[PATCH 3/6] Input: uinput - allow FF requests to time out

[Dmitry Torokhov]

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.torok...@gmail.com>
---
 drivers/input/misc/uinput.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

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:
-- 
2.14.1.581.gf28d330327-goog