| From | Jiri Slaby <> | Subject | [PATCH 3.12 083/155] hung_task: check the value of "sysctl_hung_task_timeout_sec" | Date | Tue, 7 Apr 2015 14:50:52 +0200 |
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From: Liu Hua <sdu.liu@huawei.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 80df28476505ed4e6701c3448c63c9229a50c655 upstream.
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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- kernel/sysctl.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 167741003616..6a9b0c42fb30 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -142,6 +142,11 @@ static int minolduid; static int ngroups_max = NGROUPS_MAX; static const int cap_last_cap = CAP_LAST_CAP; +/*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */ +#ifdef CONFIG_DETECT_HUNG_TASK +static unsigned long hung_task_timeout_max = (LONG_MAX/HZ); +#endif + #ifdef CONFIG_INOTIFY_USER #include <linux/inotify.h> #endif @@ -971,6 +976,7 @@ static struct ctl_table kern_table[] = { .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_dohung_task_timeout_secs, + .extra2 = &hung_task_timeout_max, }, { .procname = "hung_task_warnings", -- 2.3.4
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