watchdog: ts72xx_wdt: cleanup return codes in ioctl

There seems to be some confusion here which functions return positive
numbers and which return negative error codes.

copy_to_user() returns the number of bytes remaining to be copied but we
want to return -EFAULT.

The rest is just clean up.  get_user() actually returns zero on success
and -EFAULT on error so we can preserve the error code.  The
timeout_to_regval() function returns -EINVAL on failure, but we can
propogate that back instead of hardcoding -EINVAL ourselves.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
--

diff --git a/drivers/watchdog/ts72xx_wdt.c b/drivers/watchdog/ts72xx_wdt.c
index c9b0c62..df5dd55 100644 (file)
--- a/drivers/watchdog/ts72xx_wdt.c
+++ b/drivers/watchdog/ts72xx_wdt.c
@@ -305,7 +305,8 @@ static long ts72xx_wdt_ioctl(struct file *file, unsigned int cmd,
 
        switch (cmd) {
        case WDIOC_GETSUPPORT:
-               error = copy_to_user(argp, &winfo, sizeof(winfo));
+               if (copy_to_user(argp, &winfo, sizeof(winfo)))
+                       error = -EFAULT;
                break;
 
        case WDIOC_GETSTATUS:
@@ -320,10 +321,9 @@ static long ts72xx_wdt_ioctl(struct file *file, unsigned int cmd,
        case WDIOC_SETOPTIONS: {
                int options;
 
-               if (get_user(options, p)) {
-                       error = -EFAULT;
+               error = get_user(options, p);
+               if (error)
                        break;
-               }
 
                error = -EINVAL;
 
@@ -341,30 +341,26 @@ static long ts72xx_wdt_ioctl(struct file *file, unsigned int cmd,
 
        case WDIOC_SETTIMEOUT: {
                int new_timeout;
+               int regval;
 
-               if (get_user(new_timeout, p)) {
-                       error = -EFAULT;
-               } else {
-                       int regval;
-
-                       regval = timeout_to_regval(new_timeout);
-                       if (regval < 0) {
-                               error = -EINVAL;
-                       } else {
-                               ts72xx_wdt_stop(wdt);
-                               wdt->regval = regval;
-                               ts72xx_wdt_start(wdt);
-                       }
-               }
+               error = get_user(new_timeout, p);
                if (error)
                        break;
 
+               regval = timeout_to_regval(new_timeout);
+               if (regval < 0) {
+                       error = regval;
+                       break;
+               }
+               ts72xx_wdt_stop(wdt);
+               wdt->regval = regval;
+               ts72xx_wdt_start(wdt);
+
                /*FALLTHROUGH*/
        }
 
        case WDIOC_GETTIMEOUT:
-               if (put_user(regval_to_timeout(wdt->regval), p))
-                       error = -EFAULT;
+               error = put_user(regval_to_timeout(wdt->regval), p);
                break;
 
        default: