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

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.