commit 80df28476505ed4e6701c3448c63c9229a50c655
author Liu Hua <sdu.liu@huawei.com> Mon Apr 07 15:38:57 2014 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Mon Apr 07 16:36:07 2014 -0700
tree c8c8a1987998a08cf6e74c34b474d8cf705e4114
parent 2aaf308b95b24649a6dcfed89cd956e972089b2a

hung_task: check the value of "sysctl_hung_task_timeout_sec"

As sysctl_hung_task_timeout_sec is unsigned long, when this value is
larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in
watchdog will return immediately without sleep and with print :

  schedule_timeout: wrong timeout value ffffffffffffff83

and then the funtion watchdog will call schedule_timeout_interruptible
again and again.  The screen will be filled with

	"schedule_timeout: wrong timeout value ffffffffffffff83"

This patch does some check and correction in sysctl, to let the function
schedule_timeout_interruptible allways get the valid parameter.

Signed-off-by: Liu Hua <sdu.liu@huawei.com>
Tested-by: Satoru Takeuchi <satoru.takeuchi@gmail.com>
Cc: <stable@vger.kernel.org>	[3.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>