Input: appletouch - fix DMA to/from stack buffer

CONFIG_DMA_API_DEBUG spotted an instance of appletouch using
an array on the stack as a DMA buffer for certain hardware.
Change it to use a kmalloc()ed buffer instead.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 18 insertions, 6 deletions

diff --git a/drivers/input/mouse/appletouch.c b/drivers/input/mouse/appletouch.c
index 454b96112f03..e0140fdc02a5 100644
--- a/drivers/input/mouse/appletouch.c
+++ b/drivers/input/mouse/appletouch.c
@@ -255,15 +255,22 @@ MODULE_PARM_DESC(debug, "Activate debugging output");
  */
 static int atp_geyser_init(struct usb_device *udev)
 {
-        char data[8];
+        char *data;
         int size;
         int i;
+        int ret;
+
+        data = kmalloc(8, GFP_KERNEL);
+        if (!data) {
+                err("Out of memory");
+                return -ENOMEM;
+        }
 
         size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
                         ATP_GEYSER_MODE_READ_REQUEST_ID,
                         USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
                         ATP_GEYSER_MODE_REQUEST_VALUE,
-                        ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
+                        ATP_GEYSER_MODE_REQUEST_INDEX, data, 8, 5000);
 
         if (size != 8) {
                 dprintk("atp_geyser_init: read error\n");
@@ -271,7 +278,8 @@ static int atp_geyser_init(struct usb_device *udev)
                         dprintk("appletouch[%d]: %d\n", i, data[i]);
 
                 err("Failed to read mode from device.");
-                return -EIO;
+                ret = -EIO;
+                goto out_free;
         }
 
         /* Apply the mode switch */
@@ -281,7 +289,7 @@ static int atp_geyser_init(struct usb_device *udev)
                         ATP_GEYSER_MODE_WRITE_REQUEST_ID,
                         USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
                         ATP_GEYSER_MODE_REQUEST_VALUE,
-                        ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
+                        ATP_GEYSER_MODE_REQUEST_INDEX, data, 8, 5000);
 
         if (size != 8) {
                 dprintk("atp_geyser_init: write error\n");
@@ -289,9 +297,13 @@ static int atp_geyser_init(struct usb_device *udev)
                         dprintk("appletouch[%d]: %d\n", i, data[i]);
 
                 err("Failed to request geyser raw mode");
-                return -EIO;
+                ret = -EIO;
+                goto out_free;
         }
-        return 0;
+        ret = 0;
+out_free:
+        kfree(data);
+        return ret;
 }
 
 /*