[PATCH v2.1] audit: Only use the syscall slowpath when syscall audit rules exist

[Eric Paris]

On Mon, 2014-02-03 at 11:11 -0800, Andy Lutomirski wrote:

> +void audit_inc_n_rules()
> +{
> +	struct task_struct *p, *g;
> +	unsigned long flags;
> +
> +	read_lock_irqsave(&tasklist_lock, flags);
> +	if (audit_n_rules++ == 0) {

I know it's right, but it's too clever for me  :)  If we do end up
adding something like this Can we just do:
   if (!audit_n_rules) {}
   audit_n_rules++

I like dumb code   :)

> +		do_each_thread(g, p) {
> +			if (p->audit_context)
> +				set_tsk_thread_flag(p, TIF_SYSCALL_AUDIT);
> +		} while_each_thread(g, p);
> +	}
> +	read_unlock_irqrestore(&tasklist_lock, flags);
> +}