soc: hisilicon: kunpeng_hccs: Add the check for base address and size…

… of shared memory

If the shmem_base_addr from PCCT is zero, hccs_register_pcc_channel will
return success. And then driver will access to illegal address when send
PCC command. In addition, the size of shared memory used for communication
between driver and platform is fixed, namely 64 Bytes which is
unchangeable. So add the verification for hardening code.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>

drivers/soc/hisilicon/kunpeng_hccs.c

@@ -170,15 +170,21 @@ static int hccs_register_pcc_channel(struct hccs_dev *hdev)
 		goto err_mbx_channel_free;
 	}
 
-	if (pcc_chan->shmem_base_addr) {
-		cl_info->pcc_comm_addr = ioremap(pcc_chan->shmem_base_addr,
-						 pcc_chan->shmem_size);
-		if (!cl_info->pcc_comm_addr) {
-			dev_err(dev, "Failed to ioremap PCC communication region for channel-%u.\n",
-				hdev->chan_id);
-			rc = -ENOMEM;
-			goto err_mbx_channel_free;
-		}
+	if (!pcc_chan->shmem_base_addr ||
+	    pcc_chan->shmem_size != HCCS_PCC_SHARE_MEM_BYTES) {
+		dev_err(dev, "The base address or size (%llu) of PCC communication region is invalid.\n",
+			pcc_chan->shmem_size);
+		rc = -EINVAL;
+		goto err_mbx_channel_free;
+	}
+
+	cl_info->pcc_comm_addr = ioremap(pcc_chan->shmem_base_addr,
+					 pcc_chan->shmem_size);
+	if (!cl_info->pcc_comm_addr) {
+		dev_err(dev, "Failed to ioremap PCC communication region for channel-%u.\n",
+			hdev->chan_id);
+		rc = -ENOMEM;
+		goto err_mbx_channel_free;
 	}
 
 	return 0;