Subject: [PATCH v9 09/11] seccomp: introduce writer locking

From: [email-masked] (Oleg Nesterov)
Date: Wed, 9 Jul 2014 20:59:36 +0200

On 06/27, Kees Cook wrote:
>
>  void put_seccomp_filter(struct task_struct *tsk)
>  {
> -	struct seccomp_filter *orig = tsk->seccomp.filter;
> +	struct seccomp_filter *orig = smp_load_acquire(&tsk->seccomp.filter);
>  	/* Clean up single-reference branches iteratively. */
>  	while (orig && atomic_dec_and_test(&orig->usage)) {

And this smp_load_acquire() looks unnecessary. atomic_dec_and_test()
is a barrier.

Oleg.