);
> + printk(KERN_CONT ");\n");
> + printk(" unlock(");
> + __print_lock_name(source);
> + printk(KERN_CONT ");\n");
> + printk("\n *** DEADLOCK ***\n\n");
> } else {
> printk(" Possible unsafe locking scenario:\n\n");
> printk(" CPU0 CPU1\n");
> --
> 2.14.1
>