'uinput' Oops upon select() or poll() on 2.6.7-rc1

'uinput' Oops upon select() or poll() on 2.6.7-rc1

[Sau Dan Lee]

When  I tried  to do  a select()  or poll()  on the  char  device that
'uinput' creates for  interacting with the input system,  I get a SEGV
in my userspace program.  'dmesg' shows an Oops message.

For details, please check the bugzilla entry

http://bugzilla.kernel.org/show_bug.cgi?id=2786



-- 
Sau Dan LEE                     李守敦(Big5)                    ~{@nJX6X~}(HZ) 

E-mail: danlee@informatik.uni-freiburg.de
Home page: http://www.informatik.uni-freiburg.de/~danlee

'uinput' Oops upon select() or poll() on 2.6.7

[Sau Dan Lee]

Re-reporting this bug found 3  weeks ago, because it's still in 2.6.7.
(It was found and reported for 2.6.7-rc1.)

For details, please check the bugzilla entry

        http://bugzilla.kernel.org/show_bug.cgi?id=2786


Dmitry Torokhov has already offered a patch on 2004-05-28 12:52.

Vojtech Pavlik  said on 2004-05-28 13:59  that he has fixed  it in his
input tree.


But the bug is STILL in 2.6.7.  I don't understand.  What are the -rc*
supposed for, if bugs do not get fixed?



from Dmitry Torokhov  2004-05-28 12:52:

--- 2.6.6/drivers/input/misc/uinput.c	2004-05-11 14:57:25.793252800 -0500
+++ linux-2.6.6/drivers/input/misc/uinput.c	2004-05-28 14:42:36.922273600 -0500
@@ -279,10 +279,11 @@
 {
 	struct uinput_device *udev = file->private_data;
 
-	poll_wait(file, &udev->waitq, wait);
-
-	if (udev->head != udev->tail)
-		return POLLIN | POLLRDNORM;
+	if (test_bit(UIST_CREATED, &udev->state)) {
+		poll_wait(file, &udev->waitq, wait);
+		if (udev->head != udev->tail)
+			return POLLIN | POLLRDNORM;
+	}
 
 	return 0;
 }


-- 
Sau Dan LEE                     李守敦(Big5)                    ~{@nJX6X~}(HZ) 

E-mail: danlee@informatik.uni-freiburg.de
Home page: http://www.informatik.uni-freiburg.de/~danlee

Re: 'uinput' Oops upon select() or poll() on 2.6.7

[Dmitry Torokhov]

On Wednesday 16 June 2004 06:34 am, Sau Dan Lee wrote:
> 
> But the bug is STILL in 2.6.7.  I don't understand.  What are the -rc*
> supposed for, if bugs do not get fixed?
> 

Hi,

Given the fact that it affects exactly one person and you can avoid it by
fixing your program which is broken in this regard anyway (why would you
poll device before you create it?) I don't think it is that urgent...

I believe it will be merged when Linus does next pull. 

-- 
Dmitry