Re: [PATCH v2 1/4] seccomp: add a return code to trap to userspace

Oleg Nesterov
2018-05-17T15:33:29Z

I didn't read this series yet, and I don't even understand what are you
trying to do, just one question...

On 05/17, Tycho Andersen wrote:
>
> +static struct file *init_listener(struct task_struct *task,
> + struct seccomp_filter *filter)
> +{
> + struct file *ret = ERR_PTR(-EBUSY);
> + struct seccomp_filter *cur;
> + bool have_listener = false;
> +
> + for (cur = task->seccomp.filter; cur; cur = cur->prev) {
> + mutex_lock(&cur->notify_lock);

Did you test this patch with CONFIG_LOCKDEP ?

>From lockdep pov this loop tries to take the same lock twice or more, it shoul
complain.

Oleg.