udlfb: fix issues found with Sparse static analysis

Add __user casting, a missing copy_from_user, and proper boolean

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 16 insertions, 14 deletions

diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index 0b77af7bdf1b..37498abcd917 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c
@@ -776,14 +776,13 @@ static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 {
 
         struct dlfb_data *dev = info->par;
-        struct dloarea *area = NULL;
 
         if (!atomic_read(&dev->usb_active))
                 return 0;
 
         /* TODO: Update X server to get this from sysfs instead */
         if (cmd == DLFB_IOCTL_RETURN_EDID) {
-                char *edid = (char *)arg;
+                void __user *edid = (void __user *)arg;
                 if (copy_to_user(edid, dev->edid, dev->edid_size))
                         return -EFAULT;
                 return 0;
@@ -791,6 +790,11 @@ static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 
         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
+                struct dloarea area;
+
+                if (copy_from_user(&area, (void __user *)arg,
+                                  sizeof(struct dloarea)))
+                        return -EFAULT;
 
                 /*
                  * If we have a damage-aware client, turn fb_defio "off"
@@ -802,21 +806,19 @@ static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
                 if (info->fbdefio)
                         info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
 
-                area = (struct dloarea *)arg;
-
-                if (area->x < 0)
-                        area->x = 0;
+                if (area.x < 0)
+                        area.x = 0;
 
-                if (area->x > info->var.xres)
-                        area->x = info->var.xres;
+                if (area.x > info->var.xres)
+                        area.x = info->var.xres;
 
-                if (area->y < 0)
-                        area->y = 0;
+                if (area.y < 0)
+                        area.y = 0;
 
-                if (area->y > info->var.yres)
-                        area->y = info->var.yres;
+                if (area.y > info->var.yres)
+                        area.y = info->var.yres;
 
-                dlfb_handle_damage(dev, area->x, area->y, area->w, area->h,
+                dlfb_handle_damage(dev, area.x, area.y, area.w, area.h,
                            info->screen_base);
         }
 
@@ -864,7 +866,7 @@ static int dlfb_ops_open(struct fb_info *info, int user)
          * preventing other clients (X) from working properly. Usually
          * not what the user wants. Fail by default with option to enable.
          */
-        if ((user == 0) & (!console))
+        if ((user == 0) && (!console))
                 return -EBUSY;
 
         /* If the USB device is gone, we don't accept new opens */