Input: uinput - allow FF requests to time out

Previously uinput force feedback requests waited for the userspace
indefinitely, which caused users to block when uinput server process
become unresponsive. Let's establish a 30 seconds deadline for servicing
upload and erase force feedback effect actions, so that users have a
chance to abort stuck requests.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 443151de90c6..c30704fa1a06 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -149,7 +149,11 @@ static int uinput_request_submit(struct uinput_device *udev,
         if (retval)
                 goto out;
 
-        wait_for_completion(&request->done);
+        if (!wait_for_completion_timeout(&request->done, 30 * HZ)) {
+                retval = -ETIMEDOUT;
+                goto out;
+        }
+
         retval = request->retval;
 
  out: