From: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
The kernel/sysctl.c is a kitchen sink where everyone leaves
their dirty dishes, this makes it very difficult to maintain.
To help with this maintenance let's start by moving sysctls to
places where they actually belong. The proc sysctl maintainers
do not want to know what sysctl knobs you wish to add for your own
piece of code, we just care about the core logic.
So move hung_task sysctl interface to hung_task.c and use
register_sysctl() to register the sysctl interface.
Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
[mcgrof: commit log refresh and fixed 2-3 0day reported compile issues]
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
include/linux/sched/sysctl.h | 14 +------
kernel/hung_task.c | 81 ++++++++++++++++++++++++++++++++++--
kernel/sysctl.c | 61 ---------------------------
3 files changed, 79 insertions(+), 77 deletions(-)
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index 304f431178fd..c19dd5a2c05c 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -7,20 +7,8 @@
struct ctl_table;
#ifdef CONFIG_DETECT_HUNG_TASK
-
-#ifdef CONFIG_SMP
-extern unsigned int sysctl_hung_task_all_cpu_backtrace;
-#else
-#define sysctl_hung_task_all_cpu_backtrace 0
-#endif /* CONFIG_SMP */
-
-extern int sysctl_hung_task_check_count;
-extern unsigned int sysctl_hung_task_panic;
+/* used for hung_task and block/ */
extern unsigned long sysctl_hung_task_timeout_secs;
-extern unsigned long sysctl_hung_task_check_interval_secs;
-extern int sysctl_hung_task_warnings;
-int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos);
#else
/* Avoid need for ifdefs elsewhere in the code */
enum { sysctl_hung_task_timeout_secs = 0 };
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 8cc07e7f29aa..40220dfd6fa9 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -63,7 +63,9 @@ static struct task_struct *watchdog_task;
* Should we dump all CPUs backtraces in a hung task event?
* Defaults to 0, can be changed via sysctl.
*/
-unsigned int __read_mostly sysctl_hung_task_all_cpu_backtrace;
+static unsigned int __read_mostly sysctl_hung_task_all_cpu_backtrace;
+#else
+#define sysctl_hung_task_all_cpu_backtrace 0
#endif /* CONFIG_SMP */
/*
@@ -266,11 +268,13 @@ static long hung_timeout_jiffies(unsigned long last_checked,
MAX_SCHEDULE_TIMEOUT;
}
+#ifdef CONFIG_SYSCTL
/*
* Process updating of timeout sysctl
*/
-int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
- void *buffer, size_t *lenp, loff_t *ppos)
+static int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
+ void __user *buffer,
+ size_t *lenp, loff_t *ppos)
{
int ret;
@@ -285,6 +289,76 @@ int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
return ret;
}
+/*
+ * This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs
+ * and hung_task_check_interval_secs
+ */
+static const unsigned long hung_task_timeout_max = (LONG_MAX / HZ);
+static struct ctl_table hung_task_sysctls[] = {
+#ifdef CONFIG_SMP
+ {
+ .procname = "hung_task_all_cpu_backtrace",
+ .data = &sysctl_hung_task_all_cpu_backtrace,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+#endif /* CONFIG_SMP */
+ {
+ .procname = "hung_task_panic",
+ .data = &sysctl_hung_task_panic,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "hung_task_check_count",
+ .data = &sysctl_hung_task_check_count,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ },
+ {
+ .procname = "hung_task_timeout_secs",
+ .data = &sysctl_hung_task_timeout_secs,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = proc_dohung_task_timeout_secs,
+ .extra2 = (void *)&hung_task_timeout_max,
+ },
+ {
+ .procname = "hung_task_check_interval_secs",
+ .data = &sysctl_hung_task_check_interval_secs,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = proc_dohung_task_timeout_secs,
+ .extra2 = (void *)&hung_task_timeout_max,
+ },
+ {
+ .procname = "hung_task_warnings",
+ .data = &sysctl_hung_task_warnings,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_NEG_ONE,
+ },
+ {}
+};
+
+static void __init hung_task_sysctl_init(void)
+{
+ register_sysctl_init("kernel", hung_task_sysctls);
+}
+#else
+#define hung_task_sysctl_init() do { } while (0)
+#endif /* CONFIG_SYSCTL */
+
+
static atomic_t reset_hung_task = ATOMIC_INIT(0);
void reset_hung_task_detector(void)
@@ -354,6 +428,7 @@ static int __init hung_task_init(void)
pm_notifier(hungtask_pm_notify, 0);
watchdog_task = kthread_run(watchdog, NULL, "khungtaskd");
+ hung_task_sysctl_init();
return 0;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3097f0286504..9fc6a5222cee 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -133,13 +133,6 @@ 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
- * and hung_task_check_interval_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>
@@ -2507,60 +2500,6 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec,
},
#endif
-#ifdef CONFIG_DETECT_HUNG_TASK
-#ifdef CONFIG_SMP
- {
- .procname = "hung_task_all_cpu_backtrace",
- .data = &sysctl_hung_task_all_cpu_backtrace,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
-#endif /* CONFIG_SMP */
- {
- .procname = "hung_task_panic",
- .data = &sysctl_hung_task_panic,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- {
- .procname = "hung_task_check_count",
- .data = &sysctl_hung_task_check_count,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- },
- {
- .procname = "hung_task_timeout_secs",
- .data = &sysctl_hung_task_timeout_secs,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = proc_dohung_task_timeout_secs,
- .extra2 = &hung_task_timeout_max,
- },
- {
- .procname = "hung_task_check_interval_secs",
- .data = &sysctl_hung_task_check_interval_secs,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = proc_dohung_task_timeout_secs,
- .extra2 = &hung_task_timeout_max,
- },
- {
- .procname = "hung_task_warnings",
- .data = &sysctl_hung_task_warnings,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_NEG_ONE,
- },
-#endif
#ifdef CONFIG_RT_MUTEXES
{
.procname = "max_lock_depth",
--
2.33.0
