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authorLi Zefan <lizefan@huawei.com>2013-09-23 16:43:58 +0800
committerIngo Molnar <mingo@kernel.org>2013-09-23 11:10:49 +0200
commitcd64647f043e3fd3569bcf068f47f030198ff93a (patch)
treec4ff621340758e4dde72ddb8c3a63d32604c0fbb
parentd8524ae9d6f492a9c6db9f4d89c5f9b8782fa2d5 (diff)
hung_task: Change sysctl_hung_task_check_count to 'int'
As 'sysctl_hung_task_check_count' is 'unsigned long' when this value is assigned to max_count in check_hung_uninterruptible_tasks(), it's truncated to 'int' type. This causes a minor artifact: if we write 2^32 to sysctl.hung_task_check_count, hung task detection will be effectively disabled. With this fix, it will still truncate the user input to 32 bits, but reading sysctl.hung_task_check_count reflects the actual truncated value. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/523FFF4E.9050401@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--include/linux/sched/sysctl.h2
-rw-r--r--kernel/hung_task.c2
-rw-r--r--kernel/sysctl.c5
3 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index bf8086b2506e..9552afa733d8 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -2,8 +2,8 @@
#define _SCHED_SYSCTL_H
#ifdef CONFIG_DETECT_HUNG_TASK
+extern int sysctl_hung_task_check_count;
extern unsigned int sysctl_hung_task_panic;
-extern unsigned long sysctl_hung_task_check_count;
extern unsigned long sysctl_hung_task_timeout_secs;
extern unsigned long sysctl_hung_task_warnings;
extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 3e97fb126e6b..042252383fd2 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -20,7 +20,7 @@
/*
* The number of tasks checked:
*/
-unsigned long __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;
+int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;
/*
* Limit number of tasks checked in a batch.
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b2f06f3c6a3f..b24ed7f87a14 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -962,9 +962,10 @@ static struct ctl_table kern_table[] = {
{
.procname = "hung_task_check_count",
.data = &sysctl_hung_task_check_count,
- .maxlen = sizeof(unsigned long),
+ .maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = proc_doulongvec_minmax,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
},
{
.procname = "hung_task_timeout_secs",