serial: icom: move array overflow checks earlier

This code does an annoying thing where it writes to the array and then
checks later for array overflows.  I don't know if it's actually
possible to overflow but let's check before using the array index.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 48 insertions, 41 deletions

diff --git a/drivers/tty/serial/icom.c b/drivers/tty/serial/icom.c
index 7c9a06732ae5..d98e43348970 100644
--- a/drivers/tty/serial/icom.c
+++ b/drivers/tty/serial/icom.c
@@ -297,25 +297,25 @@ static void stop_processor(struct icom_port *icom_port)
         spin_lock_irqsave(&icom_lock, flags);
 
         port = icom_port->port;
+        if (port >= ARRAY_SIZE(stop_proc)) {
+                dev_err(&icom_port->adapter->pci_dev->dev,
+                        "Invalid port assignment\n");
+                goto unlock;
+        }
+
         if (port == 0 || port == 1)
                 stop_proc[port].global_control_reg = &icom_port->global_reg->control;
         else
                 stop_proc[port].global_control_reg = &icom_port->global_reg->control_2;
 
+        temp = readl(stop_proc[port].global_control_reg);
+        temp = (temp & ~start_proc[port].processor_id) | stop_proc[port].processor_id;
+        writel(temp, stop_proc[port].global_control_reg);
 
-        if (port < 4) {
-                temp = readl(stop_proc[port].global_control_reg);
-                temp =
-                        (temp & ~start_proc[port].processor_id) | stop_proc[port].processor_id;
-                writel(temp, stop_proc[port].global_control_reg);
-
-                /* write flush */
-                readl(stop_proc[port].global_control_reg);
-        } else {
-                dev_err(&icom_port->adapter->pci_dev->dev,
-                        "Invalid port assignment\n");
-        }
+        /* write flush */
+        readl(stop_proc[port].global_control_reg);
 
+unlock:
         spin_unlock_irqrestore(&icom_lock, flags);
 }
 
@@ -328,23 +328,25 @@ static void start_processor(struct icom_port *icom_port)
         spin_lock_irqsave(&icom_lock, flags);
 
         port = icom_port->port;
+        if (port >= ARRAY_SIZE(start_proc)) {
+                dev_err(&icom_port->adapter->pci_dev->dev,
+                        "Invalid port assignment\n");
+                goto unlock;
+        }
+
         if (port == 0 || port == 1)
                 start_proc[port].global_control_reg = &icom_port->global_reg->control;
         else
                 start_proc[port].global_control_reg = &icom_port->global_reg->control_2;
-        if (port < 4) {
-                temp = readl(start_proc[port].global_control_reg);
-                temp =
-                        (temp & ~stop_proc[port].processor_id) | start_proc[port].processor_id;
-                writel(temp, start_proc[port].global_control_reg);
 
-                /* write flush */
-                readl(start_proc[port].global_control_reg);
-        } else {
-                dev_err(&icom_port->adapter->pci_dev->dev,
-                        "Invalid port assignment\n");
-        }
+        temp = readl(start_proc[port].global_control_reg);
+        temp = (temp & ~stop_proc[port].processor_id) | start_proc[port].processor_id;
+        writel(temp, start_proc[port].global_control_reg);
+
+        /* write flush */
+        readl(start_proc[port].global_control_reg);
 
+unlock:
         spin_unlock_irqrestore(&icom_lock, flags);
 }
 
@@ -557,6 +559,12 @@ static int startup(struct icom_port *icom_port)
          */
         spin_lock_irqsave(&icom_lock, flags);
         port = icom_port->port;
+        if (port >= ARRAY_SIZE(int_mask_tbl)) {
+                dev_err(&icom_port->adapter->pci_dev->dev,
+                        "Invalid port assignment\n");
+                goto unlock;
+        }
+
         if (port == 0 || port == 1)
                 int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask;
         else
@@ -566,17 +574,14 @@ static int startup(struct icom_port *icom_port)
                 writew(0x00FF, icom_port->int_reg);
         else
                 writew(0x3F00, icom_port->int_reg);
-        if (port < 4) {
-                temp = readl(int_mask_tbl[port].global_int_mask);
-                writel(temp & ~int_mask_tbl[port].processor_id, int_mask_tbl[port].global_int_mask);
 
-                /* write flush */
-                readl(int_mask_tbl[port].global_int_mask);
-        } else {
-                dev_err(&icom_port->adapter->pci_dev->dev,
-                        "Invalid port assignment\n");
-        }
+        temp = readl(int_mask_tbl[port].global_int_mask);
+        writel(temp & ~int_mask_tbl[port].processor_id, int_mask_tbl[port].global_int_mask);
+
+        /* write flush */
+        readl(int_mask_tbl[port].global_int_mask);
 
+unlock:
         spin_unlock_irqrestore(&icom_lock, flags);
         return 0;
 }
@@ -595,21 +600,23 @@ static void shutdown(struct icom_port *icom_port)
          * disable all interrupts
          */
         port = icom_port->port;
+        if (port >= ARRAY_SIZE(int_mask_tbl)) {
+                dev_err(&icom_port->adapter->pci_dev->dev,
+                        "Invalid port assignment\n");
+                goto unlock;
+        }
         if (port == 0 || port == 1)
                 int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask;
         else
                 int_mask_tbl[port].global_int_mask = &icom_port->global_reg->int_mask_2;
 
-        if (port < 4) {
-                temp = readl(int_mask_tbl[port].global_int_mask);
-                writel(temp | int_mask_tbl[port].processor_id, int_mask_tbl[port].global_int_mask);
+        temp = readl(int_mask_tbl[port].global_int_mask);
+        writel(temp | int_mask_tbl[port].processor_id, int_mask_tbl[port].global_int_mask);
 
-                /* write flush */
-                readl(int_mask_tbl[port].global_int_mask);
-        } else {
-                dev_err(&icom_port->adapter->pci_dev->dev,
-                        "Invalid port assignment\n");
-        }
+        /* write flush */
+        readl(int_mask_tbl[port].global_int_mask);
+
+unlock:
         spin_unlock_irqrestore(&icom_lock, flags);
 
         /*