Q: Given the following code slice:
```
1 static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now)
2 {
3 	struct ioc *ioc = iocg->ioc;
4 	struct blkcg_gq *blkg = iocg_to_blkg(iocg);
5 	u64 tdelta, delay, new_delay;
6 	s64 vover, vover_pct;
7 	u32 hwa;
8 
9 	lockdep_assert_held(&iocg->waitq.lock);
10 
11 	/*
12 	 * If the delay is set by another CPU, we may be in the past. No need to
13 	 * change anything if so. This avoids decay calculation underflow.
14 	 */
15 	if (time_before64(now->now, iocg->delay_at))
16 		return false;
17 
18 	/* calculate the current delay in effect - 1/2 every second */
19 	tdelta = now->now - iocg->delay_at;
20 	if (iocg->delay)
21 		delay = iocg->delay >> div64_u64(tdelta, USEC_PER_SEC);
22 	else
23 		delay = 0;
24 
25 	/* calculate the new delay from the debt amount */
26 	current_hweight(iocg, &hwa, NULL);
27 	vover = atomic64_read(&iocg->vtime) +
28 		abs_cost_to_cost(iocg->abs_vdebt, hwa) - now->vnow;
29 	vover_pct = div64_s64(100 * vover,
30 			      ioc->period_us * ioc->vtime_base_rate);
31 
32 	if (vover_pct <= MIN_DELAY_THR_PCT)
33 		new_delay = 0;
34 	else if (vover_pct >= MAX_DELAY_THR_PCT)
35 		new_delay = MAX_DELAY;
36 	else
37 		new_delay = MIN_DELAY +
38 			div_u64((MAX_DELAY - MIN_DELAY) *
39 				(vover_pct - MIN_DELAY_THR_PCT),
40 				MAX_DELAY_THR_PCT - MIN_DELAY_THR_PCT);
41 
42 	/* pick the higher one and apply */
43 	if (new_delay > delay) {
44 		iocg->delay = new_delay;
45 		iocg->delay_at = now->now;
46 		delay = new_delay;
47 	}
48 
49 	if (delay >= MIN_DELAY) {
50 		if (!iocg->indelay_since)
51 			iocg->indelay_since = now->now;
52 		blkcg_set_delay(blkg, delay * NSEC_PER_USEC);
53 		return true;
54 	} else {
55 		if (iocg->indelay_since) {
56 			iocg->stat.indelay_us += now->now - iocg->indelay_since;
57 			iocg->indelay_since = 0;
58 		}
59 		iocg->delay = 0;
60 		blkcg_clear_delay(blkg);
61 		return false;
62 	}
63 }
```
which has a vulnerability among CWE-476 and among lines:
```
9 	lockdep_assert_held(&iocg->waitq.lock);
```
Please generate five possible patches for the vulnerability.