diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index c92c29de725e..7bfeb5208177 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -1168,6 +1168,7 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
 static void hw_perf_event_update(struct perf_event *event, int flush_all)
 {
 	unsigned long long event_overflow, sampl_overflow, num_sdb;
+	struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf);
 	struct hw_perf_event *hwc = &event->hw;
 	union hws_trailer_header prev, new;
 	struct hws_trailer_entry *te;
@@ -1247,8 +1248,11 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
 	 * are dropped.
 	 * Slightly increase the interval to avoid hitting this limit.
 	 */
-	if (event_overflow)
+	if (event_overflow) {
 		SAMPL_RATE(hwc) += DIV_ROUND_UP(SAMPL_RATE(hwc), 10);
+		if (SAMPL_RATE(hwc) > cpuhw->qsi.max_sampl_rate)
+			SAMPL_RATE(hwc) = cpuhw->qsi.max_sampl_rate;
+	}
 }
 
 static inline unsigned long aux_sdb_index(struct aux_buffer *aux,
diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c
index a0dcab5dc4f2..23a32221e41a 100644
--- a/drivers/s390/crypto/zcrypt_msgtype6.c
+++ b/drivers/s390/crypto/zcrypt_msgtype6.c
@@ -953,6 +953,10 @@ static atomic_t zcrypt_step = ATOMIC_INIT(0);
 /*
  * The request distributor calls this function if it picked the CEXxC
  * device to handle a modexpo request.
+ * This function assumes that ap_msg has been initialized with
+ * ap_init_apmsg() and thus a valid buffer with the size of
+ * ap_msg->bufsize is available within ap_msg. Also the caller has
+ * to make sure ap_release_apmsg() is always called even on failure.
  * @zq: pointer to zcrypt_queue structure that identifies the
  *	CEXxC device to the request distributor
  * @mex: pointer to the modexpo request buffer
@@ -964,21 +968,17 @@ static long zcrypt_msgtype6_modexpo(struct zcrypt_queue *zq,
 	struct ap_response_type *resp_type = &ap_msg->response;
 	int rc;
 
-	ap_msg->msg = (void *)get_zeroed_page(GFP_KERNEL);
-	if (!ap_msg->msg)
-		return -ENOMEM;
-	ap_msg->bufsize = PAGE_SIZE;
 	ap_msg->receive = zcrypt_msgtype6_receive;
 	ap_msg->psmid = (((unsigned long)current->pid) << 32) +
 		atomic_inc_return(&zcrypt_step);
 	rc = icamex_msg_to_type6mex_msgx(zq, ap_msg, mex);
 	if (rc)
-		goto out_free;
+		goto out;
 	resp_type->type = CEXXC_RESPONSE_TYPE_ICA;
 	init_completion(&resp_type->work);
 	rc = ap_queue_message(zq->queue, ap_msg);
 	if (rc)
-		goto out_free;
+		goto out;
 	rc = wait_for_completion_interruptible(&resp_type->work);
 	if (rc == 0) {
 		rc = ap_msg->rc;
@@ -991,15 +991,17 @@ static long zcrypt_msgtype6_modexpo(struct zcrypt_queue *zq,
 		ap_cancel_message(zq->queue, ap_msg);
 	}
 
-out_free:
-	free_page((unsigned long)ap_msg->msg);
-	ap_msg->msg = NULL;
+out:
 	return rc;
 }
 
 /*
  * The request distributor calls this function if it picked the CEXxC
  * device to handle a modexpo_crt request.
+ * This function assumes that ap_msg has been initialized with
+ * ap_init_apmsg() and thus a valid buffer with the size of
+ * ap_msg->bufsize is available within ap_msg. Also the caller has
+ * to make sure ap_release_apmsg() is always called even on failure.
  * @zq: pointer to zcrypt_queue structure that identifies the
  *	CEXxC device to the request distributor
  * @crt: pointer to the modexpoc_crt request buffer
@@ -1011,21 +1013,17 @@ static long zcrypt_msgtype6_modexpo_crt(struct zcrypt_queue *zq,
 	struct ap_response_type *resp_type = &ap_msg->response;
 	int rc;
 
-	ap_msg->msg = (void *)get_zeroed_page(GFP_KERNEL);
-	if (!ap_msg->msg)
-		return -ENOMEM;
-	ap_msg->bufsize = PAGE_SIZE;
 	ap_msg->receive = zcrypt_msgtype6_receive;
 	ap_msg->psmid = (((unsigned long)current->pid) << 32) +
 		atomic_inc_return(&zcrypt_step);
 	rc = icacrt_msg_to_type6crt_msgx(zq, ap_msg, crt);
 	if (rc)
-		goto out_free;
+		goto out;
 	resp_type->type = CEXXC_RESPONSE_TYPE_ICA;
 	init_completion(&resp_type->work);
 	rc = ap_queue_message(zq->queue, ap_msg);
 	if (rc)
-		goto out_free;
+		goto out;
 	rc = wait_for_completion_interruptible(&resp_type->work);
 	if (rc == 0) {
 		rc = ap_msg->rc;
@@ -1038,9 +1036,7 @@ static long zcrypt_msgtype6_modexpo_crt(struct zcrypt_queue *zq,
 		ap_cancel_message(zq->queue, ap_msg);
 	}
 
-out_free:
-	free_page((unsigned long)ap_msg->msg);
-	ap_msg->msg = NULL;
+out:
 	return rc;
 }